473rd Advisory Committee on Reactor Safeguards - June 7, 2000

                         UNITED STATES OF AMERICA
                             Two White Flint North, Room T2-B3
                             11545 Rockville Pike
                             Rockville, MD
                             Wednesday, June 7, 2000
               The committee met, pursuant to notice, at 8:30
          DANA A. POWERS, Chairman
          GEORGE APOSTOLAKIS, Vice-Chairman
          JOHN J. BARTON
          MARIO V. BONACA
          THOMAS S. KRESS
          ROBERT L. SEALE
          WILLIAM J. SHACK
          JOHN D. SIEBER
          ROBERT E. UHRIG
          GRAHAM B. WALLIS.                            C O N T E N T S
     ATTACHMENTS                                             PAGE
     Introductory Statement                                    3 
     Agenda                                                    3 
     Briefing to the ACRS on the
     GSI-173A                                                 12 
     Draft Report - Regulatory Effectiveness of the
     SBO Rule                                                 69 
     Final Regulatory Guide 1.183 (DG-1081)                  122 
     Response to SRM on PRA Quality                          154 
     .                         P R O C E E D I N G S
                                                      [8:30 a.m.]
               CHAIRMAN POWERS:  The meeting will come to order. 
     This is the first day of the 473rd meeting of the Advisory
     Committee on Reactor Safeguards. 
               During today's meeting, the Committee will
     consider the following:  Proposed Resolution of Generic
     Safety Issue 173-A, Spent Fuel Storage Pool for Operation
     Facilities.  I'm sure this will prove to be totally non-
     controversial; Regulatory Effectiveness of the Station
     Blackout Rule; Proposed Final Standard Review Plan Section
     and Regulatory Guide Associated with the Revised Source Term
     Rule; and Assessment of the Quality of Probabilistic Risk
               The meeting is being conducted in accordance with
     the provisions of the Federal Advisory Committee Act.  Dr.
     John D. Larkins in the Designated Federal Official for the
     initial portion of the meeting.
               We have received no written statements or requests
     for time to make oral statements from members of the public
     regarding today's session.
               The transcript of portions of the meeting is being
     kept, and it is requested that the speakers use one of the
     microphones, identify themselves, and speak with sufficient
     clarity and volume so they can be readily heard.
               I want to begin with a few items of current
     interest.  First, members will notice in their package that
     Mr. McGaffigan has been reappointed to the Commission.
               And members will also notice that Oconee got its
     license extension.  However, there is one item of interest
     that is of special importance to this Committee, and that is
     the NRC has seen fit to award Mr. Theron Brown a Meritorious
     Service Award, so I think he deserves a round of applause
     for this.
               CHAIRMAN POWERS:  This is a well-deserved award,
     and we have benefitted greatly from this.  
               Are there any items that members want to raise
     before we begin the scheduled proceedings?
               [No response.]
               CHAIRMAN POWERS:  If not, we'll turn to the first
     item of business, which is the spent fuel storage pool for
     operating facilities, and Dr. Kress, I think you are taking
     the lead on this?
               DR. KRESS:  Yes, this is Generic Safety Issue 173-
     A.  It's been with us awhile.  
               The issues are the potential to either lose
     inventory out of the spent fuel pool due to some sort of
     leak, may be driven by seismic or otherwise, or to lose
     cooling to the pool so that eventually it heats up, and
     boils off.
               This is for operating reactors, and recently we
     had a similar condition we were looking at for
     decommissioning plants.  Basically, the issues are the same,
     only with operating plants, the pools is there all the time
     and the heat load may even be greater, because it's
     decreasing with the decommissioning plan.
               So the issues are virtually the same, in my mind.  
               There have been events, and in response to some of
     these events, this GSI was initiated, and in 1996, we were
     briefed, the Staff was briefed, briefed us on an action that
     was developed, and the action plan, I think, basically had
     three components:
               One was a plant-specific evaluation or regulatory
     analysis for safety enhancement backfits.  They determined
     that this was not a compliance issue.  It was a safety
     enhancement issue.
               Then they were going to implement rulemaking as
     part of the shutdown rule to deal with this particular
     issue.  And then they were going to revise the Staff
     Guidance.  That's the Standard Review Plan, Regulatory Guide
               What we have is SRP and the Reg Guide to look at. 
     When we reviewed this in 1996, I went back and dug out our
     letters and looked at them.  Apparently there were no
     identified outstanding technical issues at that time.
               And the staff did not ask for us a letter at that
     time, so we didn't produce one.
               We did produce a letter in 1998, which endorsed a
     high priority ranking for this particular GSI.  And
     currently, the Staff is in the process of revising its
     guidance, and I think the intention is to work with the
     industry to revise an ANSI ANS standard and use it.
               I think the objective of the presentations today
     is to see if they could get our endorsement to close the
     issue.  And so with that as a really abbreviated
     introduction, I'll turn it over to George Hubbard, I guess.  
               MR. HUBBARD:  I'm George Hubbard, the Acting
     Branch Chief for Plant Systems Branch.  I think Dr. Kress
     has pretty much summarized the history of where we've been
     on this issue, and what we're looking for today is to get
     your agreement with regard to our proposed action on the
               With that, I'll introduce Chris Gratton, who is in
     the Plant Systems Branch, and he will walk us through some
     of the history and bring us to where we are today and deal
     with that. 
               MR. GRATTON:  Thank you.  Also here today is Tim
     Collins from the Plant Systems Branch.  That was a very good
     lead-in to the situation that we're in right now.  
               We initiated this issue back in 1992, and haven't
     really addressed, other than trying to revise those -- the
     guidance documents that Dr. Kress was talking about, in the
     last two or three years.
               So as we go along through this, the background and
     the history, if there are any questions on where we are or
     what it was that we were attempting to do, please stop, and
     I'll try and clarify what where we're going.
               The purpose of the presentation is to update the
     ACRS on the status of the GSI-173, and to inform you that
     based on the results of the reviews and the evaluations,
     that we intend to close the GSI.
               We do not have any additional actions or
     recommendations, and we intend to seek your concurrence that
     the GSI can be closed.
               As Dr. Kress said, the last time the Staff
     presented to the ACRS on this topic was in August of 1996,
     after completing our review of the technical issues.  
               Since that time, the Staff evaluated certain
     design features to determine whether plant-specific safety
     enhancement backfits could be justified at those plants. 
     The Staff completed that review and published our findings
     in a report dated September 30, 1997.
               At the time, the ACRS did not request a
     presentation on the followup activities for GSI-173-A.  
               Slide 4.  The Staff developed and implemented a
     generic action plan for ensuring the safety of spent fuel
     storage pools in response to two postulated event sequences
     at two separate plants.
               The principal safety concern addressed by the
     action plan involved the potential for sustained loss of
     cooling and the potential for a substantial loss of coolant
     inventory that could expose irradiated fuel.
               The latter concern, Part B to the action plan, was
     previously resolved and will not be discussed here today. 
     The first postulated event sequence was reported to the NRC
     in November of 1992.  
               In the report, it was contended that the design of
     the Susquehanna Station failed to meet regulatory
     requirements with respect to sustained loss of cooling
     function to the spent fuel pool that could result from the
     loss of offsite power or a LOCA.
               The heat and water vapor added to the reactor
     building atmosphere by the subsequent spent fuel pool
     boiling could cause the failure of accident mitigation or
     other safety equipment, and the associated increase in
     consequence -- and have an associated increase in
     consequences from the initiating event.
               Using probabilistic and deterministic methods, the
     Staff evaluated these issues and determined that public
     health and safety were adequately protected for Susquehanna. 
               However, the Staff also concluded that a broader
     evaluation of the potential for this type of event to occur
     at other facilities was justified.
               In addition to reviewing the Susquehanna safety
     issue, the action plan also called for a review of the
     events related to wet storage of spent fuel.  From these
     reviews, the Staff identified areas to evaluate for further
     regulatory actions.
               Design information in support of the evaluation
     was developed through four site visits, reviews of plant
     SERs, and a Staff survey of plant operating procedures and
     designs that was completed in May of 1996.
               The Staff published its findings in a report dated
     July 26th, 1996.  During the development of the action plan,
     the Staff met with the ACRS several times.  
               The Staff received and implemented recommendations
     from the ACRS that aided in the Staff's coming to a
     resolution on these issues.  
               Over the next few slides, I'll discuss the focus
     of the action plan, and the findings and the followup
               Concurrent with the action plan, the Executive
     Director for Operations directed the Office for Analysis and
     Evaluation of Operational Data to perform an independent
     study of the likelihood and consequences of an extended loss
     of spent fuel pool cooling.
               NRR reviewed the AEOD report upon its completion,
     found the results were consistent with the findings from the
     action plan, and modified our action plan to include certain
     insights from the AEOD study.
               DR. KRESS:  That AEOD study, my impression is that
     they really didn't quantify the consequences; they just said
     they were severe or something like that?  
               MR. GRATTON:  I don't know the exact answer to
     that question.  Jose Ibara from AEOD is here and may be able
     to shed more insight on that, on the exact -- 
               MR. IBARA:  Yes, Jose Ibara from Research.  We did
     not quantify it, but we did have data as to how many degrees
     events occurred, and so forth.  It was not quantified.
               DR. KRESS:  Thank you.  
               DR. WALLIS:  I'm not sure now.  You're talking
     about the consequences here?
               MR. GRATTON:  For the AEOD study?
               DR. WALLIS:  The consequences are released to the
     environment of radioactive material.  That was not
               MR. GRATTON:  Not in the AEOD study.  
               DR. WALLIS:  But it was part of your thought
     process?  Somebody must have thought about it.  
               MR. HUBBARD:  This is George Hubbard with the
     Plant Systems Branch.  We did not carry it to the
     consequences.  What we looked at in the Susquehanna study in
     looking at this action plan, we were looking at the low
     probability of these events or the sequences that we looked
     at, and we didn't carry it forward to -- I believe we felt
     the possibilities of these events was low enough that we
     didn't carry it through to the consequences.
               DR. KRESS:  My impression, Graham, is that this is
     like looking at a LERF, where you don't really do the
     consequences, but you have something that's relating to the
               DR. WALLIS:  I'm just asking because your
     transparency says they evaluated the consequences, and it
     appears that they didn't.  So, that's the only reason I'm
     following up on this.  
               MR. GRATTON:  The request from the EDO said the
     likelihood of consequences, but what they actually looked
     into, I don't believe, went into the consequence stage.  
               CHAIRMAN POWERS:  I guess there is the question of
     suppose that I come along and say, gee, the probability of
     an accident is very, very low?  But I'm supposed to be risk-
     informed.  Don't I have to multiply that by the consequences
     before I start taking it off my list?  
               DR. KRESS:  The risk ought to have consequences
     built into it.  The risk is the product of the probability
     of the consequences.
               So you can't say the risk is very low until you do
     the consequence part, in my opinion.  
               DR. WALLIS:  So does that mean that we will not
     know what the risk is today?  
               DR. KRESS:  Well, once again, if you have -- if
     you calculate a LERF for an operating reactor, say, and then
     you basically have a measure of consequences built into your
               I think the appropriate question is what value of
     LERF is an acceptable value?  I think you have a -- you
     don't have a measure of the consequences if you're using a
     LERF that is for one situation, and you're trying to apply
     it to another, I don't think.
               DR. WALLIS:  At least you have an order of
               DR. KRESS:  Yes, it may be conservative and ought
     to be.  
               MR. GRATTON:  To identify the spent fuel storage
     issues and evaluate concerns for identified spent fuel
     storage issues, we focused the evaluation on design features
     and safety functions of the spent fuel storage system.
               Coolant inventory, coolant temperature and fuel
     reactivity were areas evaluated for identifying and
     evaluating spent fuel storage issues.
               Coolant inventory affects the capability to cool
     the stored fuel.  It provides radiation shielding from the
     stored fuel, and mitigates the effects of fuel handing
               We found common design features that reduce the
     potential for loss of coolant inventory.  
               A reinforced, seismically designed structured
     capable of retaining its function following a design basis
     event was found at each facility, welded, leak-tight liners
     with leak detection piping, anti-siphon measures on piping
     entering the pool, and alarms and indications relevant to
     coolant inventory that alert operators to level decreases.
               DR. KRESS:  I'm sorry.  My impression is that you
     looked at every plant?
               MR. GRATTON:  Yes. 
               DR. KRESS:  The design of every plant?
               MR. GRATTON:  Right, exactly.  
               CHAIRMAN POWERS:  That includes Sharon Harris?
               MR. GRATTON:  Yes, it did.  If you remember in the
     beginning of the slides there were four site visits.  They
     were all not visited, but information about the design of
     the spent fuel cooling system was collected on each site.  
               CHAIRMAN POWERS:  I have a letter from Mr.
     Thompson concerning the spent fuel storage facilities at
     Sharon Harris, and it calls attention to some peculiarities
     of that design.  Have you looked at that?  
               MR. GRATTON:  What peculiarities are you referring
     to, in particular?
               CHAIRMAN POWERS:  Availability of makeup water
     supply, the ability to drain the pool down into lower
     regions of the plant and things like that.  He has an
     extensive list of things.  
               DR. BONACA:  Yes, also the use of cooling water
     from the cooling system from one power plant to multiple
     pools, and the original design was intended to have power
     and cooling coming from different units to the different
     pools.  Therefore, you have certainly a higher potential for
     common cause consequences from failures of the cooling
     system or electrical system.
               I mean, I believe that there was a USQ, and in the
     report we received, there was no explanation of how the USQ
     was resolved.  
               MR. HUBBARD:  This is George Hubbard again.  On
     the Sharon Harris, the -- you know, we are aware of it, but
     due to the hearings that are going on, we don't feel that
     it's appropriate to get into a deep discussion, you know, of
     the Sharon Harris situation.  
               DR. KRESS:  In addition, that's just one plant. 
     The other plants don't share these peculiarities, I presume?
               MR. GRATTON:  That's correct that Sharon Harris is
     a unique site.  
               DR. WALLIS:  You mentioned seismic and design
     basis.  Now, there's always a probability of seismic events
     with exceed the design basis and do actually rupture a
     liner.  Does that figure into this?
               MR. GRATTON:  The liner is not the leak-tight or
     the structure that provides the assurance that the inventory
     will remain there.  It protects the concrete behind there.
               The liner is leak-tight, but it is not a design
     feature that maintains the coolant.
               DR. WALLIS:  But to get back to seismic, there is
     a seismic event with some probability which will rupture the
     reinforced concrete.  Does that figure in these
     calculations, or is it just the design basis?
               MR. GRATTON:  It's just the design basis.
               DR. WALLIS:  So this is not really risk-informed
               DR. KRESS:  If you do a risk analysis, you have to
     include the seismic.
               DR. WALLIS:  Yes, you would have to.  But that's
     not included your assessments?
               MR. GRATTON:  No, we did not consider beyond
     design basis seismic events.  From coolant inventory, we
     identified five categories of plants that had design
     features contrary to the design guidance that the Staff
               Four plants lacked passive safety, anti-siphon
     devices on piping that extended below the top of the stored
     fuel.  Five plants had spent fuel pool transfer tubes
     entering the spent fuel pool below the level of the fuel,
     and were not separated from the fuel by a Wier or other
     passive device.  
               Three plants in the category above with the
     transfer tubes have interfacing systems connected to those
     transfer tubes.  These are all at Oconee.  
               Six plants have indirect spent fuel pool level
     indication.  Four plants do not have isolation capabilities
     for liner leak-off systems.
               These were the design features that were
     identified relative to inventory, while we were going
     through and picking up and performing our review of the
     individual plants.
               DR. KRESS:  But these don't constitute compliance
               MR. GRATTON:  Exactly.  These were not compliance
     issues, but they were different from the other plants.  The
     majority of the plants had certain features.  These had
     these unique features.  
               The Staff also concluded that temperature had a
     less direct effort on safe storage of fuel compared with
     inventory.  Coolant temperature was limited by evaporative
     cooling and the rack design ensures a subcooled environment
     surrounding the fuel. As a result, forced cooling of the
     pool is not required to protect cladding integrity when
     adequate level is maintained in the spent fuel pool.
               However, temperature does have an effect on
     structural loads, the purification system operation,
     operator performance and the environment surrounding the
               Normal operation of the spent fuel pool cooling
     system keeps the pool temperature low enough to prevent
     exceeding the acceptance standards.  Short term exposure
     under abnormal conditions to temperatures above 150 degrees,
     which could be experienced during a temporary power outage,
     should not affect the pool structure, the large thermal
     capacity --
               DR. KRESS:  I take it that's Fahrenheit?
               MR. GRATTON:  Yes -- the large thermal capacity.
               While the purification system performs no safety
     related function it does keep the pool's activity low,
     reduces corrosion and keeps the water clear to aid the
     operators during refueling operation.  Coolant temperature
     also affects fuel handling operations.  High temperatures
     result in operator heat stress and can hamper operations by
               DR. WALLIS:  You talked about the temperature of
     the  pool.  You talked about subcooling in the racks.
               How good is the analysis for temperature
     distributions throughout all this pool?  It is not a uniform
               MR. GRATTON:  It is not a uniform temperature but
     they have natural circulation through the pool.
               In the previous analysis we did not actually do a
     thermal hydraulic analysis of the pool as part of this
     study, but what we had found was that the licensees'
     calculations indicated that the region and the rack stayed
     subcooled even under boiling conditions so the racks, which
     are 40 feet below the surface, stayed subcooled.
               DR. WALLIS:  So someone reviewed the licensees'
     analyses and said they were okay?
               MR. GRATTON:  As part of licensing action when you
     do the original design work that is looked at.
               Latent heat and vapor are added to the surrounded
     buildings at very high spent fuel pool temperatures. 
     Subject to the ventilation system, this could affect the
     operability of equipment sharing spaces through condensation
     and operating temperature.  
               This issue was extensively evaluated for
     Susquehanna.  Three features defined this issue --
     multiunits, open paths from the spent fuel pool to the
     safety-related equipment, and a short heatup time.
               The Staff identified seven sites that have this
               Because of a wide variety of cooling system
     designs at operating plants the Staff reviewed the
     capability and reliability of each.  The Staff noticed that
     some reactors lacked the design capability to supply onsite
     power to a system capable of cooling the spent fuel pool. 
     That was identified at seven sites.
               Some spent fuel storage systems have low primary
     cooling capability relative to the potential decay heat load
     in the spent fuel pool. That was at four reactors.
               Some reactors rely on infrequently used backup
     systems to address Loss of Offsite Power Events and
     mechanical failures.  That was at 10 reactor sites.
               DR. KRESS:  Were these judgments made before or
     after the NRC started allowing higher density storage in the
     pool and more fuel in the pool?
               MR. GRATTON:  What decisions are you -- are you
     referring to the allowing of this configuration in the pool?
               DR. KRESS:  Things like the subcooled boiling. 
     Did that include the higher density fuel?
               MR. GRATTON:  That was an original, the way I
     understand it, that was an original concept but every time a
     plant goes through a relicensing --
               DR. KRESS:  -- they have to relook at those
               MR. GRATTON:  That is a reconsideration.
               What I want to do right now is to let you
     understand that we are looking at the -- this is a portion
     of the presentation that has already been given in 1996.  I
     am just sort of recapping what the Staff presented
     previously, so on the previous slide where the coolant
     inventory issues that the Staff identified that looked into
     it and the results of it, these were the coolant temperature
     issues or the areas that the Staff identified when reviewing
     features about coolant temperature.
               On the next slide --
               DR. WALLIS:  Can I ask you about the temperature
     distribution?  Is it all theory or have there been events in
     pools where there have been temperature transients which in
     some way confirm that the analysis was okay or is it all a
     matter of someone looks at theory and says I don't see any
     mistakes, looks reasonable, must be okay?
               MR. GRATTON:  Are you referring to heatup rates or
     the distribution of the --
               DR. WALLIS:  All these questions about subcooled
     boiling and temperature distribution and what happens in a
     transient and how hot does it get.
               MR. GRATTON:  I am not familiar with any
     studies --
               DR. WALLIS:  Was it all theoretical studies or are
     there some evidence from real pools?
               MR. HUBBARD:  This is George Hubbard again.
               In some cases in particular we had one plant that
     came in for a rerack within the last three or four years. 
     We went to Research and had them run some CFD codes to
     determine the heat distribution throughout the pool because
     there were some concerns with the circulation because they
     were putting racks or asking for permission to put racks in
     the cask pit for a period of time and so with NRR and our
     people there and Research folks we ran some CFD calculations
     to determine what is the good distribution.
               From that effort I believe we found not a big
     variation in the temperature from the bulk temperature that
     we consider when we normally do the rerack calculations.  I
     would say it was maybe on the order of 10 or 15 degrees
     difference with that particular analysis that we did there.
               MR. GRATTON:  What George is referring to is
     another analytical type thing.
               Plants have instrumented -- I don't want to
     speculate, but I know plants have instrumented their pools
     and have calculated things like decay heatup rates.  For a
     particular decay heat rate, the pool heatup rates, but off
     the top of my head I do not remember if they have
     instrumented the pool such that they have gotten a
     temperature gradient from the top to the bottom to verify --
               DR. WALLIS:  It just seems to me that when so much
     depends on codes and analysis in all these nuclear plants,
     have we any evidence at all, like some event, that you could
     use to check those?  It would be very useful.
               MR. GRATTON:  I mean other than a loss of cooling
     event where the pool heats up slowly over a couple of hours,
     that would be the only thing that I could think of, off the
     top of my head, where you could go back and use the analysis
     to go back and verify that the system, the natural
     circulation system, is performing properly.
               DR. BONACA:  One interesting point is that
     typically these pools run well below the 150 degrees. I mean
     they run around at least 50 degrees below that, something on
     that order, so it gives some confidence that if you have
     variations there will be --
               DR. KRESS:  That is if your cooling system works.
               DR. BONACA:  Absolutely.  I agree with that.
               I am saying that the design limit of the pool
     under normal conditions is a way from --
               DR. KRESS:  I don't think from a risk perspective
     you worry very much about these temperature distributions
     and subcooled boiling, because all you are doing is possibly
     damaging individual fuel -- what you really worry about is
     if you lose all the inventory and lead this thing into a
     meltdown type situation.
               DR. BONACA:  That's true.
               DR. KRESS:  And that is a completely different
               MR. HUBBARD:  George Hubbard again.  I believe
     relative to AEOD when they took a look at it, and I don't
     remember the numbers right offhand, but they looked at
     events that led to heatup and how frequent that was and if
     you want a little more detail on it, Jose maybe can give us
     the actual numbers, but I think they divided it up on how
     often you had a heatup of 10 degrees or 20 degrees and it
     was very infrequent.  
               Do you have the numbers there, Jose?
               MR. IBARRA:  Yes.  We did look at actual events
     and there were a few but we did look at events in which the
     temperature rose like 20 degrees, and if I remember, that
     occurs only in 3 in 1000 reactor years.
               DR. KRESS:  There is certainly not enough
     information to validate the code.
               MR. GRATTON:  Right.  On Slide 7 it summarizes the
     Staff's review of the fuel reactivity portion of the spent
     fuel pool action plan.
               The Staff reviewed the design of the spent fuel
     pool storage, structures and components which control the
     stored fuel including the use of solid insoluble boron and
     did not identify any issues relative to the spent fuel pool
     reactivity control and therefore did not include any
     followup actions for fuel reactivity.
               DR. KRESS:  But what happens to soluble boron as
     you boil away water?  Does it concentrate or does it go off
     with the steam?
               MR. GRATTON:  No, it concentrates.
               MR. BARTON:  Is there a saturation limit on it
     where it would precipitate out at some --
               CHAIRMAN POWERS:  Isn't there vapor pressure?
               MR. GRATTON:  I don't know.
               CHAIRMAN POWERS:  I mean I think there is a vapor
     pressure for boric acid.
               DR. KRESS:  So it would leave with the vapor?
               CHAIRMAN POWERS:  I don't know.  It may depend on
     the partition.
               DR. KRESS:  Yes, it depends on the partition
               CHAIRMAN POWERS:  Do you know what that is?
               DR. KRESS:  Well, I think at low pressure it is
     such that it would concentrate.  At high pressure it is such
     that it would dilute.  But these are low pressure, so I
     suspect he is right.  It concentrates.
               MR. GRATTON:  At the completion of this portion of
     the review the Staff concluded that existing systems,
     structures and components related to the storage of
     irradiated fuel met the regulations.
               Protection was provided by several layers of
     defense.  The Staff also concluded that because of the
     design and operational factors associated with spent fuel
     pools they constituted only a small fraction of the overall
     risk of operating a nuclear power plant.
               DR. KRESS:  Most of these pools are located
     outside of containment?
               MR. GRATTON:  That's correct.
               DR. KRESS:  Was there any defense-in-depth
     thinking going into this?
               MR. GRATTON:  Let me correct something.  The BWRs
     are in the secondary containment.  Is that what you are
     referring to?  Are you talking about the primary
               DR. KRESS:  I am talking about primary
     containment.  BWRs are in secondary.
               MR. GRATTON:  There was only one that was in
     primary containment, I believe.
               DR. KRESS:  Yes, one of the MARK IIIs, I think,
     would be --
               MR. GRATTON:  Well, I think it was Big Rock Point. 
     Was that the only one that was in containment, George?
               I don't remember.  Go ahead.
               DR. KRESS:  But anyway, I was thinking here's fuel
     that we are talking about some sort of an accident
     condition.  It is basically outside containment.
               MR. GRATTON:  Right.  It is either in the fuel
     handling building or in the secondary containment.
               MR. HUBBARD:  George Hubbard again.  I believe you
     were mentioning did we look at defense-in-depth and that was
     considered with regard to multiple systems for providing
     makeup and that was looked at as part of this, in coming up
     with these conclusions.  We did look at that.
               DR. BONACA:  I have a question on that, because in
     the original report -- he talks about several layers of
     defense and refers specifically to prevention, mitigation
     and radiation protection, and when it talks about prevention
     it specifically states quality control and design,
     construction and operation.
               Now several of the older plants do not have in
     fact a quality requirement imposed on the cooling systems
     and we have reviewed one just recently and it didn't have
     it, so is it that old plants have these quality requirements
     or controls or is it just that you have a few that do not
     have them?
               I mean this is a very generic claim made in the
     front of the report to say it is not a generic concern and
     prevention is identified as purely quality controls.
               MR. GRATTON:  I think the intention of the
     statement was that consistently across all the plants that
     there was a defense-in-depth applied.
               If it was not a quality control like let's say a
     seismically qualified spent fuel pool cooling system that
     they had a seismically qualified pool and seismically
     qualified makeup systems, redundant makeup systems, that
     could provide water to the pool such that evaporative
     cooling would be available to cool the pool in the event
     that a seismic event took the cooling system out, so it is
     very hard to make a general statement about all the pools
     since they are all so different but since we looked at them
     all, I think that this general statement was made in the
     effect that at each -- if you took an individual slide of
     plant there was a defense-in-depth at that plant that was
               DR. BONACA:  I mean one, they were reviewed,
     claimed, and it was accepted that they do not have to
     monitor aging of the system because it's not part of the
     design basis and is not part of quality commitments, so I
     know for one that it is not the only pool out there, so I am
     saying that the statement is general to me and I immediately
     had some examples that don't meet this.
               DR. KRESS:  If you entered into one of these loss
     of cooling or loss of inventory sequences, the response is
     all operator action, I presume?
               MR. GRATTON:  There is no automatic response,
     that's correct.
               DR. KRESS:  And he is told what to do in some sort
     of procedures, operating procedures?
               MR. GRATTON:  Yes.  Notwithstanding the Staff
     reviewed each plant against the criteria in identified areas
     where potential safety enhancements could be investigated.
               Ten design features, five inventory related and
     five related to spent fuel pool decay heat reliability, were
     identified for further evaluation by the Staff to see
     whether safety enhancement backfits could be justified.
               We added an additional design feature to the
     review based on the results of the AEOD study;  48 plants
     had one or more of the design features of concern.
               The Staff also planned other actions as a result
     of the study. Rulemaking, which was previously mentioned,
     was in progress for the shutdown rule at the time and the
     Staff plans to incorporate lessons learned into the review
     guidance documents that the Staff uses to review changes to
     spent fuel storage designs.
               DR. KRESS:  Is that still the plan, to have the
     shutdown include --
               MR. GRATTON:  No.
               DR. KRESS:  No?
               MR. GRATTON:  No, that has been tabled from the
     time that this was originally issued.
               The Staff presented the results of the spent fuel
     pool action plan, which is the previous four, five slides,
     to the Commission and to the ACRS in July and August of
     1996, respectively.  At the time the committee was satisfied
     with the performance of the review and the Staff did not
     feel it was necessary to obtain a closure letter on this
     issue from the ACRS at the time.
               Where we are is that was the spent fuel pool
     action plan -- about 1996 in August.  We  have just finished
     the presentation on the Staff's review, identification and
     review of the spent fuel storage issues.
               From that we identified 11 followup activities
     that in 1997 we went out and evaluated.
               The Staff planned to address the followup issues
     from the spent fuel pool task action plan either by
     performing a regulatory analysis to determine whether a
     safety enhancement could be justified or by gathering
     additional information to augment the information during the
     spent fuel pool task action plan.  
               The Staff determined that seven design criteria
     warranted regulatory analysis.  For the other four issues
     some evaluation was warranted.  This could be an evaluation
     of the administrative controls, the capability to align and
     operate a backup cooling system, or a review of the actual
     design of the component of concern.
               For each of the issues requiring regulatory
     analysis a probabilistic analysis was first performed as a
     screening criteria to determine the likelihood of obtaining
     a given endstate.  The Staff visited seven plants to gather
     information about five of the seven issues requiring a
     regulatory analysis.   With the other two issues the Staff
     addressed the issues either through a voluntary action by
     all of the licensees in that group or by using information
     already available to the Staff here at headquarters.
               Conservative endstates were chosen for these
     evaluations.  One was for the inventory issues an endstate
     of one foot above the top of the fuel was chosen and for the
     loss of decay heat removal eight hours of sustained boiling
     in the spent fuel pool was chosen.
               DR. KRESS:  Why was eight hours decided?  I figure
     that's the amount of time that anybody could recognize what
     is going on and make corrective actions, or something?
               MR. GRATTON:  No.  It really had to do with the
     capability of equipment, the vapor to transport to areas
     where equipment, safety equipment, was located.
               DR. KRESS:  Oh, you were worried about the effect
     of the steam on other equipment?
               MR. GRATTON:  Yes.  It is not the boiling itself,
     it's the shared systems and structures, components of the
     design features, and I believe the eight hours was a
     conclusion in the Susquehanna safety evaluation report.
               Is that correct, George, or Sam, do you remember
     that -- where the eight hours came from?
               MR. LEE:  The eight hours is in addition to about
     14 hours of time that is heatup time already, so we are
     looking at about 22 hours of time starting from the loss.
               MR. GRATTON:  The Staff used the following
     screening criteria with these endstates, which parallels the
     Staff's guidance on regulatory analysis.
               If the frequency that was calculated was less than
     10 to the minus 6 per reactor year, the probability was low
     enough so that a safety enhancement backfit would not be
               If the frequency was greater than one times 10 to
     the minus 5th the Staff would do further evaluation on the
     design feature to determine whether or not a safety
     enhancement backfit was justified.
               Between those two limits, 10 to the minus 6th to
     10 to the minus 5th engineering judgment was used
     considering the available margin to determine whether
     further analysis was justified.
               DR. KRESS:  Now these criteria are basically the
     same as the safety goal screening criteria of regulatory
     analysis?  They are based on it.
               MR. GRATTON:  Right.  We try and base it on it.
               DR. KRESS:  You have to dig it out of that matrix
     but they are basically the same, which brings to mind a
     number of questions --
               MR. GRATTON:  -- that I hope I can answer.
               DR. KRESS:  Okay.  Number one, I presume none of
     these -- the reason you didn't proceed with any of these
     backfits is that none of them passed the screening criteria?
               MR. GRATTON:  Well, as we go through, one group
     did meet this -- I will call it meeting the screening
     criteria if it exceeded 10 to the minus 6th --
               DR. KRESS:  Okay.
               MR. GRATTON:  -- and I will tell you how we
     addressed it on those.  The rest of them, as you will see,
     did not contain a frequency of greater than 10 to the minus
               DR. KRESS:  Now let me see if I can express my
     question in a way that it is understandable.
               The safety goal screening criteria is basically a
     LERF.  It is a CDF and a conditional containment failure
     probability, but if one looks at it properly it is basically
     like a LERF, and the numbers, the values, the limiting
     values or acceptance values or the values that pass the
     screen come out of the prompt fatality safety goal. They are
     derived from it.
               It is like the LERF in 1.174 is derived from the
     prompt fatality safety goal.  That is why it is called a
     safety goal screen.
               Now for a given LERF value, or a given combination
     of CDF and containment failure probability, to meet the
     prompt fatality safety goal it relies on information or
     knowledge about what fission products are released, how many
     and what mix of isotopes there are because those are what
     cause these prompt fatalities, plus it also depends on the
     atmosphere transport things but those can be dealt with.
               But the problem, the question I have, is these
     particular safety goal screening criteria that are part of
     the regulatory analysis are based on the standard source
     term for an operating reactor if an operating reactor
     undergoes a core melt accident.
               Now there is some question as to whether a spent
     fuel pool accident produces the same mix of fission
     products.  The quantities may be more or may be less,
     depending on when and how much fuel is in there, but it is
     the mix of fission products that is of concern to me,
     particularly if the accident leads to the final conclusion,
     which is a higher oxidation of zirconium driven accident.
               The question that this brings to mind is are the
     safety goal screening criteria in the regulatory analysis
     appropriate to use for a spent fuel pool accident, and that
     is the question, and if it is not appropriate, what
     acceptance criteria or what screening criteria should be
               Do you understand my question?
               MR. GRATTON:  I understand it but I am not -- my
     legion of experts over there can also assist me in this
     response, but I am not sure there is a one for one
               The endstates that we chose are not accident
     conditions per se.
               DR. KRESS:  Of course you have got some
     conservatism there in the endstates.
               MR. GRATTON:  We had a large conservatism in both
     of these things, plus the progress of the accident beyond
     that point is really not very well understood or researched.
               DR. KRESS:  But to have an acceptance criteria you
     need to know something about that additional progress and
     you need to know how conservative your endpoints are.
               MR. GRATTON:  What we tried to select were
     endpoints that were conservative enough that we felt if we
     fell in the 10 to the minus 6th range that it was an
     extremely conservative --
               DR. KRESS:  Well, that is the part that bothers me
     because those are intuitive judgments.
               MR. GRATTON:  Right.
               DR. KRESS:  And sometimes we found out in the
     severe accident business that our intuition tells us the
     wrong things.
               I worry about using intuition to determine precise
     acceptance criteria for something like this.
               MR. GRATTON:  Sure.
               DR. KRESS:  And that is the part that bothers me
     about the whole study, I think.
               DR. BONACA:  I had one other questions, by the
     way.  You referred to these probabilistic evaluation or
     analysis but to what extent has there been an evaluation of
     both potential initiators, because we talk about not looking
     at source term because of very unlikely events but I am not
     aware of any thorough, systematic assessment of the
     potential initiators to be considered.
               For example, you are more focusing on certain
     criteria that you have to meet and how unlikely it is, but
     it is also, it seems to me, surmised that it is unlikely to
     get there.
               For example, I would suspect that sabotage wasn't
     considered as a possible initiator.
               MR. GRATTON:  No, it wasn't.
               DR. BONACA:  And just making an example here, and
     typically if you want to have some credible probabilistic
     assessment you would do some systematic assessment of the
     potential initiators and you would find it varies
     significantly from plant to plant, and I don't think that
     was done, was it?
               MR. GRATTON:  Yes, we did.
               DR. BONACA:  You did?
               MR. GRATTON:  For each plant, and Sam can give a
     more detailed answer to this, but for each plant we selected
     lead plants which were representative of the issue for, like
     say for the shared systems and structures issue.
               There were 13 plants in it and I believe they were
     at four or five different sites so obviously they were all
     multiunit sites, but we went in and -- Sam, I will let you
     describe how we described the initiating events and
     evaluated the probability or the frequencies.
               MR. LEE:  This is Sam Lee.  First of all, I would
     just like to make a minor correction for the record -- the
     criteria that we had used was 10 to the minus 5.  I think
     there was a mixup.  It was 10 to the minus 6.
               As far as the initiating events go, there were
     about five initiating events that we looked at, which
     include loss of offsite power, loss of spent fuel pool
     cooling system, and loss of spent fuel pool inventory, and
     we even considered earthquake as well in the analysis, so
     those all factored into the analysis.   
               When we looked at the results, depending on the
     plant, for one specific plant like Hatch the dominant
     initiating event frequency that contributed most to the
     total estimate was from the loss of offsite power sequence
     and second to that was the earthquake initiating event, so
     we did look at it pretty comprehensively.
               DR. WALLIS:  May I ask a much simpler question?
               MR. GRATTON:  Sure.
               DR. WALLIS:  You have all this instrumentation
     here.  Are other people around in this building?  If the
     pool is boiling, is there someone in there to see it is
               MR. GRATTON:  Yes.
               DR. WALLIS:  All the time?
               MR. GRATTON:  Not all the time, but there are
     operators --
               DR. WALLIS:  So every eight hours maybe someone is
     around that's supposed to look?  Maybe that is where the
     eight hours comes from -- every eight hours someone is going
     to be around the building, and if it is boiling it is going
     to be obvious.
               MR. HUBBARD:  This is George Hubbard.  I think
     particularly for an operating plant someone is going to be
     around, particularly in the high heat load situations during
     refueling.  Those situations are going to have people
     definitely there and they are going to recognize it is
     getting awful warm before it ever gets to the boiling state,
     so for the operating plant I think there's going to be
     people there to realize that something is different.
               MR. GRATTON:  I still believe though, and I can't
     find it right now, it's in the Susquehanna SER, that there
     was a concern about how long safety-related equipment could
     last in an environment where the spent fuel pool was
               There was a conclusion made, based on expert
     judgment I believe or whatever the conclusion was, was that
     for boiling of eight hours the safety-related equipment was
     robust enough that they felt it could continue to operate in
     the environment in a pool and adjacent space boiling.  I
     think that is what we used for the basis of it but I can --
     it is in the Susquehanna safety evaluation report.
               So the first group of plants -- I'm sorry?
               DR. KRESS:  How long does it take for a typical
     pool with its loading to uncover the fuel?
               MR. GRATTON:  To uncover the fuel?
               DR. KRESS:  If it went into boiling.
               MR. GRATTON:  A typical pool -- none of them are
     typical but if you use a boiloff rate of 50 gallons per
     minute it takes a significant amount of time for a 400,000
     gallon pool or 350,000 gallon pool to boil off.
               As a rule of thumb there is about 200,000 gallons
     of water above the racks -- above the top of the racks -- on
     a typical pool.
               In the followup actions, in the first group, these
     are the ones that we plan on doing the risk assessment for
     the probabilistic analysis on.  There was another group that
     required additional evaluation when the Staff gathered
     information via the site visits that we went on and we also
     had teleconferences with licensees and reviewed material at
     the NRC to determine the need for further regulatory action.
               DR. KRESS:  You actually didn't proceed to any
     kind of cost benefit analysis?
               MR. GRATTON:  No, we did not.
               DR. KRESS:  Didn't get that far in the
     regulatory --
               MR. GRATTON:  The seven design features -- we'll
     go back to that, number 9.  The seven design features was
     the plant performed probabilistic analysis are the absence
     of passive anti-siphoning devices, the transfer tubes that I
     talked about with Oconee, piping entering the spent fuel
     pool below the fuel -- and this is at the SSF at Oconee has
     piping actually attached to the transfer tube in a
     configuration where the transfer tube isolation valve is
     operated with it open when the plant is operating, limited
     instrumentation for loss of coolant events, the effects of
     adverse environments on the multiunit plants with shared
     systems and structures -- this was the issue that came out
     of the Susquehanna review, the absence of onsite power for
     spent fuel pool cooling systems and limited instrumentation
     for a loss of cooling event.
               These were the issues that we did regulatory
     analysis on.  
               The four design features which the Staff gathered
     additional information on are shown on Slide 10.
               And that is the absence of a liner leak detection
     or isolation system limited to K heat removal capability for
     the systems that supply cooling to the spent fuel pool,
     infrequently used backup systems for spent fuel pool cooling
     and the issue that came out of the AEOD study, which was the
     influence of reactor cavity seals on inventory losses in the
     spent fuel pool.  We focused that review on the seals with
     pneumatic components.
               Giving an overview of the results of the 11 design
     features that were evaluated up in the follow-up actions,
     five design features were reviewed using probabilistic
     analysis and did not meet the screening criteria for further
     evaluation, so they were screened out.
               One design feature category was eliminated from
     evaluation when all the licensees in the category took
     voluntary actions to address the concern.
               DR. KRESS:  Which one was that?
               MR. GRAFTON:  I will go over that.  But that was
     -- the design feature was the anti-siphon devices.  And I
     believe there was four plants that had deep-running pipes in
     their spent fuel pools, and they either committed to cut the
     pipe or to provide certain administrative controls that the
     staff reviewed and found acceptable to address the issue.
               One design feature did meet the screening criteria
     for this design feature, which was the shared systems and
     structures at multi-unit sites.  The staff performed
     additional analysis to determine whether the safety
     enhancement backfit was justified.  
               For the design features where the staff needed
     additional information to determine whether to perform
     further analysis, the staff gathered the necessary
     information during site visits and by reviewing in-house
     material.  And after evaluating the information, determined
     that none of the four requirement further review.  And I
     will go into a little bit more detail on each one of those,
     just so you get an idea of which ones we looked at.
               DR. KRESS:  That is sort of like George's three
     region approach.
               MR. GRAFTON:  For each of the five design features
     listed on this slide, the staff collected plant-specific
     information and performed probabilistic evaluations to
     determine the frequency of each end state.  In each case,
     the frequency of the end state occurrence was low enough
     that the staff concluded that no further evaluation was
     warranted.  The first issue was draining the spent fuel pool
     through the fuel transfer system.  That was evaluated at
               Draining through an interfacing system, again, but
     I repeated myself, but it is Oconee because of the SSF
     system.  An absence of a direct low level alarm and limited
     instrumentation for loss of cooling, the last one, were both
     evaluated at Hatch and Dresden.  And the absence of on-site
     power for spent fuel pool cooling system, in this issue
     there were four sites that had this.  Two plants took
     voluntary actions to supply emergency power to their spent
     fuel pool cooling system, and the other two were evaluated
     and found to have a low frequency of the end state.  
               One of those plants, which was ANO-2, their backup
     cooling method is actually evaporative cooling, so, they
     don't rely on a backup system to cool their spent fuel pool.
               DR. KRESS:  But do they have to make-up water
               MR. GRAFTON:  Yes.  There is a seismic
     qualified -- 
               DR. KRESS:  They have a good make-up, seismic
     qualified make-up system.
               MR. GRAFTON:  Event frequency of one design
     feature exceeded the screening criteria.  This design
     feature was the shared systems and structures.  Thirteen
     plants share this design feature, they are Calvert Cliffs,
     D.C. Cook, Dresden, Hatch, LaSalle, Quad Cities and Point
     Beach.  You notice there is 13 of them, which doesn't make
     much sense, but the design of the Hatch plant isolates the
     Unit 2 safety-related equipment from the spent fuel pool
     area, so only Unit 1 is susceptible to this condition.
               The plants that we used to evaluate this condition
     were Dresden and Hatch.  The staff estimated the frequency
     of sustained boiling events at both of these plants using
     plant-specific information obtained from the site.  The
     results indicated a low likelihood of the events resulting
     in sustained boiling, but one that exceeded the screening
     criteria.  As a result, the staff performed the following
     additional evaluations.
               The staff reviewed an evaluation by the Dresden
     licensee on the effects of sustained boiling event on the
     safety-related equipment in the adjacent spaces.  The staff
     agreed that, considering the low event frequency, the
     multiple reliable cooling systems, plus the low LOCA event
     frequency, makes the likelihood of a sustained boiling event
     that affects safety-related equipment in the reactor
     building a low frequency event.  No backfits were justified. 
     At this plant they have two off-site power supplies and five
     on-site power supplies.
               DR. WALLIS:  What do you mean by low frequency? 
     What is the number?
               MR. GRAFTON:  The number for Dresden, I believe
     was 4.3 times 10 to the minus 6th.  Is that correct, Sam? 
     Do you have that?
               MR. LEE:  You are looking at the total number,
     yes, that is correct.
               MR. GRAFTON:  That was the total number for all
     event sequences.
               MR. LEE:  That's right.
               MR. GRAFTON:  Hatch had a higher event frequency
     for sustained boiling, I believe theirs was, in an operating
     condition, theirs was 4.4 times 10 to the minus 4, okay, for
     operating.  All right.  However, no credit was given for
     contingent actions to restore cooling by operator staff,
     either by supplying temporary power to the spent fuel pool
     cooling system or obtaining a diesel for their auxiliary
     decay heat removal system.  During refueling, the frequency
     for Hatch was calculated -- was actually recalculated for 9
     times 10 to the minus 6th, which was more in line with other
     plants that we looked at.
               Hatch has a unique design.  They have a normal
     spent fuel pool cooling system which is not safety-related
     and does not have emergency power to it, but they have an
     alternate decay heat removal system that, when they do
     refueling, they bring in an auxiliary diesel generator to
     provide emergency power to the system, so it is a very
     reliable system, plus they use RHR in the spent fuel pool
     cooling assist mode, which is also a safety-related system
     that is supplied from an on-site power supply, as another
     method for backup cooling.
               So, if you were to look at Hatch when it is
     operating, the diesel for the ADHR system is not required to
     be on-site because you do not have the high heat load in the
     pool.  Well, without a high heat load in the pool, you don't
     have a rapid heat-up rate and boiling rate, you know, but,
     you know, you do have both plants operating.  So, even
     though they have a high event frequency when the plant was
     operating, there is a low decay heat load in the spent fuel
     pool at that time.  And, conversely, when you off-loaded the
     pool, that is when the frequency went way down because you
     have a much more reliable system.
               One other thing to note about the Hatch system was
     because of the size of the piping, they are not able to use
     the DHR system -- excuse me, the RHR system in spent fuel
     pool cooling mode when the plant is operating, because they
     have to have the top of the plant off and use a circulation
     path that goes from the reactor vessel back to spent fuel
     pool, otherwise, it will cavitate the large RHR pump if they
     just did it recirculating the spent fuel pool.
               So, those individual plant-specific factors are
     what dropped the frequency from the higher rate down to the
     10 to the minus 6 range.
               DR. POWERS:  The auxiliary diesel at Hatch is
     located on-site someplace?
               MR. GRAFTON:  Yeah.  They truck it in.  It
     actually sits on a truck and it is pigtailed out, I believe
     it was outside of the building.  Sam, do you remember that?
               MR. LEE:  That's correct. 
               MR. GRAFTON:  Yeah, they just, they back it up to
     the outside of the spent fuel pool cooling building and the
     rigs sits outside the spent fuel pool cooling building and
     they just pigtail it to the cooling system.
               Regardless, the staff reviewed the licensee's
     evaluation of a sustained boiling event at Hatch and agreed
     that no safety-related equipment would be affected by the
     relatively mild environment created by the sustained boiling
     event.  The staff also concluded that because of the
     differences in plant design, all plants in this group should
     be reviewed for sustained boiling.
               So, we looked at the frequency of it and the
     frequency said that it was a low probability event, but we
     also went in and said, okay, what happens if it does boil? 
     Let's look at where the safety-related equipment is located. 
     Let's look at happens if it were to flood and make an
     evaluation on that.  And we found that the safety-related
     equipment was located far enough away and in an area where
     it would not flood, that we did not feel that there was a
     problem at that plant.
               But because the sites were so unique, when looking
     at Dresden and at Hatch, we said we need to go back and look
     at the other plants that were in this group of 13.  So, the
     staff conducted reviews on Hatch and Dresden.  One of the
     conclusions from the reviews was that on-site power to the
     spent fuel pool cooling system resulted in low frequencies
     of sustained boiling.  So we focused in on the factor that
     brought the frequency down, and that was the factor, that
     they had emergency power to the spent fuel pool cooling
     pumps, it brought the frequency of boiling way down, because
     the systems were very reliable.
               So, when we looked at the other 13 in that group,
     we eliminated or we screened out those that had emergency
     power to the spent fuel pool cooling pumps, and the only
     plant that remained was LaSalle.  And LaSalle had a unique
     configuration that left it vulnerable to a grid-centered
     loss of off-site power.  
               After evaluating the design weaknesses, the
     licensee took voluntary actions that were acceptable to
     staff to address the concern.  They went back in and they
     modified their procedures to ensure that 120 volt power was
     resupplied to two valves in their system that would have
     lost -- they were not supplied with on-site power, and even
     though the pumps were available to operate, these two valves
     would have isolated and stopped cooling to the spent fuel
     pool.  So, the LaSalle issue went away.
               In addition to performing probabilistic
     evaluations, the staff gathered and evaluated further
     information about certain design features to determine
     whether further regulatory actions were necessary.  This is
     the second group, the group of four that we are collecting
     additional information on.  The staff looked at all the
     plants with liner leak-offs to make sure that the make-up
     capabilities exceeded the leak-off rate should a tear
     develop in the liner that maximized the leak rate through
     these leak-off lines.  And we found that all of them did
     have make-up that exceeded that capacity.
               The staff reviewed plants in the group for limited
     decay heat removal to determine whether any additional
     administrative controls were warranted.  The staff found
     that licensees had procedures to take early actions on the
     loss of decay heat removal, to isolate the purification
     system and to line up make-up early.  They also took actions
     to refuel in months where their ultimate heat sink
     temperature was lower and, thus, the cooling systems that
     reject heat to the ultimate heat sink were lower.
               We found that they did not have a problem, even
     though when we looked at their design numbers, and when you
     take into consideration the design of these plants, you look
     at the maximum heat load and the minimum capability to cool
     it, so the highest ultimate heat sink temperature, what
     their actual practices were, they would tend to refuel in
     off months and they were able to keep their temperatures
     well below even though their low temperature alarm of 125
               For the refueling cavity seal issue, AEOD
     identified a loss of the seal during refueling could
     dramatically lower the spent fuel pool level.  The staff
     previously reviewed this issue in response to an event at
     Haddam Neck in 1994.  The staff found that no plant was
     vulnerable to this type of failure, to the type of failure
     experienced at Haddam Neck.  
               Design changes included those that employ a solid
     wedge type primary seal to reduce the probability of
     significant leakage through the seal.  Other seals employ
     similar design features or ones that act to reduce flow from
     the reactor cavity seal should a leak occur. 
               There was -- I believe there was four plants with
     this design that had pneumatic components to them.  We
     looked at all of them and we felt confident that the work
     that was done in response to the bulletin in 1994 would
     limit the flow out of a cavity seal such that the spent fuel
     pool could be isolated if one of these minor leaks were to
               DR. WALLIS:  What is the life of these seals?
               MR. GRAFTON:  That I don't know.
               DR. SIEBER:  I think that the probability of a
     malfunction during installation or removal, or the failure
     of the air supply pressure to the seal itself is more common
     than the seal just aging and falling apart.
               DR. WALLIS:  Because it does eventually age,
     doesn't it?
               MR. GRAFTON:  It does age, but they are all tested
     prior to having them, you know, filled and aligned.  They
     put them in place and then with the spent fuel pool
     isolated, they fill the area around the seal and check for
     leakage.  So, it is tested in place.  If it were degrading,
     it would -- 
               DR. WALLIS:  Then replacing a seal is not -- to
     what activity?
               MR. GRAFTON:  I would I think it would be
     extremely large activity.
               DR. WALLIS:  I think it would be, wouldn't it?
               MR. GRAFTON:  Yes.
               DR. KRESS:  I recall Sandia did some aging studies
     on those seals, and there are numbers for how long they
     last.  I don't recall what the results were, but there were
     values available for that.
               MR. GRAFTON:  I am not familiar with their
     inspection activities on the seals, so I can't comment on
               DR. SIEBER:  What is your modification to the
     gates that close the gap between the wall of the pool and
     the edge of the gate, so as to minimize the flow through a
     failed seal?
               MR. BARTON:  That sounds familiar.
               MR. GRAFTON:  Are you talking about spent fuel
     pool gates?
               DR. SIEBER:  Gates, where the seals are.
               MR. GRAFTON:  There was an event, and I believe it
     was at Hatch, where they had a gate that had a double seal
     but it was supplied from the same air supply.
               DR. SIEBER:  Right. 
               MR. GRAFTON:  And the air supply failed and caused
     a leak through that gate.  And they came back and they split
     the air supplies such that, you know, half the seals were
     provided from one unit's air supply, the other one from the
     other air supply.
               DR. SIEBER:  I seem to remember some kind of a
     physical barrier that they installed to help close that gap.
               MR. HUBBARD:  This is George Hubbard.  Jose Ibarra
     just told me, I guess from the AEOD study they looked at,
     and the cavity seals are periodically replaced.
               MR. GRAFTON:  For the infrequently used backup
     system, the staff verified that the backup systems are
     aligned and tested before they are put in use, and there are
     administrative controls to ensure that these systems are
     operated properly.
               One other note was that we found that the
     licensees employed outage safety assessments in a manner
     consistent with NUMARC 91-06, Guidelines for Industry
     Actions, which gives outage safety guidelines for ensuring
     that there is adequate core in spent fuel pool cooling at
     each site.  So, for the sites that we looked at infrequently
     used backup systems and the limited decay heat removal
     capability, this -- each one of those sites had guidance
     documents that ensured that the systems were available,
     i.e., they had all their maintenance performed on them
     before the outage would start, and they were tested in place
     before they were needed to be used during the refuelings.
               To sum up what's been presented, the technical
     issues that were identified by the Part 20 report, and the
     issues identified during the Generic Spent Fuel Pool Task
     Action Plan, have been evaluated by the Staff, and found
     that the plants are in compliance with the current
               The Staff's identified design features as a result
     of the review that we felt warranted further review and
     evaluation to determine whether the safety enhancement
     backfits were warranted.
               Some design features received regulatory analysis;
     others, the Staff gathered information on about the design
     feature.  As a result, the Staff could not justify safety
     enhancement backfits at any plants.
               The Staff completed their review of all technical
     issues, and we plan to close GSI-173 on this basis.  
               DR. KRESS:  Let me ask you a question about the
     backfit procedures, rules, backfit rule:  You have a safety
     goal screen, and then you look to see if there is
     substantial increase in protection of the health and safety,
     and substantial decrease in the risk.
               And then you look at cost/benefit.  Where is the
     substantial stuff?  Is that in there before the safety goal
     screen or after it, or is it a part of the safety goal
     screen somehow?  
               I didn't see any here where you looked at delta
     changes and asked if this was a substantial or not, and I'm
     not sure where it fits into the regulatory analysis.  
               MR. LEE:  This is Sam Lee.  We didn't look at a
     delta, per se.  When these plants were identified as having
     unique features, we wanted to take a look at what the -- I
     don't want to say the word, risk, because the end state that
     we evaluated were far, far -- were pretty conservative.
               MR. COLLINS:  This is Tim Collins.  Dr. Kress, in
     regard to your general question.  Substantial would come
     after the screen.  First, you get passed the screen, and you
     don't even look at substantial.
               Then you look at substantial, just in case.  You
     may get a very small benefit, which is still cost-
     beneficial, because of the very small cost associated. 
     Okay, so first you've got to get by the screen, and then it
     has to be substantial enough to make it worthwhile at all.
               Those are really the steps: Screen, substantial,
     cost-benefit, right.  
               MR. GRATTON:  Anyway, that's the end of my
               DR. KRESS:  I have no more questions.
               DR. WALLIS:  Did someone on this Committee look at
     this report?  
               DR. KRESS:  I did.  
               DR. WALLIS:  So the report has been -- I want to
     make sure it isn't an oral evaluation because -- 
               DR. KRESS:   We had intended to have some
     committee meeting on this, but we decided we could look at
     the reports and handle it all in one full Committee meeting.
               Are there any other questions?
               CHAIRMAN POWERS:  I'm still a little uncertain on
     where we stand with these spent fuel pools as a risk
     contributor.  It looks to me like this analysis looks very
     much at the boil off scenarios.  
               And the question comes about, what about the drain
     off scenarios initiated by the seismic event?  It looks to
     me like it looked at primarily the facilities susceptible to
     design basis earthquake damage, and they're not -- they're
     design to meet that earthquake.
               DR. KRESS:  Yes.
               CHAIRMAN POWERS:  And so we come back to Dr.
     Wallis's question.  Surely there is some earthquake that
     will fail those, and with some repeat frequency.
               And so what is that risk?  What risk do they pose
     when you consider those earthquakes?  I guess I don't have a
     real good feel for where we stand there.  
               MR. HUBBARD:  Let me refer you back to the GI-82,
     which took a look at whether the zirconium fire at an
     operating plant -- and that was done back in, oh, mid-80s. 
               And based on that study, it determined that the
     seismic risk was the significant contributor to it, the
     spent fuel pool zirconium fire.
               But from that study, we were not able to justify
     backfitting that on industry, as the licensing basis or a
     design basis requirement.
               And it may be that you want to go back and take a
     look at the GI-82, which I think probably more addresses
     your question.  
               DR. KRESS:  What was the basis for the lack of
     justification?  Was it also a safety goal screen, or was it
     a cost/benefit?
               MR. HUBBARD:  I believe the answer is, yes, it do
     a cost/benefit.  It was a safety goal screen, yes.  So I
     think that for that issue, the whole regulatory process was
     followed for, you know, justifying the backfit.
               And we were unable to justify the backfitting.
               DR. KRESS:  Does the -- how -- this is a
     regulatory process question, I guess.  If you read the
     backfit rule, it doesn't -- it's silent about safety goal
               But if you look at your Regulatory Analysis Guides
     for rulemaking and backfitting, that's where you see the
     safety goal screen brought up.
               And it tells how to do it, and gives acceptance
     criteria, or gives a matrix for what you do, depending on
     various values.
               The Regulatory Guide, does that bind you to
     actually go by the results that one gets from following the
     Regulatory Guide, or is that just -- or do you have a lot of
     flexibility in looking at that and saying, oh, maybe that's
     not quite appropriate for the given case or something?  How
     binding is that on your ability to do a backfit or
               MR. COLLINS:  It's not binding.  You can make
     recommendations which take into account, other
     considerations which you can't quantify.  So the Guide is
     really a guide, yes.
               DR. BONACA:  I had just a question.  As we look at
     these power plants, most of them were designed with spent
     fuel pools, and there was an understanding that by sometime
     in the early 80s, fuel would be taken out. 
               Most of them were not ever filled their pools.  In
     fact, many of them right now around with full spent fuel
     pools, and they're putting additional fuel in dry
     containment storage and so on and so forth.
               I think there has been some kind of true shift
     here in the scenarios we're looking at insofar as spent fuel
     at sites.  Have you thought at all as you were reviewing
     this issue of the spent fuel pool, about the fact that there
     has been truly a shift.  
               These facilities now have, if you go and travel
     around, you see that they have spent fuel pool full, some of
     them are expanding, like the Sharon Harris facility where
     they will have literally each pool 4,000 assemblies of
     different types, loaded and supported by the same systems.
               And many of these sites have also now dry storage
     facilities there.  I mean, you know, it's a different
     scenario from what we envisioned in the early 80s.  
               Have you given any thought about how that would
     affect to some degree, this issue of spent fuel storage?
               MR. HUBBARD:  I think the answer is, yes, we did
     put some consideration to it.  And, in particular, when a
     utility comes in and looks at the -- you know, they ask for
     a re-rack or increase in their capacity, you know, we look
     at it from the thermal hydraulic standpoint, the
     criticality, the structural standpoint. 
               The Division of Engineering gets involved in
     looking at these issues.  The people, Chris and the others,
     Steve Jones, who was involved in this very deeply, was very
     well aware of the fact that now we're dealing with more fuel
     in the spent fuel pools.  We're packing them in tighter, and
     that was part of the consideration.
               As you go through this, it's concern with having
     the more fuel there is, you know, the temperature control. 
     You know, what is the -- 
               DR. BONACA:  Well, I think there is a rising
     public expectation for this final repository somewhere.  I
     will expect that we will see a rising public interest on
     these repositories that are not anymore temporary.  In fact,
     in some cases, they may become permanent.  
               MR. HUBBARD:  Yes.
               DR. BONACA:  There is a real shift there, and I
     notice also a shift in public interest.  
               MR. HUBBARD:  And I think definitely there is the
     shift.  As you mentioned Harris, you know, license amendment
     that's before a hearing panel, Millstone III also is in for
     a re-rack.  
               There is public interest there, so, one of the
     issues that got us even more focused on this was the
     Millstone I and the Time Magazine article.  
               And so we were quite aware of the increased
     storage, and, you know, the public interest.  And it's --
     you know, yes, people are concerned, and we are aware of
               CHAIRMAN POWERS:  It looks to me like the
     resolution of this issue is focused very much on full
     probabilities of occurrence.
               And I don't have a good feeling for the actual
     risk, because as a strong believer in the structural
     component of defense-in-depth, I said, well, you can prevent
     accidents only so far.
               I have qualms about or arguments about those to
     ten to the minus fifth or ten to the minus sixths kinds of
     levels.  What about consequences of these accidents?
               I don't have a good feel for what that product of
     probability times consequence is.
               DR. WALLIS:  I think there is also the question of
     how risk averse you are; that these things get less likely
     but have bigger consequences.  It's not necessarily a linear
     process that you go through in evaluating your criteria for
               DR. KRESS:  Well, I certainly share Dana's
               CHAIRMAN POWERS:  You don't believe in prevention
     lower than ten to the minus fifth or ten to the minus sixth,
     and, you know, there are not too many options here, unless
     you're going to build a containment over it.
               DR. KRESS:  You almost have to rely entirely on
     prevention, and some mitigation, based on operation action.  
               But the question is, have we provided enough
     prevention based on the real risk?  And that involves
     knowing what the consequences actually are.
               DR. SHACK:  Just coming back to Dana's question
     again, when we went through for the decommissioning plants,
     I thought the seismic was really the thing that left you out
               And what was the fraction of plants when you -- I
     mean, there they looked at the severe earthquakes, and there
     was a  -- what was the fraction of plants that didn't have
     the high confidence?
               DR. KRESS:  I don't recall, but the problem is
     that with decommissioning plants, there are a limited number
     of those at any given time, and a limited amount of time
     they're at risk.  
               You know, the risk goes away after a certain
     amount of time.  
               DR. SHACK:  After a couple of months.
               DR. KRESS:  Here we're talking about operating
     plants where the risk is there all the time.  And it's all
     of them.  So it's quite a different situation.  
               DR. SHACK:  You don't know how often the pool is
     going to get busted up.
               DR. KRESS:  Well, that should be part of a risk
     analysis, and that's what Dana, I think, is partly asking. 
     Do we have a good feel for what the full number of -- the
     full probability is and the full consequences, which we need
     to know for the full risk equation?
               And whatever that value is, which maybe we have to
     go to this GI-82 to find out something about it.
               Then the question is, is that an acceptable number
     to us, even though there are no risk acceptance criteria out
     there that are binding by law, other than the safety goals.
               And so, I think that's the question that bothers
     Dan and bothers me also, is, I don't have a good feel for
     what the risk actually is, because I haven't seen a good
     convolution of the frequency times the consequences.  And
     that's the thing that bothers us.  
               CHAIRMAN POWERS:  The question comes up that
     you've got some coupling between these systems and the
     systems of an operating plant.
               And so when I come in to use Reg Guide 1.174 and I
     want to locate myself on a horizontal axis, is this
     probability big enough that I need to take it into account? 
     If I locate myself on that horizontal axis, and is the
     change that I'm proposing to the plant causing a delta in
     this risk that I need to consider, along with the delta on
     the normal operation risk?
               I don't have a good feel for that.  
               DR. KRESS:  I don't either, and it's a good
     question, because I don't think 1.174 deals much with spent
     fuel pools.  
               CHAIRMAN POWERS:  I think it's a stepchild of all
     of them.
               DR. KRESS:  A stepchild of all them.
               CHAIRMAN POWERS:  One of the things that people
     struggle with, I think, when we ask these questions, typical
     PRA really doesn't make the rest.  
               DR. KRESS:  For example, how would a PRA determine
     the effects of steam on safety equipment and a change in
     reliability of that, given the number of hours of exposure
     or something?  You couldn't deal with it very well.
               CHAIRMAN POWERS:  I'm not sure we have  good
     database, deterministic number on that.
               DR. KRESS:  I don't think we have, either.  So,
     it's a question that is another one of those model
     uncertainties that you have to deal with with defense-in-
     depth, I think.  How much defense-in-depth do you put on it? 
     I don't know.  
               Well, you can see what's bothering us.  
               MR. HUBBARD:  I tried, in looking at it, is that,
     you know, we did the GI-82, and determined that we couldn't
     backfit the zirconium fire.  We had these issues that came
     up with regard to Susquehanna.  
               We took a look and addressed the Susquehanna
     issue.  We then took the bigger generic look, taking to see
     did the plants -- do they meet our regulations?  Is there a
     big concern there?
               We identified that the plants were meeting our
     requirements or guidance.  Except in some cases, we went and
     made plant-specific backfits, and so, you know, we came to
     this conclusion, and as you probably have recognized, we
     probably haven't been looking at operating plants.  
               We probably should have asked you, when you asked
     us whether we wanted a letter from you back in '96, we
     should have said, yes.
               We didn't, so, the thing that I would like to also
     mention is the fact that the operating plant still has its
     full EP, you know.  That's there.
               You've got the full complement of safety and non-
     safety systems that, you know, we've had all along.  And I
     think the biggest part of risk at the operating plant is the
     reactor itself.
               And, yes, we didn't go through and carry this
     through to give you other than the GI-82.  We didn't go
     through in this effort that we've been doing in the 90s to
     carry it through to the risk which includes consequences. 
     And that's your concern.
               CHAIRMAN POWERS:  Maybe the situation here is that
     -- maybe you've got a specific question that's addressed by
     this GSI.  Maybe this is resolved, this specific question,
     but we've got this larger question that Art Bonaca
     mentioned.  It's a permanent feature that's not going to
     change until the Department of Energy gets its act together.
               Spent fuel storage -- 
               VOICE:  I can't hear you.  
               CHAIRMAN POWERS:  Storage -- and maybe we need to
     look at it in a more holistic fashion, independent of this
     specific question, because this is a fairly specific
               DR. KRESS:  What is the specific question being
     asked of this GSI?  I think it is, are there particular
     vulnerabilities to loss of spent fuel pool cooling and loss
     of inventory.  
               And I think you have to think the risk issue is
     tied into the answer to that question, because that's what
     you mean by vulnerabilities.
               I don't think we can divorce this particular issue
     from the question of risk.
               DR. BONACA:  The reason I raised that issue before
     is that it ties into the issue of consequences.  I mean, the
     size of, the amount of spent fuel in the pools, as well as
     in the dry storage, et cetera, has created really a
     different kind of scenario from what we saw just a limited
     number of batches discharged and they're removed from the
               So, to some degree, it ties into the issue of
     understanding the potential.
               DR. KRESS:  Every couple of years, you get a fresh
     load of fuel.
               DR. BONACA:  That's right, and you add up, and you
     have thousands of assemblies now sitting there.  So, it ties
     into the consequences.
               DR. KRESS:  I'm reluctant to divorce this issue
     from the risk.  
               Any further comments?
               [No response.]
               CHAIRMAN POWERS:  Thank you very much.  I think
     that was a fine briefing that you gave us.  I very much
     enjoyed it.
               We'll recess now until 17 after the hour.
               CHAIRMAN POWERS:  Let's come back into session.
               Our next topic is one I am really looking forward
     to. We have assumed that in the move for greater use of risk
     that indeed we would be able to have a more quantitative and
     better understanding of regulatory effectiveness and as a
     first step in that area we are moving toward -- we are going
     to hear a briefing on the regulatory effectiveness of the
     station blackout rule.
               Mario, I think this is a topic you are going to
     lead us through?
               DR. BONACA:  Yes, Mr. Chairman.
               We have a report in front of us that shows that
     the station blackout rule has brought significant risk
     reduction on the one hand, and it will be interesting to the
     committee to see the specifics of it.
               It also shows that some of the benefits obtained
     by the implementation of the rule are somewhat being eroded
     by some conflicting guidance and regulation and there are
     opportunities there for reducing this erosion by some
     clarification, so I think it will be an interesting thing
     for the committee to look at how the special blackout rule
     was implemented and the benefits brought about and the
     opportunities there.  
               With that I will let the presenter go ahead.
               MR. ROSENTHAL:  I am Jack Rosenthal. I am the
     Branch Chief of the Regulatory Effectiveness Assessment and
     Human Factors Branch in the Office of Research.
               Our office director, Ashok Thadani, asked me to
     make some introductory comments.
               We try to relate our work to the Agency's goals
     and we have this initiative to look at the effectiveness of
     major rules, which is clearly related to the maintain safety
     goal or factor, and you will hear about that.
               Equally or perhaps more important, throughout the
     Agency, another one of our goals is to make things more
     efficient and effective and we used this as almost a
     buzzword and it means different things to different people
     throughout the agency, and sometimes, often we are talking
     about it in terms of our internal processes, so here is an
     example now in our branch where we are trying to look
     external to the Agency and to say, okay, has this Agency
     been effective in achieving its desired outcomes external to
     the Agency.  I think it is an important piece of work.
               We are budgeted to do about two rules a year.  The
     first one out of the chute is the blackout rule.  Shortly
     thereafter we will look at, we will publish a draft report
     on ATWS, then we are going to look at Appendix J, Option B,
     for which we put in a lot of work and want to see what it
     would get for us.  After that, we are going to take a look
     at the resolution of A-45, decay heat removal, which did not
     result in a rule but there was considerable action, and then
     we will march out in time from there and there will be
     progressively more external impact on how we pick our rules.
               The particular report now is a draft report and we
     decided that it would be better to come to the ACRS as a
     draft where you have an opportunity to influence the product
     rather than to come with a final and say it's done, so that
     is the mode we would like to be in.
               But it is a draft report and we have already
     gotten comments internal to the Staff that have been
     incorporated in the report and we have provided it to Union
     of Concerned Scientists, Public Citizen, EPRI, NEI, INPO, et
     cetera, for public comments.  I think now is an ideal time
     to publicly discuss what is in the report.
               With that, I am going to turn it over to Bill.
               MR. RAUGHLEY:  What we are talking about is the
     draft report, Regulatory Effectiveness of the Station
     Blackout Rule.  As Jack briefly  mentioned, this report
     reflects comments made by NRR and the Regions and that we
     have asked the industry for their comments, specifically the
     reasonableness of the approach, the appropriateness of the
     conclusions, and what other rules, Reg Guides, inspections
     procedures that we should address as part of this regulatory
     effectiveness process.
               I am addressing this in the context of you were
     asked to be informed about the paper -- so I'll pick certain
     highlights to speak to.
               As some background, the report will provide a
     basis to respond to the Commission.  We expect to write a
     SECY after revising the report to address the industry
     comments.  The Commission first asked the question after
     hearing about the NUREG-1560, which provides the
     perspectives on reactor safety, and that was back in 1997.
               At that time that NUREG showed a station blackout
     and ATWS to be dominant contributors to core melt and the
     Commission asked what about the effectiveness of the SBO and
     ATWS rules in view of that, and then this became an action
     item in the PRA implementation plan.
               Station blackout is defined in 10 CFR 50.2.  It is
     a complete loss of offsite and onsite AC emergency power and
     a turbine trip.  The risks were first known in WASH-1400,
     1975 report that highlighted the station blackout could be
     dominant, and if you look at the 1560 which summarizes the
     IPE PRAs for all the plants in the industry you would
     conclude it is a dominant or the dominant contributor to
     core melt.
               As far as some historical highlights before the
     station blackout rule was passed there were requirements to
     address offsite and onsite power.  Specifically we are in
     the 1974 to 1977 timeframe.
               We had Reg Guide 1.93, which addressed or required
     LCOs, limiting conditions of operation, when you have less
     than the required number of either offsite or onsite power
     supplies and if those problems persist for a certain amount
     of time they are required to go to hot shutdown and
               There is Reg Guide 1.108, which has since been
     cancelled but that required tests to demonstrate the
     reliability, and those of you familiar with the topic may be
     familiar that plants were required to do 69 tests per site,
     23 per plant and to demonstrate diesel reliability with no
               That Reg Guide also speaks to EIS CB-2.  It is
     Branch Technical Position from the Electrical and Control
     Branch, which is part of the Standard Review Plan and that
     establishes that these are reliability goals, 99 percent at
     a 50 percent confidence level, so it is a point estimate.
               Reg Guide 1.9 has been revised several times but
     that basically addresses start and load testing as EQ
     testing of the diesel when it was originally purchased, and
     you may recall that was the famous 300 start/stop test with
     no failures.
               Some of the evolution to the SBO rule, the
     Commission, A-44, is an unresolved safety issue.  The
     Commission thought that in view of events in the late '70s
     dealing with loops and diesel unavailability that this
     should be a generic issue.  Just some of the scores at the
     time -- there were 11 of 78 plants surveyed had less than 95
     percent diesel reliability, two of 78 had less than 90
     percent reliability, only seven of 57 sites monitored diesel
     reliability and only three of 56 sites surveyed kept records
     of diesel reliability.
               In response to A-44, the Staff issued NUREG-1032,
     and this integrates the results of several engineering
     analyses that were completed.
               DR. WALLIS:  If they didn't keep records of
     reliability, how did you know that they were 90 percent
               MR. RAUGHLEY:  The NRC had sent out an information
     notice and asked people for bean counts.
               DR. WALLIS:  They hadn't been keeping records so
     maybe this was an assessment other than based on tests?
               MR. RAUGHLEY:  There was a Generic Letter, an IN
     sent out, and I guess they provided them with the
               NUREG-1032 pulled together several engineering
     studies that were done by contractors for the NRC to address
     different aspects of station blackout.  That report provided
     four findings or results that provided the basis for the
     station blackout rule and the accompanying Reg Guide 1.15. 
     That is that the station blackout was highly dependent on
     the redundancy and reliability of the EDGs and it was also
     highly redundant on the frequency and duration of the loops.
               The NRC also performed a regulatory analysis which
     provides the cost benefit analysis of implementing the
     station blackout rule and that was documented in NUREG-1109.
               The station blackout rule itself, there's three
     basic parts -- (a) requires that the licensees be able to
     withstand the station blackout for a certain amount of time
     and recover from that event, and that the duration of
     station blackout is based on the four factors I mentioned
     from NUREG 1032, and it requires licensees to do a coping
     analysis to demonstrate the degree to which the support
     systems will support a station blackout, and lastly it asks
     licensees to specifically supply the coping duration based
     on the plant design factors they picked, procedures offsite
     and procedures to cope with an SBO specifically in terms of
     recovery from loss of either or both of onsite or offsite
     power and to make any modifications necessary to achieve
     desired coping times.
               Other documents that are related to the rule are
     highly important in our assessment.
               Reg Guide 1.155 was the Reg Guide that accompanied
     the station blackout rule and that establishes specific
     diesel reliability requirements, that they be .95 or .975
     reliable.  It requires or provides guidance for reliability
     programs.  It provides guidance for procedures to restore
     offsite and onsite power and it provides the tables --
     there's eight or ten tables -- that they go through to
     determine the coping capability based on severe weather
     condition category, offsite power configuration, onsite
     power configuration, et cetera.
               DR. WALLIS:  If 95 percent is the number and the
     reliability of a truck diesel is 99.999 and they always
     start -- why is this not the same?
               MR. RAUGHLEY:  I don't know.
               CHAIRMAN POWERS:  Big diesels?
               MR. BARTON:  Big diesels that were designed to run
     all the time but they sit there.
               DR. WALLIS:  They sit there.  That's the problem.
               DR. KRESS:  And they have to have a signal to
     start them up.
               MR. ROSENTHAL:  Let me also point out that what
     you are talking about is the emergency start of a standby
     electrical power station, and that the focus has been on the
     diesel engine but it includes the diesel engine, the
     generator, the voltage regulator, the output breakers, the
     support systems, air support systems dependency, service
     water dependencies, et cetera, et cetera, so you are really
     starting, emergency starting a small power station and when
     we go today and when we look at the reliability of the
     equipment, which we will hear about later, it is meeting the
     goals but the problems involve not so much the engine as the
     output breaker or some service water dependency or the
     voltage exciter, et cetera, et cetera tends to be a lot of
     the peripheral equipment.
               DR. KRESS:  You are going to tell us how you
     verify that the reliability has been met?
               MR. RAUGHLEY:  Yes.
               DR. KRESS:  Okay.
               MR. RAUGHLEY:  Two slides up.
               The two documents in parentheses, the first one,
     NUSTACK-108 is an EPRI document that the Reg Guide 1.15
     relies on for the definition of valid starts and stops and
     the Reg Guide also offers a NUMARC document for an alternate
     means of compliance and that closely parallels the Reg
               The station blackout rule resolution specifically
     referred the details of the reliability program to the
     resolution of Generic Issue B-56, which is diesel
     reliability and that resolution tied the reliability program
     to the maintenance rule, so we get into a lot of maintenance
     rule documents -- Reg Guide 1.160, the corresponding NUMARC
     document 9301, which references another NUMARC document,
     which refers to Rev. 1 of NUMARC-87-00.  We have the
     inspection procedure and there is a maintenance rule
     handbook so that there's a number of documents.
               As far as the assessment, the definition we picked
     for regulatory effectiveness was that a regulation is
     effective if the expectations are being met.
               DR. WALLIS:  I am not sure that many regulations
     are too clear about the expectations --
               MR. RAUGHLEY:  I'm sorry?
               DR. WALLIS:  Just I am not sure that expectations
     are specified in a way that enables measurement of them but
     I see regulations, so I would like to see a much clearer
     statement of what an expectation is from them in the
     statement of considerations or something, and it often isn't
     there, so I wonder how you determine what the expectations
     really are.
               MR. RAUGHLEY:  It's on the next --
               DR. WALLIS:  Maybe the next station blackout rule
     has a good job done on expectations.
               MR. RAUGHLEY:  There could be very objective
     expectations in terms of diesel reliability, costs, risk
     reductions, coping time.  This is one of the more --
               DR. WALLIS:  Explicit --
               MR. RAUGHLEY:  -- performance-based, risk informed
     rules that we have, I think.  It is quite quantitative.
               I'm doing the ATWS rule also, but that's not the
     case.  But the deregulation within the regulation would
     include the rule, the accompanying Reg Guide, and the
     accompanying inspection documents.  
               But the scope of the assessment was to determine
     if the rule is effective and if there are any areas that
     need attention.
               I didn't try to second-guess.  I worked only from
     documentation.  I worked only from publicly available
     information.  I didn't try to second-guess or read anything
     into it.
               I didn't rely on what people said they did, just
     tried to keep it objective.
               DR. WALLIS:  Now that you've set the standard, we
     can use these when we look at others.
               MR. RAUGHLEY:  That was the point, we would
     address something that was a little cleaner than others and
     maybe have a template to address other things that maybe
     aren't as effective.  
               I did not address plant-specific problems.  One of
     the comments from the internal review I did have some plant-
     specific problems in there, and the consensus was it drew
     too much away from the station blackout rule itself, and
     drew too much focus to plant-specific problems.
               And consistent with the original station blackout
     rule, which didn't address seal failure, we did not either,
     however, that was resolved by RES on 11/99.
               DR. SIEBER:  Isn't the seal failure for a number
     of plants, though, the dominant pathway to core damage?  So
     if you don't address that -- 
               MR. RAUGHLEY:  That was addressed as a separate
     generic issue. 
               DR. SIEBER:  But you did put a number in there
     that says the risk, the overall risk of SBO includes
     potential for seal failure in certain plants, and that
     dominates the risk?
               MR. RAUGHLEY:  That number is in the risk numbers
     in the appendix of the report.  Again, I did what the
     station blackout did, so it deferred the resolution and the
     discussion.  That's all another subject.
               DR. SIEBER:  Okay.  
               MR. RAUGHLEY:  But as a matter of interest, I did
     point out in the report that there's a paragraph in there
     that discusses an 11/99 resolution if GSI-23.  The method
     was, we compared the expectations to the outcomes in areas
     where we could find objective measure being risk, value
     impact, coping time, and reliability.  
               And we used operating experience trends to look at
     the loop frequency and duration.  They were readily
     available in NUREG 54.96.
               The data, I used publicly available data.  We
     obtained the expectations from NRC documents.  
               There's an FRN which is very detailed, that issued
     the station blackout rule as the statement of considerations
     of all the relevant documents and summarizes the relevant
               For the outcomes, I used the NRC databases of the
     IPE.  I developed from the IPE, LERs, the station blackout
     rule safety evaluations completed by NRR and several NRC EDG
     reliability studies that were completed and a few in
               DR. WALLIS:  Are you going to go through the
               MR. RAUGHLEY:  Yes.  The areas that we addressed,
     as I mentioned, were risk, value impact, coping time, and
     EDG reliability.  In the area of risk, the expectation was
     that the mean industry SPO CDF would be reduced by 2.6 E to
     the minus five.  
               And we actually achieved a reduction of 3.2 E to
     the five.  And what the rule did was, it had five or six
     licensee-specific IPE PRAs.  I believe the NUREG 1150 plants
     had models of its own, and from that it was able to
     determine that the average mean SBO CDF was 4.6 or 4.2 E to
     the minus five, and it set a goal to reduce that to 1.6 E to
     the minus five.     
               In fact, the industry average is 1.0 E to the
     minus five.  
               As it turns out, what I did is, I rank-ordered the
     plants from the highest to lowest loop initiating
     frequencies, so those -- there were 21 plants that had a
     loop initiating or loop frequency of .1 or greater. 
               And 15 of the 21 plants had an alternate AC power
     supply.  Nineteen of these 21 plants had reduced their
     station blackout CDF to less than ten to the minus six.  
               Eight plants that had the most severe weather
     category, ESW-5, and the ten plants that had the eight-hour
     coping time, also had alternate access power supplies.
               What we did find is that the Reg Guide 1.93, which
     I mentioned before, requires plant shutdown with less that
     the full complement of power supplies, and in the context of
     station blackout, that would add risk, so we address that in
     the conclusions.
               In the area of value impact, that was completed in
     NUREG 1150, and it's dependent on the risk and estimates of
     the mods that were expected from the station blackout rule.
               And what the NRC did is, they issued that as a
     draft, initially, and significant revisions were made as a
     result of industry comments that our costs were too low, so
     we ended up using their numbers.
               So the basis was to establish them on our risk
     number and their cost estimates.  And it was done on averted
     rem and it gave a range of values, and the result is that we
     are just within the range of values.
               But there are two reasons for that.  One is the
     original expected that 39 plants would make modifications. 
     And at least 72 made modifications.
               These ranged from adding diesels, to making cross
     ties, to changing, upgrading battery sizes.  There were
     several hardware modifications made.  This just wasn't a
     paper exercise.
               DR. WALLIS:  Why didn't the averted rem go up?
               MR. RAUGHLEY:  The averted rem stay the same, but
     the costs -- 
               DR. WALLIS:  Why didn't they go up?
               MR. RAUGHLEY:  The original cost was based on 39
     plants making modifications, and actually 72 did.
               DR. WALLIS:  I can see why the cost goes up, but
     surely the averted rem would also go up; wouldn't it?  I
     don't know why it stayed the same.
               MR. RAUGHLEY:  Well, it went down, the risk went
               DR. WALLIS:  The person-rem seemed to stay the
     same.  I would expect it to have changed, to have gone up,
     actually.  You've done a better job so you've averted more
     rem; haven't you?  
               MR. RAUGHLEY:  But you spent significantly more --
     four times more money.
               DR. WALLIS:  I understand that.  The money, I
     understand, but the rem, shouldn't the rem change, too? 
     You've changed the CDF.
               MR. RAUGHLEY:  The rem would go down in
               DR. WALLIS:  But it stays the same, the same
     number of averted rem.
               MR. RAUGHLEY:  The arithmetic worked out -- 
               DR. WALLIS:  It puzzles me.  I think that would
               MR. RAUGHLEY:  The cost that was expected that
     they would spend $60 million, and they actually spent $200.  
               DR. WALLIS:  So this averted person-rem is
     calculated, though, but -- 
               MR. ROSENTHAL:  Let me try again.  If there were
     plans that chose to add additional equipment, such as chose
     to add a diesel, and they may have made that choice for a
     combination of risk and also operational convenience, and
     there are circumstances where they are incurring the costs
     or racking the cost of that additional diesel against the
     blackout rule.  
               But in the risk analysis, there isn't a
     corresponding -- 
               MR. RAUGHLEY:  Reduction.
               MR. ROSENTHAL:  Reduction of risk, but rather that
     diesel was added because they thought it was proper to do,
     or it gave them operational flexibility, et cetera.
               And that's why -- 
               DR. WALLIS:  You've reduced CDF by this three to
     minus five, which sounds great.  Why isn't there some change
     in your expected averted rem because you've done better on
               DR. KRESS:  Well, it's not much better.  It's
     about the same, and so you get about the same averted rem as
     you were expecting, I think.  
               DR. WALLIS:  I was just puzzled that someone had
     carried the same calculation over without changing it.  
               DR. SHACK:  It's the same rounded off.  
               DR. KRESS:  I think it's roundoff of significant
     figures or something, 2.6 and 3.2, in my mind, are the same
     thing, so you get about the same.
               DR. WALLIS:  Well, the 145 and 145 are exactly the
               DR. KRESS:  Yes, that is peculiar to some extent,
               MR. RAUGHLEY:  I will get back to you with the
     specific arithmetic. 
               DR. WALLIS:  It will look better if you do.
               MR. RAUGHLEY:  Pardon me?  
               DR. WALLIS:  If you check it, it might look
               MR. RAUGHLEY:  Well, what I did there was, I made
     a list of the mods which are an appendix to the report from
     the licensee submittals.  I used the industry estimated
               Licensees also added power supplies.  There were
     19 diesel generators added.  
               Davis Besse was the only licensee that supplied a
     cost estimate for the diesel additions, so we used that for
     the others.  They said they spent $9.07 million.
               They had a non-safety diesel, and they received $5
     million.  They estimated $5 million in cost benefit from
     reduced outage time and increased additional -- not having
     to replace power.  
               In the area of coping time, the Reg Guide provided
     for licensees to select two-, four-, eight-, or 16-hour
     coping times.  And most of the licensees ended up in the
     four- and eight-hour range.  That's documented in an
     appendix in the back of the report.  
               In the area of diesel reliability, the Reg Guide
     required that the licensees establish a goal of 95, based on
     individual diesel reliability. 
               We have a report, INEL report that was done in
     1995 for diesel operating experience between '87 up through
     '93.  I used a draft report that's out for comments, which
     updates the operating experience from '87 through '98, so I
     relied on that because it has more of the post-station
     blackout rule operating experience.
               But that report uses the unit average train
     performance.  And so you sort of are comparing an apple and
     an orange here, but you have to recognize that if the
     individual reliabilities -- well, if the safety performance
     is better than 95, then the individual reliabilities would
     have to be that.
               It would be conservative.  The INEL report is
     conservative in that it may not show all the diesels that
     have less than 95 percent reliability, but nonetheless,
     that's what we had to use.
               What was good about the INEL report was that it
     developed a standard model for diesel reliability.  So all
     the licensees have different ways they've modeled the
     diesel, so what it did is, it created its own model, and
     then it dissected each PRA to take the inputs and run it
     through their model.  So we have a consistent comparison
     across the industry, and I thought that was really good to
     get away from all the diversity between the different IPE
               The results were that .95 target reliabilities
     were generally met with and without MOOS, which is
     maintenance and testing out of service while at power.  And
     what this accounts for is, if a licensee takes a diesel out
     of service while the unit is running, and then has a loop,
     loses voltage to the bus and it's called into service, then
     that would be counted as a demand and that would count
     against them.  We'll get into that a little more pretty
     quick here.
               And the .975 target reliabilities, the MOOS had
     risen to levels that many or most of the licensees were not
     able to meet the .975 target considering MOOS.
               We've done a -- there is another NUREG available
     which looked at the risk significance of MOOS, and basically
     it was based on six IPE PRAs, a sample.
               And it shows that less than two percent MOOS is
     likely not to have much risk impact but values between 02 to
     04 could be risk significant in that they would cause
     changes on the order of ten to the minus five to the risk.
               What I also did was, I took the three lowest
     values from the INEL report and did a followup at the plant
     sites to find out that when we think or we're saying the
     reliability is less than .95, they think it's .99, and I
     identified some differences in the scorekeeping here that we
     need to clarify.
               Basically, this report, the INEL report, is based
     solely on actual safety demands of the diesel while in
     service, and the annual tests where you actually run the
     diesel through its full pace.
               So it's based on those demands and starts.  And
     you would expect that if -- well, you would expect the plant
     site numbers to be equal to those numbers, and there are
     some different methods of scorekeeping going on that need to
     be addressed.
               The INEL report also shows that many licensees
     have achieved higher diesel reliabilities than used in their
     IPE PRA, so if they were to plug those numbers into their
     IPEs, they would obtain additional risk benefits.  There is
     some unclaimed risk benefit from the station blackout rule
     that we have yet to -- you have to recognize that it is
     there, but it hasn't been claimed yet.
               In the comment cycle for the internal comment
     review, there was considerable discussion on what was the
     diesel performance basis.  So what I did was to address all
     those concerns.  There is two sections of the report that
     pretty closely plagiarized what is in the Reg. Guides, with
     specific reference to the section, so there is no question
     about what is said.  And then I go on to show, to point out
     the conflicts between those individual sections.
               You have NUREG-1032, which is the technical basis
     of the station blackout rule, and that established that MOOS
     was small, both at power and non-power, it was .006.  It
     established -- it used the diesel, or the emergency power
     system boundary to include the load sequencer and the bus,
     and it only used -- and it used actual tests and unplanned
     demands to count valid start load runs.
               Then we get to Reg. Guide 1.15, establish the
     target reliabilities, and, specifically, in the discussion
     it excludes MOOS, but it points out that it is small and it
     used .007.  And it specifically addresses that this is small
     compared to the reliabilities expected in the regulatory
     position.  It says, however, this can be significant.  It
     goes on to say the contribution must be kept low.  And then
     they had the vision to say that as long as the
     unavailability due to testing and maintenance, that is MOOS,
     that is my words, that is MOOS, is not excessive, the
     maximum EDG failure rates for each diesel specified would
     result in overall acceptable reliability.  And the fact of
     the matter is, it is not -- the amount of it is not small. 
     I would think we appropriately considered it in the
     reliability assessment.
               And then the Reg. Guide also uses NUMARC 87.01,
     which requires or stipulates that the licensees monitor EDG
     unavailability versus the industry, and they have been doing
     that since 1989, and that is available as an industry PI.
               Then we get into the station blackout rule, which
     gives you several alternatives.  The point being there that,
     with the exception of the Reg. Guide, target reliability,
     all those other alternatives could be non-conservative with
     respect to risk, and you could erode the risk benefits
     obtained from the station blackout rule.  So, there is
     nothing in there to cap how much unavailability you can
     have, there is nothing in those Reg. Guides that say how do
     you balance availability and reliability and unavailability. 
     And then maintenance preventable failures is a different
               It also endorses -- 
               DR. BONACA:  Could you explain this balance
     reliability, the unavailability?
               MR. RAUGHLEY:  In the discussion, the maintenance
     rule has three basic elements.  It has got A-2, which is
     performance criteria; A-1, which is if you don't meet the
     performance criteria, you go and establish goals under A-1
     to get your performance back up.  And then A-3 says that you
     should balance reliability and unavailability.  And there is
     not much detail on how to do that.  
               So we know from 1032 and the licensee IPE PRAs,
     you know, the decreased reliability or increased
     unavailability erode the risk benefits.  So, you have got,
     if you are going to give up one, then you have got to raise
     the other.  And that detail is not there, which could cause
     licensees to erode the diesel reliabilities.  So that is the
     point of that slide.
               And then there is additional requirements.  Reg.
     Guide 1.93 was revised as part of GSI 56 resolution, and it
     says the start and load run failures should include
     conditional failures from maintenance, and nobody has -- you
     go out and do maintenance, and you find the problem, you
     don't generally count that as a failure.  That is why you
     are doing the maintenance and testing is to identify the
     problems and fix them before they happen in service.
               And the system boundary there excludes the load
     sequencer and the bus.  That was a point of discussion in
     the review, that the INEL study included the load sequencer
     and some people believe that it shouldn't.  However, the
     load sequencer, you need the load sequencer for the diesel
     to perform its safety function.  It starts and load the
     diesel, keeps it from being overrated.
               DR. POWERS:  It seems like we have had recent
     events where the load sequencer -- 
               MR. RAUGHLEY:  Yeah, there is six events, I
     believe, in the INEL report where the load sequencer failed,
     and that influences the reliability.
               And then the last, but not least, is that the SBO
     and maintenance rule inspection documents introduced another
     performance standard in that they required inspectors to go
     out and verify compliance to the target reliability used in
     trigger values.  And that was a considerable -- statistical
     wars I guess went on between the ACRS and the industry from
     1988 through 1992.
               DR. SEALE:  That is Hal Lewis.
               MR. RAUGHLEY:  Yes.  And Med helped me dig out the
     correspondence from that and Appendix D provides that the --
     from what we can make there.  The ACRS was using the
     binomial theorem and coming up with failures and demands to
     assure with high confidence that the reliability goals were
     met.  And the industry's position, or the industry used the
     binomial theorem to develop failures and demands to assure
     with high confidence that it didn't meet the goal.  They
     didn't think -- 
               DR. POWERS:  I would love to tell Ray, tell
     that -- 
               MR. RAUGHLEY:  Yeah.  So, finally, the EDO issued
     a memo and that specifically says the triggers do not in any
     statistical fashion demonstrate the target reliabilities. 
     However, unfortunately, they crept back into the inspection
     procedure, so that is what we have been inspecting to.
               The other point of the ACRS at the time was that
     if you used the industry values, you would be waiting for
     long periods of time before you identified problems, and
     that is not consistent with maintaining high reliability. 
     If you think you have got a problem and you investigate it
     and you find out it was a no-never-mind, that is the way you
     assure reliability, you know, and go about it in a timely
     fashion rather than waiting for the score to go bad.
               And then if you also, if you use those trigger
     values and superimpose those on the information in the INEL
     reports, you would clearly be outside the IPE PRA bounds for
     the six and eight hour -- the diesels with six and eight
     hour emission times.  So you would clearly erode the risk
     benefits using those.
               DR. BONACA:  Just before we leave that point, I
     mean you had two slides there, and essentially, it seems to
     me that meeting the reliability targets is really central to
     the station blackout success.
               MR. RAUGHLEY:  Yes.
               DR. BONACA:  And what you are saying, you have the
     guidance resulting from, you know, multiple Reg. Guides and
     rules, et cetera, it is confusing enough that it is not
     clear what the licensees are measuring to demonstrate they
     are meeting their reliability targets.
               MR. RAUGHLEY:  Yes.  Yeah, we have got a half a
     dozen different documents, all addressing diesel
     reliability.  They need to revised in a consistent manner.
               DR. BONACA:  And you are going to give use an
     estimate of the amount of erosion of the 3.2 and 10 to the
     minus 5 that you expect to happen from this variation,
               MR. RAUGHLEY:  I put two tables in the report.
               DR. BONACA:  That's right.  Yes.  Okay.
               MR. RAUGHLEY:  To show how much it would erode.
               DR. BONACA:  And I would appreciate it if you can
     tell us how do you estimate that erosion.  Could it be more
     than what you are looking at here?
               MR. RAUGHLEY:  Yeah, it would be more or less,
     depending on what your case CDF is.  If you are SBO CDF is
     10 to the minus 6 or 10 to the minus 7, it is not likely
     that the diesel reliability is going to make a whole lot of
     difference, but there are a number of plants, I believe, --
     well, there is about half that have SBO CDFs in the 10 to
     the minus 5 range and changing the diesel reliability would
     affect those.  And what I did was I extracted information
     from NUREG-1032, went through the different permutations and
     combinations of things, Table 3 or 4 in the report.  It
     shows you at what point it could become important.
               DR. BONACA:  All right.  Thank you.
               MR. ROSENTHAL:  Let me just interject, because I
     want to make sure that we, at least in my mind, that we have
     right tonal quality.  From the reliability studies, much of
     that comes out of Pat Barnowski's branch, that you have been
     briefed on separately, those are studies where you drop a
     wrench on an electrical bus in the middle of the night, and
     you ask, do things really start and load and power-actuated
     equipment?  You know, not the monthly stylized tests.  So I
     think that that is real good data industry-wide on how good
     the diesel system is.  Of course, the data density is
               DR. BONACA:  Right. 
               MR. ROSENTHAL:  Okay.  But from that work, it says
     that, at least on an industry-wide basis, including MOOS, we
     are meeting the .95.  So I don't want to be -- from a safety
     standpoint, we think that you are meeting the safety
     objective.  There is some question on the 975.  But we are
     meeting the 95.  And we have good, experimental basis for
     saying that on an industry-wide average basis.  So we don't
     want to be overly shrill.  Safety-wise, I think we are okay.
               But what we are saying is, wait a minute, there is
     all this guidance out and here is an opportunity to clear
     up, to clean up the regulatory bases documents consistent
     with the principles of good regulation.  But I don't want to
     leave the impression that we are sitting here saying that we
     have an imminent safety problem, because we don't.
               DR. BONACA:  Yeah.  No, I didn't mean that.  It is
     just simply that the impression I got is, given the fact
     that this was a costly rule, in fact it cost four times as
     much as was supposed to be invested, I mean, you know, you
     certainly don't want to squander this other benefit from
     this costly rule implementation, invaluable rule
     implementation, by having confusing guidance.  And we have
     noted that issue on confusing definitions of availability
     and reliabilities in other reviews.  And, certainly, I just
     wanted to ask that question to make sure that was the
     message you were giving us.
               MR. RAUGHLEY:  Yes, sir.  Some of the insights
     from the operating experience review is some of the
     modifications from the SBO rule have been used specifically. 
     I put an example in there on Turkey Point.  Originally, they
     had two diesels, two safety-related diesels and five non-
     safety diesels shared between two plants.  As a result of
     the station blackout rule, they added two safety diesels. 
     During an event subsequent to the addition of those diesels,
     they lost all five non-safety diesels and one of the two
     original diesels.  So, had they not made the mod, they would
     have been reduced to one diesel.
               The information in the NRC inspection report shows
     that the load running on the remaining diesel would have
     been about 20 percent more than its rating.  We could debate
     whether it would have burnt up or not, but likely it would
     have.  And you realize in that condition, all the protective
     features are bypassed because the philosophy is you run the
     diesel till it does burn up.  So, fortunately, so I think
     you can hold this up as a shining example of a case where
     the SBO rule did a lot of good.
               In addition, their initial analysis, Turkey
     Point's initial analysis showed that the SBO CDF was on the
     order of 10 to the minus 4 and, as a result of adding these
     diesels, they were able to reduce it to 10 to the minus 6. 
     And the proof was in the pudding.
               And several licensees, there were 19 non-safety
     diesels added, they have provided many licensees with
     increased allowed outage times and replacement power
     benefits.  So there has been some economic benefit, if that
     is important.
               As far as the LOOP, there are favorable trends on
     the LOOP frequency and duration.  They are documented in
     NUREG-5496, which looks at the operating experience from
     1980 through 1996, and there haven't been many LOOPs since
     then either.  But I think the important point there is -- I
     looked at all the events where restoration took more than
     four hours.  For the plant events, we noted in a report that
     the number of plant events more than four hours was up from
     zero to four, but the recovery time stayed about the same,
     about 20 minutes.  For the grid events, the recovery times
     increased from 36 to 140 minutes.  And for the weather-
     related events, the recovery times decreased from 4-1/2
     hours to 2-1/2 hours.  
               But I think the point of all the LOOP, what we see
     there is that the diesels worked when they were actually
               The other insights, I think the station blackout
     rule provides some defense-in-depth to deregulation of the
     electric power system.  We don't have a whole lot of control
     or say on how that goes, but should the LOOP initiating
     frequency increase, or take longer to restore power, there
     are additional benefits there from the hardware that was
               And then one thing we did find in looking at the
     events, we identified four events where there is the
     potential unavailability of the alternate access power
     supply when it was needed.  There were AC and DC
     dependencies on the unit that was down.  There was an IN
     issued on it, but there have been events subsequent to that. 
     So maybe we need some things in the inspection, attributes
     in the inspection procedure to address common mode failure. 
     The NUMARC document that I mentioned earlier, 87001, has
     specific guidance that could be used as inspection
     attributes in that area.
               So, our overall conclusion was that the rule was
     effective and the costs were reasonable because the
     reliabilities were achieved, the risk reduction was
     achieved, most of the licensees -- or all the licensees
     picked four hour or eight hour coping times.  But there are
     opportunities to improve the clarity of the Reg. Guides, and
     this would be consistent with the principles of good
     regulation.  In the area of reliability, there is the Reg.
     Guides that we went through, but they need to be revised in
     a consistent manner so we put the reliability terms on an
     equal footing.
               Just to recap those, you have MOOS, you need to
     include the load sequencer in the boundaries, address how to
     balance reliability and availability, and establish common
     start load run criteria.  The inspection documents, you need
     to delete the use of the trigger values and provide some
     guidance on the common mode failure inspections.  And in the
     Reg. Guide 1.93, which addresses the -- requires shut down
     with less than the number of power supplies, there may be a
     better way to go about that.  For example, you might want to
     check the availability of your coping systems before you do
     something like that.  You might want to check that the grid,
     you know, that when you shut the unit down, that the grid
     are able supply sufficient capacity shutdown loads.  Maybe
     shutdown is not the right spot, maybe how shutdown is the
     right spot, but I think we can improve that.
               As a Lesson Learned, I think as a result of seeing
     how the station blackout diesel reliability, addressing it
     in the station blackout rule and the maintenance rule, what
     it could have been done back then is when we issued the
     maintenance rule, when we issued one piece of regulatory
     information maybe go back through to make sure everything is
     consistent.  It doesn't appear that there is a good process
     to do that, but we are about to go through some major
     changes to the regulatory documents to make them risk
     performance based and to the extent that we do that we need
     to be sure that we used terms, goals, criteria and
     measurements consistent with it we are going to have to go
     back, I think it would be wise to go back and make sure we
     don't undo anything like the station blackout rule as we
     revise on future revisions to the documents.
               Your response?
               MR. SIEBER:  I have a question that is sort of a
     summary question.  When you look at expectations and cost,
     you found that the actual risk reduction achieved was
     slightly better than the expectation that the rule
     envisioned when it was issued, but the cost -- NRC's
     original estimate was $60 million and the actual cost to the
     industry was $230 million, which is almost a factor of four.
               MR. RAUGHLEY:  $175 or $180 million to the 19
     power supplies.  We did not anticipate that at all.
               MR. SIEBER:  But nonetheless the SBO rule prompted
     licensees to change those power supplies.  Is that correct?
               MR. RAUGHLEY:  Yes.
               MR. SIEBER:  Okay.  Does the utility industry
     agree that the costs for the SBO rule were reasonable?
               MR. RAUGHLEY:  It is out for their comment.
               MR. SIEBER:  Okay.  
               MR. RAUGHLEY:  You could debate that.
               MR. SIEBER:  I would prefer not to debate that
     here, but I just wanted to know whether, since you state
     that it was reasonable, if the people who spent the money
     think it was reasonable too, and I guess the answer is you
     won't know until somebody tells you.
               MR. ROSENTHAL:  But we specifically sent it to
     NEI, EPRI, INPO, et cetera, asking for their comments.
               DR. BONACA:  The other thing is in the evaluation
     we have to recognize some licensees chose to buy diesels
     because they were useful for other purposes too.  They could
     have chosen to address the rule without purchasing that, so
     in the cost benefit you will have to eliminate those made
     their own choice, address it that way.
               I know of some sites that had options --
               MR. SIEBER:  That might have happened in a couple
     of cases but I remember our budgets didn't allow for those
     kinds of things.
               MR. RAUGHLEY:  We're trying to look at things,
     simple things we can do to make us better regulators in the
     Lessons Learned, and belaboring sunk costs in the future is
     kind of -- I don't know the relevance of that.
               CHAIRMAN POWERS:  Well, the only relevance that I
     can think of for future would be is there something
     inherently flawed in your estimation, cost estimation
     process?  The only thing that comes to mind is that there
     are going to be ancillary thinking about what is
     purchased -- (a) with the appearance of cost of a specific
     rule up and then how you split those out if you are going to
     do a cost benefit backward analysis on this is kind of a
     difficult thing.
               You say the guy could have bought a wagon and
     instead he chose to buy a railroad car, for other reasons,
     how much of that railroad car actually applies to the rule? 
     That is a tough one to figure out.
               MR. SIEBER:  I guess the only reason I bring it up
     is I recall other cost benefit analysis that sort of had the
     same result.  NRC Staff sometimes comes up with a lower
     number than the actual cost to the utility and so the
     question is is your estimation process effective in some
               DR. WALLIS:  In the introduction Jack talked about
     the goals of the Agency, one of which I believe is to
     maintain safety.  It seems here that you have actually
     improved safety, which is what the Europeans prefer to use
     as a goal, rather than maintaining safety.
               In the present climate the move seems to be to
     maintain safety and reduce the burden.  Here you have
     actually improved safety and you have actually increased the
     burden, but you still have done a good job, so it just seems
     to me that, I am just pointing out that it seems to me a
     slight difference between taking literally the goals and the
     actual implementation here.
               CHAIRMAN POWERS:  I think that here's one where a
     risk analysis had clearly pointed to a vulnerability the
     plants had and it passed the backfit argument.  I mean it is
     a real regulatory success basically.
               DR. WALLIS:  Oh, it is.  It's fine, but some
     lawyer might say, hey, you are only supposed to maintain
     safety, not improve it, what are you doing?
               CHAIRMAN POWERS:  I think we would probably ask
     that lawyer to go look at the Atomic Energy Act.
               DR. WALLIS:  I am in favor of that --
               DR. BONACA:  I have a question regarding this is a
     draft document.  Will the report include a recommendation
     regarding cleaning up guidance documents like Reg Guides and
     so on and so forth, or will it just be moot and say there
     are opportunities there and let's face them.
               MR. ROSENTHAL:  Of course, we are receptive to
     your input.  The current plan would be to stop the report at
     the conclusions and then to have a cover letter or
     transmittal memo which would contain the recommendations and
     it's not clear to me -- the current plan is that Ashok would
     be sending it to in this case NRR.  The Commissioners,
     single Commissioners have expressed an interest in this
     report as a prototypical document, so I am sure that we are
     also going to be communicating with them.
               We intend to have recommendations and intend to
     follow up on the conclusions but I think that it will be in
     the transmittal memos.
               DR. BONACA:  The next question I have, regarding
     that, is that if you had to provide a recommendation for
     providing consistent guidance to all licensees on how to
     meet their reliability target or how to measure in order to
     demonstrate meeting reliability, would you recommend to have
     a new document do that or just simply going back and making
     all the previous -- the question I am asking is because you
     have all these Reg Guides and NUREG and rules with
     inconsistent data.  
               I have no appreciation for what it takes to change
     all these rules and that may be -- what would you recommend?
               MR. ROSENTHAL:  We haven't thought through the
     mechanics.  The goal would be to go to, and the thing that
     makes most sense to us is to have reliability goals where we
     have good definitions for reliability.  It is consistent
     with the way the Agency is going.  We clean up the issue of
     maintenance out of service in that reliability goal.  You
     know, RES is pushing to go from performance indicators that
     look at unavailability, which is what we are doing now, to
     looking at reliability.  
               If we could get agreement that what we ought to be
     looking for is the reliability and assure that reliability
     is consistent with what is in, presumed in the IPEs, then we
     have to go back and clean up the documents.
               How we would clean up the documents we have not
     thought through.
               DR. BONACA:  The easiest way would be to have
     white paper that says in meeting these targets this is --
     and really that could quote the work done by E&L as a
     means -- it would provide a standard for everybody to
     follow.  I believe the industry would welcome a standard
     other than branching out and trying to figure out what they
     have got to do and then coming up with numbers which we
     claim are inconsistent with that.
               MR. ROSENTHAL:  But at a minimum Hal Lewis does
     deserve at least a footnote that says, hey, he really was
     right, and we --
               DR. KRESS:  Don't say that too loud.
               MR. ROSENTHAL:  -- and to change what we tell our
     inspectors to look at.
               DR. BONACA:  And it is a problem a white paper
     would not resolve, because still there is a guidance there
     in the field that says --
               MR. ROSENTHAL:  Right, so we are arguing that we
     ought to, that this is an opportunity to clean up the
     regulatory process and make it more coherent and consistent.
               DR. BONACA:  Another question is is the issue
     significant enough that it deserves that kind of action, and
     I don't know.
               I have two opinions.  They are personal opinions.
               One is even if quantitatively there may not be a
     significant impact, qualitatively it is a problem to have
     incoherent items in documentation.  So I just wanted to get
     a feeling from you and then from other members regarding
     that issue, because then we have to make a decision here,
     which is are we going to write a letter report on this, and
     I would like to hear also from Mr. Rosenthal what you expect
     from us.
               MR. ROSENTHAL:  We are conferring as we speak
               DR. BONACA:  Okay.
               MR. ROSENTHAL:  Officially we came to provide it
     for information to the ACRS so the choice would be yours.  
               My new Acting Division Director and I were
     whispering at each other letters are always welcome or
               DR. SEALE:  And that is a sage hand that made that
               Could I make one other point?  In your initial
     comments you made the observation that the station blackout
     rule had very in many cases plant-specific impacts.  That
     is, all plants were not the same, that the influence of the
     station blackout rule varied considerably from one plant to
               One of the concerns I have is that when you get
     your response back to be specific to just make the point,
     are you going to get a Florida Power response or are you
     going to get a -- what is the other one? -- St. Lucie or are
     you going to get a Turkey Point response?
               The Turkey Point response based on what you said
     is going to likely say some very specific things that might
     not be said if you had a homogenized response.  I hope it
     will and it strikes me that it would be very worthwhile in
     your review of the comments that you could somehow bring our
     attention to those facts or those things which were
     different from plant to plant and see whether or not the
     comments you get reflect those differences because, you
     know, if you make the room dark enough all cats are gray,
     and I don't think that this is a homogenous issue for all
               DR. UHRIG:  It is also related to the era in which
     they were built. 
               DR. SEALE:  Of course.
               DR. UHRIG:  Turkey Point was built in an era --
               DR. SEALE:  The regulatory climate was very
               DR. UHRIG:  Later on they would never been allowed
     to have two diesels for two plants.
               DR. SEALE:  That's correct, and that is one of the
     problems with the station blackout rule. That is, you have
     to make this homogenous assessment which doesn't mean the
     same thing for every plant.
               MR. RAUGHLEY:  In the Reg Guide that accompanies
     the station blackout rule it has got eight tables, one
     recognizing five different severe weather categories, so a
     plant located on the East Coast would be driven to pay more
     attention to this than a plant in Arizona because of the
     severe weather conditions.
               It recognized the different power system
     configurations, where there are two lines, one line.  You
     know, how are you counting the offsite power supplies that
     you have?  Some people count the unit output.
               DR. SEALE:  On the other hand, the Secretary of
     Energy has just come out this last week with a warning that
     the plants, particularly in the Southwest and the Northeast,
     are going to be particularly vulnerable to grid system
     unreliabilities because of high heat loads this summer, and
     that is not in there I don't think.
               MR. SIEBER:  On your last slide where you talked
     about Lessons Learned, I think you have one there that you
     have listed, but I think an important one was one that was
     said right in the beginning, which is the analysis, the
     regulatory analysis was simplified because the expectations
     were explicitly and clearly stated when the rule was
               I would think that a Lesson Learned would be in
     new rulemakings to specifically identify and state what the
     expectations are for that rule so that you can do an
     analysis and determine after it has been in effect for
     awhile whether you have achieved the expectation or not, and
     that to me is another part of performance-basing.
               DR. SEALE:  Gets you out of the feel good
               MR. ROSENTHAL:  I have to actually compliment
     Bill. He has been a regulatory archeologist where you go to
     the rule.  If it is not in the rule you go to the statement 
     of considerations.  If it isn't there you go back to a
     supporting NUREG or the NUREG to the NUREG and then the
     NUREG CR that backed that up, and always looking for
     something that is public and documented, but it has been
     quite a dig, and as he said earlier, ATWS is not as clean a
               I think we probably chose the cleanest one.
               MR. SIEBER:  I was just remarking that I think
     that the fact that that is a Lesson Learned and it is
     something we should be doing in the future.
               DR. BONACA:  Any other questions?
               [No response.]
               DR. BONACA:  Before we adjourn, I would like to go
     around the table, since we had no --
               CHAIRMAN POWERS:  Want to do that off the record?
               DR. BONACA:  All right.
               CHAIRMAN POWERS:  I'll take us off the record.
               DR. BONACA:  They I will pass it off to you, Mr.
               CHAIRMAN POWERS:  Any other comments people want
     to make about this presentation?
               [No response.]
               CHAIRMAN POWERS:  Fine.  At this point we can stop
     the transcription until this afternoon, and I want to go and
     discuss the first two presentations we have had and receive
     any comments the members would like to make as guidance to
     authors or potential authors.
               Thank you very much.
               MR. ROSENTHAL:  Thank you.
               [Whereupon, at 11:30 a.m., the meeting was
     recessed, to reconvene at 1:00 p.m., this same day.].                   A F T E R N O O N  S E S S I O N
                                                      [1:05 p.m.]
               CHAIRMAN POWERS:  Let's come back into session. 
     Members have before them, a list of potential issues that
     might be associated with review of an AP-1000 design for
               I hope you will take the chance to look this over,
     make any comments on the list, and get it back to us.  We
     are obligated to provide the staff with some indication of
     the kind of topics that we would want to look into if this
     certification does come to pass.
               And I'd like to get that letter over to the Staff
     this week.  
               Okay, at this point we'll turn to the next item of
     business, which is the Regulatory Guide and whatnot
     associated with the revised source term rule.  And, Dr.
     Kress, I guess this, too, is one of your areas of expertise.
               DR. KRESS:  Yes.  You will recall that previously
     the Staff worked on a rule to allow the voluntary use of
     alternative source terms based on all the information we
     knew, and the NUREG 1465 source terms that were developed as
     a result of this new information.
               We wrote a letter -- I forget the timing on that,
     but it wasn't too long ago -- commending the Staff on what a
     good job they are doing in determining all the ramifications
     of the use of the new source terms, and what risk
     implications there might be and things.  
               Well, they now have issued the rule for public
     comment, and they have also developed a Reg Guide and a
     Standard Review Plan to go along with the rule, and have
     issued it for public comments and received the comments
               And we saw a draft of that, but we didn't review
     it, I don't think.  I don't recall whether we reviewed the
     earlier draft or not.  But at any rate, what we have before
     us is the final version, basically, of the Reg Guide and the
     Standard Review Plan.
               Before they go up to the Commission and say we
     want to issue this in final now, they'd like our comments
     and perhaps a letter as to what we think about it.
               They did make some changes over the draft that we
     may have seen, and some of these changes are noted in your
     package.  They have to do with gap fractions, chemical forms
     of fission products.  There is a list of them here that you
     can read.  There is no use in my going over them, because I
     think the Staff intends to pretty much highlight what these
     changes were over what we've seen before.
               So, with that as a really quick introduction, I'll
     just turn it over to the Staff.  
               MR. LaVIE:  Good afternoon.  I'm Steve LaVie with
     the NRR, Probabilistic Safety Analysis Branch, which, as you
     may be aware, also picked up the dose assessment people in a
     recent reorganization.
               As Dr. Kress pointed out, I'm going to present to
     you, the changes that have occurred in the guidance
     documents we prepared for the implementation of the
     alternate source term.
               Dr. Kress gave you a little bit of the background,
     and let me touch a couple of the points again.  You may
     recall that we've been before the Committee several times. 
     Back in 1998, we prepared a rulemaking plan which you folks
     provided us comments on.
               And we also at that time presented the results of
     the baselining study.  As a result of that rulemaking plan,
     what we recommended to the Commission and that the
     Commission endorsed, was to go prepare a rule change and
     also a new Regulatory Guide, and, of course, a Standard
     Review Plan section to support that Regulatory Guide.
               This is the path we've taken.  We haven't deviated
     from that too far.  In March of 1999, we published the draft
     rule in the Federal Register for public comment.
               In December of 199, we published the final rule in
     the Federal Register.  That rule became effective in January
     of 2000.  
               At that time we included an announcement of a
     public comment on the draft guide.  We did provide the draft
     guide as part of the final rule package to the Committee. 
     That would have been in the September/October timeframe in
               As I pointed out, the final rule became effective
     on the 24th of January, and the public comment period that
     ran for 75 days, ended at the end of March.
               We received numerous comments, six official
     letters from the Nuclear Energy Institute, the Nuclear
     Energy Environmental Qualification Group, from Duke Energy,
     Virginia Power, South Texas Project Nuclear Operating
     Company, and the Florida Power Corporation.  
               We also received numerous informal comments by e-
     mail and other approaches.  People came up to us and so
     forth and made a comment, and we attempted to address all of
               We also addressed the ACRS recommendations that
     you provided to us in the October 1999 letter.  There were a
     total of 138 comments, several of which were redundant, but
     nevertheless, we had some things to look at.
               Now, we dispositioned all those comments we
     received.  I provided in the package, and you should have,
     the disposition of the comments we did receive.
               What I'm going to discuss this afternoon is the
     significant changes that we made that would change the
     technical content and a couple of policy items.
               These are categorized, basically, into the areas
     of fuel gap fraction; fuel handing accident chemical form
     for the release; selective implementation; 50.59 guidance. 
     As you may be aware, 50.59 guidance was being prepared in
     parallel with this effort.  We have had to go back and
     adjust a little bit for what's proceeded in that process.
               And there were several other smaller technical
     changes which we'll go over quickly.
               Perhaps the most significant change we had, had to
     do with the fuel gap fractions.  In the draft guide, we had,
     in essence, stayed with the traditional values we had been
     using in licensing for several years.
               The industry provided us with several comments on
     this, both formally and informally, to the effect that we
     needed to do something different.
               And the industry suggestions can be summarized as
     that they suggested that we have gap fractions that would
     vary from three percent at 50 gigawatt days per metric ton
     uranium, to 9.3 percent at 75 gigawatt days per metric ton
     of uranium.
               DR. KRESS:  Is that based on the experimental
               MR. LaVIE:  It was based on some experimental
     data, results of fuel sipping on fuel that has been
     irradiated in plants to date.  It was largely based on an
     EPRI report, that EPRI had looked at this issue.
               The industry had extrapolated that data to make
     the recommendation.  
               DR. KRESS:  Extrapolated it to 75?
               MR. LaVIE:  Yes.  They had no experimental data
     above 65.  
               DR. KRESS:  That's interesting that you end up
     with 9.3, which is four significant figures because it's a
               MR. LaVIE:  Right.
               DR. KRESS:  For something that's extrapolated.
               MR. LaVIE:  There is a large amount of uncertainty
     here, yes.  
               They also suggested that we allow the licensee to
     vary the gap fraction across the core.  This hadn't been
     something that we had given a whole lot of thought to
     before, but we were able to come to some agreement on that
     for some accidents.
               And they also suggested that we address the fuel
     heatup impact separately.  This would largely address
     accidents such as the reactivity insertion accident.
               Now, when the Staff looked at this comment -- of
     course, we had to consider it even before we published the
     draft -- is, we just felt there was insufficient data to
     support iodine gap fractions above 65 gigawatt day metric
     ton uranium.  There was insufficient data above that point.
               Now, the industry data they presented to us was
     largely the result of low burnup data that had been
     collected over fuel that's been burned to date.  The
     majority of the data was much less than 50,000 and very few
     points above.
               There are large amounts of uncertainty in these
     gap fractions, as you may be aware of.  The data they
     presented was based on actual fuel, and as such, they did
     not have the operational transients that could occur during
     operations and still be within the fuel limits.
               The current fuel management that's being used
     today in power plants is far more aggressive than that under
     which the data was collected.  A lot of this data was
     historical and, say, maybe five-ten years old.  We have much
     more aggressive burnup regimes right now, so there was
     uncertainty involved with that.    
               The biggest problem we had is, in the majority of
     experiments that had been done to date, iodine has not been
     measured directly.  Iodine has always been inferred from
     some other measurement.
               DR. KRESS:  You don't get a gamma.
               MR. LaVIE:  Right.  It's been done through
     thermodynamic correlations, ratio of the diffusivity of
     noble gases to iodine, which is the basis of the ANS 5.4
     method, with a great deal of uncertainty.
               So, we went into this comment with the idea of
     what can we do about this?  While we did see all these
     uncertainties, we also had this feeling that based on some
     of the data we were looking at, that perhaps we were high on
     gap fraction.
               DR. KRESS:  The gap fractions you had been using,
     taking actual fuel and cutting it open -- 
               MR. LaVIE:  Right, back in 1960 or sometime.  They
     were first documented in Reg Guide 125 for fuel handling
     accidents, based largely on work done by Westinghouse. 
               So we needed to come up with an approach for this. 
     Recognizing this is a deterministic design basis proceeding
     with this Regulatory Guide, we decided we would use the
     NUREG 1465 data for the LOCA, for the gap fraction part of
     the LOCA, gap phase, and we would allow that to be used for
     ranges zero to 62 gigawatt day per metric ton uranium.
               DR. KRESS:  Let me -- associated with that, when I
     read the Reg Guide, you also decided for the gap fraction,
     that you would use the NUREG 1465 speciation for iodine.
               MR. LaVIE:  That's correct.
               DR. KRESS:  That strikes me as a little strange. 
     You're saying that in the gap, the iodine consists of 95
     something percent of cesium iodide, a certain fraction of
     elemental iodine, and a certain fraction of oriatic iodine.
               But the NUREG 1465 values came out of chemical
     effects after the stuff got out of the fuel, and it
     certainly did not imply that gap had these, and, in fact,
     all the data I know of about gap fractions chose the cesium
     iodide as primarily -- I mean, the iodine is primarily
     cesium iodide.
               MR. LaVIE:  That's correct.  
               DR. KRESS:  And so I don't think it makes much
     difference in what you apply or use the gap fractions for,
     and it doesn't change the gap fraction; it changes the
               MR. LaVIE:  Right.
               DR. KRESS:  And it's such a small amount of
     iodine, I don't think it makes much difference, but it
     seemed a little strange and inconsistent with the technical
               MR. LaVIE:  True.  I don't disagree.  For the
     LOCA, as you point out, it's really not a large consequence,
     because you're looking at five percent of the total core
     inventory, which is immediately going to be followed by the
     other 95 percent of it.  
               So it's not going to make a lot of difference for
     the LOCA.  Now, when we went to the other accidents, there
     was no data for what was in the gap.  
               However, we looked at the NUREG -- I want to say
     737, but that's not correct.  NUREG 0772 had the data that
     showed that what was in the gap was predominantly cesium
               DR. KRESS:  That's the only evidence.
               MR. LaVIE:  So we felt, you know, throwing in
     elemental made it a little bit more conservative, because we
     are in deterministic space here.
               DR. KRESS:  Yes, it certainly wouldn't hurt.
               MR. LaVIE:  It wouldn't hurt, and then the
     conversion gets us the organic.  We used the same conversion
     ratio that was specified in 1465.  We believe that's
     conservative and reasonable for this deterministic approach.
               DR. KRESS:  You're just saying that once you use
     this fraction for whatever you're using it for, you probably
     ought to be conservative and assume some of it got to be --
     so it doesn't -- 
               MR. LaVIE:  Our intent was to be conservative,
     because we really -- there is -- all the research and data
     has been done on the LOCAs.  Now, the risk-informing -- 
               DR. KRESS:  Now, the real problem is that those
     values for the LOCA, for the early in-vessel release, come
     out of very specific considerations.
               MR. LaVIE:  Right.
               DR. KRESS:  And what they were was, you look at
     the whole spectrum of accident sequences, and what happens
     is, you release the cesium and the iodine and the chemical
     reactions in the gas phase create cesium iodide, but part of
     the -- during part of the sequence, you're steam-starved and
     you're hydrogen-rich, and during that part, you get a
     certain amount of hydrogen iodide, which we called something
     different than a cesium iodide.
               And then there was a certain amount of organic
     iodine that always gets produced because there is some
     organics in there, too.
               MR. LaVIE:  Right.
               DR. KRESS:  And these were the three values, the
     maximums in any of the sequences, and they used them in the
     NUREG 1465 as bounding values.  And it all happened because
     the chemistry effects in the downstream of the core after it
     got released, none of those chemical effects are going to
     happen when the gap gets released.  
               The concentrations are different, the temperatures
     are different, and they're always steam-rich when the gap is
     there.  So there's no reason to expect the NUREG 1465 in-
     vessel release speciation to be the same in the gap.
               And I would have gone -- like you say, it's
     conservative and doesn't make any difference, probably, in
     what you do, but I would, just for consistency's sake, not
     had that kind of -- you know, it just looks funny in Reg
     Guide to have something that doesn't have any technical
     basis at all.  
               And so that's my concern.  My concern is not that
     it's there and will cause anybody any problem, because I
     don't think it will, but it's just a coherence, consistency
     type of problem.
               MR. LaVIE:  Right.  Am interpreting what you are
     saying correctly, that you would prefer to have seen us
     specify that it was all cesium iodide?
               DR. KRESS:  I would have just kept it the way it
     was in the old Reg Guide, frankly, for the gap.  You had a
     speciation in there, and it was 99 -- 
               MR. LaVIE:  99 percent elemental, I think.
               DR. KRESS:  I'm sorry, I would have just called it
     cesium iodide.
               MR. LaVIE:  Okay, see, in the original draft, we
     called it elemental, 99.75 percent elemental.
               DR. KRESS:  I wouldn't have done that, because the
     evidence is that it's cesium iodide in the gap, and I would
     use that.
               MR. LaVIE:  And we thought this was a reasonably
     conservative compromise with considering the deterministic
     design basis approach we're dealing with here and would be
               DR. KRESS:  I would agree that it is, but it just
     looks funny when you use an inconsistent technical basis to
     establish your conservatism.  But I agree that it's not a
     big deal.  
               DR. LAVIE:   We continued with the protocol we had
     in the draft guide, using the Reg. Guide 1.77 data for
     reactivity insertion accidents.  As you're all aware,
     there's a great deal of work going on right now about the
     reactivity insertion accidents because of the Cabris results
     and the lack of beta data to change.  We're holding the
     status quo on the reactivity insertion accidents, so they'll
     continue to use the gap fractions from the old data.
               Now, we had some work done by PNNL to address the
     environmental impact of the fuel burn-up from 60 to 62
     gigawatt days per metric ton uranium.  And that data became
     available during this period.  It is being documented as an
     update to the NUREG CR-5009.  
               Now the PNNL analyses were done for core average
     and the peak rod average at 35, 60 and 65 gigawatt days
     metric ton uranium.  The analyses were done using the
     FRAPCON-3 code, with using the Missah release model.  It was
     a best-estimate approach.  There were no operational
     transients addressed. 
               DR. POWERS:   Do I understand what the Missah
     release model is?  Do I know what the Missah release model
               DR. LAVIE:   The FRAPCON model, the FRAPCON code
     allows the user to choose, I think it's three different
     release models -- 
               DR. POWERS:   What are those from? 
               DR. LAVIE:   It has the traditional ANS 5.7
     approach -- excuse me, 5.4 approach, which our contractor
     believes is extremely over-conservative.  And based on his
     considerations, he decided to this of the three options he
     had available.  
               He also calculated the core inventories up to 75
     megawatt day metric-ton uranium, although they won't be
     useful to us because we don't have the gap fraction data
     that high.  The staff decided to use the PNNL data with some
     adjustments.  In our approach, the bottom line here was to
     balance the uncertainty in the gap fractions with other
     analysis conservatisms.  For example, in the fuel handling
     accident, we always considered the rod to be damages to be
     the peak burn-up rod, and it's also in the peak power
     position.  With fuel management the way it's performed, this
     is an impossibility.  The rod, the high burn-up rods would
     not be anywhere near peak-power position.  
               So what we ended up putting into the draft
     guidance -- and for comparison, I put the previous numbers
     from draft guide 1081 in there.  For the local, we decided
     to stick with the .005 for the gap fraction and use that all
     the way up to 62 gigawatt days metric-ton uranium.  This was
     consistent with some of the PNNL data that showed this would
     be appropriate.  If you'll recall, 1465 did have some
     language that if you had long-term cooling, you could use
     .03.  However, 1465 also said that the data was potentially
     suspect above 45 gigawatt day metric-ton uranium.  So
     combined with that information and what we had from PNNL, we
     decided to settle on .005 for the entire range zero to 62.  
               Now for the norm locus, fuel handling lock rotor
     accident, we decided to split it into two regions.  For that
     fuel which is lower than 40 gigawatt days metric-ton
     uranium, those would be the fractions we would suggest to
     use.  It would be acceptable to the staff.  And above 40,000
     but no higher than 62, we would use the fractions shown
               For the reactivity insertion accidents, as I
     mentioned before, we stayed with the old data until we have
     a basis for changing it.  Now -- 
               MR. KRESS:   Is the expectation that when they
     look at these other accidents, that they will make an
     assessment of what burn-up -- 
               DR. LAVIE:   I'll be getting to that -- 
               MR. KRESS:   -- is -- oh, you're gonna get to
               DR. LAVIE:   I'm gonna get to that.  One step -- 
               MR. KRESS:   Okay. 
               DR. LAVIE:   What we are putting in the guidance
     is for the default approach, acceptable to the staff, is
     that the gap fractions associated with the peak burn-up, rod
     burn-up, in the core would be used with the rod inventory
     adjusted for the maximum radial peaking factor.  So they've
     run the origin code, they've come up with a core inventory;
     they multiply for the maximum peaking factor for the entire
     core, out of the COLA.  So this'll change with each core
     upload.  And that'll give them the inventory in the entire
     rod.  They then will pick up the maximum burn-up in the
     core, okay, and use that for the gap fraction.  So the
     fraction times the inventory gives them the release.  
               Now that's -- for the fuel-handling accident, we
     are insisting on that approach because you really don't know
     which element you're gonna drop in the fuel-handling
     accident.  Recently, at one time reactors used to shuffle
     one-third of the core, and that way only a third of the core
     moved.   However, nowadays, for various reasons, we are
     seeing a lot more full core offloads.  So there's an equal
     probability that any element could be dropped.  So for the
     fuel-handling accident, we're retaining the conservatism
     that they must use the maximum COLA and the maximum burn-up. 
               Now, for the other accidents that get fuel damage
     in some designs -- a main steam line breaks, lock rotor
     accidents, steam tube ruptures -- if the licensee can
     demonstrate to us with reasonable certainty that he knows
     where the damaged fuel is in the core, then we will allow
     him to use the gap fraction appropriate for that element
     along with the radial peaking factor for that element. 
     However, for maintaining some degree of conservatism because
     of the uncertainty of the gap fractions, we are not letting
     them use a radial peaking factor less than one.  
               In some of these three-burn cores, the radial
     peaking factor can get down to .6 and .7 in that third
     region.  However, to maintain a degree of conservatism, we
     will not let them go less than one.  Now this is totally an
     optional method.  It will not apply to the fuel-handling
               I need to point out that very late in the process,
     after this document  was distributed for review is -- in the
     last week, as a matter of fact -- we have gotten the
     technical comment on this table.  And the NRR is working to
     resolve this technical comment.  We expect to be able to
     resolve it and retain what we have here.  If we find out
     that we cannot retain what we have here and we have
     significant changes, I will arrange to come back to the
     Committee and explain why we're changing it.  But this is
     what we expect to publish. 
               This is the iodine spiking species, which we've
     jumped ahead a little bit.  For the fuel-handling accident
     we had previously specified 99.75 percent elemental and .25
     percent organic -- recognizably conservative.  The industry
     suggests that we use the NUREG 1465 species.  Now the staff,
     when they first got this comment, gave some thought to this
     because we do have a very, very low pH in the spent fuel
     pool, typically 4 or 5.  And if you'll recall, 1465, with
     the iodine species specified there, if you maintain  the
     sump pH grade of the 7.
               We also had some concern about transport data. 
     The transport data we have for pool DF came out of that
     original Westinghouse work back in 1959.  Cold water -- now
     there's been an awful lot of work done on transport through
     pools, but it's typically not the, the stagnant pool such as
     a spent-fuel pool.  
               So for the final guide, we decided that we would
     adopt the fractions in 1465.  However, from a release
     standpoint, to the environment, we decided that the cesium
     iodide completely dissociates in the pool water and that
     because of the pH, it will re-evolve as elemental iodine. 
     Now, yes, this is a mechanistic process that would over
     time.  However, for the purposes of deterministic
     calculation, we have taken this assumption.  We are using a
     pool DF of 200, effective because it varies for the
     different isotopes, different species.  And with a pool DF
     of 200, the release from the pool ends up being 57 percent
     elemental and 43 percent organic. 
               MR. KRESS:   Now the 200 comes out of the DF for
     elemental iodine -- that's pretty high. 
               DR. LAVIE:   And organic. 
               MR. KRESS:   Unless it goes into solution.  
               DR. LAVIE:   Right. 
               MR. KRESS:   And then it has to dissipate.  And
     the organic is essentially not captured.
               DR. LAVIE:    Not captured at all.  The organic is
     what controls.  The organic is what controls -- this is why
     the organic jumps so high. 
               MR. KRESS:   So basically, everything that comes
     out -- well, it's about half and half when it gets there. 
               DR. LAVIE:   Right. 
               MR. KRESS:   But it's -- 
               DR. LAVIE:   We enter it here -- 
               MR. KRESS:   -- organic is so small that what
     you're doing is just reducing the elemental down -- 
               DR. LAVIE:   Right, and the organic becomes much
     more controlling. 
               MR. KRESS:   Yes. 
               DR. LAVIE:   So from an analysis standpoint to the
     environment, effectively we're back to what we had in the
     original.   Now we do point out in the guide, however, if
     the applicant, or licensee wants to come in with a
     justifiable mechanistic treatment for pool treatment that
     looks actually at actual iodine species and so forth, it
     will be considered on a case-by-case basis.  But the default
     deterministic method will, is what's hear.  
               MR. KRESS:   The problem I have with that is -- I
     like to do a concept of the cesium iodide and go into the
     pool water with elemental iodine.  It won't go in as the
     iodine, but you know, if it's gonna get released, it'd be
     released as the iodine. 
               DR. LAVIE:   Right. 
               MR. KRESS:   But the problem I have with this is
     the assumption that, that the gap has .15 percent organic.
               DR. LAVIE:   Right. 
               MR. KRESS:   There's no basis for that choice at
     all.  It might very well be .25, as is in the original DT
     1081.  I don't know what it is inside the gap, but there is
     no evidence for something like .15 percent organic in the
     gap at all.  And to put it in here and then say, now you've
     got 43 percent of what's released is organic is a little
     strange to me.  It's such a, such a small amount of stuff,
     all it does is govern things like the required closure time
               DR. LAVIE:   Filters. 
               MR. KRESS:   -- mostly.  It doesn't have real risk
     implications as much; it has some exposure and it affects
     things you do.  So I'm not really concerned.  But here you
     have a whole set of deterministic regulations.  They're
     basically based on this .15 percent organic, which has no
     basis at all.  You know, it just shows up.  And that's the
     kind of thing that bothers me. 
               DR. LAVIE:   Okay. 
               MR. KRESS:   You know, it's not a big deal, but it
     just bothers me to have regulations like that. 
               DR. LAVIE:   The um, the Westinghouse data that
     was used as the basis of the original did point out that
     there was organic due to manufacturing processes. 
               MR. KRESS:   Manufacturing -- 
               DR. LAVIE:   -- and, so that -- but they projected
     .25 percent. 
               MR. KRESS:   Yeah, and I think that's a better
     number to use because it's the only data we have. 
               DR. POWERS:   In this stage of the calculation,
     you're really hypothesizing, things go into the pool and
     then come back out. 
               MR. KRESS:   Yeah, and in that case -- 
               DR. LAVIE:   Okay, that's a good point, because I
     want to point out that the way these analyses are currently
     done, it's considered to be an instantaneous release from
     the pool.  Now if somebody wants to come back and
     mechanistically -- one of the things we have to stop
     worrying about if we start to say that some of this is gonna
     be captured in the pool and released over time is now we
     have to start looking, now the market changes the way this
     is modeled, to pick up the continuous release.  Right now,
     we do a puff release and it's gone.  
               This is a simplification, granted.  We think it's
     conservative.  We think it's conservative.  But if they want
     to come in with a mechanistic treatment, it will be
               DR. POWERS:   Well, what I was going to point out
     is that we do have the results of the Febus experiments. 
     They're a little different; they're looking at core
     degradation.  But they have the iodine coming into the
     containment model, closing to the sump, and then they get a
     repartitioning out -- their consensus is for round-number
     purposes, it's about 50/50 elemental-organic, maybe actually
     a little higher in organic than elemental at various stages. 
               MR. KRESS:   And that's because the iodine
     converts to organic in the pool, and they know that here.  
               DR. POWERS:   That's right.  And I'm wondering if
     -- the first line under final guide may well be wrong, but
     the third line ends up being right, perhaps for the wrong
               MR. KRESS:   It's probably right, but it will have
     the wrong quantities in it because of the DFs that are -- 
               DR. POWERS:   Right. 
               MR. KRESS:   It'll have much lower quantities, but
     once again, they got the conservatism that they're assuming
     it comes in instantaneously, when actually it takes a
     considerable amount of time for this stuff to come out. 
               DR. LAVIE:   So one of the things we recognize
     with this particular calculation, as you pointed out, the
     risk basis of this is maybe, as the risk-informed Part 50
     process continues, this may be an accident we'll stop
     worrying about.  So this particular accident is not worth an
     awful lot of modeling -- 
               MR. KRESS:   It's not, it's not worth a lot,
     that's right.
               MR. KRESS:   The other problem is that the DF
     factors are, are a little strange because they're based on,
     they're based on suppression pool data, where the gas that
     carries this stuff is a steam, it's a condensing gas. 
               DR. LAVIE:   Okay -- 
               MR. KRESS:   And what you have here is, you're
     gonna have cold, relatively cool nova gases that carry up
     these things, and I don't think you'll get the same DF. 
               DR. LAVIE:   Okay, the DFs we used here, Dr.
     Kress, we came out of the Westinghouse work back in 1959. 
     Westinghouse did a series of experiments, small-scale
     experiments where they entrained iodine in a carbon dioxide
     carrier -- 
               MR. KRESS:   Oh, it was a carbon dioxide -- okay. 
               DR. LAVIE:   Okay, and it was cooled, the water
     cooled and the pH was controlled in order to do that.  They
     then took that data, recorded it, graphed it, what have you. 
     They then went and got a 14x14 assembly, sheered it off,
     connected a gas volume below it, put it at the bottom of a
     23-foot pool.  But they didn't use the iodine; they used a
     carbon dioxide, they just used the carbon dioxide carrier. 
     Okay, and then they measured the rate and the rise of the
     bubbles and how much bubbles actually had rose to the
               MR. KRESS:   Okay, well that sounds like -- 
               DR. LAVIE:   And then they then correlated it -- 
               MR. KRESS:   -- pretty good chance of being
               DR. LAVIE:   The staff took the Westinghouse data
     and then massaged it a little bit further, because the staff
     at that time was concerned that the Westinghouse model
     didn't match some formulas the staff already had on mass
     transfer, even though Westinghouse had actually measured it. 
     Okay, the staff tried to backfit a formula into the data. 
     So the Westinghouse originally came up with DFs for
     elemental iodine as high as 800, and then the staff, because
     of its manipulations, pushed it down to 100.  We have
     brought it back somewhat.
               MR. KRESS:   Well, I tell you why I'm still in
     this discussion with this relatively minor thing, and that
     is that one of the purposes for redoing the source term
     itself was to get a little more realism into it.  Now we've
     introduced completely unrealistic -- 
               DR. POWERS:   All this conservatism here. 
               MR. KRESS:   Yeah, parts -- completely
     unrealistic, no basis parts for part of the thing that has
     little relevance or little impact in terms of things, but
     it's still, it's still going away from the intent of the new
     source term to put a little realism into it.  So that's,
     that's all that's bothering me.  It's not that I'm concerned
     about this point here or any kind of safety impact it'd
               DR. LAVIE:   We did recognize in conservatism is
     this is a decrease by a factor of two.  Plants typically
     come in -- the limit for this particular accident is 75 rem
     thyroid, and they typically come in anywhere from 25 to 30. 
     I don't think of any plant that's had a fuel-handling
     accident be eliminated.  This accident's primarily done to
     ensure that the filters and systems involved with the spent
     fuel handling areas are adequate. 
               MR. KRESS:   I guess the question is will this
     serve any purpose?  I guess it will.  I'll have to think
     about it. 
               DR. LAVIE:   We'll consider your suggestion about
     sticking with the 100 percent cesium iodide -- 
               MR. KRESS:   You're gonna get basically the same -
               DR. LAVIE:   Right.
               MR. KRESS:   -- when you do that.  
               DR. POWERS:   I guess I wonder -- you know, if I'm
     sitting around, trying to figure out how I'm going to
     respond to an accident, and you tell me, okay, you've got a
     puff release and everything's over.  And I pick up one set
     of actions.  If instead you're telling me I've got a
     protracted release -- 
               MR. KRESS:   Over a long period of time. 
               DR. POWERS:   -- over days and days and days, I
     think I'd come up with a different set of actions. 
               MR. KRESS:   Yeah, and that's the other thing that
     bothers me.  Part of the source term specification is the
     time.  And here we've gone back to the puff release, just
     for convenience, when we know it's not a puff release, but
     we're saying it's conservative and I'm not sure it is,
     because you, you have one set of actions versus another and
     I'm not sure which is the right things. 
               DR. LAVIE:   I can try to address that.  Is that -
     - when we model this accident, was assume partially at the
     release of the gap activity that has collectively up to the
     point where the fuel was removed from the core, so what
     we're releasing is in essence the gas that's in the rod;
     it's gonna come out.  The rod is at 800, 1600 pounds of
     pressure, depending on its burn-up, and even at the 23-feet
     pool depth, you're only looking at about 30 pounds of
     pressure, so the gas release from the fuel element will be
     very, very rapid.  
               If the filter systems in the fuel handling
     building are capable of handling a puff release, they're
     capable of handling a protracted release. 
               MR. KRESS:   Well, your puff release is gonna be,
     the amount of iodine that's in it, it's gonna be about one
     percent of the total that's release from the gap. The rest
     of it ends up in the pool, and what we're concerned about is
     that other 99 percent is not dealt with here at all, because
     it's gonna start coming out also. 
               DR. LAVIE:   That's correct. 
               MR. KRESS:   And it should be dealt with in terms
     of fuel handling accidents somewhat, and it may come out for
     a long period of time and it may be a lot more than the --
     this thing may be designed only to handle at one percent,
     and here you've got 99 percent more of it coming out.  But I
     think that's the concern. 
               DR. LAVIE:   That's the basis of our second
     bullet.  We're assuming that it completely dissociates -- 
               MR. KRESS:   Yeah, we're saying it will re-evolve. 
               DR. LAVIE:   Instantaneously.  Of course it won't,
     but we're modeling as it does, so we are capturing that
               MR. KRESS:   You're already adding that in as a
     puff release. 
               DR. LAVIE:   Right. 
               MR. KRESS:   Okay, so we're saying if it's
     designed to handle that as a puff release -- 
               DR. LAVIE:   Right. 
               MR. KRESS:   But it may not. 
               DR. LAVIE:   But if they want to come back and
     look at it more deterministically, more mechanistically,
     then we certainly will consider it. 
               MR. KRESS:   Yeah, it comes out in more protracted
     time versus a puff release -- with a puff release, you've
     got competition between where that iodine goes.  Does it all
     go into the -- if you're assumption is it all has to go
     through whatever the clean-up system is, then you may be
     right.  But if the assumption is that that cesium iodide
     leaks out the containment, goes through some other sort of
     chemical reaction with the sprays or whatever, gets removed
     -- but you may be right.  I guess I missed that statement
     through.  You are using all of the cesium -- 
               DR. LAVIE:   Right.  Right, yeah.  Most licensees
     when they do this particular calculation, do this with a
     spreadsheet.  You know, a times b times c.  It's really --
     most of them do not do it on a time-dependent basis.  It's
     the total quantity released.  They get a total curies
     released; they convert that right to rem.  Very few people
     actually model this in any degree of -- 
               MR. KRESS:   I think I may have been tempted to go
     back and say, you know, the DG 1081 says you get 99 percent
     elemental, .75 and .25 organic, and it all goes into the
     containment instantaneously and deal with it, because you
     end up at the same place. 
               DR. LAVIE:   Exactly the same place, but for a
     licensee who wants to do it mechanistically -- 
               MR. KRESS:   You can still say, all right, if you
     don't agree with this tell me, justify some other.  So I
     think I'd, rather than have these arbitrary things in there
     that really, really raise questions -- particular the first
     line raising this question -- I would have just gone back to
     the DG 1081 and said it all goes into the containment
               DR. LAVIE:   Okay. 
               MR. KRESS:   Or, as an alternative, I would have I
     would have said, .25 percent of it goes in immediately and
     only a DF of 500 of the element goes in immediately, and the
     rest of it comes out protracted over time.  And I would have
     made a calculation for what that protracted time release is. 
     But that's not an easy calculation to make. 
               DR. LAVIE:   No.  It may be very plant-specific.   
               MR. KRESS:   It may be plant-specific, but you
     could, you could deal with the plant-specific issues in a
     general way. 
               DR. LAVIE:   Actually we're hoping this one goes
     away when we risk-inform Part 50.  We may be down to just a
               On the second limitation, just to refresh you, as
     you recall from our original discussions last fall, is we
     have two different ways a licensee can get into the
     alternate source term is a full limitation, in which they
     come in and do it as a minimum of the full-fledged, full-
     blown loca analysis, and then we would grant them a broad
     scope approval that this is now in your design basis; you
     can then use the alternate source in TEDE for all future
     radiological analyses.  
               Realizing that not all licensees may want to go
     that route, and with deference to the Commission direction,
     we also provide a means to do it selectively, that they
     could pick small little applications and apply that small
     application.  When we wrote the draft guidance, it was our
     intent that, those selective limitation licensees, if they
     want to use the alternate source term for some other
     application that they had to come back and talk to us.  This
     was one of the benefits of going to the full.
               We got several comments on that, and when we
     started looking back at it, we had realized that we had
     probably gone a step too far.  And what we finally decided
     to do and change the guidance to is, recognizing that when
     we gave them the approval for the selective implementation,
     we approved some characteristic of the alternative source
     term and the use of TEDE if they did something that required
     a dose calculation.   And we put that in the design basis. 
     Now once that's in the design basis, that's part of their
     design basis, and we really don't need to worry about that
     again.  So if the licensee wants to make a subsequent
     modification using those characteristics that we have
     already approved, they can go ahead and do it assuming they
     can pass the 50.59 criteria.  
               However, the staff review will be required under
     50.67, the regulation for the alternate source term, if they
     decide to use an alternate source term criteria
     characteristic, or the dose criteria, which is not already
     in their design basis.  So a licensee who may come in and do
     a timing-only application could not subsequently go off
     without coming back to us and do a calculation that involved
     the other characteristics.  Or, if the licensee decided he
     had new data on gap fractions and wanted to change his gap
     fraction, he could not do that without staff approval
     because that's what's currently required under 50.67.  
               The revised position here is consistent with the
     50.59 guidance and 50.67.  So it would give them a little
     bit more flexibility than what we had previously. 
               MR. KRESS:   I particularly thought this was a
     very insightful part of your change.  And it addressed the
     earlier question, one of the earlier questions we had -- 
               DR. LAVIE:   Right. 
               MR. KRESS:   -- and I thought this was very good
     way of handling it. 
               DR. LAVIE:   I believe this was always our intent,
     but when we wrote the language it didn't come across that
               MR. KRESS:   It just never came true that way,
               DR. LAVIE:   One of the things that came up -- out
     of all the 134 comments we received, and some of them were
     very, very good comments, this one was one of the ones that
     really blew us away because it was one of the last sets of
     comments that came in, and I think this was one of the best
     ones we got.  The individual pointed out, under the
     alternative source term and the way that we wrote the draft
     guidance is that it's possible for a licensee to have
     analyses on his books that are not based on TEDE and are not
     based on the alternative source term.  If he could show that
     they were bounding, he could let them stand.  But our
     guidance said that in the future, if you have any  reason to
     resolve those calculations for any reason, use the, what's
     now in your design basis, the alternate source term and
               This gave a problem with a guide to 50.59 because
     as you call the new 50.59 guide in determining what's a
     minimal increase in consequences has you comparing prior to
     after. Okay, so we had all these calculations out there on
     whole-body and thyroid, and the new doses were going to be
     in TEDE.
               Working with Alan McKenna and the other folks on
     50.59, we decided the approach to do is that for this
     particular regulatory guide, we would put in an equation and
     some guidance on how to convert that prior value, and it's
     nothing magic to this.  This is the waiting factor for the
     thyroid, which goes into constituting TEDE.  So what the
     guide will say is that if you have one of these situations,
     before making the 50.59 comparison, convert your result.  It
     was a very good catch. 
               MR. KRESS:   It was a very good guidance. 
               DR. LAVIE:   We didn't want to go into too much
     detail in here because we prefer that people go to the 50.59
     reg. guide and the industry document that it endorses,
     rather than going into all sorts of detail, what constitutes
     minimum and all that stuff.  So all we did here is that,
     when you get ready to do the comparison, this is how to get
     the prior result.
               There was a lot of other technical changes, not as
     major as the ones we've just gone over.  With the guide to
     EQ, as you recall, we have a generic safety issue in
     progress resolving the cesium in the sump water.  This has
     not yet been resolved, so because we're going final in the
     guide, we have added text to the guide that talks about the
     GSI and also specifies that until the GSI's resolved, the
     licensees are allowed to use TID 1484 or the AST. 
               MR. KRESS:   When that GSI gets revolved, will you
     go back and redo the guide and the review plan, or just -- 
               DR. LAVIE:   We expect that we'll be revising this
     guide in probably the next two-year time frame because of
     what's going on in risk-informing Part 50, and at that time. 
               DR. SEIBER:   I see.  But you'll have the
     opportunity to pick it up. 
               DR. LAVIE:   Of course, as guidance, the licensee
     could point out to us in their submittal that the GSI had
     now required them to do something different or said that
     they could use the TID 1484 all the time.  This is only for
     re-analysis required under the guide.  
               It was pointed out that the appendix I we had put
     in, though it discussed all the good guidance on the EQ
     doses inside containment, we really silent with regard to
     doses outside containment, so there was some general
     guidance added there, on that topic.  
               The steam generator iodine transport -- we
     corrected an error regarding the decontamination credit when
     the tubes are uncovered.  Although we had described very
     clearly the model for flashing and non-flashing and
     scrubbing, we negated all of it in the final paragraph that
     says, if your tubes are uncovered, you get no partitioning
     credit.  That was technically wrong.  That's been corrected. 
     They now go back to the flashing fraction.  If it's, if it
     is not flashed and stayed in the bulk water, then the
     partitioning would apply regardless of where the water was. 
     However, for the fraction that did flash, then they would
     have to adjust the scrubbing fraction.  So we corrected that
               One the spray DF, although we would expect a lot
     of the licensees to use the rad trap models, which don't
     have a spray DF limitation per se, recognize that some
     people will stick to the models in the standard review plan,
     for which there is a spray DF maximum.  We had put in some
     guidance there as to when you take the total volume, because
     recognizing the new source term enters the activity over
     time instead of all the time equals zero.  However, we made
     a mistake when we put that in, and we have since revised
     that to correct the guidance.
               We were asked to consider allowing building mixing
     credit for the fuel handling accident.  This is something we
     have typically not done, but we decided that if a licensee
     can justify it, it ought to be allowed. 
               MR. KRESS:   I'm not quite sure I understand that. 
               DR. LAVIE:   Okay.  In the fuel handling accident,
     traditionally we have assumed that that puff of gas that
     leaves the fuel goes straight into the ventilation plenum,
     no mixing in the building.  And in most cases, that's the
     way it's going to happen.  Now there are some designs,
     however, where there may be a potential for mixing, and if
     they can justify it, it'll be allowed.  
               MR. KRESS: So you have a mix-in and it goes into
     the ventilation, but it does it -- 
               DR. LAVIE:   But a, much delayed period of time. 
               DR. SEIBER: But in the aggregate, it's the same as
     a puff release. 
               DR. LAVIE:   Exactly.  Yeah, what comes out of the
     water is still a puff, but it mixes in the building and can
     be released over the next two hours. 
               DR. SEIBER:   But it's still considered puff. 
               DR. LAVIE:   Right.  They get some dilution.  The
     concentration's a little lower.  
               We have also decided -- there was a requirement
     that was added on the loss-of-coolant accident for the ECCS
     system leakage outside the containment.  There was a
     requirement added several years ago, which was largely
     intended to force the installation of filters, that if you
     did not have an engineered safeguard filter system in those
     areas, then you analyze a 50-gallon-per-minute leak.  That
     requirement has been deleted. 
               Dr. Kress pointed out, the ACRS gave us a letter
     last October.  There were three recommendations.  Two of the
     recommendations we had, part of our response to table action
     until we got to the guide, we we're going to discuss what we
     did to resolve them, now there we're in the guide stage.  
               The ACRS had recommended the removal, the
     requirement to have prior NRC approval for changes resulting
     in reduction of safety margins should be re-evaluated in
     light of analytical assessments performed by research and
     the results of the pilots.  And the discussion also
     identified using 50.59 as an alternative.  The Staff
     committed in the response to look at this requirement during
     the public comment period.  As a result of our review, we've
     decided to retain the language in the guide, for two
               One is, this particular guide has to apply to the
     initial implementation of the alternate source term for
     which 50.59 would not be applicable.  The re-baselining in
     the pilots provided a lot of good insights, but it was based
     on a limited sample of plants, and we don't feel that that
     limited sample provides an a priori basis to summarily
     disposition all potential plant-specific and modification-
     specific impacts.  So we retained the requirement that the
     licensee will need to consider that.  
               We did, however, add language referencing 50.59
     for the subsequent modifications. 
               MR. KRESS:   But I think that's basically what we
     had in mind anyway with this, was the subsequent
     modification.  So I think this is a pretty good response. 
               DR. LAVIE:   The other recommendation that was
     carried over to the guide was the recommendation we should
     modify the proposed redefinition of the source term to
     eliminate the connotation that the release is necessary to
     the containment, but should retain the wording "released
     from the RCS."  At the time we responded, we pointed out
     that we weren't going to change the rule language, but that
     we were committed to reviewing the reg. guide to ensure that
     the description was appropriate, that it would not cause
     this confusion.  The reason we did this is that the 50.2
     definition had to address accidents other than the loca,
     since the reg. guide and the alternate source term does. 
     And those accidents may not involve the RCS or containment. 
     So we decided that we'd best leave the definition in the
     50.2 alone and make sure that it was clear in the guide.
               The accident-specific appendices in the draft
     guide and the final guide provide the guidance in what
     constitutes the source term.  We don't expect a licensee to
     go back to 1465 and interpret it.  The guidance is in this
     reg. guide. 
                         MR. KRESS:   As long as it's clear.
               DR. LAVIE:    believe it is, Dr. Kress.  The final
     guide is a stand-alone document.  We don't expect licensees
     to refer back to 1465.  However, we did add clarifications
     to the final guide to ensure that the release from the loca
     is consistent with the definition of 1465. 
               MR. KRESS:   I think that fixes that problem. 
               DR. LAVIE:   Okay.  Those were the major changes
     made.  As I pointed out earlier on the gap fractions, we
     expected to resolve those and be able to use the numbers we
     currently have there.  If we don't, I will get back to the
     Committee and will decide the approach we want to take at
     that time.  Am I able to answer any more questions you might
               MR. KRESS:   I thought the reg. guide were pretty
     well-conceived documents that dealt with this issue very
     nicely.  I had a lot of minor problems with it, some of
     which I've already -- 
               DR. LAVIE:  Okay. 
               MR. KRESS:   -- with things like speciation and
     gap release.  I had a bunch of other little things that I'd
     like to bring to your attention, and I don't think it's
     worthy of putting it in a letter, and I don't even know if
     it's worth wasting our time on here.  A lot of them are
     editorial comments.  Some of them are things like -- 
               DR. POWERS:   There are a few things that they've,
     you might help to go through that. 
               MR. KRESS:   Well, okay.  Some of them -- 
               DR. POWERS:   I mean, for editorial purposes, the
     draft guide does have quite a few -- 
               MR. KRESS:   Yeah, and I could give those to him
     separately.  But there are things like, they've retained
     this business of requiring the power to be 1.02, the rating
     power, which in view of all the other uncertainties, that
     seems a little strange. 
               They justify the breathing rates when they
     calculate the doses, to three significant figures, which
     seems a little strange also. 
               MR. ESTRADA:   Good catch. 
               MR. KRESS:   They still are talking about some
     magic thing called an initiation temperature for, ignition,
     ignition temperature.  And there's gap release speciation;
     it's not clear always in the reg. guide as to when the clock
     starts on these timing things.  So there's a lot of little
     bitty, a few little bitty things in there that I don't think
     make a hill of beans in difference in the outcome, but these
     are mostly editorially things that I can probably write down
     as a list and give them to him and send -- but I don't think
     they're worthy of putting in a letter. 
               DR. POWERS:   Have you received things like that? 
               DR. LAVIE:   Yes, certainly.  
               MR. KRESS:   I haven't done it yet, but I -- 
               DR. LAVIE:   Whatever we can do to improve the
     document is certainly appreciated.  
               MR. KRESS:   You can look at them and dispose of
     them as you see fit.  I don't see that it makes much
               The other thing, I guess, is -- if there are no
     more questions from other members, I think we, we have an
     NEI reg here, and you don't care to comment?  Okay, so with
     that -- 
               DR. POWERS:   Sounds like the industry's happy. 
               MR. KRESS:   Well, I think the industry's pretty
     well pleased with the outcome of this.  It looks like a
     pretty good set of guidance to me. 
               DR. POWERS:   The important thing is that we're
     injecting some of the products of the substantial research
     effort into the regulations.  
               MR. KRESS:   And getting a little more realism
     into it. 
               DR. POWERS:   I guess I need to cogitate more
     about this checkered approach toward defining some of the
     criteria here.  I hesitate only because if the accident
     disappears from consideration, how much effort do I want to
     invest in an accident that's never limiting anyway? 
               MR. KRESS:   That's always a good question. 
               DR. POWERS:   Members have any other comments
     they'd like to make on this? 
               DR. BARTON:   Nah, it's a pretty good piece of
               DR. POWERS:   Okay, well thank you. 
               DR. LAVIE:   Thank you. 
               DR. POWERS:   And we will -- I can't start until
     the Federal Register says I can start, recess until 2:30.
               DR. POWERS:  Let's go back into session.  We have
     got to welcome Professor Apostolakis here.  I hope the
     graduation celebrations went well.
               DR. APOSTOLAKIS:  They went very well.
               DR. POWERS:  Members have before them a Document
     14, Reconciliation of ACRS Comments and Recommendations. 
     They should examine these and if they have any comments.
               I am tempted to say that we are now going to
     explore an issue that involves an oxymoron, but I am going
     to avoid that, and turn to the issue of quality in PRA.  And
     Professor Apostolakis, I think you are our leader in this
               DR. APOSTOLAKIS:  Yes.  Thank you, Mr. Chairman. 
     The Commission directed the staff to develop some
     recommendations regarding the judgment of how good a PRA is
     in the absence of the ASME and ANS standards, which, as we
     all know, are being developed right now.  This is a very
     recent SRM, April 18, 2000.  And your response is expected
     by the end of this month, I understand.  June 30th, is that
               MR. MARKLEY:  Yes.
               DR. APOSTOLAKIS:  We have not received the
     document from the staff, understandably so, but since the
     Commission expects it by the end of the month, I suppose we
     will also see it then.  And we will have to discuss at the
     end of this whether we want to write a letter.  If we do,
     that will be in July.
               The ASME standard, though, has been promised to us
     sometime in June.  Right, Mike?
               MR. MARKLEY:  Yes, June 14th.
               DR. APOSTOLAKIS:  June 14th.  And we have, in
     fact, scheduled a subcommittee meeting June 28th to discuss
     that.  So I don't know now whether the work you are doing
     now will really ever be used, unless the ASME standard turns
     out not to be acceptable, in which case, of course, what you
     are doing now will be very, very valuable.  But these are
     perhaps questions whose answers are coming.
               MR. MARKLEY:  Yes, that's correct.
               DR. APOSTOLAKIS:  Okay.  So without further ado, I
     guess Mr. Cunningham has the floor.
               DR. POWERS:  Let me, before we get into this, the
     Commission asked you to address the issue of PRA quality. 
     Unpleasant experiences that have occurred throughout my
     professional career have taught me that the definition of
     quality is a variable thing.  And can you tell me what the
     Commission had in mind when they used this word "quality"?
               MR. CUNNINGHAM:  We will try, try to lay the
     context, anyway, of the question.
               DR. APOSTOLAKIS:  Okay.  Go ahead.
               MR. CUNNINGHAM:  Thank you.  My name is Mark
     Cunningham, I am with the PRA branch in the Office of
     Research.  We have got four of us up here today.  To my
     right is Mary Drouin, also with the Office of Research;
     Gareth Parry, from the Office of Nuclear Reactor Regulation;
     and Richard Barrett, the chief of the PRA branch in the
     Office of Nuclear Reactor Regulation.
               I am going to start this out, but all of us are
     going to hop in at various points and talk about what we
     have got.
               DR. APOSTOLAKIS:  So there is much to be said
     about PRA quality then?
               MR. CUNNINGHAM:  Pardon?
               DR. APOSTOLAKIS:  Since all four of you will be
               DR. POWERS:  It takes that many people to search
     for PRA quality.
               DR. APOSTOLAKIS:  In the absence of tools.
               DR. POWERS:  Because they are being out-gunned.
               MR. CUNNINGHAM:  Okay.  Well, let's see, there is
     four parts to our presentation today.  I am going to provide
     some background of what is going on right now in terms of
     the SRM and other activities and give you a first, kind of a
     general idea of how we intend to respond to the SRM, at
     least today.  Part of that response is going to be what we
     call an attachment to the SRM.  We are writing a document
     that Mary and Rich and Gareth will talk to you about that
     contains some -- the substance of the presentation, and then
     I will come back at the end and talk a little bit about what
     we have to do over the next month or so.
               DR. APOSTOLAKIS:  Over the next month?
               MR. CUNNINGHAM:  In responding to the SRM.
               DR. APOSTOLAKIS:  But the paper is due the 30th.
               MR. CUNNINGHAM:  Yes.  Well, this month.  What we
     will be doing this month.
               DR. APOSTOLAKIS:  Okay.
               DR. POWERS:  This month is young yet, George.
               DR. KRESS:  Next month in the staff means the one
     coming up, not the one -- 
               MR. CUNNINGHAM:  Over the next 30 days is what I
               DR. APOSTOLAKIS:  The next 30 days takes you into
               DR. POWERS:  Yes, but all these people are working
     16 hours a day, so they actually get two months for every
     calendar month.
               DR. APOSTOLAKIS:  Maybe we can start to talk about
     serious matters.
               MR. CUNNINGHAM:  Anyway, right now the staff has
     got four issues related to the general issue of PRA quality
     facing it, that it will be facing over the next few months. 
     The first is the response to the SRM that Professor
     Apostolakis talked about.  This came about in a briefing
     that the staff had on the risk-informed regulation
     implementation plan.  And in that briefing, the staff talked
     about some of its concerns, that the schedule for the ASME
     standard was slipping, or appeared to be slipping.
               The Commission made comments, various
     Commissioners at that time made comments about the general
     question of, how are we going to deal with the fact that the
     standard is slipping in time, and what are we doing to make
     sure that the PRAs that we are reviewing and we are using
     are good enough for the task?  So, in a sense, that is what
     I think the intention was in terms of the quality.  Are
     these -- are the PRAs that we have available to us, or the
     licensees are using, good enough?  And how are we confident
     that they are good enough to be used in the applications
     that we have got in front of us today?  
               So, I think that was, as I recall, kind of the
     general context of the quality question, and it got kind of
     condensed down to a definition of PRA quality.
               So, anyway, right now we have this, we owe at the
     end of the month a response to that SRM.  In parallel, we
     have got a couple of other things going on.  The Nuclear
     Energy Institute has submitted a certification document, one
     of many documents that it is submitting in the context of
     possible use in the Option 2 analysis of Part 50.
               DR. APOSTOLAKIS:  I am not sure that we have
     really investigated or discussed the certification process. 
     We had a small presentation, as I recall vaguely, but I
     think -- 
               DR. SEALE:  We had a presentation from the GE
     Owners Group, as I recall.
               DR. APOSTOLAKIS:  Right.  But it was -- 
               DR. SEALE:  On their certification process.
               DR. APOSTOLAKIS:  It didn't go into detail,
     though.  It was more a high level description.  In fact,
     what I am saying is I am wondering whether the members would
     benefit by reading this document if you can give it to us.
               MR. CUNNINGHAM:  Yes, certainly in the context of
     how the staff is proceeding and things, and how -- 
               DR. APOSTOLAKIS:  Yeah, because we really have to
               MR. CUNNINGHAM:  It is an important background
     document to the Option 2 work that you will be reviewing.
               DR. APOSTOLAKIS:  We have to understand the
     certification process.  And I mean just to have high level
     discussions, as you know, we look at this and that, it
     doesn't mean anything to me.  I really have to see the
               MR. BARRETT:  The schedule for the staff review of
     that document hasn't been firmed up yet, but it is going to
     be -- I believe it is going to be a schedule sometime toward
     the end of this year.  So, in your thinking about what you
     want to review and when you want to review it, you might
     keep in mind that we will certainly be coming to talk to you
     about the staff review.
               DR. APOSTOLAKIS:  I would like to have the
     document itself, you know, to start educating myself, you
     know, in anticipation of your visit here, Rich.
               DR. SHACK:  Is that the NEI document that will
     also be used to classify components under the Option 2? 
     That is a different document?
               MR. BARRETT:  Those are separate documents, but we
     are going to be reviewing them in tandem.
               MR. MARKLEY:  But there is also four separate
     certification processes, right, for each one of the Owners
     Groups, that they are not altogether that linked?  I mean
     there are similarities, but they are different.  Is that
               MR. CUNNINGHAM:  That is correct.  
               MR. BARRETT:  There is one NEI submittal, NEI
     0002, but there are the sub-tier criteria that are used by
     the various groups are different, because of the differences
     in the reactors.  Maybe Mike Cheok could -- 
               MR. MARKLEY:  That's fine.
               MR. BARRETT:  Okay.
               DR. APOSTOLAKIS:  So we will get a copy of this?
               MS. DROUIN:  Yes.
               MR. CUNNINGHAM:  Yes.  As Rich was kind of
     alluding to, over the next few months or so, we will be --
     the staff will be reviewing the information NEI submitted in
     the context of its possible use in the Option 2 work.
               DR. APOSTOLAKIS:  But what if the ASME standard is
     approved, is accepted by the staff, then what happens to the
     NEI document?
               MR. CUNNINGHAM:  I will come back to that.
               DR. APOSTOLAKIS:  Okay.
               MR. CUNNINGHAM:  The next slide, slide 4 is the
     other things that are happening kind of in parallel in time
     with the NEI information and the Commission SRM is that we
     expect to see the next version of the ASME standard for
     staff review, if you will, about the end of this month.  So
     this is Rev. 12 of the ASME, proposed ASME standard.
               DR. APOSTOLAKIS:  Out of how many, do you think?
               MR. CUNNINGHAM:  Out of 12.
               DR. APOSTOLAKIS:  Okay.
               MR. CUNNINGHAM:  The goal of ASME is to have it
     out the latter part of this month.  There is a public
     workshop on it June 27th, that sort of thing, to tell
     people.  And they are asking, they are soliciting comment
     over a 60 day period for that.  So, in the July-August
     timeframe, the staff expects to be looking at the ASME
               In about the same timeframe, ANS expects to issue
     its draft standard on external hazards.
               DR. APOSTOLAKIS:  It says only seismic.
               MR. CUNNINGHAM:  It says seismic on the slide and
     I have to apologize.  The slide -- the standard covers -- is
     mostly seismic, but it covers also things such as external
     flood and high winds and that sort of thing, how to analyze
               DR. APOSTOLAKIS:  Fires?
               MR. CUNNINGHAM:  Not internal fires.
               DR. APOSTOLAKIS:  Oh.  Who is covering that?
               MR. CUNNINGHAM:  The National Fire Protection.
               DR. APOSTOLAKIS:  805?
               MR. CUNNINGHAM:  Yes, the 805 at this point is the
     standard that is under review.  So, ANS will be issuing its
     -- or has a goal of issuing its external hazards standard
     for public comment, again, around the end of this month or
     in early July, again, for a 60 day period or review.  Just
     for what it is worth, that covers, in the seismic area, that
     covers both the seismic PRA and the seismic margins
               So, again, the staff is expecting that in the
     July-August timeframe, we will be looking at those documents
     and commenting on them.  
               The goal of ASME right now is to have the final
     version of their standard out in January of next year.  The
     goal for the seismic or the external hazards work by ANS is
     to have it done in September.  I should also note there, ANS
     is also working on a standard for low power and shutdown
     analysis.  That right now is scheduled to be out in
     September and finalized in December, but we just have a
     feeling that that is not going to happen that quickly.  That
     one is a little further behind that the seismic work.
               So, at any rate, we have got three or four things
     in front of us.
               DR. APOSTOLAKIS:  The ANS low power shutdown work
     is the standard on how to do a risk -- a PRA for those
     modes.  It is not how to manage risk during those modes.
               MR. CUNNINGHAM:  Correct.  Correct.  And it has a
     quantitative approach to assessing the risk and a more
     qualitative approach to assessing the risk.  It is intended
     to be part of standard.  But you are right, it is not how to
     manage an outage, if you will.
               So, again, the staff has three or four things in
     front of us, all of which are related to the issue of PRA
     quality.  So what we intended to do is -- 
               DR. APOSTOLAKIS:  Actually, you know, that is
     confusing.  You can qualitatively manage risk, but you
     cannot qualitatively assess risk.  The only way to assess it
     is quantitatively.  
               MS. DROUIN:  What was proposed by the project team
     from the qualitative approach was to create a benchmark, and
     then you would compare your plant against that benchmark to
     see where you fell.  And to try and establish a benchmark to
     the level where it didn't contribute on a relative basis to
     the full power, and as long as you met that benchmark or you
     were below it, then you were okay.  I mean that is just kind
     of a quick summary of what the qualitative approach.
               DR. APOSTOLAKIS:  Which is really managing.  Which
     is really managing rather than assessing.
               MS. DROUIN:  In a sense, yes.
               DR. KRESS:  When you said benchmark, you mean a
     benchmark PRA?
               MS. DROUIN:  A benchmark simplified, I should say
     simplified PRA.
               DR. KRESS:  Well, that is not managing risk at
     all, it is just a qualitative way to compare your PRA with
     something that has a known -- 
               MS. DROUIN:  Risk associated with it.
               DR. KRESS:  A known uncertainty.
               MS. DROUIN:  But it does have a management part,
     because you would manage, --
               DR. APOSTOLAKIS:  Yeah, because the management, it
     is really management. 
               MS. DROUIN:  -- you know, your configuration to
     meet or stay below that benchmark.
               DR. APOSTOLAKIS:  What you do.  Again, it is not
     really a simplified PRA.  A limited scope PRA.  You simply
     something -- 
               MS. DROUIN:  That is probably a better
     characterization, yes.
               MR. CUNNINGHAM:  Slide 5 then provides basically
     an outline of what we intend to -- of what the structure
     will look like of the response to the SRM, and that is going
     to lay out what we intend to do over the next few months to
     deal with this, how to deal in kind of a more integral way,
     each of these individual issues I have talked about before.
               What that means is the SRM is going to first
     summarize what the Staff is now doing and what that means is
     again in the context of the Commission briefing is in the
     context of the applications that the Staff is now using, in
     the places the Staff is now using PRA what is the Staff
     doing to ensure the appropriate quality and scope of the PRA
     for that application.
               One example of that really is in the license
     amendment context.  Today we use Reg Guide 1.174 and SRP
     Chapter 19 to guide us through how we ensure that the PRA is
     adequate for the intended use.  It is general guidance at
     this point but it served us well I think in terms of license
     amendments.  That we are going to try to summarize to the
     Commission how that is being done today, and Rich will come
     back a little bit later to talk about how we are going to
     elaborate on what is in the existing Reg Guide and SRP.
               We are going to then propose or recommend to the
     Commission that the Staff or inform the Commission that the
     Staff has some other things we are going to do to integrate
     all these pieces together.
               One is we are in the process of writing a couple
     of things that will help better lay out how we use PRA in
     the Staff reviews and then what is needed in that PRA, in
     those PRAs for those applications.
               The idea is to draft a document and attach it to
     the Commission paper and summarize it in the paper itself.
               DR. APOSTOLAKIS:  I must say, Mark, I am a little
     bit confused.  Given the time scale on which the Agency
     operates, if the ASME standard is any good you don't need to
     do this because by the time you are done with this, the
     standard will be out, so do you guys know something we don't
               MR. CUNNINGHAM:  No, not well.
               DR. APOSTOLAKIS:  Are you preparing yourselves now
     independently to judge the last bullet there --
               MR. CUNNINGHAM:  Yes.
               DR. APOSTOLAKIS:  -- to be able to review the
     standard and --
               MR. CUNNINGHAM:  Yes, that is what we are doing.  
               DR. APOSTOLAKIS:  So you are positioning
               MR. CUNNINGHAM:  We are positioning ourselves.  We
     are doing our homework or whatever to say -- and these 
     Staff documents were intended to lay out what are we going
     to use as the basis to review the ASME standard when it
     comes in next month and what are we going to use as the
     basis for reviewing the certification document.
               We think it needs to be one document that spells
     out how we are going to do that for each of those things.
               To get back at a point that I believe you asked
     about earlier, I think we go back to Reg Guide 1.174.  We
     talked about either a consensus standard or certification
     process could be found to be acceptable in ensuring needed
     PRA quality.
               DR. APOSTOLAKIS:  For some applications.
               MR. CUNNINGHAM:  For some applications, and I
     think that is the context we are still working in. We are
     not presuming that one or the other would obviate the need
     for the other, that we can see that either of these
     documents, the ASME standard, ANS standard or the
     certification process could be acceptable so we are
     expecting it.  We are not prejudging at this point that
     either will replace -- one that will replace the other.
               DR. APOSTOLAKIS:  So you are not really sending a
     message to the ASME that the standard may not be acceptable?
               MR. CUNNINGHAM:  No, I don't think we are
     intending to send that message at all but we need to do our
     homework and set out what is it that we want to establish is
     what we want, if you will, and Mary and Gareth and Rich will
     talk about this in a little while.
               DR. APOSTOLAKIS:  Is Mary the only one who
     participates in the ASME activities --
               MS. DROUIN:  Yes.
               DR. APOSTOLAKIS:  -- from the Staff, I mean from
     you four?
               MR. CUNNINGHAM:  Mary is the representative of the
     NRC on a committee.  All of us are involved in reviewing the
               DR. APOSTOLAKIS:  Oh, okay.
               MR. CUNNINGHAM:  But Mary is the official point of
     contact, if you will.
               At any rate, we will talk about a little bit later
     these documents.  We think it may be appropriate to update
     Reg Guide 1.174 and/or the Chapter 19 to reflect what we
     write in these documents and just somewhat coincidentally we
     are going through the process to come up with the next
     update of the Reg Guide and the SRP, so the timing may be
     right for that.
               We intend to review the submittals, either the
     certification documents and the ASME standard draft, against
     what we are writing down, basically, provide comments back
     to the appropriate people, either ASME or ANS or NEI, and
     then when we get down the road and get the final versions of
     those documents we would be prepared to review them, again
     against what we have written down and endorse them or
     endorse them with exceptions.
               At any rate, the remainder of the presentation is
     basically what is going to be in these couple of documents
     that we're talking about.
               Mary is going to take it from here to talk about
     in general what will be in this attachment.  That will be a
     mixture of Mary and Rich and Gareth talking about the
               MS. DROUIN:  Mary Drouin, Office of Research.
               This attachment that is going to be to the SECY
     basically has three parts to it.  
               The first part is laying out what are those risk-
     informed activities where we feel PRA quality is an issue
     and needs to be addressed, because one of the things we want
     to do is come up with an integrated and uniform, consistent
     definition there that is going to be applied across these.
               Now we do recognize that PRA quality is variable
     with application but when we define what a PRA is, that
     definition of a PRA should be uniform and consistent, so we
     first are going to talk about what are those activities that
     this will be addressing and then Rich will get into NRC's
     decisionmaking process, how PRA and the quality of the PRA
     folds into our decisionmaking process and we'll get into
     that next.
               The last part of the attachment then gets into the
     details of what we consider to be technically acceptable in
     a PRA and then it has in there a discussion of what the PRA
     scope and level of analysis needs to be, the elements and
     characteristics of peer review, because that is one way to
     get to your technical acceptability.  
               The next one is we call it the PRA application
     process and that is intending to lay out the characteristics
     and attributes of a decision process in looking at what
     scope and elements you need for a specific application.
               The last one, laying out the attributes and
     characteristics of an expert panel, because in many cases
     you might be using an expert panel to supplement your PRA if
     your PRA doesn't cover the necessary scope or elements.
               DR. APOSTOLAKIS:  Could we attempt to define what
     a good enough PRA is for a particular application by saying
     that we make some decisions using that PRA in a particular
     context.  If one did a more detailed analysis the decision
     would not change.  In other words, that the decision is
               Shouldn't that be the ultimate criterion, because
     when you are dealing with these things you can't experiment. 
     You can't go and blow up things and see what happens. The
     only thing that makes a connection between risk assessment
     and whatever, with real life, the physical world, is the
     decisions you make, so that should be the ultimate criteria,
     that if somebody came back with a ten volume PRA for this
     issue, which you handled with three pages, the decision
     would not change.
               DR. KRESS:  It is like proving the negative,
               MR. CUNNINGHAM:  The decision might change.
               DR. KRESS:  Yes, you don't know whether --
               DR. APOSTOLAKIS:  Then it is not good enough.
               DR. KRESS:  You don't know whether the decision
     would change and so you have a never-ending set of things to
     worry about.
               DR. APOSTOLAKIS:  But this is the ultimate
     criterion though.
               MS. DROUIN:  I think there's a different way --
               DR. APOSTOLAKIS:  This is the ultimate criterion.
               MS. DROUIN:  I think there is a different way to
     look at it, George, in that you could lay out your minimum
     requirements for a PRA.  I think that would be very
     difficult.  That would cover every application -- 
               DR. APOSTOLAKIS:  Sure.
               MS. DROUIN:  -- because you could have an
     application that comes in that has nothing to do, where for
     example earthquakes have no effect --
               DR. APOSTOLAKIS:  That's right.
               MS. DROUIN:  -- and you might have a PRA where
     either it either didn't cover earthquakes or they did a
     lousy job.
               DR. APOSTOLAKIS:  That's what I mean, that they
     should really start from the endpoint, the decisionmaking
     process rather than starting by defining --
               MS. DROUIN:  And that is what we've done.
               DR. APOSTOLAKIS:  I don't dispute that.  I am just
     saying that --
               MS. DROUIN:  That is why that shows up first.
               DR. KRESS:  I think you ask yourself on the
     application do you have some PRA need for this application,
     an output of some kind, and then you have to ask yourself
     based on the decision I want to make how good do I need to
     know that number.
               DR. APOSTOLAKIS:  Right.
               DR. KRESS:  And if I only know it this well then I
     make one kind of decision, and if I know it this well make
     another one, and then you ask yourself the secondary
     question how good does my PRA give me so I can tie that to
     my need in the decision.
               I don't think you do what you do.  I think you
     look at them both in that kind of context.
               MS. DROUIN:  I think we are going to answer your
               MR. CUNNINGHAM:  Yes, you are jumping into Rich's
     presentation already basically, because he gets at many of
     the points that you raise, Dr. Kress.
               DR. WALLIS:  What I would like to do is make a
     distinction between going through the motions and the
     quality of the work.  This comes up in, say, codes, thermal
     hydraulics and so on.  You can make a structure where you
     have all the scope and level and elements, you have all the
     right things in there but then when you are actually
     modeling something you have to have equations, you have to
     have coefficients, and they have to come from somewhere, and
     the weak point of a lot of these things is they look good,
     but there is very little guidance on what the coefficient
     should be, where you could get them from, how you know if
     they are good enough, so the devil is in those sorts of
     details, not in the fact that the scope looks good and
     everything.  It's a different level.
               Do you have something to say about that level in
               DR. KRESS:  I think that is in your PRA elements
     and characterization.
               MS. DROUIN:  If you bear with us, we are going to
     get to that.
               DR. WALLIS:  That is part of the elements and
               MS. DROUIN:  Yes.
               DR. WALLIS:  Because you could have an element and
     it can be lousy.
               MS. DROUIN:  It could.  They could do it lousy.
               DR. WALLIS:  Okay.  You are going to tell us.
               MS. DROUIN:  So the point is that the paper has
     three parts.  They have been done sequentially on purpose,
     starting off with here are the activities, here is the
     decisionmaking process of how the PRA plays into that, and
     then it gets into the technical acceptability.
               So the first one is at a high level we view these
     more as areas where we feel that PRA quality is an issue and
     that the rest of the document would play into is risk
     informing 10 CFR Part 50, the plant oversight process, our
     operating events assessment and our license amendments, and
     all the different activities would fit into one of these
     categories where we think the PRA quality needs to be
               On that, I am going to turn it over to Rich to get
     into the decisionmaking process.
               MR. BARRETT:  I am Rich Barrett with Nuclear
     Reactor Regulation.
               I think a number of you have hit very early on
     what we think is a key point of all this paper and that is
     PRA quality is not something you can look at in isolation. 
     It is, as some have pointed out, dependent on what
     application you are looking at.
               I think more importantly it depends on your entire
     decisionmaking process and so what we intend to do in the
     paper is to address the decisionmaking process, the
     decisionmaking process that a licensee goes through to come
     to the application that they have submitted and the review
     process that the NRC goes through and the factors that we
     take into account in making those decisions.
               Ultimately what we are trying to do here is not to
     get quality PRAs.  Quality PRAs are a step toward getting to
     NRC reviews which allow us to make a finding, to make a
     finding that the risk is acceptable and that we understand
     the risk well enough that the risk can be bounded.
               What we have here is perhaps a seemingly complex
     spider chart which is intended to talk about some of the
     factors that we take into account in making a decision and
     in reviewing and accepting a licensee application, whether
     it is a license amendment or some larger application.
               If you go back and you read through Reg Guide
     1.174, and SRP Chapter 19, as I have done in the last month. 
               You will find that there is an impressive amount
     of information in there that would enlighten us in that
     particular area.  The people who drafted that document, and
     I was not one of them, did a very nice job of thinking this
     process through very carefully and I think maybe some of us
     have forgotten a lot of that information.
               What it basically says is that the Staff will
     review an application from the licensees.  We are not going
     to have cases where the existence of a peer review or the
     existence of a quality PRA will obviate the need for a Staff
               The question is what will the Staff review consist
     of, how deep will it be, how resource intensive, and where
     will it be focused.  In making those decisions where we want
     to start with is the question what is it that can give us
     assurance that the risk is in an acceptable range and that
     we understand the risk well enough to approve this
               In a simplified way there are really three factors
     that I think come into play.
               One of them is what I call, for lack of a better
     term, risk limitation.  There are cases where you can
     examine an application and in a qualitative way after you
     have looked at it come to the conclusion that your exposure
     to risk is limited, and that is an important piece of
     information to have before you ever go in and start looking
     at the PRA results with the quantification or anything else.
               The risk might be limited because of the nature of
     the change that is being made.  It might be limited because
     of the extent of the changes being made.  It could very well
     be that there are controls that have been placed on this
     application which limit. There could be backstops which
     again limit the risk exposure, and you need to understand
     those from the very start because that helps you not only
     decide how much analysis you have to do, but it can help you
     to focus where in the analysis you need to look.
               Even if the risk is limited, there might be some
     risk and you can understand where that risk is.  You know
     where to delve into the analysis.
               We think it is very important that that is the
     first place you look when you look at an application.
               CHAIRMAN POWERS:  Earlier today we discussed an
     issue in which a persuasive case was made that the
     probabilities of an event were very low, but that didn't
     deter us because we had -- there was not a characterization
     of the consequences and we had one of our members portray
     sufficient of a nightmare to us that it looked like those
     consequences were very big.
               When you use this word "risk" you really are
     looking at the products of these or are you only looking at
     the probabilities of an event?
               MR. BARRETT:  I think that if you make a
     qualitative judgment, I think my favorite example was that
     two years ago, the ACRS rightfully asked us to look at the
     potential risk significance of powerup rates in the BWRs. 
     There were five-eight percent powerup rates.
               And what we did was, we went in and we asked
     ourselves, what could be the impact of this on risk?  And we
     looked at both the probabilities and the potential impacts
     on consequences, things such as different amounts of fission
     products, perhaps the different effects on containment
               We looked at the probabilistic aspects, less time,
     perhaps, for operator reactions, maybe different success
     criteria for systems and operator actions.
               And we did look at a couple of plant-specific
     applications.  But by and large, we came to, I think, a
     pretty robust and qualitative conclusion that the risk from
     these small powerup rates was really quite limited.
               DR. APOSTOLAKIS:  So you looked at both,
     consequences and probability?
               MR. BARRETT:  Yes, you would have to look at
     consequences.  You can't allow yourself to get seduced into
     just looking at CDF and LERF, and perhaps you miss some of
     the other factors that impact risk.  
               DR. APOSTOLAKIS:  Maybe you need a better word
     than risk limitation.
               MR. BARRETT:  I would welcome a better term.
               DR. APOSTOLAKIS:  Risk implications or -- 
               MR. BARRETT:  Risk vulnerability.
               DR. APOSTOLAKIS:  Something, yes, because my mind
     went immediately to limitations of PRA, but that's not what
     you mean.
               MR. BARRETT:  Yes.  
               DR. APOSTOLAKIS:  Implications?  I don't know.  Do
     you plan to talk about this more, or do you want me to make
               MR. BARRETT:  I welcome your comments.
               DR. APOSTOLAKIS:  I would change this a little
     bit, and maybe combine the boxes, non-PRA insights and
     deterministic analysis into one and call it non-PRA
     insights, or traditional analyses.  I would avoid the word,
     deterministic, because a lot of it goes into PRA as well. 
               What you mean is the traditional engineering
     analysis that the Agency is used to.  
               And then I don't know why PRA has this honor of
     being peer-reviewed and the other stuff does not.  I would
     delete the boxes that says peer-reviewed, or everything is
               MR. BARRETT:  Everything, indeed, is peer-
     reviewed.  I mean, anything that is submitted to the NRC
     goes through some sort of a quality check.  What I was
     trying to highlight here is the role of PRA quality.
               DR. APOSTOLAKIS:  Okay.
               MR. BARRETT:  And there we're talking about the
     peer review which we're calling the certification process.
               DR. APOSTOLAKIS:  Yes, but you don't want to send
     the wrong message that you are imposing extra requirements
     on the PRA.  I mean, the other stuff will be -- but do you
     agree that perhaps the two boxes should be combined into
               If not, I would change the word, deterministic, to
     traditional engineering analysis.
               MR. BARRETT:  Well, I think -- which two boxes are
     you talking about?
               DR. APOSTOLAKIS:  Non-PRA insights and
     deterministic analyses.  
               MR. BARRETT:  No, those are two different things,
               DR. APOSTOLAKIS:  They are two different things?
               MR. BARRETT:  Yes, those really are.  I think in
     the case of the traditional deterministic analyses, what
     we're talking about there are questions of margin and
     defense-in-depth, and some of the traditional types of
     licensing questions that are issues that we bring into --
     the things that make this risk-informed instead of risk-
               Non-PRA insights really is non-PRA.  It should
     really say unquantified risk insights.
               DR. APOSTOLAKIS:  Oh.
               MR. BARRETT:  That's what it really should say.
               DR. APOSTOLAKIS:  Okay, so why don't we say that?  
               MR. BARRETT:  We will.  
               DR. APOSTOLAKIS:  And you agree to change the
     other one to traditional engineering analysis?  
               MR. BARRETT:  I understand that.
               DR. APOSTOLAKIS:  We had the same battle when you
     guys put together the diagram in 1.174.  Deterministic
     analysis feeds a lot into PRA.  
               DR. WALLIS:  It will become a traditional PRA
     analysis soon when it becomes a tradition.  
               DR. APOSTOLAKIS:  Engineering?  I don't know.  
               CHAIRMAN POWERS:  It's hard to find a valid -- 
               DR. SHACK:  PRA is not engineering?
               CHAIRMAN POWERS:  You're going to get him upset.  
               DR. APOSTOLAKIS:  I don't know what deterministic
     analysis is.  You mean the traditional licensing kind of
     analysis, but you don't want to call it that?
               MR. BARRETT:  Yes, I don't necessarily want to
     call it that, because we don't necessarily do it in the same
     way as we do licensing analysis when we're doing this kind
     of thing.  We may, in fact, do more best estimate than we
     would do in a licensing, in a case that was wholly based on
     licensing on deterministic design basis type events.
               But let me try to find better terms.
               DR. APOSTOLAKIS:  Yes.  
               MR. BARRETT:  Putting out a chart like this is
     difficult.  It's difficult to find the right words.  But I
     like unquantified risk insights.  I could just put down
     defense-in-depth in margins, how about that?
               DR. APOSTOLAKIS:  If you want to.
               MR. BARRETT:  Okay.
               CHAIRMAN POWERS:  Good.  
               DR. APOSTOLAKIS:  Well, actually, no, unquantified
     risk insights is better.
               MR. BARRETT:  No, I meant for the deterministic
               DR. APOSTOLAKIS:  Oh, yes, yes, that would be
               MR. BARRETT:  Okay.  Actually in the more complete
     version of this chart, that's what's in there.  
               DR. APOSTOLAKIS:  Defense in depth and safety
     margin considerations.  
               MR. BARRETT:  Okay, so we have PRA, unquantified
     risk insights, and defense-in-depth and margin
               DR. APOSTOLAKIS:  Right, and the peer-review is
     only for PRA, or do all three feed into a peer review?
               MR. BARRETT:  All three would fit into a peer
     review.  There would always be a quality review internal to
     a licensee before they submitted it, but the peer review
     process we're talking about here -- and maybe what I would
     do is just put in NEI 002 as meaning that this is what that
     box means.  
               That box means that these plants, these PRAs have
     been subjected to a peer review of that type.
               The second consideration before we get to the
     analysis part, is on the far right side here, which is
     performance monitoring.
               We frequently find that one of the best ways of
     limiting risk and assuring ourselves of safety is if we can
     find that the application has a good way of defining
     measures and criteria that can be monitored, real-time, to
     assure that the decision we've made does not lead to
     unacceptable consequences.
               Now, we've had a number of discussions as to what
     constitutes an acceptable performance monitoring program. 
     You have to have relevant measures; you have to have good
     criteria; and you have to be sure that you can detect
     unacceptable performance in a timely way before it becomes a
     risk and a public safety issue.
               But we do have examples where this is important,
     and so we need to look at this before we delve into the PRA
     as well.  So, having said all of that, and we then look at
     the analyses and we see that the PRA, the quantified PRA, is
     an important part of the analysis but it's not the only part
     of the analysis.
               The Reg Guide points us to other things such as
     unquantified risk insights and defense-in-depth, and margin,
     and other factors, operational experience and a whole wealth
     of information that can be brought to bear to give you
               DR. APOSTOLAKIS:  Should the box currently labeled
     risk limitation, also feed into the analysis?  I thought
     what you said earlier was -- well, maybe you didn't say it,
     but if you do this assessment of the significance of the
     issue you are dealing with, that will certainly affect your
               And right now it appears that it goes straight to
     the integrated decisionmaking, and the analysis is done
     independently of that.  In reality, it won't be.
               MR. BARRETT:  I think you could probably draw
     lines from all three of these in various directions.
               DR. APOSTOLAKIS:  Maybe that's a shell of the
     issue that you are dealing with, and everything else is
     within that.  You know, if you -- for example, if
     earthquakes is an issue that is irrelevant to the issue at
     hand, you're not going to ask a PRA to do an earthquake
               MR. BARRETT:  Right.  The idea of this is to look
     at the whole process from the bottom up, as to say the Staff
     -- you're the Staffer and you're reviewing the application. 
     What is it that you're going to be looking for?  And it
     doesn't get so much into the internal workings of the
     licensee and how they went about making their decisions.
               DR. APOSTOLAKIS:  And the other point I want to
     make is that I congratulate you on spelling decisionmaking
     process correctly, as opposed to the ACRS Staff that makes
     it one word.  It drives me up the wall.  
               MR. BARRETT:  We'll accept any comment.
               DR. APOSTOLAKIS:  Even at the expense of your
     colleagues here.  
               DR. SIEBER:  They actually have it both ways on
     that chart, so you can use.  
               DR. WALLIS:  Which one do you think is correct,
               DR. APOSTOLAKIS:  They hyphenated one.
               DR. KRESS:  George, I will offer an opinion on
     this weighty subject that both ways are correct, and they
     used them correctly both there.  In the integrated
     decisionmaking, it is a noun; it is a thing.  Up there, it's
     an adjective talking about the process, and it's an
     adjective, so they've used it correctly.
               DR. APOSTOLAKIS:  These guys used it.
               DR. KRESS:  These guys used it -- 
               DR. APOSTOLAKIS:  But in our records, we don't.
               DR. KRESS:  Maybe not, but here it's used
     correctly both times.
               DR. APOSTOLAKIS:  Decisionmaking process in our
     letters is one word, decisionmaking.
               MR. MARKLEY:  George, we do it both ways also.  
               CHAIRMAN POWERS:  I think we can move on.
               DR. KRESS:  Before you move on, though, I would
     like to be more substantive.  I would like to see that
               Now, what I envisioned, Rich, is that you have
     some sort of decision to make about some change, and whether
     or not its acceptable.
               And you're going to have some criteria to guide
     you on whether it's acceptable or not.  And some of that
     criteria may be, does it meet certain risk levels.  And if
     it doesn't, you'll have to have a PRA or some sort of way to
     judge what the risk implications are.
               But your decision as to whether it's acceptable or
     not, may depend on what quality of PRA you have in
     determining that, and it may or may not be acceptable, but
     if the quality is not very good of the PRA, you could offset
     that by having performance monitoring, more defense in depth
     and bigger margins, so that the integrated decisionmaking
     and these other things are all tied to the quality of the
               If it's a poor quality, you have to have more
     performance, you have to have more defense-in-depth, better
     margins, so that the way I view it is that you have a set of
     basically a matrix of criteria that, depending on what
     quality of PRA you have, you will have an acceptance
     criteria that depends -- that varies these other things.  Is
     that a way to look at this?
               MR. BARRETT:  If I was a licensee -- well, as a
     regulator, I think I look at these three areas as being
     tradeoffs, making tradeoffs.
               If I was a licensee, I would think in terms of
     iterating.  That is to say, if I could not, myself, make the
     arguments that risk is limited, or that I could perform as
     monitor, and yet I didn't think that I had the sufficient
     quality of PRA, I might go back and put controls on this
     thing or backstops on the applications so that I could
     further limit the risk, or I might go back and look harder
     for some way to monitor performance.
               DR. KRESS:  Or put more defense-in-depth in so
     that the actual risk numbers you get are coming down or
     something like that.  
               DR. SIEBER:  If you were writing risk-informed
     rules, this would be the model that you would want to use to
     set up how those rules and all the supporting documents like
     Reg Guides and so forth would be, because it should, in my
     view, have a risk expectation associated with the rule, and
     a way to monitor performance to make sure that the input
     assumptions to the risk analysis are correct.
               And so this then becomes the model.
               DR. APOSTOLAKIS:  That's what 1.174 does.
               DR. SIEBER:  Well, this is the model for risk-
     informed rulemaking, which is one of the tasks that's ahead
     of us in the near future. 
               MR. PARRY:  I think this gets back to the question
     that you raised earlier; that if you had a -- if you could
     define a quality of PRA, then you could  -- I don't know the
     way you phrased it, exactly.
               But you'd say this is the -- once you've got that
     and you've got a robust decision.
               I think you can look at it a different way, which
     we haven't quite addressed yet.  And again, it's to do with
               The more confidence you have in PRA results, so
     whatever that role -- whatever the role of the PRA is in the
     decisionmaking process and it's balanced on these three legs
     that Rich has got in this diagram, the more confidence you
     have in the PRA results, then perhaps the less conservative
     you can make your decisions.  
               So I think that if you look at it in terms of
     Option 2, for example, the more confidence you have in your
     PRA -- in the PRA results that you're using, then perhaps
     you can shift more components into one box rather than
     another.  So it's not a matter of making a robust decision
     at that level; the decision may change.
               DR. APOSTOLAKIS:  I still think I can place what
     you said in the context of my interpretation, in the sense
     that the decision is not robust if based on this current
     state of knowledge, somebody feels that you have made a
     conservative decision, and by doing more analysis, that
     person feels that he can convince you that that's the case.
               So then your PRA is not adequate for the
     application.  I think ultimately what drives it is the
               MR. PARRY:  Yes, but I think it depends on what
     you want to get out of it.  
               DR. APOSTOLAKIS:  I think we understand that.  In
     fact, that's the point of Rich's comment when he addressed
     the risk limitation there.  You know, let's not forget where
     we are and what kind of decision we're about to make, and
     then we jump into the analysis.  
               MR. BARRETT:  I guess the last point I want to
     make on this slide is the importance of the staff's review
     of NEI 0002, and the allied process for risk categorization,
     because, in reality, we are going to be faced with PRAs that
     have been subjected to this peer review.  That is going to
     be our tie to what is actually in the industry.  And, so, it
     is very important, as Mary said earlier, that we have a
     common set of expectations that we apply to this peer review
     process and that we apply to our review of the ASME
               DR. KRESS:  And when you say PRA here, this could
     be a PRA that has associated with it a fairly robust
     uncertainty analysis, or it could be one of these nominal
     PRAs that we call best estimate, for whatever that means,
     without uncertainty.
               DR. APOSTOLAKIS:  Could be.
               DR. KRESS:  Are we including both of those as the
     definition of what a PRA is?
               MR. BARRETT:  I think the logic that we are going
     to apply is that we are going to, and Mary is going to talk
     about this in just a minute, we are going to lay down our
     expectation of what is a PRA.  And then the second question
     we are going to ask is, does the -- to what extent does the
     NEI peer review process give us the assurance that a PRA
     meets that standard?  And it may give us 90 percent
     confidence, it may give us 100 percent confidence.  We need
     to understand how much confidence it gives us and we need to
     understand where the deltas are.  And then with that, armed
     with that knowledge, we can go forward to specific
               DR. APOSTOLAKIS:  I would say, Tom, that there are
     many cases where you really don't need an uncertainty
     analysis.  It really is very problem-specific.  You don't
     need an explicit quantitative analysis, you always do it in
     your mind, of course.  But that is a lesson that I think one
     can learn from actual applications, that you don't always
     need it.  But, anyway, we will see when it comes.
               DR. POWERS:  George, do we have enough cases
     before us where people have done explicit uncertainty
     analyses that we are justified in drawing conclusions on
     when and where you don't need uncertainty analyses?
               DR. APOSTOLAKIS:  First of all, it depends on what
     we mean by uncertainty analysis.  What I mean is the
     traditional failure rate type of thing.  Yes, when people
     realized that jumping into a full scope, complete
     uncertainty analysis PRA was too expensive, they started
     doing it in phases.  
               The first phase was, you know, using insights from
     other PRAs and rough point estimates just to rank things. 
     Very rarely, the insights regarding what is important from
     this point estimate calculation were upset by a detailed
     uncertainty analysis, I will say.  You pretty much had the
     good grasp of the major accident sequences most of the time. 
     And then you refine it and you refine it, you go down to
     more detail and so on.  So, there are insights, important
     insights you can gain without going through the whole
               DR. POWERS:  But I guess when I think about
     detailed uncertainty analysis and PRAs, and where I have
     seen them, they come up with very few.
               DR. APOSTOLAKIS:  Very few what?
               DR. POWERS:  Very few examples.
               DR. APOSTOLAKIS:  Of complete uncertainty
               DR. POWERS:  Any kind of uncertainty analysis at
               DR. APOSTOLAKIS:  Well, the PLG, PRAs are full
     uncertainty analysis.  How many have they done?  I don't
     know.  I am sure others have done it, too.
               MR. PARRY:  I think, though, where the uncertainty
     analysis is most important is when you are making the
     decision.  And I think even if you look at -- it needn't be,
     as you say, a full quantitative uncertainty analysis.  If
     you can understand what the sources of the uncertainties
     are, this is what Reg. Guide 1.174 says, understand the
     sources of uncertainty and see how they impact the decision.
               In fact, if you look at the NEI guidance on
     categorization, you will see elements of that in that
     process.  An example of what they do is for -- they will do
     the categorization according to Rohr and Fussell-Vesselly. 
     But they will also ask you to do sensitivity studies to vary
     some of the parameters that are perhaps the more
     controversial parameters, and then use the results of those
     to adjust the categorization.  And I think that is an
     appropriate use of uncertainty analysis in the context of
     your decision.  I don't think you have to have a PRA that
     has fully quantified everything to play the game for many of
     these things.
               DR. POWERS:  Well, I guess what I am asking is,
     you somehow have reached this judgment that these
     sensitivity studies and varying some of the parameters is
     somewhat adequate for the -- 
               MR. PARRY:  It is adequate.
               DR. POWERS:  That it is potentially adequate.
               MR. PARRY:  Right. 
               DR. POWERS:  And what I am asking is, have we had
     enough people do something that is akin to what they tried
     to do in 1150?  Has that been done often enough that I can
     use a judgmental, that I can develop some judgment on when
     something much less than that is adequate.  And George says
     that -- he is a bright guy, and he has seen a lot of these
     things, and he says, gee, I can get all the insights I want
     with very little.
               DR. APOSTOLAKIS:  Not all.
               DR. POWERS:  I am not nearly so bright, but I do
     get to do a lot of uncertainty analyses on deterministic
     models, and I am always stunned at what I find to be the
     influential parameters.  I am 0 for 10 in outguessing the
               MR. PARRY:  But those are very nonlinear systems.
               DR. APOSTOLAKIS:  Very nonlinear systems, plus
     what you say about the number of studies.  Yes, in level 1
     PRAs for internal events, there are many of them, both
     nationally, internationally, so things are beginning to
     converge to a certain picture.  You know, you sort of expect
     to see certain things for PWRs.  We had this wonderful
     compilation of insights from IPEs that Mary put together. 
     Yes, there is a wealth of experience there.  You are not
     going to be surprised.
               DR. POWERS:  Well, I think of this wonderful
     compilation that Mary put together, an outstanding piece of
     work, that I continue to refer to, but, unfortunately, some
     of its most influential graphs which show the range of
     results obtained from a variety of analyses do not have
     uncertainty bars on them.  And it makes it very difficult
     for me to interpret the significance of the range of core
     damage frequencies among PWRs if I don't have those
     uncertainty bars there.
               DR. APOSTOLAKIS:  And that may be an instance
     where you have to do uncertainty analysis.  All I said was
     that sometimes you get very useful insights without an
     uncertainty analysis.
               DR. POWERS:  Well, what I end up doing -- 
               DR. APOSTOLAKIS:  And this is the major
     contributors to risk.  I don't think that if you do the
     point estimate and then you go and round your uncertainty
     calculations, you are going to upset the order that much.
               DR. POWERS:  See, what I end up doing is I take
     Mary's plots and I use them as an ensemble.  And I say --
     and, so, somebody does a -- gives me a result from a PWR, I
     plot it, put it on Mary's plot, and I say, now that is the
     uncertainty that I am going to have to make my decisions in,
     because it is the ensemble.  It is the only thing I have got
     to go by.
               DR. APOSTOLAKIS:  I don't know what to say to
     that.  I mean you need uncertainty analysis there, what can
     I tell you.  All I said was there are instances where you
     don't.  You can have 80 percent of your insights by doing a
     very quick calculation with point estimates, that is all.
               MS. DROUIN:  And I think if you also go to those
     wonderful plots, and you look at the outliers that are
     forming the bands, you may not have uncertainty analysis on
     them, but on those few outliers you tend to have sensitivity
     studies and know what the effect of those things are, there
     is sensitivity analysis.
               DR. POWERS:  Well, you try to communicate it in
     your document.
               MS. DROUIN:  And you know why they are outliers.
               DR. POWERS:  Why they are there.
               MS. DROUIN:  So you are getting the same
     information.  You are getting the information that you need
     to know.
               DR. APOSTOLAKIS:  Are you going to discuss
     uncertainty soon, or this is it?
               MS. DROUIN:  I'm sorry?
               DR. APOSTOLAKIS:  Uncertainty analysis.  Is it
     going to be discussed separately today?  Or we are
     discussing it now?  I mean is there a slide?
               MS. DROUIN:  Not as a specific topic, as a slide,
     no.  You might see one.
               DR. APOSTOLAKIS:  I think -- then let me make one
     last comment.
               MS. DROUIN:  But I will show -- 
               DR. APOSTOLAKIS:  If you have later, that is fine,
     I will wait.  Do you want me to do it now or later?
               MS. DROUIN:  Do it later.
               SPEAKER:  Much later.
               DR. POWERS:  Let's go on.  I think we have spent
     enough time on it.
               MS. DROUIN:  How about when we get into the slide
     where it will be addressed, even though it is not a specific
               MR. BARRETT:  Let's skip -- I want to skip to page
     12.  The intervening pages have all been discussing.
               DR. APOSTOLAKIS:  Oh, wonderful.  You should come
     here more often, Rich.
               MR. BARRETT:  Doesn't that feel good when you get
     to skip over some items.  What I have tried to do is just
     work through three examples.  What these examples are, what
     I have tried to do is pick three examples which are kind of
     extremes.  One in which you are principally relying on the
     analysis for your assurance.  One in which you are
     principally relying on your qualitative judgment that the
     risk is low.  And one in which you are relying primarily on
     performance monitoring.  
               And, unfortunately, in our last minute rush to
     make this slide, we didn't quite get it right.  So, I am
     going to -- what I want you to do is, on that -- what I have
     done here is basically say, if you see the word "high," what
     that means is that there is high reliance on that factor. 
     So risk limitation, high reliance that there is a limited
     risk.  High reliance on the analysis, or high reliance on a
     good performance monitoring program.
               The intent of the first example was to refer to
     the risk-informed standard tech specs, or, in general, the
     use of risk for configuration management.  Now, you could
     call the use of a risk monitor, or you could use the example
     of the industry's proposal to take A-4 of the maintenance
     rule and the tech specs and rationalize those into a single
     set of requirements that are risk-informed, or you could
     refer to element 4 of the risk-informed standard tech specs,
     which is a proposal for licensees in a -- who reach a LCO, a
     limiting condition for operation, to use their PRA or use
     their risk insights to decide what their end state will be.
               Any of these examples of using your risk methods
     to determine the configuration of the plant, we would say
     that in those cases, the risk limitation is low.  You
     really, you can't say that it is very limited, because the
     possibility is that you could stray quite a bit from a good
     configuration if you don't have a good PRA model.  So we
     would say this is an example where you really have to have
     high consequences -- high confidence, rather, in your
     analysis methodologies.  You cannot limit -- you can limit
     the risk, but it is very difficult to limit the risk, and it
     is very difficult to monitor the performance in a timely
     fashion.  So that is an example where you really have to
     have consequence -- high confidence, I keep saying high
     consequence, high confidence in your methods.  And not only
     your PRA, but your risk management method.
               The second example is risk-informed ISI.  Having
     done the pilots and having done the topicals, the
     Westinghouse Owners Group topical and the EPRI topical, we
     have come to the conclusion that the exposure, the risk
     exposure of this type of an application is not that high. 
     What you are basically doing is you are using risk as one of
     two criteria for sampling the piping that you are going to
     look at to try to determine if you have a problem with the
     welds.  And it is good to choose piping in high risk areas,
     it is also good to use the other criterion, which is to
     sample piping in areas where you expect to see degradation,
     but you are not very vulnerable to any error that you might
     make in selecting those areas.  So that is -- 
               DR. APOSTOLAKIS:  Why is it high?
               MR. BARRETT:  We are saying that there is a high
     confidence that we can accept this application based on the
     low risk exposure.  Okay.  And we are not -- 
               DR. APOSTOLAKIS:  It means that you have high
     under tech spec and high under risk-informed ISI.
               MR. BARRETT:  Yeah, unfortunately, what that
     should say in the first line is "low."
               DR. APOSTOLAKIS:  Okay.
               MR. BARRETT:  All right.  Sorry.  In our haste to
     make the slide, we got it wrong.
               DR. APOSTOLAKIS:  No, that is fine, as long as you
     tell us what it should say.
               MR. BARRETT:  It should say "low," "high" -- 
               DR. APOSTOLAKIS:  Okay.
               That's a case where you are defending -- well, we
     have made that conclusion and we are not going to be asking
     licensees for tons and tons on --
               DR. APOSTOLAKIS:  As I recall the analysis,
     actually, if you put there "nonexistent" that would be okay
               MR. BARRETT:  And the third example are the steam
     generator tubes where you know that you cannot say that you
     have high confidence that the risk is low because you are
     talking about something that represents two of the barriers.
               The potential is there for high risk if you don't
     have a good handle on steam generator tube degradation so
     you are either going to have to have very high confidence in
     your analysis methodologies or you are going to have to
     place confidence in your ability to monitor performance in a
     timely way.
               DR. APOSTOLAKIS:  So tell us what the correct
     words are.  Risk limitation is what?
               MR. BARRETT:  The risk limitation is low.
               DR. APOSTOLAKIS:  Analysis, medium?
               MR. BARRETT:  We think that in this particular
     case, if you have been following, and I know you have, NEI
     97-06, we are putting our eggs in the basket of performance
     monitoring.  We think that if you understand what the
     licensee finds at the end of a cycle, and then there's
     timely feedback into their ability to predict what is going
     to happen in the next cycle that that is where you are
     getting the risk limitation.
               Without going into a great deal of detail, what we
     have here is three different examples of risk-informed
     applications where the confidence that you gain is from
     three different parts of the triad but in most cases we
     tried to work about six or seven other examples and none of
     us could agree where to put the highs and lows and mediums,
     so some of the other applications are not quite so simple.
               The reason they are not so simple is because they
     can interact, because you can, if your PRA isn't good enough
     to do what you want to do then you will limit what you want
     to do, so there are tradeoffs.
               CHAIRMAN POWERS:  I find these examples
     illuminating. I hope in your document you are going to have
     several others in there, and it is illuminating in that it
     tells me the kinds of applications where you think you are
     going to be getting risk based applications in and it adds a
     little more meat to the concept of integrated decisionmaking
     that you are not just relying on the PRA to give you an
     answer, so I find this a useful slide.
               MR. BARRETT:  Thank you.
               DR. APOSTOLAKIS:  A low risk limitation means that
     the risk is potentially high?
               MR. BARRETT:  Right.
               DR. APOSTOLAKIS:  Okay.
               CHAIRMAN POWERS:  You might work on your risk
     communications a little bit.
               MR. BARRETT:  I have got to work on these two
     slides. That's all.
               DR. KRESS:  I think we had something like this,
     George, in our joint letter where we said that if you have
     an application where the inherent hazard or risk is fairly
     low that you don't have to have that good of a PRA and you
     could rely mostly on just performance and looking at how it
     goes, but if you had inherently a pretty high risk then you
     better have a pretty good risk analysis and your performance
     monitoring might --
               CHAIRMAN POWERS:  I am still struggling on when
     can I look at just the frequencies of accidents and I don't
     have to look at the product of those frequencies and
               DR. APOSTOLAKIS:  No, you always look at both.
               CHAIRMAN POWERS:  There must be some probability
     that I don't have to --
               DR. KRESS:  I am sure there is, Dana.
               DR. APOSTOLAKIS:  The consequences are huge -- no,
     no, the whole business here is called low probability, high
     consequence events.  I mean you have to look at both.
               DR. SEALE:  PTS comes close to that, Dana.  You
     said that it is so low that you don't --
               CHAIRMAN POWERS:  That's a good point --
               DR. APOSTOLAKIS:  But you know the consequences.
               DR. SEALE:  Not in their glory, you don't.
               CHAIRMAN POWERS:  You have a worst case.
               DR. SEALE:  Yes, that's right.
               DR. WALLIS:  The problem I have, Rich, with this
     very nice matrix, nine entries in it, is what does this tell
     me about the PRA quality subject, and I thought it was in
     the analysis somewhere, but that is only part of the
     analysis.  I don't know what this tells me about PRA
               MR. BARRETT:  What this tries to do is to remind
     everyone that when you look at PRA quality, and Mary is
     going to talk to you in a lot more detail about PRA quality
     itself, but you need to look at it in the context of other
     factors.  That's basically what it does.
               DR. WALLIS:  Does it mean that if I have a low in
     analyses I don't need a good PRA?
               MR. BARRETT:  It may very well be that you don't
     need that -- well, from my perspective as a manager in NRR,
     it may well be that I don't have to concentrate the kind of
     resources on the review of that PRA that I might otherwise
     have to do.
               DR. APOSTOLAKIS:  Maybe using the word "quality"
     is not appropriate here.  It seems to me we are talking
     about scope.  You can't mean that you will accept something
     of poor quality because its significance is not high.  That
     doesn't make sense.
               You are accepting something that is of smaller
     scope.  Maybe they don't do uncertainty analysis.
               MS. DROUIN:  Right.
               DR. APOSTOLAKIS:  Maybe they don't do the human
     error very well, quantification, otherwise I agree with Dr.
               MS. DROUIN:  We always expect them when they --
               DR. APOSTOLAKIS:  I mean you can't say the quality
     is poor but I accept it anyway.
               MS. DROUIN:  We expect them to do their arithmetic
               DR. APOSTOLAKIS:  Of course.  It is the scope that
     is different.
               MS. DROUIN:  Correct.
               MR. PARRY:  Quality has to be appropriate for the
     use that is made of it in this decision.
               DR. APOSTOLAKIS:  But when you say quality you
     really mean scope, I think.  You can't mean that they are
     allowed to miscalculate things --
               MR. PARRY:  No, they have to follow certain basic
     rules but it's scope, level of detail, level of
               DR. APOSTOLAKIS:  That is the scope.
               MS. DROUIN:  For the scope that applies to the
     decision being made --
               DR. APOSTOLAKIS:  Right.
               MS. DROUIN:  -- the scope has to be done, the
     technical analysis for that scope has to be done correctly.
               DR. APOSTOLAKIS:  So the quality is still good.
               MS. DROUIN:  The quality is still good.
               DR. APOSTOLAKIS:  It is just a different scope.
               MS. DROUIN:  For the scope that doesn't apply --
               DR. SEALE:  You can't get blood out of a turnip.
               If the information is not in the analysis you
     can't make it be there.  I mean if you don't know enough to
     give yourself useful numbers from a PRA point of view about
     steam generator tubes, you can grind those numbers till the
     cows come home and you are still not going to get any more
     than what you got.
               DR. APOSTOLAKIS:  I really think that using the
     word "quality" the way we have been using it has created
     some confusion.
               MR. CUNNINGHAM:  We agree.  I think it is a
     shorthand that we use.
               DR. APOSTOLAKIS:  Scope and detail is really the
     appropriate --
               MS. DROUIN:  As we go forward, you will see that
     we have tried not to use the word "quality."
               MR. BARRETT:  But there are gradations, even in
     terms of data.  How recent is your data? How plant-specific
     is your data?  There are gradations in quality and you --
               DR. APOSTOLAKIS:  That is a borderline issue,
     you're right, but I can still call it the scope and detail.
               MS. DROUIN:  Okay.
               DR. APOSTOLAKIS:  Ohhhh -- raise it up a little
     bit, otherwise we'll gave Gareth's head blocking everything.
               MS. DROUIN:  I'm sorry.
               MR. PARRY:  You need to raise the slide a little
               MS. DROUIN:  Better?
               DR. APOSTOLAKIS:  Yes.
               MS. DROUIN:  Okay.  In looking at the technical
     acceptability of the PRA that is going to support your
     decisionmaking process, I think there is a process for
     determining what that technical acceptability is. That is
     what is shown here in that shaded box. 
               You are trying to get risk insights out of the
     PRA, this process to support your decision, and there's
     steps here going through starting off with what your PRA is
     and then looking at it and determining what is the
     appropriate scope that you need to support those risk
               You are either going to be in scope or you are
     going to be out of scope.  If you are in scope, then what
     are the elements in the characteristics that are needed to
     support that scope and then imposing a peer review to
     confirm that technical acceptability, and then coming out of
     the peer review and you look at the results from that if
     they are acceptable you are going over to an expert panel to
     integrate your risk insights.
               If it is not acceptable then you are going to go
     through some decision process on what to do with this
     unacceptability and the unacceptability might be an
     insufficiency or it might be a difference or it might be
     something missing, because you can also get there because
     you are out of scope, but you would have some kind of expert
     panel input there too, and then you would go also back to
     the expert panel to integrate your risk to come through --
     to generate your risk insights.
               I kind of glossed over this quickly but I am going
     to go through each one of these boxes.  I am just kind of
     laying the stage here to show you how it all fits together
     and hopefully as we go through these individually the flow
     chart will start to gel and make some sense.
               So if we start at the beginning we first lay down
     independent of the application at this point, what is the
     scope and level of analysis for a PRA.  You want to call it
     a PRA.  We're saying here is what the scope and level of
     analysis is and starting off with your plant operating
     states the PRA is going to look at your full and low power
     and your cold and hot shutdown.  You want to capture the
     entire risk.
               On your initiating events, you want to consider
     both internal and external events.
               DR. APOSTOLAKIS:  Let me understand this.  All the
     time you have to do this?
               MS. DROUIN:  No.
               DR. APOSTOLAKIS:  Oh.
               MS. DROUIN:  No.
               DR. APOSTOLAKIS:  Okay.
               MS. DROUIN:  We are going to get back to that.  We
     are just saying right now if you call something a PRA this
     is what we are calling a PRA and the PRA is going to
     characterize your risk and we are looking at Level 1, core
     damage frequency, Level 2, LERF and including late
     containment failures, and we are not including Level 3 in
     defining what we mean by a PRA.
               DR. APOSTOLAKIS:  So you are beginning now to put
     fires under internal -- that's very good.
               MS. DROUIN:  We have been doing that for a long
     time now, George.
               DR. APOSTOLAKIS:  Really?
               MS. DROUIN:  Yes.
               DR. APOSTOLAKIS:  But you kept it a secret from
               MS. DROUIN:  Well, I didn't mean to.
               DR. SEALE:  Earlier today we'd been talking about
     our frustration about not having the consequences included
     in the result of an assessment or that we didn't carry the
     so-called risk determination to the point of assessing
               It would appear that you are adopting that
     practice as standard.
               MS. DROUIN:  I will say what you are seeing now is
     preliminary, you know, and that is why you do not have, you
     know, the attachment to the SECY, because we are still
     formulating, we are still going through and discussing among
               DR. SEALE:  Yes.  The reason I mentioned it is, as
     I said earlier, we had some frustration with the fact that
     consequences were not a product of some of these so-called
     risk assessments and so this may very well be a concern we
     would have with this definition of what you have indicated
     on the risk characterization.  You really haven't come up
     with consequences.
               MS. DROUIN:  Correct.
               MR. BARRETT:  If I could say a word about that,
     this is something that we are grappling with right now in
     the context of Option 2 and in the context of the pilot for
     Option 2.
               That is, how do you categorize equipment that has
     no impact on CDF or LERF, equipment such as containment
     sprays, containment of fan coolers, filter systems,
     ventilation systems, and as you get to Option 3 things like
     containment leakage requirements and in fact we have already
     been dealing with these in license amendments.
               I think I would agree with Mary. I don't think
     that the right way to do that is to go to a full Level 3
     PRA.  That is a lot of effort and expense to try to deal
     with that issue, but we are trying to figure out a way of
     dealing with that issue.
               DR. SEALE:  But you can't ignore it though.
               MR. BARRETT:  We are trying to figure out a way of
     not ignoring it but at the same time not placing a burden on
     the PRAs that I don't think they can meet right now.
               MR. SIEBER:  Those are really defense-in-depth
     kind of features for the most part.
               MR. BARRETT:  Yes, they are, but if you play the
     defense-in-depth card and you say because of defense-in-
     depth I need all of this stuff and I need all of it to be
     gold-plated, you are not putting it on the same footing as
     everything else.  We are trying to come up with a way to put
     it on a similar footing so that you have some criterion that
     you can use that is comparable to CDF and LERF to make these
               MR. SIEBER:  Would you postulate that perhaps some
     defense-in-depth features would then disappear because they
     don't have an impact?
               MR. BARRETT:  I think whatever decision you made
     you would want to keep into account defense-in-depth.
               For instance, suppose a licensee came in and said,
     well, you know, we think we can live with higher
     consequences offsite from a TMI type of accident.  What
     would be the considerations?
               The considerations might be reductions in your
     requirements on mitigating systems like sprays.  It might be
     a reduction in your requirements on the leak tightness of
     the containment, or it might be a reduction in some of the
     gas treatment systems.  In a sense, you might want to make a
     decision like that considering the defense-in-depth, so you
     might not say, well, I am not going to take away this or I
     am not going to take away that, but I might allow you to
     relax some of those, so you still have defense-in-depth but
     you have used some criterion to accept some relaxation.
               MR. SIEBER:  But in the case of containment
     leakage the probability doesn't change.  The consequence
               MR. BARRETT:  Exactly.
               MR. SIEBER:  And so if you don't look at Level 3
     in the consequences, it doesn't show up.
               MR. BARRETT:  We try to deal with it qualitatively
     or at least --
               MS. DROUIN:  This was a very poor choice of words. 
     When we were saying not required, it did not mean to imply
     that we weren't concerned about the consequences.
               All we were trying to day by that is that we were
     not going to require a Level 3 PRA, so that was very
     misleading there.
               MR. SIEBER:  But the consequence to the public
     doesn't appear in either CDF or LERF either.
               DR. SEALE:  Have you entertained the idea of a so-
     called standard cite?
               MR. BARRETT:   He has gone that far.  You know in
     past applications, let's take the example of the
     Decommissioning Technical Report. What we tried to do there
     was to look at a couple of types of sites, a high population
     site. We picked a specific site. We postulated a site where
     the uniform density -- you know, we tried to do it on a
     generic basis without going to the extent of asking every
     licensee that decommissions to have a level three PRA.
               MR. WALLIS: Richard, your subject is PRA
     qualitative.  If I look at this, I say, "Well, how does this
     help me access PRA qualities?"  I look at this thing and I
     say "Well, this PRA that I have here doesn't have
     (inaudible) in it and I think it should have, therefore, it
     is of low quality" just to live a check list.  If I need to
     evaluate for full quality purposes or how does it --
               MS. DROVIN: It depends on the application.
               MR. WALLIS: How does it affect my decision about
     whether or not this PRA is of sufficient quality.
               MR. CUNNINGHAM:  In a sense yes, though.  It is
     kind of a first screen. You are expecting to see initiators
     of these types and if you get a PRA submittal and a missing
     logo or something like that. It's again --
               MR. WALLIS:  Then I would want to know why.
               MR. CUNNINGHAM:  And is it important to the
               MR. APOSTOLAKIS:  One question.
               MS. DORVIN:  We're going to have a slide on that.
               MR. APOSTOLAKIS:  Is level two really this
     definition?  I thought level two was the source there;
     wasn't it?
               MR. CUNNINGHAM:  Yes, that's right.
               MR. APOSTOLAKIS:  So this is a variation.
               MR. KRESS:  That's a one plus.
               MR. CUNNINGHAM:  This is Level one and a half --
               MR. APOSTOLAKIS:  This is a level one plus.
               MR. KRESS:  That is what we call it.  Yes.
               MR. APOSTOLAKIS:  Well, the Germans call something
     else level -- This is new level two perhaps, I don't know.
               MR. KRESS: (Inaudible), maybe.
               MR. APOSTOLAKIS:  Level two minds.
               MR. KRESS:  It looks at containment cellular
               MR. APOSTOLAKIS:  Just containment, not the actual
               MR. KRESS:  It is not exactly true that this
     doesn't have consequences in it because LERF is a measure of
               MR. CUNNINGHAM: LERF. Sure.
               MR. KRESS:  If you have it there.
               MR. PARRY:  Can I just add something to respond to
     Dr. Wallis.  I think the way you have to look at this.  This
     is really just a bit of semantics. It helps you define what
     your PRA contains. So when you come to judge the quality of
     the PRA, I think you have to judge it in terms of the
     quality given the scope of the PRA and given the results
     that it is providing for the decision making. So this is
     just really -- you don't say that a PRA is of low quality
     because it has low power and shut down, because it doesn't
     have low power and shut down in it.  If you recognize that
     one, you're making a decision, and you compensate for that
     then you have used the results appropriately.
               MR. WALLIS:  So it doesn't meet the
     specifications. I would put it that way.  Do you need the
     PRA's for some purpose?
               MR. PARRY:  I think what the decision, like for
     example, if we were doing something according to REGI 1174,
     what it says is that you look at all contributions to risk. 
     Okay, low power and shut down on internal and external
     events.  If you happen to have a PRA that doesn't cover all
     those things, then you would have to limit the role that the
     PRA analysis plays in the decision making.  But within that
     context, you can still ask the question of the PRA for the
     use that it is being made of in the decision.  It's no
     reflection on the quality of the PRA that it does not have a
     full power -- a low power and shut down portion to it.
               MR. SEALE: That's why it's --
               MR. POWERS: It seems to me --
               MR. PARRY: That why I think we've talked about we
     don't want to (inaudible) quality in a bad way.
               MR. POWERS: It seems to me that you are working
     here at a fairly high level and I might, as a commissioner,
     say it doesn't really matter about this stuff, none of the
     PRA's have most of the things in them anyway. Tell me about
     the ones that we actually have which are full power PRAs and
     what you are requiring there.  And I might ask questions
     like: Is it all right for you guys to get a PRA that works
     only at the system level, or does it have to go to the
     training level or does it have to go to the component level? 
     Are you going to address those kinds of questions?
               MS. DROVIN: Bear with us.
               MR. BARRETT: Yes.
               MS. DROVIN: I mean we are just starting at the
     beginning first saying --
               MR. POWERS: I understand.
               MS. DROVIN: -- saying what the scope of the PRA
     and again, we are not saying that for every application the
     scope needs to be this.  Remember I said this is independent
     of the application.  We're just saying --
               MR. POWERS: This is my checklist on what it's
               MS. DROVIN: For a PRA this is the scope we are
     looking at.  And we wanted to define --
               MR. BONACA: I have a question about-- I am sorry.
               MS. DROVIN: -- the details for this scope. Yes.
               MR. BONACA: Do you consider (inaudible) accidents?
               MS. DROVIN: Yes.  But we're not covered here. If
     you went back, we're just talking about reactor activities.
               MR. BONACA: But you are going to have that
               MS. DROVIN: At some point, yes.  Right now, I
     mean, Tom if you wanted to address that --
               MR. KRESS: No. No.
               MR. BONACA: No, no.  I just am saying that, you
     know, I mean, I know that a lot of PRAs do not include
     (inaudible) pull accidents, since we've been talking about
               MR. POWERS: I don't know of too many that do.
               MR. KRESS: That's right.
               MS. DROVIN: No. We're strictly focused on the
     reactor right now.
               MR. PARRY: Right now this is the reactor.
               MR. BONACA: And since you are looking at full low
     power and shut down, and you have operations there that
     include transfer to the pool, things of that kind, I would
     expect that would be part of the scope of a complete PRA.
               MS. DROVIN: Ultimately, yes. But right now we're
     just looking at the reactor part. 
               So once you've established the scope, given that
     scope, we go to the next level and looking at the results
     that we are trying to use in the decision making process
     defining what those -- what are the results that we want to
     get out of this scope of a PRA such things as a core damage
     frequency; large early release; identifying what our
     dominant accident sequence is; having an understanding of
     these.  So once you have laid out what are these results
     that you are trying to get out then to specify for the PRA
     what would be those elements that you need and then what
     would be the characteristics and attributes of those
               So this is the kind of level of detail.  We gave
     you some examples here of what we are going to be getting
     into. Where we will lay out all the elements and for each of
     those elements what are the characteristics.
               MR. POWERS: Let me ask you a question, and maybe
     it is just poor understanding on my part.  Come along and
     you say, our initiating events and it says, "It has to be a
     thorough identification of the initiating events." I presume
     that's what you mean.  And, I think it is pretty clear that
     none of us could make a thorough identification of the
     initiating events, or said more fairly, that if you came in
     with a listing of initiating events, I could always define
     an initiating event that you had not included in your list.  
               MS. DROVIN: Okay.
               MR. POWERS: And so it wouldn't be thorough. There
     must be a different definition of thorough here.
               MS. DROVIN: Again, I am not trying to say that
     this is what you need for every application. We are just
     laying out for a PRA given that scope, given that you want
     to produce a core damage frequency and you want to produce,
     you know, what your dominant accident sequences are, I mean,
     I just gave you some examples of the results, these are the
     characteristics and attributes that you would want for these
               MR. BONACA: I am having trouble with this in terms
     of quality.
               MR. POWERS: So what you are saying really is not
     thorough but inadequate characterization of the initiating
               MS. DROVIN: Probably a better choice of words.  
               MR. POWERS: Yeah.
               MS. DROVIN: So then when, for example, when we go
     to review the certification process or we go to review the
     ASME standard we would be looking at did they achieve this;
     does the standard, when we look at the requirements that are
     in the standard will it give us an adequate identification
     and characterization of the initiators.
               MR. POWERS: Suppose I come into you with my PRA
     and I say, "Look, I can't get a best estimate analysis code
     through Graham Wallis' committee.  He doesn't like anything
     I produce.  So all I did was come in with bounding
     conservative estimates on the success criteria."  I know I'm
     conservative on these things, they're not best estimate.  I
     mean, is there anything wrong with that?  He's penalizing
     himself.  Didn't have to be best estimate.
               MR. CUNNINGHAM: It can be because depending on the
     application what is conservative and bounding in one
     application may not be in other application.
               MR. POWERS: He has been very careful. He is a very
     careful guy. I mean he's smart enough to figure out what is
     conservative and what is not conservative on the outcomes.
               MR. CUNNINGHAM: He's a very bright person if he
     can do that. 
               MR. POWERS: He's not dumb. He knows he can't get
     things through Graham.
               MR. BARRETT: But if it materially effects the base
     line core damage frequency and lower frequency, it could put
     him outside of the acceptable ranges in REGI 1.174.  So at
     some point that licensee is going to end up of putting
     himself out of the range where we could approve anything.
               MR. POWERS:  Might want to come in if he done
     that, I suppose.  I mean --
               MR. APOSTOLAKIS:  Yes, bounding on our leases
     would probably play a role in some place here (inaudible).
               MR. PARRY:  I think part of the answer to that is
     recognizing that it is a bounding analysis and it comes into
     deciding how you cope with that uncertainty in the decision
     making.  I mean we can't say it as a general rule but I
     think that is where you would have to address these issues. 
     I mean in principle there is nothing wrong with it, but as
     long as you recognize what it is and what it is doing to the
     rest of your decision.  
               As Mark said what it could do is it could obscure
     some other things by raising --
               MR. POWERS: Very often true.
               MR. PARRY: -- raising certain frequencies of
     sequences that, you know, obscure others.
               MR. SEALE: More than that if it is a bounding
     calculation, you have given up the capability in your PRA to
     make a value judgment between --
               Mr. SHACK: Discrimination.
               MR. SEALE:  -- two alternative ways of doing
     things in terms of their risk consequences.
               MR. BARRETT: Exactly.
               MR. SEALE: Which is the problem we have had from
     the beginning.
               MR. APOSTOLAKIS: This slide does not say anything
     about uncertainty or not.  Is that some where else?
               MS. DROVIN: What I was saying its buried in here
     in the sense that we haven't -- this table here is about
     three or four pages long.
               MR. APOSTOLAKIS: Oh, you are just showing part of
               MS. DROVIN: I'm sorry, I should have pulled out
     the one that showed the uncertainty analysis.
               MR. APOSTOLAKIS: Okay.  Now --
               MS. DROVIN: I am just showing you some examples
               MR. APOSTOLAKIS: Yeah, but all the examples really
     refer to the construction of the (inaudible) sequences. That
     is why I was wondering. You are talking about adequate
     identification of initiators put in the hardware but I --
               MS. DROVIN: But all of the elements for --
               MR. APOSTOLAKIS: I think it is time that we --
               MS. DROVIN: If I go back here --
               MR. APOSTOLAKIS: No. I believe you.  
               MS. DROVIN: I mean we have elements that cover all
     of this.
               MR. APOSTOLAKIS: I believe you, Mary.  
               MS. DROVIN: You will see.
               MR. APOSTOLAKIS: I want to make another point
               MS. DROVIN: Okay.
               MR. APOSTOLAKIS:  That it seems to me that the
     uncertainty analysis that most PRA do, on federal rates and
     things like that, is really the easy part. The most
     difficult one is the modulate certainty issue.
               MS. DROVIN: Absolutely.
                         MR. APOSTOLAKIS: And maybe it is time that we
               emphasizing that. And at the beginning there will be some, you
     know, crude approaches perhaps, qualitative waving your arms
     and so on, but I think it is time we started emphasizing
     this that unless, in fact, coming back to the area of
     discussion, you know, can you really do without uncertainty
     analysis; yes.  Now what is it going to opposite the order
     ranking of the accident sequences; not a different value of
     the failure rate.  It is a model thing.  If you have missed
     something; if you have mismodeled something.  So is it a
     word like mismodeled?
               MR. POWERS: If there isn't there ought to be one.
               MR. APOSTOLAKIS: If there isn't there should be
               MS. DROVIN: One of the elements that we have,
     George --
               MR. APOSTOLAKIS: But I really think we ought to
     start emphasizing that. Recognizing that, you know, the
     methods, right now to handle it may be are not the best they
     need some proven. But we really have to do this.
               MS. DROVIN: I agree.  When you see the full
     document what you will see is one element that we call
     interpretation of results. And it get into what you do with
     the uncertainties.
               MR. APOSTOLAKIS: Good. So put it up front.
               MR. PARRY: Can I come back to this quality thing.
     I am still struggling with quality. Because it seems to me
     you can have all these list of things you have in these
     slides here, and then if I -- let me give an example, I only
     think in terms of examples.  If I'm thinking of say the
     quality of an automobile, there is brown A and there is
     Brown B, not to mention Rolls Royce and Ford and all those
     sort of things.  And they all have steering wheels; they all
     have wheels; they all have brakes. They all have these
     things all these things you listed here all PRAs have. What
     is it that makes one better quality than another?
               MS. DROVIN: Okay, it is not our intent to write in
     essence a standard. What we are trying to do here is at a
     high level put the frame work down and we were going to rely
     on either the standard or the certification to come in and
     tell us how have they done these things.  The detail should
     be there. We are using -- 
               DR. WALLIS: But how do you judge quality if your
     quality -- that's the thing -- At the very beginning the
     question was asked, "how do you define quality." I still
     don't see it.
               MR. APOSTOLAKIS: I think you would go a long way
     towards answering that question if you selected a few PRAs
     or IPEs from your wonderful report covering a spectrum of
     quality as it was judged at that time and go through this
     process and say, "Look, this is what we decide that this
     particular PRA or in this particular issue they did the
     whole job."  Because then you will start answering Dr.
     Wallis' --
               DR. WALLIS: And then these sorts of things answer
     the questions.
               MR. APOSTOLAKIS: This is too high level.
               MS. DROVIN: And it is meant to be high level.
               MR. APOSTOLAKIS: No, I understand. But I think
     giving a few case -- like Rich did earlier with risk
     conforming, risk conforming situations. I think you had some
     good examples there for human liability, for examples, "boy,
     these guys really did a lossy job." If you can tell us why
     you judged that and take out the criteria you used and put
     them in here I think that would go a long way towards
     answering these questions.
               And then, "the other guy did an excellent job,"
     well, why?
               Mr. POWER: If I could just parathentically say
     when you look at the NEI 0002 document, you're going to find
     high level questions like this analogous to this. But you
     are also going to see sub-tier criteria of things that get
     down deeper and ask more detailed questions.  If you are
     reviewing an application, as I said earlier, the first
     decision you have to make is how deeply are you going to go
     in a particular area in the review of the particular
               MR. APOSTOLAKIS: Just a minute.
               MR. Power:  -- of the type that Mary has here. And
     that is going to depend on what you see also.
               MR. PARRY: I think quality maybe defined in terms
     of what this garry will do, not what is in it.  That goes
     back to the very beginning.
               MR. APOSTOLAKIS: To the decision, yeah.
               MS. DROVIN: And we're going to get to that. But I
     am saying if you just had the PRA and you're trying to judge
     it based on this thing here and let's use the ASME standard
     as an example.  And if I go in and I'm looking at the
     initiating event and that there is no requirements in there
     that tell me how they do an adequate identification and
     characterization of initiators, they are going to flunk
               MR. APOSTOLAKIS:  Right.  At this level, yes.
               MS. DROVIN: Because I need that --
               MR. APOSTOLAKIS:  You're right.
               MS. DROVIN: -- to get a technically acceptable
     PRA.  So, I am going to be looking for requirements and all
     those requirements of sufficient detail to assure that.
               Mr. APOSTOLAKIS:  I guess Dr. Wallis' question,
     some of mine go beyond this. You are absolutely right.  
               Now this is page 15 of 19 and it is 4:05, for
     twenty-five minutes.
               MS. DROVIN: We can do it. Trust me.
               MR. POWERS:  The question is whether we can do it,
               MS. DROVIN:  I'll talk about us here.
               But the next slides, you will see kind of a
     similar format.  Once we have established, you know, we say
     we have this scope that we have established and these
     characteristics and attributes that we are going to look at,
     how do you go about confirming that you've achieved those? 
     One way is through appear/review process. You can use that
     to confirm your technical acceptability.  So now if someone
     chooses to go that route, so when we look at the NEI
     certification there will be certain attributes just to that
     process that we would be looking for such that that process
     is an adequate mechanism for insuring your technical.  
               So again, here are some examples where the
     elements we would be looking for better talked about the
     team qualifications; the peer review process; the
     documentation; and then for each of those laying out what we
     would think would be the characteristics and --
               MR. APOSTOLAKIS: You know team qualification is
     something that I think is utterly misleading.
               MS. DROVIN:  I'm sorry.
               MR. APOSTOLAKIS:  Usually, the team qualification,
     usually it is in terms of how many years you've been in the
     business, right.  You could be in the business -- you could
     be for twenty-years and be consistently wrong.
               MS. DROVIN: I don't think (inaudible) is.
               MR. APOSTOLAKIS: I mean it's not a problem.  I
     think the process it really what matters in qualifications. 
     Conflicts of interest, I mean, yeah, right.
               MR. PARRY: That may exclude anybody that knows
     anything valuable.
               MR. APOSTOLAKIS:  By the way you don't have
     twenty-five minutes because Mr. Bradley will have a few
               MS. DROVIN: Okay.
               MR. APOSTOLAKIS: Okay, we understand where you are
     coming from.
               MS. DROVIN: The next one gets into the heart, in
     some sense, because we do recognize that not every
     application needs to meet that scope or all of those
     elements and attributes. So how do you go about deciding
     what needs to be in scope; what needs to be out of scope
     such that you have technically acceptable PRA and you can
     have confidence in the results you are going to be using to
     generate your risk insights.  
               MR. SEALE: So you're going to housesit us?
               MS. DROVIN: So there is some, a decision process,
     that you can go through.  We've tried to layout what we
     think are the necessary elements of this process and then
     for each of the elements what would be the characteristics
     and attributes for each element.
               Then the last piece is getting to the expert
     panel. The expert panel review has a potential to be used in
     two ways. First taking your results to integrate them into
     the decision process, integrate your risk insights.  The
     other thing is that when you look at your PRA and when you
     are out of scope or say you're in scope and you haven't done
     your arithmetic correctly, or you have some difference or
     some deficiency and you are going to use your extra panel to
     make up for that.
               MR. APOSTOLAKIS:  You know we are doing a lot of
     that, and I don't like it.
               MS. DROVIN: Excuse me.
               MR. APOSTOLAKIS: Every time a method is found to
     have problems we say, " Why don't the expert finally take
     care of that?"  So I would be very cautious --
               MS. DROVIN: Oh, I agree.
               MR. APOSTOLAKIS:  -- using that kind of argument. 
     I mean, if the importance measures have a problem why don't
     the expert find out what to do about it. We miss something,
     ah, let the expert find it.
               MR. SEALE: By the time you get the well developed
     PRA, you may even have some expert panel members that are
     truly qualified.
               Mr. Shack: Well, you might.
               MR. SEALE: And their related process. They are an
     inverse process.
               MS. DROVIN: So again, given that those are the two
     ways that an expert panel can be used, we are trying to
     identify what would be the necessary elements of an expert
     panel considering those two applications and then what would
     be, again, the characteristics and attributes, and again,
     these are just examples this is not complete just to give
     you a flavor of where we are going.  And those are all the
     pieces that fill the (inaudible) 
               MR. APOSTOLAKIS: I think it would help you a lot
     and us for sure, if you actually -- if you would set an
     example from the ideas that you are very familiar with.  Go
     through them; apply your criteria here and say, "Well, gee,
     my decision at the time was that this was a poor analysis." 
     "Can I conclude that by strictly applying what I have here
     or do I have to expand this?"  I think you are going to
     learn a hell of a lot by doing that, and then you are also
     going to convince others.  Because I remember there were
     some outlines, right?
               MS. DROVIN: Oh, yes. We can walk you through some
               MR. APOSTOLAKIS: You came in here you gave us
     reasons and so on.  Are these judgments, you used at the
     time, do these judgments flow naturally from what you have
     here or do you have to add something; and then you will be
     able to answer Dr. Wallis' concerns, I think, much much
     better. But also you will have to select some good ones.
               MR. CUNNINGHAM: Yes, that's right. You'd have to
     pick some --
               MR. APOSTOLAKIS: Show that, you know, yeah, we
     decided that this was a very good one because this and that.
               MR. CUNNINGHAM: That's right.
               MR. APOSTOLAKIS: Because the problem is the
     (inaudible) presentation not the high level stuff.  So I
     would like to see that and it shouldn't be hard for you to
     do especially, Mary.
               MS. DROVIN: Yes, we've gone through several so we
     can do that.
               MR. APOSTOLAKIS: Okay.
               MS. DROVIN: Our last slide is (inaudible).
               MR. APOSTOLAKIS: It's so sketch.
               MR. SEALE: It's sketch.
               MR. APOSTOLAKIS: I can't believe that you are
     talking about the weeks, usually here it is years.
               MR. CUNNINGHAM:  Well, sometimes you have
     schedules opposed upon you. At any rate, the bottom line on
     this is that we got two or three items facing us right now
     that are all related to this issue of PRA quality, if you
     will. How are we going to review the ASME; how we're going
     to review ANS; how are we going to review the NE document,
     any "I" documents in the context of option two.
               What you heard about is a brief description of how
     we are going to take that on in a more integral way. Our
     goal is in the next couple of weeks to put together a
     commission paper that lays this out.  We are going to be
     discussing with the PRE Steering Committee in the middle of
     June. The idea is to have the paper to the DDO on June 27th.
               MR. APOSTOLAKIS: What is RILP, R-I-L-P?
               MR. CUNNINGHAM: Risk Informed Licensing Panel.
     That is a panel of, basically, division directors but some
     others. Tom is the vice-chair, Gary Hollihand, is the
     chairman. It is used to air issues among the various
     organizations in NRA on risk informed issues, basically.
               MR. APOSTOLAKIS: So they are risked informed in
     the since that they understand PRE?
               MR. CUNNINGHAM: They bring together all of the
     disciplines that are (inaudible), yes. Believers and
     skeptics all brought together to hammer out the issues.
               MR. APOSTOLAKIS: Are you asking us to write
               MR. CUNNINGHAM:  No, we are not asking you to
     write a letter at this point.  That you have nothing, as you
     said at the beginning --
               MR. APOSTOLAKIS: That's right.
               MR. CUNNINGHAM: We have nothing -- we've provided
     you nothing so it wouldn't be fair to ask to write a letter.
               MR. APOSTOLAKIS: Would you like us to write one in
     July; or you really don't care?
               Mr. King: Yes, we would like you to write
     something in July.  This is Tom King.
               MR. APOSTOLAKIS: Oh, you would?
               Mr. King: Yes.
               MR. CUNNINGHAM: Yes.  
               Mr. King: It is unfortunate do to the schedule we
     didn't have time to get you something in advance.
               MR. APOSTOLAKIS: That's all right.
               Mr. King: But, you know, consider this in effect
     what we are writing is a high level standard review plan
     that the staff is going to use to assess the various things
     that are on our plate that deal with PRE quality. And I
     think when you --
               MR. APOSTOLAKIS: That is all we will have to
     review then (inaudible) schedule for (inaudible).
               Mr. King: I think a letter in July would be very
               MR. APOSTOLAKIS: Anything else, lady and
               Mr. King:  Thank you for your time.
               MR. APOSTOLAKIS:  Well, maybe we can give Mr.
     Bradley a few minutes and thank you very much. Very cordial
     as usual.
               Mr. King: Thank you.
                    BIFF BRADLEY
               MR. APOSTOLAKIS: Welcome back, Mr. Bradley,
               MR. BRADLEY: Back again. I am Biff Bradley. I am
     with the Indiana staff in their Regulatory Reform area.  I
     think that I have more time than I need.  I don't have a
               Mr APOSTOLAKIS: You don't have to use all of it.
               MR. BRADLEY: Good. Well, you know bereavety is the
     sole of wit. I concur with, I think, everything I heard the
     staff just say and I think, you know, the philosophy that
     was laid out, there is no fundamental disagreement with
               Mr. KRESS: Is it a lot like the certification
     process, the NEI certification process? What they laid out?
               MR. BRADLEY: Well, I think what they laid out is
     one, it has to be -- as an acknowledgment there will have to
     be some NRC review for any application and I view the
     standard or certification process as a means to streamline
     and expedite that review and whichever one you use.  
               I also concur that it is like a, you know, trying
     to define truth or duty -- trying to define quality in the
     abstract of -- it is not a -- I think has created a lot of
     problems. In my view, quality has to be defined in the
     contents to the application. Maybe suitability is a better
     word to be using.  And I think, you know, for option two, as
     we move along and we understand what the application is and
     what is involved, you know, we came to the conclusion that
     we could use this certification process for that particular
     application and that is what we submitted to NRC with
     respect to review for that purpose.  
               So, we look forward to working with the staff and
     working through the issues with the certification process. I
     think we've, you know, struggled a lot with the ASME
     standard and it has been in the context of trying to write a
     standard that would envelope all the different applications
     that are going on and that is a very difficult thing to do,
     and it is much easier to address a specific application and
     come to grips of what you need to do that.
               The one thing I would mention, there was a fair
     discussion, not a discussion, of IPEs. I think the industry,
     we are going to have to take some initiative to update the
     data bank that is out there with regard to what has been
     done.  IPEs are becoming, you know, extremely obsolete.
               MR. APOSTOLAKIS: Becoming, Biff. Becoming.
               MR. BRADLEY: Well, they have and we moved way
     beyond that.  But I think it tends to be, that what is sort
     of in the public record, you know, and that's what -- we
     need to establish a new record that gets us --
               MR. POWERS:  Well, the IPEs are the sole virtue
     and up to datedness compare the IP tripilees.
               MR. BRADLEY: Yeah.
               MR. APOSTOLAKIS: No. But the reason that he
     brought up the IPEs is not to use them in any particular
     way, but to actually show what good or bad is in that
     context of that particular analysis for plan A.  I mean we
     are not going to sing loud to anybody.
               MR. BRADLEY: Right. So, you know, generally, I
     look forward to seeing the commission paper and we are, you
     know, facing a lot of challenges in regulatory reform and
     despite the amount of publicity that this PRA quality issue
     gets, I think there are other challenges in regulatory
     reform that are going to be more difficult in having to do
     with how you reform the regulatory treatment in light of
     these insights and how you measure the impact of that.  And
     so, I view the categorization of something we can
     successfully accomplish.
               I think the harder part is going to be dealing
     with non-internal events risk because generally you are
     going to be using some qualitative, or semi-quantitative
     methods there.  If it is something we are going to do in the
     next, you know, reasonable five years or so. 
               So, you know, please to hear what the staff had to
     say and I think the industry concurs with the approach that
     was laid out.
               MR. APOSTOLAKIS: I think you would help the whole
     thing along if you and the staff agree to drop the word
     "quality". Supergroup, perhaps, is a good word. Quality is
     really bad.
               MR. POWERS: Unfortunately, it is the commission
     that is the one that has used the word.
               MR. APOSTOLAKIS: Sometimes the commission uses
     staff's words. I mean, if the staff comes back and it says
     this is the reason.  I think the commission will be willing
     to listen.  You always want quality.
               MR. BRADLEY: Right.
               MR. APOSTOLAKIS: Quality is always there.
               MR. POWERS: Well, I will -- many of you have not
     enjoyed the things that Dr. KRESS and I enjoyed during our
     careers at the National Laboratory where we learned that
     quality doesn't always mean what you think the dictionary
     says quality is.
               MR. APOSTOLAKIS: [Laughter].
               MR. POWERS: We learned definitions like,
     satisfying requirements of the customer and any number of
     other things that have --
               MR. APOSTOLAKIS: To avoid fault.
               MR. POWERS:  -- a unique definition to the word
     quality.  So --
               MR. APOSTOLAKIS: You satisfies
               DR. SEALE:  Whimsy is the characteristic of many
     of these words.
               DR. POWERS: That is why one of the reasons I asked
     for the definition of quality at the beginning.
               DR. SEALE: Right.
               MR. POWERS: Unfortunately, I had been brainwashed
     to learn --
               MR. SEALE: MR. BRADLEY --
               MR. POWERS: -- to give up my knowledge of the
     English language and adopt a bureaucratic knowledge of the
     word quality.
               MR. APOSTOLAKIS: Dr. Seale.
               DR. SEALE: You have had input to this process,
     clearly, in much the same way the NRC staff has in working
     with the ASME and also, I guess, the ANS people who are
     working on the other two parts of it. And presumably, but
     presumably, in addition to those inputs as you have gone
     along, you are going to be doing a similar review of the
     final document to, if you will, paint your imprint on this
     overall standard in much the same way that the NRC staff has
     done it.  
               Are you going to steal their outline and follow it
     when you go home, or if you got another outline of how you
     are going to go -- through process you are going to go
     through in reviewing the ASME standard?
               MR. BRADLEY: If I understand your question
     correctly, I think much of that has already transpired in
     the writing of the standard. There is a history going back a
     couple of years and at various times I think the staff has,
     you know, weighed in with their position and then the
     industry has weighed in. I think our general sense has been
     that a standard should reflect to the degree possible and
     appropriate existing practice. And we at the existing
     practice in this case is the peer review process that has
     been developed and it has been applied. So our efforts as an
     industry has been to make the standard comport with that
     process to the degree we can and I think it has come a long
     way.  We are looking at Rev. 12 now, and it will be out for
     public comment.  And our view, I think a success in this is
     if we have a standard and ASME standard that is reasonably
     consistent with our process of (inaudible).
               MR. SEALE: Thank you. That is a very fair
     characterization of your position. I appreciate it.
               MR. APOSTOLAKIS: Okay, anything else?  Any other
               Thank you, Biff.
               MR. BRADLEY: Sure.
               MR. APOSTOLAKIS: Back to you, Mr. Chairman
               MR. POWERS: Thank you very much.
               At this point we can dispense with the
               [Whereupon, the recorded portion of the meeting
     was recessed, to reconvene at 8:30 a.m., Thursday, June 8,

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