Meeting: Reactor Fuels - April 4, 2001


                Official Transcript of Proceedings


Title:                    Advisory Committee on Reactor Safeguards
                               Reactor Fuels Subcommittee

Docket Number:  (not applicable)

Location:                 Rockville, Maryland

Date:                     Wednesday, April 4, 2001

Work Order No.: NRC-146                               Pages 1-242

                   NEAL R. GROSS AND CO., INC.
                 Court Reporters and Transcribers
                  1323 Rhode Island Avenue, N.W.
                     Washington, D.C.  20005
                          (202) 234-4433                         UNITED STATES OF AMERICA
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                        REACTOR FUELS SUBCOMMITTEE
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                                + + + + + 
                               APRIL 4, 2001
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                            ROCKVILLE, MARYLAND
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                       The Subcommittee met at 8:30 a.m., at the
           Nuclear Regulatory Commission, Room T2B3, Two White
           Fling North, 11545 Rockville Pike, Rockville,
           Maryland, Dana A. Powers, Chairman, presiding.
                       DANA A. POWERS, Chairman
                       GEORGE E. APOSTOLAKIS, Member
                       MARIO V. BONACA, Member
                       THOMAS S. KRESS, Member
                       WILLIAM J. SHACK, Member
                       ROBERT E. UHRIG, Member
           PRESENT (Continued):
                       AUGUST W. CRONENBERG, ACRS Fellow
                       MEDHAT EL-ZEFTAWY
           ALSO PRESENT:
                       MICHAEL ALDRICH
                       SUDHAMAY BASU
                       EDWARD BURNS
                       RYAN T. COLES
                       MARGARET CHATTERTON
                       SKIP COPP
                       RALPH CARUSO
                       DAVID DIAMOND
                       GARRY GARNER
                       RICH JANATI
                       STEVE LA VIE
                       RICHARD LEE
                       EDWIN LYMAN
                       BOB MARTIN
                       LARRY OTT
                       JACK ROSENTHAL
                       HAROLD SCOTT
                       UNDINE SHOOP
                         AGENDA ITEM                       PAGE
           Introduction . . . . . . . . . . . . . . . . . . . 4
           Research Activities on High Burnup PIRT  . . . . . 5
           Framatome Testing and Assessment of LOCA
                 Ductility of M5 Cladding . . . . . . . . . .77
           Westinghouse Testing and Assessment of LOCA  
                 Ductility of ZIRLO Cladding  . . . . . . . 116
           Summary of OECD Topical Meeting on LOCA
                 Fuel Safety Criteria . . . . . . . . . . . 137
           Recent Operational Issues and Experience with
                 High Burnup Fuel . . . . . . . . . . . . . 158
           Research Activities on MOX Fuel  . . . . . . . . 191
           Presentation by Dr. Edwin S. Lyman . . . . . . . 209
                                                    (8:31 a.m.)
                       CHAIRMAN POWERS:  The meeting will come to
                       This is a meeting of the ACRS Subcommittee
           on Reactor Fuels.
                       I'm Dana Powers, Chairman of the
                       ACRS members in attendance are George
           Apostolakis, Thomas Kress, William Shack, Mario
           Bonaca, Robert Uhrig.  We also have the ACRS Fellow,
           Dr. Gus Cronenberg, attending this meeting.
                       The purpose of the meeting is to discuss
           the safety issues associated with the use of high
           burn-up and mixed oxide fuels.  The Subcommittee will
           gather information, analyze relevant issues and facts,
           and formulate proposed positions and actions as
           appropriate for deliberation by the full Committee.
                       Medhat El-Zeftawy is the cognizant ACRS
           staff engineer for this meeting.
                       The rules for participation in today's
           meeting have been announced as part of the notice of
           this meeting previously published in the Federal
           Register on March 14th, 2001.
                       A transcript of the meeting is being kept,
           and it will be made available as stated in the Federal
           Register notice.
                       It is requested that speakers first
           identify themselves and speak with sufficient clarity
           and volume so they can be readily heard.
                       We have receive done request for time to
           make oral statement from a representative of the
           Nuclear Control Institute regarding today's meetings.
                       Do members have any other comments they'd
           like to make before we enter into today's rather
           interesting discussions?
                       (No response.)
                       CHAIRMAN POWERS:  Seeing none of those,
           then I think we'll just proceed directly ahead, and
           I'll call upon Dr. Ralph Meyer to begin us in this
           discussion of some of the most interesting research
           going on in the Agency.
                       PARTICIPANT:  This is when we figure out
           if Ralph is a theoretician or an experimentalist.
                       CHAIRMAN POWERS:  Know the answer?  I know
           the answer.  Dr. Meyer can organize both research and
           analysis to produce useful outcomes for the regulatory
           process, right, Ralph?
                       DR. MEYER:  Couldn't have said it better.
                       DR. MEYER:  Okay.  I have a lot more
           material later for the second presentation, which is
           a summary of a meeting that was held recently on the
           subject of the embrittlement criteria.  So I'm going
           to try and stick with the time period that's been
           provided here, and that means that I have a couple of
           slides that I just want to throw on for background so
           that they'll be in your package, and I didn't mean to
           dwell on every single slide in the package.
                       I'm going to spend most of the time
           talking about the PIRTs and trying to say what we
           learned from them and what we're going to do about it. 
           If there's a little time left over, then I can talk
           about the status of some of the various research
                       CHAIRMAN POWERS:  Okay.  That would be
           useful.  Because this is a Subcommittee meeting, I'm
           pretty liberal with the time allotments because
           there's no other opportunity we have to discuss
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  So I'll hold the
           schedule roughly correct, but if you have things that
           you think we ought to hear, feel free to tell us.
                       DR. MEYER:  Okay.  The first slide is just
           some background information on the alloys that we'll
           be talking about.  Zircaloy has ten in it.  I think
           everybody knows that.  Low tin Zirc is tin with a
           concentration in the range of 1.2 to 1.4 percent. 
           ZIRLO is like low tin Zircaloy.  Add a percent niobium
           and M5 is zirconium and one percent niobium, more or
                       We will be referring to these off and on
           throughout the day.
                       Also I want to point out some of the
           criteria that we are looking at.  We are looking at
           criteria for postulated accidents.  These are the
           things that were identified in the agency program plan
           a couple of years ago, and just in general, we have
           criteria on fuel damage to make sure that the damage
           is limited and that we don't get uncoolable core
                       Specifically for over power events, we
           have a criterion of 280 calories per gram fuel
           enthalpy as a limit for a rod ejection accident, which
           is the big over power event in the PWR that's
                       We have embrittlement criteria in the
           regulations for the loss of coolant accident.  We'll
           talk about those a lot today.
                       There are similar limits on fuel damage
           during dry storage, and these are related to creep
           deformation and also to peak temperature during the
           early stages of dry storage.
                       This work on the fuel damage limits for
           dry storage is also going on in our program.  I don't
           plan to talk about that today unless I get questions.
                       CHAIRMAN POWERS:  I think I would try to
           keep the two separate, but it doesn't hurt to
           parenthetically note if one result relates to the
           storage issues.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  Yeah, parenthetically
           noting where there's overlap is fine, but I don't
           think I want to go into the storage stuff in great
           detail right now.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  Stay with the real
                       DR. MEYER:  Okay.  The safety criteria
           that we used for all developed for fresh or low burnup
           Zircaloy clad fuel rods.  We believe for many years
           that low burnup also provided the limiting conditions,
           but with the movement to the higher burnup fuels and
           the large concentrations of burnable poisons, you can
           now see peak powers occurring later, not at the
           beginning of life, but as late as end of second cycle.
                       So we have to take a look at the criteria
           at higher burnups, and of course, we started doing
           this in a general way some time ago.
                       The criteria that apply to these
           situations were also developed for Zircaloy cladding,
           and in the beginning at least there was an assumption
           which seemed like a good assumption, that if the
           advanced alloys improve the performance during normal
           operation, that it would do so during the accidents as
           well, and in some cases that may be true.  In some
           cases it might not be true.
                       But in any event, we are now looking at
           high burnups and other cladding alloys to try and
           confirm these assumptions or find other results if
           that's what happens.
                       DR. CRONENBERG:  Ralph, why did you think
           that early ripe (phonetic) conditions were more
           limiting?  You didn't have much fission product
           buildup.  You didn't have much corrosion,
           embrittlement.  So what was the original thoughts on
                       DR. MEYER:  Yeah.  Usually the big actor
           is the power, is the linear heat rating of the fuel
           rod.  In a loss of coolant accident, both the stored
           energy and the decay heat from short-lived species is
           proportional to the power, and that often dominates
           other things.
                       We've been looking for a very long time at
           things like rod pressure and gap opening at high
           burnup during normal operation because they also have
           a fairly significant impact on the conditions during
           a loss of coolant accident.  The gap conductants is a
           big player.
                       DR. CRONENBERG:  I'm surprised at that
           view because water side corrosion was an early -- you
           know, a phenomenon identified early with Zircaloy,
           when new corrosion was a problem.
                       DR. MEYER:  It's just a historical fact.
                       DR. CRONENBERG:  Okay.
                       DR. MEYER:  I mean, we're not being
           governed by this point of view at the present time.
                       DR. CRONENBERG:  Yeah.
                       DR. MEYER:  But this is sort of how we got
                       Now, the status of where we are right now
           is that we have burnups approved to 62 gigawatt days
           per ton.  This is average for the peak rod in the
           core.  In Europe they tend to report their license
           limits in terms of average for the peak assembly,
           which is a lower number by about ten percent.  So you
           have to keep that in mind.  We are not that far ahead
           of the rest of the work in our burnup approvals.
                       And this applies to the three major alloys
           that are in use at the present time.  Specific
           questions now have been raised about these criteria
           for postulated accidents.  A long time ago we learned
           from both the Cabri program in France and the NSRR
           program in Japan that the 280 calorie per gram number
           that we're using for the reactivity accidents is
           probably not valid at high burnups.
                       Oh, four or five years ago we raised
           question about the effect of corrosion during normal
           operation, the oxide buildup during normal operation,
           and how that should be added into the corrosion during
           a high temperature transient in LOCA in order to
           compare with the 17 percent criteria and whether there
           would be some other effects.
                       And so we've recognized some -- and more
           recently, the questions that will be addressed heavily
           in this meeting by the later presenters and then in
           the summary of the meeting that I'll be describing
           about the possible effects of niobium on the
           embrittlement criteria for loss of coolant accident.
                       So there are now some -- we had general
           questions about whether we should be looking at the
           validity of these criteria for high burnups and other
           alloys.  Now we have some specific questions, and
           we're just continuing a broad approach to this whole
                       We have in our agency program plan of a
           couple years ago agreed that we would not ask the
           industry to do the confirmatory work for the currently
           approved burnup range, that we would do that
           ourselves.  And that's the big mission in the research
                       So we are specifically addressing all of
           these criteria, effects of burnup and alloys for
           burnups up to 62 gigawatt days per ton.
                       The industry has been told that they will
           have to do all of those things for the burn-up
           extensions above that.
                       In order to try and improve our progress
           on the work with the NRC's confirmatory obligation, we
           organized these PIRT panel meetings which I'm going to
           talk about here. 
                       PIRT is a phenomenon identification and
           ranking table.  You build tables of phenomena that
           occur during the events that you're studying, and you
           try and learn something about that by discussing the
           importance in each of those, of each of those
                       DR. KRESS:  Ralph, when you talk about a
           burnup limit, like the 62 --
                       DR. MEYER:  Yeah.
                       DR. KRESS:  -- that's for the limiting
           high power assembly?
                       DR. MEYER:  That's average burnup for the
           peak rod.
                       DR. KRESS:  For the peak rod?
                       DR. MEYER:  That's a peak rod, yeah.
                       DR. KRESS:  Now, what does that translate
           into for the average burnup of the whole core?
                       DR. MEYER:  Well, it's a lot lower.
                       DR. KRESS:  Yeah, I would assume.
                       DR. MEYER:  You know, you go from the peak
           rod --
                       DR. KRESS:  The peak rod is like 1.4?
                       DR. MEYER:  Mitch Nissley from
           Westinghouse probably has an answer right on the tip
           of his tongue.
                       MR. NISSLEY:  These are very approximate.
                       Mitch Nissley from Westinghouse.
                       I would say at the beginning of the cycle
           a reasonable core average burnup would be in the order
           of 20,000 gigawatts or 20 gigawatt days per metric
           ton, and that by the end of the cycle they're probably
           in the low 30s.
                       DR. KRESS:  Okay.  That's --
                       MR. NISSLEY:  And that's for a fairly
           aggressive core design.
                       DR. KRESS:  Okay.  Thank you.
                       DR. MEYER:  Okay.  The dry storage issue,
           the dry storage situation is a little different.  The
           task had been proved for fuel burned up to 45 gigawatt
           days per ton, and we are able in our reactor oriented
           programs to look at the dry storage conditions.  So
           these are folded into one of the big programs that
           we're doing.
                       So we did three different PIRTs, which we
           refer to together as the high burnup PIRT.  One was on
           the rod ejection accident.  For a PIRT activity,
           you're supposed to assume a very specific sequence,
           and so in this case, we assumed that the rod ejection
           accident occurred in TMI-1 with high burnup fuel at
           hot zero power.
                       TMI-1 was chosen because it had been used
           for an international standard problem.  There were
           input decks.  We have done extensive analysis in our
           cooperative work with IPSN in France and Kurchatov in 
                       So we had a lot of analysis on TMI-1 rod
           ejection accident, and we chose that as the base case
           for that PIRT.
                       For the BWR power oscillations, we chose
           Lasalle-2, which had some oscillations and a lot of
           analysis.  So, again, there was an analytical base
           that we could build on, and again, we assumed high
           burnup fuel in that core.
                       When we came to the loss of coolant
           accident, however, we did not pick a specific plant. 
           We didn't even specify whether we were talking about
           a BWR or a PWR or a small break LOCA or a large break
                       We did, however, have discussions on each
           of those.  We had major presentations given to the
           PIRT panel members prior to their ranking activity on
           small break, large break and BWR and PWR.  So all of
           that information was given to the panel members, and
           in the end, we decided to just go with a generic loss
           of cooling accident with Zircaloy clad fuel at 62
           gigawatt days per ton.
                       Now, I think last year at this
           Subcommittee meeting we were already into the PIRTs,
           and so we had talked about them.  I don't go into a
           lot of detail.  We had about 25 fuel experts from all
           over the place.  The approximate sign is not because
           we can't count to 25, but because it varied from time
           to time, and we would tend to have a slightly
           different mix of people for the BWR events and the PWR
                       We held eight meetings, a total of 25 days
           of meetings.  This is really quite a large commitment
           of resources to this activity.  We prepared three
           NUREG reports, and I think most of you, if you have
           not seen the reports, you at least have had access to
           them.  They're quite large.  They are on the Web, and
           they're nearly finished.  We have final draft
           versions, which are out electronically to the PIRT
           panel members for final comment, and our hope is to
           publish them at the end of this month.
                       We also have a staff report which I wrote
           that tries to give our interpretations of what we
           learned and some suggestions about how we can move
           forward with that.  That is also written up as a draft
           report.  It's not on the Web in its final form.  We're
           trying to decide how to publish that at this time.
                       However, the three main components of that
           report are on the Web.  They were developed as we went
           through the PIRT process as little white papers, and
           they're on the Web, along with the PIRT reports.
                       CHAIRMAN POWERS:  Well, you've been
           through the PIRT exercise.  Would you do it again if
           you had a similar problem?
                       DR. MEYER:  Probably.  It's an imperfect
           process when you apply it to a mixed situation like
           this.  I think the PIRT process probably works best
           when you apply it to development of a computer code,
           like one of the large thermal hydraulics codes, and I
           believe that was the environment in which the
           technique was developed.
                       When you apply it to a more general
           subject, the we found that we had to be a little bit
           fast and loose with some of the concepts and a little
           bit creative in the way that we tried to put it
                       In fact, at these eight meetings that we
           held, the first three-day meeting was basically
           written off as one where we just floundered around and
           tried to figure out how to go forward, and we started
           over again with the rod ejection accident in the
           second meeting.
                       So there's a high cost to this because we
           had people from the industry, from overseas, from all
           over the place coming in largely at their own expense,
           and I don't know how many times you can generate
           enough interest and enthusiasm to do that.  
                       We are trying again with the source term. 
           It's an important subject, and probably we'll be able
           to generate the same kind of interest in the source
                       I'm not sure that we could do this every
           four or five years as a routine matter.
                       Also, I would say since we're on the
           subject of opinions, the result of a PIRT ranking by
           and large are boring.  I mean, you list a lot of
           phenomena and you rank each one as high, medium and
           low importance with regard to some outcome, and you
           usually get what you knew at the beginning.
                       So we got a lot of tabulated results that
           just summarized what we already knew.  The thing about
           it was that there were for some of us in any event,
           there were some surprises and some light bulbs that
           went off, and this just would not have happened
           without the broad discussion with all of these people
           in the room.
                       And I think that's what made it
           worthwhile.  It also makes it risk because if a light
           bulb doesn't go off, then maybe you've spent a lot of
           money and didn't get anywhere.
                       So let me now try and go through these
           three PIRTs very quickly.  Just for calibration
           purposes, the rod ejection accident occurs when you
           postulate to the control rod drive mechanism, brakes,
           and is ejected from the vessel by the pressure
                       You get a prompt critical power pulse.  In
           a power reactor the width of the pulse at half maximum
           is about 30 milliseconds.  You get the cladding
           temperature rise that lags this a little bit.  You get
           a strong negative Doppler feedback due to the power
           pulse, which basically shuts it down.
                       DR. KRESS:  Now, is this local or --
                       DR. MEYER:  It is local.  It's localized
           to several neighbors around the ejected rod, and so it
           is not a core-wide event.
                       DR. KRESS:  Not  core-wide event.
                       DR. MEYER:  Right.
                       DR. APOSTOLAKIS:  Which one is regulatory
           guide to 177?
                       DR. MEYER:  One, seven, seven is for the
           rod ejection accident.  It's -- I don't know the exact
           title, but it's the methods and assumptions for
           analyzing a PWR rod ejection accident, specifically
           for that event.
                       And it has the assumption of 280 calories
           per gram in that --
                       DR. APOSTOLAKIS:  I'm confused.  Don't we
           have a risk informed guidance on 177 as well?
                       PARTICIPANT:  Seventy-four.
                       DR. APOSTOLAKIS:  Five, six, seven?
                       PARTICIPANT:  Those are the same.
                       PARTICIPANT:  It's 117.
                       DR. APOSTOLAKIS:  Oh, 11?
                       PARTICIPANT:  This is an oldie.
                       DR. MEYER:  Oh, it's very old.  I think
           this was safety guide 77 in the prehistoric time.
                       DR. APOSTOLAKIS:  It's one.  But you said
           interesting things about PIRT, and for years now I've
           been hearing people talk about PIRT in awe.  What's so
           big deal about it?  Why are people so impressed by
           PIRT?  Was K used before?
                       DR. MEYER:  That's a fair question.  I
           think to some extent, I think there is a little over
           expectation.  I've felt this from the beginning and
           have tried to make the best of it, and I think we have
           come out pretty well on this one because we learned a
                       It is not much more than a little bit of
           organization in a big discussion of a lot of experts. 
           So it's a way of getting experts around to get their
           opinions in a more or less organized way.  That's what
           it turned out to be for us.
                       CHAIRMAN POWERS:  George, I would say that
           in this context and having attended one day of one of
           the PIRT discussions --
                       DR. MEYER:  I hope it wasn't the first
                       CHAIRMAN POWERS:  No, in fact, it was the
           second one, but I think this floundering that you
           encountered on the first one is typical even among the
           thermal hydruaulicists when they undertake a PIRT. 
           The first round is always a bunch of floundering
           because you're asking everybody to get on the same
           page at the same time, and that's difficult because
           they come in with different imperatives in which their
           expectations are.
                       But it seems to me that when you're
           struggling to understand how to approach a problem
           that is calling into question things that are as old
           as 1.77, and it's not a question of is it 280 calories
           or 220 calories or 100 calories.  Is the whole concept
           any good or not?
                       When you're struggling with that, you want
           to get the best people to look at it and say, yeah,
           you've thought about all of the things that are likely
           to be important.
                       Now, they can be flat wrong because they
           don't have a great deal of experience working in this
           regime, but you're confident that you've tapped into
           as much knowledge as you're likely to have in setting
           up and planning something.
                       Now, the idea is that you go on and you do
           some research and some experiments and things like
           that, and you're going to learn more about it, but at
           least you start off knowing what you ought to be
           looking for.
                       DR. APOSTOLAKIS:  And there is consensus
           at the end?  You said that there is a ranking of high,
           medium and low, and so on and so forth.  Are we at the
           end of this phenomenon?
                       DR. MEYER:  We had a very large panel,
           atypically large, and we're told by our panel
           organizer, Brent Boyack, who's done a lot of these,
           that typically with the panels on the order of six to
           eight people, that they do, indeed, reach consensus
           just naturally on these.
                       We did not, and we did not attempt to
           reach a consensus.  Instead we voted, and we recorded
           the votes and the rationales, and so you tend to get
           a distribution of answer, high, medium, and low, and
           often there's a sizable majority, and you can go and
           look and see what the reason was for that and why some
           other people didn't quite agree with it.
                       DR. APOSTOLAKIS:  That assumes, of course,
           that everybody's vote is equally important.
                       DR. MEYER:  Well, you know, we even
           addressed that.  We asked the PIRT panel members to
           vote only when they felt that they had a good basis
           for voting and that we didn't expect them to vote on
           every item because we had a range of subjects from
           analytical to experimental, and so there was some
           restraint on that.
                       DR. KRESS:  If you had a split vote, 16 --
                       DR. MEYER:  If you had a what?
                       DR. KRESS:  Sixteen of your members voted
           high and the rest of them voted it low.
                       DR. MEYER:  Yeah.
                       DR. KRESS:  Would that automatically make
           it high?  Is that the way you would have ranked it?
                       DR. MEYER:  What we did in the end was we
           agreed on some -- I forget what we call them -- but
           some scoring criteria, and we went back and had a
           little formula for deciding two things about a
           particular phenomenon.  If it was important and if it
           was well known because we would address both of those
           at the same -- you know, in the same discussion, and
           what you're really looking for are things that are
           believed to be important and not well known, and those
           are the items that you ought to focus on.
                       And the tables are so large that we
           developed a little formula and put the numerical score
           in the table.  So you could run down the table and
           pick these out.
                       And that's exactly what I did in
           developing this implications report that I prepared,
           was I went down the tables, and I skimmed off the
           items that were of high importance and not well known.
                       You also sometimes find something from the
           inverse of that.  You look for a subject that is not
           thought to be very important that you might have felt
           was important, and I have one of those on this list.
                       DR. KRESS:  The final product is you're
           looking for where you need more research or finally
           decide --
                       DR. MEYER:  Well, some people would use it
           that way.  What I was looking for was insights on how
           I could plan a way to resolve the issue, and it
           involved doing additional work, but it also involves
           a method to get there.  So that was -- I mean, you
           could do a lot with the PIRT, and the information is
           all recorded.  So you can do other things as well, but
           that's what I tried to do with it.
                       So let me try and move through this now,
           and you'll look at some of these items here and see
           that they're perfectly expected results, but not all
           of us knew all of these things at the outset.
                       The first one, for example.  I have to
           confess that I saw this as a little bit of a surprise. 
           I always thought that, you know, the energy deposition
           was just a function of something that could never be
           changed, and if you went over 280 or 220 or 100,
           whatever it was, you were just out of luck.
                       But core designers know that that's not
           the case.  You can design the core.  You can put high
           burnup rods near or far from high worth control rods
           and do other things.
                       Another thing where a real light bulb went
           off had to do with that discussion and with the
           calculations that David Diamond was doing for us on
           the rod ejection accident.
                       We have believed for some time now that
           the 280 calorie per gram number should come down in
           the neighborhood of 100 or 80 calories per gram for
           high burnup fuel, and so we asked David Diamond to do
           calculations of a rod ejection accident where he gets
           100 calories per gram deposited in the fuel rod.
                       And so he makes the presentation to the
           PIRT group members, and somebody asked him what
           control rod worth did you assume, and he says, "Two
                       And you hear a chorus of utility people
           and others say, "There's no way you can have a control
           rod worth two dollars and 50 calories per gram,
           $1.20."  Well, maybe.
                       And so the idea comes up that perhaps for
           screening a large number of operating reactors, the
           current ones up to the current burnup limit, that
           maybe we can do some generic calculations based on
           some enthalpy limit in the range of 80 to 100 calories
           per gram, discover something about the core design
           that you would have to have in order to achieve that
           energy deposition, and then use those to screen the
           reactor population.
                       And if, for example, you have to have two
           dollar control rod worth, and NRR knows for sure that
           we don't have two dollar control rod worth out there,
           then you're done.
                       DR. BONACA:  I have just a question.  Did
           the group discuss the high level objectives that set
           the --
                       DR. MEYER:  Yes.
                       DR. BONACA:  -- pure enthalpy limit?
                       DR. MEYER:  Yes.
                       DR. BONACA:  I seem to remember in ancient
           times as you said one of the concerns was challenge to
           the vessel.
                       DR. MEYER:  Yes, we did, and this is where
           that first meeting went, and so I probably shouldn't
           characterize it as a waste of time, but we started out
           considering the general design criteria.
                       There are two general design criteria that
           govern these two event, 23 and 27 or something.  I
           forget the numbers, but one on the LOCA and one on the
           rod ejection and rod drop accident.  And they talk in
           terms of maintaining coolable core geometries, of
           pressure pulses that don't damage the vessel more than
           just a little bit of yielding or something like that.
                       And for the first couple of days we
           decided how we could adopt those directly as the high
           level criteria for the ranking exercise, and a
           conclusion from that discussion was that was going to
           be really difficult because neither the codes that we
           were looking at, nor the experiments we were
           considering would take you all of that distance.
                       We were not looking at codes that
           calculated the coolability of a debris bed, and we
           were not looking at experiments that would get
           pressure pulses large enough to threaten a pressure
                       And so as a practical matter, we backed
           down to another level, which seemed to be
           conservative, but workable, and probably not
           penalizing in any significant way, and we ended up
           using a concept of fuel damage with significant fuel
                       So we know that there's going to be some
           fuel damage, and that's not a problem, but it's the
           fuel dispersal that's the problem, whether you're in
           a loss of coolant accident where you fragment the
           cladding and you lose the structural geometry of the
           core, you get fuel spilling out or in a very high
           energy rod ejection accident you actually expel fuel
           through the cracks.
                       And so those were things that could be
           addressed with the codes and the experiments that we
           were talking about until we settled down to that
           level, and we used that throughout.
                       DR. CRONENBERG:  I think you might want to
           respond.  Didn't you have a tutorial?  Even though
           these were experts, there were some tutorials on -- by
           like Phil MacDonald -- on experience, fuel behavior
           experience for the various accidents; is that correct?
                       DR. MEYER:  Yes, that's right.
                       DR. CRONENBERG:  For each one of these?
                       DR. MEYER:  We tried to do this with each
           of the PIRTs.  We would start out the PIRT discussion
           with two or three tutorials.  Phil MacDonald gave one
           of them on the reactivity accidents.
                       David Diamond back here in the audience
           gave one on the same subject.
                       Larry Hochreiter gave a couple on PWR loss
           of coolant accidents.
                       Jens Andersen from GE talked about LOCAs
           and also about the power oscillations.
                       So we had a lot of tutorials.  We, in
           fact, used a court recorder for most of the sessions. 
           We captured the tutorials on transcript, and we took
           the transcripts and edited the transcripts, send them
           back to the authors, the presenters for editing, and
           included a select number of those presentations as
           appendices in these PIRT reports.
                       So those tutorials, some of them, are in
           the PIRTs.
                       DR. KRESS:  Ralph, how many calories per
           gram does it take to go from normal operating
           temperature up to fuel melt temperature?
                       DR. MEYER:  It takes -- fuel melting is
           about 267 calories per gram and normal operating fuel
           enthalpy is -- it's in the range of 15 or 30.  So it
           takes a lot, 230 or 240 to get to melting.
                       And you know the technical background
           here.  Originally with fresh materials we thought that
           you had to start melting something to get some real
           action, and with high burnup cladding, you see a
           completely different mechanism come in where the
           expansion of the pellet against the cladding, which
           has lost a lot of its ductility results in splits, and
           you also then have the gassy microstructure of the
           pellet, which can blow particles out through these
                       So that's the kind of thing we've see. 
           Well, okay.  Some other results of the PIRT was the
           majority thought that you needed to run tests in the
           burnup range that you were really looking for because
           part of the action is in the cladding, but part of the
           action is in the pellet, and even if the properties of
           the cladding are dominated by oxidation or hydride
           distribution, the loading is going to be determined by
           the pellet, which is affected by burnup.
                       We talked a fair amount about testing the
           MOX rods because of plutonium enriched agglomerates. 
           This was a subject where there really wasn't any big
           change in views because we all knew this going in, and
           we knew it coming out.
                       Testing in the right coolant environment,
           we talked about that before, and that came out highly
                       This one is a little bit of a surprise for
           the reactivity accidents, the PIRT panel members
           didn't think that the alloy was such a big deal, but
           this was in the context of did you have to run an
           integral test like in the Cabri reactor or the NSR
           reactor.  Did you have to run those tests for all
           different alloys?
                       And their thought was, no, probably not. 
           As long as you knew the relative mechanical
           properties, you could extrapolate from some base case,
           and so, in fact, the cladding alloy was not ranked
           high, although you might have expected it.
                       Also, near the end of the discussion of
           the rod ejection accident, we realized that there may
           be some of the newer alloys which have so much
           ductility even at high burnup that they don't fail by
           this pellet cladding-mechanical interaction, and in
           those cases, then you would be able to go on up to
           higher energy depositions before you failed, and that
           the phenomena that would come into play would be more
           like the high temperature transient effects in a loss
           of coolant accident.
                       And we have some experience with the
           Russian cladding that showed that.  The E110 Russian
           cladding that was tested in IGR reactor and later with
           short pulses in the BIGR reactor always shows
           ballooning type deformation and gas pressure rupture
           rather than a PCMI, even at 55 or 60 gigawatt days per
           ton.  The stuff is very ductile.
                       DR. BONACA:  I am still surprised that you
           did all this work and there was no linkage to some
           high level objectives as discussed before.  Two,
           eighty used to be, if I remember, was a true
           threshold.  If you demonstrated that you were below
           that, you didn't have to consider effects on the
           vessel.  For example, the pressure pulse that may
           cause a challenge to the vessel were all issues of
           coolability, too.
                       I understand what you're doing.  You're
           trying to say, well, you know, pragmatically let's go
           to a lower value.  To accomplish what?  I mean, it's
           not clear yet that you have linked a value, whatever
           value you're searching for, to a high level objective
           such as coolability or pressure pulse.
                       And without that, you could always have
           the industry coming back and saying, "Well, I want to
           go to 70,000 or 80,000 megawatts per metric ton," and
           there is no basis for 100 calories per gram.
                       DR. MEYER:  Yeah, yeah.  Well, we talked
           about that, and we decided as a practical matter to
           tie it to fuel dispersal.  If you don't have fuel
           dispersal, you're not going to have pressure pulses
           because you won't have a fuel-coolant interaction.
                       DR. BONACA:  Okay.
                       DR. MEYER:  And you won't lose coolable
           geometry.  So we tied it to fuel dispersal, and I
           think there was a general belief that if you work with
           an enthalpy level that corresponds to fuel dispersal,
           that you will always be able to get under that
           comfortably and won't be penalized.
                       DR. BONACA:  Oh, okay.  So you have a
           linkage to that.  I mean --
                       DR. MEYER:  There is.  Yes, there
           definitely is.
                       DR. BONACA:  Because I haven't heard the
           NUREG so I don't know, but all right.
                       DR. MEYER:  Okay.  Now, I can't remember
           whether I discussed this last year or not.  So I'll
           just go through it very, very quickly, but the idea
           now to bring some resolution to the reactivity
           accident is, first of all, to improve an empirical
           correlation that we have, and you've seen it before. 
           I've stuck it in as the next slide.  This is what we
           call our paint brush slide.  It's not really a
           correlation yet.  It's just sort of a failure map of
           the tests that have been done.
                       But it's that kind of a plot that we would
           look at and try and draw some boundary between
           survival and failure, looking at enthalpy increase as
           a function of either oxide thickness or some
           fractional oxide cladding thickness to accommodate
           different cladding diameters.
                       DR. KRESS:  What do you do with those
           black dots that are below the line?
                       DR. MEYER:  Yeah.  Well, this is kind of
           reminiscent of NUREG 0630 and the ballooning and
           rupture data from before.  You have to know the
           personality of these data points to realize that these
           things ought to be moved up on the plot.
                       Those were tests in NSRR.  They were
           tested at room temperature.  The accident isn't at
           room temperature.  It's at hot zero power, which is
           pretty hot.  It's about 280 or 300 degrees Centigrade. 
           So there's a big ductility.
                       DR. KRESS:  It just tells you you've got
           the wrong parameters plotting.
                       DR. MEYER:  Well, in the past in the NSRR
           reactor, they've only been able to test at room
           temperature because they didn't have a high
           temperature capsule, but now they're building a high
           temperature capsule.
                       And one of the things that we want to wait
           for are some data from the high temperature capsule
           because if they can quantify how much too low their
           room temperature test was, then we have a basis for
           bringing these up.
                       Here's another one.  This is REP Na-1. 
           This is the very first test done in the Cabri reactor. 
           Then intense discussions going on still to this day.
                       DR. KRESS:  That's the one that got
           everybody excited.
                       DR. MEYER:  Got everybody excited, and it
           probably is an anomalous result.  I think we
           understand this one now.  The understanding that we
           believe we have is not universally accepted, but it
           looks like that the precondition of that fuel rod was
           at such a high temperature that it caused hydride
           redistribution that affected the ductility.
                       We've been looking at that at Argonne
           National Laboratory and have been discussing it as
           recently as two weeks ago, a full day meeting, and
           it's very controversial because this was a pitfall
           that was recognized.
                       When they prepared this rod, they realized
           that they shouldn't take it up too high in temperature
           before the test and thought they had kept the
           temperature low enough, and the only thing we can
           conclude is either their temperature measurement
           wasn't real good or we just didn't quite understand
           where this boundary was because it seemed inescapable
           when you look at the microstructures before and after
           the test, that the hydrides were redistributed before
           the test.
                       DR. KRESS:  That's why I thought maybe you
           had the wrong parameter.  Oxide thickness must be a
           surrogate for --
                       DR. MEYER:  Oxide thickness -- well, it's
           largely the hydrides that affect the ductility in this
           temperature range, and the --
                       DR. KRESS:  -- and ductility of the
           remaining material in the clad or something.
                       DR. MEYER:  You've got a little bit of
           LOCA thinking coming into that question about the
           remaining metal thickness.  It's --
                       DR. KRESS:  Well, those are only microns,
           aren't they?  Yeah.
                       DR. MEYER:  Yeah.  This is the --
                       DR. KRESS:  Pretty much.
                       DR. MEYER:  This is the corrosion.  This
           is the amount that was accumulated during normal
           operation, and approximately 15 percent of the
           hydrogen that is released during the dissociation of
           steam that results in the oxidation.  So about 15
           percent of the hydrogen that's formed is also
                       DR. KRESS:  So it's a surrogate for the
           amount of hydrogen --
                       DR. MEYER:  That's exactly right.
                       DR. KRESS:  Okay.
                       DR. MEYER:  That's exactly right.
                       DR. KRESS:  Thank you.
                       DR. MEYER:  It's easy to measure the oxide
           thickness.  It's hard to measure the hydrogen
           concentration.  It's a surrogate for hydrogen.
                       CHAIRMAN POWERS:  I guess what puzzles me
           a little bit about the discussion of REP Na-1 is,
           okay, these guys tried very hard not to redistribute
           the hydrogen, but despite their best intentions, they
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  Okay.  Does that mean
           that hydrogen can never be redistributed in a real
                       DR. MEYER:  Well, it is distributed in the
           real core in a very characteristic way because you
           have a temperature gradient across the cladding and
           the hydrogen congregates to the cooler outer shell,
           and this tends to embrittle the rim of the cladding,
           but leave a lot of ductile material underneath, and
           when you look at the fracture surfaces, this is
           exactly what you see.
                       You see a blunt cracked tip through the
           hydrided rim, and then a 45 degree shear through the
           ductile part of the cladding, and what you saw in REP
           Na-1 was a blunt cracked tip throughout the specimen. 
           It's the only one that looked like that.  It's the
           only specimen that they took the temperature up to 390
           degrees Centigrade during preconditioning.  All of the
           rest were kept at much lower temperature.
                       I don't know if there are any conditions
           in the reactor that could do that.  What we are asking
           ourselves though is if there are conditions during
           vacuum drying for storage which could cause this to
           happen because this redistribution happens when you
           don't have the normal pellet expanding putting stress
           on the cladding, and in the storage casks when they
           dry them, you get -- I don't know the exact numbers,
           but I've heard them talk about numbers in excess of
           400 degrees Centigrade sometimes.
                       And so I think one of the things that we
           have fed back from this experience into the dry
           storage work that we're doing is to look specifically
           at the ductility of this material after it's gone
           through a range of vacuum drying conditions, in
           addition to just looking at the creep rupture, which
           is what is currently used to get the limits for dry
                       CHAIRMAN POWERS:  The redistribution of
           hydrogen that you're talking about, it's really an
           equilibrium phenomenon.  It's driving itself from
           being dispersed hydrides along the grain boundaries
           into a more coherent hydride to reduce surface area of
                       So, I mean, the hydride redistribution
           that you want, I mean, it wants to do this, and it's
           just a question of whether you have enough temperature
           and time for that to accomplish.
                       DR. MEYER:  That's right.
                       CHAIRMAN POWERS:  So there's a time-
           temperature tradeoff here.
                       DR. MEYER:  Right, right.
                       CHAIRMAN POWERS:  And it's not clear to me
           that you don't have time even though you might have
           modest temperatures --
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  -- to accomplish that in
           a real reactor.
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  In which case it would
           not be an anomalous point.  It would be characteristic
           of a point where there had been redistribution of the
                       DR. MEYER:  Well, the only thing I can say
           is there have been a lot of rods looked at out of the
           reactor, and they have this characteristic high
           hydrogen concentration near the OD.  They do not look
           like this one did.
                       DR. KRESS:  The higher burnup implies
           they're going to stay in there longer.
                       DR. MEYER:  Implies that?
                       DR. KRESS:  Those high burnup rods will
           stay in there longer and will have more time to
           potentially redistribute the hydrogen.
                       DR. MEYER:  Yeah, well --
                       MR. SCOTT:  Ralph, also the orientation. 
           I mean there's always hydrogen, but sometimes the
           orientation of what the hydrides look like --
                       DR. MEYER:  Yeah.
                       MR. SCOTT:  Is that part of it?
                       DR. MEYER:  It certainly can be part of
           it, but in this case, Hee Chung (phonetic), who is
           examining this issue, has not made the reorientation
           a big issue.  The orientation of the hydrides is
           affected by the street that you apply to the cladding
           when it's hot enough for the hydrides to be mobile,
           and he's not arguing that they reoriented from
           circumferentially aligned stringers to radially
           aligned stringers, which right away will really ruin
           your ductility.
                       There just seems to be a redistribution,
           a sort of homogenization of the hydrides.  They are no
           longer all packed up on the OD, and there are a few
           radial ones, but it's not predominantly radial.
                       It just looks like you annealed it and
           gave it a chance to relax the highly organized
           distribution into a more random distribution.
                       DR. KRESS:  Those are predominantly axial. 
           You said circumferential.
                       DR. MEYER:  When you look at them in
           cross-section, they are stringers around the
                       DR. KRESS:  They are circumferential?
                       DR. MEYER:  Yeah.  So to try and wrap this
           one up, what we want to do is improve the correlation,
           to get mechanical properties for all three of these
           because the correlation is predominantly Zircaloy, and
           so we have to have the relative mechanical properties
           of all of these, use our FRAPTRAN code to try and make
           the adjustment for the mechanical properties
           differences, and then use the three dimensional
           neutron kinetics code to do the plant analysis and
           hopefully relate some enthalpy limit to control rod
           worth or some other parameters that could be easily
           used to screen the core.
                       DR. KRESS:  Well, does FRAPTRAN deal with
           the hydrization of the plant?
                       DR. MEYER:  That's going to be just
           imbedded in the mechanical properties.  The mechanical
           properties are being measured under the conditions --
                       DR. KRESS:  You'll input mechanical
                       DR. MEYER:  That's right, and the
           mechanical properties for the reactivity accident,
           which compared with the LOCA these are low
           temperature, high strain rate, whereas the LOCA are
           going to be high temperature, low strain rate.
                       The mechanical properties for ZIRLO and M5
           are going to come from the Cabri program.  We have a
           commitment from ENUSA in Spain to provide a ZIRLO rod
           for testing in Cabri and a commitment from Framatome
           in France to provide an M5 rod, along with the
           permission to do mechanical properties testing on
           these and provide all of that to the participants in
           the Cabri program.
                       And these, there will be one test of each
           of these in 2002.  That's next year, in the sodium
                       CHAIRMAN POWERS:  And one test, and the
           uncertainty in the outcome is?
                       DR. MEYER:  I'm sorry?
                       CHAIRMAN POWERS:  What's your uncertainty
           in your outcome when you have one test?
                       DR. MEYER:  Large, but we have --
           hopefully we'll have ample mechanical properties
           measurements, and we'll have other tests.  We have all
           of these other tests with Zircaloy.
                       I know it's not going to completely
           satisfy you in terms of the quality of this
           correlation, but what my proposal is to my office,
           which is trying to resolve this issue, is that we go
           ahead in 2003 and try and go through the exercise and
           see if we get an answer that's favorable.
                       I think the answer is going to be
           favorable.  This is one where we now have enough
           information to have a "seat of the pants" idea of
           where it's going, and hopefully the margin will be
           enough that we can discuss the uncertainties and see
           where we are.
                       The reason for pressing to do this in 2003
           is that there's going to be a three-year delay before
           the water loop starts, and I think it's better for us
           to go ahead and try and go through the resolution with
           what we have from the socium (phonetic) loop and from
           NSRR and hopefully a few tests and a high temperature
           capsule from NSRR.
                       We're going to be on a plateau of
           understanding for at least three years, and so we
           might as well go ahead and try and go through the
           exercise, see if we can finish it off, and then when
           we get to the water loop if we see any surprises, then
           we'll go back and make an adjustment.
                       DR. CRONENBERG:  So what is it, 2003 you
           go to the standard review plan and say for 50,000
           megawatt days per ton, the enthalpy will be 100
           calories per gram and anything less it remains 280 as
           in the original review plan or what?
                       DR. MEYER:  I can't say that that's what
           we would do.  What I'm saying is that in 2003 that the
           Office of Research will try and write a paper of some
           sort that says we have assessed the operating reactors
           with the current fuel up to the current burnup limit,
           and we have this database.  We think the enthalpy
           limit -- a reasonable enthalpy limit to use for this
           is such-and-such.  We've done the neutron kinetics
           calculations.  Everything is honky-dory.  We have some
           big uncertainties.  There will be some additional work
           in the future to look for mistakes.  Case closed,
           and --
                       DR. CRONENBERG:  But case closed means we
           remain with 280 calories per gram?
                       DR. MEYER:  That would depend on how I
           think NRR wants to handle this, and we haven't had any
           discussion on that.  How you implement this into the
           regulatory framework is another step.  At the moment
           I'm just talking about establishing the technical
           basis to do it.  
                       I would expect during the same time period
           that the NRR will address the regulatory guidance and
           maybe even the Office of Research might be asked to do
           that.   I just don't know.
                       DR. CRONENBERG:  There's things on the
           docket now that are kind of pressing, like the power
           upgrade for I don't know if it's Commonwealth Edison
           anymore, but the Dresden, Quad Cities.  They're going
           for 17, 20 percent power upgrades with extended fuel
           burnup.  I think with the new GE design to above 50 or
           55, maybe even 62.  So where does research come into
           play with NRR that NRR has to review these
                       DR. MEYER:  Ralph Caruso from NRR wants to
           answer your question.
                       MR. CARUSO:  I just wanted to make the
           comment about the power up rates.  The power up rates
           for the BWRs do not involve raising any of the burnup
           limits above 62,000.  They do not involve changing any
           of the burnup rates for any of the fuel.
                       DR. CRONENBERG:  Okay.  I guess it's more
           on the power oscillations when we get to the BWRs, not
           this rod ejection, but still I'm sort of seeing how
           the research falls into near term licensing, licensing
                       MR. CARUSO:  Well, right now what we're
           doing is we're following the work that's being done by
           the Office of Research, and we take it into account as
           we make our licensing decisions.
                       But right now none of the power up rates
           involve any changes to any fuel licensing limits. 
           We've not changed any fuel licensing limits to
           accommodate the power up rates.
                       DR. CRONENBERG:  So you look at the
           standard review plan as it is written right now, and
           that's what you base your review on, the 280 calories
           per gram.  If PWR comes in, what is it?  Two, thirty
           or BWR?  It's all based upon the old standard review
                       MR. CARUSO:  The vendors have approved
           methodologies for their existing fuel designs, and
           they are going to continue to use those approved
           methodologies to analyze the behavior of the plants at
           the higher power levels, and as long as they continue
           to meet the standards that have been already approved
           at those higher power levels, we'll find them
                       MR. ROSENTHAL:  Yeah, Jack Rosenthal,
                       You have to do this very piecemeal.  Okay? 
           For the ejected rod, if you say that the limiting
           ejected rod action is at hot zero power because at hot
           full power you have far less rods in the core, then
           the fact that when you are at full power you're going
           to be running at a higher power doesn't enter into
           that hot zero power calculation.
                       Like I said, you just have to piecemeal it
           through, you know, think it through event by event and
           what's limiting with.
                       CHAIRMAN POWERS:  It's what I'm still
           wrestling with a little bit, Ralph, is how one selects
           the fuel and clad combination that one would test. 
           Grant you you cannot test all conceivable clads, all
           conceivable fuels, all conceivable degradations of
           that clad, and you get around that by saying, well,
           I've got these computer codes that are going to allow
           me to extrapolate and interpolate within the data set
           I've got, but the question comes up:  which one do I
                       Do you test a representative piece of a
           rod, or do you test the worst piece of a rod?
                       DR. MEYER:  We have done both, but we're
           generally focusing now on the worst piece of the rod. 
           The worst piece of the rod is -- well, the one that we
           select is the uppermost span between grids where the
           power is still level.  So we don't take the end where
           you have a big power gradient, but we take the next
           one.  It's from the hottest elevation in the core.  It
           has the highest oxidation on it of the other grids,
           and those are the ones that we almost always select
                       We had some interesting -- we had three
           pairs of tests.  If you go back and look at both the
           NSRR and the Cabri test, you can find three pairs of
           tests were -- Span 5 and Span 3 were tested, and each
           of those three pairs, the Span 5 failed, and the Span
           3 didn't fail.  They had exactly the same burnup
           level, but their oxide thicknesses were quite
                       CHAIRMAN POWERS:  Okay.
                       DR. MEYER:  Okay.  Can I go on to the --
                       CHAIRMAN POWERS:  Please.
                       DR. MEYER:  -- the next one?  I'm a little
           anxious about the time here.
                       CHAIRMAN POWERS:  Well --
                       DR. MEYER:  But I'll go on.
                       So the next PIRT that we did was for
           boiling water reactor and for power oscillations that
           were not stopped by a SCRAM, and this is an accident
           for which we do not have clear regulatory guidance,
           but for which GE has in the past done some analysis
           and have used the same 280 calorie per gram limit to
           show adequacy in this analysis.
                       And that limit probably -- it either
           suffers from the same problems that it does for the
           PWR or maybe it's not appropriate at all for this
           event, and so we just worked our way through this
           event with some interesting understanding of an event
           that hasn't been understood very well before, at least
           from the point of view of fuel behavior.
                       Just a few basics.  The accident that we
           considered started at about 85 percent power, and the
           recirculation pumps tripped, and then you got some
           oscillations and you didn't get a SCRAM.  So the
           oscillations build.
                       Now, the oscillations come at about three
           second intervals, and this three second interval, two
           to four seconds what's seen in all of the analyses
           that have been done.
                       It takes about eight seconds for a fuel
           rod to transfer its heat out.  So this is less than
           the time constant of the fuel rod.  So if you look at
           this part, it looks like the rod ejection accident on
           a small scale.  These little pulses have about 15,
           one, five, calories per gram in them instead of 50 or
           100 calories per gram.
                       And so they cause the cladding temperature
           to start warming up, and it starts to cool down, and
           it warms up again, and pretty soon it gets to a high
           temperature, and the experts expected that you would
           get to a point where you would dry out and you would
           not rewet.
                       And now you had a transient that looks
           something like a LOCA transient.  
                       So the opinions and insights that we got
           from discussing this accident are highlighted here,
           was nearly a unanimous feeling among the experts that
           you would not get failure by this mechanical
           interaction of the expanding pellet pushing on an
           embrittled cladding because the energy was just too
           small in that pulse, and by the time you get to the
           second pulse the cladding is now heated up and it's
           more ductile, and so forth.
                       They did expect that you would eventually
           get a high temperature transient during which you
           would have oxidation, high temperature oxidation,
           something like you have in a LOCA, and you might even
           have ballooning and rupture depending on the pressure
           in the rod.
                       The BWRs I don't think tend to run quite
           as high a differential pressure as the PWRs, but I
           believe they do use the same liftoff criterion.  So
           there can be a positive pressure differential, but it
           might be a negative pressure differential.
                       If you get this kind of high temperature
           excursion with oxidation, you would get classing
           embrittlement just like you do in the LOCA.  There was
           a fairly lengthy discussion about what bad things do
           we have to worry about.  Do we have to worry about
           embrittlement of the cladding?  Do we have to worry
           about melting of the cladding?  Do we have to worry
           about melting of the fuel pellets?
                       It was decided that we don't have to worry
           about melting of the cladding or melting of the fuel
           pellets because you're going to embrittle the cladding
           at a far lower temperature than those two events, and
           so what we really have to look at it embrittlement of
           the cladding.
                       I did not expect runaway oxidation.  We
           had a number of discussions on that.  There doesn't
           seem to be any magic temperature at which you get some
           autocatalytic reaction that runs away.  It's simply a
           matter of heat balances, how much heat from the
           chemical process and how much can you pull away?
                       And it was not thought that that would be
           a problem, particularly since we're going to run into
           our problem at a fairly low temperature.  Well, fairly
           lower temperature means around 1,000, 1,200 degrees
                       And it was further thought that LOCA-like
           criteria may be even the LOCA criteria, might just
           apply to this transient.
                       DR. BONACA:  I assume that this event is
           bounding with respect to a drop for BWR?
                       DR. MEYER:  We decided to focus on the
           power oscillations a couple of years ago when we did
           our little agency program plan Commission paper, and
           we focused on this as a result of our perception of
           the risk.
                       We looked at the probability of occurrence
           and the risk, and what we know is the power
           oscillations without SCRAM are  a -- I don't want to
           overstate it, but they're a significant risk
           contributor in BWR PRAs, whereas the rod drop is not. 
           The rod drop is of very low frequency.
                       So we just focused on this one.  I think
           that, in fact, a lot of what we learn for the PWR rod
           ejection accident in terms of fuel behavior and damage
           limits can be transferred, but not all of it because
           the Japanese continue to study BWR power pulse events
           and have recently looked at some high burnup BWR
           cladding in their NSRR reactor and find unusual
           behavior that hasn't been seen before that seemed to
           be related to the bonding between the pellets and the
           classing, which in the BWR cladding that they were
           looking at has this soft zirconium liner on the ID.
                       So, you know, working is going on on
           things that aren't at the center of focus for some
           regulatory agency, and we're plugged into it.
                       DR. BONACA:  The reason why I asked it,
           yeah, was that maybe embrittlement is not the issue if
           you have that kind of transient.
                       DR. MEYER:  Well, I guess it might not be,
           but the group of experts thought that that was going
           to be the issue, and so following that --
                       DR. BONACA:  Even for rod drop?  Okay.  I
           just --
                       DR. MEYER:  Well, for this -- well, look. 
           For the rod ejection accident, embrittlement is a
           different -- it's embrittlement from a different
           temperature range from a different cause, but it's
           still embrittlement.
                       Anyway, now --
                       DR. SHACK:  But you're not proposing to
           use LOCA type embrittlement criteria for a BWR rod
           drop.  I mean --
                       DR. MEYER:  Not for BWR rod drop.
                       DR. SHACK:  You got rid of that on your
           frequency argument.
                       DR. MEYER:  Right, right.  I think what we
           tend to do is if BWR rod drops continue to be
           analyzed, you'd probably use the criteria that emerge
           from the PWR
                       DR. BONACA:  Okay.  Because, I mean, right
           now still in the FSAR if you were licensing a plant
           today, you would still have to analyze rod drop.
                       DR. MEYER:  Right.
                       DR. BONACA:  Not necessarily power
           selection.  That's why I was leaving that --
                       DR. MEYER:  Again, this is some decision
           that NRR would make and that --
                       DR. BONACA:  So you would have to infer an
           equivalent temperature or enthalpy, the position from
           the PWRs, and I was intrigued by that process, how you
           would go from one to the other.
                       DR. MEYER:  I think it would make sense to
           use the criteria that are developed for the PWR for
           the BWR rod drop.
                       DR. BONACA:  Okay.
                       DR. MEYER:  Although there may be some
           differences because of the cladding.
                       Now, for the power oscillations, we are
           still lagging behind on attacking this issue.  This is
           the one that we know the least about and that we're
           doing the least on, but it looks like that resolution
           of the power oscillation question is going to depend
           largely on analysis.  We're going to have to calculate
           our way through a high temperature transient and look
           at dry-out and rewet and cladding oxidation.
                       We have talked to JAERI, the Japan Atomic
           Energy Research Institute, about doing some repeated
           pulse test just to confirm that the pulse part of this
           isn't playing a role, and hopefully they'll be able to
           schedule a few tests like that in the next two or
           three years.
                       DR. UHRIG:  That would be in that three-
           year reactor that they have?
                       DR. MEYER:  Yes, yeah.  We talked at
           length about the test, and they don't have to do them
           every three seconds.  They might do them every three
           days.  They just do one, leave it in there, raise the
           temperature up a little bit and do another one, and if
           you do two or three of these, you can probably see
           what is going to happen or not going to happen, and so
           that's the kind of repeated pulse testing that's being
           talked about for NSRR.
                       Halden has done a number of dry-out tests,
           and are interested in doing a test specifically
           planned for this BWR event.  We're trying to help plan
           that test.  I wouldn't say that we're very far along,
           but the capability is there.  The interest in the
           project, in doing this kind of testing is there, and
           if we can get our act together and define a good test,
           I think they will do the test as part of the joint
                       CHAIRMAN POWERS:  When you think about
           these ATWS and the embrittlements that occur, do you
           think about the ATWS processes?
                       DR. MEYER:  I'm sorry.   I didn't
           understand you.
                       CHAIRMAN POWERS:  The ATWS recovery
           processes, you know, where you drop the core down and
           then try to promote mixing by raising the coolant
           level back up.
                       DR. MEYER:  I'm afraid the only thing that
           we considered was that some time the process, the
           oscillations would stop, but we did not look at the
           process of stopping in any detail.
                       DR. KRESS:  You probably don't do much
           more oxidizing of the clad.
                       CHAIRMAN POWERS:  It's not the oxidizing
           that I'm worried about.  You know, bring the core down
           and then bringing it back up to prolonged mixing where
           you must be putting some sort of forces on the clad.
                       DR. KRESS:  Yeah, looking at forces on it,
                       DR. MEYER:  Yeah, but see, these are
           exactly the considerations that we're talking about
           now for LOCA.  What are the forces on the rods and how
           do you cover?  And we'll get to that in just a few
                       DR. KRESS:  It looks to me like, Ralph,
           with the frequency of these oscillations for BWRs
           being what they are the only difference between that
           and the single pulse is just the integrated energy
           that you put in, other than how you deal with it
           otherwise, put different forces on it.
                       DR. MEYER:  Well, the second thing is only
           the first one is going to take place with cold
                       DR. KRESS:  Yeah, and then you're heating
                       DR. MEYER:  And then you're heating up,
           and you're less vulnerable to the brittle failure.
                       DR. KRESS:  Yeah.  So I think this would
           be amenable to calculation rather than --
                       DR. MEYER:  Yeah.  Well, that's what we
           hoped, and the code, the code that we're hoping will
           solve this is a combination of our FRAPTRAN code and
           a code you might not have heard of before called
           GENFLO, which is a Finnish, sort of a utility
           thermohydraulics code that has been coupled in Finland
           with FRAPTRAN more or less specifically to do this
                       Keijo Valtonen, who is known by a number
           of people here at NRC as the principal person at STUK
           in Finland who is doing this with support from their
           laboratory at VTT, and just a couple of weeks ago I
           was given two reports on the progress of this, and I
           want to say to you that this is a completely voluntary
           effort on the part of the Finns.  We don't even have
           a formal agreement with them on this, but we have been
           working cooperatively with them on a voluntary basis
           for four or five years.
                       They're doing actually more work on this
           than we're doing, and so, you know, if you have any
           interaction with people from Finland, tell them the
           research people certainly appreciate this.
                       MR. ROSENTHAL:  Let me just make the point
           that you know, you use the systems code like RELAP or
           TRACK to drive a hot channel code, to drive a fuel
           code in an integrated, you know, sequence and
           calculation.  When we're all done, we're still going
           to have to sit back and say what do we really know,
           and we're planning that.
                       And so that, you know, I mean, it's still
           a piece of work to do, and we shouldn't be dismissive
           of it.  I mean, we'll do the work, but it's --
                       DR. CRONENBERG:  Can you run fuel codes or
           do you use still contractors to do most of your
           FRAPTRAN or can you do it in house now?
                       DR. MEYER:  We do it in house.
                       DR. CRONENBERG:  Okay.
                       DR. MEYER:  I don't want to oversell
           either the capability of the code or our in house work
           at this time, but we do run both of the codes, FRAPCON
           and FRAPTRAN.  We are running LOCA scenarios and ATWS
           scenarios in house and at the lab.
                       DR. CRONENBERG:  And at PARCS is Purdue
           still doing that or you guys can run that yourself?
                       DR. MEYER:  Gee, I don't know whether
           anybody on the staff can run it, but David Diamond at
           Brookhaven is doing the rod ejection calculations for
           us.  PARCS is a Purdue University developed code, but
           it's run other places, and David runs it at
                       MR. ROSENTHAL:  And as we speak, we're
           moving PARCS into TRACK M as an integrated product.
                       DR. CRONENBERG:  So you'll be able to run
           that in house.
                       MR. ROSENTHAL:  Yes, sir.
                       DR. MEYER:  Okay.  I'm well behind now. 
           So let me move on and talk about the loss of coolant
           accident where we have both embrittlement criteria and
           evaluation models.  EM stands for evaluation models. 
           PCT is peak cladding temperature, and ECR is
           equivalent cladding reactant.  That's the jargon of
           the LOCA trade.
                       The PIRT tables for the loss of coolant
           accident were extremely long, and I only skimmed off
           a couple of things of interest here.  One was it
           surprised me that these fuel experts who had also some
           experience with the large system codes -- at least
           some of them did -- they identified a lot of thermal
           hydraulic models that were of high importance and not
           well understood, and these are the traditional thermal
           hydraulic models that are in our LOCA code.
                       CHAIRMAN POWERS:  You don't even need to
           understand the momentum equation.
                       DR. MEYER:  So I just had to point that
                       CHAIRMAN POWERS:  We're desperate.
                       DR. MEYER:  They also found that for the
           loss of coolant accident that the cladding type was
           very important, but the most interesting result of the
           discussions on the loss of coolant accident was the
           second bullet where George Hache from IPSN in France
           got up and gave us a summary of our own U.S. history
           of the development of the ECCS criteria and reminded
           us that the embrittlement criteria, these numbers
           2,200 degrees Fahrenheit and 17 percent oxidation
           were, in fact, based on ring compression tests made by
           Hobson in the early '70s, and that the quench tests
           were only confirmatory because there had been a lot of
           discussion about whether the quench tests could
           reasonably represent the axial forces or other
           constraints that might be on a fuel rod during the
                       I should say that another way.  The
           discussion was that the external forces on the fuel
           rod, whether they come from the quenching process or
           from some other source, including things like
           earthquake, could be adequately represented in these
           quench tests.  It was felt that they could not, and so
           the quench tests were used only as confirmatory tests,
           and the criteria themselves were derived from these
           ring compression tests.
                       Well, I didn't know that, and I think most
           of the people who knew about the details of the
           development of these criteria during the ECCS hearings
           are retired, and we had not planned such a test in our
           program at Argonne National Laboratory.  So the very
           first thing, you know, as soon as this presentation
           was made, we knew that we had to modify our program at
           Argonne where we had only planned quench tests to
           include some measure of post quench ductility from a
           test, either a ring compression test or something
           better than a ring compression test.
                       So that was the immediate result.  There
           was a sort of delayed reaction to this when in France
           and in my office we discovered some Eastern European
           papers from the early and mid-'90s reporting on ring
           compression tests with the Russian alloy, E110, which
           is zirconium, one percent niobium, which is very
           similar in composition to M5.
                       So all of a sudden light bulbs are going
           off.  Here is some information on a similar alloy that
           shows a marked reduction in the amount of oxidation
           that can be tolerated during a loss of coolant
                       And so this then led to meetings with
           Framatome and Westinghouse.  It led to modification of
           a conference that had already been planned under the
           OECD framework, and you'll hear directly from
           Framatome and Westinghouse on this subject, and then
           I'll come back and give you a summary of the
           conference which focused on that subject.
                       So just quickly to go over some steps in
           trying to resolve this, we do have a test program at
           Argonne National Laboratory with what we think of as
           an integral test or a LOCA criterion test where we
           take a piece of a high burnup fuel rod with the fuel
           inside, pressurize it, run it through a LOCA type
           transient, ballooning rupture, oxidation, cool down,
           quenching, everything present, and try and look at the
                       We also have a number of separate effect
           tests in the same laboratory where we're looking in
           separate measurements of oxidation kinetics and
           mechanical properties, including now the post quench
           mechanical properties.
                       The work started with real specimens last
           summer when we received the BWR rods from the Limerick
           plant, and it's slow going.  We have done a number of
           the oxidation kinetics measurements, and I can just
           give you a qualitative result of that. 
                       Oxidation kinetics seem somewhat faster
           for high burnup fuel than for fresh fuel.  So we get
           oxidation rates that are higher than Cathcart-Pawel
           correlation, for example, whereas when we measure for
           fresh tubing, we can reproduce the Cathcart-Pawel
                       CHAIRMAN POWERS:  And do you exceed Baker-
                       DR. MEYER:  I'm sorry?
                       CHAIRMAN POWERS:  Do you exceed Baker-
                       DR. MEYER:  I don't think so.
                       CHAIRMAN POWERS:  That's harder to do.
                       DR. MEYER:  Yeah, it would be harder.
                       CHAIRMAN POWERS:  But which in a
           regulatory world, that's the one that counts.
                       DR. MEYER:  The Halden reactor is also
           planning to do what we would call an integral test. 
           Take a piece of a fuel rod and run it through a
                       The principal interest in the Halden
           program is to look at the possibility of relocation of
           fragmented fuel into the balloon section, but it,
           again, will allow you to look at a lot of things,
           including oxidation, ballooning rupture.
                       There are a lot of related studies going
           on in Japan and in Russia, and our FRAPTRAN code will
           be used in performing the work, but not in a major way
           in terms of coming to some resolution of this, unlike
           resolving the BWR power oscillations, where it looks
           like our job is going to be to analyze our way through
           the transient.
                       In this case, analyzing your way through
           the transient will be done with the large LOCA codes,
           and our job is limited to just looking at what the
           embrittlement criteria and the modeling for oxidation
           and ballooning and rupture are.
                       We also are interested in doing the same
           kind of testing for ZIRLO and M5 cladding, and in
           fact, in the meetings that were held at the end of
           February with Framatome and Westinghouse, we asked
           them if they would cooperate with us on this work and
           provide the materials, and we'd do the work right at
           Argonne and involve EPRI in the program at the same
           time, and so we're kind of waiting for a response on
                       I think that's all I want to say at this
           time.  There are two other slides in your handout. 
           This one is a list of the work that we're relying on. 
           I put NRC in quotation marks here because we don't
           fund or direct all of these programs.  There's a
                       For example, the JAERI program, we neither
           fund it nor direct the work in it, but we have full
           cooperation with JAERI on this, and they do provide us
           with all the information.
                       Some of these programs we participate in
           as paying members.  The Russian work, we provide a
           portion of their funding and a lot of the direction of
           that work, but this is pretty much a list of the
           research programs on which we will be depending for
           information on fuel behavior.
                       CHAIRMAN POWERS:  One of the questions
           that came up in a previous discussion of the Argonne
           out of pile test was the question of what temperature
           scenario you put them through to simulate the LOCA.
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  And do you track some
           sort of average temperature history or do you try to
           find the temperature history of a particular rod in
           those experiments?
                       DR. MEYER:  I'm not sure that the
           temperatures have been set for this, but our current
           thinking is to run these integral tests at 1,204
           degrees Centigrade.  So we would run them up.
                       We have a linear -- Harold, what is the
           run-up?  Five degrees per second heat-up or is it
           higher than that?
                       MR. SCOTT:  It's about that.
                       DR. MEYER:  Sud knows the numbers for
                       MR. ROSENTHAL:  Let me just offer that we
           need to be thinking this thing through because the
           heat-up rate of the evaluation model, large break
           LOCA, is going to be different from a small LOCA, is
           going to be different from the best estimate LOCA, and
           so we need to think it through, and we don't have all
           of the answers yes.
                       DR. MEYER:  I know that Dana is concerned
           about some stressed that might be applied on the way
           up.  We have, in fact, focused more on the way down
           and have given more attention to the cool down part of
           this because this is when the oxygen and hydrogen and
           distributing themselves in the alpha phase and in the
           prior beta phase, and we believe that the cool down
           conditions are going to ultimately determine what the
           ductility is, and then you do the test when you're
           down at a relatively cold temperature.  You run it
           through the oxidation transient, come down, and then
           the ultimate challenge is near the end down at the low
                       So I know that you have for some time
           asked us to look carefully at the heat-up.  We've
           brought this question up.  We haven't found much there
           to accommodate.  You know, if there's something more
           specific that you can help us with, these conditions
           have not been set in concrete yet.
                       CHAIRMAN POWERS:  Yeah, my concern is that
           when we look at an individual rod in one of these
           scenarios, nearly always -- I can't say always, but
           frequently -- what you see is the rod heats up, then
           it cools down, and then it heats on up and hits the
           plateau, whatever it is.
                       On the average, if you plotted the core
           average, it looks like you ramp up to a plateau, sits
           in a plateau, and then it cools down, but by looking
           at the individual rod, it's actually going through a
           fairly complicated scenario, and it does have this
           cool down period, and it is, indeed, that cooling off
           that you become most concerned about.
                       DR. MEYER:  I think if it had a cool down
           period prior to the ultimate cool down and quench
           following a long period at a very high temperature,
           then you might have some interesting effects.  It was
           my impression that the ups and downs occurred at a
           relatively low temperature as you're approaching this
           high temperature period, and I don't think those would
           have a very big effect because you still have ductile
           cladding and a very small amount of the oxidation
           taking place.
                       We can continue to --
                       CHAIRMAN POWERS:  Well, I mean, when you
           do the tests, you're going to have to have some
           justification --
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  -- for that, I mean, and
           what you outlined is probably an appropriate
           justification, but it would have to be substantiated
           with something quantitative, the analysis.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  The heat-up that shows
           that all of these things are taking place at
           relatively low temperatures, and they don't go up, sit
           in a plateau, oxidize for a while, then cool down,
           then heat back up again. 
                       I think you'll find though --
                       DR. MEYER:  Sud Basu is the project
           manager for this program, and I'll at least say that
           we will go back to the project and tell them that
           we've been reminded of this again, and to make sure
           that we have either a justification for what we do or
           we change our says.
                       DR. SHACK:  I mean, I think if you look at
           it, you know, you're pumping all of this hydrogen in
           during this oxidation.  Then the tricky thing about
           this thing is as Ralph said.  You know, you don't
           really get the big thermal shock until you've cooled
           the thing down, in which case, you know, while this
           thing is hot, it's ductile as hell.  It's after you
           cool it down again that it re-embrittles, and then you
           hit it with the big thermal shock.
                       But the embrittlement that you get because
           you've pumped all of the hydrogen in because of all
           the oxidation that's occurred at the high temperature
           and the huge thermal shock that you finally get when
           this thing re-wets, you know, that really does seem to
           be the limiting material and stress condition that
           you're ever going to see.  You know, one of these
           cycles before you haven't pumped all of the hydrogen
           in.  You certainly haven't got a stress that's
           anything like the re-wet stress.
                       DR. MEYER:  Well, I mean, I understand the
                       DR. SHACK:  You're at the worst --
                       DR. MEYER:  But that's all I ever get is
           this argument, and I get other people showing me
           calculations and individual fuel rods that don't seem
           to be consistent with the argument, and nobody ever
           coming back to me and saying, "Look.  All right. 
           Here's the calculation we've done with our code that
           we're happy with, and here's how the fuel rods behave,
           and indeed, the limiting stress conditions are always
           calculated to be in the quenching."
                       I mean, you can wave your hands make
           those --
                       DR. SHACK:  Well, the stress and the
           limiting --
                       DR. MEYER:  You can make those arguments
           as long as you want to until you come back and
           quantitatively show me that that's, indeed, what you
           expect to be.
                       The problem with the old scenarios is when
           we were worried about just oxidation, then sitting at
           the high temperature plateau was the conservative
           case.  It's not clear now that we're worried about
           fuel embrittlement that sitting at the high
           temperature condition is the limiting case.
                       And how you get there suddenly become
           important, and making a qualitative argument all the
           time, I've heard it.  I agree it.  Now show me
           quantitatively that that's the case.
                       MR. NISSLEY:  Mitch Nissley, Westinghouse.
                       We've done a number of calculations with
           both evaluation model and realistic codes, and I would
           support the general conclusions that Ralph has
           offered, and we'd be more than willing to share that
           information with the staff to help resolve this issue.
                       I'd also say that some of the higher
           stress in the cladding during re-wet are really very
           early in re-wet at the bottom of the core where you've
           not had much oxidation.  It's the higher levels in the
           core generally we will have a slower cool down and a
           less severe quench load because there's a lot of
           precursor cooling as the reflood front progresses up
           through the core.
                       But we would be willing to provide
           quantitative information to the staff to help address
           this concern.
                       DR. KRESS:  Ralph, the research and the
           PIRTs deal with three design basis type of accidents. 
           Are you planning an additional PIRT to look at severe
           accidents and effects on the core melt behavior and
           fission product release?
                       DR. MEYER:  There's a PIRT that's been
           organized to look at source term, which is kind of
           serve accidents.
                       DR. KRESS:  Yeah.
                       DR. MEYER:  And I won't be running that
           directly, but Charlie Tinkler and Jason Shaperow, who
           have been involved with the severe accident program,
           will be conducting that PIRT.
                       DR. KRESS:  So questions about effects on
           high burnup on core melt and source terms will be
           addressed later.
                       DR. MEYER:  Yes.
                       DR. KRESS:  So it's not part of this.
                       DR. MEYER:  Yes.
                       DR. KRESS:  The other question I have is
           has anybody raised an issue of the potential effects
           of high burnup on the iodine spike and steam generator
           II rupture accidents?  Has that ever been brought up
           as a potential issue?
                       DR. MEYER:  I can't answer that question.
                       Jack, can you?
                       MR. ROSENTHAL:  Yeah, in response to the
           ACRS report, et cetera, we're just now planning out
           how to take on the iodine spiking issue.  So actually
           it's a very timely comment, and in my own mind you
           make so much iodine per fission, and it's a question
           of where is that iodine before the hypothesized event
           occurs.  Is it in the fuel or the gap, or is it
           already outside in the --
                       DR. KRESS:  I think that is very relevant.
                       MR. ROSENTHAL:  It is probably more
           dominant than the fact that at higher burnups you'll
           end up ultimately with some sort of equilibrium iodine
           concentration.  That is the time we have to take it
                       DR. KRESS:  Yeah.
                       MR. ROSENTHAL:  A different project.
                       DR. KRESS:  And also the spike is a rate
           at which things get out of clad, and that's not just
           a function of where the iodine is.  It's a function of
           what has happened to the clad.
                       So, you know, it could affect both of
           those things, but anyway, it's something I think ought
           to be thought about.
                       MR. ROSENTHAL:  Right.
                       DR. MEYER:  And finally, I just want to
           mention EPRI's cooperation in the big program at
           Argonne National Laboratory and to say to you that we
           finally have the H.B. Robinson fuel rods in a hot
                       So we have Odelli Ojer at EPRI to thank
           for a lot of hard work on that, and also John Siphers
           at CPNL in the end stepped in and was a big help.
                       So that's all I have right now.  I don't
           know if Med is -- we're really going to be pressed for
           time.  We have a 17 minute video on the Cabri program
           that Med might show at lunchtime.
                       CHAIRMAN POWERS:  Yeah, I think we're
           planning on doing that at lunchtime.
                       DR. MEYER:  Or some other time.
                       CHAIRMAN POWERS:  What I want to do now
           because I don't want to break up the next presentation
           is go ahead and take a 15 minute break now and we'll
           come back and listen to the presentation on the
           assessment of LOCA ductility of M5 cladding, and we
           can understand better the difference between quench
           and ring compression test.
                       DR. APOSTOLAKIS:  When are you going to
           show this video at lunch because I had other -- at the
           beginning, 12 o'clock or 12:30?
                       CHAIRMAN POWERS:  When I get around to it.
                                   (Whereupon, the foregoing matter went off
                       the record at 10:18 a.m. and went back on
                       the record at 10:33 a.m.)
                       CHAIRMAN POWERS:  Let's come back into
                       Ralph, I have TBD on my speaker for the
           Framatome testing assessment of LOCA ductility.
                       DR. MEYER:  Garry Garner will give the
                       CHAIRMAN POWERS:  Okay.  So it's actually
           Garry Garner is TBD.  Strange initials.
                       MR. GARNER:  If you like what you hear,
           it's  Garry Garner.  If not --
                       CHAIRMAN POWERS:  It's that other guy,
           right?  Good.  Good strategy.
                       MR. GARNER:  Well, good morning, gentlemen
           and ladies.  My name is Garry Garner.  I am a
           metallurgical engineer, materials engineer at
           Framatome ANP in Lynchburg, Virginia, and I will be
           speaking this morning of the LOCA ductility with M5
           clad testing results.
                       At the end of February, latter part of
           February, this presentation was given to the NRC
           staff.  We took about three hours and we had about 100
                       I've pared that down a little bit for this
           morning.  We had our in-house LOCA man give part of
           these results, and I gave primarily the mechanical
           test results at the end.  It's just me this morning. 
           I'll, of course, try to answer all of your questions. 
           If I don't know the answer, I'll defer, and we'll get
           it for you.
                       I want to stress at the beginning that our
           primary mission in life is not pure research.  Our
           goal with getting alloy M5 developed and licensed and
           in reactors is to do those tests that are required by
           the codes and the criteria and compare the results to
                       And you'll see, I hope, this morning that
           those results compare favorably or are the same in
           some cases.
                       The way I would like to proceed through
           this subject material is to start off with just a very
           brief review of a couple of things about in-reactor
           operating experience, not LOCA, but just normal in-
                       I want to talk a little bit about the
           alloy composition and fabrication parameters, and then
           I want to show you that it is a low oxidizing alloy
           and that it has a low hydrogen pick-up, and so I'll
           show you the oxidation curve and the hydrogen curve.
                       And then that is just as a way to set the
           table for the LOCA, post LOCA discussion that will
           follow, and we'll talk about the oxidation tests that
           we did, the quench tests, and the post quench
           mechanical testing, and then we'll follow with a brief
           conclusion and a summary.
                       So for the in-reactor performance, M5 is
           a binary alloy primarily of zirconium and niobium. 
           Tin is an impurity in this alloy.
                       Three things that might differentiate this
           particular Zirc-1 niobium alloy from an E110 or from
           someone else's zirc, one percent niobium are we do
           target iron in this 250 to 500 ppm range for improved
           corrosion.  Oxygen is targeted rather high.  The spec
           limit is 11 to 17.  We target it right in here for
           improved creep performance.
                       And sulfur.  Sulfur is an impurity.  It's
           not called out even in the spec as anything other than
           an impurity, but what we found -- and if you've kept
           up with the work of Mr. Sharke (phonetic) and others
           from Framatome -- we found that a very small change in
           an impurity element has a fairly dramatic change on
           macro properties like creep.
                       So when people talk about M5 being of a
           similar nature, similar chemistry to other alloys,
           yeah, on the surface, but on the other hand, very
           small changes can have very drastic effects.
                       Thermal mechanical processing also plays
           a role.  There's more to the alloy than just its
           chemistry.  This particular alloy is fully
           recrystallized, and in the tube making process and in
           the strip making process also, we do all of the
           intermediate temperature anneals below the transition,
           below the 610 transition.
                       DR. SHACK:  While we're at though, I mean,
           if the sulfur has such a big effect, why isn't it spec
           then rather than just left to float as an impurity?
                       MR. GARNER:  We found out sulfur, when we
           were developing the alloy during the creep tests, we
           were noticing that the thermal creep properties were
           all over the place with each ingot, and it turned out
           that some of the raw zircon coming from some of the
           beaches had an unnaturally higher sulfur content than
           the others, and some of them were low.
                       So we did the research.  We found out
           where the knee in the curve was, and now we specify
           ten to 35 ppm sulfur in our spec.
                       By the way, we also found that same effect
           for Zirc-4 to a lesser degree, but I think all of the
           zirconium alloys are sensitive to that.
                       So just to make sure that we always get
           the right creep properties, the good creep properties,
           the best thermal creep properties that we can get, we
           do specify it now between ten and 35.  But you won't
           find that in the ASTM zirc specs.
                       Again, my point on the mechanical
           processing, we do the anneals below the transition. 
           We found with this alloy that that makes a marked and
           significant difference in the microstructure, the
           appearance of the microstructure, and the stability of
           the microstructure of the alloy.
                       If we can go into a LOCA and a post LOCA
           with the stablest microstructure possible, that's what
           we want.  So it's not only a stable microstructure and
           a good chemistry.  It's not only important in the
           normal operation.  It's important in an accident
           condition as well.
                       The two properties that I would highlight
           this morning are the corrosion, and you've seen these
           kind of curves before.  This curve -- and I apologize. 
           It's hard to read because it is just so small on this
           viewgraph -- but it's the maximum oxide thickness
           versus fuel rod average burnup, and you can see that
           all of the colored dots are M5 data points.  They come
           from a wide variety of reactors, from 14-14 to 17 by
           17, and the colors are just differentiating those.
                       And there is a linear behavior up to a
           burnup so far of 63 gigawatt days.  This is sort of
           the line through the middle of the Zirc-4 data.
                       The points that I would make here is that
           we're getting more and more additional data in the 50
           to 60 gigawatt area.  We're seeing no increase in the
           oxidation rate at the higher burnups.  The highest
           oxidation so far has been about 40 microns at 60, 63.
                       So it is a low oxidizing reactor, and
           that's important when we start talking about what's
           the condition of the alloy, when you go into an
           accident condition.
                       CHAIRMAN POWERS:  If I look at the data
           points from the 16 by 16 --
                       MR. GARNER:  Yeah, the red ones.
                       CHAIRMAN POWERS:  It looks to me like you
           could probably convinced yourself as you went out
           toward 60 you would get the same kind of upturn that
           you see for Zircaloy-4 based on those data points.
                       MR. GARNER:  I don't really think so. 
           These reactors are different duties, granted.  There
           does seem to be a little bit higher effect in the 16
           by 16s.  I think the behavior still though is rather
           linear.  I don't see any kind of a two slope upturn
           like you do see with the Zirc-4 type alloys.
                       Yeah, when we get more data out here for
           16 by 16s, we'll see what that's doing, but so far I
           would point out that the max oxide there is 41
           microns, and only in that point.
                       So if it does turn up, it's going to turn
           up at a significantly different rate than these guys
           are turning up.  Hopefully.
                       Similarly, the hydrogen plot for these
           alloys, I had hoped to have because the results are
           going to be given to us in April, some burnups in the
           mid-50s to almost 60 or right in here, to show you
           that this linear trend with M5 continues, but you have
           the hydrogen content MPPM versus fuel rod average
           burnup here, and there's the Zirc-4.
                       As you would expect, the source of most of
           the hydrogen for these alloys to pick up is the metal
           water reaction that's going on.  So you would expect
           a similar kind of behavior.  This alloy has a
           significantly lower pickup fraction than does Zirc-4,
           and so we get a flat behavior.
                       Again, this is going to get important when
           we talk about how much hydrogen is in the alloy in the
           event of the LOCA, either at the beginning, middle or
           end of life.
                       As you can see on this curve, it's going
           to be less than 100 if this trend continues out here
           as we expect it, of course, to do beyond 60 gigawatt
                       So just a summary for just  that brief
           portion of this presentation.  It is a low oxidizing
           alloy.  We don't see any increase in the oxidation
           rate at the highest burnups that we've achieved, which
           are 63 gigawatt days.
                       If the alloy is lower in sensitivity, to
           temperature and rod power, we've seen that it has
           less, dramatically less response to those kind of duty
           factors, temperature and power, than do the Zirc-4
                       The low oxidation rate and the low
           hydrogen absorption, the low hydrogen pickup fraction
           for this alloy end up with a low hydrogen content at
           high burnups, end of life burnups.
                       DR. CRONENBERG:  When did M5 go into use? 
                       MR. GARNER:  Yeah, it went into just rod
           by rod demonstration rods in the early '90s.  It went
           into our first batch deliveries were in '98, full
           batch reloads, and now we're well on the way of
           delivering those full batches now.
                       DR. CRONENBERG:  And that's all in France?
                       MR. GARNER:  No, no, no, no.  We have full
           batches at  North Anna and Oconee at this point and
           some more being delivered later this year.
                       Our North Anna reactor burnup is after --
           we just finished our second cycle, and we're on our
           lead assemblies there, and our burnup was 40 to 46
                       MR. ALDRICH:  Mike Aldrich in Framatome.
                       I think right around 46 peak rod.
                       MR. GARNER:  I think it was 46, 300 peak
           rod of gigawatt days.  So, yeah, we do have it in the
           -- the alloys in TMI, North Anna, Oconee.
                       MR. ALDRICH:  Yeah, the full batches that
           we have are at Davis-Besse, Oconee Unit 1.  We're
           supplying Oconee Unit 2 right now, and at TMI will
           also be getting a batch this fall.
                       DR. CRONENBERG:  And then for the hydrogen
           pickup, you take them back to Lynchburg and do your
           constructive testing there or --
                       MR. GARNER:  I didn't mean to mislead you
           on that.  We haven't done a hot cell within the U.S.
           M5 yet.  Those are planned.
                       These hydrogen analysis were done from the
           European exposures, yeah.
                       Okay.  Now, I would talk about the results
           in the high temperature testing, the oxidation quench
           test and post mechanical quench test.  It was called
           the CINOG.  That was the facility in Grenoble where
           the work was done, and beyond that I don't even know
           what CINOG means.
                       The test matrix for the high temperature
           oxidation tests were we tested both M5 and Zirc-4.  It
           was a double sided oxidation experiment.  Length of
           the samples, about 20 millimeters.
                       We tested as manufactured, unradiated
           cladding, just as received from the cladding from the
           tube vendor, at temperatures between 700 and 1,400 C.
                       At 1,200 C. we tested some pre-hydrided
           cladding, which was pre-hydrided at 200 ppm for the M5
           alloy and 200 and 450 ppm for Zirc-4.  The reason that
           we didn't go to the 450 for M5 is for the obvious
           reason that we're not even going to get 200 possible
           in normal behavior, plus the oxidation.  We're going
           to show you that in a few minutes.  We're not going to
           get so -- 200 was felt to be very bounding for M5.
                       We did three oxidation times at each test
           temperature.  To try to get these, you know, you time
           it, and you try to get 50, 100, and 200 microns per
           side, and for three samples for each test conditions
           we're done.
                       The results of the oxidation testing are
           presented on this plot.  It's a little bit busy, but
           really the results aren't as busy as it might seem.
                       On the left is oxide in terms of weight
           gain, milligrams per centimeter squared, versus the
           oxidation times square root of seconds, and you'll see
           a series of lines here.  
                       For instance, in like I say it was 700 to
           1,400.  At 1,400, Zirc-4 and M5 oxidation kinetics are
           right on top of each other.  If you had the time and
           inclination to go through this legend, you'll see that
           at that temperature they're the same.  At 1,250
           they're the same.  At 1,150 they're they same.  At
           1,100 they're the same.
                       At 1,050 the Zirc-4 and the M5 are parting
           company rather dramatically with the M5 having a much
           lower oxidation kinetic than the Zirc-4.
                       Now, I didn't draw lines through the data,
           but the NFI did some independent research  on our
           alloy, on M5, and got the same results, and that's
           what you see right here.  The open triangles are Zirc-
           4, and the closed triangles are M5.  So, again, you're
           seeing that behavior.
                       Mr. Lebourhis at the OECD meeting two
           weeks ago in France presented the results on this
           curve of another French test at 1,000 degrees saying
           the same thing.
                       And then down here at 900 again, the
           alloys are having the same oxidation kinetic again,
           900, 800, and 700.  So this area here between 1,100
           and 1,050, lower than 1,100 and greater than 900, the
           M5 alloy is clearly oxidizing at a lower rate.  It's
           the only place in that spectrum that that's happen.
                       I put the 17 percent for folks that want
           to think about weight gain in terms of the ECR, the
           equivalent clad reacted.  It's right in there, about
           24, 25 milligrams per centimeter squared.  So that's
           about 17 percent ECR.
                       You can see that we behave better or
           similar to Zirc-4 at these temperatures.  The values
           are consistent with the literature, and they were
           verified by independent folks, NFI in this case.
                       CHAIRMAN POWERS:  Do you know why you're
           slow in the oxidations in the 1,050 to 1,100 degree
                       MR. GARNER:  I don't, no.
                       CHAIRMAN POWERS:  There's a phase
           transition in there someplace, isn't there?
                       MR. GARNER:  Yes, yes.  You know, and the
           alloy -- we know that the chemistry of the alloy has
           to do with what temperature that phase transition goes
           in and like that.  That's certainly the speculation,
           but I'm not an expert on that.  I don't know exactly
           why that is, but it's very well documented, and it is
                       DR. CRONENBERG:  Do you have the
           diffusivity measurements at these temperatures, too,
           that for the two different alloys, oxygen diffusivity
                       MR. GARNER:  We did not make diffusivity
           measurements, no.
                       DR. CRONENBERG:  Is there in the
           literature that show that, yeah, this is all in sync,
           that there's a phase change, there's a diffusivity
           change, therefore, there's an oxidation rate change?
                       MR. GARNER:  Right.
                       DR. CRONENBERG:  I mean, is that all --
                       MR. GARNER:  It's all consistent.
                       DR. CRONENBERG:  It's all consistent?
                       MR. GARNER:  Yes, sir, yeah.
                       Okay.  In those results compared with
           literature results, compared with the correlations,
           this is the weight gain function again, and in this
           case one over the reciprocal of temperature.  So
           temperature is going down as you go this way.
                       We've plotted the Baker-Just correlation
           with the solid line.  The dotted line is the Leistikov
           correlation, and the points here are the M5 and Zirc-
           4.  The open squares are Zirc-4.  The solid, the
           diamonds are M5, and you can see at the higher
           temperatures that the data are consistent with each
           other, and also shows that Leistikov does a fair job
           of predicting actual data, whereas were conservative
           to Baker-Just.
                       At this lower temperature, and this
           corresponds to about 1,300 degrees C., you see that
           difference again where M5 and Zirc-4 are behaving
           differently, and with the lower oxidation kinetic
           associated with M5.
                       So we are bounded by Baker-Just in all the
           encountered configurations, and I think we were
           surprised that Leistikov does a fairly good job of
           predicting the real data.
                       DR. CRONENBERG:  Prater-Cartwright was
           used during -- developed during severe accident
           program here for Zirc-4.  Have you benchmarked
           anything against Prater-Cartwright for severe accident
           conditions with the M5 class?
                       MR. GARNER:  We did have a slide in the
           presentation at the end of February where we showed
           consistency with the Prater-Cartwright data, yes, and
           I can --
                       DR. CRONENBERG:  It's less?
                       MR. GARNER:  Yes.
                       DR. CRONENBERG:  Your data is less than
           what would be predicted by Prater-Cartwright?
                       MR. GARNER:  Yes.
                       DR. CRONENBERG:  Okay.
                       MR. GARNER:  Now, in terms of what we
           saw --
                       CHAIRMAN POWERS:  Radiation has no impact
           on these?
                       MR. GARNER:  Excuse me?
                       CHAIRMAN POWERS:  Radiation has no impact
           on these oxidation rates?
                       MR. GARNER:  I think radiation can be
           expected to have a small impact on them, yes.
                       When we looked at the oxide coming from
           these oxidation tests, at the high time, 1,000
           degrees, these were two sided tests, and so in this
           picture you see the oxide, the base metal to both the
           alpha and the prior beta, and then the inner layer
           oxide.  This is the mounting, the medium here.
                       And you see for Zirc-4 that you do have
           this layer, this flakiness, this layering.  It's a
           trace amount of it, but it is present, and we saw that
           on both the inner layer and the outer layer of the
           Zirc-4 samples.
                       When we looked at the M5 alloy, same
           magnification, you see the less oxide here in this
           case.  This is the mounting material.  This is the
           base metal, and where all of the etching in these
           photographs to see the oxide and any flaking.
                       You see that it is a less, but the
           important thing is that there is a homogenous barrier
           there.  There are no cracks through it.  There are no
           -- none of these delaminations through it that we saw
           a slight bit of in Zirc-4 that you're going to see a
           whole lot more of in the E110 in a few moments.  So we
           didn't see that.
                       Now, just to put some numbers to these
           pictures, I thought it might be interesting if on the
           two sided test you have the external zirconium layer,
           the external oxide, the internal oxide, and then you
           have the oxygen stabilized alphas next to both of
           those, and then in the middle the beta layer.
                       And for Zirc-4 you can see the expected
           difference in the thickness of the oxides, both on the
           inner and the outer, but you can see that the alphas
           and the beta phase are about the same.
                       This is interesting because in other
           results for Zirc-niobium alloys, and specifically the
           Bohmert paper, he explains in there that he had a hard
           time differentiating the alpha and the beta, and he
           couldn't find it.
                       In a picture that I'll show you in a
           little bit you can sort of see what he's talking about
                       In this alloy and you'll see it in some
           other pictures in a little while, those layers are
           very discernable, and you'll see that in a minute.  So
           those numbers sort of just go with those pictures. 
           That's the magnitude of the thicknesses involved
                       Now, the quench test, the quench test
           matrix, again, comparing M5 and Zirc-4, double sided
           oxidation test.  Failure was defined as if you put a
           slight after the quench, if you put a slight over
           pressure in that and you see some bubbles coming out;
           that's failure.  It's a fairly conservative definition
           for failure because just a pin hole is a failure under
           this criteria.
                       The temperatures tested at were 1,000
           through 1,300 degrees C. in 100 degree increments. 
           Again, as manufactured tubing.
                       At 1,200 degrees C., again, the pre-
           hydrided samples, 200 ppm for M5 and the higher ppm
           added for Zirc-4, and generally you did five or more
           tests to establish where that failure occurs.  You
           test until you get that failure, and so generally that
           took five or more times.
                       And then there was post test metallography
           and hydrogen analysis, which I can show you.  The
           results, just in a nutshell, on this plot you can see
           that the two alloys in this column, that the
           temperatures 11, 12 through 13 and the time to
           failure, and you can see at these higher temperatures
           they're fairly consistent, the two alloys.
                       At the lower temperature, the 1,000
           degrees, the M5, it took twice as long to fail,a nd
           you'll see this again on the curve in a moment.
                       For events of equal duration, alloy M5
           seems to be superior to the Zirc-4.  
                       Plotting that up as a function of ECR, we
           have ECR on the left and temperature on the bottom
           here.  This is the Baker-Just correlation points.  I
           hope nobody asks me why that dips because I sure don't
           know.  It surprises us.
                       This is the Leistokov correlation points,
           lower understandably, and uniformly.  And then this is
           our data.  We're plotting failure points up here, and
           as you can see, at the 1,300 degrees temperature, the
           red line is the 17 percent linking the criterion, and
           so that's a failure point at 1,000 degrees, and it
           took four and a half hours to get there.
                       And this is the last unfailed point, and
           it took three and three quarters hours.  So somewhere
           between three and three quarters hours and four and a
           half you fail this alloy, and it looks like it's
           pretty close to the 17 percent criterion.
                       It's really for this kind of reason that
           we think that 17 percent criterion is a decent
           criterion for this alloy, because it's of no concern
           until you get to times of failure that are just so
           ridiculously large that it's no longer interesting.
                       We measured the hydrogen content for the
           two alloys.  Zirc-4, at these oxidation temperatures,
           this was, again, the durations of these tests, and you
           can see that the hydrogen content here -- these are
           the results of three different measurements, and you
           can see that they're in the 20s, and they're fairly
           consistent.  M5 might be just a tad lower.  It's not
                       The significance of this chart to me is in
           some of the Eastern European papers, specifically
           Bohmert again, at 1,100 degrees where we're showing 18
           to 20 ppm of hydrogen in our oxidation and quench
           test, that study produced over 400 ppm of hydrogen. 
           Don't know why.
                       So the results, just a summary of the
           results.  The oxidation and the quench.  It's clear
           that M5 is performing equivalent or superior to Zirc-
           4.  The hydrogen uptake is low.  That's clear.
                       The M5 accident survival is definitely
           superior to Zirc-4.  At temperatures greater than
           1,100 they're about -- they're the same.  At
           temperatures less than 1,100, it's surviving up to two
           times longer than Zirc-4.  That's consistent with
           those oxidation curves and that small band of
           temperatures where M5 has the greater oxidation
                       The oxide itself in the quench  and in the
           oxidation, it's not delaminating.  It's not showing
           any signs of breaking down.  It's not cracked or
                       If you use Baker-Just to establish the
           criteria, of course, M5 always meets it.  We do
           successive  oxidation times to achieve -- if you want
           to get down to 17 percent criterion, it takes a long,
           long time to get there with a low oxidizing alloy, and
           again, we agree with the criterion.
                       Now, in our efforts to license this with
           the utilities and the power authorities in Germany,
           they are very aware of the Bohmert paper, and they
           wanted to see how we did in post quench mechanical
           testing similar to what he did, and so a year and a
           half, two years ago, Framatome undertook to do some of
           those tests.
                       This was the test matrix.  We tested at
           1,100 degrees C.  We did it for times that would give
           ECRs from three to 17 percent.  This series of tests
           was a single face oxidation, and again, we used as
           fabricated M5 and compared it to Zirc-4 cladding.
                       After oxidation it was water quenched, at
           which point we did mechanical tests.  We did a three
           point bend test, an impact test, and split ring
           compression test.
                       That begs the question.  That matrix begs
           the question:  why did you test at 1,100 degrees? 
           And, again, we go back to this chart.  We wanted to
           test in an area where the alloys of M5 and Zirc-4 are
           oxidizing at a similar rate.
                       It's not very interesting down here to
           test M5 because it takes so long to get anywhere close
           to 17 percent.  It's really out of the realm of what
           we're interested in.  So we picked 1,100 degrees,
           where the two alloys are oxidizing at a fairly steep
           rate, and they're oxidizing the same.  A test in that
           region might learn something was the thought.
                       This just briefly was the test rig that we
           used for that series of tests.  It's just a four zone
           heater with the sample hanging here.  This is the
           little quench tank.  The reason I wanted to show this
           slide is mainly for that little piece of white cotton
           that's sitting in there.  That collects the oxide that
           falls off of the sample upon quenching, and we wanted
           to show you the results of that.
                       So each sample, that oxide was collected
           and weighed and compared to the weight gain that that
           sample achieved in its oxidation phase.
                       DR. CRONENBERG:  Were you measuring any
           hydrogen off-gassing besides hydrogen pickup?
                       MR. GARNER:  No.
                       DR. CRONENBERG:  No?
                       MR. GARNER:  No.
                       And here are the results of those tests. 
           At 1,100 degrees Centigrade, again, for the longest
           exposure times, the Zirc-4, these were the weight
           gains observed, and that was the oxide spalled in
           grams, and this is expressed as a percentage of the
           weight gain.
                       And you can see that with the Zirc-4
           because of that slight delamination that we saw, that
           slight flakiness in that alloy, it's losing a lot on
           quenching.  It's losing between 65 and 80-some odd
           percent of its oxide, whereas the M5 oxide seems to be
           very tenacious.  It's losing only between two and four
                       That confirms quantitatively what those
           pictures were attempting to show qualitatively about
           the difference in the character of the oxide in M5 and
                       Now, the pictures, again, also support
           those results.  This is the Zirc-4 at the high time. 
           On this sample you can see clearly the oxide layer,
           the alpha layer, the oxygen stabilized alpha layer,
           and the prior beta, and you see the large greens.
                       In this picture, and you can see it a
           little bit here, but more in this picture that was
           etched specifically to bring this feature out, the
           oxide is up here and you can't really see it, but this
           is this alpha area here, and you can see these cracks. 
           That oxide is cracking, and it's breaking down, and
           that explains the results that we just saw.
                       Now, in contrast to that, the M5 oxide
           looks like this.  Again, it's the same kind of
           picture.  There's the oxide, and then there's the
           alpha, and then the beta below that, and again, over
           here you can't see the oxide, but you can see this
           alpha area.
                       And I guess you have to take my word for
           it a little bit.  Those are not cracks.  They're
           shadows.  Most of what they are is this linear
           distribution of niobium particles.
                       At these temperatures, what we noticed,
           and you can see it here, within the matrix of the
           grains, you see the particles lining up in a linear
           fashion.  That's a microstructure that we specifically
           prohibit in the alloy for a normal operation, but in
           a LOCA event, that's what happens.
                       When you go above that oxygen or alpha-
           beta transition, you tend to get that, and that's
           what's going on these, these agglomerations of beta
           Zirc or beta niobium sitting there.
                       Again, no cracks, and again, you get that
           linear distribution.
                       Now, to compare that with what people have
           observed in some of E110 alloys, this is a picture
           that was not in Mr. Bohmert's paper.  It is in a
           Russian report, and I can give you the reference of
           that if you need that, and in a second, I'm going to
           show you a quote from Mr. Bohmert's paper where he
           describes in words what he's seeing here, and other
           folks have seen this, too.
                       Again, the stratified oxide, in this case
           highly stratified.  In the Zirc-4 that we looked at a
           little while ago, it typically had, you know, one of
           those going through there.  This alloy is full of
                       Mr. Bohmert also makes the point that he
           can't find what's going on in the base metal between
           alpha and beta.  This picture, although probably not
           optimally etched for that, tends to support that.
                       The point here is that it's a very
           stratified and cracked oxide layer, and it has a
           completely different morphology than M5.  In words,
           Mr. Bohmert said that not at a late stage -- that
           photograph that I just showed you was taken after like
           9,000 seconds -- but Mr. Bohmert and his work said
           that at an early stage he found the same thing in
           multi-layer oxide scales formed which tend to flake. 
           We saw that flakiness in the Zirc-4.
                       And, again, we just didn't see that.  We
           don't see it in M5.  We've never seen that kind of a
           morphology, and in the quench test, you can see that
           when we weighed the amount of oxide that's falling
           off, falling off, flaking off, it's not there.
                       DR. CRONENBERG:  I think 110 has higher
           niobium and higher tin or --
                       MR. GARNER:  I'm going to say that I don't
           know.  Nominally it's the same niobium.  Nominally
           it's a Zirc one percent.
                       DR. CRONENBERG:  I thought it was like two
                       MR. GARNER:  No.
                       DR. CRONENBERG:  No?
                       MR. GARNER:  There are alloys that are
           two, two and a half, and even Framatome has fooled
           with those from time to time.  E110 is nominal one
           percent, but as far as their tin, their impurities,
           their other things, I don't know, and I specifically
           don't know with respect to the version of E110 that
           Mr. Bohmert tested back in the early '90s.  It could
           be vastly different from the E110 that's in reactors
           now for all we know.
                       DR. CRONENBERG:  Did he put in his paper
           what the --
                       MR. GARNER:  He put the chemistry in
           there.  Yeah, and like I say, it's a nominal one
                       DR. CRONENBERG:  Do they use the one
           percent now or is it two percent?
                       MR. GARNER:  They use the one percent.
                       Post quench mechanical tests, the three
           point bend test was the first one that was done.  This
           is just a picture of the test rig showing the two
           mandrels with about a nine millimeter rod, tube going
           through there and pushing down on the center of it.
                       The maximum deflection that they got on
           all of these was about seven and a half millimeter
           displacement off of that line.  That's the rig.  Did
           it for M5 and Zirc-4, and that's the results.
                       And you can see that the Zirc-4 and the M5
           in this case are right on top of each other in terms
           of the displacement versus weight gain.  They are
           behaving similarly in three point bend tests.
                       The next test was an impact test.  I don't
           have a picture of the test rig for that, but it was
           like any impact test.  It was a tube made with a notch
           and a hammer coming down, and you're measuring the
           energy that's absorbed in the material here called
           resilience joules per square centimeter, again, versus
           weight gain, and you can see again the two alloys, M5
           and Zirc-4 behaving very similarly.
                       When you look at the fracture surface like
           you like to do it with impact tests, you notice that
           the Zirc-4 was a ductile ruptured in the ex-alpha-beta
           phase and brittle in the oxygen alpha.  M5 was
           essentially the same, just a tad more ductility. 
           Maybe that explains that in the alpha phase.
                       DR. SHACK:  Now, if you did a sort of
           typical LOCA transient, what would your expected
           weight gain be?
                       MR. GARNER:  A LOCA transient.  
                       DR. SHACK:  Just to calibrate myself on
           this curve.
                       MR. GARNER:  Yeah.  Well --
                       DR. SHACK:  It would be less than 17
                       MR. GARNER:  Yeah.  What we saw in one of
           these curves back here a minute ago, the weight gain
           for 17 percent is about 24 milligrams per square
           centimeter.  So on that curve you could see where we
           would be relative to that.
                       DR. SHACK:  Okay.
                       MR. GARNER:  Yeah.
                       DR. CRONENBERG:  Well, then what's going
           on between the E110 and the M5 if it's not
           composition?  Was it --
                       MR. GARNER:  I didn't say it wasn't
                       DR. CRONENBERG:  Okay.
                       MR. GARNER:  In fact, I tried to imply
           just the opposite of that.  The compositions are
           nominally the same, but what we found out in the
           development of M5 was very small changes can have very
           large effects.  So it might be something like that. 
           There might be a compositional --
                       DR. CRONENBERG:  And it's not in the
           annealing process.  So --
                       MR. GARNER:  It could very well be.  If
           you don't anneal below the alpha-beta transition, you
           will not get a stable microstructure.  One of our
           developmental precursors to M5 was we called it 5R,
           and we even put it in test rods in reactors, and it
           didn't do as well as M5 does, and that's when we made
           the change.
                       What we were doing with 5R was we liked to
           anneal above that transition because we got better
           creep properties.  What we found out was that that had
           detrimental effects on some of the local oxidation,
           specifically oxidations under spacer grids and like
                       DR. CRONENBERG:  But it's also time and
           temperature for annealing and so it's not sorted out
           then.  You said you think it's probably chemistry and
                       MR. GARNER:  All we can speculate is it
           has to do with the stability of the microstructure. 
           Beyond that I wouldn't care to speculate because,
           number one, I don't know much about E110.  It's not
           our position in life to compare our alloy to E110. 
           We're trying to compare it to Zirc-4.
                       Sure, we're as interested and curious as
           anybody as to why these differences might be, but
           we've not done any testing on E110.  We read what we
           can read.
                       What we do know from our own experience is
           the target of some of these even impurity level
           chemistry have large effects.  We know from our own
           experience that the thermal-mechanical processing at
           the tube manufacturer is extremely critical to the
           stability of the microstructure and in areas of
           corrosion specifically.  
                       That's why we went from 5R to M5.  That 5R
           microstructure that I was telling you about that has
           those banded beta niobium particles, M5's
           microstructure is uniform and stable under
           irradiation, and that's all a function of that
           intermediate annealing temperature.
                       So I wouldn't say that those two things
           don't have something to do with the differences that
           we see in E110, but I'm not an expert on E110, and I
           don't want to stand up here and talk about it as if I
                       DR. CRONENBERG:  But M5 is not used for
           any guide tubes or --
                       MR. GARNER:  Yes, it is.
                       DR. CRONENBERG:  Oh, it is?
                       MR. GARNER:  Yes.  We use it for guide
           tubes, and we have our first spacer grids in lead test
           assemblies hit Davis-Besse right now.  So our intent
           is to have an all M5 assembly very, very soon.
                       DR. CRONENBERG:  So are you going to show
           us the irradiation growth properties of M5?
                       MR. GARNER:  I could.  It wasn't part of
           this presentation.
                       DR. CRONENBERG:  I was thinking of the

           small rod problems that we --
                       MR. GARNER:  Right, right.
                       MR. ALDRICH:  So far the -- this is Mike
           Aldrich, Framatome again -- the growth data from the
           guide tube material at North Anna and the LTAs that
           Garry was referring to earlier at the peak rod burnup
           of 46,000 we've seen virtually no growth of the guide
           tube material at all.
                       MR. GARNER:  It's not that much different
           than the Zirc-4 and that's because the Zirc-4 guide
           tubes are also fully recrystallized.  So that growth
           function, it's not just totally dependent on the
           recrystallized versus SRA nature, but it's primarily
           driven by the structure of the alloy.  Recrystallized
           alloys have a lot less growth than do stress relief in
           annealed alloys, and that's why the M5 guide tubes,
           they do grow a little less for other reason, but just
           a little less.
                       DR. SHACK:  The mechanical tests we're
           looking at were all done in a single heat of material?
                       MR. GARNER:  Yes, yes.  Those tubes were
           provided from a single lot at the tube vendor.
                       DR. SHACK:  And how do you then set the
           spec on, say, the iron limits?  Is it you're checking
           the microstructures, that over that fully range -- you
           know, how do you test the stability of your
           microstructure, since that seems to be your argument?
                       MR. GARNER:  Right.  Lots and lots of
           tests there.  We did a lot of test reactor testing, a
           lot of out-of-pile testing, autoclaves and things like
                       Every time we tweak something like a
           sulfur, like an iron, we went through that whole gamut 
           We wanted to be sure that we weren't buying ourselves
           some creep property or some growth property or some
           corrosion property at the expense of something else.
                       So there's an extensive test base behind
           those targets for all of those constituents, yeah, and
           it's a tradeoff.  I mean, when you don't have tin in
           your alloy, you have to get creep properties from
           somewhere else, and in our case, we've done it with
           oxygen, and we've controlled it and controlled its 
           uniformity with sulfur and these other things, iron.
                       So, yeah, that was the whole trick with
           this alloy.  People knew years and years ago that
           corrosion was going to be good with a niobium alloy. 
           The trick was how do you get there and still have
           these other properties.
                       Those ranges were set after lots of
           testing.  The last mechanical test --
                       DR. CRONENBERG:  What this tells me is
           that it has to be a go slow process when you're
           talking about these sort of things.  When you have
           small changes in composition it can affect different
           properties in different ways, and so we had had
           surprises like control rod insertion problems.
                       MR. GARNER:  Right.
                       DR. CRONENBERG:  The bending of guide
           tubes, the irradiation growth, things like that, and
           so that's just a general statement.
                       You're also saying that small changes in
           composition can give you a surprise change in
           mechanical performance.
                       MR. GARNER:  You bet you, and like I said,
           the development -- and we agree with you -- the
           development of the alloy was a slow go, and we went
           through many iterations before we got to M5.  Now all
           of those properties are controlled so that one reactor
           doesn't get one iron in one oxygen and another guy get
           another sulfur.  Those are all controlled in our
           specification as you would control these things with
           any alloy in any specification.
                       The development of those ranges was slow
           go, and now we insure the properties like every vendor
           insures its properties, with its spec.  And we agree.
                       MR. ALDRICH:  I might also add, if you
           were through.
                       MR. GARNER:  Oh, yes, sir.
                       MR. ALDRICH:  As far as the deployment of
           the alloy and the fuel surveillance section of the SER
           for M5, we are required to take additional PIE data of
           things like you're referring to, control rod
           insertability, as the burnup of the fuel in reactor
           exceeds higher and higher levels up to the license
           limit, we are required to take PIE data.  So that type
           of performance would be verified.
                       MR. GARNER:  We do take an awful lot of
           PIE data.
                       The last post quench mechanical test that
           we did was the ring compression test.  Again, that's
           just the rig, and you can see the sample sitting in
           there waiting to be pushed on.  And again, the similar
           results with Zirc-4, displacement versus weight gain. 
           The alloys are the same.
                       DR. SHACK:  I mean when I look at these
           things, is this really telling me that if I pump the
           sort of same amount of oxygen and hydrogen into these
           alloys, they act about the same?
                       MR. GARNER:  Yes.
                       DR. SHACK:  And the difference really is
           the rate at which you pump hydrogen into it because of
           the corrosion properties.  When you look at these
           things, you sort of see the same thickness of the
           stabilized layers --
                       MR. GARNER:  Yes.
                       DR. SHACK:  -- for a given weight gain?
                       MR. GARNER:  For a given weight gain we
           do, and that was different than some folks have seen
           with other Zirc 1-niobium alloys.  We do, and I wanted
           to show on that one chart that our oxygen stabilized
           alpha and our retained beta were almost identical to
           that of Zirc-4.
                       Now, the reason we're here is Bohmert, and
           so we plotted our ring compression tests against the
           same variables that he did, the relative deformation
           on the left, ECR value across the bottom.
                       The black line here is sort of the line
           through his data, which showed the embrittlement at
           the lower temperatures.  This is the line below which
           you consider the allow brittle.  Above 65 you can
           consider it ductile, and in the middle it's mixed.
                       What you can see here with the blue, the
           solid blue, the squares and the open blue squares --
           the solids are our results for Zirc-4.  The opens are
           Mr. Bohmert's results for Zirc-4, and you can see that
           by and large, with the exception of maybe that point,
           we agreed.  This told us that his work was probably
           pretty good, and he had pretty good control over all
           of his test parameters because when we tested an alloy
           that we know was like the alloy that we tested, we got
           pretty much the same results.
                       Where we differed was where we compared
           his Zirc 1-niobium, which was the alloy E110 of 1992
           vintage to our M5, and as you can see, our M5 is right
           along on the same curve as the Zirc-4, which our other
           data has supported, and where we differed was that's
           where E110 came in at 1,100 degrees.
                       We don't have any inherent quarrel with
           Mr. Bohmert's work.  What we know is that the alloys
           M5 and that E110 that he tested are apparently very
           different, and I tried to show you this morning that
           they're different in terms of the results that we get,
           the measurements on the mechanical tests, the
           measurements and the oxides, the oxidation rates, and
           even what they look like, the morphology of the
                       These two alloys, while nominally Zirc one
           percent --
                       DR. CRONENBERG:  They are not the same.
                       MR. GARNER:  -- they are not the same, and
           that's what I showed you.
                       Now, I haven't got the data to win the
           Nobel Prize yet on why, but they're clearly two
           different alloys.
                       So just to conclude just a summary of the
           post quench mechanical test, we tested in the Bohmert
           range.  We tested at that 1,100 degrees temperature
           and for the reasons that I tried to explain.  That's
           where the two alloys, Zirc-4 and M5, are oxidizing at
           the same rate so that you can see what's really going
           on there with those guys.
                       We have an order of magnitude less
           hydrogen uptake than Mr. Bohmert's 110.  He was
           getting 400 at 1,100 degrees.  We got 20, and I've
           showed you that we had a completely different oxide
                       And we had no delaminations in our oxide,
           in our mechanical test.  We had similar bend test,
           similar impact test, similar ring compression test to
           Zirc-4, significantly better than E110.
                       We agree with Mr. Bohmert's conclusions
           regarding the Zirc-4, significant different results
           though in the two different alloys that we've tested,
           his E110 and our M5.
                       Now, just one last slide to summarize the
           entire high temperature, oxidation, quench, post
           quench mechanical test results.  I hope that I've
           demonstrated this morning that the M5 in reactor
           operating performance is clearly superior to the Zirc-
           4; that our LOCA/post LOCA oxidation rates are equal
           to or a little bit slower than Zirc-4 and
           significantly slower in certain temperature ranges.
                       Our LOCA/post LOCA mechanical performance
           is equivalent to Zirc-4 essentially.  
                       The performance is acceptable and is equal
           to or better than Zirc-4 of events of equal duration. 
           For a low oxide it takes an awful long time to get to
           17 percent ECR.  If you had the ultimately perfectly
           alloy that didn't oxidize at all, you'd never get
           there.  So some consideration of time has to be taken
           into consideration, and I think everybody does, and
           that's why we agree that the 17 percent criterion is
           valid, if you consider how long it takes to do that.
                       And, again, with respect to the E110
           alloy, our data is completely different.
                       So that concludes that I had to say.
                       CHAIRMAN POWERS:  Thank you.
                       Any other comments for the speaker?
                       Ralph, do we know more about this E110? 
           We're going to learn more about E110.
                       DR. MEYER:  In the presentation that I
           plan to summarize the meeting that we went to, I have
           further information on E110 --
                       CHAIRMAN POWERS:  Okay.
                       DR. MEYER:  -- from other laboratories as
                       CHAIRMAN POWERS:  Okay.
                       DR. MEYER:  And I'll give you what I have.
                       CHAIRMAN POWERS:  Good, good.  Well, thank
                       MR. GARNER:  Thank you.
                       CHAIRMAN POWERS:  The next presentation we
           have is from Westinghouse Electric Company on the
           ductility testing of the Zircaloy-4 and ZIRLO cladding
           after high temperature oxidation and steam.
                       Just for Mr. Garner's benefit we will
           acknowledge this as a Garner presentation or the
           previous presentation as a Garner presentation.
                       MR. LEECH:  Good morning.  My name is Bill
           Leech of the Westinghouse Electric Company.  I'm also
           accompanied this morning by Mitch Nissley, who is
           sitting back and has already responded to several
                       We're both engineers at Westinghouse.  I
           am a mechanical engineer primarily in the area of fuel
           rod and modeling and data analysis, and Mitch is also
           a mechanical engineer with an emphasis on thermal
           hydraulics, and his primary emphasis is on LOCA
           modeling and methods development.
                       Our purpose here is to give you an
           overview of some of our current work in determining
           the properties of both Zircaloy-4 and ZIRLO after high
           temperature oxidation and steam.  Again, this is an
           ongoing program.  We started it in late January, early
           February as a result of some of the information
           discovered by Dr. Meyer.  It's an ongoing program.  It
           has still some time to go to completion, but we do
           want to give you an update on what we've discovered so
                       Now, just some background, and I'm sure by
           now you've heard it, but let me repeat it once more. 
           The ductility measurements on Zircaloy oxidized in
           high temperature steam were used to establish the
           embrittlement criteria, 10 CFR 5046.  And those, in
           fact, are the basis of the two criteria, of the peak
           cladding temperature of 2,200 and an ECR limit of no
           greater than 17 percent.
                       Now, testing consisted in the early '70s
           of both quench tests and ring compression tests. 
           However, we  were aware of the presentation by Mr.
           Hache of France, and we went back and thoroughly
           reviewed the Commission's deliberations, the staff
           evaluations, and agree with him that these were
           primarily based on ring compression tests, and quench
           tests were simply used as confirmatory data.
                       And the purpose of the criteria was,
           again, to insure cladding would remain sufficiently
           intact to assure easily coolable geometry, and as a
           practical matter, they met that criteria simply by
           assuring themselves that after the transient was
           completed, the cladding would retain some ductility. 
           So basically it's a ductility retention after the
                       Now, before we proceed, I'd like to talk
           a little bit about ZIRLO.  ZIRLO is our advanced
           alloy.  It was developed actually starting about 20
           years ago, included autoclave tests, extensive tests
           in the BR-3 reactor in Belgium, and reactor
           demonstrations here starting in the '80s, and it's up
           really now to basically full implementation.
                       There may be several of our reactors that
           don't have ZIRLO, but there are very few, maybe three
           or four.  Well over 90 percent of our cladding we
           manufacture now with ZIRLO.  That includes both ZIRLO
           cladding, ZIRLO thimbles and ZIRLO grids.
                       To date, the peak rod burnups that we've
           gotten are 70,000.  Those are a limited number of rods
           at North Anna.  We have had four assemblies in the
           V.C. Summer reactor with individual rods that have
           gone over 66,000.
                       We have taken extensive in pile
           measurements both on the growth, corrosion, creep,
           growth, both axial growth of the rods and the
           assemblies and lateral growth of the grids.  Generally
           we find that for equivalent corrosion duties, the
           corrosion is probably 60 percent of what we get for
           Zircaloy-4.  Creep and growth are about half.
                       So these questions I'm sure you would ask
           later if I didn't answer now, and that's what our
           experience has been.
                       So we do consider it in all ways a much
           better alloy for normal operation.
                       DR. UHRIG:  One question.
                       MR. LEECH:  Yes, sir.
                       DR. UHRIG:  It's described here as being
           low tin content.  Do you have a number?
                       MR. LEECH:  It is one percent nominal tin.
                       DR. UHRIG:  What?
                       MR. LEECH:  One percent nominal tin, yes.
                       DR. UHRIG:  One percent.
                       MR. LEECH:  Again, we started licensing
           this in 1991.  The firm formal licensing process was
           initiated, and there was an extensive testing program
           that supported that included material mechanical
           properties, density, thermal expansion, thermal
           conductivity, specific heat, phase changes, high
           temperature creep, high temperature oxidation at rod
           burst.  Plus there was an extensive irradiation
           program in the BR-3 reactor.
                       And our conclusion was there were some
           phase change characteristics because of the
           composition.  The phase change from alpha to beta
           takes place at a lower temperature.  I don't recall
           the exact number.  I believe about 75 degrees
           Centigrade.  So it is a lower phase change.
                       Other than that, we found that the
           mechanical properties were essentially identical.
                       DR. CRONENBERG:  Did you show any changes
           in creep with sulfur, too?
                       MR. LEECH:  Creep?  That becomes a
           complicated question because creep is a function of
           both thermal creep and in reactor radiation induced
                       DR. CRONENBERG:  But I'm just thinking of
           the presentation before where he said sulfur affected
           their creep.
                       MR. LEECH:  We did not make any attempt to
           see if sulfur had an effect on creep.  The overall in
           reactor creep is lower.
                       Now, as I say, that gets complicated
           because that doesn't necessarily mean the thermal
           creep.  Out of pile thermal creep is lower.  The two
           components really interact, and we find must less
           irradiation creep.
                       So the overall in reactor creep rate is
           much less.
                       DR. CRONENBERG:  What do you have tech
           specs on for trace elements?
                       MR. LEECH:  I can't answer.  I don't
           recall all of those.  I mean there's a long list of
           them, but I can't remember them.  I can supply them
           for you if you'd like.
                       DR. CRONENBERG:  I'm just curious because,
           you know, prior indications indicated that they
           make --
                       MR. LEECH:  Yes.  I simply can't recall
                       So because we saw that the mechanical
           properties were essentially identical during the
           licensing process, we argued that because of the close
           similarity of Zircaloy, ZIRLO and Zircaloy-4, which
           again has been described to others as simply Zircaloy-
           4 with a little niobium added, that we thought that
           the 17 percent criteria should continue to apply, that
           no additional testing was necessary.
                       The NRC agreed with that, and 10 CFR 5046
           was amended to say state that the acceptance criteria
           applies to ZIRLO.  So that was our licensing history
           on ZIRLO.
                       However, as you know, we got some new
           information.  We became aware of the Bohmert work in
           January.  Ralph had done some research in December, I
           guess, early to mid-December, discovered the Bohmert
           work, several other papers by Griger and the Kurchatov
           Institute.  There were several references that we
           became aware of.  Basically in mid-January we became
           aware of those, and we did a thorough evaluation of
                       And just some of the things that we saw in
           the Bohmert paper, some of the summaries, that the ECR
           to cause complete embrittlement -- this is for the
           E110 alloy -- is about one third the value for
           Zircaloy-4, and that is, in fact, also consistent with
           other work that was done with E110.  So it was not
           only Bohmert.
                       However, in looking at that, we also
           noticed a number of physical differences in the oxide
           layers of E110 and Zircaloy-4, and several of the
           things that Bohmert mentioned was E110 displays a
           heterogeneous appearance to the oxide layer; that
           typically if we look at the oxide layer, there were
           two separate oxide layers separated by cracks, and
           these tend to play -- multi-oxide layers do tend to
           play, and his tests, the Zircaloy-4 always had a
           glossy black, firmly adherent single layer, relatively
           free from mechanical failures, and he noticed a high
           hydrogen uptake -- low hydrogen uptake.  I'm sorry. 
           He noticed low hydrogen uptake only if firmly
           adherent, crackless oxide layers were formed.
                       So there seemed to be a good correlation
           between the hydrogen pickup and the condition of the
           oxide layer itself.
                       Our previous history, particularly in high
           temperature steam oxidation tests that we had done as
           far as the high temperature burst test, showed that we
           always had glossy, shiny, adherent, black oxide layers
           on both Zircaloy-4 and ZIRLO.  So we suspected right
           away that there was some difference, and it may have
           something to do with the oxide layer.
                       And let me see if -- however, again, we
           thought that in the review of all the papers Ralph had
           raised some pretty good points, and we really did feel
           that we should do some experimental work and verify
           that the 17 percent limit continued to apply.
                       So we did.  Having said that though, let
           me reiterate that one other thing we wanted to look at
           was clearly to make the point that ZIRLO and E110 are
           not equivalent for a number of reasons, and the number
           one reason of course is that ZIRLO also contains tin
           here at the one percent level, a substantial amount of
           tin.  It contains iron.  The iron level is a tenth of
           a percent, and it does contain oxygen.  The spec on
           oxygen is about .125 percent, or 1,250 parts per
           million, whereas in E110 it's typically 700 parts per
           million.  So there are some differences.
                       Again, the tin and oxygen are alpha phase
           stabilizers, which means that the transition
           temperature from alpha to beta is slightly higher when
           those are present, or somewhat, just slightly higher,
           about 100 degrees or so higher than it would be in a
           zirconium-niobium binary alloy.  So there are some
           differences in the phase change temperatures.
                       We see simply varying differences in the
           structure of the oxide layer.
                       But we did decide to run some tests, and
           we put together a test rig in February.  Let me
           explain to you what it does.  Okay.  The main test
           section is an Iconel tube here, and inside this
           basically are two test specimens.  The two test
           specimens are a piece of ZIRLO tubing and a piece of
           Zircaloy-4 tubing.
                       So we're putting both tubing types in and
           testing them simultaneously.  They're held in here. 
           Basically there's a sheath thermocoupler that goes up
           here.  It has a small ring on it, and we sit the
           samples on top of that.
                       So here in the constant temperature zone
           we have a short piece of ZIRLO tubing, a short piece
           of Zircaloy-4 tubing.  In alternate tests, we actually
           rotate them.  So one time one is on the top; one time
           the other is on the bottom.  So we rotate them.
                       And basically the objective here is to
           oxidize them under identical conditions, and then test
           them and see how the results compare.
                       This is a resistance furnace.  It's a
           clamshell furnace.  We preheat it to about 500
           degrees, open it up, and then slide the test section
           in, close the clamshell and start the heat up.
                       We go to final temperatures.  We actually
           have some thermocouples on the outside of here,
           outside of the test section which controls the power
           when we get to the final temperature.  
                       We have, again, I said that there was a
           main sheath thermocouple coming up through here which
           sits in the middle of the tubes.  So we have
           temperatures -- both two temperatures on the outside
           and then the temperature on the inside, and typically
           they're within three or four degrees of each other. 
           So we are getting fairly uniform heating.
                       Okay.  We have basically de-aerated water
           from an autoclave.  It's pumped through our system. 
           There's a steam pre-heater.  We introduce steam into
           the test section.  Actually prior to heat-up we run a
           purge gas through it, purge gas.  There's another line
           which is not shown here.   Purge the system, heat it
           up, and start the steam flow through it.
                       We run it then through a steam condenser. 
           The hydrogen is vented out to the atmosphere, and we
           actually condense the steam so we know what the steam
           rates were and how much steam we run through.
                       Again, the heat-up rates here.  There has
           been some discussion of what the heat-up rate should
           be.  In this apparatus, our heat-up rates are about
           one degree Fahrenheit per second.  Now, that is --
           Mitch, how is that relative to LOCA heat-up rates?  I
           meant to ask you that.
                       MR. NISSLEY:  For a large break LOCA,
           typical heat-up rates would be on the order of ten to
           15 degrees Fahrenheit per second.  Small break LOCA
           might be as low as two or three degrees Fahrenheit per
           second.  So that is a little low.
                       MR. LEECH:  Okay.  So this is somewhat
           slower than the actual.  It is somewhat significantly
           faster than Bohmert used.  He used, I think, heat-up
           rates of about one third that.  I believe he was using
           about a third of a degree per second.
                       The final temperatures when we got the
           temperatures ranged from 1,800 degrees Fahrenheit to
           2,200 degrees Fahrenheit, which is, I believe, 986
           degrees Centigrade to 1,204 degrees Centigrade.
                       We did run another test.  We've run one at
           1,700 degrees Fahrenheit, which is 926 degrees
           Centigrade, because as we'll discuss later, there was
           some concern that there was a temperature range
           between 950 and 1,000 identified by Bohmert where he
           seemed that the E110 alloy was particularly
           susceptible to hydrogen pick-up.  So we ran that test.
                       Okay.  We studied those for times ranging
           from five to 30 minutes.  At the end of the time at
           temperature, we opened up the clamshell furnace, let
           the section cool by both radiation and convection. 
           The cooling rates averaged about nine degrees per
           second for the test temperature down to 1,000 degrees.
                       Then, again, Mitch, you had some ranges. 
           I believe that's reasonable.
                       MR. NISSLEY:  A pretty good cool-down.
                       MR. LEECH:  Pretty reasonable with what we
           might actually expect.
                       We don't quench.  We let it cool
           completely to room temperature.  Now, the objective
           here is not to run a quench test to see when we fail
           during quench, but to prepare specimens for subsequent
           ring tests.
                       We believe that if anything, this may be
           somewhat conservative in that we have a relatively
           slow cool-down rates for long periods of time.  So if
           there is going to be any oxygen infusion to transform
           the prior beta phase, then this gives it more time to
                       So basically the purpose here is to get
           specimens for ring compression tests.
                       Now, let me just give you the status of
           where we are in the process.  We have done now --
           where my notes are -- I would say we've oxidized about
           three quarters of the specimens that we expect to
           oxidize.  Let's see.  Okay.   Let me first tell you
           what we're going to look at before I tell you how many
           we've done.
                       First of all, the number one priority is
           oxide layer characteristics.  We believe that of all
           the things that we've seen with E110 and Zircaloy-4,
           that seems to be the biggest difference, and we want
           to take care to look at those.  We're doing those by
           optical metallography and just general observations.
                       The next thing would be ring compression
           tests to assess the cladding ductility.  Those will be
           done at room temperature at 275.  Two, seventy-five,
           I believe, is the official number at which the 17
           percent criteria was set up at.
                       With a tester similar to those performed
           by Hobson and Rittenhouse in ORNL report in 1972,
           we've attempted to maintain the same length-to-
           diameter ratios of the specimens, maintain the same
           head speed on the compression rate on the slow
           compression rate tests, and these were also similar to
           Bohmert, although there were slight differences.
                       Well, one thing that we did different was
           Hobson and Rittenhouse only went to a fixed
           displacement and stopped their compression test, where
           Bohmert continued to going until he either got clear
           indications of a failure or was getting too close to
           where he simply couldn't compress them anymore and
           backed off.  We did that.  We thought it gave a little
           more information.
                       There are some other differences. Bohmert 
           cut his specimens into short sections prior to
           oxidizing them, where we oxidize a specimen about that
           long, and then we cut the rings out afterwards.
                       We measure the weight gain of the total
           specimen, and then we cut sections out of it, which is
           a slight difference, although I don't think it should
           make much difference.
                       Again, we cal look at the oxide thickness. 
           We're going to look at the thickness of the alpha
           stabilized layer and the transformed beta layer.  We
           will do micro hardnesses across the cladding wall to
           assess the oxygen penetration, and then we'll do
           measurements for total hydrogen and oxygen
                       There's some of the matter we've gotten so
           far.  What this is is a plot of the measured oxide
           thickness in microns.  This was developed from
           metallography, plotted versus the oxide thickness that
           would be present if all the oxygen weight gain was
           transformed to an oxide layer.
                       And so there's a couple of interesting
           things here.  One is that if you look, you'll see that
           if all the oxygen had been done into an oxide layer,
           then we would expect to go across about -- for a
           prediction of 100, you go across and we actually
           measured 70, which indicates that about 70 percent of
           the oxygen is going into the oxide layer and about 30
           percent is going into the metal.
                       But what we also noticed is that for
           Zircaloy-4 and ZIRLO they're identical.  There's
           really no difference between them, and I think that's
           a key difference because in one of the papers, when
           they looked at the E110 alloy they said that although
           for equivalent weight gains the distribution of the
           oxygen could be significantly different.  A much
           higher percentage of it actually for E110 has ended up
           in the metal rather than the oxide layer.
                       So we believe that's a significant
           difference.  We don't see any difference here between
           ZIRLO and Zircaloy-4.
                       Anything else I might want to say about
           this?  No.
                       Then the next result we have are the
           results from the ring compression test.  These are the
           ones we've done at 275 degrees Fahrenheit.  What we've
           plotted is the relative displacement of failure. 
           Relative displacement is the amount of compression
           divided by the other diameter of the specimen versus
           the measured ECR fraction.  Now, this is not
           calculated; measured.  There's an important
           distinction there, and that's the ECR assuming all the
           oxygen weight gain is stoichiometrically combined with
           the metal.
                       We see several things.  One is we see that
           Zircaloy-4 and ZIRLO are for all intents and purposes
           the same over the whole range that we've tested.  We
           see no difference whatsoever.
                       This is Bohmert's brittle limit.  Whether
           that's our brittle limit or not, that still needs to
           be investigated because we need to look at each of
           these specimens and look at the nature of the failure. 
           Was it brittle, ductile, or partially brittle and
           partially ductile?
                       We know from already that these were
           clearly brittle, and some of these actually are still
           in one piece, you know.  After we bent them down,
           they're still in one piece.  So they're obviously
           ductile, but we have to take some care to look into
           this area to suggest exactly what is the ECR at which
           we get transition or we are in a position where we're
           totally brittle.
                       Again, one other thing I might mention,
           too, which I haven't plotted, haven't shown you. 
           We're also doing this at room temperature, and we've
           looked at some of the preliminary results that we got
           for Zircaloy-4 at room temperature, and they're
           reasonably in good agreement with what Bohmert got in
           his test for Zircaloy-4, which again is another,
           probably a second opinion that what he did was really
           pretty good work.  There was no problem with what he
           did.  It's just that the E110 seems to be
           substantially different than Zircaloy-4 because our
           Zircaloy-4 results seem to be consistent with his.
                       So which I guess is good.  It tells us our
           Zircaloy-4 results were consistent with his, and our
           ZIRLO results are essentially equivalent to our
           Zircaloy-4 results, indicating that for ZIRLO-4
           there's no reason to think that the 17 percent
           criteria doesn't continue to apply.
                       This, again, is measured ECR.  It's not
           Baker-Just.  Baker-Just probably is conservative by a
           factor approaching two.  So we don't see a problem.
                       Again, what did we see?  Just comparisons. 
           Both oxide layers were dark adherent with no
           laminations.  Both have similar fractions of oxygen in
           the oxide layer and in the metal.  Ring compression
           tests of similar values of displacement of failure
           versus the measured equivalent planning reactant.  We
           believe that the ZIRLO and Zircaloy-4 are just
           essentially exhibiting the same behavior.  I see no
           difference at this point.
                       Again, we still have some more work to do
           on this.  We're going to prepare for the remaining
           sample preparation.  We've got to complete all the
           tests.  We have got a few more samples to prepare. 
           We've got some of the -- about a third of the ring
           compression tests to still do.  The metallography
           samples have been made, etched.  They have not
           necessarily all been evaluated yet.
                       We want to get all of the data, and what
           we really want to do then is get a good independent
           review.  Those of us working on the project have
           reached our conclusions, but we want to bring in
           outside people both from in our company and
           potentially from outside the company to look at what
           we've done, document and review the results.
                       And our next scheduled meeting to discuss
           this with the NRC now is May 16th, I believe.  There
           will be a review meeting.  So we'll give another
           update at that point.
                       That really is what I planned to say
                       CHAIRMAN POWERS:  You mentioned several
           times that your Zircaloy oxides showed no evidence of
                       MR. LEECH:  Right.
                       CHAIRMAN POWERS:  And the previous speaker
           showed some micrographs in Zircaloy-4 that had
           evidence of delamination.
                       MR. LEECH:  Okay.  Excuse me.  One of
           those, I believe, was after spalling, wasn't it?  Was
           that before or after?
                       After spalling it certainly showed
                       CHAIRMAN POWERS:  I guess my question is,
           really boils down to:  what causes the delamination?
                       MR. LEECH:  What causes?  Obviously it's
           a stress and a differential thermal expansion.
                       CHAIRMAN POWERS:  Okay.
                       MR. LEECH:  But what causes one to crack
           and one not to crack, I guess I don't -- I don't know.
                       CHAIRMAN POWERS:  Okay.
                       MR. LEECH:  I don't know.
                       CHAIRMAN POWERS:  Any other questions of
           this speaker?
                       (No response.)
                       CHAIRMAN POWERS:  Well, thank you very
                       MR. LEECH:  Thank you.
                       CHAIRMAN POWERS:  Our next speaker has
           protested he's hungry, and so I'm going to recess for
           lunch, and we'll pick up Dr. Meyer's discussion of his
           OECD meeting after lunch.
                       Thank you.
                       (Whereupon, at 11:58 a.m., the meeting was
           recessed for lunch, to reconvene at 1:00 p.m., the
           same day.)
                                A-F-T-E-R-N-O-O-N  S-E-S-S-I-O-N
                                                    (1:01 p.m.)
                       CHAIRMAN POWERS:  Dr. Meyer is going to
           give us a precis of the OECD topical meeting on LOCA
           fuel safety criteria.  
                       DR. MEYER:  The meeting was organized by
           an OECD related group.  Within CSNI there are several
           special expert groups, and there's one on fuel, on
           fuel safety margins.  And it is this group, on which
           I am a member, that organized the meeting.
                       We'd had a similar meeting.  A similar
           group in OECD had organized a similar meeting in 1995
           on the reactivity accidents, very early in the period
           where we were looking into that.  And it was very
           helpful because it brought a lot of people out of the
           woodwork and got a lot of information out in public
           that could be talked about.
                       And we decided before the Bohmert paper
           surfaced to organize this meeting, but when we learned
           about the Bohmert paper, it became sort of the center
           of focus of the meeting.  
                       So the meeting really had three groups of
           papers:  one on post quench ductility, one on axial
           constraints during quenching, and one on relocation of
           fragmented fuel into the ballooned region.
                       I have more material in the handout than
           be covered in a reasonable amount of time.  So I think
           I'm going to just focus on this first group here.  And
           also I'll skip over quickly some things that have
           already been discussed.  
                       The first couple of slides in the package
           were from an introductory presentation by George
           Hache.  They go over the ECCS rulemaking hearing and
           the fact that the criteria were developed from ring
           compression tests and that's been discussed, and I
           don't think that's a matter in contention.  So I'll
           just skip that.  
                       Now, Bohmert is from a research institute
           in Dresden, Germany.  I did contact him.  He was
           unable to attend the meeting.  But George Hache
           presented, among other things, the main slide, the
           main figure from Bohmert's report in 1992 that shows
           the effect.  
                       Now, you saw a few of these points on
           Framatome's slide, where they picked out the ones at
           1,100, and they picked those out from Bohmert's slide
           and showed them on their graph.
                       But Bohmert had tested over a wide range
           of temperatures, both Zircaloy-4 and the VVER
           cladding, E110.  And you can see this is the line that
           was on the Framatome slide.  And you can see it coming
           down here around five percent cladding reacted.
                       I think Bohmert did his tests at room
           temperature.  And George Hache looking back at all
           this says, "Well, it really should have been at 135
           degrees Centigrade," so it would be a little higher
           than that.
                       But nevertheless you can see here,
           although there is scatter in the data, you can see a
           separation between the E110 ductility results and the
           Zircaloy-4 data results.  
                       Now, Bohmert is not the only person who's
           seen this.  This has been seen at four different
           laboratories in four different countries, was seen in
           Germany.  It's been seen in the Czech Republic, in
           Hungary, and in Russia.  
                       The Hungarian researcher who did the
           confirming work there was present at the meeting and
           has a paper and I have a slide from that. 
                       The Czech researchers did not document it
           in a public place or in English.  They wrote it up in
           a agency report in Czech, whatever, in Czech.  But we
           have contacted them and we may be able to retrieve
           that data and get it in an English report.
                       And then in addition to that, George
           Hache, who has this incredible talent to remember
           things from obscure places, remembered some meeting in
           Varna.  I don't even know where Varna is, in 1994
           where the Russians presented such results.  
                       And so added to the three that we had been
           talking about, the Germans, the Czechs, and the
           Hungarians, here is the Bochvar Institute with ring
           compression test results and a line that separates the
           ductile from the brittle behaving specimens.
                       And when George -- this handwriting is
           George Hache's.  He's informal sometimes.  When he
           goes down this separating line down to the 135 degree
           temperature point, and he gets the six percent figure.
                       So George says, "If you apply Hobson's
           methodology to this set of data from the Bochvar
           Institute, you get a six percent ECR," which is
           consistent with the others that we have seen.  
                       Now, the main presentations on this
           subject were given by Maroti from Hungary, Sokolov
           from Russia, Lebourhis from France, Bill Leech out
           here in the audience, and Hee Chung from our program
           at Argonne.  
                       There were actually two papers on the
           subject from Russia and I only have a slide from one
           of them.  The other one was kind of preliminary, and
           frankly, I was never able to understand the main
           results of that paper and have gone back to try and
           get clarification.
                       So let me just show you a few of the
           slides which are fairly easy to grasp, and which I
           think will summarize the essence of the material that
           was presented at the meeting.  
                       This is the Hungarian work, and I think
           it's even cleaner in appearance than the Bohmert work
           in terms of seeing the drop-down in the ductility of
           the E110 specimens compared with the Zircaloy
                       It's interesting that at least in the
           German, the Czech, and the Hungarian work, they always
           measure Zircaloy along with their E110 measurements. 
           So there's a control.  And Hee Chung at Argonne has
           taken their Zircaloy results and replotted them along
           with his own ring test results from the '80s and
           Hobson's from the '70s, and they're all consistent,
           which is what we heard this morning as well.  
                       So all of these laboratories appear to be
           able to make consistent measurements on Zircaloy, and
           we get these two sets of differences for the zirconium
           1-niobium, and the difference is remarkable.  It's not
           just a small difference.  I mean, from 17 percent to
           six percent is a huge reduction.  
                       Now, Sokolov in his presentation included
           this figure, and George Hache made interesting
           observation from this figure.  This is not ring
           compression tests, now.  These are quench test
           results.  This is a failure map, and we often plot
           failure maps like this where we have the log of the
           time, the temperature versus one over temperature, and
           show on the plot usually the 17 percent line which
           would go on down, but then truncated by the 2,200
           degree Fahrenheit curve.
                       And I'll show you a figure for Zircaloy. 
           Generally, there is a substantial margin shown above
           the boundary until you get to the beginning of the
           failures.  And you see, you see a margin along here,
           but when you get to 1,200 degrees the ductility seems
           to start a nosedive, and you have very little to no
           margin right here at the knee in the curve.  
                       Now, that was presented -- that figure was
           presented at the meeting by Sokolov.  George Hache
           makes the observation during the discussion and George
           Hache -- I don't know if he used these exact figures,
           but he pointed me to them and we got them out of our
           own reports.
                       But this is a failure map for Zircaloy
           test summarized in a report by Van Houten, but Van
           Houten didn't do the work.  This work was done at
                       Okay. The construction lines are not laid
           on this figure, but the data points are, and what I'm
           going to show you on the next figure, now, is a figure
           with construction lines on it and no data points, but
           it's the same figure, and you'll see this is Figure 2A
           from the reference and this one is Figure 2B from the
           reference.  And this solid curve here, then, is the
           one that bounds the thermal shock failures.
                       There's some other things on here.  And
           here is the construction that shows the 17 percent
           line and the 1,200 degree limit.  And you see quite a
           bit of margin, and across here there's a good 100
           degree C. margin in this, which appears to be absent
           from the E110 plot.  
                       Just an observation that George is saying
           is not only the ring compression test that are giving
           us this message.  There's the quench tests that are
           giving us this message.  
                       Okay.  Now, I'm not trying to suggest that
           this is the same message, but this morning in the
           Framatome presentation we did see numbers that were
           close to the 17 percent line which don't have a lot of
           margin exhibited.  I don't know whether that's
           significant or not significant, but I point it out to
                       On the other hand, and you saw both of
           these, this one and the Westinghouse figure before,
           there is just no difference apparent at all when you
           do the ring compression -- when you look at
           Framatome's ring compression test and Westinghouse's
           ring compression tests.  So you saw these slides this
                       I ask Labourhis directly at the meeting
           what was his opinion as to why there was such a
           difference between E110 and M5.  And his answer to me
           was, "I have no idea."  
                       Now, there's a suggestion that there's a
           difference in the material.  There are some
           differences in the test procedures. 
                       Nothing is apparent at this point.   It's
           pretty much a mystery.  
                       George Hache makes another observation
           which is rather obvious, but kind of important at the
           same time, is if it really is a difference in the
           material, we kind of ought to understand it because we
           may inadvertently move into that material regime.  And
           it makes a big difference.  
                       Now, you were asking some questions about
           the composition, and I have compositions of E110 and
           M5 from a couple of sources.  The main points in this
           table are from a recent Halden report, where they're
           testing specimens.  I don't know whether they're
           coupons or tubular specimens, in some oxidations
                       And they have reported these numbers. 
           These look like -- I would say these look like numbers
           that were measured, but I'm not sure about these
           numbers here.  
                       Anyway, there are also papers in the open
           literature in the ASTM, you know, the zirconium in the
           nuclear industry conference that they hold every three
           or four years.  
                       There's one with M5 results written by
           Framatome authors, and one with E110 results written
           by Russians that show these ranges.  And you can see
           a few hundredths of a percent more oxygen in M5 than
           in the E110, and the iron, there's a little more iron. 
           It's a very small amount.  
                       Both are recrystallized.  The E110 is said
           to be alpha recrystallized, so it's recrystallized. 
           It's annealed at a temperature below the phase
                       DR. BONACA:  Does it show sulfur there?
                       DR. MEYER:  Huh?
                       DR. BONACA:  Does it show sulfur?
                       DR. MEYER:  No, I couldn't find any sulfur
                       DR. BONACA:  We heard this morning
           about --
                       DR. MEYER:  Yeah.
                       DR. BONACA:  -- M5, I thought.
                       DR. MEYER:  Did mention the sulfur this
           morning, and I don't have any numbers on that.  
                       I'm not sure that the cold work and the
           annealing is going to make any difference when you get
           into this regime of oxidizing above the face
           transition.  It just seems to me like it's a soup of
           elements at those temperatures, and the chemical
           composition is really close.  
                       I simply don't understand it.  I don't
           have a theory or, you know, a big hunch.  It's just
           hard to believe that it's the test procedures because
           they use controls all along.  It's hard to believe
           it's the material because the material is so similar. 
           It's hard to believe that it's the fabrication and
           cold work related things because it's a high
           temperature process that we're looking at, and I don't
                       Now, at this point in the meeting Hee
           Chung gave a lecture.  Bill Shack will understand that
           Hee Chung likes to give lectures, and he gave us a
           lecture on a post quench ductility of zirconium
           alloys.  And he repeated a number of things that we
           already knew and were talking about.
                       But he did bring out a couple of other
           points.  I'm not sure whether all have been verified
           or not.  But he points out the matter of the hydrogen
           induced ductility.  And that hydrogen induced -- the
           role of hydrogen in reducing ductility wasn't
           understood in 1973, when Hobson's tests were done.  
                       It was all thought to be oxygen.  The
           levels of hydrogen in the specimens at that time were
           low, less than 150 parts per million, where it
           wouldn't have been above the threshold for some effect
                       But let's see if this is the -- well, I've
           got a couple of figures here.  
                       Hee Chung now points out that for
           Zircaloy, that there seems to be a threshold around
           600 or 700 ppm hydrogen. When you get that much
           hydrogen in the specimen, then it also contributes to
           the reduction of ductility.
                       And he has looked at Bohmert's data and
           Griger's paper.  Griger is one of the Hungarian
           workers, and believes that he sees a threshold at a
           much lower level, down around 150 to 200 parts per
           million.  Now, in the specimens that we heard about
           this morning, the concentration of hydrogen was even
           lower than that.  So you wouldn't have been there.
                       And Hee Chung insists that we have to
           consider several factors and not just one.  It's not
           just hydrogen.  It's not just oxygen.  It's not just
                       And then he presented this one slide,
           which is rather useful, to talk about the three routes
           to getting a lot of hydrogen in the specimen and how
           we only have hydrogen from one of these routes in the
           specimens that we're testing at this time.
                       You can get hydrogen during normal
           operation, and of course, we have not been testing
           that because the tests that we've been looking at have
           been on fresh tubes.  
                       You can get hydrogen in the high
           temperature process.  This is what we've been looking
                       And then there's another process that lets
           hydrogen into the cladding associated with the
           deformation during ballooning and rupture.
                       And this, I believe, is the process that
           led them to identify the role of hydrogen in
           embrittlement because apparently when you get this
           deformation, and you now have two-sided oxidation, you
           have a stagnant steam environment on the inside and
           the hydrogen doesn't get swept away, and the
           absorption of the hydrogen locally in that region is
           very high.
                       And so when they -- this work was done at
           a couple of -- I guess it was done at Argonne and it
           was also done at JAERI, in the early '80's.  And when
           -- if you took slices near the region of the burst,
           took rings and looked at their ductility, they would
           not pass the non-zero ductility test related to 17
           percent oxidation.  So there's a local effect that's
           fairly strong.  
                       Well, this slide suggests the importance
           of making some measurements on some real fuel rod
           material and not just on tubes in the laboratory.  And
           of course, that's what we are interested in doing in
           our research program.  
                       And then I was asked to give a brief
           presentation on our research program, and these are a
           couple of slides that I used.  The first bullet
           outlines the program that we have at Argonne at the
           present time using Zircaloy.  There have been some
           adjustments to this based on the PIRT process that was
                       And now that we have our Zirc-2 and Zirc-4
           in the laboratory and those tests are planned and
           ongoing, we'd like to start making arrangements to
           obtain some ZIRLO and M5 in this program.  
                       And as I think I mentioned earlier, we
           broached this subject with Framatome and Westinghouse
           at the meetings that we had in February here at NRC.
                       I think that if we carry out this full
           range of studies with Zirc-2 and Zirc-4 that we may
           not need to repeat everything in that menu for the
           other cladding types.  We might, for example, be able
           to skip the integral tests.  It's an expensive test. 
           I'm not sure that we'll be able to, but you might be
           able to characterize things well enough from them,
           from the simpler tests that they were measuring
           mechanical properties.  
                       And so, in particular, we're quite sure
           that we'd want to do oxidation kinetics measurements,
           probably some sort of thermal shock test, look at the
           oxidation and the phase relations and measure the
           mechanical properties after running the material
           through a high temperature oxidation transfer.
                       DR. KRESS:  Ralph, this looks to me like
           more data is going to an empirical relationship.  Does
           this address Mr. Hache's comment or we need to
           understand the effects of small material differences? 
           I don't see that it addresses that. 
                       DR. MEYER:  You don't see it directly, but
           it -- we really want to -- I'm not convinced that it's
           a small materials difference that's doing this.  And
           so one of my main objectives is to find out what it
                       DR. KRESS:  Okay.  This will do that.
                       DR. MEYER:  Well, it will for it's part of
           the equation.  The other part of the equation is the
           E110 alloy.  And what you don't see up here, but it's
           buried in one of the bullets on another -- in another
           presentation, was that we have this program with the
           Kurchatov Institute, and in starting in late 2001,
           this year, late in the year, we have them beginning a
           series of tests that are designed to shadow this
           program in their laboratory with E110.  
                       So we want to look very carefully at ring
           compression tests, whether that's the right test or
           not.  These tests have been criticized in the past. 
           They're not real precise.  They're good screening
           tests for some purposes, but maybe an axial tensile
           test might be a more precise way of looking at the
           ductile brittle behavior.  
                       CHAIRMAN POWERS:  When you look at you
           specimens, it looks to me like chemical compositions
           not going to answer the question for you.  They're too
           close together.  
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  Now, maybe EDAX on the
           distribution of the alloying agents may be different. 
           Maybe that tells you something, but do you also look
           at things like grain size and surface texture?  
                       DR. MEYER:  Well, we would.  I don't think
           we're far enough along to say what we have planned out
           in a test matrix, but those are the easy things to
           look at, and the kind of things that we would normally
                       DR. CRONENBERG:  Ralph, a couple years ago
           you had voted the idea of a 100 calories per gram for
           high burnup --
                       DR. MEYER:  Yeah.
                       DR. CRONENBERG:  -- plus a criteria of
           retention of residual ductility, that maybe the two
           might be the way the regulation should be written up. 
           Does this flow from that thinking?  
                       Is that thinking still in effect that
           there might be a requirement of some residual
           ductility rather than hydrogen and oxygen, then oxygen
           and hydrogen uptake?
                       DR. MEYER:  It's not really connected,
           although you come out at about the same place.  The
           100 calorie per gram dealt specifically with a rod
           ejection type accident.  And that's a accident where
           the cladding remains at a relatively low temperature,
           and where you haven't gone through a phase
           transformation and wiped out its fabrication history
           and all of that.  
                       Now, the ductility initially when we were
           looking at the rod ejection, we were trying to see if
           we could use the ductility criterion instead of an
           enthalpy criterion.  
                       And the critical strain energy density
           method that EPRI and the industry use, and that IPSN
           uses and EDF uses, is, in effect, a ductility based
                       But the origin of the two are quite
           different because at that time we weren't thinking
           about the ECCS hearing and what was done there and
           Hobson's results, and so forth.  
                       DR. CRONENBERG:  Okay, but I guess I'm
           still not clear.  Is your thinking still in terms of
           residual depility (phonetic) criteria?  Is this still
           in the background for these experiments?
                       DR. MEYER:  Certainly for the LOCA it is,
           definitely.  I mean, this is the result of the
           hearing,and the philosophy we've been following even
           though we forgot that we were following it.  
                       I mean, that was these criteria that we're
           using were based on retained ductility.
                       DR. CRONENBERG:  But it's 10 percent
           oxidation, not in ductility requirements. 
                       DR. MEYER:  Yeah.  So we may have to roll
           it back to the concept of ductility and look again at
           what attribute might characterize that adequately for
                       DR. CRONENBERG:  Okay.
                       DR. MEYER:  Okay.  Now, along with the
           work on irradiated fuel rods, we'd like to -- well, we
           always in our program at Argonne, where we're looking
           at irradiated fuel rods, we always look at archive
           unirradiated material and do pairs of tests so that we
           can tell the difference between the behavior of fresh
           material and irradiated material. 
                       There's a lot that we have learned and I
           think we sill can learn with the unirradiated tubing,
           and so if we can make some arrangement with Framatome
           and Westinghouse to work on their materials, we'd like
           to get started very quickly on the unirradiated
                       And here was a list of things that we
           proposed to do in a program in which we would ask for
           their cooperation.
                       And you see at the top of the list is to
           look at ring compression tests and other post quench
           ductility measurements to make sure that we're not
           using a test that itself has some inherent problems.
                       And we would propose to discuss this until
           we get some agreement on what is -- if the ring
           compression test is not the right test to use, what is
           the right test, and then to carry this out.
                       And there's a branch point over here where
           the same instructions go to Kurchatov Institute in our
           corollary program with E110 alloy.  
                       CHAIRMAN POWERS:  The entry on the slide
           that I guess I don't understand, it says no mechanical
           properties or other testing at this time --
                       DR. MEYER:  Yes.
                       CHAIRMAN POWERS:  -- later in the high
           burnup program.  I was wondering --
                       DR. MEYER:  Why?
                       CHAIRMAN POWERS:  -- what other program is
                       DR. MEYER:  In the Argonne program, which
           we often think of as a LOCA program, we also have a
           matrix of regular mechanical properties testing under
           low temperature, higher strain rate conditions that
           match up with the reactivity action.  
                       So there's a lot of mechanical properties
           testing related to rod ejection action and related to
           the ballooning process.  
                       This is before you get to the high
           temperature and the oxidation.  And what we're saying
           here is that for the moment we wouldn't enter into
           those tests immediately.  We would do those in
           connection with the high burnup tests at a later time.
                       It's partly a matter of resources.  It's
           partly a matter of trying to work with the industry so
           that we don't reveal too many things about their
           proprietary materials that aren't necessary to reveal
           at this time in connection with looking for some
           explanation of this LOCA ductility behavior.
                       So that was put in there to try and be
           nice guys.  
                       CHAIRMAN POWERS:  No good deed goes
           unpunished here, Ralph.  
                       DR. MEYER:  And we have a current program
           that's working very nicely with EPRI, and we would
           just pattern it -- pattern it after that.  So I've
           said all of these things.  
                       Now, I have a few more slides from the
           other discussions.  If you don't ask questions, I can
           show them quickly or I can just sit down.  So it's
           your choice.
                       CHAIRMAN POWERS:  Why don't we rely upon
           the members to review the additional material and --
           because I'm anxious to hear what Margaret and Richard
           have to say.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  And thank you for your
                       I'll comment that the ACRS has made a
           suggestion to the Commission that this program be
           given additional resources to test additional types of
           materials, and it sounds like you very much need it
           right now.  
                       At this point, we'll shift gears just a
           little bit and move to the business end of the agency. 
           And Margaret will give us some talk about recent
           operational issues and experience with high burnup
                       MS. CHATTERTON:  Okay.  It'll take me a
           minute to get myself organized. 
                       CHAIRMAN POWERS:  Oh, yeah, we permit
           that.  Have you been running lately.  That's the
           question we want to know.
                       MS. CHATTERTON:  Have I been running
           lately?  Today was a running day, but there wasn't
           enough time.  So I ran Monday.  
                       DR. KRESS:  We messed up your running?
                       MS. CHATTERTON:  You messed up my running.
                       CHAIRMAN POWERS:  You should have
                       MS. CHATTERTON:  Two weeks from Monday is
           Boston.  I will -- did I get this thing on right? --
           I will be back at Boston, which I think will be a slow
           run, but it will be fun, and that's the major thing.
                       CHAIRMAN POWERS:  That's right.
                       DR. KRESS:  Just as long as you don't that
                       MS. CHATTERTON:  No, I don't take any
                       Actually, right now they have a timing
           chip.  It goes on your shoe.  It starts at the
           beginning, and they have a map that you run across
           every five kilometers.  
                       DR. KRESS:  Oh, okay.
                       MS. CHATTERTON:  So they've got your time.
                       DR. KRESS:  They've got you.
                       MS. CHATTERTON:  You can't cheat. 
                       CHAIRMAN POWERS:  Well, you can cheat
           every three kilometers or something like that. 
                       MS. CHATTERTON:  Anyway, I'm here today to
           talk about operational issues and high burnup fuel as
           we've been using them in the last few years.  
                       And here's kind of an outline to some of
           the things that I want to talk about.  It's been a
           couple of years, I believe, since we talked about
           burnup extension activities.  So I thought I would
           just start off with that, talk a little bit about
           where we are on lead test assembly guidelines, some
           recent fuel issues, and then talk a little bit about
           the current fuel reviews that we're in the process of
                       CHAIRMAN POWERS:  Okay.  
                       MS. CHATTERTON:  So as you probably
           remember our basic approach to burnup extension is
           that we're working with the industry to develop a
           strategy and a plan.  It's going to be up to the
           industry to do the testing, to come up with the
           criteria, and then to justify the criteria.  
                       At that point the NRC will review what the
           industry proposes, review their justification, and at
           some point, hopefully, be able to endorse their
           proposal as a regulatory guide.
                       We simply do not have the resources to do
           the research, to come up with the criteria like we did
           in previous times.  
                       So, again, I think you've probably seen
           this.  Our burnup extension guidelines will be working
           with the industry.  We've required that they will give
           them some advice.  
                       Certainly, it must address the current
           licensing requirements, the LOCA, the RAA and the
           ATWS. all of those things that are looked at today.  
                       They'll have to give a justification of
           why any limit that they decide to use is appropriate
           going to higher burnups.  And just as a review, what
           the industry has said they want to do is to go to
           probably 70 gigawatt days for BWRs -- that's the rod
           average -- and 75 for PWRs.
                       We've also told them that some of the
           area's can be risk informed.  That's going to be their
           determination of exactly how they want to handle
           different things.  And, again, it's all going to be
           subject to our review.
                       DR. KRESS:  When you say risk informed, is
           that you're thinking Reg. Guide 1.174, risk informed
                       MS. CHATTERTON:  Yes.  They will be able
           to use some of the guidance that we've given before. 
           They may look at certain things and decide that they
           want to make a proposal that certain things can be
           handled slightly differently on a risk basis.  
                       DR. KRESS:  See, what bothered me about
           that was Reg. Guide 1.174 is based on current burnups,
           and if you're going to extend the burnup, then you
           have a little bit of a circular argument because then
           you have to ask whether 1.174 has the right value of
           LERF in it, for example.  
                       MS. CHATTERTON:  Yes.  
                       DR. APOSTOLAKIS:  But it deals with delta
                       DR. KRESS:  It also deals with absolute
           value of LERF.
                       DR. APOSTOLAKIS:  Yeah.  So I mean I don't
           understand what it means that --
                       DR. KRESS:  Even delta LERF is going to be
           hard to determine because you're dealing with the
           delta fission product maybe.  And it's not just
           inventory.  You can handle that pretty easily.
                       DR. APOSTOLAKIS:  In other words, what
           you're saying is LERF might not be the right metric. 
           Is that what you're saying?
                       DR. KRESS:  That's another issue I have.
           That's a separate issue.
                       DR. SHACK:  But I think he was arguing
           that acceptance criteria value.
                       DR. KRESS:  Yeah.  I was arguing on --
                       DR. APOSTOLAKIS:  On the acceptance
           criteria is acceptance criteria.  Why should it be any
                       DR. SHACK:  Well, I suppose you could look
           at it that way, too.
                       CHAIRMAN POWERS:  Well, if Tom is thinking
           the way he has been thinking in the past he says,
           "Hold it."
                       DR. APOSTOLAKIS:  Says what?
                       CHAIRMAN POWERS:  He says, "Hold it."  You
           derived your acceptance value by looking at the
           quantitative and health objectives.
                       DR. KRESS:  Absolutely.
                       CHAIRMAN POWERS:  Now, you can't do that
           anymore because the derivation path doesn't work.
                       DR. KRESS:  That's right.  That's exactly
           the way I was thinking.  
                       DR. SHACK:  The source term is different. 
                       DR. KRESS:  Yeah, maybe.  We don't know.
                       DR. APOSTOLAKIS:  The quantitative health
           objectives don't change, do they?
                       CHAIRMAN POWERS:  We assume those are are
           given to us by God.  
                       DR. APOSTOLAKIS:  Working backwards, you
           have assumed certain behavior in severe accidents. 
           And that's what's going to change?
                       DR. KRESS:  Yes.
                       DR. APOSTOLAKIS:  Okay.  So the LERF value
           then may change.
                       DR. KRESS:  That's what I was saying. 
                       DR. APOSTOLAKIS:  Now, the CDF will not
                       DR. KRESS:  No.  
                       DR. APOSTOLAKIS:  Because we lowered it by
           a factor of ten arbitrarily.  Right?
                       CHAIRMAN POWERS:  I mean, I don't know. 
           I mean, it seems to me --
                       DR. KRESS:  Must have had a reason for
                       CHAIRMAN POWERS:  Maybe it turns out that
           things are more susceptible to core damage. 
                       DR. KRESS:  Yeah.
                       DR. APOSTOLAKIS:  It's more than a factor
           of ten what you be now.  I mean there's a problem
           somewhere.  But anyway, it might be that that --
                       CHAIRMAN POWERS:  Factors of ten are not
           our of the question here.
                       DR. APOSTOLAKIS:  Now, you said some parts
           may be risk informed.  So you have decided that some
           parts may not be?
                       MS. CHATTERTON:  No.
                       DR. APOSTOLAKIS:  Okay.  Just a figure of
                       MS. CHATTERTON:  Yes, a figure of speech,
           but basically we're letting the industry propose how
           they want to handle -- how they think is the
           appropriate way and to provide a justification, and
           again this will go and do the review.
                       CHAIRMAN POWERS:  I guess, when you raise
           the issue of being risk informed, the challenge I see
           there has something to do with just what our
           discussion was.  We typically don't have a great deal
           of information on these fuels under accident
           conditions, severe accident conditions that will give
           you any consequence.  
                       Are you saying that the industry can come
           in, but they've got to come in armed with information
           on fuel behavior under accident conditions?
                       MS. CHATTERTON:  That might be an option
           if the proposal is to go that direction.  The main
           point is whatever method they decide to take, they
           have to provide the justification for why that's
           acceptable, with a great deal of emphasis on lead test
                       That's one thing that we have emphasized
           greatly in the last few years, I would say in the last
           five years, and that's a result of fuel issues that
           we've had in these last five or so years, and I'll be
           talking about some of those later, and the things that
           we've learned that the fuel -- the lead test
           assemblies in the past did not always give us data or
           information that was really the most useful.  
                       We've also said that a breath (phonetic)
           extension program will also have a fuel performance
           monitoring program.  Somebody said the fuel
           performance monitoring; that's in core.  I guess maybe
           it's really fuel surveillance program.  
                       DR. BONACA:  If you'd just stay with that
           slide, I would like to ask a question.
                       MS. CHATTERTON:  Sure. 
                       DR. BONACA:  Clearly, the first bullet I
           can see that you are concerned about how long the
           cycle is going to be or the burnup.  
                       MS. CHATTERTON:  Yes.
                       DR. BONACA:  And the issues that we
           discussed this morning.  At the bottom there, I see
           fuel performance monitoring program.  Now, currently,
           I mean, although it may be a concern to have fuel
           failures, the one percent for the fuel assumptions in
           analysis allow for 50 pins probably are going to be
                       Okay.  So I'm curious about what would
           this fuel performance monitoring program mean.  I
           mean, for example, some of the Westinghouse plans have
           exhibited at times maybe four or five 17's failed in
           some batches.  Okay.  That's really an operational
                       Is it also a regulatory concern right now? 
           Is that what it's focusing on?
                       MS. CHATTERTON:  This isn't focusing just
           on fuel failures.
                       DR. BONACA:  Yeah.
                       MS. CHATTERTON:  This is focusing on
           things like corrosion, growth.
                       DR. BONACA:  Okay.  I understand.
                       MS. CHATTERTON:  It's focusing on all the
           types of parameters that -- I want to characterize it
           fairly by saying in the past many times the fuel has
           been burned, taken out, put in the spent fuel pool,
           and never looked at.
                       DR. BONACA:  I understand.  
                       MS. CHATTERTON:  As a result we had some
           problems that might have been eliminated had the type
           of program that I'm talking about --
                       DR. BONACA:  So for example, oxidation
           rates because those also go in estimation of
           performance under accident conditions.
                       MS. CHATTERTON:  Yes.
                       DR. BONACA:  Okay.  I understand.
                       MS. CHATTERTON:  Yes.  And if you're not
           measuring your oxidation levels, you don't know if
           your inputs to your accident analysis are correct.
                       DR. BONACA:  Okay.  Thank you.
                       MS. CHATTERTON:  And that's the main point
           in that.
                       DR. CRONENBERG:  Margaret, on that, the
           NRC used to publish a fuel performance summary.  Every
           year PNL used to do the work.
                       MS. CHATTERTON:  Yes.
                       DR. CRONENBERG:  They used to summarize
           it.  That's no longer in effect.
                       MS. CHATTERTON:  That's correct.
                       DR. CRONENBERG:  Are you going to
           reinstitute this type of summary like the PNL used to
           do, but EPRI or industry or somebody will be -- will
           it be a formal, published monitoring program?
                       MS. CHATTERTON:  I don't think we're far
           enough along to really be able too say exactly how
           that's going to work.  How I envision when we will
           come up with a reg. guide will be it listing the types
           of testing that needs to be done, giving some ideas as
           to the frequency and when.
                       For instance, if you fuel goes beyond 62,
           but it's only to 63, and it's ten years down the line,
           it probably doesn't need to be measured again.
                       On the other hand, the different type of
           fuel, the slightly different power history, some of
           those, it's going to be difficult to come up with
           exactly how we handle this.  There's going to be a lot
           of thought into that such that it provides enough
           data, but it doesn't totally hamper the industry such
           that they have to measure everything because that's
           not the intent.
                       It's going to have to be set up with
           controls such that after so much data, there's not
           need.  If, on the other hand, if results aren't
           turning out to be good, then you need more.  And it's
           going to have to have triggers in it for when you do
           more results, when you do more testing and also when
           you would need to do a hot cell.  
                       Most of the hot cell exams, most of this
           is going to be pool site exams.  The types --
                       DR. BONACA:  That's what it was.  The PNL
           was mostly pool site exams.
                       MS. CHATTERTON:  Yes.  Oh, yes.
                       DR. BONACA:  But we don't have that data
                       MS. CHATTERTON:  We don't have that data
                       DR. BONACA:  I would hope that if you're
           going to push it to 70-75, that type of program goes
           on for a few years until you've had that --
                       MS. CHATTERTON:  Yes.  And that's the type
           of thing that I think we're thinking about.  Yes, I
           miss having those reports.
                       DR. BONACA:  Yeah.  
                       MS. CHATTERTON:  Those are great.  
                       DR. BONACA:  There was a lot of data.
                       MS. CHATTERTON:  Where are we in this
           whole plan?
                       Well, in the last year or so there's been
           some progress.  I would say not a tremendous amount. 
           Although the industry is working on it and it's slow,
           sometimes it comes in big steps.  
                       We had a draft submittal in March of 2000,
           and the staff provided comments, and we had another
           meeting with NEI December 6th.  They outlined their
           approach for RAA, and the staff gave them comments
           saying that it looked fairly reasonable.  
                       And basically what they're doing is
           proposing a clad failure and coolability limits that
           are a function of burnup.  They are based on enthalpy
           increase, and we've seen the preliminary work on this. 
           We haven't seen all the details; we haven't reviewed
           all the details.  
                       What they presented looks like a
           reasonable approach.  Again, one it's submitted we
           will do a complete review of it.  
                       We expect a submittal late summer.  Again,
           sometimes work takes much longer than they think. 
           Originally that was an early 2001 date, and it's been
                       CHAIRMAN POWERS:  If you get a submittal,
           say, in August, when do you think you'd have your
           review finished?
                       MS. CHATTERTON:  This submittal I expect
           in August will not be a complete submittal.  This will
           be a partial submittal and it will depend on the
           amount that's in it.  
                       I think a submittal like this is going to
           take us a considerable amount of time, six months or
           so I would say on half of it, possibly a year or more
           on the complete package.
                       If it comes in in pieces, which is I think
           the intention, we will kind of review it in pieces so
           that, one, we can get feedback that they're headed in
           the right direction in a given area.  But also so that
           we can keep the process moving.
                       There's going to be a lot of data needed,
           and some of this will be actually showing what data
           needs to be taken, needs to be obtained so that they
           can --
                       DR. BONACA:  Excuse me.  RIA stands for
           what, rod ejection accident?
                       MS. CHATTERTON:  Yes. 
                       DR. BONACA:  Okay.  
                       CHAIRMAN POWERS:  Reactivity insertion.
                       MS. CHATTERTON:  Right.  I'm sorry.  
                       DR. BONACA:  It's more general.
                       MS. CHATTERTON:  Well, I'm sorry.  Were
           there anymore questions on this one?
                       (No response.)
                       MS. CHATTERTON:  The next thing I wanted
           to get into a little bit was lead test assemblies just
           because, as I said, that's been an area that we really
           want some emphasis on, and we've stated all along that
           we think they should be prototypical, up to the
           proposed burnup with reasonable power histories that
           are similar to what's being used. 
                       In the past we'd always said we wanted
           them in very nonlimiting locations, and it was very
           common to burn a lead test assembly to 50 or 60
           gigawatt days, but to do it in six, seven cycles.  And
           then when you put the fuel in and burned it in three
           cycles, you may not get the same -- exactly the same
                       So that's why there's going to be a
           real -- we're really emphasizing lead test assemblies,
           and we also know the type of cladding makes a
           difference, the flow conditions, the water chemistry. 
           Lead test assemblies need to be characterized, of
           course, before irradiation.   
                       And they will need pool site, and or hot
           cell exams after.  Hot cells exams are probably going
           to be relatively infrequent, but there will be some
           need.  Certainly there'll be -- full site will be
           needed certainly after each cycle, final burnup on
           assemblies that are designated as lead test assemblies
           before they start irradiation.
                       However, there may be assemblies that
           become LTAs after they've had some burnup on them. 
           And so sort of to address that, to encourage lead test
           assemblies, to encourage the gathering of data, we've
           taken on a program to try to look for lead test
           assembly guidelines, something that we haven't had in
           the past. 
                       Sometimes we had a submittal that we
           reviewed and approved.  Many times there was not an
           actual regulation or any restriction.  So under the
           50.59, under the test parts they were able to do lead
           test assemblies.  It leads to a lot of things that we
           hope by coming out with some guidelines we can
                       The purpose, basically, to get a
           consistent approach, to get consistent database, to
           obtain data.  There's a real benefit to the industry,
           too, in that they will know what we expect and know
           that if they follow these guidelines, that it's
                       I'll give you the outline topics and
           things in another slide, but that's basically it. 
           We've made some progress on this.  We met with WOG in
           May of 2000.  They put a lot of work into it, got the
           whole industry together.  They submitted a topical
           report, which we looked at, and then we met with them
           in December.
                       We gave them our comments on that document
           in January, and we expect to hear from them again
           soon.  Some of the things that are covered and need to
           be covered is a definition.  Exactly what are we
           talking about as a lead test assemblies?  What are the
                        Characterization, the type of
           characterization of the rods, full site, hot cell;
           when are hot cell exams needed?
                       Characterization will have to address both
           pre-characterization and after final burnup.  
                       The guidelines will address the number of
           LTAs that can be in any one core.  Also the location. 
           That's what I mean by placement.  Location in the
           core, what restrictions we think are necessary.
                       Safety requirements.  The biggest thing
           here is in almost all cases the LTAs are designed such
           that they meet all the fuel design limits that the
           current core is meeting.
                       However, they meet them using a code
           that's been verified to 62.  If we're now talking
           about burnups that are going higher, we're taking a
           step in saying that the code is valid beyond.  
                       On the other hand, if you don't get the
           data you can't validate the code.  So this isn't an
           area that we're working on, how to write that up, how
           to address it such that it's covered conservatively.
                       Part of the way that it's covered, of
           course, is the few number of pins that would be LTAs
           and given the whole number in the core. 
                       DR. UHRIG:  There's been reports the last
           three or four years of a control rod binding and
           sticking, and the general, as I recall, the exposure
           was about 43-44,000 megawatt days per ton, in the
           vicinity of the assembly.
                       MS. CHATTERTON:  A little higher.
                       DR. UHRIG:  Little higher.  What's going
           to happen when you get the higher limits here?  Are
           there going to be more problems of that sort, or is
           this something that has been addressed?
                       MS. CHATTERTON:  That is one thing that
           will have to be addressed, and you're right.  I didn't
           have it on the slide.  But all the current type
           problems that we've seen, like the incomplete control
           rod insertion, some of these crud and oxidation type
           problems, all of those things are going to have to be
           addressed in a program to go to higher burnup,
                       CHAIRMAN POWERS:  When you think about it,
           people can go up to the 60 gigawatt days per ton. 
           Now, somebody comes along and says, "Gee, I want to go
           to 70."  That's what, 16 percent extrapolation?
                       It doesn't sound an outrageous
           extrapolation to me.  Do we have evidence that we
           would expect changes in physics of the kind we saw
           between going from 30 to 60 when we go from 60 to 75?
                       MS. CHATTERTON:  Do we have hard evidence?
                       I don't think we have evidence.
                       CHAIRMAN POWERS:  I mean, there are fuel
           rods around that have gone up to 75.
                       MS. CHATTERTON:  That's right.  There are
           fuel rods that have gone around.  I know of some in
           Europe that have gone as high as 100.
                       CHAIRMAN POWERS:  That's right.
                       MS. CHATTERTON:  Do we have evidence? 
                       No, we really don't.  But I think this is
           a point that the -- we said there was an extrapolation
           at one point in the past, and then there were some
           things that happened that maybe weren't thought were
           going to happen.  And that it's time to stop and
           really examine all the criteria before we move or
           leave forward.
                       CHAIRMAN POWERS:  I guess what I'm asking
           is -- I don't know whether I'm asking -- we're closing
           the barn door or we're making up for the sins of the
           past on the backs of the people that are guiltless. 
           And we're talking about relatively small changes here
           and asking for a heroic amount of work it looks to me. 
                       And I'm wondering is there really merit in
           that?  I mean if we sort out the issues in 60 and say,
           "Okay, everything's fine here," and that, quite
           frankly, looks the direction it's going with these
           superior clads.  You know, things look like they're
           moving along fine.  Do we really want to create an
           enormous burden?
                       I mean, clearly moving the lead test
           assemblies out of the benign locations and into more
           prototypical location, that's something that's been
           needed for a long time.  But after you go much beyond
           that, do we really learn risk significant information
           from LTAs?
                       MS. CHATTERTON:  I think we gain a good
           deal of information.  I think we also gain some
           confidence in reproducibility and uncertainty on --
           you know, how uncertain are the measurements to take
           when you take them only once?  You asked the question
           and --
                       CHAIRMAN POWERS:  Oh, yeah.  Ralph's good
           at that.  He knows how to do that.
                       MS. CHATTERTON:  And that is -- to me that
           is one of the things.  This is an opportunity that you
           have to do that.  That's not a difficult one.  You
           can't do that on the accidents that Ralph is talking
           about.  I mean, my goodness, the cost of the tests,
           you couldn't possibly do that.
                       But on this, these are some areas that you
                       CHAIRMAN POWERS:  There are those of us to
           take the vote that say you absolutely must do that,
           especially because of the test are so expensive.  
                       MS. CHATTERTON:  Well, I don't look at it
           as -- it sounds like a lot but let me -- maybe I
           didn't characterize some of it exactly correctly.  
                       I think there's a lot of areas that the
           industry is going to be able to right off very
                       CHAIRMAN POWERS:  Okay.
                       MS. CHATTERTON:  With the state -- going
           to higher burnup makes no difference and here's why.
                       We look at this, too, as this will help
           not only us, but the industry have a really good
           documentation of what is important and, you know, how
           things change.  
                       I expect there'll be an awful lot of
           things that are written off very quickly, and they do,
           too.  They're working on the major ones. 
                       DR. CRONENBERG:  Then maybe it's not so
           small.  It's longer burnup, higher burnup, longer fuel
           duty times, 20 percent power increases.  I thought you
           were asking a rhetorical question.
                       CHAIRMAN POWERS:  No, I don't think I was. 
           I agree with you.  Some of the things -- it's more
           than just an increment in burnup because we're doing
           an increment in --
                       DR. CRONENBERG:  I mean, Commonwealth
           Edison has come in on the docket with a 17 percent
           power increase, one step.
                       CHAIRMAN POWERS:  There's a lot more going
           on here, none of which is really designed to coddle
           the fuel at all.  It's going to put this fuel under
           some pretty heavy stress.  
                       But the question then comes back to is it
           a risk significant issue that we're getting into. 
           They can have all the operational difficulties that
           they want to volunteer for, and that's their business. 
           Is it -- what we're asking about are -- our concern is
           more with the risk issues.
                       And, you know, I think we have to be
           careful not to close the barn door and put the burden
           on --  that's all I'm concerned about.
                       MR. CARUSO:  I'd just like to make the
           observation -- this is Ralph Caruso from Reactor
           Systems Branch.  
                       Dr. Powers, you had asked if there was a
           regulatory requirement for us to gather this sort of
           operational data, and I would make the observation
           that we are less interested from a regulatory point of
           view in this operational data than in the knowledge
           point of view. 
                       One of the reasons why we're encouraging
           people to do lead test assemblies is to share the data
           with us.  In the past they've been reluctant to do
           that, but what we're trying to do is we're trying to
           make the process easier for them so that they can do
           more testing which we believe benefits them.
                       And by trying to make the process easier
           and being a bit less threatening from a regulatory
           perspective, we hope that they'll share the
           information with us.  We'll understand what they're
           doing, and we will therefor feel more confident that
           they know what they're doing.  
                       So there's quite a bit of working together
           on this, and we're not necessarily going to change any
           regulations.  We're just trying to understand what's
           going on.  I don't know if that helps any.
                       CHAIRMAN POWERS:  Sure.  
                       DR. KRESS:  I see two places where
           operational testing could shed light on or that has
           risk significance.  One of them is on the rod
           insertion issue. 
                       And the other one is that it's true that
           the iodine spike is due to failed pins, which are few
           and far between in a core, but that may be where
           that's -- may be where that spike comes from.  I would
           perceive that if higher burnup increases the failure
           rate of those pins, it would increase the iodine
           spike, and you might be able to see that during the
           operational -- that's where it comes from anyway --
           during your operational observations.
                       CHAIRMAN POWERS:  You've got to convince
           me that an iodine spike is risk significant.
                       DR. KRESS:  Yeah, it falls more in the
           category of design basis accidents.
                       CHAIRMAN POWERS:  Design basis accidents. 
           I mean I think there are risk -- there are interesting
           risk significant features here in the high burnup
           fuels.  I'm not sure that LPAs get to them.
                       DR. KRESS:  Yeah, that's -- I think that
           was your point.
                       CHAIRMAN POWERS:  Yeah.
                       MS. CHATTERTON:  The LTAs do provide you
           with the rods you need for something like Ralph's
           program and for really --
                       CHAIRMAN POWERS:  Now, there's where you
           get it.  Now, Ralph's program's got to be extended to
           75 gigawatt days per ton; right, Ralph?
                       MS. CHATTERTON:  Actually, we've said the
           industry has to then pick up the tab beyond 62. 
           That's as far as the agency program.  We said we do
           confirmatory work to 62 and then beyond that --
                       CHAIRMAN POWERS:  I know what you said. 
           Now, we just won't hold you to it.  We'll let you
           backtrack on that one.  
                       MS. CHATTERTON:  The last point on my lead
           test assembly guidelines thing is we don't have
           reporting in there.  Basically, hopefully it would be
           a template.  It would be very easy to fill out, but it
           would give us -- it would provide the data.  Then we
           would be able to know exactly what's happening with
                       CHAIRMAN POWERS:  Nothing that you are
           legally bound to is easy to fill out.  
                       MS. CHATTERTON:  I just finished my taxes.
                       CHAIRMAN POWERS:  That's right.
                       DR. CRONENBERG:  You know somebody was --
           that wasn't very expensive, that annual -- that kind
           of pool site inspections, and I think it was a good
           thing, and we don't do it any more.  
                       CHAIRMAN POWERS:  Yeah, I mean there's not
           question it's a good thing, but the idea that a
           licensee is going to have an easy report to fill out,
           I mean, it just doesn't exist.  There is no report
           that the licensee prepares that's easy to do, because 
           they are --
                       MS. CHATTERTON:  Easier?
                       CHAIRMAN POWERS:  Easier is possible.
                       MS. CHATTERTON:  Okay, easier. 
                       DR. UHRIG:  What happens to the lead test
           assemblies?  Do they remain with the utilities?
                       MS. CHATTERTON:  Yes.
                       DR. UHRIG:  And are they usually sent for
           examination in detail or is this just sort of a --
           what kind of data comes out of them?
                       MS. CHATTERTON:  At the end, we would
           expect an all lead test assemblies to do pool site
           exams, and that --
                       DR. UHRIG:  Okay.
                       MS. CHATTERTON:  -- that would consist of
           oxidation measurements, probably growth
           measurements --
                       DR. UHRIG:  Growth rate, yeah.
                       MS. CHATTERTON:  -- growth rate, visuals,
           get an awful lot from visuals.  And then depending on
           if anything was found, it would determine what
           further --
                       DR. UHRIG:  They don't do a destructive
           examination though.  Metallurgy --
                       MS. CHATTERTON:  No.  If something really
           is shown, then we would think that a hot cell exam --
                       DR. UHRIG:  Would be in order.
                       MS. CHATTERTON:  A constructive hot cell
           exam would be in order. 
                       CHAIRMAN POWERS:  How many cells in the
           country are available to do full length rods?
                       DR. UHRIG:  One.  Two.
                       CHAIRMAN POWERS:  Two.
                       MS. CHATTERTON:  Yeah.  A number of hot
           cell exams, few and far between.  
                       So moving on, why do we really want a lot
           of that?
                       Well, part of it is because of some of
           these recent fuel issues.  Oxidation higher than
           predicted.  We have several cases where, as I said,
           the LTAs behave beautifully.  If the fuel is burned as
           the LTAs were, it behaves beautifully.  But if it's
           burned at a higher rate, at faster duty, they've
           gotten very different results. 
                       I think you're all probably aware of axial
           offset anomalies that still tend to be -- that's a
           problem that's still not completely understood.  
                       DR. UHRIG:  Isn't that pretty much boron
                       MS. CHATTERTON:  It's a chemistry issue,
           but it's also a fuel duty issue.  And it's a very
           strange --
                       DR. UHRIG:  Well, it does depress the flux
           in the area and reduces the load on the fuel.
                       MS. CHATTERTON:  That's correct.
                       DR. UHRIG:  But it would force it to be
           somewhere else for the same power level.
                       MS. CHATTERTON:  Yes, it forces -- it's
           usually the precipitate at the top of the fuel forcing
           the power to the bottom.  You end up with a shutdown
           margin problem.  Had one utility that had to operate
           at 70 percent power for four of five months as a
           result of that, and it's continued through other
                       Several other utilities have seen it, not
           anywhere near to that extent.  
                       DR. UHRIG:  This is --
                       CHAIRMAN POWERS:  Do we understand -- I
           mean this is an inverse chemistry thing.  Inverse
           solubility issue, and you don't ordinarily think of
           that arising with boron.  Do we understand why boron
           suddenly has an inverse -- boron becomes less soluble
           at high temperatures.
                       MS. CHATTERTON:  Actually, it's a sub-
           cooled boiling.  Basically, what you've done is you've
           precipitated some crud onto the control rods, you're
           in a region of sub-cooled boiling, and in the process
           of sub-cool boiling with the boron, you precipitate
           boron into that crud.  
                       CHAIRMAN POWERS:  And that's the step I
           don't follow.
                       MS. CHATTERTON:  You don't follow.
                       CHAIRMAN POWERS:  Why does the boron
           suddenly say, "I want to precipitate"?
                       MS. CHATTERTON:  Well, with the sub-cooled
           boiling you've got a mechanism there to -- you want to
           give me a little --      
                       MR. NISSLEY:  I'm not an expert on this
           but some of the theories are that when you have crud
           and corrosion in the presence of sub-cooled boiling,
           that the boiling mechanism is coming off as pure steam
           and leaving the boron behind. 
                       CHAIRMAN POWERS:  And then it gets flooded
           right back up with water and --         
                       MR. NISSLEY:  It's thought to -- it's
           sometime referred to as boron hide-out where it's not
           on the -- completely on the outer surface.  It's
           somewhat within the structure of the crud and the
                       MS. CHATTERTON:  You get kind of like
           little chimneys in within the --
                       CHAIRMAN POWERS:  This sounds like on of
           the things that if you tried to do it, it would be
                       MS. CHATTERTON:  Probably so.  But it's
           certainly been a problem that --
                       DR. CRONENBERG:  But it's real.  I mean,
           they've measured crud with a high boron content.  
                       MS. CHATTERTON:  Yes.
                       CHAIRMAN POWERS:  Well, I'm still asking
                       DR. CRONENBERG:  Yeah, I don't know, but
           it's there.
                       MS. CHATTERTON:  Everyone has spent a lot
           of time on this issue, and it's still around.  We've
           had some fuel failures in a couple different plants
           due to high fuel duty.  Again, a combination of crud
           and high fuel duty.  
                       In all these cases, we've seen the effects
           of water chemistry, high crud build-up, and we've seen
           some accelerated growth of rods in assemblies.
                       That's much more the IRI issue that is
           pretty much under control.  I think I could say that
           very easily in all plants, or at least appears to be
           up until very recently.  
                       The last thing I wanted to talk a little
           bit about is some of the current fuel reviews that
           we're doing.  We have two reviews on cladding types
           that are in house now.  One is the duplex cladding
           developed by Siemans, used extensively in Europe. 
           That's the one that has rods up to 100 in the Goesgen
           plant in Switzerland.
                       CHAIRMAN POWERS:  Wow.
                       MS. CHATTERTON:  The review on that
           cladding will be to 62.  And we're just beginning that
           review right now.  
                       We're also reviewing the use of ZIRLO for
           CE plants.  We have some CE plants that have fairly
           high duty that have been using a low tin Zircaloy
           that's not been standing up to quite what they would
                       And so the use of ZIRLO in those plants
           would be extremely advantageous.  And that's the
           reason the timetable is they really want this by the
           end of the summer.  So we've got a large review.  
                       The issue is basically a lot of it will be
           making sure that the interfaces are done correctly on
           the computer codes, that you get the right properties
           in, and it's handled in each way.  So there's a lot in
                       And basically that's what I had as far as
                       DR. UHRIG:  What do you mean by duplex
                       MS. CHATTERTON:  Duplex is -- it's a
           double type of cladding.  It's almost the reverse of
           the BWR liner cladding.  
                       DR. APOSTOLAKIS:  The barrier cladding.
                       MS. CHATTERTON:  It's got its corrosion
           barrier on the outside, and it's a Zircaloy on the
                       DR. APOSTOLAKIS:  Okay.  It's a double
                       MS. CHATTERTON:  It's essentially a double
           cladding.  Very, very --
                       DR. UHRIG:  They're both Zirc?
                       MS. CHATTERTON:  Pardon?
                       DR. UHRIG:  Both are Zirc?
                       MS. CHATTERTON:  No.  
                       DR. APOSTOLAKIS:  Different material.
                       MS. CHATTERTON:  The outside is a -- I
           have to think.
                       PARTICIPANT:  It's a proprietary material
           to Siemans.
                       MS. CHATTERTON:  Yeah.  
                       DR. UHRIG:  Oh, okay.  
                       MS. CHATTERTON:  The strength part, inner
           part is Zirc-4.  And as I said, they've had -- they've
           used that extensively in Europe.  The data from it as
           far as corrosion and performance is absolutely
                       CHAIRMAN POWERS:  I hope that once you get
           through your duplex cladding review, you come down and
           talk to us a little bit about that. 
                       MS. CHATTERTON:  Sure.
                       CHAIRMAN POWERS:  Because I think that
           would be interesting for us to see. 
                       MS. CHATTERTON:  Good.  Thank you very
                       CHAIRMAN POWERS:  Thank you, and good luck
           in Boston.  
                       MS. CHATTERTON:  Oh, thank you.  It'll be
           a slow run.  It will be fun, but it won't be a fast
                       CHAIRMAN POWERS:  Don't care how slow it
           is.  the fact that you're there is just amazing. 
                       DR. KRESS:  We're going to look for you on
                       CHAIRMAN POWERS:  We'll watch for you on
                       MS. CHATTERTON:  I'll be the last one.
                       CHAIRMAN POWERS:  We're going to switch
           gears and Dr. Lee fresh from a vacation of over --
           almost a week duration in Italy is obviously going to
           be in fantastic spirits to talk to us about the MOX
           research program.  
                       Yes, you're in a good mood when you come
                       DR. LEE:  I'd like to briefly tell you
           something about the MOX research that Office of
           Research undertook, just started last November.
                       How about now?  Thank you.
                       And you know why our interest in mixed
           oxide fuel.  In February 2nd, the NMSS team came
           before the full Committee and briefed you on the
           certification plan and what is the activity related to
           your mixed oxide fuel, MOX fuel use in U.S.  That is
           basically the disposal of up to 33 metric tons of MOX
           fuel in using it in our commercial reactors, and the
           two plan, four units targeted is McGuire and Catawba.
                       CHAIRMAN POWERS:  What I have never
           understood is why ice condenser plants are
           particularly  suited for using MOX fuel.
                       DR. LEE:  And you were told that they
           really did not target ice condenser, remember?
                       DR. LEE:  There was two Virginia power
           plants that was involved with it, but they drop out of
           it, but it happened in the two plants that's left. 
           There are four units left now, ice condenser plant,
           under Duke Power, and I'm sure your concern has to do
           with the severe accident issues about fuel dispersal.
                       CHAIRMAN POWERS:  Yep.  Comes to mind.
                       DR. LEE:  I think, one, we did the DCH for
           ice condenser plan.  We found the McGuire plant is
           slight a bit higher than the cutoff point that we use,
           like .1 conditional failure probability.  It came up
           to .14, but the Duke Power took issue with us that if
           you take into the real design of the plants, that
           number will come down.
                       So when the whole overall evaluation for
           MOX use in the McGuire come in, those numbers will
           be --
                       CHAIRMAN POWERS:  Yeah, I think I would
           have responded by saying, "Yeah, and when I take the
           degradation of the containment into account, the
           number goes up again."
                       DR. LEE:  Well, the research activities
           really focus on supporting a user request that came in
           back in late '99, and at that time we didn't have any
           budget to address it, but we just had budget this year
           to address the technical assistance requested by the
           regulations, nuclear reactor regulations.
                       They are interiors (phonetic) neutronics,
           fuel and source terms.  The neutronics, they want to
           modify the codes that were used for MOX and also, of
           course, goes with it all the fuel behavior, monitoring
           assessment for the fuel behavior for design based
           accidents and under normal as well as design based
           accidents need to be corrected before we can use it.
                       And then in the source term area that we
           also need to validate that the source term that we
           used for UO-2 fuel (phonetic) is approximate for MOX.
                       DR. KRESS:  How much, what percentage of
           the fuel would be MOX in these?
                       DR. LEE:  It's normally one third of the
           core would be MOX.
                       DR. KRESS:  Oh, as much as one third?
                       DR. LEE:  Yeah.
                       DR. KRESS:  Okay.  I --
                       PARTICIPANT:  Forty percent.
                       DR. KRESS:  Okay.
                       DR. LEE:  Or even more than that.  Thirty
           to 40 percent.
                       Now, as I mentioned to you, we started
           this activity not too long ago, but at that same time
           before that, Ralph Meyer was doing a PIRT on the high
           burnup fuel.  So since we know the MOX is going to be
           coming into play, we attached to ask our experts to
           tell us something about what do we have to do for the
           LOCA and reactivity accident, and that PIRT has been
                       And on that Web site you will see the
           reports related to LOCA as well as the RIA accident. 
                       The source term PIRT now is going to be
           starting very soon.  It's not just for MOX.  It's also
           for high burnup fuel as well, and we expect to finish
           by this year.
                       The composition for the experts have not
           been -- selection not been completed because we're
           waiting for a response from French and from Japan and
           also from the industry selecting experts to
           participate in this panel.
                       The NRC internal one has suggested some
           members, and we're working on that.
                       Now, in the neutronics area, there are
           three areas that we have initiated.  The first one is
           the PARCS code that we have at Purdue University. 
           That has been used for many years.  This PARCS code is
           a neutronics code being interfaced with our thermal
           hydraulics codes like TRACK M or RELAP, and we have
           used it, and we have used it very successfully for RIA
           type analysis.
                       And we initiated the modification for this
           to make it more usable for MOX.  That is started in
           November, when we initiated these activities.
                       At this time, we extended the number of
           group of energy that can be handled by the code from
           two groups to n group because it's very easy to make
           it general.  One time we can use seven groups, four
           groups, two groups, because if the industry comes in
           with analysis with two groups, we have to be able to
           collapse it to two groups so we can analyze it on the
           same base.
                       The cross-section because of the isotropic
           between the UO-2 bundles and the MOX bundles, there
           will be very sharp gradients of neutron flux.  So we
           have to handle the scattering correctly.  So we have
           expanded the cross-section angle of dependency with P3
           approximation.  That has been completed as well at
           this time.
                       DR. APOSTOLAKIS:  Is there a report where
           I could go and find more about these observations
           like, you know, why you need to go to the P3
           approximation, and so on?  The motivation for the
           research, in other words.
                       DR. LEE:  I think the motivation if you
           look at the Europeans, the way they analyzed the MOX
           code, they usually use a high order scattering to do
           the approximation.
                       DR. APOSTOLAKIS:  So I should look to
           Italy as well to find that?
                       CHAIRMAN POWERS:  Well, I think there's --
                       DR. APOSTOLAKIS:  There must be a report
                       CHAIRMAN POWERS:  Yeah, one of the authors
           of PARCS put out a document that went through all of
           these things, and it was given to this subcommittee a
           couple of years ago, I guess.  I can't remember the
           exact title, and I mean, I am sure we could find that
           for you.
                       DR. APOSTOLAKIS:  Okay.
                       DR. KRESS:  It was a pretty good document
           as best I remember.
                       CHAIRMAN POWERS:  It was a pretty good
           document.  I mean, it raised the scattering and the
           group issue.  It also raised the delayed neutron
           fraction issue.
                       DR. LEE:  Yeah, the delayed neutron
                       DR. MEYER:  Was this a Commission paper
           that you're referring to?
                       CHAIRMAN POWERS:  No, no.  Actually it was
           a Purdue report.
                       PARTICIPANT:  It was critical, a bit
           critical, right?
                       CHAIRMAN POWERS:  Well, I wouldn't say it
           was critical.  I would say that he came back and said,
           "Look.  My PARCS code right now can't do the MOX fuel
           because of these things," and he listed down what he
           had problems with using PARCS for that.
                       So I mean if it was critical, it was
           critical of his own codes.
                       MS. SHOOP:  This is Undine Shoop with
           Reactor Systems.
                       You can find more detail in the Commission
           paper that we wrote.  We've authored two of them at
           this point.  One would be from '99, and one would be
           early 2000, and I'm sure we can get copies of them for
                       DR. APOSTOLAKIS:  Good.
                       DR. LEE:  In addition, at this time there
           was a researcher from Saclay, is stationed at Purdue
           University assay change for about a year, and you can
           reduce in the French code CRONOS, and this code has
           been benchmarked against many of othe plant data in
           France that use MOX code.  So we like to compare that
           with the developed PARCS that we're going to be using
           for MOX code analysis as well.
                       Tom Downer from Purdue University is the
           one who is the PI for this, principal investigator for
           this work.  He's also working with the OECD and NEA to
           develop a theoretical benchmark for reactivity
           transient.  This is quite a lot of work to do because
           now you need to develop an exercise that go from
           steady state and looking at some transient, how would
           the parts compare with other codes?
                       Of course, you would be using a Monte
           Carlo code calculation, and so forth, but this is a
           code-to-code comparison.
                       We also initiated a very small activities
           at Brookhaven under Dave Diamond.  He has been helping
           us for many years, helping us to do independent
           assessment of PARCS, and we intend to use him to
           continue this activity.
                       It provides feedback to code developers,
           and we try to make it also more user friendly, too,
           because a couple in between the milars (phonetic)
           continue to be a problems in setting up the problem,
           but we are making it better now.
                       And then also, in terms of if there is any
           technical issues that we require his assistance to
           review, the licensee will submit to us and we will ask
           them to do so.
                       At the same time we also initiate a
           lattice physics code develop at Oak Ridge.  It's a
           routine called NEWT, and this is part of the scale
           code, the whole suite of codes that Oak Ridge use for
           shielding, heating, decay heat, and also analysis.
                       And this will enable us to generate the
           cross-section, assembly-wise cross-section that we can
           feed into PARCS and that PARCS can use for steady
           state, and as well sa depletion, as well as transient
           analysis, especially IA type.
                       In the fuel area, of course, we started to
           update the material properties for the FRAPTRON and
           the FRAPTRON codes to be used for the MOX analysis. 
           Then, of course, we have to assess the experiment
           against data.
                       There is a Halden exercise, blind test,
           the CS&I test completed, and at that -- actually the
           rig is still inside the reactor.  They continue to
           monitor, measure the build-up of the fission gas, and
           the temperature.  So you can get those probably as a
           function of burnup.
                       The exercise they did was allow 14
           gigawatt days per ton.  At that point they asked all
           the participants to do the calculations.  That was
           back two years ago, and they just finished that.
                       So those are the information that we would
           like to revisit, and of course, in this area, I didn't
           mention, of course, the Cabri test for the IRA.  We
           would like to look at the gigawatt behavior, as well.
                       In the source term area, we are
           negotiating with the France to get VERCORS
           experiments.  The VEGA from Japan, they will not be
           doing any MOX experiment until like 2003.
                       There's some tests that has been done
           already in VERCORS in France, up to like 41 gigawatt
           days per ton.  It's about three pallets only, and they
           are also starting a new facility in Cadarache that we
           don't know much about, but this one will have a longer
           length rod, about maybe 60 -- six centimeters long.
                       And we don't know what the test matrix
           look like in terms of when the MOX test will be coming
           in because this facility is supposed to replace this
           town in the near future.  So they will shut down all
           of the hot cells and those type experiments at
           Grenoble in France, and then, of course, research will
           assist licensing in terms of review any technical
           issues that will be rising.
                       DR. MEYER:  Could I add something here?
                       DR. LEE:  Yes.
                       DR. MEYER:  It's Ralph over here.
                       I didn't seen Cabri on your slide, but
           there are two MOX tests in the Cabri water loop, and
           there have been.  Did you have that?  I'm sorry if you
           had it on there.
                       DR. LEE:  No, I didn't put it in here.  I
           mentioned it in here that we need.
                       DR. MEYER:  Oh, okay.
                       DR. LEE:  I didn't put that on here.
                       So our activities just started not too
           long ago.  So we don't have any results to tell you,
           but on the source term area, next year, this coming
           fiscal year, we will start to initiate the validation
           for the codes that are going to be used for source
           term analysis, and that's the first one we're going to
                       CHAIRMAN POWERS:  When is an appropriate
           time for us to hear about what you're doing with
                       DR. LEE:  I think by May time he will be
           able to do some demonstration on using the type of
           analysis that he has.
                       CHAIRMAN POWERS:  So maybe some time in
           the fall?
                       DR. LEE:  Some time in the fall, yes.
                       CHAIRMAN POWERS:  Yeah, I think the
           Committee would be --
                       DR. LEE:  -- MOX calculation was the
           difference between UO-2 versus MOX.
                       CHAIRMAN POWERS:  I think it's been a long
           time since the Committee has looked at some of these
           neutronic things, and since it's an important part of
           TRACK M maybe the Fuel Committee and the Thermal
           Hydraulics Committee might want to get together and
           just focus on that, say, for half a day, just that
           particular topic.
                       MR. ROSENTHAL:  Because we're using this
           also just plain the UO-2 RIA issues.
                       CHAIRMAN POWERS:  Sure, yeah.  I mean,
           it's a fairly important code.
                       MR. ROSENTHAL:  Sure.
                       CHAIRMAN POWERS:  I like the way you guys
           went about selecting to use it and whatnot.  I thought
           that was a very analytic process, but when it came in,
           there was this list of challenges I would say in
           interfacing and shortcomings that the code had for
           modern things, and it would be nice to see how it all
           came out.
                       DR. MEYER:  By the way, we had a small
           task in our program with Kurchatov Institute with IPSN
           involvement as well to do some MOX calculations for
           the reactivity transients.
                       MR. ROSENTHAL:  And that's really good
           because everything we have traces back to NDEF
           (phonetic), you know, NDEF E6 or 7, and that's
                       Can I just make a summary statement?  And
           that is that I'm relatively new in the current branch,
           just a little bit over a month, and so I go to Richard
           and I go to Ralph all the time.  In fact, Ralph's
           office is next to mine.
                       And we were talking, and I think it's
           important to make the following point.  If I go to the
           RIA, okay, what we ultimately will discover is that
           the speed limit that we thought was appropriate for
           decades is probably incorrect and, you know, maybe 280
           becomes 100 or 80, some other number, and at the same
           time when we do 3D space-time kinetics, we're pretty
           comfortable that people will be able to demonstrate
           that they can live with a revised lower speed limit. 
           So you don't have a big safety issue, having done all
           that work and recognized that.
                       And I said, "Yeah, but shouldn't this give
           us some humility?"
                       MR. ROSENTHAL:  Okay?  That here was
           something that, you know, we thought of and didn't
           question, and now we have a different perception.
                       And if it's giving us some humility with
           respect to the enthalpy deposition, then it's fair to
           say, well, what other surprises are there in stock for
           us as we go to high burnup or new alloys or your MOX,
           and that sense of, well, what other surprises are in
           stock for us, and maybe a little humility, leads us
           to, in fact, fund fuel work and research as a truly
           sensible fraction of the total research budget.
                       I just wanted to leave you with that.
                       DR. APOSTOLAKIS:  Now, the view for
           McGuire and Catawba, are these considered changes in
           the licensing basis, the use of MOX?
                       DR. LEE:  Sure, sure.  It would have to
                       DR. APOSTOLAKIS:  So what if someone --
                       DR. LEE:  Specific licensee.
                       DR. APOSTOLAKIS:  What if someone decided
           to use regulatory guide 174 to argue for or against?
                       DR. LEE:  I think the same question would
           arise, that phrase when Margaret was asked about
                       DR. APOSTOLAKIS:  The question will arise,
           but --
                       DR. LEE:  Yes.
                       DR. APOSTOLAKIS:  -- it says here MOX
           research, and I don't hear you doing anything about
           it.  Why aren't you looking into it?
                       DR. LEE:  I think that is up to the plant,
           what they want to do it under the regular 1.1 -- 1.7.
                       CHAIRMAN POWERS:  I guess I'm confused,
           George.  I mean, if the program includes an
           examination of the source term, and so I'm a little
           questioned -- I mean, maybe you can say there's some
           core degradation work that --
                       DR. APOSTOLAKIS:  If Tom is right and the
           left values are not the right ones, you have to modify
           them.  Shouldn't somebody look into that?  Does that
           come naturally from this?
                       CHAIRMAN POWERS:  Yes.  I mean, that would
           be the whole point.  If somebody came back and said,
           "Look.  This" --
                       DR. APOSTOLAKIS:  What does that -- point
           to me to that.
                       CHAIRMAN POWERS:  If the source term is
           going to be different from that, then once you had
           that, that's when you would have to reexamine your
           derivation to get from the quantitative health
           objectives to get to the acceptance value of worth.
                       DR. KRESS:  They're putting together a
           PIRT now just to look at that.  You know, they don't
           define the program yet.  They just want to say what
           are the likely phenomena; what are the issues; what
           research should we do.
                       DR. LEE:  The source term PIRT is that
           we're going to look into what are the issues that we
           have to deal with for NUREG 1465.  What do we need to
           do for that for MOX.
                       And then in the model developments, we're
           going to validate our models.  We're going to use --
           for example, I'm going to take a core, and I'm going
           to have an analysis of all uranium fuel assemblies,
           analyze and look at inventories, and I'm going to take
           another core which is one third or 40 percent loaded
           with MOX, and I look at the two source, and I will do
           my consequent analysis, and I would like to compare
           what are the consequence, what are the difference from
                       Now my mother has to be validated
                       DR. APOSTOLAKIS:  Now, when you say do
           your consequence analysis, what do you mean?
                       DR. KRESS:  There's a design basis space
           he's talking about.
                       DR. LEE:  For the design.
                       DR. KRESS:  Chapter 15.
                       DR. APOSTOLAKIS:  But LERF was not
                       DR. KRESS:  No, no.  He'll have to do more
           than 1465 --
                       DR. APOSTOLAKIS:  Yeah.
                       DR. KRESS:  -- to get to that stage. 
           They'll have to have more detailed fission product,
           release models, and --
                       MS. SHOOP:  This is Undine again.
                       I would just like to add that as part of
           our user need memo we have requested the Office of
           Research to look not only into the source term, but
           how that will impact the different levels of the PRA,
           and I believe that right now that's being looked into,
           and I'm sure that when Richard comes back here to talk
           about our further research in the future after we're
           done with the source term, then we'll be able to go
           into more detail on the additional research we're
                       CHAIRMAN POWERS:  Okay.
                       DR. LEE:  Oh, Dana, one thing that I think
           we should also know, that the French is launching a
           PHOEBUS 2K (phonetic), which also has a MOX component
           in it, and they want to look at is there any sudden
           core degradation phenomenon that we don't know about
           that is vastly different between UO-2 versus MOX.
                       And also in the LOCA arena, they are also
           looking into doing LOCA as a series of looking at the
           loss of cooling accident for high burnup fuel, but I
           don't know whether MOX is included in that.
                       CHAIRMAN POWERS:  They're going to have to
           jerk their driver core here pretty soon, aren't they?
                       DR. LEE:  Yes.
                       CHAIRMAN POWERS:  Now maybe they're going
           to run out of oomph in the driver core.
                       DR. LEE:  I think they need to refurbish
           that entire thing.  The driver core is only good for
           the current series of tests, and after that they
           completely have to refuel the whole driver core for
           the following improvement.
                       CHAIRMAN POWERS:  So there will be an
           examination of the core degradation aspects.
                       DR. LEE:  That's what they would like to
           do, yes.
                       CHAIRMAN POWERS:  Right.  Any other
           questions of the speaker?
                       (No response.)
                       CHAIRMAN POWERS:  Okay.  We have a treat. 
           Dr. Lyman from the Nuclear Control Institute is here
           with us again.  Dr. Lyman has spoken to us before. 
           He'd like to have a word with us.
                       He didn't tell me what he was going to
           talk about, but I'll bet it's on MOX fuel.
                       DR. LYMAN:  Thank you.
                       CHAIRMAN POWERS:  Put it on your tie
           probably is a better --
                       DR. LYMAN:  How's that?
                       CHAIRMAN POWERS:  Yeah.
                       DR. LYMAN:  Okay.  Well, you're right. 
           Since the top was MOX fuel and that's one of the main
           concerns of my organization, the Nuclear Control
           Institute, so I thought it might be a good time to
           come back.
                       Actually I've never spoken to the ACRS
           before on MOX.  Two years ago I gave a briefing to
           interested NRC staff on a study I had done, a
           preliminary study which was actually a consequence
           assessment, exactly what was just being discussed, of
           the use of MOX fuel in light water reactors and
           actually a regulatory guide 1.174 approach to how you
           might risk inform the use of MOX fuel.
                       And so I'd like to actually go over those
           again.  I've since refined the report, and it's going
           to be published.  I wish I had a final version.  This
           is a penultimate version, and it should be available
           very soon in the Journal of Science and Global
           Security, which comes out of Princeton University, and
           it will be on their Web site.
                       So as soon as that's out, I'd be happy to
           point people to it if they're interested.
                       Okay.  The title of my talk is "MOX Fuel
           Safety, a Need for Research," and I'm very  glad that
           there's finally money in the NRC budget for doing some
           MOX research since there hasn't been for a long time,
           even though this program has been coming for a while.
                       My organization has been very concerned
           about the way the Department of Energy has dealt with
           the issue of MOX fuel.  From the beginning, their
           environmental analysis, the whole way in which they
           made decisions regarding weapons plutonium disposition
           without really looking hard at some of the safety
           issues that were going to be coming down the pike with
                       I wish they'd involved the NRC earlier,
           and there is still time to deal with these issues, but
           it's starting to run out.
                       So just briefly I'd like to give some of
           the overall, the general concerns I have with the way
           the MOX program is evolving, including some very
           recent developments, and then I'd like to talk about
           some of the detailed safety issues that I think are of
           concern in this program.
                       One is the issue of the source term impact
           on severe accident consequences and risk, and then the
           impact on transience, including the over cooling
           accident, pressurized thermal shock, and then RIAs,
           and then finally some troubling issues concerning the
           MOX qualification plan which has been laid out by the
           licensee, Duke, Cogeme (phonetic) with Stone &
           Webster, or DCS.
                       So starting with the MOX program concerns,
           I think the question came up before why are ice
           condenser plants the best suited for using MOX fuel,
           and the answer is they are the only ones that are
           willing to do it.  There was no real choice for the
           mission reactors.  There was no real competitive bid
           that was worth anything.  There were only three
           consortia that competed.  Two of them didn't even meet
           the basic requirements.  So they were eliminated right
           off the bat, leaving on the Duke Power consortium,
           which originally had Virginia Power.  They dropped
           out, I believe, because they would have had to modify
           their control rod systems in North Anna, and they
           didn't want to do that.
                       So for better or for worse, we're stuck
           with the ice condensers, and I'll talk about our
           concerns about that a little later.
                       The second great concern we have with the
           MOX program is the fact that the timetable is dictated
           by international agreement and not by safety
           requirements.  The U.S. and Russia signed an agreement
           last fall or late last summer that commits both sides
           to starting to use MOX fuel in light water reactors by
           the end of 2007, and our concern, of course, is
           because of the political pressure, because this is a
           nonproliferation program, that NRC is going to have a
           very hard time raising substantive issues that might
           cause delays in the schedule, and they run the risk of
           being accused of being obstructionist and interfering
           with important nonproliferation programs.
                       And so I feel this is a potential tension
           that might influence the ability of NRC to do a fair
           assessment of MOX safety issues.
                       Related to this are the DOE budget cuts
           which are impending.  The MOX program apparently,
           according to news reports, is not going to get the
           increases that it expected under a potential Gore
           administration, since it was Gore who was shepherding
           the bilateral plutonium disposition talks.
                       And the fact is that a reduction in budget
           for MOX is only going to increase pressure that any
           safety review for MOX be abbreviated, and that there
           will be less DOE resources available for helping NRC
           to resolve some of these technical issues.
                       This could lead to heavy reliance on
           proprietary foreign data, which for many reasons our
           organization doesn't think is going to be appropriate
           or adequate for resolving the issue of MOX use in U.S.
                       And finally, the impending cancellation of
           the other plutonium disposition track, which was a
           mobilization of plutonium in a ceramic and disposal of
           high level waste, this program apparently is being
           zeroed out by the Bush administration, and that means
           that there will be at least an additional eight and a
           half tons of plutonium which will be heading toward
           the MOX program for disposition in roughly the same
           time period, and it's not clear how DOE is going to
           address that at that point, but again, it will
           increase the burden on MOX as the only route for
           achieving disposition.
                       So with those political pressure in mind,
           I'd just like to review some of our concerns about the
           safety of MOX, and the biggest contributor I think to
           the enhanced risk of using MOX in light water reactors
           is the additional source term that comes mainly from
           an increased transuranic inventory in the core.
                       Now, according to the calculations that I
           did using the scale code, you find for the DCS core,
           which has a 40 percent MOX core fraction and an
           aqueous processing which will remove the americium
           that's been building up in the plutonium pits since
           they were last recycled; that if you remove the
           americium, then at end of cycle I find that you'll
           have about two times more of the isotopes like
           Plutonium 239, Americium 241, Curium 242.
                       Plutonium 238 is a little bit less, but
           that doesn't have a big safety impact, and also, since
           I know the Committee has been interested in ruthenium
           lately, incidentally, for a given MOX assembly you
           have more than twice the amount of Ruthenium 106.  So
           an average of the core and into cycle, I find you have
           about 45 percent more Ruthenium 106, which might play
           a role in events where there's the risk of air
           oxidation source term, as the Committee has discussed,
           a PTS event, or a spent fuel pool accident.
                       Finally, after I first put out my study in
           spring of '99, DOE revised its EIS calculations,
           accordingly did a better job, but there are still
           flaws in the values that are outstanding in the
           environmental impact statement, and one of those comes
           from the fact that they assumed for some reason that
           in the reactors in the U.S. you have three or you
           divide the core into three equal fractions, and each
           burnup interval is an equal burnup interval, which is
           not the case in a reactor with an 18 month core
           loading like Catawba or McGuire.
                       So they actually underestimate the burnup
           of the second cycle MOX fuel.
                       So what are some of the impacts on severe
           accident consequences from the increased true source
           term using the MAX-2 code, suitably revised after I
           discover an error in it?
                       You find that for early containment
           failure, for a typical early containment failure
           source term, which in this case what I have here
           corresponds to about a one percent overall low
           volatile release; you find that there's a 25 percent
           increase in latent cancer fatalities as a result of
           the initial plume.  That's not looking at the chronic,
           long term consequences, but only what's in MAX-2, in
           what's called the early module, and that's because I
           don't really trust the chronic module in MAX.
                       As far as prompt fatalities go, there's a
           very small or practically no increase, only about four
           percent for early containment failure because the
           particular isotopes that are greater in MOX cores
           don't really influence that much.  Again, the results
           will be available in this paper.
                       Now, I just looked recently at the
           possibility of the high ruthenium release that might
           correspond to a pressurized thermal shock accident,
           and I found that that has a bigger impact on the
           prompt fatalities.  In that case, this is preliminary,
           but there's about a 30 percent increase then in both
           latent cancers and prompt fatalities for a 75 percent
           ruthenium release.
                       DR. KRESS:  What was the nature of the
           error you found in MAX?
                       DR. LYMAN:  It turns out for very high
           releases, you could have more cancer fatalities than
           there were people.
                       DR. KRESS:  Oh, okay.  It was in the dose
                       DR. LYMAN:  Right.  It was not normalized
           properly, and so they fixed that, and it will be in
           the next release.
                       DR. APOSTOLAKIS:  Now, when you're saying
           25 percent, four percent, and so on, you're obviously
           referring to some point value.
                       DR. LYMAN:  Oh, I'm sorry.
                       DR. APOSTOLAKIS:  Is that the mean value
           of something or best estimate?
                       DR. LYMAN:  You mean --
                       DR. APOSTOLAKIS:  What does the 25 percent
           refer to?
                       DR. LYMAN:  Oh, I'm sorry.  Compared to
           the exact same source term applied to an only uranium
           fuel.  So in other words, I --
                       DR. APOSTOLAKIS:  So you did both
                       DR. LYMAN:  Right.  You look at the
           consequence analysis for a particular source term for
           a uranium fuel, and then you keep the release
           fractions all the same, which may not be a correct
           assumption for MOX because there may be greater
           volatile releases for MOX fuel, but if you assume all
           of the source term, the release fraction is the same. 
           Then you just look at the impact of the additional
           actenites (phonetic), for example.
                       DR. APOSTOLAKIS:  Okay.
                       DR. LYMAN:  But I did it over the entire
           spectrum of isotopes.
                       And again, of course, there are different
           release fractions for different accidents.  That's a
           kind of stylized early containment failure, which was
           derived from NUREG 1150.
                       Okay.  So what about the impact on risk? 
           Well, you can look at a set of a kind of complete set
           of accidents leading to a large early release, and
           basing on a NUREG report, which binned a whole lot of
           severe accident scenarios into a small number.  I was
           able to do a rough estimate of what is the impact on
           the average population risk within one mile, which is
           the parameter cited in the quantitative health
                       And so that actually tracks the
           consequences pretty well, about 25 percent increase
           for the DCS core in average risk to the public within
           a mile of the reactor.  That's latent cancer fatality
                       So then I asked if you wanted to risk
           inform, sine it's quite likely that when there's a
           submittal for a license amendment for using MOX fuel,
           then it will meet all of the design basis
           requirements, but the question is:  will it have an
           impact on risk, which could be something you need to
                       And now that the staff has the authority
           to use risk information either in a license submittal
           that's not risk informed, I thought this might be
           something that the staff might want to look at since
           this could be one of the biggest impacts.  The biggest
           impacts of using MOX is not on design basis actions,
           but on beyond design basis.
                       But then this question arises, which the
           Committee has discussed frequently, is the 1.174
           assumes a particular release, and only looks at change
           in LERF, and so the question is:  how do you deal with
           the situation where the actual frequencies may remain
           roughly the same, but the inventory changes?
                       So I did a quick and dirty -- I'm a former
           physicist.  So that's what we do, is try to work with
           what you've got, and quick and dirty way of using
           1.174 was simply to derive what I call an effective
           LERF, which is let's say you have an accident, two
           different accidents and only the consequences change. 
           That's associated with a change in risk.
                       So what's the equivalent change in LERF
           that would lead to the same change in risk?  And so
           it's just a way of using the scale which is provided
           in 1.174.
                       And incidentally, this is also a useful
           way for evaluating what's an extended power up rate,
           and the issue does arise if you have the 17 percent
           extended power up rate.  That's going to lead to a
           significant increase in consequences from severe
           accident, and if that's acceptable, then this increase
           associated with MOX will also be.
                       But inversely, if one isn't, then neither
           will be the other.  So this could be a way of
           addressing at least until the formalism is fixed, to
           address this, a way of addressing things like the risk
           impact of an extended power up rate.
                       DR. APOSTOLAKIS:  So fixing it probably
           will mean not to deal with a LERF anymore.
                       DR. LYMAN:  Possibly.  I mean --
                       DR. KRESS:  If you had delta R you
           wouldn't need a LERF really.
                       DR. LYMAN:  Right, and that's what this is
           just saying.  Delta R is the same for both.
                       DR. APOSTOLAKIS:  Because neither the
           large or the early change, as you said.
                       DR. LYMAN:  Right.
                       DR. APOSTOLAKIS:  Nor the F.
                       DR. LYMAN:  But if this equation isn't
           right, and it may not be because, you know, you end up
           with small fractional increases in risk, and you know,
           the error bars might be big enough that it washes
           those out, but if that's the case, then if this isn't
           correct, then the overall 1.174 --
                       DR. APOSTOLAKIS:  So R is the risk.
                       DR. LYMAN:  Right.  In other words,
           probability times consequences summed over all the
           accidents that contribute to LERF.
                       DR. APOSTOLAKIS:  For whatever risk you
           have in mind.  I mean prompt fatalities.
                       DR. LYMAN:  Right.  In this case I looked
           at latent cancer.
                       DR. APOSTOLAKIS:  So you do have delta R
                       DR. LYMAN:  Right.  You can calculate it
           if you know everything.
                       DR. APOSTOLAKIS:  If you had it or you
           have it.
                       DR. KRESS:  You have to do some sort of a
           PRA.  Now, he --
                       DR. APOSTOLAKIS:  But look.  Lyman says
           that we should use this to define an effective delta
           LERF.  Therefore, you must have delta R.
                       DR. KRESS:  But he used sort of --
                       DR. LYMAN:  Right.
                       DR. KRESS:  -- an abbreviated --
                       DR. APOSTOLAKIS:  And he did that earlier.
                       DR. LYMAN:  And it's like a Level 3 PRA,
           except it's very truncated, and it was based on a
           small set of accidents.
                       There was a study.  I don't have the
           number with me, but they took, let's say, the Sequoyah
           NUREG 1150, and they binned.  You know, you have
           thousands of different initiators.  They binned them
           into a small number of accidents with the same source
                       So it was manageable.  There were three or
           four different source terms and frequencies associated
           with that.  So you could do a kind of very rough Level
           3 and get the risk.
                       DR. APOSTOLAKIS:  Now, instead of doing
           this, it seems to me since you can do a rough Level 3,
           what you could do is take the allowed delta F for
           light water reactors that the NRC staff --
                       DR. LYMAN:  Right.
                       DR. APOSTOLAKIS:  -- has declared is
           acceptable --
                       DR. LYMAN:  Right.
                       DR. APOSTOLAKIS:  -- ten to the minus
           seven --
                       DR. LYMAN:  Right.
                       DR. APOSTOLAKIS:  -- and see what the
           consequences of that are with respect to the
           acceptable change in prompt fatalities and compare
           your delta R with that.
                       DR. LYMAN:  That's actually exactly the
           same thing.
                       DR. APOSTOLAKIS:  It's the same thing?
                       DR. LYMAN:  You're just saying it
           differently, yeah.
                       DR. APOSTOLAKIS:  It's not obvious it's
           the same thing.  Is it obvious it's the same thing? 
           I'm not doubting, but --
                       DR. LYMAN:  Well, I have to think about
           it.  I think it's the same.
                       DR. APOSTOLAKIS:  I can't see it's the
                       DR. LYMAN:  Because you're just saying
           what -- you could rewrite this in that way.
                       DR. APOSTOLAKIS:  In other words, what I'm
           saying is, okay, you can calculate the change in
           prompt fatalities or cancers and so on, but you don't
           know what's acceptable, what delta cancers is
           acceptable, but you have a delta LERF that has been
           declared acceptable for light water reactors.
                       Take that and propagate it to the front,
           the Level 3, and then compare you delta after that.
                       DR. LYMAN:  Yeah.  Do you see where it's
           the same thing?  Because you're just saying if you
           know what the source term is, then you can say, well,
           I know what the change in risk is going to be
           associated with that change in LERF.  Now, if you can
           do the Level 3, then you can propagate that through,
           and then you would get a delta R, which you would
                       This is just doing that backward.
                       DR. APOSTOLAKIS:  And so I guess what
           you're saying is after I take the LERF to the left, I
           have delta LERF  or LERF is delta R over R.
                       DR. LYMAN:  Yes.
                       DR. APOSTOLAKIS:  And there must be some
           other duplicative factor there that counts as R.
                       DR. LYMAN:  Right, if the source term is
           the same.  Right.  It's the same thing.
                       DR. APOSTOLAKIS:  Yeah, yeah.  
                       DR. LYMAN:  You know, it's a very obvious,
           very simplistic --
                       DR. APOSTOLAKIS:  I don't know about
           obvious.  It took me ten minutes to understand.
                       DR. UHRIG:  Are you contemplating a 17
           percent increase in power?
                       DR. LYMAN:  No.
                       DR. UHRIG:  I'm not aware of that.
                       DR. LYMAN:  No.  What I'm saying is that
           since the risk that I found associated with using MOX
           is about, you know, this 25 percent increase.  That
           could be comparable to the increase in risk associated
           with the power up rate.
                       DR. UHRIG:  Well, the power up rate, the
           17 percent typically associated with BWR is not PWR.
                       DR. LYMAN:  No, I'm not saying that it's
           going to happen.  I know Catawba and McGuire are not
           planning to. I'm just saying that's another example
           where you could use this.
                       And, again, if those up rates are
           approved, then, well, at least it's a way of saying
           it.  It's a way of saying -- well, let me go on to the
           next slide because at least this shows you in the
           1.174 context.
                       Okay.  So what's the risk impact of MOX in
           ice condenser plants?  Now, we know the DCH study that
           came out last year concluded that ice condensers are
           substantially more sensitive to early containment
           failure than other PWRs, and this is precisely the
           class of accidents in which you would feel the
           additional risk from MOX because these are the
           accidents where you would have fuel dispersal and
           containment failure.
                       So that in itself is of concern, but here
           I just did -- this is a rough estimate using the
           equation from the previous slide where from the
           McGuire IPE, which is now ten years old, but the total
           LERF, internal plus external, is 4.7 times ten to the
           minus six.
                       So then if you use the delta LERF
           effective equation from the last page, you get a
           number 1.2 times ten to the minus six that actually
           exceeds the reg. guide 1.174 threshold.  At least this
           crude estimate means that it's in the regime where
           changes would not normally be allowed.  So that's the
           first point.
                       CHAIRMAN POWERS:  Actually, I think it's
           in the regime.  It simply means it's in the regime
           where it gets increased management attention.
                       DR. APOSTOLAKIS:  That's pointed out here.
                       DR. LYMAN:  Well, the actual language is
           not normally allowed.  It's the top tier.  Now, it's
           close to the boundary, and nothing is set in stone,
           and you also have permission to use other arguments,
           you know, quantitative arguments to get out of this
           hole, but I would say that at least on the scale
           that's proposed in 1.174, this increase associated
           with MOX is fairly significant, and I wouldn't write
           it off.
                       Now, going back to that, the McGuire IPE
           does not take into account the Sandia finding that the
           early containment failure frequency was under
           estimated by a factor of seven in Duke Power's own IPE
           and PRA, and this, as Richard Lee said, is still a
           matter of controversy.
                       But if you did take into account the
           greater early containment failure frequency associated
           with station blackouts, just again using the IPE
           numbers, you'd end up with a LERF above ten to the
           minus five, which is in the regime where no risk
           increase greater than ten to the minus seventh would
           be allowed.  So that, again, would exclude MOX.
                       Now, I know that the current PRA for
           McGuire is about half what it was in the IPE, but I
           don't know what the station blackout frequency is now,
           and these are not really publicly available, and so I
           can't say anything about that.  But at least based on
           what's public, I'd say, again, that the risk is
                       And, again, the implications for extended
           power upgrades, I'd say, is one way of looking at if
           a 25 or 30 percent increase in risk associated with an
           extended power upgrade, this is a way of evaluating
           where it fits in the risk informed framework.
                       And speeding up, now the MOX impact on
           transience.  This is all pretty well known, but I'd
           just like to point out a few other things.
                       The PTS screening criteria which are now
           under review for all plants may not be appropriate for
           MOX cores, in other words, the ones that are
           appropriate for the LEU may not be appropriate for
           MOX, and one reason is the reduced decay heat
           immediately after a SCRAM in a MOX core would lead to
           a more rapid decline in the temperature in the reactor
           coolant system, and therefore, a more rapid entering
           into a region, a temperature region where the pressure
           vessel might be threatened.
                       Another aspect, well, again, if you have
           an air oxidation source term with greater fuel and
           ruthenium releases, then the source term might be more
           severe for a MOX core in a PTS event, and a final
           point is that because of the greater fast flux, the
           embrittlement is going to be somewhat more rapid, and
           this is not something that Duke Power is planning to
           take into account at its license renewal time limited
           aging assessments.
                       As a matter of fact, Duke made the
           alarming statement that, well, license renewal comes
           first, and then they'll evaluate MOX, and if there was
           a risk that using MOX would impair the ability of
           their plant to operate safely to the end of the
           license renewal period, then they won't do MOX.
                       And when I heard that, I wondered if the
           Department of Energy knew that was their position, but
           considering there's only a two-year, I think,
           difference between when they're doing their license
           renewal and when they'd have to do the MOX assessment,
           it would make sense to do it all at once in my view.
                       Moving right on in the reactivity
           insertion, we all know the increased vulnerability of
           MOX to RIAs or potential increased vulnerability as
           demonstrated in the REP Na-7 Cabri test is a concern.
           And a key consideration is the fuel homogeneity and
           the size distribution of the plutonium agglomerates.
                       And, you know, this has been known, I
           think, for decades, and Westinghouse in its
           consultant's report to DOE recommended -- this is a
           quote -- "adherence to limits on plutonium
           agglomerates in the range of 10 to 15 microns should
           be required."
                       And in that context, it's pretty alarming
           to learn that DCS appears to actually be relaxing the
           existing specification that's in use at the Maalox
           (phonetic) plant in France, when they should be going
           in the other direction.
                       And the Cogema MIMAS plutonium particle
           distribution that's currently achieved has a mean size
           of the distribution of the agglomerates of 20 to 40
           microns, and the specification is no more than two
           percent of the clusters should be greater than 100
           microns in size, and the maximum that occurs is around
           140, I believe, while the DCS specification, at least
           in the version of the fuel qualification plan, which
           we submitted last year, and I understand there's a new
           version now; so this may have changed, but they
           specify a mean size of less than 50 microns and a
           maximum five percent of clusters greater than 100
           microns with a maximum size of 400 microns.
                       So instead of trying to bring this number
           down to the ten or 15 range that Westinghouse
           suggested, they seemed to be going in the other
           direction.  I think if this is actually the case that
           it's something that they need to be called to account
                       Now, on the issue of MOX --
                       CHAIRMAN POWERS:  A 400 micron inclusion,
           a 400 micron plutonium inclusion would be a fairly
           significant inclusion, wouldn't it?
                       DR. LYMAN:  Yeah.  I mean, it's about the
           maximum.  It was the maximum that was set back when
           they did those experiments in the '70s or '60s, and
           hopefully technology has improved since they were
           making this.
                       CHAIRMAN POWERS:  I'm just trying to
           understand what the neutronic effects of a 400 micron
           -- I mean that's a pretty healthy inclusion, isn't it? 
                       DR. KRESS:  It's pretty good.
                       CHAIRMAN POWERS:  I think you would worry
           about that.
                       DR. KRESS:  I think you'd see it.
                       CHAIRMAN POWERS:  Yeah, I think you would
           see something.
                       DR. LYMAN:  Well, it's right in the fuel
           qualification plan if you want to take a look at that
                       Now, generally speaking, we have a lot of
           concerns about the way the fuel qualification is
           coming about.  First of all, the schedule, I think, is
           pretty aggressive.  They hope to load the LTAs and
           start irradiating them in McGuire in October 2003.
                       Then they're going to do it for two 18-
           month cycles, and so discharge would be around October
           2006, and these twice burn LTAs, then they would be
           subject to some nondestructive analysis, but the first
           reload batch would be a year later.
                       So that only gives one year really for
           doing all of the work that both the licensee and NRC
           might want to do on these LTAs.
                       The other aspect is at least according to
           the first version of the fuel qualification plan, they
           wouldn't even be burned up to the maximum discharge
           burnup that they're proposing for the fuel, but would
           fall short, and that's another puzzling aspect.
                       Then the issue of where the LTAs are going
           to be made is still not determined.  As you know, Los
           Alamos has its contract canceled last year, leaving
           the program stranded.  So the two bad alternatives now
           are, one, the LTA is manufactured in a European
           facility, but this raises the issue that they may not
           be representative if it eventually comes out of a U.S.
           plant, especially if the fuel qualification parameters
           are different.
                       CHAIRMAN POWERS:  When you say they're not
           representative, are you speaking of the fact that they
           did not have weapons grade plutonium in them or --
                       DR. LYMAN:  Well, no.  It wouldn't make
           sense if they didn't, but where, you know, there had
           been talk that it might come from England, you know,
           I don't know the details, but it certainly wouldn't be
           U.S. weapons grade plutonium that was aqueously
           purified according to the plan that we have and
           fabricated according to the specifications that DCS is
                       So that has to be looked at.  It may not
           be that significant an issue, but again, given what
           we've heard today about the variability and, you know,
           expectations for fuel, small changes in composition,
           manufacturing parameters, there seems to be some
           sensitivity to these things.
                       And so I would be more confident if the
           LTAs actually were a product of the plant that's going
           to be manufacturing them, but the problem with that,
           which is the other option, is that clearly it's going
           to cause a delay if the U.S. MOX plan is going to be
           the source of the LTAs because who knows?  They'd have
           to establish some sort of a pilot line, I guess, and
           who knows if the fuel coming out of the pilot -- I
           mean, the first fuel -- is going to be suitable or
           representative of a later fuel?
                       So I think there are a lot of issues that
           are not being dealt with adequately here, and because
           of this aggressive timetable, NRC's ability to resolve
           MOX fuel safety issues, I think, is in jeopardy. 
           Again, the time for post irradiation LTA
           characterization testing is inadequate, forcing a
           reliance on proprietary find data, which NRC is not
           going to be able to confirm, and I think the M5
           experience, however it plays out, should give pause in
           this area because whether or not the M5 cladding,
           which incidentally is the cladding that's going to be
           used on MOX fuel, and Framatome is the fuel designer
           and supplier for the MOX program here; whether or not
           it turns out to be adequate and meets the existing
           criteria, I'd have to say that the behavior of
           Framatome since they were aware that they were doing
           ring compression tests; they were aware that there was
           an issue; they were aware of the results.  The Germans
           were making them do these tests.
                       At the same time NRC was reviewing and
           approving the M5 cladding without knowing any of this,
           and the fact is, you know, they didn't ask the
           questions.  So maybe they didn't have to get an
           answer, but I think if Framatome was completely
           forthcoming, they would have notified them.
                       And so I think it raises questions about
           how reliant we should be on foreign data that's not
           confirmed independently.
                       And in this regard, it's especially
           frustrating that DOE appears to be uncooperative with
           NRC's Office of Research, and you may not be aware
           that the Office of Research sent a letter to DOE in
           December requesting that access be granted to NRC to
           have some samples of the irradiated lead test
           assemblies taken to Argonne for NRC's confirmatory
                       DOE's answer was basically, "No, thanks. 
           It's duplicative, and you'd have to work that out with
           the licensee anyway," wouldn't have anything to do
           with it.  It was an evasion.
                       And this is an example of how I think
           things are going to play out especially in the context
           of the budget cuts that we're going to see.  DOE is
           not willing to pay or support any of what it considers
           additional research, and I think that's a mistake.
                       I think that both the timetable and the
           staff resources for MOX safety issue resolution should
           be based on NRC needs and not DOE needs.  You know, in
           an ideal world, NRC should design the research program
           it thinks is necessary to answer the questions, give
           DOE the bill.
                       DR. LYMAN:  And then --
                       PARTICIPANT:  In an ideal world.
                       DR. LYMAN:  Right.  Well, I'm an optimist.
                       Cancellation of the immobilization track
           is going to increase pressure on NRC not to be
           obstructionist in MOX licensing, and I think this path
           for MOX approval is not likely to engender public
           confidence the way things are going.
                       So I would like to see a tightening up of
           the goals and the objectives and a good research
           program addressing some of these concerns.
                       Thank you.
                       CHAIRMAN POWERS:  Any questions of the
                       That was a great presentation.  I think we
           appreciate it when you take the time to come talk to
                       DR. LYMAN:  Oh, I appreciate the
                       CHAIRMAN POWERS:  Thank you.
                       DR. SHACK:  Let me.  What is your argument
           again about why this is appropriate for the power up
           rates?  You're not arguing that the source terms is
           increased in the same way.  Are you just saying that
           you should consider the change in source term and use
           it to modify the LERF?
                       DR. LYMAN:  Well, the source term is
           increased not in the same way, but some of the --
                       DR. SHACK:  Okay, but your argument is you
           should consider that change in the source term and
           modify the acceptance on the LERF.  That's what you
                       DR. LYMAN:  Right.
                       DR. CRONENBERG:  The scale and not the
           source term.
                       DR. LYMAN:  Right.  I mean, this is
           actually discussed here last year where there was some
           argument how do you risk inform this if you don't have
           a tool that takes into account change in source term,
           and I'm saying this is one way to do that.
                       DR. CRONENBERG:  When did the mobilization
           -- was that really canceled?
                       DR. LYMAN:  Well, they suspended the
           contract.  They had had a request for proposals put
           out for a mobilization contractor.  That's going to be
           suspended.  That money was zeroed out for the coming
           fiscal year.
                       They don't say it's been canceled, but
           everyone I know or what I've heard from people inside
           the program is it's dead.  People have been
           reassigned.  The work is over.
                       CHAIRMAN POWERS:  Ralph, we have some time
           scheduled for the full Committee tomorrow on this
           general area of high burnup and MOX fuel.  I'll be
           frank.  I did not see anything that I felt a burning
           need to bring before the full Committee.  Is that true
           or do you have a different perception?
                       DR. MEYER:  No, I think that's okay.  I
           was just wondering what you expected the staff to
           prepare for tomorrow.
                       CHAIRMAN POWERS:  Well, what I was going
           to suggest is, I mean, you've basically given us an
           update on where you stand, that you've gone through
           your PIRTs.  I think that's great.
                       I was just going to suggest that I'd give
           a quick summary to the ACRS and let it go at that.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  I mean, there's nothing
           for us to write a letter about.  So I hope you're not
           expecting a letter from us.
                       DR. MEYER:  Right, right.
                       CHAIRMAN POWERS:  We need to produce a
           letter that says to close out one of the GSIs on this
           high burnup fuel.
                       DR. MEYER:  Yes.
                       CHAIRMAN POWERS:  Okay, and basically what
           we need to be able to say is everything that's listed
           in that GSI is being addressed in the research
           program, and I think we're on safe grounds in saying
                       DR. MEYER:  That's correct.
                       CHAIRMAN POWERS:  Okay.  So it seems to me
           that the only thing we need to do is why don't I just
           give a summary of what went on at this meeting?  You
           guys can go do your work and actually make some
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  And that's not put -- I
           mean, I just don't see a need to have a -- I'm sure
           the Committee members would be very interested in
           what's going on, but that's all it would be, would
           just be technical interest and whatnot, and that's the
           job of the subcommittee.  We get the fun job.
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  They've got to work
                       DR. MEYER:  That sounds fine to me.  So I
           don't have to prepare a presentation tomorrow.
                       CHAIRMAN POWERS:  I don't think you need
           to prepare a thing.
                       Richard, similar I think on the MOX. 
           You're just getting started.  I don't see anything. 
           I think between Med and I we can take your viewgraphs,
           put together a viewgraph that says, "Here's what we
           talked about, and our intention is to come back and
           look again roughly in the fall."
                       Because that looks like when things were
           coming down both from Margaret's perspective and from
           your perspective; is that right, Ralph?
                       DR. MEYER:  Okay.
                       CHAIRMAN POWERS:  I mean that's all I see
           to do.  I think it was a great update, but I just
           don't see anything that the Committee needs to act
           upon, except we need to get that GSI out.
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  But I think that's --
                       DR. MEYER:  That's a separate.
                       CHAIRMAN POWERS:  It's a separate issue
           for us, but I think it's -- I mean, I think what we
           needed from you is the assurance that the research
           program is covering it.
                       DR. MEYER:  The assurance that?
                       CHAIRMAN POWERS:  The research program --
                       DR. MEYER:  Yes.
                       CHAIRMAN POWERS:  -- is taking into
           account everything that --
                       DR. MEYER:  It does.  It does cover
           everything that was said.
                       CHAIRMAN POWERS:  And I think that was all
           that was needed.
                       DR. MEYER:  Yeah.
                       CHAIRMAN POWERS:  Okay.
                       DR. MEYER:  Okay.  Great.
                       CHAIRMAN POWERS:  Any other comments
           people would like to make?
                       (No response.)
                       CHAIRMAN POWERS:  In that case, I will
           adjourn this meeting of the Subcommittee with thanks
           to the speakers.  All very interesting, and at the
           same time somewhat confusing in that there obviously
           is at least one variable that I don't understand in
           clad behavior.
                       (Whereupon, at 3:17 p.m., the Subcommittee
           meeting was adjourned.)


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