Reliability and Probabilistic Risk Assessment - June 22, 2001


                Official Transcript of Proceedings


Title:                    Advisory Committee on Reactor Safeguards
                               Subcommittee on Reliability and Probabilistic
                               Risk Assessment

Docket Number:  (not applicable)

Location:                 Rockville, Maryland

Date:                     Friday, June 22, 2001

Work Order No.: NRC-277                               Pages 1-284

                   NEAL R. GROSS AND CO., INC.
                 Court Reporters and Transcribers
                  1323 Rhode Island Avenue, N.W.
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                          (202) 234-4433             UNITED STATES OF AMERICA
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                  RISK ASSESSMENT
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                   JUNE 22, 2001
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                ROCKVILLE, MARYLAND
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                       The subcommittee meeting was held at the
           Nuclear Regulatory Commission, Two White Flint North,
           Room T2B3, 11545 Rockville Pike, at 8:30 a.m., Dr.
           George E. Apostolakis, Chairman, presiding.
                 GEORGE E. APOSTOLAKIS       Chairman
                 MARIO V. BONACA             Vice Chairman
                 THOMAS S. KRESS             Member
           COMMITTEE MEMBERS PRESENT:  (cont'd)
                 GRAHAM M. LEITCH            Member
                 DANA A. POWERS              Member
                 WILLIAM J. SHACK            Member
                 ROBERT UHRIG                Member
                 MICHAEL T. MARKLEY
                                 I N D E X
                         AGENDA ITEM                       PAGE
           Introduction . . . . . . . . . . . . . . . . . . . 4
           NRC Staff Presentation
                 -- Introduction and Overview of Draft. . . . 5
                    NUREG-1742, Perspectives Gained
                    from the IPEEE Program
                 -- Seismic Insights. . . . . . . . . . . . .27
                 -- Fire Insights . . . . . . . . . . . . . 133
                 -- High Winds, Floods, and Other . . . . . 213
                    External Events
                 -- IPEEE-Related Unresolved Safety . . . . 234
                    Issue (USI) and Generic Safety
                    Issue (GSI) Resolution
                 -- Closing Remarks . . . . . . . . . . . . 265
           General Discussion and Adjournment . . . . . . . 269
                                                    (8:30 a.m.)
                       CHAIRMAN APOSTOLAKIS:  The meeting will
           now come to order.  This is a meeting of the Advisory
           Committee on Reactor Safeguards, Subcommittee on
           Reliability and Probabilistic Risk Assessment. 
                       I am George Apostolakis, Chairman of the
           Subcommittee on Reliability and PRA.  Subcommittee
           members in attendance are Mario Bonaca, Tom Kress,
           Graham Leitch, Dana Powers, William Shack, and Robert
                       The purpose of this meeting is to discuss
           the staff's draft Individual Plant Examination for
           External Events insights report, draft NUREG-1742. 
           The subcommittee will gather information, analyze the
           relevant issues and facts, and formulate proposed
           positions and actions, as appropriate, for
           deliberation by the full committee.
                       Michael T. Markley is the cognizant ACRS
           staff engineer for this meeting.  The rules for
           participation in today's meeting have been announced
           as part of the notice of this meeting previously
           published in the Federal Register on May 23, 2001.
                       A transcript of the meeting is being kept
           and will be made available as stated in the Federal
           Register notice.  It is requested that speakers first
           identify themselves and speak with sufficient clarity
           and volume so that they can be readily heard.
                       We have received no written comments or
           requests for time to make oral statements from members
           of the public regarding today's meeting.  
                       We will now proceed with the meeting, and
           I call upon Mr. Alan Rubin of the Office of Research
           to begin.  Alan, welcome.
                       MR. RUBIN:  Good morning.  Thank you.
                       Good morning, and thank you, Professor
           Apostolakis, members of the subcommittee.  My name is
           Alan Rubin.  I have been the project manager for the
           IPEEE program for quite a number of years, and I am
           here to present introductory comments.
                       There are other members of the IPEEE team
           who are with us this morning, including Brad Hardin
           and John Ridgely of the staff, who you will hear from
           later today, John Lehner from Brookhaven National
           Laboratories, and Steve Nowlen from Sandia National
           Laboratories.  I just want to correct a typo I think
           on the agenda for that.  Steve told me this morning he
           is not with Brookhaven.
                       By the way, there are quite a large number
           of other participants in the program, including
           contractors, the staff in both Research and NRR,
           others, some of whom are present in the audience this
           morning.  So I just want to acknowledge the
           contributions that many people have made to this
           program over the years.
                       The outline of today's meeting -- I will
           give introductory comments that will include some of
           the background on the IPEEE program, so that we're all
           talking to the same base of the objectives of the
           IPEEE program.  I'll discuss a little bit of what took
           place in the reviews of the submittals, the process
           that the staff went through in reviewing licensees'
           IPEEE analyses.  I will discuss an overview of what's
           included in the draft NUREG-1742, the insights report.
                       The second presentation will be on the
           seismic perspectives by John Lehner, then probably
           followed by the IPEEE fire perspectives given by Steve
           Nowlen.  After lunch Brad Hardin will discuss the high
           winds, floods, and other external events aspects of
           the IPEEE program.  John Ridgely will then discuss the
           resolution of IPEEE-related generic issues, generic
           safety issues, and unresolved safety issues.
                       I will then conclude the program with a
           discussion of some examples of how the IPEEE
           information has been and may be used, and then give
           some overall conclusions and observations.
                       We would like to -- the staff would like
           to get a letter, if the Advisory Committee feels it
           appropriate, on the IPEEE program.  We'll leave it up
           to you.  
                       It might be helpful to us if we can get
           some perspectives on the committee's views and whether
           the -- if there's a feeling that the program has met
           the intent of the objective of the IPEEE program,
           perhaps some comments on the uses of IPEEE information
           itself.  But it's really up to the deliberations of
           the subcommittee and the committee.
                       MEMBER POWERS:  It seems to me that the
           objectives that the agency had in asking for the IPEEE
           effort were sufficiently qualitative, that there's a
           good chance that the effort met that.  There may be
           some plants that are exceptions to that, but as a
           general rule it looks like it's a pretty easy set of
           requirements to meet.
                       There is another objective that I think we
           ought to have for the insights report itself, and
           that's to develop some intuition and understanding on
           the risks associated with external events for the
           agency's own thinking about risk-informed regulation.
                       And I wondered if you had set any
           objectives and had any -- you said you were going to
           give examples on how it might be used, but do you have
           any aspirations for what would be achieved by this
           effort in order to develop that agency's understanding
           of risk associated with these events?
                       MR. RUBIN:  Well, let me -- let me answer
           that question when I get to the examples.  But,
           basically, I think I agree with you that the -- at
           least from our view we think that the objectives of
           the IPEEE program has been met for all plants.
                       In terms of the uses of the information,
           it has been and is being used, from what I've seen, I
           think in an appropriate fashion.  Just very briefly,
           to use, in my view, the quantitative estimates of core
           damage frequencies as a measure of a plant's risk, I
           would view that with a little bit of maybe not --
           "skepticism" isn't the right word, but I'd look at
           that with a -- see what kind of analysis the licensee
           has done and what kind of a review and perspectives
           the staff has given in our staff evaluation report and
           technical evaluation reports.
                       So there's a lot of insights, I think,
           that are available if one wants to know some plant-
           specific information, both -- that's included in the
           licensee submittals, but that's only a piece of the
           picture.  I think it's very important to also look at
           what the staff has written in our staff evaluation
           report and that it include in the technical evaluation
           reports for each submittal -- to discuss the strengths
           and the weaknesses of what we see is in the
                       And although we have concluded that each
           submittal has met the intent of the IPEEE program,
           there clearly are, I'd say, differences in the
           approaches that licensees have taken.  And those
           insights are included in individual technical and
           staff evaluation reports.
                       It was not possible to bring all of those
           specific -- plant-specific insights into one document
           which we call the IPEEE insights report.  But I just
           wanted to make that point.
                       And I think, Dana, when I go through the
           applications later this afternoon in my concluding
           statements we can discuss this further, if that's okay
           with you.
                       CHAIRMAN APOSTOLAKIS:  Now, regarding the
           IPEs, since you mentioned that you would like to have
           a letter, we wrote two letters on the IPEEEs.  one was
           on the use of individual plant examinations in the
           regulatory process, and the other on the potential use
           of IPE results to compare the risk of the current
           population or plants with the safety goals.  That was
           five years ago.
                       I guess you are asking us to write a
           letter similar to the first one, the use of the IPEEE
           now in the regulatory process --
                       MR. RUBIN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  -- because we
           commented also on the quality.
                       MR. RUBIN:  Yes.  I think the first one
           rather than the latter.
                       CHAIRMAN APOSTOLAKIS:  The first one.
                       MR. RUBIN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  This.
                       MR. RUBIN:  Okay.  Some of the background,
           to be sure we're all up to speed a little bit.  The
           Generic Letter 88-20, Supplement 4, which was the
           IPEEE request for licensees to do IPEEE analysis and
           submit that information to the NRC, to identify plant-
           specific vulnerabilities to severe accidents for
           external events.  That letter was issued in June 1991. 
           Gosh, and here we are in June 2001 saying that the
           program is basically done.
                       At the same time the Generic Letter went
           out, the staff issued a NUREG report, NUREG-1407, that
           included procedural and submittal guidance for
           licensees to conduct their IPEEE analyses.  And also,
           in September 1995, there was a Supplement 5 to Generic
           Letter 88-20 that was issued that provided additional
           guidance and clarification on the seismic -- the scope
           of the seismic analysis for the IPEEEs.
                       I think we are all familiar with the
           external events that are included in the IPEEE
           program.  Clearly, seismic events; fires; you will
           hear the term HFO, which stands for high winds,
           including tornadoes and hurricanes; floods, which is
           external floods; and the O in HFO stands for other,
           which covers transportation, nearby facility
           accidents, and other plant-specific or unique types of
           external events.
                       CHAIRMAN APOSTOLAKIS:  I'm curious.  When
           you issue a letter, a generic letter, do you give a
           deadline to the licensees, or sometimes you do,
           sometimes you don't?
                       MR. RUBIN:  There was -- I think it was
           three years.  There was a number of years to respond.
                       CHAIRMAN APOSTOLAKIS:  So why is it 10
           years, then?
                       MR. RUBIN:  Well, by the time we got the
           licensees' submittals, that was I would say probably
           at least a three- to five- or six-year timeframe. 
           There were extensions, not everybody submitted at the
           same time, we couldn't -- you know, we don't have the
           resources to review them all in parallel.
                       CHAIRMAN APOSTOLAKIS:  I see.
                       MR. RUBIN:  We had some -- at least two
           dozen -- I'll get into this later -- Senior Review
           Board meetings to review the licensees' submittals. 
           We've had at least one round and often two rounds of
           requests for additional information. 
                       Writing the technical and staff evaluation
           reports is -- going through each plant review is
           probably about a two-year process from the time we
           start to writing the SER, roughly.
                       CHAIRMAN APOSTOLAKIS:  Good.
                       MR. RUBIN:  Okay.  And 10 years flies by
           when you're having fun.
                       The status of the program.  In January
           1988, the staff provided a preliminary IPEEE insights
           report to the Commission.  At that time, the report
           was based on the review -- I should say the
           preliminary review about one-third of the submittals. 
           There were 70 IPEEE submittals in total covering all
           of the operating reactors in the U.S.
                       At that time, following that preliminary
           insights report, I had given FIVE presentations to
           various ACRS subcommittees and the full committee on
           various aspects of the program, fire aspects, seismic,
           HFO aspects.  And here we are back again.  Now the
           program is basically completed.
                       We have completed reviews for all 70
           submittals.  One plant, Haddam Neck, has shut down. 
           So what we actually did, we issued 69 staff evaluation
           reports.  Included in those staff evaluation reports,
           as I said earlier, are technical evaluation reports
           which contain a lot of useful information on plant-
           specific issues and strengths and weaknesses.
                       You have in front of you -- it was passed
           out and was issued in April 2001 -- draft NUREG-1742,
           which is titled "Perspectives Gained from the IPEEE
           Program," and that was issued for public comment.  It
           has been given a very wide distribution.  We have
           distributed about 500 hard copies, including e-mail
           distribution and announcements on the -- by e-mail, on
           the website, in the Federal Register notice.
                       Copies have been sent to all utilities, to
           various stakeholders, NRC staff, and others.  The
           comment period ends on July 31st, 2001.  I should say
           as of this date we have not received any public
           comments yet, but that's not surprising.  Usually when
           there's a deadline you try to get them to get comments
           at the last minute.
                       And our schedule was to issue the final
           NUREG-1742 in October 2001, taking into account public
                       MEMBER LEITCH:  Changes in procedures, and
           what not, made by the utilities as a result of this
           study, changes there were -- a number of utilities
           made various changes to procedures, in some cases
           hardware.  Were those changes voluntary on the part of
           the utility?
                       MR. RUBIN:  Yes.
                       MEMBER LEITCH:  And it seems to me that
           some of the insights here could be -- other utilities
           could benefit from -- if Utility A made certain
           changes, Utility B may have the same situation and not
           have made those changes.  This is just distributed to
           the utilities and hope that they will see what has
           been done here and try to apply it to their particular
                       MR. RUBIN:  The candidate -- there's
           nothing that the NRC is requiring or focusing on that. 
           But I was going to get to it -- in Volume 2 of the
           draft report NUREG-1742, our plant-specific
           information, the plant-specific tables, and the
           details, the types of improvements that each utility
                       One of the things consciously we tried to
           do, with staff and the Senior Review Board in
           reviewing the submittals, is not just on improvements,
           but where there are similar plants why there were
           differences.  You know, why does one plant come up
           with a certain area that is a large contributor to
           risk and another one doesn't?  Or another plant may
           have analyzed certain aspects of the IPEEEs
           differently, and we focused on that significantly.
                       So, I mean, in terms of what a licensee
           chooses to do, the improvements are voluntary.  The
           Generic Letter itself is not a requirement.  The
           Generic Letter is a request.
                       VICE CHAIRMAN BONACA:  But going on the
           same issue, for example, in the fire area there were
           only three utilities, I believe, that had identifiable
                       MR. RUBIN:  Yes.  Two utilities, three
           units, yes, correct.
                       VICE CHAIRMAN BONACA:  And one of them
           identifiable vulnerabilities in the turbine building,
           if I remember, that were significant.  And there were
           changes made to address those problems.
                       That plant has a number of sister plants
           with identified vulnerabilities.  There were also some
           vulnerabilities tied to the design -- safety cables
           coming through the turbine building area in locations. 
           Did you go back and check about sister plants to see
           if they had the same configuration concern or just
           simply was left to -- unaddressed?  I mean --
                       MR. RUBIN:  Well, we'll get into the
           vulnerabilities later on.  But just let me briefly say
           of those two -- three units, okay, two reactors at one
           site, and one at another site, the first one was Quad
           Cities, which we have -- I have talked about to this
           committee before.
                       That first analysis that the utility did,
           they went -- the licensee went back and redid their
           IPEEE, the fire analysis, in its entirety.  There was
           a lot of visibility.  There were a lot of discussions
           with the staff.  There were a lot of fire inspections. 
           There was quite a host of activities, both at the
           utility and at the staff when this fire issue came up
           several years ago.
                       The licensee revised their analysis.  We
           went out and did a site audit -- the staff and our
           contractors -- of the revised analysis.  We walked
           around the plant.  We went to see what they did.  And
           we felt they did a very good job, in fact.  Their
           first analysis was very, very conservative, I would
           say.  That's when they came up with the fire
           vulnerability.  There was a core damage frequency of
           five times 10-3 just from fires.  And that was a
           turbine building fire.
                       What we then -- we looked at very
           carefully other plants that -- whether they even
           looked at or discussed whether the cables -- safety
           cables running through the turbine building.  And
           effectively as a result of our reviews, we questioned
           a licensee that did not identify a vulnerability in
           their turbine building, and as a result of the staff
           questions they discovered one and made changes.
                       VICE CHAIRMAN BONACA:  Okay.  So --
                       MR. RUBIN:  So that's sort of a short
           summary of those vulnerability issues.  
                       I'm sorry if I'm stealing your thunder,
           Steve, but the question came up.
                       VICE CHAIRMAN BONACA:  No.  It's -- I
           mean, understanding what the staff did with the
           information regarding other licensees.
                       MR. RUBIN:  And by the way, that is an
           issue -- turbine building fires, that you brought up,
           is a part of the aspects of the fire risk research
           program also as well.
                       Let me just set the stage.  The objectives
           of the IPEEE program -- and Dana mentioned earlier
           they seemed like kind of -- I don't know if a "low
           bar" is correct, but they are not quantitative
           objectives.  Let me just read them.  
                       These were straight out of NUREG -- the
           Generic Letter 88-20, and these objectives were all
           for licensees.  There was to develop an appreciation
           of severe accident behavior for their plants.  We hope
           they would understand the most likely severe accident
           sequences that could occur at their plants under full
           power operating conditions.
                       The licensees were expected to gain a
           qualitative understanding of the overall likelihood of
           core damage in fission product release.  It was not
           quantitative CDF estimates that we were after.  In
           many cases, we did get quantification of core damage
                       And, lastly, and very importantly, I
           should say, licensees would voluntarily reduce, if
           necessary, the overall likelihood of core damage in
           fission product release when making modifications, and
           plant improvements, be it either hardware or
           procedural improvements, that could help prevent or
           mitigate such severe accidents.
                       CHAIRMAN APOSTOLAKIS:  I guess I have a
           little of a problem with the qualitative understanding
           of the likelihood.  That means roughly what it is. 
           That's what it means?
                       MR. RUBIN:  It means we wanted them to
           understand what the dominant contributors were.
                       CHAIRMAN APOSTOLAKIS:  It says
                       MR. RUBIN:  Right.  Correct.
                       CHAIRMAN APOSTOLAKIS:  It's a little bit
           difficult to --
                       MR. RUBIN:  Would you have liked a
           different term or --
                       CHAIRMAN APOSTOLAKIS:  Somebody at one
           point asked a physicist to gain a qualitative
           understanding of the speed of light.
                       I don't know.  Go ahead.
                       MEMBER KRESS:  It's fast.
                       CHAIRMAN APOSTOLAKIS:  What?
                       MEMBER KRESS:  It's fast.
                       MEMBER POWERS:  Very fast.
                       MEMBER KRESS:  Okay.  You're right.
                       MR. RUBIN:  Let me talk a little bit about
           the IPEEE review process itself.  After we received
           submittals from licensees, they were reviewed to
           determine whether the licensee met the intent of the
           Generic Letter.  That was clearly focused on the four
           objectives that I discussed in the previous slide, see
           whether the licensees followed the guidance that was
           given in NUREG-1407, to see whether there were gaps or
           weaknesses, and that they did a thorough job in
           covering the different aspects of each of the areas of
           the IPEEE.
                       The review process itself started with
           initial screening reviews where we focused on the
           quality and completeness of the submittals.  And a
           very important aspect --
                       MEMBER POWERS:  When you use the --
           focused on the quality, what does that mean?
                       MR. RUBIN:  It means what we did not do,
           we did not try to validate or verify the quantitative
           results, go back and check calculations that were
           included in the analysis.  We wanted to see if they
           were -- if they included the important aspects of the
           program, but we didn't go and do a quality assurance
                       MEMBER POWERS:  You looked at the index to
           see if they touched on the right topics?
                       MR. RUBIN:  Correct.
                       MEMBER POWERS:  Okay.  
                       MR. RUBIN:  And certainly, when there was
           information that looked either inconsistent, we raised
           questions.  If they did not, for example, use
           appropriate values, we raised questions, if we thought
           those could contribute to a better understanding of
           dominant contributors to risk.  And you have several
           examples of those later on in --
                       MEMBER POWERS:  I have to say that in the
           text itself where you have highlighted those areas
           where it goes -- the reviewers questioned this, and
           they went back, that was very helpful.
                       MR. RUBIN:  Okay.  Thank you. 
                       Let me just give an example.  I think
           examples help.  But there was some generic guidance
           that industry had put out, fire PRA implementation
           guide that EPRI -- that staff had not reviewed.  And
           we went through quite an extensive review process with
           industry on a generic basis to resolve those
           questions, and it resulted in some additional and
           improved guidance to utilities to respond to our RAIs.
                       An example is in the fire area on the use
           of quantitative values now for heat release rates from
           cabinet fires, heat loss factors, and analysis of room
           heat-up calculations as a result of a fire.  So I
           should -- you know, it was not that we didn't look at
           the quantitative information in the IPEEEs, but we
           didn't go back and doublecheck that, yes, they came up
           with the CDF estimates and we agreed with it.
                       I mentioned earlier we did also have a few
           plants, selected plants -- four, in fact -- where we
           had site audits.  These were additional reviews that
           were beyond the screening analysis.  For some plants
           which either had poorly documented analyses and the
           licensees asked us to come to their site, or there
           were various technical issues that were in the
           reviewer's mind.
                       One of these site visits was to Quad
           Cities as a result of their fire analysis.  They had
           a very high core damage frequency estimate for fires. 
           Just another example, we had a site visit to
           Susquehanna.  They were on the other extreme.  They
           had an extremely, extremely low core damage frequency
           estimate, on the order of 10-9 for fires.
                       MEMBER POWERS:  So why can't we all just
           follow Susquehanna's lead?  That sounds good to me.
                       MR. RUBIN:  They did, as a result of our
           visit at Susquehanna, revise their analysis.  They
           came up with a couple orders of magnitude higher
           estimate of core damage frequency, still on the low
                       But we felt after our site audit that they
           had identified the dominant -- where the dominant
           areas were, and they actually made some procedural
           improvements there as a result of that.  So we
           considered that a success.
                       I mentioned that there was a Senior Review
           Board, which was a very important part of our review
           process.  The Senior Review Board was comprised of NRC
           staff and contractors.  Many of them are here in the
           audience, and you will hear two presentations this
                       In the seismic area, that included Mike
           Bohn of Sandia National Laboratory and T.Y. Chang of
           the staff, who is in the audience.  In the fire area,
           it included Steve Nowlen from Sandia National Lab, who
           will hear from later, Ed Connell, who is sitting over
           here from NRR, and Nathan Siu from the Office of
           Research who is also in the audience.
                       And the high winds, floods, and other
           areas included Mike Bohn, also from Sandia, and Rob
           Kornasiewicz who has since retired.
                       But for a large part we had most of these
           reviewers over the entire extent of the review process
           which was very, very helpful, very useful.  That
           provided both technical advice on the scope and
           consistency of the individual reviews, and, more
           importantly, helped to provide assurance that
           vulnerabilities weren't overlooked.  
                       There were a lot of discussions back and
           forth in these Senior Review Board meetings, and there
           were at least two dozen of them over the course of the
           years focusing on RAIs and what were important issues
           and important questions to pursue with licensees.
                       VICE CHAIRMAN BONACA:  Just going back
           just for a question on technical decisions.  Does that
           mean if you had a surrogate element --
                       MR. RUBIN:  In a seismic.
                       VICE CHAIRMAN BONACA:  -- in a dominant --
           yes, in seismic, for example, you didn't consider that
           a technical deficiency, did you?
                       MR. RUBIN:  No, because that was a
           methodology that was approved.  We considered that a
           weakness, that you would not be able to -- in that
           group of -- if the surrogate element came up to be a
           dominant contributor, you would not be able to
           identify what element that was at the plant.
                       But sometimes if the overall risk were
           low, even if the surrogate element is high, we felt it
           may not be worth pursuing -- may not be necessary to
           pursue.  But it is pointed out so that in terms of,
           I'd say, uses or applications of the IPEEEs, for
           example, for risk-informed activities, if there is a
           licensee that comes in with a request in the seismic
           area, and that plant -- particular plant has a
           surrogate element as a dominant contributor, it might
           be hard, difficult, to determine, you know, should
           they get some relief from some aspects in the seismic
                       So that information is -- I felt was very
           important and very useful, and it is included in all
           of the technical evaluation reports, if that were the
           case.  And, in fact, it is even included in Volume 2
           of NUREG-1742, the dominant contributors, where there
           are surrogate elements.
                       VICE CHAIRMAN BONACA:  But would that give
           you some kind of indication of the quality of the PRA?
                       MR. RUBIN:  It was an accepted approach. 
           I don't know if -- it was nice when the surrogate
           element did not come up to the dominant contributor,
           which was the case most of the time.
                       VICE CHAIRMAN BONACA:  Okay.
                       MR. RUBIN:  But we didn't require
           licensees to go back and redo an analysis of those.
                       Just to touch base on the NUREG report,
           the draft 1742.  Volume 1 has the generic insights,
           generic types of information primarily, and Volume 2
           is a plant-specific database -- I call it -- from the
           IPEEE program.  The report itself describes the
           overall process and the findings in each of the major
           areas of the program.  
                       It discusses identified vulnerabilities,
           includes information on the quantitative findings,
           such as the range of core damage frequency estimates
           and the dominant contributors to plant risk in each of
           the areas.  It touches base and discusses the plant
           modifications and improvements that have been
           implemented or planned for each of the licensees.
                       It talks about the overall strengths and
           weaknesses.  Each plant-specific TER discusses those. 
           But in the insights reports also we discuss the
           overall strengths and weaknesses and the very general
           stance and the various methodologies that we used in
           terms of models and assumptions for the analyses.
                       An important area that you will hear about
           later is the resolution of the external event related
           generic and unresolved safety issues that were, I'd
           say, a challenging part of the review process which
           we've included in the IPEEE program.
                       The plant-specific database I mentioned. 
           The report talks about the success in meeting the
           intent and the objectives of the IPEEE program and
           includes examples which I will discuss later on this
           afternoon of the uses of IPEEE information by both
           industry and the NRC.
                       If there are no further questions, that
           completes my introductory comments, and we can
           continue on with the program, go into -- John Lehner
           will discuss the seismic reviews.
                       MR. LEHNER:  Good morning.  I'm John
           Lehner from Brookhaven National Laboratory, and I
           coordinated the effort at Brookhaven to review the
           seismic portion of the IPEEEs and collect the
                       I have also listed there some of the other
           contributors of Brookhaven, the reviewers of the
           individual submittals.  And I should also mention that
           the first 20 plants were actually reviewed by ERI,
           Energy Research Incorporated.
                       What I want to present is an introduction
           and background on previous seismic programs, how the
           IPEEE relates to those programs, and discuss the
           vulnerabilities that were -- the way vulnerabilities
           were treated in the seismic portion of the IPEEEs and
           also discuss the improvements that occurred because of
           the seismic reviews -- I mean, the seismic reviews of
           the licensees.  
                       Then I'll talk about some of the
           perspectives of the actual analyses, first discussing
           those elements which were common to the two types of
           analyses, and then go into the particular perspectives
           from the PRA analyses that were conducted, and then
           the seismic margin analyses that were conducted.
                       Finally, I'll make some comments about
           some of the perspectives on the methodologies used,
           and wind up with some conclusions.
                       Alan Rubin put up a slide that indicated
           the objectives of the IPEEE program, and this just
           summarizes the objectives of the insights program as
           it applies to the seismic portion.  Basically, we
           wanted to look at the processes used and the findings
           that the licensees had when they conducted their
           analyses, look at the plant improvements that came out
           of the seismic portion of the IPEEE program, look at
           plant-specific design and operational features as they
           might relate to the site-specific seismic hazards, and
           describe the strengths and weaknesses of particular
           methodologies, and, finally, also look at the extent
           to which the licensees met the intent of Supplement 4
           to the Generic Letter.
                       Again, as was mentioned by Alan Rubin, the
           insights program did not attempt to validate the
           results of the licensees' submittals.
                       MEMBER KRESS:  If one wanted to do that,
           how would you go about it?
                       MR. LEHNER:  To validate the results of
           the submittals?
                       MEMBER KRESS:  Yes.
                       MR. LEHNER:  I think you'd need a more
           indepth review than these screening reviews that we've
           conducted, perhaps by duplicating selective
           calculations, things like that, which were not carried
           out in our screening review.
                       CHAIRMAN APOSTOLAKIS:  How would you
           validate the fragility curves?
                       MR. LEHNER:  Well, I mean, there's
           obviously a lot of uncertainty in the fragility
           estimates.  And, of course, for the IPEEE program, the
           NUREG-1407 allowed the use of a mean fragility curve
           as well as a mean hazard curve.  So I think in most
           PRA applications for the IPEEE the licensees basically
           developed point estimates by using these mean curves.
                       I think some of them had previously
           existing PRAs where you probably had a more -- carry
           along more uncertainty, let's say.  But for the
           IPEEEs, they really use -- they were allowed to use
           the mean fragility curve.
                       MEMBER KRESS:  How do you feel about
           technical justification for that?
                       MR. LEHNER:  For the use of the mean
           fragility curve?
                       MEMBER KRESS:  Yes, for mean fragility and
           mean hazards, and combining the two to get a --
                       MR. LEHNER:  Well, I mean, it -- I think
           for achieving the objectives of the IPEEE program, I
           think it's a valid approach.  I think you have to --
                       MEMBER POWERS:  Your text seems to be
           fairly critical.  I mean, it says -- I quote, "And the
           use of simplified fragilities may have obscured
           findings related to dominant contributors to seismic."
                       MR. LEHNER:  Well, I think that refers to
           the fact that some of the licensees -- well, some of
           the analyses, the assumptions that were made for the
           uncertainty and getting the -- I mean, you still have
           to assume a combined beta value and --
                       MEMBER POWERS:  Combined beta value or
           not, this seems to call into question that Mr. Rubin
           said, that the study satisfied the objectives of the
           IPEEE effort.
                       MR. RUBIN:  Let me just add one thing. 
           These were instances in our reviews of individual
           plants where the staff had asked for licensees to
           submit examples of their calculations and analyses,
           because we wanted to get some confidence if we had
           some questions on a particular plant, where the
           reviews might have been sort of on the margin, the
           kinds of analyses and we did look at those.  
                       We didn't validate the results.  We
           actually got their calculations and looked at that as
           part of the review, not across the board for each
           plant, but for some selected plants.
                       MEMBER POWERS:  Well, I thought one of the
           objectives was to understand what the dominant
           contributors to the various hazards were.  And yet
           here it says that using these simplified approaches to
           fragility may have obscured findings related to the
           dominant contributors to seismic CDF.
                       I mean, it seems to say that they didn't
           do it.  Maybe I'm misreading the sentence, but it
           seems to say these things didn't satisfy the objective
           of the IPEEE.
                       CHAIRMAN APOSTOLAKIS:  What page is that
                       MEMBER POWERS:  You can find it in a
           couple of places, George.  But, in particular, on
           page 20, second bullet from the bottom.
                       MR. LEHNER:  I think, you know, it depends
           how you interpret that statement.  The "may have
           obscured" I think is not meant to say that it had not
           necessarily met the objective but that --
                       MEMBER POWERS:  It's plain language.  I
           mean, "may not have met," I mean, you can cast it any
           way you want to.  Either it did or it didn't.  And
           this says it didn't.
                       CHAIRMAN APOSTOLAKIS:  Well?
                       MR. LEHNER:  Well, I mean, the -- given
           the limited objective of the Generic Letter, perhaps
           that is too strong a statement.  If you feel that
           that's the -- that's what it says, then that's --
                       VICE CHAIRMAN BONACA:  Well, let me just
           say that that was an issue I didn't raise.  But
           combined with the issue of the surrogate --
                       MR. LEHNER:  Right.
                       VICE CHAIRMAN BONACA:  -- in some cases
           being the dominant, etcetera, etcetera, there are a
           lot of almost disclaimers within the text of this
           NUREG as to the adequacy of any conclusions.
                       I mean, for example, when you compare as
           a timeline CDF, due to seismic for plants, you get to
           the conclusion that there hasn't -- you know, that
           seems as if the programs have improved the older
           plants such that -- that's rich because we know that
           for the newer plants, really, they were not evaluated
           for the true strength that they have.  I mean, there
           were some limits that they used to perform the
                       So I'm only saying that to reinforce what
           Dana said, just there are a lot of disclaimers to the
           text that gives you a sense of, well, this is very,
           very soft.
                       MR. LEHNER:  Well, I think the disclaimers
           were put in there to ensure that if the -- these
           results were used for other licensing issues that
           there are a lot of caveats to be observed here.
                       That's the reason for the disclaimers, not
           to leave the impression that the reviews that were
           conducted to see if they met the Generic Letter
           concluded that these analyses were then validated for
           licensing issues.  So I think that's why you have the
                       VICE CHAIRMAN BONACA:  And the text
           correctly identifies the methodological issues,
           page 244, you know.  But one is -- there is a good
           evaluation there, there is a good description, but one
           is left with questions regarding the conclusions being
           drawn from figures and tables, and so on.
                       MEMBER POWERS:  Are we going to discuss
           more on fragilities?  Is this the appropriate time to
           discuss more on fragilities?
                       MR. LEHNER:  It probably is, yes.
                       MEMBER POWERS:  There's this provocative
           thing that says, "UHS shapes for component fragilities
           calculated appear uncharacteristic when compared to
           conventional spectrum shapes derived from observed
           earthquakes."  Point number 1.  Point number 2, "As a
           result, seismic analyses using UHS spectra resulted in
           significant reduction in seismic demand as compared to
           corresponding design basis calculations."
                       Well, I can certainly understand why the
           design basis calculations might have a greater demand,
           but it -- I mean, when it says that the UHS shapes for
           component facilities are uncharacteristic, what are
           you telling me?  These are some figments of somebody's
                       MR. LEHNER:  Well, my understanding is
           that I guess a problem there is that for the eastern
           U.S. -- this is only true of the eastern U.S. plants. 
           I mean, the western U.S. plants have UHSs that seems
           appropriate.  But perhaps because of the lack of
           earthquake data the -- that's available for the
           eastern U.S. --
                       MEMBER POWERS:  It says it is making the
           comparison with observed earthquakes.  Okay?  I mean,
           that's what's interesting about the statement.  It
           says you've got a fragility curve, has a spectrum
           that's uncharacteristic -- that's different from what
           you observe for earthquakes.  I would assume that that
           would be a fatal flaw.  Apparently not.
                       MR. LEHNER:  Well, our reviews did not --
           we didn't go back and -- we didn't have the ability to
           go back and see how these UHS spectra were established
           by the plants.
                       MEMBER POWERS:  If somebody uses something
           that doesn't match well with experimental data, I
           mean, it doesn't strike me that that is maybe the best
           possible analytic technique.
                       MR. LEHNER:  Well, I would agree with you.
                       MEMBER POWERS:  Right.  It doesn't go
           without passing.  You said something here about that.
                       MR. LEHNER:  Right.  I think that's one of
           the methodological issues that we've focused on.
                       MEMBER POWERS:  Yes, I think there is a
                       CHAIRMAN APOSTOLAKIS:  Well, is this
           appropriate to ask, about the methodological issues?
                       MR. LEHNER:  I have a slide.
                       CHAIRMAN APOSTOLAKIS:  You have a slide.
                       MR. LEHNER:  Yes.  Well, just by way of
           background, this slide just discusses some of the
           regulatory bases for seismic designs of nuclear
           powerplants.  10 CFR Part 20, Appendix A, General
           Design Criteria 2, talks about protection against
           natural phenomena.  Obviously, earthquakes is one of
                       The idea of a safe shutdown earthquake is
           in Appendix A of 10 CFR Part 100.  And, of course, the
           NRC has issued a standard review plan with many
           updates and numerous regulatory guides that have been
           issued on seismic issues as this area has evolved.
                       It's worthwhile mentioning some of the
           seismic programs in the past that sort of led up to
           the IPEEE program.  The systematic evaluation program
           recognized that some of the earlier plants had been
           designed before seismic design criteria had really
           matured, so that went back and looked at some of those
                       Bulletin 80-11 looked at specifically
           masonry and block wall issues that applied to -- in
           nuclear plants.  Then, the Charleston earthquake issue
           or the eastern U.S. seismicity issue of course raised
           the point that the U.S. Geological Survey informed the
           NRC that there may be higher seismicity in the eastern
           -- in some of the eastern U.S. sites than originally
                       And this led to the development of hazard
           curves by Lawrence Livermore Laboratory and also by
           EPRI for the various nuclear plant sites in the
           eastern U.S.  And these hazard curves were then used
           in the IPEEE for those plants that did seismic PRAs.
                       MEMBER KRESS:  My understanding is is they
           really all use the EPRI curves.
                       MR. LEHNER:  They actually used both.  I
           think two plants actually only used the Livermore
           curves, the revised Livermore curves.  As you know,
           the Livermore curves were then later revised in I
           think '94.  But most plants used the EPRI curves as
           their base case, and then used the Livermore curves as
           a sensitivity.
                       And they were asking -- I think NUREG-1407
           actually asked that both sets of hazard curves would
           be used.  And it turned out, as I'll talk about later
           on, that it did not make a significant difference in
           the core damage frequency or in the dominant
                       MEMBER KRESS:  That raises a question of
           justification of using the LLNL curves as a
           sensitivity then.  Is that a justified use of them? 
           Can you technically justify that as a use for
           sensitivity?  I mean, why stop there, is what I'm
           saying, in terms of sensitivity.  How do we know they
           balance the uncertainty some way?
                       MR. LEHNER:  Well, no, I mean, as I said,
           the -- you know, the guidance in NUREG-1407 allowed
           the use of mean fragility and mean hazard curves and
           only asked for a use of the -- of both the EPRI and
           Livermore hazard analyses.  I don't claim that it's a
           comprehensive uncertainty analysis, certainly.
                       MEMBER KRESS:  What's bothering me is I'm
           afraid people are going to go back and misuse that as
           an uncertainty distribution.
                       CHAIRMAN APOSTOLAKIS:  Which one?  This? 
           The Livermore curves do have uncertainty in them. 
           They present families of curves.
                       MEMBER KRESS:  I know.  But they use the
                       CHAIRMAN APOSTOLAKIS:  Oh, they use the
                       MEMBER KRESS:  Yes.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MEMBER KRESS:  And I'm afraid that's going
           to be misused as an uncertainty.
                       CHAIRMAN APOSTOLAKIS:  Oh, all right.  All
                       MEMBER KRESS:  When, really, you ought to
           go to the full uncertainty in the Livermore curves and
           propagate it through.  But --
                       CHAIRMAN APOSTOLAKIS:  But that wouldn't
           be an IPEEE, then.  I mean, that's a major work, piece
           of work to do that.  I mean, you are doing full scope --
                       MEMBER KRESS:  What I'm worried about is
           misuse of the IPEEE results later on.
                       CHAIRMAN APOSTOLAKIS:  You may think that
           you have a bound when, in fact, you don't.
                       MEMBER KRESS:  Yes.
                       MR. LEHNER:  I agree with you that the --
           using the -- both sets of curves is simply a -- you
           know, it's an interesting comparison, but it
           doesn't --
                       MEMBER KRESS:  Well, it doesn't make much
           difference, it doesn't seem like --
                       MR. LEHNER:  Right.
                       MEMBER KRESS:  -- like you said, except
           for one plant I think it was --
                       MR. LEHNER:  Yes.
                       MEMBER KRESS:  -- which surprised me.  Do
           you know why that one plant made such a big
                       MR. LEHNER:  Actually, I don't, no.  I
           mean, I think -- are you talking about the Seabrook?
                       MEMBER KRESS:  Yes, I think it was
                       MR. LEHNER:  There was like an order of
           magnitude difference --
                       MEMBER KRESS:  An order of magnitude
                       MR. LEHNER:  -- in the CDF, yes.  Yes. 
           Unfortunately, Seabrook was not -- well, we at
           Brookhaven did not review Seabrook in detail, so we're
           -- I'm not sure why that was.
                       The other seismic program, of course, is
           the USI A-46 program, which looked at the seismic
           adequacy of electrical and mechanical equipment in
           plants.  And that program was actually coordinated
           with the IPEEE program in many plants, and the
           procedures there developed by the seismic
           qualification utility group, the GIP, the generic
           implementation procedures for seismic verification of
           equipment, was also used in the IPEEE walkdowns quite
           a bit.
                       Then, of course, the A-46 was a licensing
           program, whereas the IPEEE program is not.  But the
           IPEEE program then, as I said, was coordinated with
           A-46.  And, of course, under A-46 you also had the
           A-17, which was the spatial interaction issue, and the
           seismic capability of above-ground tanks, A-40.
                       Also subsumed in the IPEEE program were
           the external event part of A-45 and the Generic
           Issue 131 for the in-core flux mapping system
           applicable for Westinghouse plants.  You'll hear more
           about the USIs and GSIs in this afternoon's
                       CHAIRMAN APOSTOLAKIS:  Now, let me
           understand.  Maybe you said it and I missed it. 
           Important seismic-related programs undertaken by the
           NRC and industry -- what does that have to do with the
           IPEEE?  These were undertaken as a result of the
           findings, or there were --
                       MR. LEHNER:  No, no.  These were things
           that led up to the IPEEE.
                       CHAIRMAN APOSTOLAKIS:  Oh, way back.
                       MR. LEHNER:  Yes.  Yes.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. LEHNER:  And as I said, in other
           words, the hazard curves used in the IPEEE came out of
           the eastern U.S. seismicity issue.  And the A-46
           program -- a lot of plants -- for the A-46 program
           older plants had to evaluate their electrical and
           mechanical equipment, and they did it via a --
           developing a HCLPF for the plant, which is similar to
           what they would do in a margin analysis.
                       They also developed this -- I'll talk
           about this a little bit more later on, but this
           success paths idea from EPRI.  So when it came time
           for the IPEEE, a lot of plants that used margin
           analysis used the A-46 analysis as their basis and
           built a little bit on that to satisfy the IPEEE
                       MEMBER KRESS:  Are you going to talk about
           the HCLPFs any later, or is somebody?  The question I
           have is, we had one of our fellows do a study, and he
           concluded that you can correlate HCLPFs with actual
           effects on CDF.  But if I look at the comparison of
           the plants that did both the HCLPF and a CDF, I don't
           see that correlation.  And I was wondering if -- it
           raises a question in my mind, was our fellow wrong, or
           is there something wrong with the PRA or the HCLPF
           analysis in the IPEEE?
                       MR. LEHNER:  Well, I think there's a lot
           of --
                       MEMBER KRESS:  It could be both, I guess.
                       MR. LEHNER:  There's a lot of factors that
           enter into that.  I mean, you -- if you derive the
           HCLPF from the PRA, then, I mean, there is -- I mean,
           in the margin analysis, most of the HCLPFs were
           derived by this CDFM method, the conservative
           deterministic failure method, whereas if you're
           deriving it from the PRAs then you are -- you are
           deriving it from the fragility curves.
                       And, I mean, ideally, if you did
           everything consistently you'd get similar results. 
           But I think that -- I know the -- if you're talking
           about the figure that we have --
                       MEMBER KRESS:  I forget which figure that
                       MR. LEHNER:  Yes.  I think you have to be
           careful about the assumptions that went into those
                       So the two analysis methods -- we've
           already touched on this -- that the guidance in
           NUREG-1407 allowed for were a margin analysis or a
           seismic PRA, and they were both, of course, ways of
           comparing seismic demand versus seismic capacity of
           the important SSCs in the plant.
                       They both involved comprehensive
           walkdowns, and they were both ways of identifying
           plant vulnerabilities.  And the 1407 guidance also
           called for at least a qualitative containment
           performance analysis.
                       The seismic PRA, as I said, 1407 allowed
           mean hazard curves or mean fragilities, but it also
           called for some enhancements in the sense that you had
           to look at relay chatter, soil liquefaction if it
           happened to be applicable at the site, and it also
           asked -- all this was optional -- that -- that plants
           with a SPRA calculator HCLPF, but most plants did not
           report a HCLPF that conducted the seismic PRA.
                       MEMBER POWERS:  Let me ask you a question
           about soil liquefaction.  Were there any constraints
           of what the licensee did there?  I mean, do you have
           a standard for how to treat soil liquefaction
                       MR. LEHNER:  No.  I think that's one of
           the things that we mentioned, that there really
           doesn't seem to be an accepted methodology or accepted
           guidelines for, you know, what's an adequate soil
                       MEMBER POWERS:  And so you -- whatever
           they did you just kind of had to accept?
                       MR. LEHNER:  That's right.
                       MEMBER KRESS:  Does that raise a need for
           -- if we actually wanted to put seismic PR
           contributions in the PRAs, is that a need that's
                       MR. LEHNER:  Well, I think some plants
           actually identified some problems in that area.  Of
           course, you know, a -- I think the question is:  what
           do you do about that?  I mean, it's a very difficult
           problem to fix.
                       CHAIRMAN APOSTOLAKIS:  Now, most plants I
           understand did margin analyses, didn't they?
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  Is there a big
           difference in terms of resources required between
           doing a seismic PRA and a seismic margin analysis?
                       MR. LEHNER:  Yes, I believe so.
                       CHAIRMAN APOSTOLAKIS:  I mean, but is
           there a big difference in the benefits as well?  I
           mean, it seems to me the margin analysis, after you've
           done it, you've done it and it shows that you don't
           have any major problems, it's useless.  
                       And you can't use any of that in
           Regulatory Guide 1.174.  Nothing.  I mean, you don't
           have an estimate of the core damage frequency, so you
           save some money but you end up with nothing.
                       MR. LEHNER:  Well, yes, that's an
           interesting point.
                       CHAIRMAN APOSTOLAKIS:  I don't know why
           people prefer these things, because perhaps we don't
           insist that they use a complete PRA when they request
           other things so they could get away with it, because,
           you know, it's the same thing with FIVE on fires.
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  After you do it,
           unless you go on and do a PRA on the unscreened
           locations, you don't have results that can be used in
           the future.  You just showed that you don't have
           vulnerabilities according to these rules.
                       MEMBER KRESS:  One way to use those may be
           -- Bill Shack's take on this -- is if the margins
           analyses and the FIVE analyses shows you don't have to
           worry about fire or seismic, then you don't have to
           include them in your 1.174.
                       CHAIRMAN APOSTOLAKIS:  Well, then, if
           that's the case, I think you need a much more detailed
           review than these guys were allowed to give those --
                       MEMBER POWERS:  It seems to me, Tom, I
           mean, this is like analyzing one sequence.  You come
           out and you find out, well, that sequence is a 10 to
           the minus sequence, so I threw it away.  And I, in
           fact, define my sequences so that they're all less
           than 10-6, so I can throw them away, so I have zero
           risk from the plant.  I mean --
                       MEMBER KRESS:  You're exactly right. 
           Especially if you're going to use importance measures,
           you've got to worry about that, too.
                       MEMBER POWERS:  Yes.  And that's what
           worries me here is that we're doing all of this
           categorization of equipment, and we're not getting any
           benefit out of this for the risk achievement or risk
           reduction worth with respect to seismic and fire and
           that categorization.  And we'll never get it.
                       MEMBER KRESS:  Yes.  I was wondering if
           anybody would bring up the concept that just because
           it's relatively low contribution to the CDF, it may
           not be a relatively low contribution to the
           derivative, and that's what you're really finding in
           1.174 is the derivative.  And so, but anyway --
                       CHAIRMAN APOSTOLAKIS:  Well, I think we
           should clarify this.  Either we go back to 1.174 and
           say external events are not to be included, or we do
           a serious job here.  I mean, you can't have it both
                       MEMBER KRESS:  If the intent is to use
           this in 1.174, that might not be a --
                       CHAIRMAN APOSTOLAKIS:  Well, 1.174 says
           the total CDF.
                       MEMBER KRESS:  Oh, I know.  But maybe
           1.174 says don't use the IPEEEs.  Go back and do a
           real seismic analysis.
                       MEMBER POWERS:  Yes, but we never mean
                       CHAIRMAN APOSTOLAKIS:  But we never mean
                       MEMBER POWERS:  We say total CDF, but we
           never mean that, because we say that there's no risk
           whatsoever due to shutdown events.  And now we're
           saying there's no risk due to seismic events.  And
           pretty soon we'll get around to saying there's no risk
           due to fire events.
                       MEMBER KRESS:  Might as well forget the
           internal events, too, then.
                       MEMBER POWERS:  Might as well leave them
           out as well.
                       MR. LEHNER:  I think some people actually
           have proposed a way of getting a pseudo-CDF, something
           like an analysis.
                       CHAIRMAN APOSTOLAKIS:  But why?  I mean,
           I don't understand it.  How much would it cost? 
           Because remember now, these guys are building on what
           EPRI has done and Lawrence Livermore.  They are not
           starting from scratch.  They are just implementing
                       MR. LEHNER:  And they also have the
           internal events PRA, too.
                       CHAIRMAN APOSTOLAKIS:  And they have the
           internal events PRA.  They have to do walkdowns
           anyway, no matter which approach they take.  So it's
           a mystery to me.  I mean, what -- is it because it
           will take time to try to understand what Livermore
           did?  I don't understand this.
                       VICE CHAIRMAN BONACA:  Well, I think in
           part it's the timeframe when the IPEEE came.
                       CHAIRMAN APOSTOLAKIS:  It was 10 years.
                       VICE CHAIRMAN BONACA:  Well, the utilities
           at that time were not allowed to use PRAs to justify
           changes as we see today, as 1.174 allows.
                       CHAIRMAN APOSTOLAKIS:  That may very well
           be part of it, yes.
                       VICE CHAIRMAN BONACA:  So that shift I
           think would justify on our part now to raise our
           expectations, because since, you know, we have right
           now an STP that is coming, for example, with a
           significant initiative that is based on PRA insights,
           then that should be a counterpart in higher
           expectation.  I don't think we are seeing it, you
           know, here -- because, again, it's the outcome of the
           program that started 10 years ago.  Things have
                       MEMBER POWERS:  I think it's imperative to
           understand that there's been a change in mindset
           between when this Generic Letter was sent out --
                       CHAIRMAN APOSTOLAKIS:  That's right.
                       MEMBER POWERS:  -- and today that's a
           fairly significant change in mindset.  And so those
           people that undertook things promptly after reading
           the letter really had no opportunity to respond to
           that change in mindset.
                       VICE CHAIRMAN BONACA:  But wouldn't it be
           appropriate at this point for us to say they --
                       MEMBER POWERS:  Well, it depends on
           whether they want to go to the risk-informed
           regulations or not.  I mean, those are optional, so
           it's --
                       CHAIRMAN APOSTOLAKIS:  I think we're going
           to end up with a standard thing that is going to say,
           "These analyses will be upgraded as necessary in the
           future."  I don't think anyone will go out and say,
                       MEMBER KRESS:  I think we did exactly the
           same thing in the IPE.
                       CHAIRMAN APOSTOLAKIS:  Yes.  And it's
           happening, by the way.  It is happening.  I mean, they
           are upgrading their IPE.
                       MEMBER POWERS:  Yes.  But the opposite is
           happening, too, George.  People are coming in and
           saying, "Well, from the IPEEEs we get or" --
                       CHAIRMAN APOSTOLAKIS:  And those guys do
           not find the staff very sympathetic, they don't think.
                       MEMBER POWERS:  It's the staff that's
           doing it.
                       CHAIRMAN APOSTOLAKIS:  Then we should not.
                       VICE CHAIRMAN BONACA:  The main concern I
           have is what already Tom voiced on a specific issue. 
           This document will be used in the future to draw a lot
           of conclusions, a lot of --
                       MEMBER POWERS:  I think this document
           could be used to draw a number of conclusions,
           probably none of which are intended by you, the staff,
           or the industry.
                       VICE CHAIRMAN BONACA:  Absolutely.  And
           those conclusions might be, you know, solidly
           incorrect, because it's just so limited.
                       CHAIRMAN APOSTOLAKIS:  But it's really --
           I mean, coming back to the original question, it's --
           I'm a little bit puzzled by this tendency to do
           margins analysis.  I mean, you could call this a
           screening analysis, which is a legitimate part of any
           PRA and then say, "Now, the remaining stuff I'll
                       MEMBER KRESS:  That would be the right way
           to do it.
                       CHAIRMAN APOSTOLAKIS:  That's the right
           way to do it.
                       MR. LEHNER:  You know, I think my -- just
           my own opinion, but I think the fact that, as I
           mentioned earlier, that the A-46 program already
           involved doing a -- basically a margin analysis, it
           was very convenient for licensees to then do a
           similar, somewhat enhanced thing for the IPEEE.
                       VICE CHAIRMAN BONACA:  You know, margins
           analysis was valuable for licensees in the early '80s
           when they were building plants, and they were asked to
           perform PRAs to demonstrate that the plant, as
           designed, had significant margin involved, what was in
           the design, and, therefore, no change had to be made. 
           That was the purpose of, really, margin analysis.
                       For this purpose, I totally agree with you
           that it doesn't give you the insights that you would
           want to have.
                       CHAIRMAN APOSTOLAKIS:  Are you saying that
                       MR. LEHNER:  Well, we mention that --
                       CHAIRMAN APOSTOLAKIS:  I mean, you have a
           Section 264, Seismic Evaluation Methods and Strengths
           and Weaknesses.  Are you saying anywhere that the
           margins analyses are limited and that perhaps in the
           new regulatory environment they will not be too
                       MR. LEHNER:  No.  We don't quite say that,
           no.  I mean, we talk about what a -- you know, what an
           SPRA gives you and what a margin analysis gives you.
                       CHAIRMAN APOSTOLAKIS:  Yes.  But, again,
           you are placing them on the same level.
                       MEMBER SHACK:  When you read what he says
           about the seismic PRAs, it does not inspire a whole
           lot of confidence.
                       CHAIRMAN APOSTOLAKIS:  Like give me a
           characteristic sentence.
                       MEMBER SHACK:  Well, page 254, "In some
           cases, the use of simplified fragilities may have
           obscured findings related to dominant contributors to
           seismic CDF."
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MEMBER SHACK:  You go back to 247. 
           "Because of the correlation between the analyst's
           expertise and quality of the fragility calculations,
           guidelines or criteria may be made so that only
           analysts with sufficient qualifications will perform
           the fragility calculations in future seismic PRAs."
                       You know, some of the fragility analyses
           are good, and some of them aren't so good.  It really
           is not --
                       MR. LEHNER:  Actually, I think that's an
           interesting point, because I think we also mention in
           the report that overall the margin analyses were more
           consistent among each other.  I think it's because --
           and they're more comfortable with calculating --
           making those kinds of calculations.
                       MEMBER POWERS:  Well, you also have a
           guidance on how to do them, whereas there is no
           guidance --
                       MR. LEHNER:  Right.
                       MEMBER POWERS:  -- for how to do a seismic
                       CHAIRMAN APOSTOLAKIS:  No.  But, I mean,
           coming back to Bill's point --
                       MEMBER SHACK:  Well, I mean, one of the
           conclusions I came to was roughly that -- that maybe
           I'm one of these guys doing these conservative
           assessments, because I didn't trust their ability to
           do something as --
                       MEMBER POWERS:  Well, let me dissuade you
           of that, because it turns out that sometimes they
           follow the directions and sometimes they don't.
                       CHAIRMAN APOSTOLAKIS:  Well, I don't think
           the degree of use of expert judgment in the actual PRA
           is that different from the margins.  I mean, I'm sure
           you can repeat the same sentences by changing one or
           two words and make them applicable to do margins
                       MEMBER SHACK:  No.  And perhaps it comes
           back to -- at least it's consistent because there's a
           guidance document that sort of --
                       CHAIRMAN APOSTOLAKIS:  Yes.  But we are --
                       MEMBER SHACK:  That doesn't make it right.
                       CHAIRMAN APOSTOLAKIS:  What you're saying
           is we are producing consistently results we cannot
                       MEMBER POWERS:  Well, I question about the
           consistency, because I come back to this -- in some
           seismic margin analysis submittals licensees did not
           entirely follow the criteria for success path
           development or their submittal did not contain
           sufficient information to permit verification of the
           appropriate application of the criteria.  I mean --
                       MR. RUBIN:  May I make a comment, please?
                       MEMBER POWERS:  -- this seems to be a very
           flexible world we live in here.
                       MR. RUBIN:  Maybe a couple of comments. 
           First of all, the point that was made that the Generic
           Letter came out 10 years ago, way before Reg.
           Guide 1.174, there was -- I don't even know if it was
           an inkling in somebody's eye, but risk-informed
           activities and the use of PRAs.
                       CHAIRMAN APOSTOLAKIS:  In fact, we
           wouldn't even be using the words IPEs and IPEEEs.
                       MR. RUBIN:  Right.  So, I mean, that was
           not the intent of the IPEEE to use it for risk-
           informed activities.  But I certainly agree, if
           someone has done a seismic margins analysis, it is
           going to be difficult to come up with, you know, a
           quantification to use in Reg. Guide 1.174.
                       Some of the comments that you are -- the
           subcommittee is making in terms of sentences seems to
           cast great doubts on the IPEEEs and their success.  I
           think the intent we were trying to put forward in the
           report is that not everybody did an A job on their
                       So we had to put some perspectives in this
           insight report to generalize or sort of characterize
           the flavor of the reviews.  And what I said earlier is
           that you really need to go and look at the plant-
           specific staff evaluation reports and technical
           evaluation reports to see where these sentences apply.
                       I wouldn't broad-brush sentences that --
           that these kinds of statements apply across the board
           to all of the IPEEEs.  But we didn't want to also say
           that everything was so rosy and glory that it was, you
           know, the best thing we could ever imagine for all of
           the plants.
                       So that's -- I think you need to keep that
           in mind in looking at this report.  It may be a hard
           thing to -- to write or to characterize.  But if
           you've got some suggestions, I'd appreciate it. 
           That's I think the help -- if it helps you in looking
           at the report, how we tried to put it together, that's
           just a comment.
                       MEMBER POWERS:  My quotations of the
           language, not meant for criticism of the author's
           language.  I think you guys were refreshingly honest
           in your presentation here.
                       MR. RUBIN:  But I think it is taken a
           little bit out of context also, because you --
                       CHAIRMAN APOSTOLAKIS:  Alan, let me ask
           you another question.
                       MR. RUBIN:  Yes.  Okay.
                       CHAIRMAN APOSTOLAKIS:  Because I realize
           it's difficult to provide perspectives and comment on,
           you know --
                       MR. RUBIN:  Yes.  We're doing -- there are
           69 perspectives in here, which we're not --
                       CHAIRMAN APOSTOLAKIS:  Okay.  But do you
           think that after this program -- your technical
           opinion and that of your group -- after this program,
           is there a unit out there that, in fact, might have a
           vulnerability in the sense that the seismic-induced
           failure would have a frequency of close to 10-4 or
           even greater?  Is there a chance for that after you've
           done all of this?
                       MEMBER SHACK:  Like Haddam Neck.
                       MEMBER POWERS:  There is one.
                       MR. RUBIN:  Haddam Neck is shut down, not
           because of the IPEEEs by the way.
                       CHAIRMAN APOSTOLAKIS:  But something that
           is hidden, that we don't know about.  I mean, the
           level of review, the level of analysis is --
                       MR. RUBIN:  I've been sitting in on all of
           these reviews.  When I see the kinds of discussions,
           series of discussions that have taken place at our
           Senior Review Board meetings to go into these kinds of
           issues -- and, yes, there's a chance that something
           can slip through the cracks.  We're doing a screening
                       But I'd say we're doing a very -- with the
           resources and the time, and there's nothing -- if
           there's a substantial amount of resources for each
           review -- I think we're doing a pretty good job to try
           and -- there's no zero probability, but I feel fairly
           confident that we have asked questions where there
           were lots of problems in initial reviews.
                       You know, if somebody just takes a
           submittal and uses that as the basis for
           characterizing a plant, I think they could be way off
           base without looking at the discussions on the RAIs
           and the responses that are in the staff's technical
           evaluation report.
                       So short response, I'd say the chance is
           low but it's not zero.  But don't ask me to quantify
                       CHAIRMAN APOSTOLAKIS:  Can you give me a
           qualitative description of the margin?
                       MEMBER POWERS:  A margin.
                       MR. RUBIN:  Isn't low good enough?
                       Well, you know, we didn't see the 10-4. 
           Haddam Neck was on the high end.  But we saw close to
           that.  In fires we saw estimates of greater than 10-4. 
           For CDF estimates, in the low 10-4 range.  We didn't,
           you know, consider or call that a vulnerability.  
                       We felt that the licensee had made lots of
           improvements, even in the seismic analysis.  Where
           they did seismic margins, the walkdowns led to lots of
           improvements.  I mean, John hasn't gotten to that yet. 
           But even though they can't quantify their PRA, they
           did make a lot of fixes based on the IPEEE.
                       MEMBER SHACK:  Well, I sort of see it the
           other way.  You know, I looked at the wide range of
           results you got and this sort of -- you know, does
           this sort of tell you that it's -- you know, you can't
           go any further with generic regulations?  
                       Everything is now so plant-specific that
           you almost -- you know, you really do need a
           performance basis.  If you don't like what they have,
           you somehow have to have a way to look at an
           individual plant and tell them, you know, to get their
           CDF number down.
                       MEMBER KRESS:  Did I hear that right?
                       MR. RUBIN:  I won't touch that one.
                       MEMBER KRESS:  From Bill Shack?
                       MEMBER POWERS:  These metallurgists are
           steeped in rigor.  Just wait until we get to 50.46;
           you'll see rigor.
                       MEMBER KRESS:  Okay.
                       MEMBER SHACK:  Well, I didn't say these
           analyses were rigorous.  I just said they show a lot
           of variability.
                       MEMBER POWERS:  I didn't say the analyses
           were rigorous either.  I just said metallurgists are
           steeped in rigor.
                       MR. RUBIN:  Well, I think we do know that
           there is vulnerability among the design, and we expect
           variability among the PRA results.  So that's not a
           surprise.  Doesn't mean you can't, you know, come up
           with generic regulations.  But if you're doing
           something on risk insights, you really better look at
           the individual plant.
                       MEMBER LEITCH:  Well, I'm left with the
           question that although you did not try to validate
           these results, when I look at the figure like that on
           page 232, I see two and a half orders of magnitude
           difference in the CDF results.  
                       And I guess it seems to me that there
           could be at least three possible reasons for that. 
           One is differences in methodology that was used,
           differences perhaps in identification of issues as a
           result of the walkdown, or perhaps just plain errors.
                       And I guess although you didn't really try
           to validate their results, as I understand, would you
           have looked at some of these outliers to see which of
           those might be contributing to these?  In other words,
           are these really plant differences, or is it
           methodology and --
                       MR. LEHNER:  Well, I think it's both.  I
           mean, certainly, you know, plants have been designed
           to different criteria as seismic standards evolved. 
           But methodology also plays a role, and I think one of
           the -- you know, one of the implicit outcomes of this
           whole individual plant examination and risk-informed
           regulation is this idea of adopting standards to try
           and perhaps eliminate some of the variation in the --
           in what's an acceptable methodology.
                       I believe the NS standard on seismic
           analysis is -- either has been released or is about to
           be released.  
                       So in answer to your question, I think
           there is both elements, but I think the recognition
           that methodology played a role has also led to the
           idea of trying to put out some standards that would
           narrow those differences in methodology.
                       VICE CHAIRMAN BONACA:  We just talked
           about Haddam Neck with 2.3 10-4 CDF from seismic. 
           It's not surprising.  But there are now plants of the
           same vintage still in operations, and they chose not
           to perform a PRA.  So you have only a seismic margin
                       You know, there are issues left like that
           that come to mind all the time as I read that.  What
           about that?  Seismic margin seems to say that that's
           okay, and yet some of these plants they are part of
           the same vintage.  Why would they be different from
           Haddam Neck?  They wouldn't.
                       MR. LEHNER:  They wouldn't.  I mean --
           well, I mean, you know, I don't want to categorically
           say that they would have the same core damage
           frequency.  But, yes, I mean, there were plants out
           there even when the margin analysis basically -- I
           mean, there are plants where the margin analysis did
           not give them a large margin over their design basis
           earthquake, as we'll get to later on.
                       So, certainly, plants seem to be up to the
           -- there was no plant that had a HCLPF that was below
           their design basis, but there were certainly plants
           whose HCLPFs were below the review level earthquake.
                       All right.  So just to conclude with this
           slide here, basically two margin analyses, one
           developed by the NRC, which is an event tree/fault
           tree approach, and the other one by EPRI, which is the
           success path approach.  And almost all licensees that
           did a margin analysis used the EPRI method.  I think
           there were only two licensees that did an NRC seismic
                       Now, the guidance in NUREG-1407 basically
           binned the plants into various analyses categories,
           and this was based on the seismic hazard associated
           with a plant site as well as, to some degree, the
           design of the plant.
                       Maybe it's easier to start out with a full
           scope seismic margin analysis where the SSCs will be
           evaluated against a review level earthquake, which was
           basically 0.3 g for the eastern U.S.  These plants had
           to do a detailed relay chatter evaluation, soil
           failure evaluation, and, of course, perform a walkdown
           -- a detailed seismic walkdown.
                       Most of the plants that did -- that were
           binned into the focused scope seismic margin category,
           here again, they had to evaluate their equipment
           against a review level earthquake.  The relay
           evaluation was less rigorous in the sense that only
           relays that had been identified previously under the
           A-46 program as low ruggedness relays that were now in
           the IPEEE scope but not in the A-46 scope had to be
                       And as far as the soil failures, these
           plants originally were asked to do a soil failure
           evaluation under Supplement 4.  And so the ones that
           did their margin analysis early on did so, but most of
           the plants actually did not have to do a soil failure
           evaluation because Supplement 5, which was issued in
           the mid '90s, recognized the lower seismic hazard of
           the revised Livermore studies and eliminated soil
           failure evaluation from the scope of the focused scope
           seismic margin analysis.
                       And then there was also reduced scope
           seismic margin for those plants which were in very low
           hazard areas.  And here the plant basically did not
           have to evaluate against the review level earthquake,
           the 0.3 g earthquake, but basically had to evaluate
           against their design basis, their safe shutdown
           earthquake.  So the safe shutdown earthquake became
           the review level earthquake in that sense.
                       And, of course, the plants in the western
           U.S. either had to do a seismic PRA, or the 1407 also
           let them do a 0.5 g review level earthquake margin
                       CHAIRMAN APOSTOLAKIS:  You said that some
           were EPRI proposed and some NRC.  From these, your
           scope of what -- which one is EPRI?
                       MR. LEHNER:  Either one.  You could use
           either methodology --
                       CHAIRMAN APOSTOLAKIS:  To do any of these.
                       MR. LEHNER:  -- to do any of these.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. LEHNER:  Yes.  As I said, only two
           plants use the NRC margin analysis.  But the scope
           here could be accomplished using either one.
                       This next slide shows how NUREG-1407
           binned the plants and what they actually did.  in
           other words, on the left-hand side here, there were 10
           plants that were binned in the reduced scope category,
           49 in the focused scope, eight in the full scope, and
           four that had to do seismic PRAs.
                       As it turned out, many more plants did
           seismic PRAs.  A lot of the focused scope plants did
           seismic PRAs, so we wound up with a total of 27
           seismic PRAs out of the 71 submittals.  One plant did
           actually both analyses, did both a margin analysis as
           well as a seismic PRA analysis.
                       A number of plants -- as you can see here,
           the shaded area sort of indicates the minimum.  If
           they're in the shaded area they did something less
           than what was specified in 1407, and there were a few
           plants that in the reduced scope category sort of did
           a plant-specific analysis which was a variation on
           reduced scope.  
                       And in the focused scope category there
           were a number of plants that felt that the Supplement
           5 allowed them to actually do a reduced scope.  And in
           those cases while the submittal was, let's say, less
           than adequate to --
                       CHAIRMAN APOSTOLAKIS:  John, let me ask
           you something --
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  -- because I don't
           quite follow.  I look at the last column.
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  SPRA.  And it says
           -- it has four numbers -- 1, 18, 4, and 4.  The total
           is 27.
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  What does that
                       MR. LEHNER:  Okay.  If you look at --
           let's look at the second row, focused scope.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. LEHNER:  Forty-nine plants were binned
           into the focused scope bin in 1407.  So those 49
           plants could have done a focused scope margin analysis
           and satisfied the requirements.  It turns out that, of
           those 49, 29 actually did a focused scope, 18 did a
           PRA, and three did a reduced scope.
                       CHAIRMAN APOSTOLAKIS:  But why, then, did
           they end up in the focused scope bin if they did the
           reduced scope?
                       MR. LEHNER:  Well, that's what I was just
           explaining, that they -- I mean, the bins were set up
           ahead of the IPEEE process.  The bins were the minimum
           requirements the plants had to fulfill in order to
           meet the intent of the IPEEE.  
                       Most plants either chose to fulfill those
           minimum requirements or did more, like those 18 plants
           that did the PRA actually did more than they were
           required.  In a few cases, plants did less than they
           were required, and those are the ones in the shaded
                       CHAIRMAN APOSTOLAKIS:  And they still
           claim they did a focused scope?
                       MR. LEHNER:  Well, they claimed that
           Supplement 5 gave them relief from focused scope and
           they could do a reduced scope, which was a
           questionable interpretation.
                       CHAIRMAN APOSTOLAKIS:  Well, then, how did
           you decide to put a unit in the reduced scope bin or
           the focused scope bin?  That --
                       MR. LEHNER:  Oh.  Because when they
           presented their submittals, their submittals --
                       CHAIRMAN APOSTOLAKIS:  So they declared
                       MR. LEHNER:  They declared themselves.
                       CHAIRMAN APOSTOLAKIS:  Oh, I see.
                       MR. LEHNER:  Yes, they declared
           themselves.  They stated how they met the IPEEE.
                       CHAIRMAN APOSTOLAKIS:  So 49 licensees
           declared they were doing the focused scope.
                       MR. LEHNER:  No.  Forty-nine licensees --
           the guidance by the NRC said you 49 licensees have to
           do at least a focused scope.
                       CHAIRMAN APOSTOLAKIS:  Hmmm?
                       MR. LEHNER:  The left-hand column is the
           guidance by the NRC in NUREG-1407.  It said you 49
           licensees have to do at least --
                       CHAIRMAN APOSTOLAKIS:  So you told them
           what to do.
                       MR. LEHNER:  Yes.
                       MEMBER SHACK:  Set a minimum.
                       MR. LEHNER:  A minimum standard.
                       CHAIRMAN APOSTOLAKIS:  For those 49.
                       MR. LEHNER:  Yes.  That was the minimum
           standard for those 49 plants.
                       CHAIRMAN APOSTOLAKIS:  So you --
                       MEMBER SHACK:  And then you guys went
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  So you told four
           licensees to do a seismic PRA.
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  But, in fact, 27 of
           them did it.
                       MR. LEHNER:  Right.  Exactly.  So, you
           see, it actually is -- it's actually a little bit --
           I mean, if everybody did the minimum you'd only have
           four seismic PRAs out there.
                       CHAIRMAN APOSTOLAKIS:  Anyway, I -- okay. 
           But did you see a clear difference between the
           conclusions and insights that a seismic PRA offered
           versus one that is a reduced scope?  I mean, is it
           clear that the licensee who did the seismic PRA
           benefitted more?
                       MR. LEHNER:  Oh, yes, I think so.  I mean,
           the seismic PRA would give you, you know, dominant
           contributors.  A reduced scope basically -- you know,
           a reduced scope, the licensee did not even have to
           calculate a HCLPF for the plant.  They basically just
           had to see that they met the review level earthquake. 
           And the justification was that these were plants in a
           very low seismic hazard area.
                       CHAIRMAN APOSTOLAKIS:  I'm sorry.  Go
                       MR. LEHNER:  Sure.  I was saying that
           there is definitely, you know, greater benefit to the
           seismic PRA because the PRA gave the licensees better
           insights as to not just the core damage frequency but
           also the dominant contributors during a seismic event
           to core damage, whereas a reduced scope basically only
           told them that their equipment was adequate for the
           design basis earthquake.
                       CHAIRMAN APOSTOLAKIS:  Okay.  You have a
           total of 21 viewgraphs and you are just completing
           number 7, which is one-third.  And you have been
           talking for an hour.
                       MR. LEHNER:  I'll try to speed it up here.
                       All right.  In the seismic area, nobody
           really -- well, I shouldn't say nobody.  The
           vulnerabilities -- it was left to the plant to define
           what constituted a vulnerability, and definitions
           varied quite a bit.  Many plants -- most of them that
           did margin analysis did not define vulnerability but
           said they had none anyway.  And a lot of plants
           avoided the term altogether.  
                       In some cases, in the seismic area where
           they did identify vulnerabilities, the kinds of things
           that they identified were similar to what other plants
           called outliers or open issues or anomalies.  So, you
           know, the bottom line is that the -- where
           vulnerabilities were identified they were -- it would
           be unfair to characterize those plants any differently
           than the ones that did not identify vulnerabilities.
                       Now, by the way, I think one reason that
           no serious vulnerabilities were identified was because
           of the fact of some of these other previous seismic
           programs, like A-46, where a lot of inadequacies have
           been addressed already and fixed.  Be that as it may,
           even though very few licensees identified
           vulnerabilities, almost all licensees made some kind
           of fixes that related to outliers or open issues that
           they identified during their assessment.
                       And so a lot of improvements were made in
           the seismic area in response to their analysis.  And
           this list -- some of those examples, they are
           basically improvements in the hardware area, in
           maintenance, housekeeping issues, or in procedures and
           training.  Overall, 70 percent of the plants made some
           sort of improvements in response to their seismic
                       And you can see here the number of plants
           that reported this type of improvement.  For those
           plants that had no IPEEE-related improvements, about
           half of them had already made improvements under the
           A-46 program and felt there were no further fixes
           needed under IPEEE.  And then, you know, about 10
           plants said that -- mainly the newer plants said that
           there were no additional fixes that they had to make.
                       MEMBER UHRIG:  On the hardware, there were
           sort of three generations of seismic hardware over the
           years.  Was this additional hardware coming in, or was
           it replacement with the more sophisticated hardware?
                       MR. LEHNER:  I think in some cases it was
           replacement.  For instance, in the relay area it made
           some replacements.  But additional -- but mainly it
           was -- as indicated there, you know, strengthening
           anchorages, bolting things down, bolting things
           together, eliminating spatial interaction problems
           where one component -- a non-safety-related component
           could fail and fall onto a safety-related component,
           that sort of thing.
                       So it was not a large exchange of
           equipment.  As a matter of fact, most of these
           improvements were low-cost improvements, you know, in
           spirit with the Generic Letter, really.  They were
           low-cost improvements, but significant improvements,
           effective improvements.
                       MEMBER KRESS:  How did they reinforce
           masonry walls?
                       MR. LEHNER:  How did they reinforce
           masonry walls? 
                       MEMBER POWERS:  Steel and wire.  That's
           the most common way to reinforce it.
                       MEMBER KRESS:  Just build a frame in front
           -- on each side of it?
                       MEMBER POWERS:  All the way around it.
                       MR. LEHNER:  At least to -- yes, to
           prevent it from falling onto -- I mean, the masonry
           walls issue, again, was only an issue if the masonry
           wall would --
                       MEMBER KRESS:  If it falls onto something.
                       MR. LEHNER:  -- fall onto some vital piece
           of equipment.  So if you could protect it --
                       MEMBER KRESS:  I would almost think you'd
           have to have a framework to do it, rather than just --
                       MEMBER POWERS:  Well, usually just some
           bars across it.  Or weaken it on the other side, so it
           would fall in the other direction.
                       MR. LEHNER:  All right.  Let me quickly go
           through these elements that were common to all of the
           seismic IPEEEs.  Screening was done both in the PRA
           area and in the seismic margin area.  
                       The screening level -- for those people
           that did margin analysis, they basically used the
           review level earthquake, g level, as the screening
           level, and used the EPRI NP-6041 guidance.  There are
           tables in there that allow you to screen out
           components based on past experience.
                       In the PRAs, they also screened out in
           some cases based on the review level earthquake; in
           other cases, higher screening levels.  And, in
           general, in many PRAs they screened out the majority
           of components.  Obviously, that would reduce the
           amount of analysis that had to be done.
                       The walkdowns were really I think one of
           the most important benefits of the IPEEE program,
           especially for those plants that did a reduced scope
           analysis.  It was really a walkdown that was the
           essential outcome of the IPEEE, where they looked at
           their SSCs, looked at capacity versus demand, and
           looked for outliers, and quite a few outliers were
                       They checked anchorages, looked at spatial
           interaction concerns, identified those, and there were
           many -- I think most of the insights that the
           licensees gained came out of the walkdown process.
                       I'll talk about the dominant contributors
           and weak links a little later on.  For relay
           evaluation, because the relays had been evaluated so
           thoroughly in the A-46 program, there were a few
           significant low ruggedness relays that were identified
           solely as a result of the IPEEE program.
                       The IPEEE program scope was a little bit
           bigger than the A-46 program, so there were more
           relays included under its scope.  But those relays
           that were identified as low ruggedness usually proved
           to be not important for the safe shutdown of the
                       MEMBER POWERS:  I will say that in the
           documentation on this, where you discussed this is
           extremely confusing.  What you've written up here is
           very clear.
                       MR. LEHNER:  Okay.
                       MEMBER POWERS:  You might want to change
           that language, because it took me forever to sort out
           what you actually meant by the words in here.  That
           sentence is much better than the -- what you say --
           things like chatter or vulnerable relays in selected
           success path circuitry that related only to the IPEEE
           did not have adverse consequences.  And that made no
           sense to me.  If it was a success path, it had to have
           adverse consequences.  Now I think I understand better
           what you were saying.
                       MR. LEHNER:  Yes.  I understand what
           you're saying, but the key phrase there is "related
           only to the IPEEE."
                       MEMBER POWERS:  Yes.  That clause you say
           has already been fixed --
                       MR. LEHNER:  Okay.
                       MEMBER POWERS:  -- is what you need in
                       MR. LEHNER:  Right, right.  Exactly.
                       Soil evaluation -- as I indicated before,
           those sites that were located on -- those plants that
           were located on soil sites did soil analyses for
           liquefaction and slope instability.  They looked at
           stresses in buried piping.  And as we discussed
           earlier, there is no general consensus on the best
           approach to look at liquefaction-induced soil
                       But some sites had identified this as a --
           as -- actually, they identified it in their screening
           analyses -- or I should say in their first analyses,
           those sites that identified soil problems usually went
           back and took a closer look and managed to allay some
           of the concerns with their soil failure.
                       As far as non-seismic failures in human
           actions, in the PRAs these were, of course, included
           in the event trees and fault trees, because most
           licensees that used seismic PRAs adopted their
           internal events -- event trees and fault trees, and so
           they had human actions and non-seismic failures
                       And for the human actions they used a wide
           variety of approaches to account for seismic stress. 
           Usually they had a multiplier on the human failure
           rates that they used in their internal events, and
           then had some g-level beyond which the action was no
           longer considered credible.
                       MEMBER POWERS:  I mean, it seems plausible
           what they did, but how do you -- how do you have any
           confidence that the multiplier or the scaling factor
           that you've used has any bearing on reality?
                       MR. LEHNER:  Well, that's a difficult
           question.  I mean, you know, it's hard to run a
           simulation of a seismic event.
                       MEMBER POWERS:  Well, actually, it's
           probably pretty easy.  We just don't do it.
                       MR. LEHNER:  I think if you get the right
           stress levels, it's --
                       CHAIRMAN APOSTOLAKIS:  That's a very
           important point.  In fact, on page 225, the report
           says that no strong technical basis was provided for
           the values chosen, which is an accurate statement. 
           But what is disturbing a little bit is that it was not
           identified -- this issue of human error probabilities
           was not identified anywhere else in the report as a
           weakness of the methodology and as something that
           something needs to be done about.
                       I think the guys who wrote 264, Seismic
           Evaluation Methods and Strengths and Weaknesses, were
           seismic people.  And they have no appreciation of the
           human error stuff; that's for somebody else.  Yet we
           are talking about seismic PRAs here, so the whole
           thing is one thing.  So to -- and the same thing
           applies to fires, by the way.
                       But to say this -- that somebody says --
           and I multiplied by five because, you know, there were
           bad conditions, and everybody says okay, that doesn't
           make sense to me at all.  And then --
                       MEMBER POWERS:  Well, we accepted an STP
           for doing sensitivity studies.
                       CHAIRMAN APOSTOLAKIS:  That's not the same
                       But then what's even more perplexing is if
           you go to page 529, which deals with -- now you're
           going to tell me somebody else is going to do that,
           but this is for that somebody else -- IPEEE-related
           aspects of common cause failures related to human
                       Okay.  All of the 69 IPEEE submittals,
           which excludes Haddam Neck, provided some treatment or
           discussion of non-seismic failures and human actions. 
           Of the 69 submittals, 61 provided adequate information
           to resolve this issue -- this issue being part of
           Generic Safety Issue 172.
                       Two provided adequate information to
           partially resolve this issue, and six did not provide
           adequate information.  And so what I would like to see
           is the details from one of the 61 submittals that
           provided adequate information using these non-sensical
           multipliers and to resolve a generic safety issue. 
           How can that be?
                       On the one hand, we say that there is no
           strong basis for these numbers.  And then we say 61 of
           69 provided adequate information to resolve this
           issue.  So maybe someone who will address the issue of
           the generic safety issue later will explain this?  I'd
           like to see the details.  I'm not really objecting to
           this.  It's just that it sounds like it's inconsistent
           with the technical evaluation that went on before.
                       And, you know, if you look at -- I guess
           common cause failure and human error, if you look at
           page 525 where there's a figure, it's clear that
           common cause failure is an important element.  So how
           did these 61 guys manage to resolve the generic safety
           issue when the technical basis is not strong?
                       John, you can go on.  Obviously, you're
           not going to -- you are not the one to answer the
                       But I -- you know, this is another case,
           like the one we were discussing earlier regarding
           total CDF.  We say that human error is important; the
           agency should do something about it.  And then people
           do these funny things, and we don't raise hell.  And
           we just accept it, and, you know, well, what can you
           do?  I mean --
                       MR. RUBIN:  Can I --
                       CHAIRMAN APOSTOLAKIS:  Yes.
                       MR. RUBIN:  May I add a couple of points? 
           In many of the seismic submittals in particular, in
           terms of human failure, human actions, the seismic
           event was over quickly, and the procedures that the
           licensees had in place were for operators in the
           control room, for the large part.
                       There were instances -- I can think of an
           example where a licensee was -- and we questioned this
           -- the licensee was going to take credit in a seismic
           fire interaction for going down into the plant and
           shutting a valve for hydrogen in the line for a
           seismic event.  And we said, "Wait a minute.  How can
           they take credit for that?"  And we pursued that
                       But for the large part, many of the
           actions were in the control room.  They're not remote. 
           The seismic event is over relatively quickly.
                       CHAIRMAN APOSTOLAKIS:  But I --
                       MR. RUBIN:  We need to clarify the report,
           I think.
                       CHAIRMAN APOSTOLAKIS:  But I still would
           like to see one or two representative cases from the
           61 licensees.
                       MR. RUBIN:  We'll try to get you some this
                       CHAIRMAN APOSTOLAKIS:  That would be more
           convincing, I think.  That would be an uncertainty
           analysis, sensitivity analysis.  But perhaps the
           people who write the conclusions on seismic and fire
           should not be seismic and fire experts, because they
           have no appreciation for everything else.
                       Okay.  You can't say in one place the
           numbers are arbitrary, and then when it comes to the
           conclusions you don't even mention it.  I mean, I --
           it seems to me based on what I read here, not on what
           Alan said, there is very strong evidence in this
           report that we really don't know how to quantify human
           error -- period -- under these conditions.  And we
           should say that.
                       Now, that doesn't necessarily mean that
           the IPEEEs are useless, because, you know, there may
           be situations like Alan just described one or two
           where, you know, that may not be the driving force. 
           But it should be emphasized, because it -- this -- you
           know, anyway, I said enough.
                       MR. LEHNER:  I think maybe what you're
           saying, it should be one of the items that's mentioned
           under some of the methodological issues.
                       CHAIRMAN APOSTOLAKIS:  Yes.  If some of
           the dominant sequences involve human error, yes, it
           should be.  Even though it is not something that a
           fragility expert will do --
                       MR. LEHNER:  Makes sense, yes.
                       CHAIRMAN APOSTOLAKIS:  -- it's part of the
                       MR. LEHNER:  Well, in the --
                       CHAIRMAN APOSTOLAKIS:  When do you think
           it's a good place to stop?  I don't want you to be
           there for two hours -- if we're going to take a break. 
           I mean, in terms of your presentation.  Don't ask
           other people.
                       MR. LEHNER:  Well, let's see.  Well,
           actually, maybe after these -- maybe after these
           common elements would probably be --
                       CHAIRMAN APOSTOLAKIS:  Okay.  So the next
           one is SPRA results.
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  Okay.  Fine.
                       MR. LEHNER:  Now, just to mention
           regarding non-seismic failures and human actions, in
           the margin assessments, these were usually only
           qualitatively -- well, not usually, they were only
           qualitatively discussed.  And sometimes we had to
           specifically ask in our RAIs about the human actions.
                       And the licensee basically then explained
           that -- about the location and timing of the human
           actions that were involved in the success paths, and
           those explanations were usually convincing that they
           had chosen success paths where human actions were well
           understood and were in the control room.  And so I
           think this reinforces what Alan said earlier.
                       So in that sense, you know, the
           explanations in many cases that they furnished for the
           human actions involved in the success paths were
                       Regarding seismic fire and seismic floods,
           seismic-induced fires were -- the submittals indicated
           that the licensees had looked at seismically-initiated
           fires.  They also looked at seismic actuation of the
           fire suppression system or a degradation of the fire
           suppression system from seismic events.
                       And a number of licensees had found some
           outliers in this area, and they felt that some of
           their significant plant improvements were revealed by
           looking at these issues.  These were things like
           looking at hydrogen lines.  
                       You know, they first looked at fire
           sources and then looked at the vulnerability of those
           sources, like oil tanks or hydrogen lines and how
           vulnerable these were and some of the improvements
           they made was to put added restraints on these things
           and furnish protection from having these items
           initiate fires due to the seismic event.
                       And, again, these came out of the
           walkdowns where, you know, they looked at these plant
           areas where there were fire sources and how vulnerable
           they were, and that was one of the big benefits from
           the walkdowns.
                       There were a few PRAs that actually looked
           at the seismic-induced fires and seismic-induced
           floods in their actual accident sequences, but most of
           them were addressed as minor walkdowns.
                       Regarding containment performance, most of
           the assessments only looked qualitatively at
           containment, looking at containment integrity,
           isolation, bypass.  I mean, the guidance in NUREG-1407
           was that they should look for containment failure
           modes, you know, unique to a seismic event that they
           would -- that would be different from things that they
           identified in the internal events PRA.
                       And there were a few seismic PRAs that
           actually did a Level 2, and, as indicated there, there
           were some -- the LERF frequencies identified in those
           PRAs varied from 10-7 to 1.6 10-5 per year.
                       And, finally, all of the IPEs, as required
           by NUREG-1407, conducted an independent peer review to
           ensure the overall quality of the submittal, and they
           listed the review members.  And some of them even
           listed the questions that the review members had asked
           and their replies to those questions.
                       If there are no questions, I --
                       CHAIRMAN APOSTOLAKIS:  Any questions from
           the members?
                       VICE CHAIRMAN BONACA:  I just had a
           question about seismic fire and seismic flood.  The
           text specifically states that a few of the evaluations
           included those kinds of consequences -- fire and
           flood.  Most of them did not. 
                       MR. LEHNER:  The PRAs.
                       VICE CHAIRMAN BONACA:  Yes, the PRAs. 
           Yes.  In the PRAs that considered those, did they find
           those issues to be significant in risk?
                       MR. LEHNER:  I don't think they showed up
           as dominant contributors.
                       VICE CHAIRMAN BONACA:  Okay.
                       MR. LEHNER:  I do not believe so.  No, I
           don't believe so.
                       VICE CHAIRMAN BONACA:  Okay.  Thank you.
                       MEMBER SHACK:  Typically, who was on these
           independent review -- peer review panels?  I mean,
           other utilities, consultants, internal or --
                       MR. LEHNER:  Usually, there were some
           outside consultants, plus some internal staff members
           who were not involved in the actual IPEEE.
                       MEMBER SHACK:  But in all cases there
           would be somebody from outside, then.
                       MR. LEHNER:  Yes.  Yes.
                       CHAIRMAN APOSTOLAKIS:  Any other comments?
                       Okay.  According to the schedule, we'll
           reconvene at 10:45.
                                   (Whereupon, the proceedings in the
                       foregoing matter went off the record at
                       10:24 a.m. and went back on the record at
                       10:45 a.m.)
                       CHAIRMAN APOSTOLAKIS:  Ready to start
           again, John?
                       MR. LEHNER:  Yes.  Turning now to the
           quantitative results from some of the seismic PRAs
           that were carried out, this viewgraph shows a
           histogram of the various CDFs.
                       Now, as indicated there in the
           parentheses, what's plotted here is the CDF values
           that were obtained with both the EPRI and the
           Livermore hazard data.  In other words, many plants
           appear twice on this histogram.  One was their EPRI
           CDF and one was their CDF based on the Livermore
           hazard data.
                       And, I mean, in general you can see that
           most of the CDFs fall between 10-6 and 10-4, kind of
           the range that previous seismic PRAs have shown. 
           Those three data points in the 10-4 to 10-3 range, two
           of those points are the Haddam Neck plant that, as we
           talked about earlier, has been shut down.  And one of
           them is the Seabrook CDF with the Livermore hazard
           curve.  But with the EPRI hazard curve it's -- the
           Seabrook plant is in the 10-5 range.
                       This next viewgraph just indicates the
           comparison of the CDF based on EPRI versus Livermore
           for those plants that used both hazard analyses.  And
           you can see that the difference, except for that one
           point which happens to be Seabrook where there is an
           order of magnitude difference in their CDF, the --
                       CHAIRMAN APOSTOLAKIS:  I don't understand
           the figure.  Can you make it horizontal?  So what are
           we looking at their?  Seismic CDF-based --
                       MR. LEHNER:  We're plotting here --
                       CHAIRMAN APOSTOLAKIS:  Maybe you can use
           the mobile microphone.
                       MEMBER POWERS:  I mean, you do have it in
           your viewgraph.
                       CHAIRMAN APOSTOLAKIS:  Yes.  But he wants
           to stand up and discuss it.  I mean, if he wants to.
                       MEMBER POWERS:  Well, I mean, it's one CDF
           quantity as to another CDF.  You compute the CDF with
           the one hazard curve, and then you compute it with the
           other, and you plot them one to one.
                       CHAIRMAN APOSTOLAKIS:  I knew there was
           something simple about it.
                       And then the point tells us what?  I mean,
           the 45-degree line, it means that --
                       MR. LEHNER:  Well, if they were exactly
           equal they would all fall on the 45-degree line,
           right?  So this shows you the difference that the
           different hazard curves made.  I mean, if we take any
           one point here, this is the value of the CDF that was
           based on the Livermore curve.  And this is the value
           of the CDF based on the EPRI hazard results.
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MR. LEHNER:  So as I said, if they were
           all -- if the results were all perfectly equal there,
           they would be along this line.  As you can see, this
           is sort of the linear regression line through the
           results that there -- in most cases there was not a
           significant difference.  
                       The one outlier at this point, which is
           the Seabrook -- the one plant here, I mean, here
           Seabrook has a 10-3 -- well, greater than 10-4 CDF
           based on the Livermore curves, but a 10-5 CDF based on
           the EPRI curves.
                       CHAIRMAN APOSTOLAKIS:  So these are based
           on mean curves, right?
                       MR. LEHNER:  These are based on mean
                       CHAIRMAN APOSTOLAKIS:  All of them are on
           the mean curves.
                       MR. LEHNER:  Yes.  Yes.
                       CHAIRMAN APOSTOLAKIS:  So, then, if we use
           uncertainty we might see a greater dispersion.
                       MR. LEHNER:  Certainly, yes.
                       MEMBER POWERS:  What do you mean a greater
                       MR. LEHNER:  I mean, I don't --
                       MEMBER POWERS:  There's no difference.  
                       CHAIRMAN APOSTOLAKIS:  What?
                       MEMBER POWERS:  What you would find is
           there's no difference if you put the uncertainties --
                       CHAIRMAN APOSTOLAKIS:  I don't think so. 
           No difference?
                       MEMBER POWERS:  Yes, you would -- because
           there's uncertainty in the seismic CDF on both the
           horizontal and the vertical axes, the dots would be
           huge and --
                       CHAIRMAN APOSTOLAKIS:  95th percentile for
           Livermore is higher than for EPRI.  So I should see
           some difference.
                       MEMBER POWERS:  It would be
           indistinguishable relative to --
                       CHAIRMAN APOSTOLAKIS:  It depends on what
           I choose to plot.  It depends on what I choose to
                       MR. LEHNER:  Yes.  I was going to say it
           would depend on what you choose to plot.
                       CHAIRMAN APOSTOLAKIS:  Of course it would.
                       MEMBER SHACK:  But is this arising because
           as you go to the lower frequency level the EPRI curve
           is going a little bit -- I mean, you know, you get a
           factor of three at the low --
                       MEMBER POWERS:  I think it's totally a
           statistical sampling.
                       MR. LEHNER:  I mean, there's a comment --
                       MEMBER POWERS:  If you calculated the
           uncertainty in that slope, recognizing the uncertainty
           in the values of the points, I guarantee you you would
           find no way to distinguish that from a 45-degree line.
                       CHAIRMAN APOSTOLAKIS:  So it will be a
           scatter plot.
                       MEMBER SHACK:  So there's a shift in the
           mean curve if you --
                       MEMBER POWERS:  You might -- 
                       MEMBER SHACK:  -- use a lower frequency. 
           That's where --
                       MEMBER POWERS:  Well, I think that's what
           they derive out of it, but I don't think it's a
           meaningful shift.
                       MR. LEHNER:  There's been some speculation
           that the -- even though the curves are different that
           the slopes of the hazard curves in those areas that --
           that control the -- you know, the seismic response are
           not that different.  That's one assumption.
                       MEMBER POWERS:  The other thing I will
           hasten to point out is the regression line is also
           incorrectly calculated, because it assumes that the
           horizontal axis is totally certain.
                       MR. LEHNER:  It's only there as sort of a
           guide to --
                       CHAIRMAN APOSTOLAKIS:  Now, why did, then,
           two of the dots there are below the 45-degree line?
                       MR. LEHNER:  Oh.  That just means that it
           turned out that their EPRI CDF was bigger than their
           Livermore CDF.
                       CHAIRMAN APOSTOLAKIS:  Yes.  The question
           is:  why?
                       MR. LEHNER:  Oh.  Why?
                       MEMBER POWERS:  It can happen in any
           western state in the calculation.
                       CHAIRMAN APOSTOLAKIS:  The widespread
           belief is that if you use the EPRI curves you get
           lower numbers.
                       MEMBER POWERS:  It's eastern seismicity.
                       CHAIRMAN APOSTOLAKIS:  And for the west
           it's the reverse?
                       MEMBER POWERS:  It's not the reverse. 
           They are almost identical.
                       CHAIRMAN APOSTOLAKIS:  So why are both the
           dots below the line, then?  One should be above.
                       MEMBER POWERS:  George, they're below the
           line by the width of a dot.
                       CHAIRMAN APOSTOLAKIS:  So what does that
           tell us, then?  That for the eastern United States
           Livermore is more conservative, right?
                       MR. LEHNER:  Well, I think the -- the
           conclusion that we'd like to draw is that it doesn't
           make much difference which hazard curve you use.
                       CHAIRMAN APOSTOLAKIS:  It doesn't make
           much difference.
                       MR. LEHNER:  As far as your CDF is
           concerned.  And it turned out that it didn't make much
           difference as far as the dominant contributors either.
           In other words, the ranking of the dominant
           contributors didn't change --
                       CHAIRMAN APOSTOLAKIS:  But wait a minute. 
           Why doesn't it make much difference?  Look at the
           points on the left there.
                       MEMBER SHACK:  Yes.  But if you're at
           10-6, do you really care whether you're up or down a
           little bit?
                       MR. LEHNER:  Yes.  I mean, let me -- maybe
           another way to illustrate this --
                       MEMBER SHACK:  Where the action is they
           come together on the 45-degree line.
                       MR. LEHNER:  There's a different way of
           looking at it.  There's a figure out of the text.  I
           mean, this basically compares, you know, Livermore's
           CDF versus EPRI's CDF.
                       CHAIRMAN APOSTOLAKIS:  So this is the
           revised Livermore now, right?
                       MR. LEHNER:  Revised Livermore, yes.  Yes,
           revised Livermore.
                       MEMBER KRESS:  And 14 and 15 are the two
           that are below the --
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  And you're sure
           these are western plants?  14 and 15?
                       MR. LEHNER:  No.  These are -- no, because
           we want some plants who use site-specific spectra.
                       CHAIRMAN APOSTOLAKIS:  Okay.  So it
           happened, then, for the eastern United States, which
           is an eastern -- maybe you have very strong values
           for --
                       MR. LEHNER:  Well, I guess it depends on
           where their seismic response is.  If you'd like I can
           look up what plants those are.
                       MEMBER KRESS:  I was wondering whether it
           had anything to do with the uniform spectrum that --
           which gets kind of -- it gets convoluted with this.
                       MR. LEHNER:  Well, yes.  Pilgrim and
           Oyster Creek.
                       CHAIRMAN APOSTOLAKIS:  Oh, okay.  So they
           are both eastern United States.
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  Maybe the reason
           was that there were -- the analysts.  Using EPRI and
           Livermore doesn't mean that you are using a concrete
           methodology.  I mean, the analyst must play some --
                       MR. LEHNER:  Oh, certainly.  
                       MEMBER KRESS:  You have to have success
           criteria, and you have to have the fragility of these
           things, and look at the response to different spectra. 
           And I don't know.  You know --
                       MR. LEHNER:  Yes.  But, I mean, again --
                       MEMBER KRESS:  -- a lot of reasons you
           could end up --
                       CHAIRMAN APOSTOLAKIS:  What's number nine?
                       MR. LEHNER:  Number nine?
                       MEMBER SHACK:  Seabrook.
                       MR. LEHNER:  That's Seabrook.  Yes, that's
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MEMBER KRESS:  You know, that almost has
           to be in response --
                       MR. LEHNER:  Presumably, the analyst was
           the same for both the EPRI and the Livermore analyses.
                       MR. RUBIN:  John, the high one was Haddam
                       CHAIRMAN APOSTOLAKIS:  Nine was Haddam
                       MR. LEHNER:  No, nine was --
                       MEMBER SHACK:  No, Seabrook.
                       MR. LEHNER:  -- Seabrook.
                       MR. RUBIN:  I think 15 is Haddam Neck. 
           Yes, that's Haddam Neck.  It's the one with the EPRI
           curve.  The EPRI is higher than the Lawrence
                       MR. LEHNER:  Yes, that's right.  The
           highest one is Haddam Neck, but there is two --
                       MEMBER SHACK:  The second one I think is
                       MR. LEHNER:  Yes, 11 and 14 -- 11 and 14
           have the EPRI higher than the Livermore.  Those are
           Pilgrim and Oyster Creek.
                       CHAIRMAN APOSTOLAKIS:  Bob, you have a
                       MEMBER UHRIG:  Well, just point out that
           this is a logarithmic curve.  And take number one
           there, the difference looks very large, but it's
           insignificant compared to something like, say, 13.
                       CHAIRMAN APOSTOLAKIS:  The blue and the
                       MEMBER UHRIG:  Yes.  You have to take that
           logarithmic scale into account when you're looking at
                       CHAIRMAN APOSTOLAKIS:  But also now, since
           you mentioned one, I look at one and I look at 14, 15,
           or maybe nine, or the others, and there is a
           difference in CDF that is two and a half to three
           orders of magnitude.  What are the two driving forces
           behind this?  Why such a wide variability?  Is it the
           design of the plants?
                       MEMBER POWERS:  Where is this two and a
           half orders of magnitude difference?
                       CHAIRMAN APOSTOLAKIS:  Well, it's 10-7 in
           one, two or three 10-7, and then the other one -- 15
           is two or three --
                       MEMBER POWERS:  Oh, you mean across the
                       CHAIRMAN APOSTOLAKIS:  Yes.  Yes.  So what
           is the driver?  Is it the design, or is it the
                       MR. LEHNER:  Well, again, I think --
                       CHAIRMAN APOSTOLAKIS:  Or where they are?
                       MR. LEHNER:  I think it's a combination of
           those things.  I mean, certainly the design and the
           location are going to play some role.  I think these
           are site-specific hazard curves.  But the analysis as
           well is going to -- you know, as we said before, the
           variation in the analysis obviously I think plays a
           role here, too.
                       VICE CHAIRMAN BONACA:  Some of the older
           plants like Haddam Neck had -- inside an auxiliary
           building separated by walls, so there was very little
           hiding certain components from system interactions. 
           And if you do an analysis, very vulnerable to that,
           there isn't much you can do.  And some of the very low
           ones, of course, they were built and designed with
           poor separation and different concrete walls and
           structures that -- big difference comes from that, in
                       MEMBER KRESS:  When they use a seismic
           hazards curve, do they have to estimate a distance
           away from the fault line, to adjust the curve for
                       MR. LEHNER:  Well, I mean, they -- I think
           they make a variety of assumptions to generate this
           family of hazard curves, including, you know,
           distance, attenuation, and then put certain weightings
           and probabilities on that.  And that's why if you want
           to -- if you want to take the uncertainty into
           account, you should really propagate that whole family
           of hazard curves.  But in this case it was a mean
           curve developed from a family of curves.
                       Listed here are the dominant contributors
           that were identified from the seismic PRAs.  The first
           column is the seismic failures, and the second column
           are the random failures, and the third are the
           operator action errors that were identified as
           dominant contributors.
                       So, as you can see, a majority of the most
           frequently observed dominant contributors under the
           seismic failures had to do with electrical systems. 
           You can see also listed here is the surrogate element
           which showed up in a few PRAs as one of the dominant
           contributors.  We're going to talk more about that a
           little later on.
                       Some buildings also -- I mean, some
           structures like block walls and turbine building,
           auxiliary building, also showed up in the dominant
           contributor column under the seismic failures.  
                       In the random failure and operator action
           area, the diesel generator random failure was, again,
           prominent for both BWRs and PWRs.  And the operator
           action errors for PWRs aligning aux feed was an
           operator action error that was high on the list.
                       For the BWRs it was mainly things related
           to power recovery as far as operator errors go that
           were identified as dominant contributors.
                       CHAIRMAN APOSTOLAKIS:  "Random failures"
           means they failed -- it was out of --
                       MR. LEHNER:  Not due to seismic, not due
           to seismic event itself.
                       So summary conclusions from the PRAs -- as
           I noted earlier, the electrical system components were
           the most frequent contributors.  In about half the
           occurrences those were listed as dominant
           contributors.  Building and structural failures were
           significant, and then the rest was made up by
           frontline and support systems and tanks.
                       And in about six to eight percent of the
           major contributors listed, the surrogate element
           played a role.  And the licensees modeled -- usually
           you screened out --
                       MEMBER SHACK:  Well, that's a funny
           number.  Just, you know, it's seven out of 27 PRAs,
           but then you look at the fraction of the whole
           submittals.  Why don't you just look at the fraction
           of the PRAs in which it was the significant element?
                       MR. LEHNER:  Yes.  Yes.  That's true.
                       MEMBER SHACK:  It's a lot more than six
                       MR. LEHNER:  Yes.  Well, wait a minute. 
           No, I'm -- this is where -- no, I think it -- I think
           the six percent is only for the PRAs.  I mean, seven
           out of the --
                       MEMBER SHACK:  Twenty-seven PRAs had it as
           a significant element.
                       MR. LEHNER:  Okay.  I'm sorry.  Yes, I
           guess that's right.  Okay.
                       MEMBER SHACK:  Well, at least that's what
           the report says.
                       MR. LEHNER:  Yes, that's right.  No,
           you're right.  You're right, yes.
                       CHAIRMAN APOSTOLAKIS:  So you did not
           validate the results of the report.  You just --
                       MR. LEHNER:  Actually, you're right.  I
           was confusing it with something else.
                       Regarding a surrogate element -- and we
           can talk about that more later, but I should mention
           here that most plants that use a surrogate element
           used a single surrogate element for all of the
           screened out components.  
                       But there were some that were -- did a
           little bit more discriminating, where they used
           several surrogate elements, like one for the -- all of
           the components in the aux building, another one for
           all of the components in the safe shutdown facility. 
           So that gave you a little bit better insight into
           where the contributors lie.
                       We've already talked about the fact that
           the EPRI and Livermore hazard curves did not
           significantly alter CDF or the dominant contributors. 
           And in general, we make the statement in the report
           that the CDF values did not necessarily trend upward
           with plant age.  
                       And, you know, we mentioned that I think
           with some caveats that one could perhaps interpret
           this as saying that the seismic programs that have
           been implemented have helped to bring down the CDF of
           older plants to a reasonable level.
                       MEMBER POWERS:  One would say that if they
           were at an unreasonable level prior to the imposition
           of the programs.
                       MR. LEHNER:  Yes.
                       MEMBER POWERS:  Do you know that?
                       MR. LEHNER:  We don't know that, no.
                       MEMBER POWERS:  So the alternate
           conclusion is that the programs have been useless.
                       MR. LEHNER:  Well, you could take a
           positive view.
                       MEMBER POWERS:  You may want to look at
           that language in the report, because you do this
           several times --
                       MR. LEHNER:  Yes.
                       MEMBER POWERS:  -- when you're talking
           about the SEP plants versus the more modern plants,
           and you come to the conclusion that -- that activities
           have made things better.  There is -- the alternate
           conclusion is still left open.
                       MR. LEHNER:  Well, I mean, quite frankly,
           we were struggling how to characterize that.  And I'm
           willing to listen to suggestions.
                       MEMBER POWERS:  Okay.
                       MR. LEHNER:  How to best state that.
                       All right.  Turning to the margin
           analysis, this is a histogram of the different HCLPF
           ranges that were found in the margin analysis.  And by
           the way, the only reason there are three figures here
           is just to distinguish the ranges a little bit better. 
           I mean, people only reported HCLPFs to one or two
                       MEMBER SHACK:  What was the cutoff at .3? 
           Why didn't you just let them report what they found?
                       MR. LEHNER:  Well, the screening was done
           at that level.  In other words, the review level
           earthquake was at .3 g, so they screen out anything
           above that.  So it would have taken a lot more effort
           for them to not screen them.  
                       But that's an important point in looking
           at this HCLPF data because, as you said, if they could
           -- if each plant would actually calculate a plant
           HCLPF as high as possible, then you would probably see
           a different trend than you do if you cut it off at the
           .3 level.
                       VICE CHAIRMAN BONACA:  You will probably
           see a lower CDF -- lower CDF for more recent plants,
           maybe more --
                       MR. LEHNER:  A higher HCLPF for more
           recent plants.
                       VICE CHAIRMAN BONACA:  Yes.
                       MR. LEHNER:  Yes.
                       MEMBER POWERS:  Is there a database that
           I can go to that says, "Okay.  Here is the calculated
           HCLPF, and here is the actual performance of the
           device under various seismic loads or system or
                       MR. LEHNER:  Well, I mean, the tables in
           EPRI 60-41 were based on that kind of a --
                       MEMBER POWERS:  Yes.  Okay.  You're right. 
           You're right.
                       MR. LEHNER:  I should also mention that
           the HCLPF values shown here presume that the
           improvements have been made.  I didn't mention this
           when we talked about improvements.  But some of the
           submittals were somewhat ambiguous as to when those
           improvements would be in place.  So the HCLPF values
           reported here are --
                       CHAIRMAN APOSTOLAKIS:  Let me understand
           again what this means.
                       MR. LEHNER:  Okay.
                       CHAIRMAN APOSTOLAKIS:  If I take the
           second column from the right, .25, .299 --
                       MR. LEHNER:  Right.
                       CHAIRMAN APOSTOLAKIS:  -- I guess it's
           your left -- I see that 10 plants do what?  That I
           have high confidence?  What?  What's my confidence,
           99 percent?
                       MR. LEHNER:  No, no.  Well, the HCLPF is
           a 95 percent confidence at a five percent failure
                       CHAIRMAN APOSTOLAKIS:  So I am 95 percent
           confident that the probability of failure of those
           plants --
                       MR. LEHNER:  It's no greater than --
                       CHAIRMAN APOSTOLAKIS:  -- is five percent.
                       MR. LEHNER:  It's no greater than five
                       CHAIRMAN APOSTOLAKIS:  It's no greater
           than five percent.
                       MEMBER KRESS:  If the earthquake g is no
           bigger than that range.
                       CHAIRMAN APOSTOLAKIS:  If the earthquake
           is no bigger, or if they are designed against such an
                       MEMBER KRESS:  Well, acceleration --
                       MR. LEHNER:  It's that seismic demand
           that's being put on the plant.  In other words, if I
           have a g level between -- these plants reported a
           HCLPF that says that an earthquake -- well, let's take
           the easiest case.  The review level earthquake had a
           g level of .3.
                       So those plants that have a HCLPF of .3 or
           greater, they have a 95 percent confidence that their
           success paths will be available to shut the plant down
           safely at --
                       CHAIRMAN APOSTOLAKIS:  Five percent of the
                       MR. LEHNER:  No, 95 percent of the time.
                       MEMBER KRESS:  It's bad to have a low
                       CHAIRMAN APOSTOLAKIS:  So if my -- now,
           review level, you said -- but what does that have to
           do with the actual plant?  The safe shutdown
                       MR. LEHNER:  Well, the review level
           earthquake is higher than the safe shutdown
           earthquake.  That's the whole idea of the IPEEE.  In
           other words, the safe shutdown earthquake is a design
           basis earthquake.  That's what the plants were
           designed to.
                       So the review level earthquake was chosen
           to see how much margin these plants have above their
           design basis.
                       CHAIRMAN APOSTOLAKIS:  It doesn't tell me
           that.  If my SSE is .2, how does that affect these
           figures?  My SSE is .2.
                       MR. LEHNER:  Well --
                       CHAIRMAN APOSTOLAKIS:  And I do a HCLPF
           analysis with -- do I need the review level earthquake
           for a HCLPF analysis?
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  Okay.  So I do it
           for .3.
                       MR. LEHNER:  Yes.
                       CHAIRMAN APOSTOLAKIS:  So what does that
           tell me?
                       MR. LEHNER:  Well, it tells you what -- if
           your HCLPF is .3, then you have a high confidence that
           your plant will survive an earthquake that's, you
           know, 50 percent higher than your safe shutdown
           earthquake, if you have a safe shutdown.
                       CHAIRMAN APOSTOLAKIS:  I don't know how
           much margin I have.  I just --
                       MEMBER SHACK:  It's your next plot.
                       MR. LEHNER:  Yes.  I was going to say,
           let's go to the next plot.  I mean, this basically
           shows you -- this plots the ratio of the plant HCLPF
           to the SSE value versus the SSE g level.  
                       And the dashed line is -- you know, is at
           one.  In other words, those plants have a HCLPF that's
           just equal to their safe shutdown earthquake.  And
           both of those plants are -- I mean, in some cases,
           these are plants that did reduced scope analyses.  And
           in some cases they did not report a HCLPF, so by
           default we just gave them a HCLPF that was equal to
           their safe shutdown earthquake.
                       The solid line is the highest HCLPF that
           the plant could report because of what we talked about
           a little while ago about the fact that the screening
           level was at .3 g.  So a plant can't report a HCLPF
           above .3 g, because they've screened out the
           components at the 3 g level, so they never evaluated
           those components.
                       So you have to assume a .3 g limit.  But
           this shows you the margins, basically, that the plants
           have above the safe shutdown earthquake based on this
           HCLPF calculation.
                       CHAIRMAN APOSTOLAKIS:  So give us an
           example.  Pick one.
                       MR. LEHNER:  Well, I mean, if we -- if we
           pick this plant here, it basically says that its HCLPF
           value is twice the value of the safe shutdown of --
           the design basis of the safe shutdown earthquake.
                       CHAIRMAN APOSTOLAKIS:  That still doesn't
           tell me what the probability of failure is, though. 
           It just tells me that the HCLPF value is --
                       MR. LEHNER:  It doesn't -- well, I mean,
           it says you have a high --
                       CHAIRMAN APOSTOLAKIS:  In terms of g, in
           other words.
                       MR. LEHNER:  Yes.  I mean, you have the
           high confidence --
                       CHAIRMAN APOSTOLAKIS:  I do, because I
           already have high confidence for the review level.  So
           if you were down --
                       MR. LEHNER:  Well, but this shows you
           that, yes, you have --
                       CHAIRMAN APOSTOLAKIS:  I don't multiply --
           I don't divide the probability by two.  Okay?  I mean,
           I just -- I can only say that I have high confidence.
                       MR. LEHNER:  Yes.  I mean, you can't get
           a quantitative -- yes.
                       CHAIRMAN APOSTOLAKIS:  How much I have I
           don't know.
                       MR. LEHNER:  Right.  That's right.  I
           mean, it does not tell you a -- it doesn't give you a
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MR. LEHNER:  The other issue on this plot
           is that we distinguish between plants who, in their
           analysis, use a new structural analysis or plants that
           simply scaled up their analysis from their SSE,
           because when plants use a new structural analysis they
           -- by eliminating many of the conservatisms that they
           used when they did the original design basis
           calculations, the actually reduced their seismic
                       And, therefore, the HCLPFs that they
           calculated would have been -- were different or higher
           than if they had used a more conservative method.  So
           one has to distinguish between how to calculate it --
           that HCLPF, and that's why you've got the triangles --
           the solid triangles and the open squares.
                       Now, this is a list of the weak links that
           were the outliers that were found in the SMA.  So this
           is not necessarily -- I mean, one can assume, as one
           does with a PRA, that these are the dominant
                       But, nevertheless, these are the -- in the
           success path, when they calculated the capacities of
           their SSCs and the success paths, these were the --
           those SSCs and the success paths that had the lowest
           capacity -- in other words, were the weak links in the
                       CHAIRMAN APOSTOLAKIS:  And the licensees
           did something about it?
                       MR. LEHNER:  Well, I mean, they -- in some
           cases they did, and in some cases they didn't.  I
           mean, the -- getting a plant HCLPF that was lower than
           the review level earthquake was not a problem as far
           as the IPEEE guidance was.  In other words, it was an
           assessment of the plant's capacity.  It does not mean
           that every plant had to have a plant HCLPF above the
           -- equal to or above the review level earthquake.
                       Certainly, if the HCLPF was below the
           design basis, then the plants would fix things so that
           their HCLPF at least came up to the design basis.  But
           there were plants that have HCLPF values that were
           below the review level earthquake value.
                       CHAIRMAN APOSTOLAKIS:  So that did
           something about it.  I mean, the numbers that you have
           shown us so far reflect those changes.
                       MR. LEHNER:  Yes.  Yes.  These numbers
           reflect those changes, and, as a matter of fact, as I
           said, the -- in some cases, the analysis was done by
           the plants before they had actually implemented those
           changes.  So, you know, one of the follow-ups here
           would be to make sure that those changes were actually
                       MEMBER LEITCH:  This does not list
           directly loss of offsite power.
                       MR. LEHNER:  Well, in the margin analysis,
           loss of offsite power was assumed as being
           unrecoverable.  So they -- that was part of the
           guideline of the margin analysis.  They basically --
           in a seismic margin analysis, you assume that you lost
           offsite power and you are not going to recover it.
                       CHAIRMAN APOSTOLAKIS:  I wonder about --
           are they concerned at all about the human performance
           to the margins calculations?
                       MR. LEHNER:  Yes.  They -- the success
           paths that the licensees chose -- the guidance was
           that they should choose success paths that did not
           require, you know, extraordinary human performance,
           and that the -- the actions that would be required
           would be reasonable to carry out under seismic
                       And as I mentioned before, the margin
           analysis talked about this to some degree.  In many
           cases, they elaborated on it when we -- we asked them
           RAIs in this area, because this was an area that often
           was not discussed thoroughly in the submittals.
                       But in responses to RAIs, they talked
           about the timing and location of these actions, and
           provided some justification why these actions were
           feasible under the conditions that they were taking
           place.  But that was the way they addressed the
                       I mean, generally, you can see that the
           weak links that are listed here are similar to the
           dominant contributors that were identified in the
           seismic PRAs.
                       Now, I should also mention here -- we
           talked earlier about a statement in the report that
           talked about the success path, the way they were
           developed in the margin analysis, and that some
           licensees did not completely follow the guidance
           provided in EPRI 60-41.  And that refers mainly to the
           fact that the success paths were supposed to be as
           independent as possible, and some licensees described
           success paths that used the same equipment for some of
           the functions.  
                       Basically, the success paths had to
           identify ways of controlling reactor reactivity,
           reactor pressure, reactor inventory, and decay heat
           removal.  And in some cases plants identified, as
           redundant success paths, let's say, two different
           trains of the same system.
                       So the diversity that you wanted was not
           necessarily there.  And the reasons for this in some
           plants was simply because they didn't have seismically
           qualified equipment to give you the diverse paths.  In
           other cases, it seemed to be a -- well, there was
           perhaps a reluctance to go and do further analysis to
           establish a completely different success path, if
           you've had some seismically qualified equipment that
           could accomplish the safe shutdown.
                       MEMBER LEITCH:  In considering the time
           for operator actions, do you know if they considered
           time for diagnosis?  It's not always apparent that
           you've had a seismic event.  I was telling some of the
           guys at the break that I was in charge of a plant that
           was in a fairly industrial area -- a fossil plant --
           and we had an earthquake.  And it must have -- I was
           at home asleep at the time, and it woke me up and I
           called the plant.
                       It must have taken us half an hour before
           we figured out that we had an earthquake.  I mean, we
           were, first of all, looking around for what might have
           exploded in the plant -- you know, things like aux
           boilers, generators, thinking a hydrogen explosion. 
           Then we thought about, you know, some of the adjacent
           refineries, did they have some kind of a problem or --
                       MR. LEHNER:  Yes.
                       MEMBER LEITCH:  You know, it took a little
           while to say, "I don't know what else it was.  It must
           have been an earthquake."  You know, but it took a
           while to reach that conclusion.
                       MR. LEHNER:  Well, I mean, the -- you
           know, the need here is not necessarily to realize
           you've got an earthquake, but to -- to respond to
           whatever the problem in the plant is as far as getting
           your safety systems in place.  
                       But to answer your question, I think the
           people that did PRAs usually adopted the human error
           methodology that they used in the internal events. 
           And then, depending on the methodology they used, you
           know, there was a diagnostic component.  And then, for
           their external events, they -- as we discussed
           earlier, simply put multipliers on some of those
           failure rates.
                       The margin analyses talked about time
           available to do the action.  They did not necessarily
           talk about the different phases of the action, but
           they certainly talked about the fact that they would
           not credit actions that had to be done very quickly
           under -- where you had to realize very quickly what
           was wrong and take actions very quickly.  So they did,
           in general, use actions that you would have a lot of
           time to implement.
                       MEMBER POWERS:  I'm wondering with
           symptoms-based procedures why the multiplier is
           different from one. 
                       CHAIRMAN APOSTOLAKIS:  In what?  Systems-
           based procedures?
                       MEMBER POWERS:  Symptom-based.
                       CHAIRMAN APOSTOLAKIS:  Oh, symptom. 
                       MEMBER POWERS:  In symptom-based
           procedures, why is the multiplier different than one?
                       MR. LEHNER:  The control room ceiling is
           falling down here.
                       MEMBER POWERS:  Those are one-time events
           and it's over with.  I went through the San Fernando
           Valley earthquake, and we had to respond to chemical
           problems.  And I don't think our response was any
           different than if we would have done anything else.
                       MEMBER KRESS:  Could it be, Dana, that
           when you have an earthquake that you actually invoke
           multiple sequences at the same time?
                       MEMBER POWERS:  Well, if that's the
           case --
                       MEMBER KRESS:  And the symptoms are
           confusing, then.
                       MEMBER POWERS:  Well, I mean, if you have
           a multiple -- if you have multiple events going on in
           a control room at a time, when you do the human
           reliability analysis you take that sort of thing into
           account -- or should.  And maybe -- or maybe it's just
           more ordinary -- that's more ordinary in an earthquake
           event.  I don't know.
                       MEMBER KRESS:  Yes, that would have been
           my guess.
                       MEMBER POWERS:  The fraction level was
                       CHAIRMAN APOSTOLAKIS:  The story Graham
           tells is that they may not even realize it's an
                       MEMBER KRESS:  Well, I sort of liked your
           thing, too.  You don't care.  You just look at what is
           going on in the plant, and that's what the symptoms-
           based do.  But I suspect if the earthquake is big
           enough to give you substantial contribution to the
           CDF, you probably have a lot of things going on, and
           that's where the operator confusion might go in, and
           induced LOCA and induced loss of offsite power at the
           same time, that sort of thing -- going on
           simultaneously it seems to me like.
                       MR. LEHNER:  I think the multiplier
           perhaps is a crude way of compensating for that sort
           of --
                       MEMBER KRESS:  Yes.
                       CHAIRMAN APOSTOLAKIS:  It multiplies a
           number that's --
                       MEMBER KRESS:  It's crude.  If you
           multiply a crude number by a crude number, you get a
           really crude number.
                       MEMBER POWERS:  Well, I'm still perplexed
           how they picked the multiplier.
                       CHAIRMAN APOSTOLAKIS:  It's an engineering
                       MEMBER KRESS:  Yes, that's perplexing.
                       MEMBER POWERS:  I don't even know how they
           have any judgment in this matter.  Probably it's one
           of those things that I can undoubtedly derive from the
           superior work being done at the Haldrin program.
                       MEMBER KRESS:  I'll tell you how it's
           derived.  You know it's bigger than one.  Ten is too
           big.  So what do you do?  You choose five.
                       CHAIRMAN APOSTOLAKIS:  Actually, in Japan
           I believe they did experiments where they put the --
                       MEMBER POWERS:  I mean, that's not --
                       CHAIRMAN APOSTOLAKIS:  But I don't know
           what that means.  I mean, this is almost like what is
           indicated -- proposed about the gas reactor.
                       MEMBER POWERS:  I mean, if you're going to
           -- you have to remind yourself that an earthquake
           occurs, and it's usually a substantial amount of time
           -- hours -- before the next aftershock comes.  Okay? 
           During that period, my experience with the earthquake,
           actually things are kind of quiet and calm, because,
           you know, traffic and what-not.
                       MEMBER KRESS:  Best time of the day, isn't
                       MEMBER POWERS:  All the fans --
                       -- and things like that.  All you hear is
           the blowing of the wind through the broken-out
                       MR. LEHNER:  So turning to some insights
           on the margin analyses, again, the electrical system
           components were often the governing outliers. 
           Building and structural failures, especially block
           walls, were significant as far as weak links go.  And
           then balance of the weak links went along the
           frontline support systems.
                       As that figure previously showed, the
           seismic margins in terms of the HCLPF being above the
           design basis earthquake do vary significantly among
           the plants.  And similar to the PRAs there was no
           observable correlation between the HCLPF values that
           were calculated for the plant and the plant age. 
                       But, again, as we talked earlier, that
           statement has to be qualified with the fact that you
           couldn't calculate HCLPFs higher than .3 g based on
           the screening methodologies used.
                       And, finally, it's important to note that
           with the improvements taken into account there were no
           plants that had HCLPF values below their safe shutdown
           earthquake value.
                       MEMBER KRESS:  Okay.  Is that true for the
           plant on your slide four slides back that had a HCLPF
           value in the range of .1 to .15?
                       MR. LEHNER:  Yes.  Matter of fact --
                       MEMBER KRESS:  That was this safe
                       MR. LEHNER:  That plant -- as a matter of
           fact, I believe that's Quad Cities.  That plant
           originally had a HCLPF of .09, but they committed to
           making some improvements that got it into their view
                       MEMBER UHRIG:  One question on the
           electrical system components here.  Was this mostly
           failure of the components?  Was this the wires being
                       MR. LEHNER:  Well, some of it was relay
                       MEMBER UHRIG:  Relay chatter.
                       MR. LEHNER:  Yes.  But some of it was, you
           know, diesel generator.
                       MEMBER POWERS:  I thought you told us that
           was all fixed.
                       MR. LEHNER:  Well, but some of the weak
           links were still those relays.
                       MEMBER POWERS:  This will all be solved
           when we go to digital systems, by the way.
                       MR. LEHNER:  All right.  The
           methodological issues -- I think we talked about most
           of these, actually all of these I guess.  We've talked
           about the fact -- you know, from hazardous spectrum,
           some of the comments in the reports state that there
           -- it's uncharacteristic as compared to conventional
           spectrum shapes, and use led to a reduction in seismic
                       Use of surrogate elements -- in general,
           this would not be a problem if it was used properly;
           that is, if the screening level was set high enough so
           that the element would not show up as a dominant
                       And by the way I should mention here that
           there were some plants that simply threw away their
           screened out components.  I mean, they did not even
           include them in a surrogate element.  So at least the
           ones that used surrogate elements have knowledge that
           there could be a contribution from those components.
                       We talked about the new SSI calculations
           versus scaling, and how the HCLPFs that were obtained
           should not be compared directly but should be compared
           with each other but not -- not necessarily across. 
           And we also talked about the fact that the component
           fragility calculations varied in quality due to the --
           some of the estimates on the uncertainty and other
           things that went into those calculations.
                       MEMBER KRESS:  Would you elaborate a
           little more on your second bullet?  Why is that a
           problem?  It's a dominant risk contributor.  Because
           it may be overestimating the risk?
                       MR. LEHNER:  No, because you don't -- I
           mean, the surrogate element lumps all of the things
           you screen out together.
                       MEMBER KRESS:  Yes.
                       MR. LEHNER:  So if the surrogate element
           shows up as a contributor, you don't know --
                       MEMBER KRESS:  You don't know whether it
           was or not.
                       MR. LEHNER:  -- well, which of those
           things that you screened out.
                       CHAIRMAN APOSTOLAKIS:  But it warns you to
           go back and look, right?
                       MR. LEHNER:  Well, that's true, yes.
                       CHAIRMAN APOSTOLAKIS:  I mean, that's the
           purpose of it.
                       MR. LEHNER:  Absolutely.  But what that
           would mean is you would have to look at -- you would
           have to set your -- yes, it was not --
                       VICE CHAIRMAN BONACA:  So you have a
           surrogate element that is dominant, and you're saying,
           wait a minute, what's here?  And then you -- so what
           do you do?  You seismically qualify it.  I mean, it
           leaves you hanging there.
                       MR. LEHNER:  I mean, I suppose what you do
           is raise your screening level and --
                       CHAIRMAN APOSTOLAKIS:  Absolutely.
                       MR. LEHNER:  -- screen in more components
           and --
                       MEMBER SHACK:  Right.  Well, again, if
           your risk is 10-6 --
                       MR. LEHNER:  Right.
                       MEMBER SHACK:  -- you know, there's the
           dominant element.
                       MR. LEHNER:  Yes, you're absolutely right. 
                       MEMBER POWERS:  Unless it's a
           metallurgical issue, in which case you can --
                       MEMBER KRESS:  But if you have a large
           number of components that might fail simultaneously
           due to something like the seismic, or might have a
           decreased reliability all because of some common
           reason, would that be a good way to determine an
           importance measure like Fussell-Vesely or Rowell, if
           you just used surrogate elements instead of trying to
           do it for each individual one?  Is that a legitimate
           way to get an importance measure for those things?
                       MR. LEHNER:  No.
                       MEMBER KRESS:  This is another issue is
           the reason I'm bringing it up.
                       MR. LEHNER:  No, I don't think so.  I
           mean, I'm not sure I follow you completely, but I --
                       MEMBER KRESS:  I mean, it seems to me like
           it gets the -- it adds up the importance of all of the
           things you lumped into that surrogate and --
                       MEMBER POWERS:  Does it add them up, or
           does it take the geometric mean?
                       MEMBER KRESS:  Well, that's what I'm
           trying to get at.  I think it maybe takes the mean, so
           it doesn't really add them up.
                       MEMBER POWERS:  I mean, it's equivalent to
           adding it up -- one of them is very important, and the
           others are kind of in the -- I mean, that's the
                       MEMBER KRESS:  I think you're probably
                       CHAIRMAN APOSTOLAKIS:  I think it's an
                       MEMBER KRESS:  Yes.
                       CHAIRMAN APOSTOLAKIS:  It's an
           overestimate.  So human error should be --
                       MR. LEHNER:  Yes, should be one of those
           things mentioned.
                       MEMBER POWERS:  Let me ask a question.  In
           the final analyses of these we saw quite a range of
           assessments on the probability of bypass events being
           created by seismic events.  Within the PWR subset of
           those things, when they analyze things like steam
           generator tube behavior under accidents, did they
           analyze the as-constructed tube behavior, or did they
           look at the degraded tube behavior?
                       MR. LEHNER:  I don't believe that they
           looked at degraded tube behavior.  As a matter of
           fact, let me ask Jimmy if he recollects.  Did anybody
           mention --
                       MR. XU:  No.  No.
                       MR. LEHNER:  I don't think anybody looked
           at degraded.
                       MEMBER POWERS:  So this pain that shows up
           in this document to the -- how useful the walkdown was
           to find the as-built/as-operated plant may apply in a
           lot of areas, but it certainly doesn't apply to steam
           generator tubes.
                       MR. LEHNER:  I would agree.
                       MEMBER KRESS:  It's kind of interesting
           because you would expect they know pretty much how
           degraded their steam generator is.
                       MEMBER POWERS:  Yes.  I mean, one of the
           advantages of the current condition monitoring program
           is you have a pretty good idea what your degradation
           is.  What they don't have I think is they don't have
           a clue how shaking around of the support plates and
           what not would affect things.  I mean, all they know
           is piston behavior.  
                       That would be a difficult calculation to
           do, but it probably casts real doubt on the bypass
           fractions, which are spread.  But I don't believe any
           of them.
                       And bypass, by the way, is not a trivial
           consideration here.  Bypass accidents are consequence-
           producing things.
                       MR. LEHNER:  All right.  Coming up to the
           last slide, here are the conclusions that are stated
           in the report.  Well, no vulnerabilities were
           identified by most plants.  There were significant
           improvements made based on outliers and anomalies that
           the analyses identified.  The analyses basically took
           account of these improvements.  Seventy percent of the
           plants proposed improvements of one sort or another,
           and based on their seismic analysis.
                       The walkdowns, as we talked about, were
           probably a very important part of the IPEEE, with the
           most important part for those plants that only did
           reduced scope evaluations, and many of the
           improvements were carried out based on those
                       The margin analyses and the PRAs seem to
           point to similar components as dominant contributors
           in the PRAs as well as weak links in the margin
           analysis.  Based on these analyses, the age of the
           plant was not, in general, found to be a major factor
           as far as the seismic risk.  And the submittals
           indicated -- the submittals in the RAI responses, I
           should say, indicated that the IPE program was
           successful in meeting the general intent of Generic
           Letter 88-20, Supplement 4.
                       And the licensees did carry out a lot of
           modifications that reduced their seismic risk, but it
           should also be stated that the -- the way it's stated
           here -- the success of the licensees varied, depending
           on the methods and assumptions used.  I think it's
           fair to say that while everyone met the intent of the
           Generic Letter, some licensees made a larger effort
           than others and probably got greater benefits than
           others from this.
                       MEMBER UHRIG:  I find that one statement
           a little puzzling.  The seismic risk in the older
           plants was comparable to the newer.  And yet, when you
           look at the seismic strengths, they went from very
           simple things with an order of $100 per unit to the
           next generation it was $1,000 per unit, and the
           following generation it was $10,000.  Very
           sophisticated seismic constraints.  This implies that
           was a waste of money.
                       MR. LEHNER:  Yes.  I think one -- I mean,
           one point, again, to make is that probably if you
           evaluated the HCLPFs, the plant HCLPF without having
           this .3 g cutoff, we would find that the newer plants
           would have substantially higher HCLPFs than some of
           the older plants.  That's my guess.
                       Any other questions?
                       CHAIRMAN APOSTOLAKIS:  Any other comments
           from the members?  No?  
                       Thank you very much, John.
                       MR. LEHNER:  Thank you.
                       CHAIRMAN APOSTOLAKIS:  I suppose we can
           start with the fires now.  We have to go until 12:30.
                       MEMBER POWERS:  I will acknowledge to
           members that I sometimes hang out with the speaker. 
           At least I know what he is.
                       But I will also point out that during the
           course of him doing this study he absolutely would not
           let me even see a hint of the thing.  He jealously
           guarded it as though it were actually a precious
           commodity.  I shall not forgive him for his
                       CHAIRMAN APOSTOLAKIS:  If you cannot
           forgive, you cannot review.
                       MEMBER POWERS:  What?
                       CHAIRMAN APOSTOLAKIS:  If you cannot
           forgive, you cannot review.
                       MR. NOWLEN:  You'll have to recuse
           yourself for having a grudge against me.
                       MEMBER POWERS:  No.  I just intend to get
                       MR. NOWLEN:  If you would prefer, we can
           defer this.  But --
                       MEMBER POWERS:  Were you talking about
           deferring it until next week or --
                       MR. NOWLEN:  Until after lunch.
                       MEMBER POWERS:  Oh.  George, you know, if
           you want to get started, we'll get started.  If you
           want to defer this until after lunch, we can.  But
           that's entirely your choice here.
                       CHAIRMAN APOSTOLAKIS:  Why don't we start
           and go for about half an hour.
                       MR. NOWLEN:  Okay.
                       CHAIRMAN APOSTOLAKIS:  You've got some
           introductory stuff to show us?
                       MR. NOWLEN:  Sure.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. NOWLEN:  Of course.  Okay.  Well, my
           name is Steve Nowlen.  I'm with Sandia National
           Laboratories.  My role in the IPEEE process was
           primarily as a member of the Senior Review Board.  So
           at that level, I participated in virtually all of the
                       There were a couple of the very early ones
           that I wasn't involved with, but after the first
           couple I did get involved, so I was involved at some
           level in virtually all of these.  And I also led the
           Sandia team that developed the insights report that
           we're talking about today.  It was a team effort, and
           I'll acknowledge my team members as key contributors
           as well.
                       The outline that I'm going to follow is
           quite similar to the other portions of the
           presentation.  I'll give you some introductory
           material.  I'm talk about the vulnerabilities that
           came out of the IPEEE process.  I'll talk about plant
           improvements, CDF perspectives.  
                       We'll do some discussion of where the
           dominant contributors came from based on the IPEEEs. 
           Some discussion of methods and modeling perspectives. 
           There is a lot of material in the report on methods
           and modeling.  We can't go into all of it, so we'll
           cover some of that, and then I'll cover some
                       Okay.  In the way of an introduction, one
           thing to recognize is that all of the IPEEE submittals
           did include an assessment of the internal plant fire
                       And all of the licensees chose some form
           of a probabilistic method to assess fire, but also
           recognize that their submittals vary almost as much as
           the plants themselves vary.  I mean, there was a wide
           range of choices made in both general and specific
           methodologies, so it -- comparing one to another can
           be problematic in that regard.
                       In general, you can categorize the methods
           used in three ways.  There were those licensees who
           relied almost entirely on FIVE.  And FIVE is --
           essentially stops at the level of a quantitative
           screening analysis.  So you get qualitative and
           quantitative screening.  And if you stop FIVE that's
           basically where you stop.
                       Most licensees chose to go beyond that.
           Almost all of the licensees used FIVE to some extent,
           but most of them chose to go on, and they typically
           quantified the contributions from the unscreened
           scenarios.  So they would not stop simply at
           screening; they would continue on.
                       And so you got into various forms of PRA,
           and some of these were new PRA studies, some of them
           were updates of old PRA studies, and then there were
           a couple of plants that actually used a fire event
           tree approach, which was an update of very early risk
           studies that were done.  And so they were a little bit
           unique.  But, again, it was a probabilistic method,
           albeit a very early probabilistic method.
                       MEMBER POWERS:  Where within this spectrum
           lies what is referred to in the report as F PRA IG?
                       MR. NOWLEN:  The fire PRA implementation
           guide would be two types.  There were some utilities
           who began with the FIVE methodology and then did their
           PRA quantifications using the fire PRA implementation
           guide.  There were also a small number of licensees
           who jumped straight into PRA based on the fire PRA
           implementation guide.
                       So they would fall under the second group,
           the various forms of PRA.  That's one of those various
           forms, or actually two of those various forms.
                       CHAIRMAN APOSTOLAKIS:  When you say
           updates of early analyses, what are these earlier
                       MR. NOWLEN:  Well, a lot of plants already
           had preexisting PRAs.  For example, the NUREG-1150
           plants had preexisting PRAs that were out there.  And
           so rather than starting from scratch, they began with
           that and updated it and submitted that as their IPEEE.
                       CHAIRMAN APOSTOLAKIS:  So these were fire
           PRAs, then.
                       MR. NOWLEN:  Yes.  Yes, in most cases.
                       CHAIRMAN APOSTOLAKIS:  Because you make a
           distinction there.  You say fire event tree approach.
                       MR. NOWLEN:  Yes, the fire -- well, the
           fire event tree approach goes back to a very early
           report published by an unnamed laboratory -- Sandia,
           of course -- 1978.  It was a methodology that was
           published before the work at UCLA really hit the
           streets -- very, very early event tree type approach,
           more subjective.
                       CHAIRMAN APOSTOLAKIS:  So some licensees
           use that?
                       MR. NOWLEN:  Yes.  Two plants.
                       MEMBER POWERS:  Those with good taste.
                       MR. NOWLEN:  Well, I'll not comment yet.
                       There were two plants in particular that
           had done preexisting risk studies using that method,
           and so for their IPEEEs they chose to update those
           preexisting analyses rather than start from scratch
           with a new analysis.  And so they followed the same
           approach, updated the results, and submitted that as
           their IPEEE.  But it's not the quantitative PRA that
           you're familiar with.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. NOWLEN:  It's a different one.
                       When it comes to vulnerabilities, the
           situation is, again, similar to seismic.  There wasn't
           a specific definition of what constitutes a
           vulnerability provided by the NRC, so the licensees
           came up with their own definitions.  In some cases
           there was no explicit definition provided.  
                       For those who did provide explicit
           definitions there was a range of criteria applied. 
           These are more or less in the commonality, listed in
           the frequency with which people used a particular
           definition.  The NEI severe accident closure
           guidelines, for example, were the most commonly
                       And then there are a variety of other
           criteria that people used in order to define what
           constituted a vulnerability.  Some -- the most recent
           was singles.  As long as I didn't have any areas that
           led directly to core damage, I didn't have a
           vulnerability, and that was -- a couple of plants use
           that kind of a definition.
                       So when you look at what we got out of the
           studies in terms of identifying vulnerabilities, we
           did, in fact, have two cases.  And both of these were
           mentioned earlier this morning.  The first one was
           Quad Cities, and based on their initial analysis --
           and, again, these are plants who at some point in the
           process defined the vulnerability and said, "Yes, we
           have a vulnerability," and I'll clarify that.
                       In their initial analysis, Quad Cities did
           conclude that there were potential fire
           vulnerabilities.  It was associated with turbine hall
           fires, and, in particular, large oil fires in the
           turbine hall that led to loss of safe shutdown
           equipment and, in particular, cables that were routed
           through the turbine building to the reactor buildings.
                       There was a proximity issue associated
           with their remote shutdown panels that were also
           located in the turbine building.  As a result of those
           proximities to the fire, they took relatively low
           reliability for their operator recovery actions to
           take remote shutdown actions.  And there was also a
           fairly significant contribution from the reliance on
           the sister unit equipment for shutdown, and the outage
           time associated with the sister unit also turned out
           to be a fairly significant factor.
                       What Quad Cities did is under considerable
           attention from the NRC, both from Research and NRR,
           there was a requantification analysis performed.  And
           the ultimate conclusion of that reanalysis was that
           there were, in fact, no vulnerabilities remaining at
           the plant.  
                       The reanalysis relaxed some of the
           conservatism that was in the original analysis.  For
           example, there was some additional cable tracing. 
           They had assumed certain cables would be lost.  They
           went back, traced, found out that they were in
           different areas and took credit for that.
                       There was also some relaxation of system
           impacts.  They had assumed if any cable associated
           with a particular system were lost that system would
           be lost.  They relaxed that to say, well, certain
           cables aren't as important as others.  We may not lose
           the system function.  We may lose an indication or
           something else, but the system function would be
           there.  They took some credit for that.
                       And they also refined various aspects. 
           They dug a bit deeper.  They sharpened their pencil. 
           They looked into aspects of the analysis that have
           been handled in very simplistic ways and refined that. 
           And, in addition, there were some plant changes made
           in response to the initial analysis that were also
           credited in the reanalysis.  So, again, based on the
           reanalysis, they concluded that the vulnerability
           didn't exist.
                       MEMBER LEITCH:  Steve, my question would
           be:  is Quad Cities unique in this situation?  It
           would seem to me that many plants would have this kind
           of vulnerability.  And is it true that they do not? 
           Or was Quad Cities just -- just came upon this and
           others perhaps overlooked this vulnerability?
                       Because I guess what I'm saying is if Quad
           Cities made some changes to improve it, what about the
           other plants that might have similar vulnerabilities?
                       MR. NOWLEN:  Sure.  There were some unique
           things about Quad Cities, clearly.  There were aspects
           of the situation there -- in particular, the location
           of the remote shutdown panels in relative close
           proximity to these fires they were postulating --
           relatively unique.
                       In the IPEEE process, we did focus
           considerable attention on turbine buildings.  And so
           we asked a lot of licensees very specifically about
           their turbine buildings, and they typically responded
           with answers that satisfied us that there was not a
           similar situation there.
                       There are, of course, exceptions and one
           of them is our second vulnerability case, which was
           Millstone -- Millstone Unit 2.  In the case of
           Millstone the initial analysis concluded there were no
           vulnerabilities.  There was an outlier identified.
                       They didn't call it a vulnerability --
           they called it an outlier -- associated with storage
           of some transient combustibles in proximities to some
           important cables and they identified some resolution
           paths for that.
                       But in part because of knowledge of
           members of the Senior Review Board about this plant
           and things we had seen from Quad Cities, they were
           specifically asked about their turbine hall analysis. 
           And in response they did come back and say, "Yes,
           you're right.  We found a vulnerability in the turbine
                       In this case, they focused on two
           particular scenarios that each came in with an as-
           found estimate of risk that was very conservative CDF
           of on the order of 4E-4, conservative analysis,
           conservative assumptions.  The reason that they had,
           then, missed in the original analysis was that they
           had underestimated the CCDPs associated with these
           particular scenarios.  
                       And in this case it was the original
           analysis that assumed these CCDPs would be two times
           10-3.  And when they went back and looked again at
           what equivalent was going to be lost, they concluded
           it was one times 10-1.  So .1 -- very substantial jump
                       And so as a result, they implemented some
           improvements.  In particular, the turbine driven
           auxiliary feedwater vulnerability was fixed.  This
           basically derived from a vulnerability of that
           particular system, and they implemented changes to
           remove that vulnerability.
                       They weren't real explicit about exactly
           what those changes were.  But their requantification
           ultimately showed that the CDFs were on the order of
           2E-7 and 2E-8 for these two scenarios in particular. 
           So the fix really dropped the CDF quite considerably.
                       MEMBER LEITCH:  But it seemed to me in the
           Millstone case, from what I read hear, that initially
           it was like 10-7 or 10-8.
                       MR. NOWLEN:  Yes.
                       MEMBER LEITCH:  And then they --
                       MR. NOWLEN:  They screened, initially, in
                       MEMBER LEITCH:  Yes.  And then there was
           some attention brought to bear on this by the NRC and
           they --
                       MR. NOWLEN:  Yes.
                       MEMBER LEITCH:  -- looked at it and they
           said, "Ah, it's 10-4."  And then they did some fixes
           and brought it back up to 10-8 again.
                       MR. NOWLEN:  Correct.  Yes.
                       MEMBER LEITCH:  And I guess -- were these
           -- was there special attention given to Millstone as
           a result of the rest of the scrutiny that Millstone
           was under at this time?  I mean, I guess --
                       MR. NOWLEN:  No.
                       MEMBER LEITCH:  -- what I'm wondering is,
           would this have surfaced at another plant?
                       MR. NOWLEN:  Yes, we believe so.  Yes.  We
           asked a lot of licensees about their turbine halls. 
           Unless we got a really good analysis of the turbine
           hall that said, "We've looked at it in detail, and
           it's not important to us," or we got someone who did
           a good analysis and said, "Yes, it's an important
           area" -- and you'll see later that a lot of people did
           identify the turbine hall as an important fire area.
                       We asked a lot of licensees about that
           area and said, you know, "Look, we're not satisfied
           with the analysis you've done here.  Please give us
           more."  And we got a lot of good answers on that, and
           so a lot of people did go back.
                       And in this one particular case the
           vulnerabilities surfaced, but that was the only other
           case where the vulnerabilities surfaced.
                       VICE CHAIRMAN BONACA:  The reason why I
           asked the question at the beginning of the morning,
           the question that Graham is asking, because there are
           some sister plants which are pretty much identical in
           configuration, locations, etcetera.  So the question
           would be -- normally, when you have a finding like
           this, you go back and ask the other guys exactly the
           same issue.
                       Now, you were pretty unspecific about what
           the fix was, except in the text it speaks of the
           turbine-driven aux feed pump.
                       MR. NOWLEN:  Yes.  That was the -- for
           Millstone that was the extent of the information we
                       VICE CHAIRMAN BONACA:  So, you know, I'm
           left with the question -- did the other guys look the
           same way?  Didn't find it because of that?  Or is it
           something else?
                       MR. NOWLEN:  Well, again, all I can say is
           we did specifically focus licensees' attentions on
           this issue.  We directed them to consider what
           happened at Quad Cities, and later what happened at
           Millstone and Quad Cities.  And we asked them to
           consider similar issues for their plants.  And the
           answers we got back were, "No, we don't have the same
           kind of issue."
                       So we took that at face value and stopped,
           unless we had reason to, you know, say, "Well, wait a
           minute.  Your analysis missed this one point."  In
           some cases, we went back a second time and asked
           again, but ultimately in all of the other cases we
           were satisfied they had addressed it and didn't have
           a similar vulnerability.  Okay?
                       So jumping to plant improvements, we did
           see quite a wide range of plant improvements
           identified by licensees.  And it's worth pointing out
           that the status of these improvements, as in the case
           of seismic, isn't always entirely clear.  It includes
           things that were considered and rejected.  We've
           actually counted those.  
                       There's a few cases of that where people
           said, you know, we identified some things but decided
           they weren't cost effective or weren't of sufficient
           impact to pursue, things that were considered and
           implemented, things that were being considered, things
           that we're going to think about in the future, and
           things that were simply identified as a potential
           benefit without any real discussion of how that was
           going to be addressed.
                       But overall a majority of the licensees
           did identify at least one plant improvement.  And this
           was -- 44 of the submittals, 44 of the 70 submittals
           included at least one fire-related plant improvement,
           and that represented 62 units -- those 44 submittals. 
           And that's 64 percent of the submittals, so I think
           that's a good thing.
                       And the plant improvements, again, similar
           to seismic, they fell into three common categories and
           that's operating procedures and training practices. 
           That was almost half of the improvements that were
           associated with that.
                       Maintenance procedures and practices, a
           smaller number -- about 12 percent -- were associated
           with that.  And then physical design changes were
           fairly highly represented as well, and these ranged
           from minor things to fairly substantial things.  
                       So, again, there's a range in each of
           these, but a fair spread.  And, in particular, the
           physical design changes -- quite a good representation
           of changes beyond simple procedures.
                       MEMBER LEITCH:  We're under the impression
           that the February San Onofre event was made
           considerably worse by the fact that there were
           barriers missing between certain breaker compartments,
           and the fire propagated from one to the other.
                       MR. NOWLEN:  Yes.  And really --
                       MEMBER LEITCH:  Has that kind of thing
           surfaced as something which should be in a maintenance
                       MR. NOWLEN:  I can't recall anything like
           that, and I'm not familiar with the San Onofre event,
           so I don't have a lot of detail there.
                       MEMBER LEITCH:  Okay.
                       MR. NOWLEN:  But I don't recall things
           along those lines, no.
                       MEMBER LEITCH:  Okay.
                       MR. NOWLEN:  Okay.  Again, getting more
           specific, there were a range of issues identified in
           these improvements or addressed in these improvements
           -- emergency procedures, enhancements to identify --
           or to address identified fire risk scenarios.
                       For example, they would take scenarios
           that were identified in the IPEEE and look at their
           procedures and adjust them to reduce the likelihood
           that things would go bad in these events.  Operator
           training -- some of the licensees, for example, cited
           that they were using scenarios from the IPEEE process
           to develop new training scenarios for the operators,
           specifically simulating some of the things they were
           postulating in the IPEEEs in terms of scenario
                       Fire brigade training, an additional
           detail -- or additional attention to the firefighting
           and dominant fire areas -- in particular, pre-
           planning, additional fire drills, that was fairly
           commonly cited.  
                       General maintenance procedures tended to
           focus on things like housekeeping, transient
           combustibles, additional requirements for fire
           watches, reduction of fire hazards, that sort of
                       In terms of the physical changes, we saw
           cases of relocating equipment and cables to remove
           them from the critical fire area or to reduce the fire
           hazard associated -- or the fire hazard presented to
           those pieces of equipment.  Some fire protection
           system modifications and upgrades, fire barrier
           changes and upgrades that people were citing, and in
           a few cases we saw electrical design changes, system
           design changes -- in particular, plants who looked at
           spurious operation potential.
                       In a few cases we had plants that came
           back and said, "Well, we've made a design change to
           the system to reduce the likelihood of spurious
           actuation in order to reduce particular scenarios."
                       MEMBER POWERS:  The general category of
           spurious actuations, do you find any difference --
           consistent difference between those plants that have
           self-induced station blackout and those that do not?
                       MR. NOWLEN:  It's a tough question.  We
           did have --
                       MEMBER POWERS:  I wouldn't ask it if it
           wasn't hard.
                       MR. NOWLEN:  Yes.
                       We didn't, and we did, in fact, question
           a number of licensees regarding the issue of self-
           induced station blackout.  We did have access to the
           Brookhaven report on that subject, and during each
           review we would look at that report, and if it was a
           plant that fell into one of the categories we would
           specifically look at the submittal for that kind of
                       We typically didn't see it in the original
           submittals.  It would not be discussed.  We would then
           go back to the licensee and ask them a question about
           how they had addressed that.  
                       This gets wrapped up a bit into the
           general issue of main control room abandonment and how
           they did human factors for main control room
           abandonment.  The typical response we got back was
           that they considered that even looking at SSPO issues,
           the number they've used for reliability of remote
           shutdown reflects the probability that those
           procedures would fail and that they consider it
                       Others provided us with some additional
           detail as to what the SSPO procedures actually were
           and the rationale for concluding that their numbers
           were bounding.  But in general, I think it was
           discussed earlier today that human factors remains one
           of those areas that is something of a state-of-the-art
                       CHAIRMAN APOSTOLAKIS:  Human performance,
           not --
                       MR. NOWLEN:  Human performance, yes.  I'm
           sorry.  And I think we fall there here.  And, in
           particular, with regard to control room abandonment,
           our ability to really analyze those in detail is still
           an area of challenge for PRA.  And I think that's
           reflected here, and so the answer is a bit mixed.
                       MEMBER POWERS:  I guess -- I mean, what
           you've said is that it's a mixed bag for those that
           have self-induced station blackout.  What I was
           interested in was in those that -- the differences
           between those that do and those that don't in self-
           induced station blackout.
                       MR. NOWLEN:  You can't really tell,
           because it's all wrapped up in the control room
           abandonment.  And everyone tended to take fairly --
           well, not everyone, but the majority of licensees took
           fairly simplistic approaches to conservative analysis
           of control room abandonment.  
                       And so the distinction between SSPO and
           non-SSPO plants -- it gets washed out by the almost --
           the relatively simplistic approach that people took to
           conservatively estimating control room abandonment
                       MEMBER POWERS:  A lot of the text of the
           document speaks of these conservative analyses, and I
           was wondering, how do you know that they're
           conservative?  Is it plausibility arguments?
                       MR. NOWLEN:  Plausibility, the combined
           judgment of the Senior Review Board, the judgment of
           the reviewers.  You know, for example, if someone took
           a one in 10 probability that a remote shutdown failed,
           we generally said that's probably conservative and we
           accepted it.
                       MEMBER POWERS:  I'm wondering how you knew
                       MR. NOWLEN:  Judgment.  We're supposed to
           be experts.
                       MEMBER POWERS:  Well, I'm just trying to
           understand how you got that judgment.  I mean, how --
           since I'm not an expert, how would I become an expert
           in judging the probability of control -- alternate
           shutdown panel failure?  Or do I run 600 attempts with
           the panel, and if 60 of them fail then I know it's .1
           or --
                       MR. NOWLEN:  Yes.  It's a real -- it's a
           tough issue.  You know, again, you wouldn't ask if it
           weren't.  But we just had to use our own judgment. 
           You know, did we consider -- and, in particular, we
           took it in the context of the objectives of the IPEEE
           process.  Virtually all of the licensees acknowledge,
           yes, the control room is important to us, and it's a
           dominant contributor to fire risk.
                       Well, in the context of the IPEEE, that
           was -- the primary objective is, you know, have they
           acknowledged that they know where their risk
           contributors come from?  Whether they got exactly the
           right number we were less concerned with.  
                       And, again, recognizing that this brings
           in a number of state-of-the-art issues, we typically
           didn't pursue it to that level.  We said, you know,
           the licensee has acknowledged that this is an
           important area.  It shows up as one of their dominant
           contributors.  We can all argue about the number, but
           that's the answer.
                       Now, the ones we tended to focus on were
           the ones where we thought they had taken an overly
           optimistic view of control room fire risk and used,
           for example, very, very low probabilities of
           conditional -- or conditional probabilities of
           abandonment given a fire, or who had taken very, very
           high reliability values for remote shutdown.  Those
           were the ones that we tended to focus on and say,
           "Gee, guys, have you really thought hard about how
           important the control room might be to you?"
                       Is that satisfactory?
                       MEMBER POWERS:  Well, it's the answer.
                       CHAIRMAN APOSTOLAKIS:  If I look at
           Figure 3-5 on page 331, you have --
                       MR. NOWLEN:  I'm sorry.  Which page?
                       CHAIRMAN APOSTOLAKIS:  Page 331.  There is
           a simple -- there is a reporting of fire CDF versus
           the method of analysis employed.  Does it tell us
           anything?  It seems as if those which --
                       MR. NOWLEN:  Yes, we're jumping a little
           ahead.  I actually have --
                       CHAIRMAN APOSTOLAKIS:  Oh, okay.
                       MR. NOWLEN:  -- if you want to --
                       CHAIRMAN APOSTOLAKIS:  We can talk about
           it.  But this is speaking of the same -- it seems to
           me that the same approach is used, which is -- it
           seems to yield more conservative numbers.  I don't
           know if that was --
                       MR. NOWLEN:  Yes.  We're --
                       MEMBER POWERS:  Well, I mean, I really
           question --
                       MR. NOWLEN:  This is the figure you're
           referring to?
                       MEMBER POWERS:  -- whether you can draw
           that conclusion?  Because if they --
                       CHAIRMAN APOSTOLAKIS:  Well, that's why
           I'm asking the question here.
                       MR. NOWLEN:  Exactly.  Yes.  Our own
           perspective is that these are largely a wash.  You can
           see, for example, the FIVE studies, which we've called
           FIVE plus.  There is actually a very, very small
           number of studies you can call true FIVEs, that just
           did FIVE and stopped.  Everybody -- almost everybody
           did a little bit more.
                       But the FIVE studies tend to be a little
           bit higher.  They are screening, so you would kind of
           expect that, that if they stop at screening -- people
           who sharpen their pencil tend to get lower numbers. 
           But there is a lot of wash here.  
                       It's difficult to say there is a true
           trend here.  There is a lot of spread in the data, and
           they all overlap.  And so, you know, it's difficult to
           conclude that there is any real trend here, and our
           conclusion was that there is no real trend here.
                       There are some reasons that you can say,
           yes, that some of these we expected higher numbers,
           but also one thing to recognize is that in general
           screening was at 10-6 for fire compartments.  And once
           they had satisfied themselves that they were below
           that threshold it stops.
                       CHAIRMAN APOSTOLAKIS:  So how did these
           guys handle the issue of control room abandonment?
                       MR. NOWLEN:  A range of ways.  Which one? 
           The FIVE studies, in particular?
                       CHAIRMAN APOSTOLAKIS:  The FIVE studies.
                       MR. NOWLEN:  There was some analysis done
           that would typically begin with a fire frequency, and
           they would assign a conditional probability that given
           a fire they would abandon.
                       CHAIRMAN APOSTOLAKIS:  That's a key here
           because that's doing a screening analysis.
                       MR. NOWLEN:  That's a screening, yes.
                       CHAIRMAN APOSTOLAKIS:  They're very
           conservative there.  What kind of numbers do they use
           to be very conservative?
                       MR. NOWLEN:  To be very conservative, it
           was about .1 was about the most conservative that --
           so one in 10 fires would lead to control room
           abandonment with no screening of any of the events. 
           So you start with about a 10-2 fire frequency in the
           control room, a .1 on abandonment, and a .1 on remote
           shutdown failure, and you're at 10-4 control room.
                       We had a number of people who stopped
           there and said, "Yes, our control room is important. 
           We know that, and, you know, thank you."  And so, as
           you'll see, I've got some other slides that show some
           of these areas that contribute.  And there are,
           indeed, some 10-4 IPEEE estimated control rooms, and
           those tend to be that -- that's how you get 10-4 for
           a control room -- those three numbers multiplied
                       But, again, it varies.  You know, some of
           the FIVE studies went much deeper into the main
           control room and dug a lot deeper.  So it's really all
           over the board.
                       CHAIRMAN APOSTOLAKIS:  But there really is
           no basis for the .1.  I mean, it's --
                       MR. NOWLEN:  No.  No, you're right.  It's
           -- it doesn't have a good, strong, scientific basis. 
           Again, you have to use your judgment.  And, again, in
           the context of the IPEEE, the licensee says, "Yes, we
           know it's an important area.  You know, what more do
           you want us to say?"  And we said, "Okay.  Thank you." 
           And we kind of let them go at that point.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. NOWLEN:  Okay?
                       CHAIRMAN APOSTOLAKIS:  I don't think we
           should start with the perspectives now.
                       MR. NOWLEN:  Okay.  This is actually not
           a bad place to stop, so we can stop right there.
                       CHAIRMAN APOSTOLAKIS:  Take an hour, Mike? 
           Okay.  1:15.
                                   (Whereupon, at 12:14 p.m., the
                       proceedings in the foregoing matter went
                       off the record for a lunch break.)
                     A-F-T-E-R-N-O-O-N  S-E-S-S-I-O-N
                                                    (1:15 p.m.)
                       CHAIRMAN APOSTOLAKIS:  Okay.  Steve, keep
                       MR. NOWLEN:  Okay.  Returning to the
           presentation, we're on slide 9, beginning the
           discussion of CDF perspectives at this point.  The
           plot that we've shown here in this particular slide
           separates the plants in the BWRs and PWRs and shows
           the range of fire CDF results we got for those plants
           that did report CDF values.  Not all did that, by the
                       Compared to the IPE values for the
           corresponding group, I'll note that you can't compare
           the squares to the squares.  They don't plot that way. 
           This is just a distribution of the range for the
           entire population.
                       And the conclusion here is that, by and
           large, the IPEEE fire CDF values are in the same range
           as the IPE internal events values.  They are
           relatively comparable here.
                       MEMBER POWERS:  Let me ask you a question
           about CDFs, not that I argue with your conclusion for
           this plot, but there are some -- how do we get these
           CDFs?  You have some features that are, in fairness,
           highlighted in the report but raise some questions in
           my mind. 
                       It says, "Most licensees screened all
           scenarios involving propagation of a fire from one
           zone to another.  The rest reported CDF contributions
           for fires ranging from one percent," which I'll admit
           sounds pretty insignificant, "to 30 percent," which is
                       MR. NOWLEN:  Well, 30 percent of what,
           though?  If it's already --
                       MEMBER POWERS:  Of the overall fire-
           induced CDF.
                       MR. NOWLEN:  Yes.  But if the fire CDF is
           1E-7, and 30 percent of that comes from the --
                       MEMBER POWERS:  Yes.  But what about 1E-4?
                       MR. NOWLEN:  They didn't report 30 percent
           due to room to room, so --
                       MEMBER POWERS:  What did they report room
           to room?
                       MR. NOWLEN:  No one found room-to-room
           scenarios to be a dominant contributor to CDF.
                       MEMBER POWERS:  Well, dominant -- three
           percent is not dominant, but it's not negligible
                       MR. NOWLEN:  Yes.  Okay.  That was perhaps
           misphrased.  No one found room-to-room scenarios to be
           a high contributor to CDF.  They were all finding
           relatively low numbers for room-to-room scenarios.
                       Now, in one particular case we did have a
           plant who found some room-to-room scenarios that
           turned out to be relatively important in comparison to
           other rooms.  
                       But, again, that -- if I recall correctly,
           that particular case is a plant that has a low CDF to
           begin with.  And so the room-to-room scenarios are
           also low.  This is a relative contribution for that
           particular --
                       MEMBER POWERS:  If I understand what's
           said here, you're making all of these conditional
           statements based on 20 percent of the submittals.
                       MR. NOWLEN:  Yes.  In the room to room
           that is true.  There was a limited sampling of the
                       MEMBER POWERS:  Okay.  If I looked at the
           others, would it raise all of these numbers?
                       MR. NOWLEN:  No.  No, it wouldn't.
                       MEMBER POWERS:  Well, it would at least by
           perhaps as much -- as little as one percent.  In some
           cases 30 percent.
                       MR. NOWLEN:  Well, I think I've lost you. 
           You know, the worst -- the most significant in a
           relative sense for any given plant that room-to-room
           scenarios was cited as was 30 percent of the total CDF
           came from room-to-room fire scenarios.
                       MEMBER POWERS:  Right.
                       MR. NOWLEN:  Again, that was a plant that
           had a very low fire CDF.  So we have to take that
           number with a grain of salt.
                       MEMBER POWERS:  Maybe you need to make
           these things clear, because otherwise --
                       MR. NOWLEN:  Perhaps.
                       MEMBER POWERS:  -- I think this is a very
           provocative statement, and it really raises questions
           about whether they found their dominant fire scenarios
           in the course of doing this work, because if they go
           through and assume there's no propagation in between
           things, except for a few who find it's a 30 percent
           contributor, then I would really question whether you
           have found the dominant contributors.
                       MR. NOWLEN:  Yes.  And then, again, you
           have to take these in the context of the absolute
           numbers.  And you're right.  In this case, we should
           clarify that in the report.  You know, we didn't get
           30 percent of a 10 to the minus -- you know, we didn't
           get -- Quad Cities wasn't 30 percent room to room. 
           These were plants that were in the -- probably as I --
           I don't recall the details of this particular case. 
           But typically in the, you know, high 10-7, low 10-6
           range, with numbers in the low 10-7 range coming from
           room-to-room scenarios --
                       MEMBER POWERS:  It's a non-trivial
           consideration, because we spend an enormous amount of
           time and resources chasing around on these fire
           penetration barriers.  And what we'd really like to do
           is look at the risk significant ones, and what you're
           really saying is that there aren't any risk
           significant ones.
                       MR. NOWLEN:  The IPEEEs didn't identify
           any risk significant ones.  That is correct.
                       MEMBER SHACK:  Does that includes the ones
           where they just sort of gave up and combined things? 
           That isn't counted as a room-to-room thing?  They just
           gave up and assumed it was all one room?
                       MR. NOWLEN:  No.  If they, in the end,
           treated it as all one room, then that's one room.  It
           would not be a room-to-room scenario anymore.  And
           there were cases of that as well.
                       We saw cases going both ways, in fact,
           where they began with a large room, and at some point
           in the analysis they decided to cut it into smaller
           pieces.  We also saw cases where they initially cut
           things into smaller pieces and said, "It's
           unnecessary.  We can recombine it, and it's still
           small, so why don't we do that."  And so there were
           cases both ways.
                       Ultimately, the bottom line is if they
           cited it as a single room number, we cited it -- we
           treated it as a single room number.  If they cited it
           as this is a room-to-room scenario, then we treated it
           that way.  
                       But you're right, yes.  And the answer is
           that room-to-room scenarios did not present high-risk
           scenarios for the IPEEEs.  That's not where the higher
           CDF values were coming from.  They were coming from
           other areas, individual areas.
                       MEMBER LEITCH:  Steve, I know it's not
           really the point of that viewgraph, but I was
           wondering if those two very low CDFs for BWR fire and
           BWR internal events, are they the same plant?
                       MR. NOWLEN:  Yes.  Yes, they are.  That's
                       MEMBER POWERS:  Yes.  We've got to find
           out what Susquehanna's fire protection program is, and
           just put that in the NFPA 805 and let it go at that.
                       MR. NOWLEN:  Well, again, there was
           considerable attention paid to that particular number. 
           They looked at it in the review process in pretty
           close detail.  Ultimately, you know, the number is
           still very, very low in comparison to the other
           plants.  Of course, we take it with a grain of salt,
           but in --
                       MEMBER SHACK:  Is their performance during
           fire as good as it is for internal events?
                       MR. NOWLEN:  I can't answer that question. 
           I don't know.  I would -- well, no, I don't want to
                       MR. RUBIN:  Yes.  I think that was one of
           the issues, yes, definitely.
                       MR. NOWLEN:  It jumps out, yes.
                       MEMBER LEITCH:  You're questioning the
           validity of the results without -- just on the face of
           it, I guess is what I'm saying.
                       MR. NOWLEN:  But, again, this was a case
           where there was a Level II review, and so they went
           down to the plant and they had extensive discussions
           with them, and the review team satisfied themselves
           that this was a -- you know, that there weren't
           outstanding vulnerabilities to be identified here,
           that, you know, despite whether you agree with that
           number or not, it's not a 10-3 plant, for example.
                       And so, again, within the context of the
           IPEEE, that satisfied our objectives, and we moved on. 
           In this case, we kind of agreed to disagree with the
           utility on that one.
                       MEMBER LEITCH:  Yes, okay.
                       MR. NOWLEN:  Another interesting thing is
           that if you start looking at them individually, and we
           did avoid this to a large extent in the report -- we
           didn't want to compare one plant's fire to one plant's
           IPE directly and present all of those results.  
                       But if you do make such comparisons, you
           find that the vast majority of the submittals do
           report a CDF value that's within one order of
           magnitude, in fact, of the IPE internal events CDF for
           the same plant.  
                       There is a small number of licensees who
           didn't report CDFs, and those, in particular, are the
           FIVE-only studies.  They were small, they did FIVE,
           stopped, so you get a screening answer, and it's not
           a CDF.  We didn't include those.
                       Another thing that we saw, or didn't see
           I should say, is any definitive trend of CDF with
           plant vintage.  We did specifically look at this, and
           there is a plot in the report that shows it.  You see
           this is -- the operating license is the value that we
           chose to plot against, the date of the operating
           license.  And, again, that's a shotgun blast.  There
           is no tremendous trend there.  It's very, very flat,
           in fact.
                       MEMBER POWERS:  Did you do any kind of
           formal regression analysis to try to separate out
           factors in these -- this shotgun blast?
                       MR. NOWLEN:  No, we didn't.
                       The other point that we looked for and
           didn't especially see -- and we actually talked about
           this already -- is that there was no real definitive
           trend based on the method applied.  There are some
           weak trends that you can sort of anticipate, and you
           do see those.  
                       But again, statistically, it's difficult
           to say that there's a real trend.  The FIVE studies,
           again, tend to solve marginally higher CDFs.  They
           tended to stop at a lower level of detail. 
           Presumably, sharpening the pencil would further reduce
           those values.  And other than that, they tended to
           yield nominally similar results.
                       What I want to go into now is where were
           the dominant fire CDF contributors?  And I'm going to
           cover it -- talking about it by fire area or fire
           zone, and by the types of initiating events that were
           analyzed and in terms of the fire sources that they
                       So in terms of the fire areas and zones,
           the main control room is the one that was most
           commonly identified as the dominant contributor, and
           it was -- the main control room analysis itself was
           typically dominated by the abandonment scenarios.
                       MEMBER KRESS:  What was the criteria used
           for abandonment?  If the --
                       MR. NOWLEN:  There tended to be different
           criteria.  The most commonly applied criteria is the
           criteria you find in the fire PRA implementation
           guide.  It basically did an interpretation of testing
           done by Sandia under USNRC sponsorship in the 1980s.
                       They interpreted the time it took for the
           smoke layer to descend to eye level, which is one of
           the things we reported in those studies.  And then,
           based on the conditional probability that you put the
           fire out within that same time period, failure to
           suppress would lead to abandonment.
                       So the typical number -- when you do that
           analysis according to the PRA guide, it comes out .07,
           I believe -- 007?  007, yes, 7E-3.  So that was the
           most commonly applied number.
                       There was considerable discussion of that
           approach.  It became one of the areas that was
           discussed with EPRI with regard to the fire PRA
           implementation guide.  Our ultimate resolution there
           was that so long as they did not screen those
           scenarios on that basis, the probability of
                       And that they continued and provided an
           analysis of remote shutdown, we accepted the number
           for the purposes of the IPEEE.  But, yes, that was the
           most common.  There were some others.  Some people
           took conservative numbers; some took more optimistic
                       CHAIRMAN APOSTOLAKIS:  Again, I'll repeat
           the comment I made earlier for the seismic analysis. 
           You state in the report -- and I think you just said
           it again -- that the human error probabilities varied
           widely.  There is no really strong technical basis,
           and so on.
                       And yet when it comes to discussing fire
           methodology perspectives, there's no mention of human
           error.  Again, when we say fire methodology, we mean
           fire growth and suppression, or you also mean the
           scenario.  So it seems to me that there should be some
           discussion of that, because this is one of the most
           important elements.
                       MR. NOWLEN:  Yes.  I'm surprised.  There
           is a discussion of human reliability or human
           factors --
                       CHAIRMAN APOSTOLAKIS:  There is a
           discussion separately?
                       MR. NOWLEN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  In the section that
           says Fire Methodology Perspectives, there is no
           mention of it.
                       MR. NOWLEN:  I see.
                       CHAIRMAN APOSTOLAKIS:  You know, if I were
           to decide --
                       MR. NOWLEN:  Yes, we culled it out as a
           separate section of the report --
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MR. NOWLEN:  -- but it's -- it is a part
           of the methodology.  But, yes, it was culled out as a
           separate section.  But there is a fairly considerable
                       We did see something a bit different in
           the fire area than we saw in some of the other areas. 
           Fire tended to be more binary.  Typically, they began
           by crediting what's in the IPE, and then it was more
           commonly a binary.  Either we're going to credit that
           action or we're not going to credit that action.
                       Relatively few people use performance
           shaping factors, for example.
                       CHAIRMAN APOSTOLAKIS:  Yes, and there were
           between five and 10, as you state in your --
                       MR. NOWLEN:  Right.  Yes.
                       CHAIRMAN APOSTOLAKIS:  And those -- you
           know, sometimes, especially in a field where we don't
           know much, people are dying to find somebody's report. 
           I found out after 10 phone calls that a number that I
           was trying to track down a few years ago originated
           from me.
                       I'm serious.
                       MR. NOWLEN:  It's disconcerting, isn't it?
                       CHAIRMAN APOSTOLAKIS:  Not 10 calls, but
           four or five.  I said, "No, this guy told me, this guy
           told me," and then finally the guy says, "Well, you
           told me."
                       So here we have an EPRI document which was
           used by people who found that the suppression of fire
           within 15 minutes or non-suppression is 3.4 10-3.  I
           mean, that's a very low number.
                       MR. NOWLEN:  Oh, that's the correct
           number, yes.
                       CHAIRMAN APOSTOLAKIS:  But if it comes
           from a document from a major organization, I guess it
           has some weight.  But I'm sure it's just judgment,
           somebody's judgment.
                       MR. NOWLEN:  No.  It was actually based on
           an analysis.
                       CHAIRMAN APOSTOLAKIS:  Based on actual
                       MR. NOWLEN:  Yes.  They did an analysis of
           the events in the fire event database, developed a --
                       CHAIRMAN APOSTOLAKIS:  10-3 as a time?  As
           a function of time?
                       MR. NOWLEN:  I'm sorry?  Nathan?
                       MR. SIU:  This is Nathan Siu, Office of
           Research.  The -3 number, basically what it comes from
           is a very small number of control room fires.  I think
           it was four.  And they had the times to extinguishment
           for those, which were pretty much clustered -- very
           short times.
                       They assumed that the time to suppress was
           log normally distributed, so they basically fit the
           curve to that, and then read off the tail to say,
           "Okay.  Look at 15 minutes or whatever the appropriate
           number was."  So there is some development there, but,
           again, you can obviously question the basis.  And
           that's why we had a lot of discussions on that
                       CHAIRMAN APOSTOLAKIS:  It's a lot of
           judgment.  I'm not blaming you for -- I mean, I'm just
           stating that the -- you know, there are some numbers
           that are pretty low, and the performance shaping
           factors of five and 10 -- that is all judgmental. 
           It's the same in the seismic area, and I think this
           report should make a big deal out of it.
                       MEMBER KRESS:  It seems like an insight,
           doesn't it?
                       CHAIRMAN APOSTOLAKIS:  It is a major
           insight, yes, a major insight.  And, again, if we come
           to GSI 172, I don't know if there is a fire example
           that you guys can show us of these 61 units that
           supplied sufficient information to resolve the issue,
           because 172 is not limited to seismic.  Is it?  It
           includes fires.  It's multiple system responses
                       MR. NOWLEN:  Yes.  There are fire --
                       CHAIRMAN APOSTOLAKIS:  I'd like to see
           fire, too, to -- just to learn what was considered
                       MR. NOWLEN:  Okay.
                       CHAIRMAN APOSTOLAKIS:  Another unique
           issue with the fires, it seems to me, Steve -- and we
           have not discussed it very much, if at all -- is not
           just the human error but the severity factors.
                       MR. NOWLEN:  Oh, absolutely.  Yes.
                       CHAIRMAN APOSTOLAKIS:  It seems to me that
           the severity factors is destined -- are destined to be
           there forever, because I don't see how we can get data
           to -- to tell us what percentage of fires is large
           fires, and so on.  Does everyone know what severity
           factors are?
                       MR. NOWLEN:  I do have a discussion on
           this in a couple of slides.  But --
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. NOWLEN:  -- and Nathan may choose to
           jump in at that point as well.
                       CHAIRMAN APOSTOLAKIS:  Fine.  We'll
           revisit them then.
                       MR. NOWLEN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  But it's a major
           issue with fires.
                       MR. NOWLEN:  It is.
                       CHAIRMAN APOSTOLAKIS:  It's not an issue. 
           It is an issue, I guess.
                       MR. NOWLEN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  But it's a very
           essential part of the analysis, and it has to be
           judgmental, because, you know --
                       MR. NOWLEN:  Yes.  And it did become a
           considerable point of focus, but --
                       CHAIRMAN APOSTOLAKIS:  But that brings
           down the frequencies by two or three orders of
           magnitude, does it not?
                       MR. NOWLEN:  Depending on how they're
           applied.  We typically saw one, but we did see cases
           of three or four, yes.
                       CHAIRMAN APOSTOLAKIS:  All right.
                       MR. NOWLEN:  Okay?  Let's see.  Okay. 
           Dominant fire areas -- again, another area -- switch
           gear rooms, the emergency switch gear rooms in
           particular, and the scenarios here tended to be panel
           fires leading to damaged overhead cables.  These
           showed up a lot.  Again, that's pretty consistent with
           what we've seen in past PRAs.
                       The third area here is turbine buildings. 
           We've already discussed turbine buildings a couple of
           times.  Often times these were large oil fires that
           led to the large contributions in the turbine hall,
           and there were a fair number of licensees who reported
           their turbine halls as high contributors in their
                       A little bit of a surprise compared to
           past PRAs.  The past PRAs have tended to be at plants
           that just didn't turn out to be much of an issue.  In
           this case, we had a fair number of licensees who did
           identify that.
                       Other areas that we often wonder about in
           fire PRA - cable spreading rooms.  In this particular
           case, the answer tended to be driven by how many cable
           spreading rooms there are.  Again, not incredibly
           surprising.  If there were more than one cable
           spreading room separated with train segregation, then
           they tended not to be important.
                       The other factor was the type and nature
           of the fire sources that were in the room.  If it was
           strictly a room full of cables, they tended not to be
           important -- fire frequency very, very low for self-
           ignited cable fires.  Whereas if they had panels in
           the room, then the fire frequency pumped up.  You had
           a higher contribution in general.  Again, not too
           surprising, fairly consistent with what we've seen in
           the past.
                       We also saw various types of electrical
           equipment rooms in certain plants that have a lot of
           the control room equipment that gets relocated to a --
           what you would normally expect to find in the control
           room gets relocated to an electrical -- auxiliary
           electrical equipment room.  Those areas tended to show
           up as very important as well.  So those were real
           common, fairly typical of what we see, perhaps with
           the exception of turbine buildings, so far.
                       Others -- diesel generator rooms.  These
           were often associated with loss of offsite power
           scenarios, not too surprisingly.  Although, again, we
           don't typically see those diesel generator rooms
           showing up as dominant in past fire PRAs, so that's --
           for some plants that turned out to be important.
                       Cable vault and tunnel areas -- again,
           something we see in past PRAs has been found
           important.  Kind of a mixed bag in the IPEEEs.  It
           depended a bit on how they treated their transient
           combustibles.  Many of the submittals took substantial
           credit for administrative controls on transient
           combustibles in such areas, argued that they weren't
           to access during normal operation, and argued very low
           frequencies, so they tended to go away.
                       But, again, if there were other ignition
           sources, that brought them back.  In a number of cases
           we did ask licensees about their treatment of
           transient combustibles, and they would come back and
           say, "Well, okay.  If we do that, here's a new
           number."  So this is another area where we've tended
           to question the results and often got a somewhat
           higher number with the response.
                       And then another one that tended to be
           very plant-specific -- a few cases -- battery/charger
           rooms popped up as important contributors.  And,
           again, these were typically due to plant-specific
           factors.  There happened to be some cables routed
           through that area that turned out to be very
                       Moving on to the accident sequences, this
           was a really tough area for us to try and glean
           insights.  The information that we got in the
           submittals was typically fairly sparse in this area. 
           We would generally get a description of what accident
           sequences were considered in the analysis.  
                       But then when it came down to
           quantification and saying this particular scenario is
           associated with this sequence, we typically didn't get
           that level of detail.  Licensees weren't asked to
           provide that level of detail, and we didn't get it.
                       We didn't generally pursue that as an RAI
           issue unless we felt it was important, that we really
           wanted to know what was going on here.  Then we would
           ask licensees to tell us about what the scenarios
           were.  If they had provided us with no information at
           all about what sequences had been modeled, we would
           ask that question.
                       But where we do have information, the
           general plant transients tended to dominate.  It may 
           not be especially a robust conclusion -- again,
           because of the sparsity information.  It's based on
           relatively few submittals that gave us that level of
                       There were also cases that we saw of
           transient-induced LOCAs, stuck open PORV valves, some
           limited cases involving spurious operations, valve
           operations typically, and then the RCP seal LOCAs for
           the Westinghouse PWRs -- we saw a few of those crop up
           as important for those plants.  
                       And that's about all we have to say about
           those.  Again, a relatively sparse area in terms of
           the documentation we got.
                       When you look at the contributors in terms
           of the fire sources, in general there was a lot of
           attention paid to the electrical panel fires in the
           IPEEEs themselves.  The licensees spent a lot of time
           looking at panel fires.  They did dominate the
           analysis for a variety of areas -- the main control
           room, cable spreading rooms that had panels in them,
           switch gear rooms obviously, and these electrical
           equipment rooms.  Those all tended to involve panel
                       The potential for damage to overhead
           cables and how that was treated was often a critical
           factor in what their contribution ultimately was, and
           that was dependent in part on the fire size that they
           assumed.  These tended to be point estimates.  There
           was a most likely fire size assumed.  That was
           propagated through the analysis, and a zone of
           influence was assessed, and they would look at what --
           within that zone of influence.
                       So, again, the electrical panel fires were
           the most typical contributing source.  The other most
           commonly cited one was large oil fires.  Again, this
           was often -- turbine halls would also, in certain
           other pump areas where you have large oil sources,
           they would typically crop up as important.
                       Transient fires rarely were found to be
           the important fire sources.  In some cases, this is
           due to treatment, in fact, because typically if a
           licensee went in and said, "Well, I've got all of
           these fixed fire sources, and they're doing all the
           damage anyway.  So I'm going to lump my transient fire
           frequency in with the fixed sources and I've bounded
           the problem."  That was not at all uncommon.  Quite a
           few licensees did that.
                       So you tend not to get a separate split
           out of, what did the transient fires actually
           contribute?  Unless you want to do the ratio of how
           much of the fire frequencies --
                       CHAIRMAN APOSTOLAKIS:  In how many cases,
           though, did they argue that there is not enough --
           there are not enough combustibles in the room?  So
           we'll screen it out.  That's when the transient
           combustibles become --
                       MR. NOWLEN:  Yes.  We did get a lot of --
                       MEMBER KRESS:  And transients I think are
           more likely during shutdown conditions.  And I don't
           know if this included shutdown conditions at all.
                       MR. NOWLEN:  It did not include the
           shutdown conditions.  And that observation has been
           made by -- before.  
                       In this case, back to George's question,
           the areas that we tended to focus on for transient
           combustibles in the review process were exactly those
           ones you cite -- the areas where there weren't other
           fix sources present, and those areas where they were
           screened out based, for example, on administrative
                       We generally did not accept that as an
           argument in and of itself to screen an area -- say,
           well, I've got administrative controls, therefore, I
           consider them so unlikely that I don't even have to do
           any more evaluation.  
                       We questioned those whenever we ran into
           them and asked them to provide an explicit treatment
           of transient combustibles for those areas.  And in
           response the licensees would come back with a
           reanalysis that would give us a revised estimate.
                       And, again, even then the answers tended
           to be relatively low contributions by the time you
           take a fire frequency and a partitioning factor for
           location and then you propagate it through the fire
           modeling and credit suppression and things of that
           nature.  In some cases, severity factors would be
                       Let's see.  Self-ignited cable fires was
           an area where most of the licensees screen these as
           fire sources.  In particular, all of the newer plants
           that had the newer style cable followed the FIVE
           methodology guidance that said these fires apply only
           to the older, unqualified cables.  So if you have all
           qualified cables, you can screen them.
                       So the newer plants did that.  And even
           for the older plants, the pre-1975 plants in
           particular, most of them cited that they had back-
           qualified their cables in the Appendix R days to the
           flammability criteria of IPEEE 383.  So they screened
           them as well.
                       There were relatively few plants that did
           include them explicitly and treated them.  And, again,
           for those cases they tended not to be very dominant. 
           They tended to be low contributions.
                       Okay.  Jumping ahead -- getting into
           methods and modeling issues.  Again, I've mentioned
           that we grouped these submittals in different ways or
           into different groups.  The FIVE -- in this case, the
           FIVE plus the fire PRA guide studies, the ones that
           began with FIVE and then moved into the PRA guide, the
           ones who began with FIVE and then moved into other
           types of PRA analysis not specifically referencing the
           PRA guide, and those who jumped straight in to doing
           a PRA from the get-go.
                       The selected -- again, I've covered this. 
           It didn't seem to have a big impact on the CDF.  There
           are some trends, but it's really hard to pull anything
           specific out of it.  And one point to make here is
           that as with the other aspects of the IPEEE there is
           one or more minor weaknesses that exists in virtually
           all of the submittals.
                       For example, most of the submittals did
           not include a detailed human factors analysis.  And we
           considered that to be a weakness of those submittals. 
           The most common exception was the MCR abandonment
           scenarios.  We did get a number of licensees who did
           human factors analyses for those.  
                       And we typically saw that they were
           crediting the recovery actions that were modeled in
           the IPE.  In those cases, we typically looked to
           ensure that they had considered whether those modeled
           actions were reasonable given the context of the fire. 
           And in some cases, plants would go back and reexamine
           their credited actions and would eliminate those that
           were associated with, for example, actions within the
           fire area that you're analyzing and would take those
                       Our biggest concern here was some guidance
           in the fire PRA implementation guide that had
           suggested that you could do screening using the IPE
           event trees directly.  And since those included those
           human actions, you're potentially screening by
           crediting human actions that may not be possible.  We
           focused in particular on those and asked licensees to
           go back and reexamine their screening if they didn't
           credit those types of human actions.
                       MEMBER POWERS:  Is there a database, so
           that I can -- if I hypothesize a fire of a particular
           time at a particular location, I can estimate the rate
           of smoke generation?
                       MR. NOWLEN:  A database?  There are models
           that do that kind of thing.  They tend not to be the
           models that are applied in this context.  But there
           are simulation models that do that kind of thing.
                       MEMBER POWERS:  I guess what I'm asking
           is, when you ask the licensees to consider, I hope you
           ask them to consider the effect of fire and not the
           affect of fire.
                       MR. NOWLEN:  Yes.  
                       MEMBER POWERS:  Heat, smoke, and stress. 
           Do they have a good estimate of what the smoking rate
                       MR. NOWLEN:  No.  No.  They don't go to
           that level.  Typically, it's a judgmental assessment
           of whether or not smoke is likely to build up in a
           particular area.  And, again, the typical response was
           if it's the area that has the fire in it, you just
           don't credit the actions.  And that -- in fact, based
           on other work, you know, that may be somewhat
                       The other specific example that we ran
           into was the control room.  Typically, in the control
           room they said things happening in the control room
           are not impacted by fires occurring outside the
           control room.  That may be a little optimistic.
                       But, again, it was very typical.  We
           didn't argue that point especially.  You know, again,
           this is an area where there is still challenges for
                       MEMBER LEITCH:  There's a discussion in
           Appendix B concerning heat loss factors.
                       MR. NOWLEN:  Yes.
                       MEMBER LEITCH:  -- gas layer modeling. 
           And it left me a little confused.  Apparently, a
           classical number has been .7, and there was some other
           information that perhaps .95 could be used, and that
           turned out to be not -- that turned out to be non-
           conservative.  And I guess was that number -- my
           question is:  was that number actually used any place,
           or did everybody go with the .7 number?  Or how did
           that work out?
                       MR. NOWLEN:  Okay.  Ultimately, all of the
           licensees used one of two numbers -- either .7 or .85. 
           Okay?  And there were -- there was guidance that was
           developed by EPRI, in cooperation with NRC.  We worked
           with them to develop the guidance.
                       A little background -- let me back up one
           step.  The heat loss factor is a simplified way of
           treating heat losses to the walls and the ceiling
           during a fire event.  Most fire models treat that
           directly.  They do heat transfer and the walls absorb
           heat and it goes away.
                       But under the FIVE methodology, there's a
           simplified correlation for estimating how hot the hot
           gas layer will get based on how much heat comes into
           the room.  But since a fraction of that heat goes into
           the walls and is no longer available to heat the air,
           we take away part of the heat.
                       Well, the heat loss factor is that
           fraction of the heat that we take away.  So .7 says
           you're taking away 70 percent of the heat.  You've got
           30 percent left to heat the air.  It's a simplified,
           back-of-the-envelope kind of approach.
                       When the original methodology FIVE was
           developed by EPRI, the recommendation was use .7, it
           seems to work well, and it seemed relatively
           consistent with the data that was out there.  The fire
           PRA implementation guide came out with new guidance
           that said, well, in some cases it might be as high as
           .97, .95, .85, and so they recommended new guidance to
           use a new number.
                       And there was considerable discussion of
           that.  We did some comparison with -- of the
           correlation to test data using the different numbers. 
           And as you say, the numbers tended to come out -- the
           new numbers were non-conservative for the vast
           majority of cases.
                       Again, now back to your question, we
           ultimately settled on the two numbers -- .7 and .85. 
           And the difference here was another aspect of the EPRI
           methodology.  And this aspect was the virtual height
           of the fire.  Where am I putting the fire?  Do I put
           it on the floor?  Do I put it on the top of an
           electrical panel, for example?  
                       Do I put it at the location of --
           typically, under the FIVE methodology, if you put the
           fire on top of a panel, then you assume the hot layer
           would only descend to that level, the level of the
           fire, and wouldn't go any further.  So you would use
           only the volume of the room above that point.
                       If you put it on the floor, you use the
           entire volume of the room.  Okay?  What we came down
           to is that if you had the fire source elevated well
           above the floor, there was a criteria developed.  If
           you put it up high above the floor, then you could use
           the higher heat loss factor.  If you modeled the fire
           on the floor, you used the .7.  
                       And there are cancelling effects.  Because
           you've reduced the volume you end up with the same
           temperature, which is really what we expect given the
           same fire, whether it's up there or down here.
                       MEMBER LEITCH:  Okay.
                       MR. NOWLEN:  So that's how that got ironed
                       MEMBER LEITCH:  So no one actually used
           the .97.
                       MR. NOWLEN:  Not in the end, no.  They all
           went back and reexamined and applied the new numbers.
                       MEMBER LEITCH:  Thanks.
                       MR. NOWLEN:  Okay.  Let's see, have I
           covered this one?  Yes, I think so.
                       MEMBER POWERS:  I don't know whether this
           is the point to discuss fire growth modeling, or are
           you going to come to that?
                       MR. NOWLEN:  I didn't really present
           anything here on fire growth modeling.  There is a lot
           of detail in the methods, and I was selective on how
           much of that I have covered.  If you want to go there,
           I'm prepared.
                       MEMBER POWERS:  Well, one of the things
           that continues to bother me about how you model these
           fires is taking probabilities, applying them together,
           on things that are not transparently independent.  For
           instance --
                       MR. NOWLEN:  Sure.
                       MEMBER POWERS:  -- you have an area with
           a geometric factor, and you take some probability of
           the fire -- where the fire is located, and then you
           take some probability of the severity factor, and you
           multiply them together to get the amount.
                       Do you see a lot of that kind of stacking
           of probabilities on things that are not transparently
           independent quantities?
                       MR. NOWLEN:  We saw some of that and
           attacked it where we saw it.  The most common area was
           severity factors overlapping other aspects of the
           analysis.  For example, if you're going to do a
           severity factor that credits most fires are small, and
           don't cause any damage, which was not at all uncommon,
           then when you go to the detection suppression analysis
           you need to base that on the fact that I'm now, by
           definition, treating a large fire, because I've
           eliminated all of the small ones.
                       We did see a bit of that, and we did
           attack it fairly vigorously when we saw it.  And the
           typical response was a revised estimate that would
           eliminate the double counting factors.
                       For example, a lot of people use severity
           factors in lieu of a detection suppression analysis. 
           They said, you know, "Look, only one in 10 fires is
           going to cause any damage, so I'll take a .1 and move
           on.  And I'm going to skip detection suppression
                       We weren't entirely happy about those.  It
           tends to drive you towards a generic answer rather
           than a plant-specific, case-specific answer.  But so
           long as we felt it was within the bounds of what we
           would get from a detection suppression analysis, we
           accepted it and said, "Well, again, within the context
           of the IPEEE identifying vulnerabilities, okay."
                       But, you know, we did see various cases of
           that.  And, again, we did attack it when we saw it.
                       MEMBER POWERS:  The COMPBRN code gets used
           a lot in these analyses.
                       MR. NOWLEN:  If I can correct -- the
           COMPBRN code wasn't used a lot in the IPEEEs.  A lot
           of people used the FIVE modeling worksheets.  That was
           by far the most common.  Relatively few actually went
           to COMPBRN and IPEEE.  But, yes, when they used codes,
           COMPBRN was the code of choice.
                       MEMBER POWERS:  The question comes up --
           COMPBRN was written with a set of assumptions and
           hypotheses.  At least I tend to have seen people use
           COMPBRN fairly indiscriminately.  Did people tell you
           about when they applied COMPBRN and when they did not?
                       MR. NOWLEN:  I would say yes, because the
           people who used COMPBRN tended to be the PRA studies,
           the folks who jumped straight into PRA.  And those
           were typically done by people who were well versed in
           fire PRA, and they used them in the way that they have
           traditionally been used in fire PRA.  
                       So with the people who did COMPBRN
           studies, we had occasional issues about it, but it was
           typically choice of parameters.  For example, what did
           you use for your ignition temperature?  What did you
           use for the damage temperature?  Things of that
           nature.  Rather than fundamental abuse of the model. 
           Again, far more common in the IPEEEs was use of the
           FIVE spreadsheet approach.
                       MEMBER POWERS:  And certainly you
           highlight the indiscriminate use of the glamorous fire
           for every cable-to-cable transition known to man.
                       MR. NOWLEN:  Yes.  That was another one of
           the fire PRA implementation guide issues, the fact
           that a single fire test -- it was a USNRC test at
           Sandia, 1975.  That was used to develop guidance for
           how fires would propagate from tray to tray.
                       And, yes, we had considerable difficulty
           with the concept that you could extrapolate that to
           all conditions.  And, ultimately, those were typically
           purged from the final answers.  When questioned, most
           licensees went back and just simply got rid of it and
           said, "Okay.  We'll do it a different way."
                       So you -- I think you will have a very
           hard time finding any of the final analyses where that
           really played any role at all.  Yes.  And we did --
           again, that was one of the generic RAIs that was
           addressed with EPRI.
                       MEMBER POWERS:  Do you have a set of
           documents for each of the submissions that you are
                       MR. NOWLEN:  Yes.  For each of the
           submittals there is typically a technical evaluation
           report written by the reviewers, and there is a staff
           evaluation report.  There is also a collection of RAIs
           -- one, two, perhaps three rounds of RAIs, and, in a
           more limited number of cases, site audits.
                       MEMBER POWERS:  If I wanted to get those
           documents, could I?
                       MR. NOWLEN:  Alan Rubin?
                       MR. RUBIN:  Yes, you can, in ADAMS.
                       Pardon me.  That --
                       MEMBER POWERS:  The question was quite
           different and quite explicit.  I asked if I could get
           those documents.
                       MR. RUBIN:  Yes.  They are publicly
                       MEMBER POWERS:  It would be interesting to
           see the one for Waterford.
                       CHAIRMAN APOSTOLAKIS:  Steve, would you
           say that detection and suppression are areas that were
           not modeled very well?
                       MR. NOWLEN:  There was a range of
           treatment there.  Again, you know, some people did
           very well.  Some people took a shortcut.  For example,
           a lot of the submittals used severity factors in lieu
           of detection suppression analysis.
                       CHAIRMAN APOSTOLAKIS:  Or just the
           probability that comes from questionable sources. 
           Somehow this area never received serious -- as serious
           an analysis as the growth factor.  Is it because there
           are things -- the detectors are so reliable that we
           don't even worry about them?
                       MR. NOWLEN:  Oh, no.  No.  I don't think
           that was the case.  It was simply that this was a
           common area where a simplified approach was used --
           again, severity factors.
                       For those who did do a more traditional
           detection suppression analysis, it was typically based
           on the fire PRA implementation guide -- again, had
           developed a series of probability of suppression
           versus time for different classes of fire.  The
           alternative approach was basing the analysis on fire
           brigade response times.  
                       They say, "We can get to -- we've done
           drills.  We can get to this area within 10 minutes." 
           We're going to assume that the probability that a fire
           lasts longer than that is very low.  In some cases,
           they said, "No fires will last more than 10 minutes,"
           and we would typically say, "Please go back and
           reconsider the possibility of a long duration fire."
                       But, again, there is a very wide range. 
           There are some very excellent analyses done based on
           fairly traditional PRA approaches, and there are some
           very shortcut approaches based on severity factors,
           and sort of everything in between.
                       Again, we -- in the context of these
           reviews, we wanted to achieve a comfort level that
           they had identified the vulnerabilities, and at least
           were in -- we're identifying the correct areas that
           were dominant contributors.  And in this particular
           case, what you find is you usually don't get to the
           detection suppression analysis until you're already
           dealing with your dominant contributors.
                       So for us as a review team it perhaps was
           a lower priority than some of the other things.  For
           example, screening -- we paid a lot of attention to,
           did they get the right screening results in the first
           place?  And when we got down to actual quantification
           of what survived in the dominant contributors, we
           tended to not focus quite as much on the details of
           exactly what number they were using.
                       How they got there was certainly a
           criteria.  You know, gee, did you guys use a
           reasonable approach?  Does it at least seem reasonable
           to us?  Again, you're typically dealing with the
           dominant areas by that point.
                       MEMBER POWERS:  You use the word
           "reasonable" a lot in this area.  And it's troublesome
           because you don't give me any idea of how your
           reasoning satisfied them.
                       MR. NOWLEN:  It's very difficult to
           quantify the judgment of a panel of individuals
           that --
                       MEMBER POWERS:  Is it consistent with
           experience?  Consistent with databases?  Consistent
           with models?  Those things I understand.  "Reasonable"
           is not a word I understand very well.
                       MR. NOWLEN:  I shall reexamine every use
           of the word.
                       MEMBER POWERS:  And as Dr. Kress has
           pointed out, I'm inherently unreasonable.
                       MR. NOWLEN:  No comment.
                       CHAIRMAN APOSTOLAKIS:  Coming back to the
           screening --
                       MR. NOWLEN:  Yes.
                       CHAIRMAN APOSTOLAKIS:  -- there was no
           need to assume probabilities for the detection and
           suppression screening scenarios?
                       MR. NOWLEN:  They typically did not in
           screening.  Typically, screening was limited to
           likelihood of the fire, likelihood of -- or, I'm
           sorry, likelihood of the fire, conditional core damage
           probability given the postulated damage state of the
                       In a few cases we had people bring in
           additional factors.  For example, we would see
           severity factors apply in a screening analysis that
           did, in effect, bring in a detection suppression
           credit.  But, again, you know, that's that simplified
           approach that I -- I wouldn't really call it detection
           suppression analysis.
                       And, again, we often questioned the
           factors that went into screening.  If we saw too many
           things going into screening, then they weren't willing
           to declare that they were doing detailed analysis.  We
           would often say, "Hey, look guys, you're going into
           the realm of detailed analysis, and we'd like to hear
           more about that" -- was typically our approach to
                       Anything else?  Let's see, how am I doing
           on this slide?
                       I think we've talked about the PRA
           implementation guide.  It was used quite widely by
           licensees by the way.  There were these 17 generic
           RAIs, and ultimately revised guidance was provided to
           resolve those RAIs within the context of the IPEEE. 
           Some of these still remain open in the broader context
           of PRA, but within the context of IPEEE we resolved
                       I think we covered the severity factor
           approach.  Again, widespread use by licensees of
           severities, severity factors.  About half of the
           submittals used them in some form or another.  And
           various factors -- again, the fire PRA implementation
           guide was a common source.
                       We were especially concerned when we saw
           multiple severity factors being applied to the same
           scenario, and those really raised a red flag in our
           mind and we would chase those down, typically got
           responses that would back off on the second and third
           number that were applied and give us a new answer.
                       And, again, in my own view and what we've
           cited in the report is that this severity factor, the
           widespread use, tended to drive the answers towards
           generic CDF estimates as opposed to plant-specific
           estimates.  And so long as you're satisfied that the
           situation is not too far off from the norm, okay.  If
           we get situations where it appeared like you've got
           something unusual here that might warrant further
           review, we would question those.
                       Okay.  Getting close.  
                       MEMBER POWERS:  In the end, coming up with
           an answer -- how do we know when they do the severity
           factors that they're getting a good answer?
                       MR. NOWLEN:  In the broad context, that is
           an extremely difficult question.  In the context of
           the IPEEE, again, we went back to the -- to the team
           having a comfort level that the licensee didn't miss
           a vulnerability, they've got the right dominant areas,
           they've got the right scenarios.  Maybe we don't like
           the number, but, you know, the bigger picture --
                       MEMBER POWERS:  They were developing
           plausibility there.
                       MR. NOWLEN:  I think so, yes, in a sense. 
           We tried not to get overly focused on the final
           numbers, until you got something like 5E-3.  Then, you
           know -- that's an interesting number.
                       MEMBER POWERS:  How about 5E-9?
                       MR. NOWLEN:  Yes, that one was an
           interesting number as well.
                       Okay.  Again, I mentioned that, you know,
           of these issues there are a number that do remain open
           to debate I think in the broader context of PRA, the
           panel fire issues, severity factors.  Barrier
           reliability was another one that I think still -- and
           gets to the issue of the room to room.
                       Firefighting, how we credit firefighting
           is still an open issue.  Effectiveness of fixed
           detection and suppression.  And these are all things
           that are -- insights that are being transferred to the
           research program, so, you know, you've seen other
           presentations on the research program, I'm sure, and
           so you should see a lot of parallelity between this
           list and what's going on in the research program.
                       MEMBER POWERS:  When you say "non-code
           compliant," you're speaking NFPA code for --
                       MR. NOWLEN:  Yes.  Yes.  There was a
           particular question raised in our reviews regarding
           code compliance.  A lot of the nuclear powerplants had
           retrofitted fire protection systems, and in a retrofit
           situation it's sometimes difficult or impossible to
           meet code.  So there are various code non-compliance
           issues that you'll run into.
                       In this particular context, what we
           typically did is we asked the licensee, are your
           systems code compliant?  Yes or no.  We did not, then,
           ask them to go back and, if the answer is no, use some
           other number.  We simply tried to use it as a flag to
           say here are cases where the generic reliability
           values may not be directly applicable because of these
           non-compliance issues.
                       But this is another area where, you know,
           is there a basis for adjusting the numbers? 
           Absolutely not.
                       So we didn't ask the licensees to advance
           the state of the art and give us some alternative
           number.  We simply tried to use it as a flag that
           would flag that for future attention that, gee, there
           are non-compliance issues for a particular plant
           and --
                       MEMBER POWERS:  What other compliances are
           -- non-compliances are --
                       MR. NOWLEN:  Yes.  A lot of them can be
           nits.  Some are not nits.  And we didn't go to that
           level.  For the purposes of the review, again, we --
           we flagged it that the TER typically will say the
           licensee was asked, and they have said no, this might
           be an area for attention in the future if these values
           are used elsewhere, for example.
                       MEMBER POWERS:  Elevations.
                       MR. NOWLEN:  Elevations, yes.  Whether,
           you know, the detectors are 10 feet apart or nine and
           a half feet apart or, you know -- you can get some --
           you have a very minor -- or minor non-compliance
           issues.  In some cases, they are not minor, though. 
           And, again, we didn't try and --
                       MEMBER POWERS:  It's very important.
                       MR. NOWLEN:  It can be, yes.
                       MEMBER POWERS:  But sometimes the non-
           compliance is not very important.
                       MR. NOWLEN:  Exactly.  And we did not --
           without going onsite and inspecting the system, you
           can't make that kind of a judgment.  And so we didn't
           attempt to.  We simply tried to flag them.
                       And, again, how we deal with that in the
           future -- good question.  You know, PRA still has
           challenges here, and that's one.
                       So, conclusions.  In a lot of ways a lot
           of things we thought we know seemed to have been
           confirmed.  You know, again, we're seeing the fire
           CDFs that are coming in on the same order as the
           internal events values.  You can argue how
           conservative some of those numbers are.
                       That's been the wide perception, that --
                       MEMBER POWERS:  We have Appendix R.  We
           end up with a system that, as Nathan will point out to
           me pretty quickly, has not a great deal of redundancy
           in it.  Why wouldn't you think that it would even have
           a higher CDF than --
                       MR. NOWLEN:  This perception is based on
           past PRAs, and past PRAs have gotten that answer. 
           That's where our perception derives -- 1150.  Even the
           early studies that came out of UCLA, Indian Point,
           they have consistently come up with an answer that's
           on the same order as the internal events, and that's
           what we saw here as well.  
                       So, you know, is the answer conservative? 
           Is it not?  Well, all those debates remain.  But, you
           know, again, the IPEEEs are pretty consistent with
           what we've seen in past PRAs in that regard.
                       Again, main control rooms -- they were
           found to be important.  IPEEEs, we've seen that
           before.  Emergency switchgear, the insight regarding
           multiple cable spreading rooms, those are all
           consistent.  And also, plant-specific configuration
           issues having so much to do with the fire risk.  We
           saw that here as well.  
                       There were various things that would make
           an individual plant -- a room in an individual very
           important, whereas other plants you wouldn't expect to
           see that -- the battery/charger rooms.  You wouldn't
           normally expect those to show up generically, but for
           particular plants they turned out to be important. 
           We've seen that in the past as well.
                       MEMBER POWERS:  Your significance
           determination process -- why is it based on generic?
                       MR. NOWLEN:  Well, PRA is based on a lot
           of generic stuff, too.  I mean, we use generic flyer
           frequencies.  We use generic reliability of
           suppression systems.  You know, there's a lot of
           generic things that go into any fire PRA.  So, you
           know, you don't have enough data to get plant-specific
           on every single item.
                       You know, fires happen, but they don't
           happen every day.  So at some level we have to be
           satisfied with that, and, you know, judge the results
                       MEMBER KRESS:  Let me ask you a question
           about your first bullet again.
                       MR. NOWLEN:  Sure.
                       MEMBER KRESS:  I let it get by me before
           I caught it.  The fire CDFs are normally the same as
           the IPE.  That's an average number.  Did you have any
           correlation between if it had a high CDF and IPE
           value, did it also have a high fire?  Or was there any
           correlation between those things?
                       MR. NOWLEN:  This is a slide that I
           skipped because it -- it's hard to figure out what it
           means to us.  But I'll go back and show it, if I can
           find it.
                       MEMBER POWERS:  I'll just comment while
           he's looking.  Tom, I did plot them, and I had a hard
           time coming to that conclusion, that there was a tight
                       MR. NOWLEN:  What you have here is this is
           the ratio of fire to internal events versus fire CDF. 
           So, you know, we have cases where fire was, you know,
           10 times or more.  So you do tend to see that the ones
           with the higher fire CDFs tend to have the higher
           ratios as well.  Exactly what that means -- difficult
           to say.
                       You know, you can come up with a lot of
           explanations for why that might be so.  Maybe there's
           more uniformity in IPE, more variability in fire.  But
           you look across the board, that doesn't seem to be
           borne out.
                       MEMBER KRESS:  That's sure an interesting
           plot, I'll have to admit.
                       MEMBER POWERS:  Take out the top two
           points and the bottom three.  You'll see what the
           problem is.
                       MR. NOWLEN:  Yes, it's largely a shotgun
           blast.  You've got a -- well, there's our 10-8 plant
                       MEMBER KRESS:  Except the BWRs do seem to
           have a correlation.
                       MR. NOWLEN:  Well, they both seem to trend
           a bit.  You know, you can -- you know, the desire to
           draw a straight line through there is almost
           irresistible.  But, again, how do you interpret it?
                       We originally did this as trying to show
           the ratio of internal to fire, and we said, "Well, we
           need to spread it somehow."  Well, let's spread it by
           fire, and this is what we found.  And it -- we've
           scratched our heads ever since, and we've come up with
           at least six explanations for why that might be true.
                       So in the end, we -- this particular plot
           is not in the report, because there are so many
           potential explanations that you can come up with for
           why that might be so, and it -- you know, you could
           make a career of exploring those I think.
                       MEMBER KRESS:  Well, it's probably because
           if you have a high CDF plant, it's vulnerable to
           failures and the fires create the same sort of
                       The point I wanted to make, though, is if
           I were thinking defense in depth, and I had CDFs due
           to fire that were -- you know, if I were trying to
           control my CDF and I had one of these high CDF plants
           that I wanted to control, I'd put a lot more attention
           on the fire, even though it's comparable, because
           there is such a big uncertainty in it, and that's what
           the defense in depth is.  It's supposed to deal with
           uncertainty.  It seems to me like that's --
                       MEMBER POWERS:  Only when you're a
           rationalist.  When you're a structuralist --
                       MEMBER KRESS:  When you're a
           structuralist, you don't care.  Right.
                       MEMBER POWERS:  -- it deals with the fact
           that you're probably wrong about all of these
                       MEMBER KRESS:  Yes.  I just wanted to get
           my defense in depth --
                       MEMBER POWERS:  I mean, but you raise
           another point.  That you have this number that often
           times is comparable, and yet you are putting far more
           attention on each little nit in the operational
           incidences.  And we have -- I mean, this is like
           having one scenario in a CDF that's big.  And the
           question is:  is fire getting its fair --
                       MEMBER KRESS:  Due attention.  That's
           exactly my point.
                       MEMBER POWERS:  And before I'm willing to
           trudge off and do a lot of things on fire, I think I
           want to look a lot harder at these CDF calculational
           techniques, because there's lots of judgmental
           components to it.  
                       I mean, it's a lot of metaphysical things
           that we're never going to be able to compare them
           against them.  I think you want to look at them fairly
           closely before you jump too much on this, but it looks
           like it's worth jumping on.
                       MEMBER KRESS:  Yes.
                       MR. NOWLEN:  Okay.  We -- I'm sorry?
                       MEMBER POWERS:  Fire is the only place in
           the regulations where defense in depth is defined.
                       CHAIRMAN APOSTOLAKIS:  Not anymore.  Well,
           the white paper I guess is not a regulation.
                       MEMBER POWERS:  The white paper is not a
           regulation.  1.174, contrary to what you may think, is
           not a regulation.
                       CHAIRMAN APOSTOLAKIS:  It carries a lot of
           weight, though.
                       MEMBER POWERS:  Only with you.
                       CHAIRMAN APOSTOLAKIS:  In fires you have
           a lot of --
                       MR. NOWLEN:  It's true.  Fire is -- you
           know, as a discipline, fire has treated defense in
           depth for --
                       MEMBER POWERS:  Let's not congratulate
           ourselves too much here.  Fire may well cull out
           defense in depth, and it may have a prescription for
           defense in depth.  It has not been -- fire protection
           has not done as vigorous a job in the area of
           diversity and redundancy.
                       CHAIRMAN APOSTOLAKIS:  That's right.
                       MR. NOWLEN:  Defense in depth is more on
           the phenomenological side.
                       MEMBER POWERS:  It is the classic
           structural approach to defense in depth, which, of
           course, is the appropriate approach to take.
                       MR. NOWLEN:  Okay.  Returning to the
           conclusions, again, I've mentioned we had a few
           surprises.  The turbine hall showing up in as many
           plants as they did show up I think was a bit of a
           surprise.  You know, in the diesel generator battery
           room kinds of areas showing up -- again, those are
           plant-specific features.
                       MEMBER POWERS:  Do you wonder if turbine
           fires show up because people spend a lot of time
           looking at them after things like Narora, and what
                       MR. NOWLEN:  I think there is an element
           of that, sure.  But from a more traditional
           perspective of fire protection, the turbine hall is
           where all of our worst fire hazards are.  So if we're
           going to have bad fires, it's the most likely place to
           have bad fires.  
                       The risk comes in when you combine that
           potential for a bad fire with collocation of important
           equipment and cables.  And that's where these cropped
           up, and I guess we were a bit surprised to see as many
           plants that had that much safety equipment in turbine
           halls.  You normally consider that secondary site
           power generation.  You might have offsite power.
                       But when you start finding emergency
           switchgear and cables routing through the turbine hall
           to get to the reactor building, things like that,
           that's what cropped up here.  And we had -- again, in
           comparison to what had been done in earlier PRAs, you
           don't see those kinds of areas showing up.
                       MEMBER POWERS:  I think that's -- the
           words that you just appended on, why it was a surprise
           to -- they need to appear a little more strongly maybe
           in your executive summary.
                       MR. NOWLEN:  Okay. 
                       MEMBER POWERS:  I mean, it's just
           something -- go back and look and make sure that it's
           really reflecting what you've learned out of this.
                       MR. NOWLEN:  Okay. 
                       MEMBER LEITCH:  Do you know if any of the
           licensee corrective actions included the use of
           synthetic fire retardant lubricants in the turbine
           blue boil system?
                       MR. NOWLEN:  Well, I don't remember seeing
           that in any of the plant improvements.  That's
           something that has happened for other reasons.  You
           know, in a lot of pumps, in fact, we use high fire
           point oils and things like that.  I don't remember
           seeing any cases where that was cited as an
                       MEMBER LEITCH:  I think it's fairly
           commonly used in the electro-hydraulic control system
           but not in --
                       MR. NOWLEN:  Okay.
                       MEMBER LEITCH:  -- the lubricant system,
           that I'm aware of.  I was just --
                       MR. NOWLEN:  I'm not qualified to answer
           that.  I'm afraid I don't know the answer.
                       Let's see.  Again, I've mentioned the
           point that, you know, we did have a lot of debates on
           methodology as a part of the review process.  We've
           resolved those to our satisfaction in the IPEEE
           context, but a number of those still do remain open. 
           And, again, they're being addressed through the other
           research programs.
                       I think overall we have concluded that all
           of the licensees did meet the intent of the IPEEE
           process with regard to fire.  We did have two
           licensees that at some stage of the analysis cited
           that vulnerabilities existed and took actions to
           address those.  And we have most of the licensees
           identifying at least one improvement, and often
           several improvements.  
                       Sixty-four percent of all the submittals
           cited at least one improvement, and I think, again,
           that's a good news story.  
                       And with that, unless there are other
           questions, I'm done.  Thank you very much.
                       CHAIRMAN APOSTOLAKIS:  Okay.  Our next one
           is by Brad Hardin.
                       MEMBER POWERS:  Brad has an easy topic. 
           Everything else, right?
                       MR. HARDIN:  Good afternoon.  I'm Brad
           Hardin, and I'm going to talk to you about high winds,
           floods, and other external events.  Sometimes we refer
           to them as HFO events.  
                       And I'd like to acknowledge the other
           members of our team here, because I didn't do the HFO
           reviews for all of the plants.  Alan assigned each of
           the team members a certain number of plants, and for
           each of those plants that we were assigned the staff
           member did the individual review.  
                       And some of those people are here today. 
           There's Ed Chow and John Ridgely; Art Buslik; and Uril
           Chelia, who is no longer in our area but he did some
           of those I think earlier; John Chen, who is retired;
           and Bob Kornasiewicz, who is retired also, acted as an
           advisor to us in this area.
                       MEMBER POWERS:  Is there cause and effect
                       MR. HARDIN:  Maybe.  And Mike Bohn from
           Sandia also was very helpful in the SRB meetings.
                       MEMBER POWERS:  And he has left the area.
                       MR. HARDIN:  All of the staff people that
           did the HFO reviews were involved in all of the SRB
           meetings as well and prepared RAIs.  We had a number
           of RAIs in this area, maybe not as many as for seismic
           and for fire, but we did have a fair number of them.
                       The areas that I'm going to cover -- and
           I'll try to do this quickly so we have time to do the
           other things as well -- types of events that are
           included in HFO, the type of screening methodologies
           that were used by the licensees, and a summary of
           results, methodologies.  We can break up the results
           into qualitative and quantitative results, talk about
           each of those.  And then plant improvements, which
           there were quite a few of, and so that's an important
           area to talk about, and then conclusions.
                       As Dana said, this area covers just about
           everything that's left I guess.  And that would be
           high winds, including tornadoes, tornado missiles and
           hurricanes, external floods, including intense
           rainfall, flooding from nearby bodies of water, such
           as lakes, the ocean, rivers, including wave run-up and
           postulated dam failures, both upstream and downstream,
           transportation accidents --
                       MEMBER POWERS:  What is a downstream dam
           failure?  Loss of water?  Is that --
                       MR. HARDIN:  Yes.
                       MEMBER POWERS:  Yes.
                       MR. HARDIN:  Yes, that would be more like
           a loss of water in that case.
                       Transportation accidents from highway,
           aircraft, train, and barge.  And then accidents at
           nearby industrial and military facilities.  And then
           one that's kind of close and related to that would be
           there are other types of external events -- some of
           the type of industrial equipment that they might have
           on the plant itself, like nearby pipeline accidents,
           release of hazardous materials from onsite storage,
           like chlorine and various chemicals, hydrogen, fuels,
           effects of temperature extremes, blockage of drains,
           and intakes by debris.
                       MEMBER POWERS:  You say effects of
           temperature extremes.  Does that include the frazzle
           ice kind of phenomena?
                       MR. HARDIN:  I'm sorry, Dana.
                       MEMBER POWERS:  Frazzle ice?
                       MR. HARDIN:  Yes.  Perhaps breakdowns of
           equipment due to low temperatures, but I guess
                       And then any plant-unique hazards,
           anything particular to a plant because of its unique
           design.  I don't think we found many things like that,
           but those were included as well.
                       The licensees were given a number of --
           I'm sorry, I forgot to put one of the viewgraphs up. 
           They had a number of options they could use in
           reviewing HFO.  All of the licensees -- first of all,
           they had to review their plant-specific hazard data
           and the licensing basis for the plant compared to the
           FSAR.  They had to identify any significant changes
           that might have taken place since the operating
           license review.
                       At that point, if they wanted to make a
           comparison of the plant with the 1975 standard review
           plan criteria, if they decided that they could satisfy
           all of those criteria they were pretty much home-free,
           and they could just document that.
                       They had a choice.  In addition to doing
           that, they could also do a PRA, or they could look at
           the hazard frequency for various things like wind
           events or flooding.  And if they determined that that
           was significantly low frequency they would be all
           right also.  
                       And so I think we'll see that there's a
           combination of all of these different approaches that
           were used.  Sometimes plants combined SRP criteria
           review along with some of the quantitative approaches,
           such as the hazard frequency or the PRA.
                       And the PRAs were done with this different
           level.  Some of them were fairly complete PRAs.  Maybe
           they used one that they had in existence already.  In
           other cases, they did a partial PRA just for the
           subject that they were interested in.
                       And this slide indicates the choices that
           were made by most of the licensees.  Many of them,
           most of them, like 80 percent, decided to do the
           qualitative screening approach using a comparison with
           a standard review plan.  About 15 percent performed a
           PRA, which was either a full PRA, partial, might have
           used more conservative bounding parameters or could
           have been best estimate.
                       Less than five percent of the licensees
           chose to use a hazard frequency approach, so that
           wasn't as popular with them.
                       And a summary of the results -- there were
           no vulnerabilities identified.  However, there were
           quite a few improvements made.  So even though they
           didn't identify anything as a vulnerability, they did
           choose to make quite a few changes and improvements to
           their plans.  
                       Most of the submittals did not define what
           constituted a vulnerability.  I think you heard a
           little bit of discussion earlier about
           vulnerabilities, and that in many cases they did not
           define what they were.  They indicated to us that they
           did not find a vulnerability.
                       About half of the plants reviewed -- 34
           submittals -- reported plant improvements.  And in the
           same cases as were reported for seismic and fire, many
           of these were not reported as having been completed
           yet, but they had been identified.  Some of them were
           still being evaluated, and we did not know if they had
           actually completed all of those.
                       MEMBER UHRIG:  These were not required
                       MR. HARDIN:  No.  We did not require any
                       MEMBER UHRIG:  It was their own self-
                       MR. HARDIN:  That's right.
                       Of the 34 submittals, there were a total
           of about 64 improvements.  So, obviously, some of the
           plants made more than one improvement.  And of these
           improvements, they were about half procedural and half
                       MEMBER LEITCH:  I can't find the reference
           here, but I seem to recall reading that Turkey Point
           had more improvements than anyone else.
                       MR. HARDIN:  That's right.
                       MEMBER LEITCH:  Like five.
                       MR. HARDIN:  Yes, that's --
                       MEMBER LEITCH:  Okay.  Yes, okay, there it
           is right there.  And I guess -- does that say that
           they had -- based on their experience with Hurricane
           Andrew they perhaps recognized some things that the
           rest of the industry did not?
                       MEMBER UHRIG:  They also have determined
           that it leaves a lot of things --
                       MEMBER LEITCH:  Yes.  Yes.
                       MR. HARDIN:  I guess that's possible.  I
           don't know. 
                       MEMBER LEITCH:  I mean, it would seem to
           me that -- you know, that they were there, and they
           perhaps have a better understanding of these kinds of
           issues than some of the other ones.  Maybe they got
           religion and the others didn't.  I mean, I just -- I
           just wonder if the kind of things they did are
           applicable to the rest of the industry.
                       MR. HARDIN:  That could be true.  I don't
           remember if there were other plants that made
           reference to Andrew.  I think there might have been. 
           There may have been other plants that referred to
           lessons they learned from that.  I'm not sure.
                       MEMBER POWERS:  So there's been a --
           following Andrew, there was a lot of attempts to
           publicize -- I mean, people were forever making talks
           about what was learned at Turkey Point in connection
           with Hurricane Andrew.  So it's not like it's hidden
           information.  But whether they got religion or not, I
           don't know.
                       Andrew was a big earthquake.  I mean, a
           big hurricane, but it wasn't the biggest that you
           could hypothesize.  And, in fact, what I understand is
           we're headed into periods of time when we'll have
           bigger ones.
                       MEMBER UHRIG:  Andrew was a very unusual
           hurricane because it did not have a storm surge.  It
           had -- most of the damage was wind.  Very, very high
           velocity winds -- 170, 180 miles per hour.
                       MR. HARDIN:  I'm thinking a little bit
           more about your question.  I think my opinion is that
           probably there were not too many plants that might
           have missed opportunities to make similar
           improvements, because a little bit later -- and I'll
           show you what some of those improvements were -- and
           quite a few of the plants did similar things in this
           area for flooding.
                       MEMBER LEITCH:  Okay.
                       MEMBER POWERS:  Do we still require plants
           to shut down if a hurricane is imminent?
                       MR. HARDIN:  I can't answer that.  I don't
                       MR. RUBIN:  Dana, yes, that's correct. 
           That's still part of the procedures for station
                       MEMBER POWERS:  But we have this
           incredible low probability of damage.
                       MR. RUBIN:  This is defense in depth.
                       MEMBER POWERS:  Good man.
                       CHAIRMAN APOSTOLAKIS:  When in doubt --
                       MEMBER POWERS:  But we're not in doubt. 
           We've done the analysis.
                       CHAIRMAN APOSTOLAKIS:  Often wrong but
           never in doubt.
                       MR. HARDIN:  I know that some plants have
           criteria that shut down if a flood level reaches a
           certain -- a certain level to where they don't feel
           they have enough margin anymore.
                       MEMBER POWERS:  Well, I mean, of course
           the difference is that if -- I mean, the situation is
           that if a flood level is very high, or the hurricane
           is imminent, now it's a conditional probability. 
           Whereas these numbers are annual probabilities.
                       MR. HARDIN:  Okay.  Just go through
           quickly on the remainder of this one.  Flooding
           accounted for the largest percentage of improvements
           -- about 50 percent of those.  High winds was next
           with 27 percent.  Transportation or nearby facility
           accidents was about eight percent.  And then other
           external events was about 15 percent.
                       There were some improvements that were
           cited that were of interest to us because they were
           related to HFO areas, but these were done independent
           of the HFO review, the IPEEE review.  And there were
           36 plants that reported that based on their review
           they concluded that there were no improvements
                       MEMBER POWERS:  Let me ask a question
           about questions of timing on these.  We have -- the
           IPEEE was asked for like in '91, some early time.  And
           now -- and in between the two we had a flooding event
           at WMP II.  Was that recognized in this -- in these
                       MR. HARDIN:  I don't recall that it was.
                       MR. RUBIN:  What are you referring to? 
                       MEMBER POWERS:  Where at WMP they had --
           the fire system --
                       MR. RUBIN:  The internal flooding.
                       MEMBER POWERS:  Yes.
                       MR. RUBIN:  That would come under the IPE,
           the internal flooding, rather than -- this is,
           remember, an external flooding assessment.
                       MEMBER POWERS:  Okay.
                       MR. RUBIN:  That's what I thought you were
           referring to.
                       MEMBER POWERS:  Yes.
                       MR. HARDIN:  Some more results.  All of
           the licensees screened out accidents involving
           transportation and nearby facilities, meaning they
           tried to quantify that area.  They concluded that the
           core damage frequency contribution was less than 10-6,
           or else through their standard review plan review they
           screened it out in that way.  
                       And the same thing with plant-unique
           hazards.  Those also turned out to be pretty low on
           the importance.  I don't recall actually that any of
           those were identified.  Most licensees indicated that
           some form of walkdown had been performed during the
           HFO review.  
                       Sometimes it wasn't specifically stated,
           but I think when they indicated that they had followed
           the standard review plan review approach that would
           require that they do a walkdown in conjunction with
           it, so I assume that they did use walkdowns.  And I
           think it's clear from the improvements they made that
           walkdowns are very important to them in this area,
                       None of the 70 submittals determined that
           there were any particular containment performance
           issues that were unique to external events.  Similar
           issues, as with an IPEEE, were the ones that showed up
           in IPEEE.
                       Some examples of plant improvements --
           protection against high winds, there were procedures,
           sheltering plans, protection of diesel generator
           exhaust system from tornadoes.  There were missile
           shields in some cases, strengthening of exhaust stacks
           of a nearby fossil plant to protect against collateral
           damage.  That's an interesting one.
                       Protection against external floods, and,
           again, procedurals, increased inspection of roof
           drains, improved emergency procedures in the event of
           dam failure.
                       MEMBER LEITCH:  That exhaust stack in
           nearby fossil plants, is that Turkey Point, do you
                       MEMBER UHRIG:  Yes.
                       MEMBER LEITCH:  Because I know that --
                       MEMBER UHRIG:  One of the stacks actually
           went down, and the other one was damaged.  I don't
           know whether they took it down to rebuild it or not.
                       MEMBER LEITCH:  I think Waterford has some
           adjacent fossil units, too.  It's an interesting thing
           to see.  I don't know how adjacent is adjacent, but --
                       MEMBER UHRIG:  Well, Turkey Point was
           close enough that it could create problems, not on the
           reactor but on the turbine deck.
                       MEMBER LEITCH:  Yes.
                       MR. HARDIN:  Some more improvement
           examples for external floods.  The addition of
           scuppers in the roof parapet walls to aid drainage and
           reduce roof loading during heavy rainfall.  That was
           probably the most common improvement that was made by
           a number of plants.  
                       It kind of goes along in line with the
           other one of improved -- increased monitoring to make
           sure that debris doesn't clog the drains in the roofs. 
           Upgrading flood-resistant doors.  Improved penetration
           seals between the service and auxiliary buildings was
           done at Salem, and that was very significant for them.
                       They had calculated a contribution to core
           damage about the order of 10-4, and by improving the
           penetration seals they were able to show a reduction
           down to about 10-7.  And the reason for that was, on
           that particular plant, in that area all three
           emergency trains had cables that were not separated,
           and they could all have been flooded and could have
           shut down all of their emergency service.
                       Protection against accidents involving
           transportation or nearby facilities, plant guidelines,
           excluding all flights over plants.  This would be not
           just overflights by commercial companies, but in one
           case I guess company pilots had not been restricted
           before, and so they were given guidelines to prevent
           them from flying over the plant itself.  Prevention of
           barge shipping of explosives in nearby shipping
                       Protection against accidents involving
           transportation or nearby facilities continued. 
           Addition of backup cooling water intake structure to
           protect against barge accidents.  Addition of concrete
           barriers surrounding propane tank near the diesel
           generators to protect against possible vehicle impact.
                       Protection against external events
           included guidance regarding onsite storage and
           transportation of hazardous materials, review of
           control room habitability as affected by onsite
           storage of hazardous materials such as chlorine.  And
           modifications to prevent ice formation on diesel
           generator service water pumps.
                       Some more -- addition of screens on drains
           to prevent foreign material intrusion into safety-
           related equipment spaces.  Modifications to
           ventilation exhaust systems to protect against
           potential combustible gas explosions.  And
           modifications to plant intake structure to prevent
           blockage from debris.
                       Now we go into a summary of quantitative
           results.  We did have some quantitative results for
           the HFO areas.  On the range of the estimates of
           contributions to core damage frequency for high winds
           and tornadoes, they range from about two times 10-7 to
           six times 10-5 per year.  For floods, they range from
           two times 10-8 to about seven times 10-6.  And I
           mentioned before the improvement that Salem had.  
                       Transportation and nearby facility
           accidents -- we didn't have any values reported other
           than that they were all screened out.  They were less
           than the criterion of one times 10-6 per year.  The
           same thing with the plant-unique events.  
                       MEMBER POWERS:  That transportation and
           nearby facility accidents -- that just reflects the
           fact that that's something that's covered by a
           standard review plan, gets examined in fair detail?
                       MR. HARDIN:  I would think so.  I can't
           remember.  Volume 2 lists a summary of each of the
           areas of review for HFO and whether there was a PRA
           done.  And I don't recall if any of the plants
           actually calculated something.  I think you're
           probably right.
                       MEMBER POWERS:  I mean, we've just
           basically put out a revised standard review plan in
           regard to this stuff.  People look at it fairly
                       MR. HARDIN:  I think you're probably right
           on that.
                       Some more external event quantitative
           results.  Haddam Neck reported for lightning about
           eight times 10-6 per year.
                       MEMBER POWERS:  It says that in the
           document, and it doesn't come back and say, "And other
           people reported much lower values for lightning."  Is
           it the case that only Haddam Neck looked at lightning
           or --
                       MR. HARDIN:  I think there were other
           people that used PRAs to look at this, and they got
           values that were much lower than that.  Haddam Neck
           had the highest values, and that's why we're reporting
                       MEMBER UHRIG:  That area is not the
           highest incidence of lightning in the country.  It's
           much more severe in southwestern Florida.
                       MR. HARDIN:  Yes.
                       VICE CHAIRMAN BONACA:  Some people have
           evaluated it.
                       MEMBER POWERS:  Well, they do evaluate it
           through these peculiarities of how you do the
           probabilistics.  They draw an area, and say, okay,
           well, the frequency of the lightning strikes is so
           much here, so the chance of hitting this little tiny
           vulnerable component that happens to be a spike on the
           top of the loop is --
                       MEMBER KRESS:  Is the ratio of the areas.
                       MEMBER POWERS:  -- is the ratio of the
           areas instead of --
                       MEMBER KRESS:  Strange thing.
                       MEMBER POWERS:  The probabilistics are
           often very strange.
                       VICE CHAIRMAN BONACA:  I know something
           about the snow, for example.  You know, that was just
           simply discovered in that -- the roof of the building,
           the auxiliary building that contains a lot of
           safeguards, too, is designed to sustain as much as six
           inches of snow.  I mean, it's a tin roof.  
                       Yes.  So that procedures to clear the roof
           -- fortunately, of course, we have a high temperature
           inside that building.  That will keep the area melted
           to some degree.  But if you get to low enough
           temperatures you have accumulation of ice.
                       So, I mean, there was, you know, insight
           there that leads you then to have some procedures to
           clear the roof to make sure you are aware of that. 
           So, but --
                       MR. HARDIN:  I think, unfortunately, we
           really don't have much reported information on
           lightning from the plants.  Haddam Neck reported it. 
           There were other plants that reported that they used
           a PRA to do the HFO review, but they didn't tell us
           specifically for the different areas.  So we just
           don't have information on it.
                       And South Texas reported about eight times
           10-6 per year for chemical release.  And, again, I
           think there were other plants that reported chemical
           releases, but that was the largest one.
                       MEMBER KRESS:  Is that close to the oil
           refinery or what?
                       MR. HARDIN:  I'm sorry?
                       MEMBER KRESS:  Is that an oil refinery or
           close to --
                       MR. HARDIN:  I kind of think so down
           there, but I don't recall what the specific facility
                       MEMBER KRESS:  It's being expanded in
           South Texas.
                       MR. HARDIN:  I'm not going to --
                       CHAIRMAN APOSTOLAKIS:  We have a whole
           presentation on unresolved safety issues.
                       MR. HARDIN:  Yes.  So I'm just flashing
           this up here.  This is just to indicate that in the
           HFO area there are some generic issues that had to do
           with these topics.  And John Ridgely will go into
           those in more depth.
                       Conclusions -- there were no HFO-related
           vulnerabilities.  About 50 percent of the plants made
           HFO-related improvements.  And relative to the other
           external event challenges, HFO contributed
           significantly less to overall plant core damage
                       Based on the extent of the documentation
           by the licensees, and the discussions that they gave
           us on this area, it would seem that they actually had
           done quite a bit of work, and they probably learned
           quite a bit about their individual plants, so that
           hopefully if they were to have an event like this they
           would be better prepared to take care of it.
                       MEMBER POWERS:  It really is the
           overwhelming sense that you get in that section, that
           they did a lot more than I would have thought they
           would have done.
                       MR. HARDIN:  There was quite a bit of
           material submitted to us.  I think it did leave you
           feeling that they had done a fair amount of work
           there, and they responded to a number of RAIs in that
           area, and there were quite a few improvements,
           obviously, that they made.
                       MEMBER POWERS:  Good.
                       MR. HARDIN:  These next slides I don't
           think you need to see them unless you want.  Just as
           an example of what they were, this was just to show
           you what some of the quantitative results were, so --
                       CHAIRMAN APOSTOLAKIS:  We should reserve
           some time for the next speaker, I think.  Any other
           questions for this particular -- on this particular
                       Thank you, Brad.
                       MR. HARDIN:  Thank you.
                       CHAIRMAN APOSTOLAKIS:  What time do the
           members disappear?
                       MEMBER POWERS:  4:00.
                       CHAIRMAN APOSTOLAKIS:  Okay.  Tom?
                       MEMBER KRESS:  4:00.
                       CHAIRMAN APOSTOLAKIS:  So it looks like at
           4:00 we should -- well, we still -- we will take a 10-
           minute break.  So we'll start at 3:00.
                                   (Whereupon, the proceedings in the
                       foregoing matter went off the record at
                       2:50 p.m. and went back on the record at
                       3:00 p.m.)
                       CHAIRMAN APOSTOLAKIS:  Back in session.
                       Now, you are threatening us with 47
           viewgraphs here.
                       MR. RIDGELY:  Not actually.  I've added
                       VICE CHAIRMAN BONACA:  Originally, he had
                       CHAIRMAN APOSTOLAKIS:  Before we adjourn,
           I would like to go around the table and get the
           members' views regarding, first, whether we want to
           write a letter, and, second, general comments.  So we
           don't even have an hour for this subject.
                       MR. RIDGELY:  Right.  Which is why I'm not
           going to focus on what the issues are, because these
           issues have been discussed with the ACRS previously.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. RIDGELY:  And so there is no
           discussion of that.  It's only on the materials
           presented.  And I guess I should apologize.  My name
           is John Ridgely, for the recorder.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MR. RIDGELY:  And I do hope to go rapidly
           through this.  But I do hope to get to your questions
           also on there.
                       CHAIRMAN APOSTOLAKIS:  Okay.  You have
           half an hour.
                       MR. RIDGELY:  All right.  This is what I
           propose to do -- list the issues, talk at them --
           about them one at a time, talk a little bit about the
           review process, provide a summary of each of the
           issues with a description -- short description,
           findings, related improvements -- and then come up
           with conclusions.
                       The licensees were explicitly requested to
           address these particular issues -- USI A-45, Generic
           Issue 103, 131, and 57, and the Sandia fire risk
           scoping study issues.  They were not explicitly
           requested to look at these issues -- GSI-147, 148,
           156, and 172.  
                       However, during the IPEEE process it was
           concluded that if the licensees had made an adequate
           submittal that we could also most likely resolve some
           of these issues.
                       The importance of this slide is to show
           that what we have here is an interrelationship between
           not only the issues -- multiple issues -- but they
           appear across also multiple generic issues.  So these
           are very highly interrelated.
                       On the review process, the licensees'
           IPEEE hopefully is complete with regard to these
           issues.  The licensees' assessment was to demonstrate
           an indepth knowledge of the external events as they
           related to these generic issues.  And the licensees'
           assessments results are reasonable, given the design,
           location, features, and operating history of the
                       An issue is, thus, considered resolved if
           no potential vulnerabilities associated with its
           related concerns were identified in the submittal or
           plant-specific improvements to eliminate or reduce the
           significance of the potentially identified
           vulnerabilities were implemented at the plant.
                       Most submittals contained information that
           addressed most of the generic issues.  If information
           on an issue was incomplete, then that was taken up
           with the Senior Review Board and the reviewers to
           determine whether the missing information would lead
           to an important finding or would lead to a potentially
           significant vulnerability that might have been
                       In these cases, requests for additional
           information were sent out to the licensees and we
           proceeded from there.  If not, then the potential
           vulnerability -- if a potential vulnerability was not
           missed, then the SER listed the missing information as
           a weakness.  In such a case, the submittal would still
           meet the intent of the Generic Letter.  And for those
           where the generic issue or sub-issue is not closed,
           the staff will determine separately from the IPEEE
           program if there is any need to do any further work to
           close those particular issues.
                       USI A-45, Shutdown Decay Heat Removal
           Requirements, the objective was to determine if the
           decay heat removal function is adequate, and whether
           cost-effective improvements could be identified.  In
           reviewing the submittals, we found that adequate
           information was provided in the submittals to resolve
           this issue.  
                       The decay heat removal equipment was
           included in seismic and fire PRAs.  The equipment was
           included, and seismic margin analysis in the form of
           a safe shutdown equipment list.  For the seismic
           margin analysis, each component's high confidence of
           low probability of failure value was determined.
                       We've concluded that all plants have
           adequately addressed USI A-45.  All plants have
           identified at least one method of removing decay heat
           and no vulnerabilities were identified.
                       Generic Issue 57 --
                       MEMBER LEITCH:  Can I ask I guess just a
           process question?  If you have concluded that all of
           the plants meet USI A-45, then will ACRS be getting a
           look at that for closure?  Is that the way that's
           going to work?
                       MR. RIDGELY:  I believe this is it.  This
           issue has been brought to the ACRS previously, and the
           ACRS has written letters I think on some of these, and
           they've identified that they're going into the IPEEE
           program for resolution.  Some of them they've dealt
           separately with.
                       MEMBER LEITCH:  Okay.  Okay.  Thanks.
                       MR. RIDGELY:  You're welcome.
                       GSI-57 is the effects of fire protection
           system actuation on safety-related equipment.  They
           were to evaluate the risks that possibly a seismic
           event could induce a fire and induce suppression
           diversion so that you don't have a fire suppression
           system where you need it.  And the other issue is that
           it could actuate the fire protection system and cause
                       In reviewing the submittals, we found that
           the plant's fire protection system was frequently
           designed to the seismic Category II/I criteria.  Most
           plants had the pre-action types which requires two
           independent conditions -- for example, smoke to valve
           and then heat to fail the fuse in the sprinkler head.
                       There were a few that had deluge type,
           which relies then in this case on spatial
           relationships between the fire protection system and
           the safety-related equipment seals and drainage
           systems to keep from flooding.
                       Carbon dioxide Halon systems were reviewed
           for the potential to have adverse effects on personnel
           in the control room and on equipment, predominantly
           there the diesel generator.
                       Our conclusions on this generic issue is
           that the licensees have concluded that the impact of
           this activation is negligibly small, no plant
           vulnerabilities were identified, and all but four
           plants have adequately addressed this issue.
                       CHAIRMAN APOSTOLAKIS:  So that's in a
           generic safety issue as a result -- for specific
           plants.  Is that what --
                       MR. RIDGELY:  For all the plants except
           for four.
                       CHAIRMAN APOSTOLAKIS:  In this case.
                       MR. RIDGELY:  In this case.
                       CHAIRMAN APOSTOLAKIS:  In other cases,
           it's --
                       MR. RIDGELY:  We'll go through each one,
           and I'll tell you what's missing here.
                       Generic Issue 103, the Design for the
           Probable Maximum Precipitation -- in this case the
           objective is to evaluate the potential effects of
           revised PMP criteria on site flooding and roof
           ponding.  Physically, roofs can withstand the
           additional loads because of the excess rainfall
           overflows, the roof parapets.  In some cases, scuppers
           were installed in the parapets.
                       To credit roof drains, licensees referred
           to procedures to periodically inspect for roof
           drainage system blockage.  And typically the site
           flooding from the PMP effects on nearby rivers and
           streams -- this is dam failures, for example -- did
           not adversely affect the plant.
                       If flooding could adversely affect a
           plant, plant changes were usually made -- timely
           shutdown, sand bags, that kind of thing.  Site
           drainage adequately removed very local intensive
           precipitation or there was insignificant water
           accumulation.  Or if there was significant water
           accumulation, no adverse effects on components or the
           components were designed to operate submerged.
                       Confirmatory walkdowns were used to
           identify doors and penetrations vulnerable to moisture
           intrusion, and the ability of drainage systems and the
           site drainage.
                       The conclusion for this generic issue is
           that the original design and construction of the
           plants included sufficient margin to allow for the
           variations of up to two to three times the original
           design basis PMP without adversely impacting safe
           operation of the plant.  No plant vulnerabilities were
                       One plant -- Salem -- installed new
           penetration seals between the service and auxiliary
           water buildings, and reduced the core damage frequency
           from 10-4 to 10-7 per year.  All but three plants
           resolved all aspects of this generic issue.
                       Generic Issue 131 is applicable only to
           Westinghouse plants.
                       VICE CHAIRMAN BONACA:  I have a question
           regarding the statement that you have.
                       MR. RIDGELY:  Yes.
                       VICE CHAIRMAN BONACA:  Those three plants,
           are they committed to resolving those?  Is that --
                       MR. RIDGELY:  There are no commitments
           from anybody to resolve these open issues that I'm
           aware of.  These open issues would now go to some
           other organization -- I believe Generic Issue Branch
           -- and they will determine whether it is worthwhile to
           pursue getting closure on these issues.
                       VICE CHAIRMAN BONACA:  Because, I mean,
           they are not generic anymore.  By the time you go from
           100 plants to three, they're very specific to those
           licensees.  And so I guess it's hard to understand how
           the process works.
                       MEMBER KRESS:  You have to go to a backfit
           analysis, then.
                       VICE CHAIRMAN BONACA:  All right.  I
           understand.  Thank you.
                       MR. RIDGELY:  You're welcome.
                       MEMBER LEITCH:  In a few cases, this table
           in the report that addresses each particular plant and
           whether they have resolved the issue or partially
           resolved the issue, there is a couple of places where
           there are blanks.
                       MR. RIDGELY:  That's because when we were
           in the process of printing this all of the SERs had
           not been written at that time.
                       MEMBER LEITCH:  Okay.
                       MR. RIDGELY:  The next version will have
           them all filled in.
                       MEMBER LEITCH:  Okay.  Thanks.
                       MR. RIDGELY:  This particular issue is
           dealing with a failure of the in-core flux monitoring
           system and in a seismic event with a possibility that
           its movement could cause a small break LOCA.
                       This was applicable to all but three
           Westinghouse plants with those that have an immobile
           flux monitoring cart.  This issue had already been
           resolved by 19 plants, and for six plants the as-found
           condition was adequate.  Adequate restraints were
           added by four plants, and this was mainly installation
           of angle iron welded to the seal table to bolt to the
           transfer table in place.
                       Administrative controls were implemented
           at one plant to restrain a chain from falling onto it,
           and walkdowns were performed to verify the
           installation of previously-installed improvements.
                       Our conclusions on this generic issue is
           that no plant vulnerabilities were identified, and all
           plants have satisfactorily resolved this generic
                       Generic Issue 147, Fire-Induced Alternate
           Shutdown and Control Room Panel Interactions -- this
           issue -- the objective of this is a fire in the main
           control room might lead to a loss of control or power
           to alternate systems before the transfer could take
           place, or the total loss of system function or
           spurious operation leading to a LOCA, and alternate
           shutdown systems needed to be electrically
                       Our finding on this is that many relied,
           in part, on the compliance with Appendix R
           requirements and meeting those regulations.  Alternate
           shutdown locations varied from one place in a plant to
           some -- up to 14 different locations.  And these were
           found to be electrically independent of the control
           room.  No unrecoverable LOCAs would be identified. 
           Spurious hot shorts were considered, anywhere from one
           to six at a time.  And no total loss of system
           function was identified.
                       Our conclusion on this one is that no
           plant vulnerabilities were identified, and 94 percent
           of all of the plants resolved this issue
                       Generic Issue 148 is Smoke Control and
           Manual Fire-Fighting Effectiveness.  The issue here is
           that the buildup of smoke could hamper efforts of the
           fire brigade and operators, potentially damage
           equipment, and lead to misdirected fire suppression,
           or inadvertently initiate fire suppression systems.
                       We found that 65 percent of the manual
           fire -- 65 percent of the submittals credited manual
           fire-fighting actions, 15 percent did not explicitly
           discuss this issue, but it could still be evaluated
           because this issue is related to one of the fire risk
           scoping study issues covering the same topic.  And so
           we could look at that portion of the submittal to
           resolve this issue.  Twenty percent of them took no
           credit for manual fire-fighting activities.
                       While this is a conservative assumption
           from a PRA standpoint, it has its problems.  First of
           all, it does not consider the potential effects of
           misdirected spray.  And if they did not consider this,
           then this is one of the reasons why this issue would
           remain open and not fully closed.
                       Even though they take no credit -- took no
           credit for manual fire-fighting activities, many of
           them did discuss fire brigade training, simulation
           exercises, equipment, and timing aspects.  Because of
           insufficient data to evaluate equipment damage from
           smoke, this aspect of Generic Issue 148 was not
           addressed.  This would be basically beyond current
           state of the art, and that's not what the IPEEEs were
                       Our conclusions were that no plant
           vulnerabilities were identified.  It was completely
           resolved for 71 percent of the plants, partially
           resolved for 25 percent of the plants, and not
           resolved for four percent of the plants.
                       Generic Issue 156 is --
                       CHAIRMAN APOSTOLAKIS:  But you said that
           insufficient data to evaluate equipment damage from
           smoke -- this aspect has not been addressed.  So how
           can you say that it has been resolved for 71 percent
           of the plants?
                       MR. RIDGELY:  For the IPEEEs, their
           challenge was not to advance the state of the art, but
           to use the information and techniques that are
           currently available.  There is very limited experience
           with smoke damage to equipment, and so there really
           isn't any particular basis to derive any kind of a
           conclusion about what smoke would do.
                       Those that did address it said that smoke-
           induced damage to equipment would be a, relatively
           speaking, long-term event, and that that would be
           taken care of by regular maintenance and be something
           that would occur after the fire was put out.
                       CHAIRMAN APOSTOLAKIS:  Yes.  Okay.  I
           won't consider that as resolved, but consider it still
           open until sufficient information is available.  I
           just --
                       MR. RUBIN:  Let me just add to this.  In
           the report itself, in discussing the issues, some of
           the issues are fully resolved by the IPEEE.  The
           plant-specific reviews, some are partially resolved. 
           This issue 148 is partially addressed in the IPEEE
           program.  So that aspect -- this is a discussion I had
           one day with the -- in a subcommittee meeting, just on
           Generic Issue 148 to clarify that point.
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MEMBER UHRIG:  Since the time these were
           written there has been a good deal of work done
           jointly with Sandia and Oak Ridge National Laboratory
           on the damage of fire to particularly the electrical
                       MR. RUBIN:  There are research activities
           going on, particularly with the effect of smoke on
           digital I&C systems, as you're aware of.  And that's
           going on under a separate program.  That's why it was
           not considered to be part of the IPEEE review for that
                       MR. RIDGELY:  The SEP program was to
           review 31 plants that were licensed prior to issuance
           of the 1975 edition of the standard review plan, which
           those plants did not explicitly address the
           information in that SRP.  These are the nine issues
           that are -- were to be addressed, and we will take
           those issues as we go through.
                       Findings on this is that we are -- no
           improvements specifically identified for this generic
           issue were made.  Other improvements were made for
           other reasons that would affect this generic issue. 
           External flooding resolved the hydrological issues. 
           These are issues on the other page of 1, 4, and 6. 
           Seismic evaluation resolved the seismic design issues,
           which would be 5, 7, and 8. 
                       The HFO evaluation would resolve the wind
           and other issues, which is 2, 3, and 4.  And
           resolution of USI A-45 also resolved the shutdown
           issue, which is number 9.
                       Our conclusion is that no plant
           vulnerabilities were identified, and all 31 plants
           have resolved this generic issue.
                       Generic Issue 172 is a Multiple System
           Response Program.  This was to address 11 IPEEE-
           related MSRP concerns raised by the ACRS regarding
           safety issues that might exist and which might not be
           addressed by the NRC's existing generic safety issues. 
           The first one of these is the effects of fire
           suppression system actuation on safety- and non-
           safety-related issues.
                       This issue overlaps Generic Issue 57, and
           it was resolved in part by seismic -- part of the
           seismic walkdowns.  It was also addressed as an impact
           on safe shutdown equipment or safety-related
                       Most of the licensees considered non-
           safety-related equipment unnecessary for safe shutdown
           or drains adequate to prevent unacceptable flooding. 
           This aspect of this issue was resolved for all but two
                       Seismically-induced fire suppression
           system actuation is also addressed by Generic
           Issue 57.  It was addressed in part by the seismic
           walkdown.  Sixty-six submittals evaluated the
           potential effects of inadvertent actuation.  Many did
           not include seismically-induced loss of fire
           protection system.
                       Some included evaluation of the potential
           effects of fire protection system component failures. 
           Plant improvements in this area included replacing
           relays and switches, strengthening component
           anchorages, and implementing procedures to properly
           secure transient fire protection equipment.  This
           aspect of this generic issue was resolved for all but
           three of the plants.
                       Seismically-induced fires is related to
           the Sandia fire risk scoping study, and a few plants
           -- licensees performed PRAs for initiating events. 
           Most addressed the issue as part of the seismic
           walkdown, and most evaluations limited the impact on
           -- to safe shutdown equipment.
                       Some included pipes and tanks containing
           flammable materials.  Plant improvements in this area
           mainly were restraining gas cylinders.  This aspect of
           this generic issue was resolved for all but three
                       The fourth issue is the effects on
           hydrogen line ruptures.  Hydrogen line ruptures did
           not contribute significantly to the core damage
           frequency.  Typically, addressed with walkdowns
           following EPRI's FIVE methodology.  This was resolved
           for all but five plants, but two licensees addressed
           hydrogen lines but not tanks.  The other three did not
           address either of the issues.
                       The fifth aspect of this generic issue is
           non-safety-related control system and safety-related
           protection system dependencies.  This is related to
           the Generic Issue 147 and a fire risk scoping study
           issue.  Safe shutdown can be performed at the main
           control room or the auxiliary shutdown panels with
           only safety-related equipment.  Non-safety-related
           equipment failures would not inhibit shutdown.  This
           was the position that was taken by most licensees.
                       All but four licensees provided adequate
           information to close this issue.  One did not address
           hot shorts, and three did not discuss the issue at
                       The next aspect of this issue is the
           aspect of flooding or moisture intrusion on non-safety
           and safety-related equipment.  The HFO portion of the
           IPEEE resolves the flooding aspect for these
           components.  Moisture intrusion is evaluating the
           potential effects of seismically-induced
           failure/activation of fire protection system and
           misdirected spray from manual firefighting activities. 
           This was resolved for all but three plants.
                       The next issue is seismically-induced
           spatial and functional interactions.  This was
           addressed by -- in part by seismic walkdown.  Most
           submittals limited this to direct impact on safe
           shutdown equipment.  Plant improvements related to
           this were strengthening of component anchorages,
           anchoring cabinets together, procedures to secure
           transient fire protection equipment.  This aspect was
           resolved for all but two of the plants.
                       The eighth issue is seismically-induced
           flooding.  A few licensees evaluated this using a PRA. 
           Most used a seismic walkdown.  Most evaluations
           limited their scope to safe shutdown equipment.  Plant
           improvements in this area include adding seals to
           waterproof electrical cabinets, enhanced drain
           inspection procedures.  This was resolved for all but
           six of the plants.
                       The ninth issue is related to seismically-
           induced relay chatter.  A few plants had low
           ruggedness relays in the IPEEE success paths that were
           not redundant to those in the USI A-46 evaluation. 
           Twenty-seven licensees performed seismic PRAs. 
           Fourteen included relays in their PRA.  Recovery
           actions were not modeled.  Forty-two licensees
           performed separate evaluations.
                       Low ruggedness relays found in alarm
           circuitry, negligible consequences, or operators could
           provide effective reset for those relays.  In a few
           cases there was a plant improvement, and the
           improvement was replacement of the low ruggedness
           relays.  All licensees resolved this issue.
                       Now, item 10.
                       CHAIRMAN APOSTOLAKIS:  Yes.
                       MR. RIDGELY:  I was wondering if you were
           going to get back in time for this.
                       CHAIRMAN APOSTOLAKIS:  I made sure I did.
                       MR. RIDGELY:  The IPEEE issue focused on
           human errors involving operator recovery following the
           occurrence of an external event, namely fire and
           earthquake.  Errors modeled in PRAs were done by using
           the IPE model, modifying the IPE model using
           judgmental scaling factors, or simplified operator
           error fragilities.
                       In seismic margin analysis, reliance is
           placed on most familiar success paths and most
           reliable equipment and qualitative discussion on
           operator reliability.
                       In fire evaluations, the licensees used
           the IPE model or the IPE model with a performance
           shaping factor, expert judgment to determine a factor
           for each action, a conservative screening factor of,
           for example, .1, or some reevaluated or requantified
           all error rates.  And this we consider resolved for
           all but eight plants.
                       Now, for two slides you do not have.  The
           question was asked as to what is the -- give us some
           examples of what was done for plants that -- where we
           found these acceptable.  Well, one -- and I just
           grabbed some off the shelf.  Okay?  These --
                       CHAIRMAN APOSTOLAKIS:  So it's a random
                       MR. RIDGELY:  More or less random example,
                       One plant went back and relied on NUREG-
           4826, the screening approach for a single train and
           multi-train system.  This approach was found
           acceptable and identified so in NUREG-1407.
                       Another plant for the fire -- the human
           error probabilities were increased by roughly a factor
           of 10 over the IPE values, but no credit was taken in
           any sequence for recovery actions, and this included
           the restoration of the loss of offsite power.  In the
           -- excuse me, that was the seismic area.
                       In the fire area for this particular
           plant, only one recovery action was credited, and that
           was aligning alternate power to the reactor protection
           system motor generator sets.  Another plant -- they
           used the IPE human error probabilities until they got
           to a ground acceleration of .5 g.  And then they set
           the error rate to one.
                       They did a sensitivity and --
                       CHAIRMAN APOSTOLAKIS:  At .5 g, it becomes
           one?  Really?
                       MR. RIDGELY:  Yes.
                       MEMBER POWERS:  You wouldn't agree with
           that number?
                       CHAIRMAN APOSTOLAKIS:  Sensitivity
           performance to --
                       MR. RIDGELY:  Right, to .35 g, and this
           changed the core damage frequency by about 50 percent.
                       CHAIRMAN APOSTOLAKIS:  Mean perform
           sensitivity -- that means it was an error of
           probability of one down to .35 g?  Is that what that
                       MR. RIDGELY:  When they changed that to
           .35 g, that's when it crossed over and made it one. 
           They are failure rates.
                       CHAIRMAN APOSTOLAKIS:  Right.  But then
           sensitivity performed to .35 g, what does that mean? 
           That you put the error equal to one at .35 g?
                       MR. RIDGELY:  What they did was they had
           a -- they used -- the IPE value, whatever the error
           rate was --
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MR. RIDGELY:  -- okay, up until they had
           an earthquake magnitude of .5 g.
                       CHAIRMAN APOSTOLAKIS:  Correct.
                       MR. RIDGELY:  Okay.  Then they set it to
           one.  Okay?  Now, then they did a core damage
           frequency probability for this.  All right?  
                       Then there's a sensitivity.  Instead of
           changing the error rate to one at .5 --
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MR. RIDGELY:  -- they change it to .35. 
           And then they -- that changed the core damage
           frequency by about 50 percent.
                       CHAIRMAN APOSTOLAKIS:  Fifty percent from
                       MR. RIDGELY:  From what it was when they
           did this evaluation.  So it's not even a factor of two
           increase in core damage frequency, so it's not
           necessarily -- percentage-wise, it's not a big change. 
           Now, that's what they did.
                       And as far as fire --
                       CHAIRMAN APOSTOLAKIS:  Well, the real
           issue, though, is that the HEPs, it's not just the
           factors that were multiplied here, but it's also that
           they themselves -- it's basic human error
           probabilities.  The ideas are of questionable
                       MR. RIDGELY:  I won't argue with that.  It
           was intended that for the external events that
           hopefully the licensees would look at whatever values
           they start with, usually from the IPE, and say, "Well,
           under those circumstances I could expect the error
           rate maybe to be something higher based upon the
           ground moving or smoke coming in," or whatever.
                       MEMBER POWERS:  I think you're wrong,
           Mario.  We shouldn't put the operators and run a
           scenario with them on the shaker table.  We should put
           the PRA analysts on the shaker table.
                       See if they think that a .35 g would --
                       VICE CHAIRMAN BONACA:  But they would --
           even .35 g seems to be a little bit incredible.
                       MR. RUBIN:  But then, as you pointed out,
           they have time after the .5 g has settled down to get
           up and recover, maybe an hour or two --
                       -- take some operator actions.
                       CHAIRMAN APOSTOLAKIS:  The problem is we
           are dealing with a basic set of numbers that are not
           based on -- don't have a strong technical basis, and
           we will --
                       MEMBER POWERS:  Well, unless they come
           from THERP, and then they are totally reliable.
                       CHAIRMAN APOSTOLAKIS:  Yes.
                       MR. RIDGELY:  You were looking for
           examples where you found that they were not resolved. 
           Well, here we have some here.  The first one --
           modifications to operator actions from an IPE were
           made from a fire, but they did not discuss what the
           effect would be of a seismic event.  And that was left
           as an open issue.
                       Another case -- in fact, two other cases
           they did apparently a very good discussion of operator
           recovery actions for a seismic event, but very minimal
           for fire aspects.  And then, for a partially resolved
           one, they did -- a detailed human error analysis was
           performed to evaluate operator actions that might be
           necessary for each fire area. 
                       However, the seismic human actions
           discussed were -- the general discussion wasn't
           specific to success paths, so that was a partial
                       The eleventh item on this list is
           evaluation of earthquakes magnitudes greater than safe
           shutdown earthquake.  Well, that's the point of the
           IPEEE.  And having done an acceptable seismic portion
           of it, they solved this problem and all of the people
           have resolved this issue.
                       Therefore, in our conclusions for Generic
           Issue 172 -- is that no plant vulnerabilities were
           identified, and 56 plants have resolved all 11 of the
           MSRP issues. 
                       Now, to try to put this a little bit in
           perspective, this is what it looks like.  This is the
           number of plants versus the number of issues that are
           open.  You see there's one plant that has seven issues
           open, one five, but the majority have thrown those two
           out as outliers.  We've had a pretty good success with
           those on a per plant basis.
                       If you want to look at it by an issue
           basis, these are the issues.  Obviously, common cause
           is the biggest issue here, and this is the -- this is
           how it comes about issue by issue.
                       All right.  Sandia Fire Risk Scoping
           Study.  This is to evaluate risks of five previously
           unaddressed fire risk issues that were identified in
           NUREG-0588.  The first issue is seismic/fire
           interactions.  We've heard a little bit about this
                       Fires might cause threats to the plant for
           different reasons, for complicating -- causing
           spurious actuation which could complicate operator
           response to the seismic event, cause actuation of fire
           suppression systems inadvertently, or could lead to
           flooding problems, habitability concerns, diversion of
           suppressions, suppressions to non-fire areas rendering
           them not available for the -- where the fire is,
           potential for overdumping of gas suppression, some
           pressurizations of the compartments, spraying
           important plant equipment.
                       I'll talk about the answers on this one. 
           This was resolved partly with a seismic and fire
           walkdown.  The evaluated induced failure and actuation
           of fire protection systems, plants improvements in
           this area, was to ensure existing procedures for
           securing cylinders were followed, and 66 plants
           provided adequate information to resolve this aspect
           of the generic -- this generic issue.
                       The second issue is the adequacy of fire
           barriers.  The fire barrier issue is important because
           it -- we're talking about protecting redundant
           equipment, potential for fire from one room to go to
           another room, also for retention of smoke.  And what
           we found when we reviewed this is that this discussion
           -- the licensees discussed inspection, surveillance,
           and maintenance procedures for seals and doors, fire
           watches for welding activities.
                       Where they did multi-zone fires they found
           it was not a significant contributor to the core
           damage frequency, and smoke through the penetrations
           they found would be diluted and not inhibit
           firefighting activities.
                       MEMBER POWERS:  Now, you say this is not
           a significant contributor, but we still have this 30
           percent number.  Thirty percent of CDF is not a non-
           trivial number.
                       MR. RIDGELY:  Okay.
                       MR. NOWLEN:  This is Steve Nowlen again. 
           We discussed that -- you know, the idea that 30
           percent of a small number is not significant in this
           context.  For that plant to -- it's a visible
           contributor given their number, but --
                       MEMBER POWERS:  I mean, you're the one
           that's telling me that it's 30 percent of a small
           number.  I know it to be 30 percent of a number that
           can range from one times 10-4 down to 10-8.
                       MR. NOWLEN:  We will be sure to clarify 30
           percent of which number as we do the revision of the
                       MR. RIDGELY:  And 66 of the plants
           resolved this aspect of the fire risk scoping study
                       The third one is smoke control and manual
           firefighting.  This issue became Generic Issue 148. 
           Most submittals discussed consideration of smoke in
           their fire brigade training, and 55 licensees provided
           adequate information to resolve this issue.  This
           issue, again, is for the possibility of hampering
           firefighting activities.
                       The fourth issue is dealing with equipment
           survivability.  Again, this is potential for
           misdirected sprays, for sprays coming on spuriously
           and failing equipment.  This issue is addressed by
           Generic Issue 57.  And 65 licensees provided adequate
           information to resolve this aspect.
                       The fifth issue is fire-induced alternate
           shutdown/control room panel interactions -- a
           combination of fire-induced failures and spurious
           actuation, with a high probability of random equipment
           failures, were identified as potential contributors to
           fire risk.  This issue became Generic Issue 147. 
                       The transfer control from the control room
           to alternate locations is in all the plants.  The
           plants identified they were electrically independent,
           either from the power source or a fuse or breakers in
           the line.  Spurious actuations were considered, and 67
           licensees provided adequate information to resolve
           this issue.
                       Let's see.  So our conclusion is 25
           licensees used EPRI's FIVE methodology.  No plant
           vulnerabilities were identified, and 53 licensees
           resolved all aspects of this generic issue. 
           Graphically, this is the issue.  This is how it looks.
                       Obviously, the one that spans out is the
           -- the LOCA effects, and this is primarily because,
           again, if we're talking about misdirected spray the
           common thing that wasn't considered in manual
           firefighting was not specifically -- not credited in
           20 percent of the plants.  So this is why that
           particular item is so large.
                       Looking at it a different way by number of
           plants, we see that the number of issues -- number of
           plants that have open issues -- again, it's either,
           you know, one or a very low number -- again, defining
           it as a success for closure to this issue.
                       Summary and conclusions.  There were 31
           IPEEE-related issues.  There were unresolved safety
           issues and generic safety issues and sub-issues.  Nine
           were explicitly discussed in the Generic Letter; 22
           were not.  
                       We considered a major achievement to
           resolve a large majority of these issues -- 44
           licensees provided sufficient information to resolve
           all 31 of these issues; 25 submittals had one or more
           generic issues or sub-issues open or partially
                       Saying that a little differently, we have
           100 percent closure on the first three -- A-45,
           Generic Issues 131 and 156; 95 percent on Generic
           Issues 57, 103, and 147; 80 percent on 172 and the
           fire risk scoping study; and 70 percent for 148.
                       For those issues that are not fully
           resolved, potential -- we don't believe the potential
           vulnerability was missed.  They were identified as
           weaknesses in the plant SER.  And any need for
           additional work on those would be addressed separately
           from this program.
                       Saying it a little bit differently, this
           is how it looks, so we consider this to be a success
           of the IPEEE program.  
                       And I'm through all of my slides, and I
           didn't take an hour.
                       CHAIRMAN APOSTOLAKIS:  Thank you.  Thank
                       Alan, you have here some closing
           conclusions and remarks.  I don't know that -- do you
           have anything that's new?
                       MR. RUBIN:  The only thing that's new is
           the examples of the uses of IPEEE information.
                       CHAIRMAN APOSTOLAKIS:  Maybe we could
           address that one.
                       MR. RUBIN:  I think it's useful, because
           I think that --
                       CHAIRMAN APOSTOLAKIS:  Sure.  
                       MR. RUBIN:  I can certainly get through
           this in two minutes.
                       CHAIRMAN APOSTOLAKIS:  Okay.  Good.
                       MR. RUBIN:  Because I think you've heard
           the basic conclusions.  Let me say that we think the
           IPEEE program has met the intent of the Generic
           Letters, and the licensees have met the four
           objectives that I discussed earlier today.
                       But let me put up the slide in this
           package on uses of IPEEE information.  These are
           examples without going into much detail.  First of
           all, licensees have obviously, you've heard about,
           used the IPEEEs to make plant-specific improvements.
                       The second bullet -- the NRC has used
           these issues, as you just heard from John Ridgely, to
           resolve the external event related generic safety
           issues, a large number of them, a very large
           percentage of them.
                       The NRC, and particularly NRR, has used
           the results in the fire protection area to prioritize
           areas for plant inspection.  That's both for the fire
           protection and the seismic areas.  And you've also
           heard in some of the improvements areas licensees have
           used the results to prioritize areas for fire
           protection training in several cases.
                       Another use is that the results have
           provided insights to the risk importance of inspection
           findings.  That has been used in a useful -- in the
           significance determination process for the reactor
           oversight program.  Some of the results from the
           reviews and risk insights have been incorporated into
           NRC's Regulatory Guide, the comprehensive reg. guide
           and fire protection, Reg. Guide 1.189, and the
           industry's fire protection standard, NFPA 805.
                       MEMBER POWERS:  I take it what you're
           saying in connection with NFPA 805 is because NRC
           staff participated in the development of that and had
           some preliminary information on these that that
           somehow got folded in.
                       MR. RUBIN:  That's correct.
                       MEMBER POWERS:  There's no indication that
           having produced this report we're now going back and
           revise NFPA 805?
                       MR. RUBIN:  No.  It's just the insights as
           we went along, and particularly some of the -- you've
           heard the generic questions that we had on the fire
           protection and fire PRA implementation guide were
           carried out and factored into those -- that guidance
                       MR. NOWLEN:  Yes.  If I could elaborate a
           little further.  This is Steve Nowlen again.  The
           three of us who are on the Senior Review Board also
           participated in NFPA 805, so there was, you know,
           direct knowledge of what was going on from the IPEEEs,
           and we communicated that to the panel.  And it did get
           incorporated, so, yes, there is a very -- very direct
                       MR. RUBIN:  And the last bullet on this
           page was that the results of the insights have been
           used to identify topics and to provide a basis to
           prioritize several areas of the fire risk research
           program.  An example is the importance of turbine
           building fires and some other areas that Steve Nowlen
           mentioned in his presentation.
                       One other area we had been asked by the
           Commission -- to look at what is the cumulative effect
           of exemptions to Appendix R on fire risk.  The IPEEE
           was a basis to do that analysis, and a SECY paper was
           provided to the Commission in July 1999.  That was
                       The results were also used to prioritize
           research needs for age-degraded structures and passive
           components using both insights from the IPEEE program
           as well as aging data from operating plants.  And,
           finally, in the evaluation of severe accident
           mitigation alternatives, known as SAMAs, the IPEEE
           results are being used in part for that for the
           license renewal process.
                       So it's a pretty -- I think there are some
           uses that go beyond what we originally anticipated. 
           But as we come to the risk-informed area we're in now
           for many activities these results are more useful than
           I probably would originally have thought when the
           IPEEE program was first undertaken.
                       CHAIRMAN APOSTOLAKIS:  I'd like to go
           around the table, unless there is a specific question
           for Alan.  Thank you very much, Alan.
                       MR. RUBIN:  Okay.
                       CHAIRMAN APOSTOLAKIS:  There are I guess
           at least two questions.  One is, shall we write a
           letter now or wait until the staff has received the
           public comments and responded to them?  Or should we
           write a letter at all?
                       And the second is, what kind of things do
           we want the staff to present at the full committee
           meeting in July?  Okay?
                       So shall we start with the big question. 
           How about the letter?  And then, I would also like to
           know, you know, if we are writing a letter what you
           guys think.
                       MEMBER POWERS:  It seems to me, George,
           we've got to think in terms of two letters.  I think
           in the end we're going to have to write a letter
           explicitly addressing the question of the Generic
           Safety Issues, because we have an obligation in that
           area.  In some cases there are Generic Safety Issues.
                       And I don't think we can write that letter
           closing out the generic safety issues until the staff
           has got public comments back.
                       CHAIRMAN APOSTOLAKIS:  Right.
                       MEMBER POWERS:  Right now, I would say
           that it appears to me that USI A-45, GSI-103, GSI-131,
           GSI-57, all can probably be declared closed, at least
           in a generic sense.  There may be individual plants
           that need something.
                       I don't believe we can conclude that GSI-
           148 and 172 -- that's smoke control and multi-systems
           response -- can be declared closed.  I think we need
           -- I at least need to examine more closely 147 --
           that's shutdown control panel interactions, and GSI-
           146, that is the SEP, a little more to have an answer.
           But I think they will probably be declared closed with
                       CHAIRMAN APOSTOLAKIS:  Okay.
                       MEMBER POWERS:  But, again, closing out
           those issues looks to me like that's a letter to come
           after the public comments have come back and been
           closed.  And in that regard, I think that any
           presentation of the committee has to at least touch on
           a synopsis of what Mr. Ridgely presented to us very
           nicely.  I mean, he's quick, but maybe he's a little
           too quick for the full committee.
                       But the synoptic nature of his
           presentation is quite fine.  Just do more a status
           report on where they stand on those GSIs, but not --
                       MEMBER KRESS:  Save the full presentation
           for later after the public comments.
                       MEMBER POWERS:  Yes.
                       MEMBER KRESS:  So we'll have the --
                       MEMBER POWERS:  Yes.  But I think he -- I
           mean, I think you want to get --
                       MEMBER KRESS:  We need a status report.
                       MEMBER POWERS:  Yes.  I think you need to
           keep the committee abreast on these GSIs, because,
           like I say, in some cases there are GSIs.  So, you
           know, we raised them.  We have an obligation to stay
           abreast of whether they're coming and what not.
                       I think it might be useful for us to write
           an interim letter at this point to the -- in
           connection with this study, if nothing else to help
           the staff highlight it as something that ought to be
           looked at carefully and made public comments on it,
           because there's no question this group of people have
           done a tough, tough, hard job.  
                       I mean, I am quite impressed with what
           they've been able to pull together out of what could
           look like just a cacophony of unrelated results.  And
           I think they've done a really nice job, produced a
           report -- as I call -- refreshingly frank in some of
           its language.  They may want to refine some of that
           language to make sure that it really reflects what
           they intended to say.
                       It may well be that the -- as they say
           that the licensees have fulfilled the objectives of
           the Generic Letter.  I'm not sure that this is
           entirely demonstrable.  And I call attention
           particularly to the simplified fragilities and the
           human reliability analyses that show up in the
                       Another thing I think that it's useful for
           us to point out in a letter is that the -- the IPEEE
           process really has not yielded what I would call
           usable risk information concerning fires and external
           events, usable in the sense of 1.179 determinations,
           and the like.
                       I think it highlights the diversity of the
           technologies available, the lack of standardization,
           the deficiencies of databases that afflict this
           general area simply because it has not received the
           kind of attention that it probably deserves in light
           of the results we're getting.  And I guess that's the
           most overwhelming conclusion we come out of the IPEs.
                       Is the risk so far on the risk of external
           events comparable to normal operating events?  They
           haven't received that kind of technological
           development that normal operating events -- and they
           do highlight areas for priority research.  
                       I think that's going to be one of the
           biggest values, as Mr. Rubin pointed out so nicely,
           that there's a lot to be mined here as far as defining
           what research should be done.  And I think we can
           point -- we could help them highlight the needs that
           have emerged from having done this IPEEE study.
                       Similarly, I think, as you noted, it can
           highlight the challenges we face in the area of human
           reliability analysis and the remarkable absence of
           these topics in the human performance program plan, or
           whatever it's currently called, and what not.
                       But, again, I think we should offer our
           hardiest congratulations to the people involved in
           this work.  I think they put in some substantial
           effort to pull things together as nicely as they have.
                       CHAIRMAN APOSTOLAKIS:  Good.  That's it
           for you.
                       MEMBER POWERS:  That's all I can --
                       CHAIRMAN APOSTOLAKIS:  Any other members
           have anything?  Yes?  Bill or Mario.  Mario, go ahead.
                       VICE CHAIRMAN BONACA:  I just -- I second
           very much the points that Dana has made regarding the
           GSIs and ISIs.  I'm not sure about writing a letter on
           these documents right now before we have -- I would
           rather wait for having the -- you know, the feedback
           from open comments.
                       In general, I also think that this is an
           amazing effort to pull together some insights from all
           of these massive IPEEEs which are a little bit
           obscure.  I would like to make a couple of comments.
                       One is that I think the lessons learned
           from such a large program are somewhat limited, I
           mean, because the expectations of the programs were
           low to start with.  I mean, and so there are two
           lessons there to me.  One is that if you set somewhat
           lower expectations, you get, you know, a hodgepodge of
           information.  It's hard to really get lessons out of
           it.  And it's important -- I find some of the
           conclusions are speculative in my judgment.
                       For example, the one that -- risk for
           older plants and newer plants are similar I think is
           a reach.  I mean, if you walk down most recent plants
           and old plants just it's hard to believe that that's
           true.  And so some of the conclusions are speculative
           somewhat.  I believe, however, that the text puts it
           in that perspective.  It's clear you understand that
           it's a true statement.
                       I also believe that the value to the
           licensees may be somewhat overstated.  I mean, when I
           hear that 36 percent of submittals showed no plant
           improvements, and most of the others had maybe one or
           two, I really wonder -- and, again, it comes from the
           fact that the expectations set by the programs were
           somewhat low, and maybe we didn't get the benefit that
           we could have got if the expectations set were higher,
           like, for example, process and what you would want to
           see out of the program itself.
                       I do believe, again, that given what was
           submitted and developed, I think that this is a good
           summary, this report.  But, again, I would just wait
           for the feedback from the industry before -- or
           comment before I write a letter.
                       CHAIRMAN APOSTOLAKIS:  Bill?
                       MR. RUBIN:  May I take 30 seconds just to
           clarify one point?
                       CHAIRMAN APOSTOLAKIS:  Sure.
                       MR. RUBIN:  I didn't get -- this is a
           slide that I had skipped.  Overall, if you take into
           account the number of plants that made improvements,
           it was 95 percent of the plants made one improvement,
           either fire, seismic, or HFO area.  So the number you
           were quoting was correct for the HFO portion, but --
                       CHAIRMAN APOSTOLAKIS:  Well, I thought it
           was correct also for the fire.
                       MR. RUBIN:  No.  Fire was about 50
           percent, also -- and seismic was 70 percent made
                       MR. NOWLEN:  Individually, each area, but
           when you collect them all together as an IPEEE group,
           you know, you get like 95 percent cited at least one
           improvement across the board.
                       CHAIRMAN APOSTOLAKIS:  Yes, right.
                       VICE CHAIRMAN BONACA:  I understand.  You
           might have an improvement that is a change, and I'm
           saying this is a significant program, and I just -- I
           don't know.  I've been there, and I think that you
           would see much more than that.  That's my judgment. 
           Okay?  And, again, I've been there, and I've seen it,
           and things -- so I am not impressed by the numbers.
                       CHAIRMAN APOSTOLAKIS:  Bill?
                       MEMBER SHACK:  Well, I'm always impressed
           -- you know, I like these integrated programs.  You
           know, we have regulations one piece at a time.  This
           is the one chance to sort of look at the whole impact
           of all the regulations on all the plants at least in
           this area.  
                       And so I think, you know, it's kind of an
           integrated picture that you don't get any other way. 
           So I think it's very important -- you know, I think
           it's -- unlike Mario, I think, you know, it sort of
           made a fairly substantial contribution to managing
           risk.  I mean, I got the impression that the plants
           learned a lot doing this.  You know, they made some
                       I think even the quantification, with all
           of the problems that it has, it certainly gives you at
           least the picture that, you know, this is an area
           where we begin to prioritize, and we begin to put some
           emphasis on it.  So I think that's an important result
           from it.
                       I think the notion of the letter -- I
           don't see why it can't wait until we get the public
           comment.  But I take a much more positive spin on what
           was accomplished in the program.
                       CHAIRMAN APOSTOLAKIS:  Other members? 
           Comments?  Grant?  Yes.
                       MEMBER LEITCH:  I guess my question about
           the improvements is I was left with the impression
           that not all of these improvements have been
           implemented.  And if that is the case, I think some
           kind of a summary on the status of implementation
           would be helpful.
                       MEMBER POWERS:  For the whole committee? 
           Wouldn't that be kind of an arcane thing, for the
           whole committee?
                       CHAIRMAN APOSTOLAKIS:  Well, he'd like to
           see that sometime.  That's I think what you're saying.
                       MR. NOWLEN:  I could comment on that
           because it probably derived from my presentation. 
           That is true.  The status of the improvements is not
           always specified.  In some cases we know that there
           were things that were under consideration, and by now
           may or may not have been implemented.
                       I think beyond what you have in the report
           it's going to be difficult to provide that.  That
           would require a separate followup with the licensees
           to say, you know, "Gee, what did you do about these
           things?"  And right now that's not a part of our
           insights work here.  So it might be something for NRC
           to consider in the future but probably not here.
                       MEMBER LEITCH:  And I think it also -- I
           think also a number of these improvements were made
           independent of the studies.
                       MR. NOWLEN:  Yes.  In some cases, it was
           difficult to be certain whether improvements they were
           citing were being made for other reasons and were
           simply being credited here by -- or whether they truly
           derived from the program.  In some cases, people were
           explicit that, gee, these things we've done before
           really made an impact here, but it was often difficult
           to tell.  So, again, beyond what's in the report
           already, it's -- you can't say much more.
                       VICE CHAIRMAN BONACA:  I would like to say
           one thing.  I think I gave a message that has been
           interpreted as overly negative, and I really didn't
           intend to do that.  
                       What I was trying to do is to say that in
           my judgment if some of the expectations had been a
           little bit stronger in the definition of the program
           -- for example, the way to conduct it in some respects
           and the expectations for what you would get out of it,
           I think there would have been a much higher payback
           than actually was possible given the definition of the
           program itself.
                       I believe that what has been produced
           meets the requirements and the objectives of the
           program.  I believe that more could have been derived
           by a better-defined program.  I'm criticizing probably
           what was written in the requirement for 10 years ago.
                       MEMBER KRESS:  I think we ought to write
           a letter, and I see no good reason to wait until
           public comments.  I think we can go ahead and write
           the letter now while the subject is hot.  It's going
           to be tough to figure out how to squeeze all of this
           into a couple-hour presentation, but I think now is
           the time to write a letter.  
                       And I think it should be a relatively
           positive letter from the standpoint of the -- of the
           nice job they did.  And I think I agree that it did
           meet most of the -- it did meet the requirements for
           the IPEEE.
                       I think there are lessons that could be
           learned that are in addition to the ones they already
           learned.  Number one, I really like the slide that
           highlighted the research needs with respect to PRAs. 
           And I think that's a good one.
                       But I -- one of the things that struck me
           that we didn't dwell on very much was the fact that
           the plant age in terms of when it was constructing the
           license didn't seem to make a damn bit of difference
           on the bottom line CDF.  That was a surprise to me.
                       I worried for years that here we've got
           plants that are licensed under different requirements,
           and you have to tolerate that.  They require each
           plant to be updated to all of their new requirements
           all the time, and I worried about the older plants
           being under different requirements, might not be the
           right -- not be up to par.
                       Well, this kind of puts -- this puts this
           in terms of external events -- it went against my
           intuition.  I would like to understand it more, and I
           wonder also if it's true for internal events.  That it
           doesn't matter.
                       MEMBER POWERS:  I think I would be more
           excited about the conclusion if some legitimate
           regression analysis had been done that -- you know,
           the similarity in the plots may be reflecting
           compensating errors or compensating differences.  And
           it would be nice to see if you could do something --
                       MEMBER KRESS:  I would like to see more
           done on that.  
                       And the other thing that I was looking for
           and really didn't see was that when you have seismic
           for -- in particular, it bothers me that we think a
           CDF, for example, of equal magnitude to the internal
           events might be acceptable, because I suspect you're
           compromising emergency response at the same time.
                       And this is one set of sequences that it
           has high uncertainty to it, in my mind.  And it
           worries me that we don't feel a little -- I worry more
           about those kind of things, especially when I see it
           of equal magnitude.  So that didn't give me a lot of
           comfort that it was just of equal magnitude.  I would
           like to have seen it much lower.
                       And I don't know -- you know, I don't know
           if -- these are just thoughts.  I don't know if
           they're worth bringing up.  You know, I would have
           expected to see a lot more defense in depth associated
           with things like that.
                       CHAIRMAN APOSTOLAKIS:  No.  But, I mean,
           if you wanted to talk about these sequences, these are
           usually very strong earthquakes.  And the fact that
           perhaps the surrounding communities will not exist
           anymore is also a fact.
                       MEMBER POWERS:  Well --
                       CHAIRMAN APOSTOLAKIS:  I mean, even though
           we regulate on -- I mean, it's a fact that if you go
           to .5 g, there will be nobody to evacuate.
                       MEMBER POWERS:  Well, I'd caution you that
           there is not a surrounding community.  The nearest
           town can't exceed a population of 25,000.  So it's not
           like these plants are out in an empty field.
                       MEMBER KRESS:  Except for one and two
           plants, you're right.  
                       And last but not least, I think it's worth
           pointing out that I don't really think these results
           are highly useful for risk-informing the regulations,
           although there are some things you could -- some
           insights you can draw, but I don't think they're
           highly useful.
                       MEMBER POWERS:  I think the only thing
           they tell you is that to risk inform them we're going
           to have to look farther than just the normal
                       MEMBER KRESS:  I think that's what you
           learned mostly for it.
                       CHAIRMAN APOSTOLAKIS:  Okay.  Graham, you
           didn't have a chance to tell us whether you want a
           letter or not.
                       MEMBER KRESS:  Oh, I'm sorry, Graham.
                       MEMBER LEITCH:  Oh, the letter?  I don't
           see any problem with writing the letter now.  I mean,
           I have no problem with writing the letter now.
                       CHAIRMAN APOSTOLAKIS:  I'd rather have it
           at the end, but -- when is the end of the public
           comment period?
                       MR. RUBIN:  July 31st is the end of the
           public comment period.
                       CHAIRMAN APOSTOLAKIS:  So we will have to
           write it in September, then, if --
                       MEMBER POWERS:  Well, they'll get the
           public comments, and they'll have to resolve it.
                       CHAIRMAN APOSTOLAKIS:  Oh, they have to
           resolve them.
                       MR. RUBIN:  We have to resolve them.
                       MEMBER POWERS:  I mean, if we -- it seems
           to me that if we've got things that we want them to
           take into account when they do the resolution we ought
           to write something.
                       CHAIRMAN APOSTOLAKIS:  Are we then
           commenting just as a public stakeholder planning to
           influence the final report?  Or are we commenting on
           the overall project/program?
                       MEMBER POWERS:  No.  I think we want to
           comment on the -- we want to give them the sort of
           stuff that they might want to address as they go
           looking at it and revising it.
                       CHAIRMAN APOSTOLAKIS:  Well, that's
           certainly one point of view.  And I think that would
           be arguing for writing a letter now.  
                       Okay.  So anything else?  
                       Okay.  Thank you very much, gentlemen.  It
           was a very good effort -- seven presentations.  
                       Thank you, members, for being here, and we
           will see you again in a couple of weeks.
                                   (Whereupon, at 4:04 p.m., the proceedings
                       in the foregoing matter were adjourned.)


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