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Transcript of ACRS 347th Meeting on 890310 in Bethesda,Md. Pp 182-325.Supporting Documentation Encl
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Issue date:	03/10/1989
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{{#Wiki_filter:, _ - _ _ - _ _ _ _ _ _ _ _ - AcRST'-l7a/ OR G N A' UNITED STATES O NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS In the Matter of: .) ) 1 347th General Meeting ) ) ) ) ) ) ) i i O \\ \\ Pages: 182 through 325 Place: Bethesda, Maryland March 10,ACRS Off.m Cg"y"~ no[ tams ~ ~ ~ L9 89 Date: ice 4 gg_ g _y k g i e a Q u i.U n ____ HERITAGE REPORTING CORPORATION OficialReporters O 1220 L Street, N.W., Suite 600 %Mngwn, D.C. MS 8903210175 agosto PDR ACRS (202) 628-4888 j T-1721 Pnu ( J

182 1. UNITED STATES NUCLEAR REGULATORY COMMISSION 2 [ ADVISORY. COMMITTEE ON REACTOR SAFEGUARDS 3- -) 4 In the Matter ~of: ) ) 5 .) 347th-GENERAL MEETING ) '6 ) 7

Friday, March 10, 1989

-8 Room P-114 m 9 7920 Norfolk Avenue Bethesda, Maryland 10 The above-entitled matter came on'for hearing, 11-pursuant to not' ice, at 9:30 a.m. 12-BEFORE: DR. FORREST J. REMICK 13 Chairman Associate Vice-President'for Research' g^) - 14 Professor of Nuclear Engineering -v-The Pennsylvania State University 15 University Park, Pennsylvania 7 16 ACRS MEMBERS PRESENT: 17 MR. CARLYLE MICHELSON Vice-Chairman 18 Retired Principal Nuclear Engineer Tennessee Valley Authority 19 Knoxville, Tennessee-t and Retired Director, Office for Analysis 20 and Evaluation of Operational Data U.S. Nuclear Regulatory Commission 21 Washington, D.C. 22 DR. WILLIAM KERR Professor of Nuclear Engineering and Director 23 of the Office cf Energy Research University of Michigan 24 Ann Arbor, Michigan 25 10 HERITAGE REPORTING CORPORATION -- (202)628-4888 ___._m_ _._________.-__m_________m_______m.______

P: ~ l' b: wu 183 L. f 1 MR. DAVID A. WARD l Research Manager 1on Special-Assignment L 2. E. I. du Pontide'Nemoursf& Company [ .Aiken, South Carolina Savannah River Laboratory E 3 p 4:

DR. CHESTER P.fSIESS Professor Emeritus of Civil l Engineering 5=

University of Illinois Urbana, Illinois L 6 L MR. CHARLES J. WYLIE 7 Retired Chief Engineer Electrical-Division 8 Duke Power Company ' Charlotte, North Carolina 1 9 DR.. PAUL G. SHEWMON 10 Professor ~, Metallurgical Engineering Department Ohio State University 11' ' Urbana, Illinois 12 DR. HAROLD W. LEWIS Professor of Physics 13 Department of Physics University of California' J/~T -14 Santa Barbara, California E/- w 15, MR. JAMES CARROLL Retired Manager, Nuclear Operations Support - 16 Pacific Gas'& Electric Company SanLFrancisco, California 17 DR. IVAN CATTON 18 Professor of Engineering Department of Mechanical, Aerospace and Nuclear 19 Engineering. School of' Engineering and Applied Science 20 University of California (. Los Angeles, California 21 ACRS COGNIZANT STAFF MEMBER: 22 Raymond F. Fraley 23 NRC STAFF PRESENTERS: 24 R. Bosnak 25-J. Murphy

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[ '185' s ,P R;O C E E D.1,N.G SL 1 2 CHAIRMAN REMICK: Paul,_I guess you'know what'the: g~ agenda-is? 3 11. MR. BOEHNERT: Yes.- Handout No. 5 has--that's the. 5 - handout right here that I passed around. !6 DR. KERR: There'also'is'a draft. letter preparedLby; ~ 7 Mr. Ward which gives some of the key items that are expected 8 to be in discussion. 9 CHAIRMAN REMICK: It is ccming? 10-MR. BOEHNERT: Yes. 11 DR. KERR: .I will tell you the leak before break, 12 that'has been adopted for consideration of restraint primarily 13 in~ containment I think.- It has not'been adopted for defining-()' 14 the way in which pipes behave when'they break for LOCAs, and 15' staff after careful consideration said it should be adopted. 16 for other regulations than pipes,iand are prepared to 17 recommend.that, the SECY to the Commission that it not be 18 considered further, as I understand the SECY. 1 19' There have been subcommittee meetings at which.both 20 the staff and' industry representatives discussed this. We had I 21 a subcommittee meeting on Tuesday of this week, and to me at 22 least, there was no clear consensus on the part of the 23 industry representatives from Westinghouse who presented the i 24 view that from their perspective, defined to some extent by 25 their plants and their experience, that some of the advantages j O HERITAGE REPORTING CORPORATION -- (202)628-4888 l

186 1 of consideration of leak before break could be achieved by 2 making use of the revisions that recently occurred in the way (~)g L. 3 in which LOCAs can be calculated, and that kind of reading 4 between the lines, the hassle involved with that, if they have 5 adopted that approach to achieve the benefit, it might also be-6 achieved by an extension of leak before break. 7 There were presentations from some Owners Group, the 8 owner groups, from some of the individual utilities, and these 9 expressed in some cases a point of view which said that there 10 are things now being done in both procedures and in set point 11 methodology which are artificial, and they are artificial we 12 believe because of the unreality between pipe breaks, and in 13 some cases, they supported this viewpoint that it seemed to me (m y) 34 was not very thorough. In some cases, there was support 15 given--to me, there is not a clear-cut answer to the question, 16 and I think the staff also felt that this was not a high 17 priority item from the noint of view of the safety and from 18 the point of view of what had been achieved, and it was on h 19 that basis that the SECY recommendations were made. 20 I would encourage any comments from the other 21 members of the subcommittee that were present. Mr. Catton? 22 DR. CATTON: If I could comment a little bit on the 23 Brookhaven work that was done, it was rather an interesting 24 study from a lot of points of view. Much of it was a 25 surprise. Aside from showic.g the iradequacy of some of the jgg W HERITAGE REPORTING CORPORATION -- (202)628-4888

.I 187 4 d I l' large-codes,iit showed.that the time of opening'had very t 2; little effect on~ containment pressure or: temperature. 3 DR. SHEWMON: Inadequate in what regard?. 4 ~ DR. CATTON: Kept running.into problems, .They ~ 5 couldn't run the code. It would quit too early;or.they would' '1 6. stop it too soon..It was RELAP 5, Mod 2, Version 36. I don't 7 know where.that sits relative to the frozen version of RELAP. 8 I1just don't know. Whatever it was,.they had difficulties 9 with the code. 1 10 Reducing the break,' reducing the break: size did have- .11 an impact on the containment' pressure and temperature,'but not 12 significantly. They were both' reduced'aLlittle bit. The rate 13i of pressurize and rate of temperature' rise were' delayed..

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14 Actually there.was surprisingly little impact'on anything. L 15 Where-you would expect it, it didn't occur. 16 MR. CARROLL: Also got steam like breaks which are 17 outside of :b.s scope of containment. [ 18 DR. KERR: Any further comments? ] i E 19 DR. SIESS: You wouldn't have expected the time to t: i 20 have any effect on the pressure, would you? l 21 DR. CATTON: If the-heat transfer to the walls of [. 23 your containment were good or something, you might expect 23 delaying it would bring the prescure down. 24 DR. SIESS: Eut delaying it a few 10ths of secondst i 1 25 DR. CATTON: They del.ed it up to 50 seconds and ) l HERITAGE REPORTING CORPORATION -- (202)628-4888

y 188 H 1 they reduced the size of the break.- They reduced the' break ('N 2 down from a two times a hundred percent down to two times ten. \\) 'IESS: I was just talking about the rate, not 3 DR. S ? the size. 5 DR. CATTON: Oh-- 6 DR. SIESS: I am naive enough to think that the time 7 wouldn't make my difference in the pressure reached after 2 8 minutes. 9 DR. CATTON: You dump a.whole lot of steam into a 10 cold room, you are going to condense a lot of it out. 11 Nevertheless, the effect was small. 12 MR. BOEHNERT: The study did not consider-j 13 containment spray at all. ,r 8 L (~ / 14 DR. CATTON: That's true. One of the arguments that 15 was given by industry was that at 50 seconds it was very 16 meaningful because they could get their sprays on and bring 17 the pressure down. 18 MR. BOEHNERT: Blowdown. 19 DR. KERR: There i3 alco some people claimed I f 20 equirnent qualifi cation because of --get passed that time, that 21 the qualification requirement would be different I was I 22 guess a little puzzled 50, 60 seconds made that much 23 difference. That's really. whether that is the only time that l l 24 one considered-- /~ 25 DR. SHEWHON: If you got the, the rupture volume by (_T I / HERITAGE REPORTING CORPORATION -- (202)628-4888

l l'[ 189 1- .an order of magnitude'as the Germans had the feeling:they ( 2 could, was that considered in.this study? .f 3 DR..CATTON: I wrote down somewhere they; cut the 4 break size by'an order of magnitude, yes, and'this didn't make ~ 5 a'whole hell of a. lot of difference in that area. l 6 DR. SHEWMON: Yes. l-7 DR. CATTON: I just-thought I would interpret. I' ~ p l I 8 knew wh'at-he meant. It makes surprisingly little difference, l 9 -and.I don't know'whether that's because there is something a. { ~ I 10 little bit flakey about the code or what. 'It might be. ..I 11 wouldn't have expected a factor of ten cut to do something. 12 DR. SHEWMON: Your source site isn't accurate--a lot 13 longer. () 14 DE. KERR: The stuff eventually gets out and makes a 15 lot of difference. l 16 DR. CATTON: Things like peak clad temperature 17 didn't change very much. Now it did for the factor of ten 18 reduction. That's only because they didn't run it long j l 19 enough, so you don't know. j l 20 DR. SHEWMON: By that time,'if you dropped it by a 'I 21 factor of ten, are we assuming there is no ECCS systen 22 functioning?. .23 DR. C)fTOF: Well, I'm not rure what--ECCS was 24 functioning? 25 MR.'BOEHNERT: Yes. - O.. HERITAGE REPORTING CORPORATION -- (202)628-4888 l

i .190 y l' DR.'SHEWMON:- Drop your rupture size by a factor of i '2 ten,.it ought to do,<the ECCS ought to'be good for.something',. 3 shouldn't'it?' 4' DR. CATTON: I would think'so. 5 DR. SIESS: The blowdown, 6 DR. CATTON: It' extended. blowdown, and I' don't think 7 they, doesn't really get through'the blowdown. They didn't 8 get to the reflood. It was thatLsmall,'so you don't know. 19 DR. KERR: The implication certainly was I think it-10 might have dropped peak clad. 11 DR..CATTON: I would expect.it to. 12 DR. SHEWMON: Peak clad temperature,.whatever that. "13 means. ) 14 DR. KERR: Westinghouse, they could achieve.the same 15 drop by using the analysis. It really wasn't worth-- 16 additional ruleinaking was.not important for that point. 17 DR. CATTON: Particularly because they have gone 18 through the exercise. 19 DR. SHEWMON: Anybody address advanced plants? f 20 DR. CATTON: No. 21 DR. SHEWHON: It's one thing to say you have 22 inherited nonsense and have te live with this, another thin 2 23 to say-- 24 DR. CATTON: Westinghouse did. Westinghouse said / 25 that there were some things they might do to new designs. ] (202)628-4888 H L -__________-____-___ HERITAGE REPORTING CORPORATION --_ _ - _ _ - - _ _ - _ -_ A

191 1 DR. KERR: Leak before break, apparently the staff } 2 is willing to consider this on an individual basis as an 3 exemption they want to make, and that was also brought up as 4 another reason not to go through the rulemaking. 5 DR.-CATTON: I would hope if they, they use this to 6 change the way they do equipment qualification, that you take. 7 a close look at it, because the present way is to use the sort 8 of volume average temperature and pressure and. stick the thing 9 into an autoclave, and that room that you are dumping all this 10 stuff into isn't like that at all. You get wide variations in 11 temperature. If you are going to back off on that, you really ~ 12 ought to go back and take a look at what you are doing, at the 13 qualification. ( '14 DR. SIESS: I guess what is not clear to me about 15 equipment qualification is all of this discussion is in the 16 context of the design basis accident? 17 DR. KERR: Yes. 18 DR. SIESS: And somewhere else we have been talking 19 about equipment qualifications for severe accidents, and I 20 guess the statf has no problem compartmentalizing their 21 thinking in terms of design basis accidents and severe l 22 accidents, but. I do. I think severe accidents one day and 2,1 design basis accidents the other, so that we talk equipment l l 1 I 24 qualification, we should keep in mind that we are not talking 25 severe accidents with this business. We are changing the {} I f HERITAGE REPORTING CORPORATION -- (202)628-4888 E __ _ _ _ _ __ - ___.___ j

192 1 environment from design basis accident, and we don't now ha e. 2 a requirementEfor looking at severe accidents. p). g s_ - 3' DR. KERR: Well-- 4 DR. SIESS: Policy statement. 5 DR. KERR: We have a requirement for looking at 6' severe accidents in the IPE, but there it is not required that 7 the equipment be qualified.. It is merely required'I guess 4 8 thatLit survive a severe accident. Then one can take credit 9 for it, but it isn't required so far as I know. I suppose. 10 there could an outcome of an IPE. 11 DR. SIESS: What you are saying is.we can change the 12 rules here. People can change the equipment they put in'as 13 they replace it and so'forth, and if the PRA doesn't show l() 14~ that, it'makes a difference, they.are home free. 15 DR. CATTON: Sounds like it, but even the 16-instrumentation to follow a severe accident was, is the Reg 17 Guide 197, only requires qualification to the large break 18 LOCA, so it is not going to survive. 19 DR. SIESS: Before we had' severe accidents, i l 20 DR. CATTON: But it was that instrumentation 21 followed the severe accident. l .22 DR. KERR: Maybe we should listen to the staff for a 23 while since they perhaps-- 24 MR. CARROLL: I have one additional issue I would 25 like the staff to respond to, and that's the fairly recent J HERITAGE REPORTING CORPORATION -- (202)628-4888 u ___ 1J

193 1 development on the in situ testing of motor-operated valves, 2 which has gone from a fairly benign program to something that 3 at least in the last subcommittee meeting that we heard, to 4 industry-wide full-scale prototype testing of every l 5 conceivable motor-operated valve is almost the only way out of 6 town to resolve that. 7 Leak before break at least on some systems in the l l 8 plant might mitigate the impact of the Idaho testing that 9 results in the lab. I would like to hear something like that. 10 Do you agree with that, Carl? 11 MR. MICHELSON: Yes. I think I should point out to 12 the Committee there are two important things to keep in mind. 13 We will talk about leak before break and that is such leaks llh 14 before break inside of containment versus those outside of 15 containment, and that there are different kind of 16 considerations to start thinking about when the break is 17 outside of containment. 18 Sometimes people tend to talk about them on 19 qualification and so forth only in the sense that of what is 20 inside the containment, and just keep in mind we are talking 21 about both here. 22 DR. KERR: Did you get--Dave Ward is not here. 23 MR. BOSNAK: I heard just briefly he was not going 24 to be here-25 DR. KERR: His father died this morning. g HERITAGE REPORTING CORPORATION -- (202)628-4888

l 190 1 MR. BOSNAK: I'm sorry to hear that. I think it is gg 2 worth spending a few minutes--my name is Bob Bosak, the U 3 Division of Engineering, Office o' Research. It's worth 4 spending a few minutes just going back in time because I think 5 I heard a few statements here that talked about inside 6 containment, outside containment. 7 The first thing that we had was, of course, the 8 limited scope of amendment to GDC 4, and that goes back to 9 '86, and that again tras limited to the elimination of the 10 dynamic effect, but only on PWR loops. That is the'1 imitation 11 that was implied, so obviously you are only talking about 12 things that are inside containment-l 13 Now what came along following that was the broad n() 14 scope amendment to GDC 4, and that was published as you see in 15 '87, and it allowed elimination of the, again the dynamic 16 effects, and by that we mean internal dynamic effects that go 17 along with the postulated break location, or the dynamic 18 effects that are associated with jet impingemnt and uhipping '\\ 19 pipe. That's basically it. 20 So that allowed the elimination of these dynamic 21 effects in any pipe inside containment, outside containment, } 22 provided that you can show, and the caveats perhapn were l i 23 rather severe, that you were not subject to a series of I 24 deg;adation, and these, we are talking about degradation fg 25 mechanisms such as IGSCC. l (s/ l l 4 HERITAGE REPORTING CORPORATION -- (202)628-4888 l -________-_________D

195 1 I am talking now again about'a. degree because I I Ps-2 think one of the people-that were'here from industry at'the 3 subcommittee meeting mentioned everythingJis subject to 4 degradation. S' What we are' talking about, the' degree, with' respect 6. to fatigue, if you are within established standards, you could a -7 certainly apply it, but if you'were not,.then you could not, 8 and we were also. talking about large. dynamic loads such as 9 water hammers, steam hammers that'might occur in certain 10 systems, so if you were in a. system'where'those were prevalent 11 an'd'you couldn't really show that, that you had taken whatever-12 precautions you'needed to in' design'and operation.to reduce 13 the prevalence of those things, then you would not be able to (])' 14 use leak'before break, so that's where.we were here with 15 ' respect to the second bullet. 16 Now we had coming from the Commission when they ~ 17-approved going ahead and publishing the broad scope amendment-18 a staff requirements memorandum that.came out'which said 19 because in the comments tuat we.had here.on the proposed 20 revision 4 we had several comments that said why not apply'this. 21 to environmental qualification of equipment? Why not go 22 further? They even mentioned the containment, but in the SRM, 23 the staff requirements memo, which came out,.they asked the 24 staff to review whether ECCS particularly and the 25 environmental qualification, whether they could be modified HERITAGE REPORTING CORPORATION -- (202)628-4888

196 1 using leak before break. 2 I think they were impressed by the fact that G( 3 eliminating the dynamic effects of pipe breaks really did 4 achieve a safety benefit, and they wondered whether or not 5 this could be extended to these other areas to also achieve 6 some, the word was safety benefit, but I don't think the staff 7 felt it was limited to safety benefits if we had something i 8 that was in effect safety neutral,'but from the, from the 9 point of view of the operation of the plant, it simplified the 10 operation, or achieved millions of dollars in savings for a 11 utility, we certainly would not rule that out because it was 12 safety neutral, so that's where we were here when we requested 13 comments from the public in this area. () 14 (Slide) 15 MR. BOSNAK: So that notice that went out soliciting 16 public comments was published last April.'88, and we in effect 17 pleaded with those that were going to respond to come back 18 with something that was factual. In other words, we have 19 heard a lot of hand waving, what we characterize as hand q 20 waving arguments. What we want is some factual arguments that 21 really the staff could use to decide whether or not to go ] 22 forward with further rule change or even further rescerch, so l 23 that's, that was this that went out in April. ] i 24 Now the policy statement that we developed as a 25 result of the comments that we, we had received went to the HERITAGE REPORTING CORPORATION -- (202)628-4888

197 1 Commission last November, and we got some 21 comments. Some 2 'were positive. Some were negative. Some were neutral again 4 3 as you might expect. 4 (Slide) 5 MR. BOSNAK: Twelve of those opposed the expansion 6 of leak before break. I'm not going to really dwell on those 7 because the staff believes that it has the objectione, covered 8 in the policy that it has developed to use leak before break; 9 in other words, which systems would it be applicable to. 10 Several of the comment letters mentioned the Surry pipe break 11 and several other things that we believe we have covered, so 12 what I would like to do is to go on to the positive letters. 13 (Slide) llh 14 MR. BOSNAK: And explain what we were able to 15 perceive as the potential benefits from the positive letters. 16 I want to focus on those. 17 Does anybody have a question here on the--before we 18 leave the negative letters? a. ',t 19 DR. SHEWMON: Do we have all a copy of the proposed .-r '/ 20 policy statement? 21 MR. BOEHNERT: Yes, sir, it is in the notebook. p. 22 DR. S3EWMON: Okay. So you can tell me what page? 23 MR. BOEHNERT: Yes. In item 9, it is page 15. , i 24 DR. SHEWMON: Thank you, ro ahead. 25 (Slide) g HERITAGE REPORTING CORPORATION -- (202)628-4888

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) 1 MR. BOSNAK: Let-me start first with the ] (' 2 environmental qualification. The letters, I would' -i l 3 characterize them as'being ratherLqualitative in nature, j l '4 Obviously if you can reduce the profile.that you would have to 5 qualify a piece of equipment for, if it is less harsh, you,are 6' going to have perhaps more suppliers available. If you can 7 use a standard profile, that would have some advantages. 8 The standardization also is more positive.than to 9 have each and every plant have a, be a different profile. If 10 that were possible, that would be a, a' great advantage, but 11 one of the things that we were concerned about and nobody 12 tried to offer any. positive suggestions other than it would 13 have to be done, what would be the replacement criteria?. j 14 What, what would we use? Would we have to worry about a 15 bolted connection failing? Would it be a valve bonnet? What 16-would we use? And obviously certainly it is not impossible to 17 come up with some alternative criteria, but it takes a good 18 bit of work to do that, and we had hoped that perhaps the 19 industry would utilize a study contract with EPRI or others to l .20 go through and perhaps pick an individual plarit, and show us 21 just what the alternative criteria might be, but ao at lart 22 up to the present, that has not been done or has not been l 23 suggested, and we would certainly be receptive to that, j. 24 In fact, the broad scope rule provided for 25. exemptions in this particular area with the hopes that perhaps 1 I HERITAGE REPORTING CORPORATION -- (202)628-4888

199 1 one or more plants would take this opportunity and to try to 2 achieve those, and those are potential benefits. They don't 3 want to disagree that, that there might be potential benefits 4 available, but right now, they are somewhat elusive because l 5 this additional work needs to be done and it has not been 6 done. 7 We think the industry is in a better position to do 8 that certainly than the, than the Commission staff, so as we 9 said here, the bottom bullet, inside containment, you would 10 have to, if you are going through such a study, you would have 11 to determine whether or not all the lines were qualified for 12 leak before break. 13 Currently not all of the lines would qualify, so k 14 that the environment is not expected to change very much, and 15 you heard the report of the Brookhaven study that was done for 16 the Committee which again indicates that inside containment 17 perhaps we are not going to have much of a change, but a study 18 using alternative, alternative criteria, in other words, we 19 don't, no longer have the pipe break, and of course with 20 respect to the severe accidents situation, there isn't any 21 alternative criteria that severe accident studies I think are, 22 all depends on the large break LOCA to establish the necessary 23 environment, so if we go to something else, what will satisfy 24 both areas? 25 And one of the things that I, I hope we don't g _"""? " " """ "' " c "" "^ * " -- <202)e28-4888

l. b [ 200 i f-10 1 repeat, not a mistake ~, but in the past, we have tended to r~' L 2 design for:some of-this-severe conditions.and including;the (L \\ - '3 pipe restraint and jet impingement' shields and have not 4 overlooked, but perhaps not come up with a balanced' design 5 'that, that. worries about normal operation as well as the less 6 ~ probable' event, so we need to have a balanced design no matter l 7-where we go with respect to' severe accidents, and in i 8 particular, we come up with alternative' criteria. 9 (Slide). l l I 10 MR. BOSNAK: So I think I have already. pretty well i 11 covered this, that we would like, we would.have preferred to 12 have seen some tangible evidence that there is, there has been-l 13 a study performed by the industry. () 14 Up until now, there hasn't,.but there are some other 15 than potential benefits, really achievable benefits, so we 16 believe that, that the exe,[topms that are now available under-17 the broad scope rule would serve that purpose, and if we, and 18 if we did nave several, we would certainly be willing and.able 19 to carry that on and pursue a change to 50.49, the 20 environmental qualification regulation, if that were 21 indicated. 22 Now anfety benefits, and I will move on to the ECCS 23 area. 1 24 One of the things that we have to be concerned about I 25 is the cold quick starts of emergency diesel generators, and {) HERITAGE REPORTING CORPORATION -- (202)628-4888 ]

201 1 that has been alleviated by the new rule, the new Appendix K 2 rule, and also the staff issued a generic letter sometime ago f-) (_/ 3 that reduced the frequency of testing these emergency diesel 4 generators, and they do have to start--the period is 5 somewhat--within ten seconds, so it's a severe requirement, 6 but again, the leak before break rule would not offer anything 7 that's not already available. I think that's, that's the 8 important part. 9 DR. KERR: Is the application that leak before break 10 would still have to start within ten seconds? 11 MR. BOSNAK: If you use the leak before break, the 12 necessity for starting within ten seconds is, is no longer. 13-required. In other words, and with the, with the modified () 14 Appendix K rule, again you don't have to have these fast 15 starts. 16 DR. KERR: Okay. 17 MR. BOSNAK: With the smaller, more realistic break. 18 DR. SHEWMON: What does the ECCS rule involve for 19 longer times? 20 MR. BOSNAK: It is called ~-I'm not familiar with it, 21 but it in called best estimate methodology. 22 DR. S36WMON! I am more familiar with that. My 23 question had to do with what kinds of time periods we are 24 talking about for the starting of the diesel. Does it go to gs 25 minutes or-- d HERITAGE REPORTING CORPORATION -- (202)628-4888 u

r_____ 202 1 MR. BOSNAK: I think it can go, but I don't want to /T 2 say that it, it is in the order of a minute, but I believe .,J 3 it's somewhat increased. 4 My question came, or there was a discussion at the 5 subcommittee about gas turbines, and gas turbines need I 6 somewhat of the order of ten minutes or more, and the, i was 7 said that the new Appendix K rule was not capable of providing 8 relief in that situation, but there is no one that's currently 9 using I guess turbine for this particular service. They are 10 using it for Station Blackout, but that's a different i 11 situation, so you, so I think the answer to your question, it s 12 is somewhat less than the, than the ten minutes, somewhat in 13 the order of probably one or two minutes. /~~ (,) 14 MR. BOEHNERT: That's the same figure I have heard, i 15 like one minute, one or two minutes. 16 DR. SHEWMON: We have upped it by a factor of ten? 17 MR. MICHELSON: Six. 18 MR, bOSNAK: The other advantage here, and this was 19 contained in one of the letters from the, I think Westinghouse 20 mentioned it, an1. also Advanced Fuels, and this perhaps^of all i 21 of the things that I have seen, is the one that I believe is 22 of course the most important, the fact that you would be able 23 to reduce the radial fluence and thereby extend the vessel 24 life; in other words, reduce the rate of embrittlement. l (~'/) 25 This is quite important, but again both letters, \\_ HERITAGE REPORTING CORPORATION -- (202)628-4888

203 l 1 Westinghouse and the Advanced Fuels letter, indicated that 2 they could achieve this, this particular advantage, with the g3 (J ) 3 new Appendix K rule. Now if that doesn't work out because f 4 that rule is only several months old--again, I would say that i 5 the, the staff would be receptive to receiving requests to 6 utilize leak before break if this really doesn't give us that 7 particular advantage, but currently both, both companies state 8 that those are available, so-- 9 MR. CARROLL: Get me calibrated. If I came in a few 10 months from now and said hey, I would like to take advantage l 11 of leak before break for this reason, did you indicate that 12 there was an exception in the, in the existing-- 13 MR. BOSNAK: Well, that particular exemption was () 14 written into the broad scope rule for EQ, 15 MR. CARROLL: Just for EQ? 16 MR. BOSNAK: Just for EQ; now whether--the staff, of 17 course, is always ready to listen to someone coming in and 18 requesting an exemption from an existing regulation for some 19 good technical reason. 20 Now if your question was directed to the F.CCS area, 21 that is not specifically, was not specifically writter, into 22 the rule, but again, the exemptions, exemptions in general are 23 provided for. 24 MR. CARROLL: It is a harder way to go, though, if 25 it isn't in some rule. O HERITAGE REPORTING CORPORATION -- (202)628-4888

204 1 MR. BOSNAK: One of the letters that we had that--in e' 2 fact, let me get to it. It may help to answer your question, l .f )s 3 MR. MICHELSON: Before you go down to that, what 4 puzzles me, of course, is once you ask for an exemption of 5 under the leak before break, then you have to also identify 6 for your design basis what your;new break size is. 7 MR. BOSNAK: Absolutely. 8 MR. MICHELSON: Then you get into these questions of 9 whether it is credible to experience a loss of a manhole 10 cover, loss of a valve bonnet and so forth, so as a part of 11 that same submittal that justifies getting the peaking factor 12 down under leak before break, I assume they also justify what 13 break they are now going to operate under. Is that correct? (O,) 14 MR. BOSNAK: They would have to do that. 15 MR. MICHELSON: Then you would review that new 16 proposed break along with the rest of it? 17 MR. BOSNAK: I am not trying to imply that it is 18 going to be easy, but there is --- 19 MR. MICHELSON: You will have to do some internal 20 thinking at that time as to what had gone on in the past and 21 may have to be resurrected again as to what 5ind of breaks are t 22 we even talking about since the Agency really hasn't addressed 23 breaks in components other than pipes because pipes always 24 seem to bound most of the things we thought about. 25 MR. BOSNAK: That is correct. We have always used [} 4 HERITAGE REPORTING CORPORATION -- (202)628-4888 i _A

205 1 the pipe break as a bounding situation, haven't worried about 2 manway covers or bolted connection. 3 MR. MICHELSON: It's easier to understand than these 4 others, but it is more subject to rigorous analysis perhaps, 5 but now you will have to go back and make some rigorous 6 analysis to convince people that you have the correct break 7 size. 8 DR. SHEWMON: It's easier for some to understand. 9 Actually you always will have something like a six or eight 10 inch pipe break as one bounding thing because you can't apply 11 leak before break below some smaller limit that comes out 12 someplace in that range as I recall. 13 MR. BOSNAK: Because of the leakage detection. llh 14 MR. MICHELSON: They may have to sharpen up their l 15 leakage detection to get the size on down. 16 DR. SHEWMON: Well, it may rain money tomorrow, too, 17 but for now let's talk about where we are, and on that, you 18 have got something like a 6 inch pipe break that would be 19 bounding. Whether bonnets are worse than this or not we have 20 to look at. 21 MR. MICHELSON: Manhole covers are clearly worse in 22 most cases. 23 DR. KERR: Is there any reason to think a manhole 24 cover wouldn't leak before it broke? 25 MR. MICHELSON: That's the kind of analysis you have HERITAGE REPORTING CORPORATION -- (202)628-4888

206 1 got to go through now to justify that it would indeed leak 1 1 (~; 2 before it broke, and I haven't seen that analysis. I don't j 'L) l 3 know if it has ever been done. I l 4 MR. BOSNAK: I just want to point out with this 5 slide that the new sCCS rule can be applied across the board. 6 In other words, we are not worrying about degradation here. 7 That you can apply it across the board, whereas our current 8 rule, you have to come in and show the degree of degradation 9 is not going to get you into trouble. 10 (Slide) i 11 MR. BOSNAK: Now I think this is a--I do want to 12 cover your question about, about MOVs also, but one of the 13 letters that--and it was addressed to the Committee. It just ry (_) 14 arrived just a few days before the subcommittee meeting, 15 mentioned the fact that it says, I am just going to quote--in 16 part, we note that the absence of such criteria, and it is the 17 criteria that Carl Michelson is talking about, clearly hampers 18 licensees in utilizing the exemption process. 19 Well, that's certainly a correct statement, but it 20 says that effort, including perhaps additional research, can 1 21 only be feasibly undertaken as part of a rulemaking. 22 Well, I disagree with that. Certainly any effort by L 23 industry, we don't have to have a rulemaking effort underway 24 for anyone to come in with a technical justification for doing 1 /~} 25 something differently, and one other thing that I did want to V E (2023628-4888 nsaI m s ase ar m ne aA m N --

207 1 mention, perhaps somehow or other you may wish to' cover this ) 2 in the letter that you are going to address to the Commission, 3 but it says in fact the group is concerned with the generic 4 implications of the staff's apparent position in the request 5 for comments that rule may not be undertaken unless j l 6 substantial safety benefits will be derived. INdeed, as a l \\ l 7 general proposition, the declining to pursue new technologies 8 that while allowing maintenance of at least the same level of 9 safety may produce significant cost savings for licensees, 10 could wholly eliminate incentives to explore and apply such 11 new technologies. 12 Certainly that's, that is a wrong impression. We 13 don't need rulemaking activity for anyone, even including ggg 14 ourselves, to perform the necessary research to develop the 15 technology and justification for coming in and doing 16 something, and we tried to explain that, and the only reason I 17 can give for perhaps that misunderstanding, that came from a 18 legal firm, so perhaps they feel that a rulemaking is 19 necessary, but the staff certainly does not feel that that was 20 necessary, and in fact, when we were developing the 21 justification to make the change to GDC 4, the initiel change, 22 a rulemaking activity was not in place. It came in after we 23 had the, you might say the technical justification in hand to, 24 to pursue the rule. 25 DR. SHEWMON: One question--you seem to have HERITAGE REPORTING CORPORATION -- (202)628-4888

208 _] (: 1: finished your presentation.

\\ i 2

MR. BOSNAK:- 'Yes, sir. I do want to get back'to-- lh 'J - 1 3 DR. SHEWMON: The original GDC 4 letters, their 4' rules or whatever, essentially BWRs were exempted'because of 5 the susceptibility of piping. They had to have IGSCC. Over-6 Ethe last year, since that was started, the, there has been a 7 lot of changing now to types, and when they have changed these 8 out,'I presume and would be amazed if they hadn't gone-to 9 non-susceptible piping as defined. 10 'MR. BOSNAK: 316 nuclear grade. 11 ~DR.:SHEWMON: 0313 Rev. 2.or.whatever; have you had-12 anybody come back in and say now we want to remove' pipe width. j 13 restraints because of this or-- () 14 MR. BOSNAK: I checked on that this morningLjust'to-l 15 see if we have had any requests, and they, they say that there 16 have not been any, but they expect to have some, and the-broad' 17 scope rule would again permit that for the pipingfthat is no 18 longer in a position that's, you know, that's prone to IGSCC. 19 In other words, if it has been replaced or you are using some 20 of the mitigative schemes, IHSI or mechanical-- 21 DR. SHEWMON: The recirc piping is not considered 22 part of primary system?- 23 MR. BOSNAK: It is the-- 24 DR. SHEUMON: Why do you need the broadened scope 25 rule? Is it a limited scope? { HERITAGE REPORTING CORPORATION -- (202)628-4888 s

209 1 MR. BOSNAK: Limited scope was only for PWR main 2 loops. O 3 DR. SHEWMON: It was explicitly stated that way. 4 MR. BOSNAK: That's right, so a limited scope rule 5 would have not applied to a boiling water reactor. 6 DR. SHEWMON: I see. I had thought that was only 7 because it was IGSCC. 8 MR. MICHELSON: One small thing that bothers me 9 about the fact that people can replace the pipe with nuclear 10 grade materials and then declare, declare leak before break, I l 11 think the thing that bothers me about this is that we are 12 running into these odd situations wherein when they matched up 13 to the nozzle, for instance, a little bit of the butter of the 14 other material is still on the nozzle and the butter is now ggg 15 cracking. I think you are familiar with that situation. 16 MR. BOSNAK: They can't just declare leak before 17 break. They come in and they have to go.through the-- 18 MR. MICHELSON: How do you look at those interface 19 situations as still being potential break locations, 20 recognizing that there is going to be some of the previous 21 material in the buttered area? 22 MR. BOSNAF: Well, again, we haven't had a situation 23 such as that, and-- 24 MR. MICHELSON: I think some cracks are showing up 25 somewhere presently in which that is the situation. HERITAGE REPORTING CORPORATION -- (202)628-4888 i eiis ima

/ y '210 1 MR'.1BOSNAK:.:All I'can say right now,-how that would .2 be[ handled) it would have to be: reviewed. L .3 MR. MICHELSON: Okay, but right'now you would have 4 passed that as a leak before break pipe. 5 MR. BOSNAK: Wouldn't have~ passed it. -They would 6 still have to go through the, through the fracture mechanics- '7 evaluation. ~ 8 MR. MICHELSON: Are you, were you requiring-all the 9 buttered, all the foreign material in the buttered areas to be 10 removed before the new pipe was installed, or they just didn't 11-do it or--- 12 MR. BOSNAK: You are talking about nowfreplaceme'nt 13 on BWRs? () 14 MR. MICHELSON: That's right. 15 MR. BOSNAK: Whether that occurred or not, I really 16 don't have the information. 17 DR. KERR: We had a break scheduled about ten 18. - o' clock. Is this a convenient time for a 15 minute break? y .19 MR. BOSNAK I'm finished now. I just was getting 20 into questions, and we had one on HOVs that I wanted to-- 21 DR. KERR: Please go anead with.that. 22 MR. BOSNAK: Obviously the fact that the load i 23 situation under which the valve would have to close, that;if 24 you demonstrated leak before break, would be much' relieved, "25 and the fact that we have found that a lot of valve venders [ HERITAGE REPORTING CORPORATION -- (202)628-4888

211 l l 1 have never really, were never really advised that the 2 actuator, the package near the, that they are designing would 3 have to close under these kinds of loads, it was a major 4 factor, so if that is applied to that specific line, it is 1 5 going to have a positive benefit. l 6 Was that your question? 7 MR. CARROLL: Right. Well, and I think this ) 8 situation on in situ testing of MOVs has been an evolving one 9 and I guess Bob Baer and his merry band have most recently 1 1 10 come to, pretty much have come to the conclusion that, that a l 11 good deal of prototype test, something probably is going to be 12 needed as opposed to what they were originally proposing, 13 which is a very expensive proposition. lll 14 MR. BOSNAK: Well, again-- 15 MR. CARROLL: Their answer when I raised this in the 16 subcommittee meeting a couple of weeks ago was well, not many 17 MOVs would really be in systems where leak before break would 18 apply, but in thinking about it a little bit more, I'm not 19 sure that I agree. 20 MR. BOSNAK: Feedwater lines, they may not. 21 MR. CARROLL: But the Idaho testing, of course, was 22 done explicitly to look at a BWR reactor cleanup line 23 isolation, which was good. 24 MR. MICHELSON: Well, yes, that's--it's not clear 25 whether reactor water cleanup would be able to easily be HERITAGE REPORTING CORPORATION -- (202)628-4888 --ii:iii im

[, 4. '212 ' 1) qualifiedrin the first place. Many plants,.it is not ev5hi. ~ '2 ' seismic. O 13 Second place, it's many cases,'.part stainless' steel, l 4 stainless steel-- 5 MR. CARROLL: I'm almost positive,LCarl, that;the-6 system is entirely stainless steel. 7 MR. BOSNAK: I think it is stainless steel.. 8 ' tut. MICHELSON: Yes. I'didn't say.how much.of it., 9-I didn't want to get into an argument. It's a problem on the 10 stainless, 11 '}Ut. BOSNAK: It is prone to IGSCC'or what kind of 12 mitigative things'they have done,'all that would enter into 13 it. ( }- 14 MR. MICHELSON: It is not nuclear grade, not'QAed'in-15 'many cases, and so forth. 16 MR. CARROLL: The only point'I'am making is.that I 17 would hate to close the door on leak before break"as.being a- -] 18-possible way to mitigate-- a 19 MR. BOSNAK: That ptrt of it is not closed. What we- '20 are talking about is the extension to EQ and ECCS. That was , 21 the part that we are saying we don't want to go intofany more 22 rulemaking now into either Parts 50.46 or 50.49, but the-23

availability for the dynanic effects which is what you are

?4 talking about, that's there. It is available. All you have 25 got.to do is to show that if you, if you have a line that's HERITAGE REPORTING, CORPORATION -- (202)628-4888 ___-___---_.____--__-_-_.__-____-A

p + L,

213 r

- l-

troubled by'these degradation mechanisms, to show that'the s

.2 degree ~is'not, is not severe. 3-DR..KERR: Further questions? i: l' 4 CHAIRMAN'REMICK: All1right. Let's take,'let's'take ESL a' break until 10:30. -6 (A'brief recess was taken.). 7 CHAIRMAN REMICK: Gentlemen, could we' reconvene? p 8 Dr. Kerr,.do you want to continue? !5 DR. KERR: Mr. Siegel representing Combustion 10 ' Engineering Owners Group'is slated for.hppearance at this. 11 time. '12 ' MR.'SIEGEL: Thank-you for the help. My name is'Ed' . 13 Siegel. Ifam from Combustion Engineering, and we-are here nr-\\. - 14 again this morning to talk about our views on extending the \\_/ 15 applicability of leak before break, and we have modified our . 16 presentation just a little bit from what was presented on 17 Tuesday. I think I have too many. notes to put'on one little 18 table here. ~ 19 (Slide) 20 MR. SIEGEL: What I would like to start off with ife 21 I could is just a few quick slides to show where we are at 22 Combustion Engineering with leak before break. { 23 We have been working in the area for over 19 years. 24 Started with nain loop leak before break as the rest of the 25 industry. Palo Verde was the first plant that we analyzed and {} 1 HERITAGE REPORTING CORPORATION -- (202)628-4888

214 I 1 had approved for' leak before break for the main' loop piping; 2 1987, all other CE Owners Group plants were included in an ,s \\_] 3 evaluation for leak before break of the main loop piping, and 4 a topical record of that has been submitted to the staff and 1 5 is being reviewed. 6 The results of that analysis were not surprising to. j 1 7 us. All the plants qualified for leak before break, and that 8 tended to increase our confidence in the analysis techniques 9 and the reliability of the results. 10 CHAIRMAN REMICK: Could you tell us what were.the 11 main benefits of doing that, qualifying--what did it. enable 12 you to do that you couldn't do before? 13 MR. SIEGEL: The benefits that people, that the-() 14 utilitics are interested in for going ahead with the main loop 15 pipino were fairly wide ranging. They had to do with the pipe 16 work restraints that were mentioned earlier. In some cases, 17 loading on fuel assemblies were reduced because of the removal 18 of the design basis load for double-ended guillotine breaks. 19 Pump cable supports in some cases were a problem that 20 utilities were having during their ISI inspections. This 21 allowed them to remove that. 22 MR. CARROLL: What kind of supports? 23 MR. SIEGEL: Cable supports on reactor coolant pumps 24 at one of the participant plants which were there only for the 25 purpose of the double-ended guillotine break loading, and some 3 "" "^ * " -- (202)628-4888

)

s ) 215 ) 1 studies:on.large c'omponent snubbers had been affected. 14r i 2' have been able to either reduce' snubber testing requirements,- /N - N) 1F -in'other'words, broaden'the' acceptance bank for snubber test. l 1

4'
for.the'large numbers,1and in some cases'we have been.able to; j

l 5 -justify. lowering load requirements in'those snubbers-and- ] i. 6 working toward even removing some snubbers, and this isLon the 7 major components we are talking'now. 8 CHAIRMAN REMICK: Thank'you. 9 (Slide) 10 MR. SIEGEL: One of things that I think is ~I 11 important, our-view on what we are discussing today is through. H 12 all this work in leak before break, and over the years we have 13 looked at each one of these issues as part of the work on-1 I) '14-fraction mechanics, material studies. We have developed a-15-great deal ~of confidence in the technique itself, and I guess 16 the, the conclusion is we believe in it. We think it'means. 17 something. If you follow the present guidelines for leak 18 before break analysis, you do it properly, we think the result-19 is a meaningful result. '20 DR. KERR: Is that because you have gone through it 21 so many times? 22 MR. SIEGEL: It is not so much-- 23 DR. KERR: Additional experimental evidence? l 24 MR. SIEGEL: I'm sorry? 25 DR. KERR: Or that you have some additional HERITAGE REPORTING CORPORATION -- (202)628-4888 j

L. 2161 1 experimental evidence? .2 -MR. SIEGEL: A' great deal'of.the confidence comes { '3 from-a large' number.of analyse using material. testing data for 4 crack behavior, stability of large. cracks in pipes, that is'a 5 combination of material testing and.rather detailed. analysis. L L 6 Evaluation of dynamic effects also includes dynamic-I 7-testing of material properties and how a crack behaves under a- ) l l 8 dynamic load rather than a quasi-static load. l I 9 .The material property evaluation, the JMJDC has been, 10 factored.in and-we have found, for example, in our main loop' 11 piping-work that we just completed for'the remainder of the 12 CEO plants that'using either of these two we still meet the 13 criteria for leak before break, and we have in fact concluded-I) 14 more conservative value is the proper one we believe in our 15 . analysis, and that's a fairly recent conclusion. I think.that-16 just shows further progress in why we still have confidence 17 that the results are meaningful. 18 DR. KERR: Thank you. 19 MR. SIEGEL: We have compared our very detailed 20 analyses with some of the EPRI simplified methods and found 21 good correlations. We have also started working on smaller 22 flexible lines, surge lines, and in particular, and found a 23 good consistency between analytical results and material 24 property correlations. 25 (Slide) HERITAGE REPORTING CORPORATION -- (202)628-4888 a

. y. I' 1 MR.'SIEGEL: We are' presently doing addit'ional' work o 2 in~this area. AYGN are the initials for the two Korean plants . that Combustion Engineering is presently designing. Weihave= 4 eliminated guillotine breaks in the main loop piping. 5-We have also shown that in the surge llineLdesign,- 6 even with the occurrence of stratified flow that is presently 7 being evaluated in this country, we were able to both design a 8 surge line that was more accommodating to try to fight flow 9 loadings, at the same time satisfy leak before break criteria. i 10 We presently have initiated an effort within the 11 Owners Group with three participants at this time to consider: 12 'the main steam line inside containment.- Yes? 13 DR. SHEWMON: On your first bullet there when you ( 14 say that you have eliminated these breaks, consideration of 35 them, this has been with regard to dynamic effect's only? 16 MR. SIEGEL: That is correct. 17 DR. SHEWMON: Okay. 18 MR. SIEGEL: In the issue of the main steam line, 19. which is probably the next major area that we are looking at 20 now, we have started this work for the portion of the main 21 steam line that is within the containment. Our focus 22 primarily has been within the containment. We see that's 23 where most of the major benefits are to be gained. 24 We have at the staff's request submitted a report to 25 the staff of why we consider that portion of the main steam } HERITAGE REPORTING CORPORATION -- (202)628-4888

3 1 I 218 1 line an appropriate candidate for leak before break, and my f"S 2 understanding is we'have received at least some informal ] b/ L 3 concurrence pending further detailed analysis on our part. 4 MR. CARROLL: That's a carbon steel line? 5 MR. SIEGEL: Yes. Combustion Engineering main loop 6 piping was also carbon steel. 7 MR. CARROLL: Clad carbon? 8 MR. SIEGEL: Yes. This effort is, it was started, 9 it is presently on hold over some issue with review of feeds { l i 10 for topical reports, and while the Owners Group is discussing { l 11 those types of issues,.the technical work has come to a 12 temporary halt. 13 (Slide) () 14 MR. SIEGEL: As was stated earlier, we are in 15 accordance with the present guidelines. These are the areas j .t 16 where once a leak before break analysis is performed, and the i 17 results are successful, these are the areas that are affected i 18 by it, and the reason I presented these initial slides is to J l 19 emphasize the fact that all the work we have done, we believe 20 it is very meaningful type of technology. We believe it is 21 something people can have some faith in. Therefore, we feel 22 comfortable with the next portion of the presentation, which 23 is our recommendation on extending the applicability of leak 24 before break results. ) . (~) N 25 (Slide) HERITAGE REPORTING CORPORATION -- (202)628-4888 j

-219' 1 MR. SIEGEL: 'Before what we haveLfound in discussing-- 2 future applications is'that the benefits that a plant'would. 3-see, one, may be extremely substantial, and they fall into-4 generally these three categories--the environmental l ~5 qualification of equipment, containment pressure / temperature-6 profiles, ECCS system requirements, and in each case, we see. 7 benefits that I think fall into the three categories of' safety l 8 enhancements, man-rem exposure reductions, and significant 9 cost savings, and we are going to expand on each one of these 10 in the coming slides. 11 Probably the two biggest areas that are important 12 for the next slidesLI am going to present relate to the harsh 13 environment that is predicted in containment today relates to () 14 it in two ways. 15 One is the rate of occurrence. Right now in a large 16 break LOCA, people assume a ten-second ramp time for the 17 development of the harsh environment. It turns out in some of 18 the work we have done, the ramp rate itself is a very 19 significant variable in terms of effect on the plant, and I 20 will describe that when I take about EQ of equipment. 21 The second important factor is what peak pressures 22 and temperatures do you actually reach if you start to take i 23 credit for leak before break in other pipes? And while we 24 have not done the detailed work of determining the next 25 controlling break size, we have looked at generic plant. i HERITAGE REPORTING CORPORATION -- (202)628-4888 ) a

x 220 1 We anticipate that'the next' largest break' size'after ~ 2 we do this work'at least on the primary side'would be'in the'8 3. to 6' inch, 6 to 8 inch range, and that'from that,:our' judgment ~4 is that reductions in the peak pressure in containment.may be-5 as high as 30 to'50 percent. 6 I want to emphasize that we do not have detailed 7 analysis to back that up right'now. Some of these are based 8 on IPEs that were done eight to ten years ago at Combustion 9 Engineering. We have spent the time since Tuesday, last visit 10 here, discussing this with our system analysts,-and that's-11 probably our best estimate at this point is that the'30 to 50 12 percent reduction may be achievable, and that would be very ( 113 significant if those' kinds of reductions were achievable. h 14 (Slide) l 15 'MR. SIEGEL: If we were to go forward, and I think 16 this is very consistent with the previous presentation, there 17 is a process that one has to go through, and the process 18 really is, as was stated earlier, is to determine the next 19~ limits break size, new mass energy releases, new temperature i 20 time curves, define new conditions within the condition, and j J 21 after that, evaluate effects on ECCS requirements. i 22 Well, I think there is probably a good technical I o J 23 agreement between the staff and ourselves as to what the l 24 proper process would be. This is not necessarily a very 25 simple or short process because you do have to start [} j HERITAGE REPORTING CORPORATION -- (202)628-4888 l L

221 1 eliminating breaks in the sequential order, and as I stated 2 earlier, the main steam line right now is our next candidate 3 and we feel confident, though, that the main steam line would 4 he a good candidate and results would probably be successful. 5 (Slide) 6 MR. SIEGEL: We are aware also that some utilities 7 have been able to demonstrate leak before break on their surge 8 lines, and we consider that a good candidate. 9 (Slide) 10 MR. SIEGEL: Four areas I would like to talk about 11 that I think are very important for our discussion today is 12 the areas where potential benefits of extending the 13 applicability might be, 1 () 14 The first one I will talk about is containment 15 building integrity, EQ of equipment, emergency operating 16 procedures, and finally, plant equipment and operational 17 flexibility. 18 (Slide) 19 MR. SIEGEL: In the area of the containment 20 building, as I stated Tuesday, the principal concern is the 21 Appendix J test pressure and its effect on containment 22 integrity. It's a structural integrity question in large 23 part, even though there are some cost and man-rem 24 implications, and I have references which I would like to talk 25 about, and unfortunately I don't have a slide for. HERITAGE REPORTING CORPORATION -- (202)628-4888

4-222 1 Two references in particular--one.isithe EPRI plant. 21 -life extension pilot studies,-in particular the one performed- .O ~ 31 for-Surry PWR.. .That was an EPRI report-NP 5289 i'ssued in July 11-

of 1987, and one of the findings in'that' study was that during 5-

.the pressure testing, and the? visual examination.that takes 6 place during the pressure testing, small cracks-in the 7 concrete were visible opening at about.a pressure.of 26 psi. 8 The actual test pressures was at 45 psi, 9 In the EPRI report, there were two concerns'that are. L l '10 ' stated as a conclusion. One is that exercis'ing the cracks, 11 there are some concerns that'you might get incremental crack 12 growth. That is not ASME Section 3 type of fatigue concern. 13 It is more of crack growth fatigue type of concern, and,the-() 14 second concern was.that when'a crack is opened, there is a' 15. moisture entrapment, then the pressure is released, the crack 16 closes, and there is the potential for corrosion. 17 Other industry experts I have talked.to from my work 18 'in ASME Section 11 concur. They don't think that is a unique-19 finding, and so one of the benefits that we see in the area of 20 containment is by reducing the pressure, that time of 21 phenomena is minimized. 22 Now the present design of the containment is done 23 according to all the applicable rules. It shows the 24 containment is good for a greater than the expected life of 25 the plant. This type of concrete crack, however, is typically 1 HERITAGE REPORTING CORPORATION -- (202)628-4888 w-___--____-__-_-_____________________-__________ _A

'b oj d 223 1 N 1~ outside;the' bounds of. correct fatigue analyses and it is er j i " r'* .2 Lseparate. type of consideration..The'American Concrete' h I -3' Institute-has also expressed concerns'over thisLtype of. ) 4: concrete cracking phenomena. 5 EDR. SHEWMON: .The pressure that-it is exposed;to J i 15 comes from some required task, is thet your point? 7' MR. SIEGEL: Yes. The test pressure is based on- : 8 DR. SHEWMON: How often'is it tested?' 9 MR. SIEGEL: I believe it is,-a test ~presentlyLis 10 required'four times in each ten-year interval. Is that 11 correct? Three times; thank you. 12 IMt..SHEWMON: Okay. Fine. Thank you. 13-DR. KERR: The implication is that the test pressure ) 14 'would be-decreased significantly if used leak before break. 15 MR. SIEGEL: That is correct. '16 DR. CATTON: That runs contrary to Brookhaven. 17 DR. KERR: In keeping.with the Brookhaven results. 18 MR. SIEGEL: In terms of the pressure reduction 19 being achievable? 20 DR. KERR: Yes. 21 MR. SIEGEL: That's a correct observation. We feel 22 the Brookhaven results did not accurately represent the 23 effects of slower pressure build-up due to smaller breaks and 24 the effect of spray systems and coolers in containment. 25 DR. KERR: If that were taken into account, and it -.O HERITAGE REPORTING CORPORATION -- (202)628-4888

fn '224 H would-needLto.be' taken into account to achieveLthe results to 2 1 2 whichiyou refer? 3 MR. SIEGEL: That is correct. ;To' keep in 4 perspective, the slide put up about the process required which 5 talks about finding the next smaller break and.doing these 6. analyses is we agree the first step that.would have.to be done 7 before these benefits would be achievable. 8 DR. KERR: Thank you. 9 MR. SIEGEL: The'second reference I would;1ike to 10 refer.to in this case is a 1985 paper Its title is the new 11 Belgium position on containment. It was presented in 12 Europe--new Belgium position on' containment leakageftesting. 13 I'm sorry, and in Belgium the new procedures that they have. () 14 recommended is that containment buildings be pressurized 15 during-these periodic tests to one half what they call the 16 accident' pressure', which is one half of what I referred to as-17 45 psi earlier. 18 They also recommend a copy of the testing and i ~19 therefore at lower pressures, as part of their program 20 development, in this paper they indicate that such tests are 21 now present1y also being performed in France, and the three 22 benefits that are referred to in the paper are the test 23 duration is shorter and therefore it is simpler for the 24 project. They use the word danger, and I am using that only I '(]) 25 because that's what was in the paper, l l HERITAGE REPORTING CORPORATION -- (202)628-4888

225 1 They talk about the safety implications of the 2 equipment, and the containment and that lowering the pressure, 3 they feel that they have reduced what they are referring to as 4 the danger. 5 Finally, they make the comment that they feel that 6 che lower pressure is more representative for what they are 7 trying to get out of the test program in terms of the 8 potential leak rates and actual environments, and so it is not 9 a new thought in Europe. It is being done, and I think we 10 would concur it seems to make good engineering sense. 11 MR. CARROLL: Belgium would still do a full pressure 12 test and--initiall to to start up? 13 MR. SIEGEL: They were, the paper was addressed to () 14 operating plants, and so I guess I won't know how to comment 15 on that, and at this point we are certainly not recommending 16 that design bases be changed. I don't think we have done 17 enough work to recommend that, so my comments, I am also 18 addressing to operating plants. There will be obviously some 19 major impact on new containment designs if this, if this 20 actually results in a change in the design basis. 21 (Slide) 22 MR. SIEGEL: That's a little bit more detail than I 23 presented on Tuesday on containment because it was c?. ear that 24 with the Brookhaven National Lab analysis that showed no 25 reduction in pressure, it caused a little bit of confusion I HERITAGE REPORTING CORPORATION -- (202)628-4888

226 1 think. ("y 2 The next area that I would like to discuss is EQ of .V 3 equipment, and it has a couple of different facets to it, and 4 I think this was also some area of confusion on Tuesday, i 5 If we assume we go through the process I described 6 and we define new containment pressurization, both rates and 7 peak pressures, then I think, as Mr. Bosnak stated, there 8 would be obviously some benefits to the industry in using more 1 9 standard equipment, perhaps standardized required maintenance l 10 within and without containment. 11 One thing that people have shown a lot of. interest 12 from when I talk to them on the utility side tends to lengthen 13 the maintenance and replacement intervals. A() 14 DR. CATTON: When you qualify equipment, it is just 15 you autoclave it, don't you, at temperature, humidity, 16 pressure, at time? 17 MR. SIEGEL: Some of the, some of the tests actually 18 bathe an instrument in a harsh steam environment suddenly 19 applied. 20 DR. CATTON: But nevertheless it is the, the 21 environment is, it's basically at rest relative to whatever 22 you are testing? It is autoclave, yet you are dealing with 23 circumstances where the atmosphere is going to be moving 24 around pretty violently, yet you are arguing for reduced I l r^g 25 conditions for the qualification of the equipment. j %-) HERITAGE REPORTING CORPORATION -- (202)628-4888 i

227 1 Are you going to go back and take a look at what the 2 real environment is? 3 MR. SIEGEL: The word real I think is an interesting 4 word. I think certainly one would have to go back and look at 5 predicted environment, would be based on new assumption. 6 DR. CATTON: In 1976, in the HDR containment in 7 Germany, they did some tests where they opened up a steam line 8 cr something. When you walk through that containment 9 building, it is really a shock, and it's the combination of 10 high temperature steam and flow. The high temperature and the 11 steam by itself is not near as devastating as the combination, 12 and that synergistic effect has been ignored, so I don't know 13 how you can argue for doing anything with the qualification of () 14 equipment until you address the whole problem. 15 MR. SIEGEL: I would agree with your statement a 16 hundred percent, that if we are going to revise standards, we 17 should do it in what we think is the most technically 18 appropriate way. I certainly wouldn't disagree with that. I 19 think the present standards, though, have some shortcomings 20 that have resulted, in our presentation have resulted in some 21 surprising effects on service margins and plants and 22 complications in plants that I don't think have been fully 23 appreciated until we started looking into this, dnd I think, I 24 understand the issue you are raising, but I think on the other 25 side there are some surprising issues weighing in the other [} HERITAGE REPORTING CORPORATION -- (202)628-4888

228 11 idirection. {) 2-DR. CATTON: Probably are. I'm just not convinced 3 that the, that you are going to come out with reduced-4 environmental qualification requirements. ILthink if you;do: 5 the problem right, they will be more severe. ~ 6 MR. SIEGEL: Okay. I guess at this point right now- .1 7 -with what we know, what I could say is.I would anticipate: 8 lower pressure / temperature profiles in the containment.. I 9 understand your point, though. 10 MR. SIEGEL: Lengthening of the maintenance 11 replacement interval is anLimportant one to the utilities from 12 a man-rem reduction in maintenance cost point of view, and it' 13 is based on a hypothesized pressure / temperature environment () 14 'that an instrument has to function in after some event,.and so 15 the total profile that comes down the length of service, 16 especially for some of the non-metallics, would lengthen and 17 that would result in this longer useful life: prediction for. 1 18 some equipment. 19 Spare part planning in the industry is quite a 20 challenge. With a lot of unique components with venders 21 changing, lot of complexity, and I think the benefit we see ) 22 here is one of simplification, and I guess I would think 23 simplification adds to reliability. 24 Increased part interchangability, of course, would 25 just be inside containment, outside containment, or more (} HERITAGE REPORTING CORPORATION -- (202)628-4888

e 229-1 standard parts, and there.are other industries, the. chemical 2 industry, petrochemical industry, that!uses;a lot of .3 - components with good histories of reliability that would just-4 allow our industry to use some of that experience.and perhaps-5' benefit from it. 6 These last.two items are items that I find every 7 ' time I start to talk about them generally create' a.certain 8 amount of confusion until we get into the conversation a 9 little bit more, and they are probably two of the most 10 important ones. 11 The testing that is presently done on the -12 instruments is to impose this harsh environment.in essentially-13 a step change type of fashion. Ten seconds'is the number we f() l14-hear a lot. When they test it they might do it faster than-15 that. 16' What we have found in some of the testing is there 17 are two factors that lead to instrument uncertainties..One is 18 .the ramp rate, and one is the final pressure / temperature that t: 19 the instrument has to live in. 20 The ramp rate can be extremely important. In a key 21 transfer thermal expansion calculation I was involved in a 22 couple of years ago in a pressure transducer what we found is 23 that with a 10 second ramp rate, the outer portion of the 24 instrument, of course, would react to the new thermal ] environment very rapidly, the inner portion hadn't felt it 25 HERITAGE REPORTING CORPORATION -- (202)628-4888

. 1 230' L li ' ye t.. You--were3actually getting internal; differentia.1 thermal n _ growth in the instrument.- It turns out1that was one of sort ~~ 2 E 3 '3 of the assumed uncertainties obviously with a slower: ramp. a 4 . rate, and'even the Brookhaven. studies indicated that if there= '5 would be a slower ramp rate,-that effect would. tend to be 6 minimized and more. realistic, so-regardess-of the fact that j .7 which pressure / temperature limit you go'do, just the fact of 8' changing the ramp; rate would?have.a significant effect on 9-tested uncertainties on instrumentation. 10 DR. CATTON: Here is a good example that flow will 11 have impact.- If I decrease the ramp rate, increase the~ flow-12 rate. I will get the same thing,~a heatLtransfer coefficient 13 as well. It's called the chill. factor when it.is cold. .1 ( ~ 14 MR. SIEGEL: I understand exactly what you.are 15 saying. In our analysis we assumed' conservative outside heat. 16 transfer coefficients. I know in our analysis that-it would j 17 have been quite a beneficial effect..Our analysis' matched 18 quite well with the test results that we were trying to 19 correlate it with.. 20 MR. MICHELSON: Aren't you beginning to-suggest a 21 rather finetuning of the whole situation, in using codes.now j 22 that you understand local conditions to,.with great precison 23 the instantaneous rise is a reasonable one to apply in 24 testing, *easonably instantaneous, but if you start using slow 25 ramp rate, then you have to show how you know they are slow, j HERITAGE REPORTING CORPORATION.-- (202)<28-4888.

i 231 { and I'm not sure you can do that easily. It depends op many, 1 2 many.loca1' factors around the instrument. f-L.-) \\ 3 MR. SIEGEL: Well, I guess I would have two 4 comments. One is I am not recommending anything today because 5 we have not done the detailed work to support that. 6 What I am just suggesting is that here is one 7 phenomena that I have observed that I believe to be a very 8 sensitive one. 9 The second one is when you talk about finetuning, 10 and I have done a lot of fatigue' analysis say on metal 11 components,'the assumption of a step change which is done, i 12 quite often simplified the analysis, is really quite a i 13 dramatic assumption, and that the difference between the step (') 14 change and a one minute ramp rate on a thin wall metal 15 component is quite dramatic when you look at heat transfer 16 characteristics, thermal growths, differential thermal growth. 17 That is, I don't consider the step change in one minute to be 18 a finetuning. It really is quite a large difference in I 19 results in terms of behavioral response. 20 MR. MICHELSON: Difference in results can be l 21 dramatic, but of course you have to, unless you are going to 22 insulate or something to slow it down, you are going to have 23 to prove that you know rather precisely what the rate of 24 change is. fg 25 MR. SIEGEL: I would certainly support the position - (,/ HERITAGE REPORTING CORPORATION --- (202)628-4888

232 1-

that we should have a good technical basis before we change

('p 2 the findings. \\s 3 DR. CATTON: You may be putting a technical-4 requirement on yourself that is going to be awfully difficult 5 to satisfy. Your instruments are going to become very 6 location dependent. 7 DR. KERR: Let me remind you he is not proposing 8 anything yet. He is just suggesting some change that need to 9 be looked at further. I would be reluctant to have either us 10 or him try to design these tests at this point. 11 MR. SIEGEL: Thank you. There is one thing, 12 however, that I would like to emphasize. I am about to turn 13 the presentation over to Tom Williams from Arkansas Power and () 14 Light for the rest of our slides. He will be expanding on 15 these two issues and how they relate to other aspects of plant 16 operation, and the point is this, that the step change 17 assumption and large break LOCA assumption which were made 18 which appeared to be conservative at first glance, and'most 19 people view it that way, as we looked into this in more detail 20 and we look at aspects of plant operation, and I chose one, 21 containment pressure, and I believe you will see one, 22 instrument uncertainty calculations, don't necessarily, they 23 weren't necessarily pro-safety assumption. I am not saying 24 they were necessarily anti-safety assumption. I don't think /"% 25 the full import of those assumptions has yet been established, V HERITAGE REPORTING CORPORATION -- (202)628-4888

233 1 and they appear to be quite significant, and when we talk 2 about it, we talked about it on Tuesday, I realize it is a 3 little bit confusing, we talked about operating margin, 4 overly-conservative instrumentation errors, and as we continue 5 to look into it, as Mr. Williams is about to continue with, 6 you will see it is a major assumption. It is not a minor 7 assumption, and so with that, if I could, I will invite Tom to 8 come up here and continue talking about further aspects of 9 what we talked about on Tuesday. 10 MR. WYLIE: Again, the benefits derived as you 11 indicate may be, are the results of slower ramp rate allowing 12 the sprays and other systems to come on and reduce the 13 environment where you can use standardized components, isn't () 14 that right? 15 MR. SIEGEL: For the containment integrity issue, 16 just using the slower, just allowing the sprays to come on and 17 having the total less ultimate pressure, a 30 percent 18 reduction of pressure would have in itself just a positive 19 effect on the integrity of the containment structure over 20 time. 21 MR. WYLIE: Let's take transmitters, things like l 22 that. 23 MR. SIEGEL: I'm sorry. I thought you were making a 24 general comment. 25 MR. WYLIE: It is general. This is a general HERITAGE REPORTING CORPORATION -- (202)628-4888

-234 1 statementII think. .2 MR..SIEGEL: Yes' '3 MR.. WYLIE: Isn't'that, I-mean-- n 4 MR. SIEGEL: What was your-- 5 MR. WYLIE: I am saying that.in order to do what you 6 -say, achieve these things, that you'are really~saying that you I 7 are allowing the cooling systems to come on and' allow you'to: l 8 get into the. area where you can use standard components, isn't. 9-that correct? I mean that's the assumption I guess, 10 'MR. SIEGEL: Sure.- And I will state it again. We '11 haven't'done a detailed calculation of containment pressure 12 and; temperature profiles other.than perhaps ten years ago, and- .13 : I am sure if we did.it today, we would do it in a I E 14 sophisticated way and different technologies, but our best 15 assumption at this point, best judgment in talking to.about I 16 15 different people _back at Combustion EngineeringLwho 1 17 couldn't all come today is that 30 to 50 percent reduction in 18 final pressure and temperatures would not be a surprising 19 result based on the. realistic analysis. 20 DR. KERR: Mr. Siess, do you have a question? 21 DR. SIESS: Have you looked at what the effect might

1 22

.be of changing the environmental qualification criteria in 23 terms of the risk from severe accidents? H24 MR. SIEGEL: No. We have not. 25 DR. SIESS: Would you expect to? It seems to me the .{ ) ( HERITAGE REPORTING CORPORATION -- (202)628-4888

235 1 environmental qualification is somewhat like the containment 2 design. We made certain assumptions on containments. We get 3 a design pressure. We design a containment and we look at 4 severe accidents. It turned out to be a pretty good 5 containment, not that we designed for it, and does anybody 6 through, on some of the equipment qualification--equipment 7 that is qualified for some arbitrary release might turn out to 8 be able to survive a severe accident whereas equipment that is 9 qualified at some lower level, you might have to say no, it 10 can't, it can't operate during a severe accident, changes your 11 risk profile. 12 MR. SIEGEL: Well, I understand-- 13 DR. SIESS: Assume that what we are postulating here (]) 14 is a design basis accident, it is not going to be when we cet 15 through, and it is really not what we are concerned about. 16 DR. SHEWMON: Part of wh.at he is saying is that the 1 1 17 usual convenient assumption of instantaneous change is 18 damaging and probably unrealistic and that certainly a severe 19 accident isn't going to develop in a split second, either. I 20 would guess that-- 21 DR. SIESS: No. My point was that something that is 22 qualified for this might be qualified, might be better able to 23 survive a severe accident. I don't know. I asked whether it 24 has been looked at and there are other benefits. You might 25 have less likelihood of everybody getting to a severe HERITAGE REPORTING CORPORATION -- (202)628-4888

___=_ 236 1 . accident, but to show a net safety benefit, we have'got'.to y( 2 look'atlthe whole picture. 3 MR. SIEGEL: I would certainly agree with that, th'at 4' if.we change the criteria, that the analysis should be quite 5

thorough, and I don't-think there is any disagreement on.that 6

issue; 7 I think what I am saying here is that we,.we-feel-8 that there are a number of safety benefits, cost benefits, D 9 man-rem reduction benefits that the industry may be able to 10 pursue,.and the more we look at it, the'more we feel there are. i 11 probably larger benefits than anyone in this room right now 12 would anticipate because the more things we'seem to find. It-13 seems to have, that some of these assumptions seem to have ~( ) 14 their finger in all' areas of plant design and plant operation, q l 15 plant procedures, many times in a negative way, and Tom is 16 going to be talking about the-operational' side in a minute.and: 17 I think what we are here to say.today,' though, is that we 18 think we should as an industry pursue these because we think 19 the benefit may be substantial, and we perceive that what is 20 happening with the SECY letter may be a hindrance to that, an 21 impediment to that, and having it out in the open like that we j 22 feel is a pretty good, healthy thing to do, and that's really 23 the only purpose of my coming today to talk about it. j h 24 I am certainly not trying to recommend that, a new 25 design basis at this point. {} HERITAGE REPORTING CORPORATION -- (202)628-4888 l

237 1 MR. MICHELSON: Just so I am sure I understand what 2 you are saying, you said that there might be some safety 3 improvements here, but you're defining safety in terms of 4 safety relative to the conventional design basis accident 5 situation, not to the severe accident situation? 6 You haven't looked at severe accident, in other 7 words, in safety, so your answer, your observation of enhanced 8 safety is somewhat relative to the kinds of things we are 9 thinking about up to a design basis which will be a new design 10 basis in your case? 11 MR. SIEGEL: I have not looked at it enough to l 12 really respond well to your question, and I think it would l l 13 have to be responded to. () 14 In terms of containment structure, and concrete 15 cracks, I can say pretty easily as a civil engineer if I had 16 my choice, I would rather it didn't, and if it is called upon l 17 some day to maintain its pressure integrity under some 18 condition, I would rather have one that was cracked a little 19 bit less than one that had cracked a little bit :nore, and 20 that's a pretty obvious statement that most of us would agree 21 with in that regard. If you postulate a more severe accident, 22 I think my position is stil] a valid one, that I would be 23 mitigating the cumulative fatigue damage with this 24 recommendation of reducing test pressure, and no matter what 25 scenario you follow, we would be better off. O HERITAGE REPORTING CORPORATION -- (202)628-4880

238 i 1: ,RDR.- SIESS: 'Howlmany tests do you make'during the p 2 olife-of:a-plant? 3 MR.- SIEGEL: LThere is a, there'is an initial't'est-4 and then I believe itLis three full pressure tests at every: 5' t'en-year interval. 6 DR. SIESS: Start off at'115 percent of design 7 pressure for'the structural integrity test,.which is pretty' 8 darned good. As I recall,.the integrated' leak. break.testLis 9 at accident pressure, which is probably somewhat less than 10 design pressure by a few percent, and five or :six of 'those. 11 MR. SIEGEL: There is-- 12 DR. SIESS: Are you worried about fatigue? 13 MR. SIEGEL: When I'use'the word 7 fatigue,.I.want you gg /~N. x_/ 14 to understand it. 'The way it is presented it was the issue of 5 '15 in a visual examination small' cracks were observed to-be 16 opening, and that's not--and then close, and that was'the 17 concern. It was not the f atigue in the Section 3 type-of L 18 fatigue sense. It is a concrete cracking type of issue. I 19-DR. SIESS: Who was concerned about that? 20 MR. SIEGEL: That was in the EPRI, that observation 21 was made in the EPRI pilot study on life extension at the l 22 Surry plant over containment integrity and long-term, 23 long-term use. I 24 DR. SIESS: Now you have got me worried about cg 25 bridges, half of the-2 million loads. HERITAGE REPORTING CORPORATION -- (202)628-4888 L_? ._ __ A

239 1 DR. KERR: If we had to worry about bridges, we 2 would really have problems! 3 DR. SIESS: They know something I don't. 4 MR. CARROLL: Chet, you weren't here, Chet, but the 5 other half of that was the opening up, getting moisture in, ~ 6 closing it up, and having moisture work on the rebar. 7 MR. SIEGEL: That's right. That's the other half of i 8 the concern. l f" 9 MR. CARROLL: I think that's real. 10 DR. SIESS: Sure it's real, but is it true of every 11 structure that has ever been built? The pack is there. Open 12 it up every three years-- 13 DR. KERR: Ara there further questions, Mr. Siess? () 14 Thank you, Mr. Siegel. 15 MR. CARROLL: Let me see if I understand your bottom 16 line. 17 What you are really saying is you would like to keep 18 your options open and you think that the SECY paper tends to, 19 your reading it at least tends to foreclose some of them? 20 MR. SIEGEL: That is exactly correct. We think it 21 is important that, we think it is important enough issue that 22 the industry should continue to investigate it, and I guess 23 what I perceive at least is an impediment to utility support 24 to pursue this because of uncertain environment. 25 DR. SIESS: Can't you do this by the extension [} HERITAGE REPORTING CORPORATION -- (202)628-4888

240 1 route? i r~ 2 MR, SIEGEL: The members of the CE Owners Group, the (,);. 3 utilities have expressed some discomfort with that option. 4 DR. SIESS: I said can't do it. I can understand i 5 they are not wanting to do it. I 6 MR. SIEGEL: Well, I'm up here speaking I guess as a 7 structural engineer, not a licensing engineer, as I said 8 Tuesday, so I don't know how to respond to a question like 9 that in terms of what they chould pursue in that regard. 10 DR. KERR: We should perhaps ask for a disclaimer on 11 the part of staff that any hostility toward new conditions-- 12 MR. SIEGEL: The last slide that Mr. Williams is 13 going to present has a recommendation on it. () 14 MR. WILLIAMS: I'm Dan Williams from Arkansas Power 15 and light. I am a member of the CE Owners Group Steering 16 Committee and Chairman of the Analysis Committee for that 17 Owners Group. i 18 If I could follow up on a couple of things that Ed 19 mentioned before I go on, I have talked to some of our 20 instrument engineers, and they brought up some interesting 21 things with respect to the information on the overhead that's 22 up and the moment. 23 One thing they mentioned to me, the use that they I 24 would like to make of something called smart transmitters. (~ 25 They can't use them because of the EQ requirements that are s. HERITAGE REPORTING CORPORATION -- (202)628-4888

mm- .j 24'1. f( 1. ~currentky'.----in. place. If they were able to lower'the EQ'-

2

.requirementsfsufficiently, and maybe raise the qualification- 'p -3 of the existing smart, transmitters some, they would be able to. 4 .use these. They are more accurate, and would tend to help 5 prevent severe accidents, as was mentioned. They are also,. i 6 you are able to calibrate them remotely, and would reduce-7 man-rem exposure, maintenance on these transmitters. 8 Another thing that was mentioned to me was a quote 1 9 from one of these people's previous bosses who had worked a 10 number of years in the chemical industry. They didn't 11 understand why we have to use all these strange, exotic 12 instruments in the nuclear industry because the ones they use 13 in the chemical industry were ten times more reliable. I am '( ) 14 convinced that he didn't intend that to be a quantitative 15' statement, but an indication that, that we were harming 16' ourselves by restricting our instrument applications to a 17 select group, and there are s'ome specific instances.where we 18 have limited ourselves to single suppliers of nuclear 19' manufar hx4 instruments because of EO requirements. 20 DR. KERR: Mr. Williams, this might lead people to 21 believe that the utility industry always buys the most 22 accurate and reliable instruments available. I have been led 23 to believe occasionally they made decisions based on the i 24 lowest bid. 25 Am I mistaken? [} HERITAGE REPORTING CORPORATION -- (202)628-4888

242 1 MR. WILLIAMS: I am sure there have been cases of 2 that, Dr. Kerr. I haven't personally witnessed any of those. 3 DR. KERR: There do exist various grades of 4 reliability in instruments that are postsible even under NRC 5 regulations. 6 MR. WILLIAMS: Our instrument engineers frequently 7 bemoan the fact that they are not able to buy what they 8 consider to be better instruments because of the specification 9 requirements placed on them because of nuclear application. i 10 With respect to the severe accidents, I should say 11 that there is a balance obviously between the qualification of 12 qualifying instruments to severe accident conditions, and the-13 ability of instruments of less qualification to reduce the n (_) 14 probability of those severe ace; dents, so there is a, clearly 15 a balancing act that has been referred to. 16 Let me continue. 17 CHAIRMAN REMICK: We have to keep our eye on the 18 cloct. There is 30 minutes set aside for a Westinghouse 19 presentation, so move along as rapidly as you can, please. 20 MR. WILLIAMS: Yes. I appreciate that. We--in the 21 area of operating margins, many of the instruments that we 22 deal with have errors tacked on to the set points such that 23 the margin between the actual frequently experienced operating 24 conditions say post-trip, and the actuation of that system is L (V~T 25 significantly reduced. l \\ l HERITAGE REPORTING CORPORATION -- (202)628-4888 1

243 1 For example,.and I have got these up here--I won't \\_i (' 2 go through all of them for the sake of time, but let me d 3 mention specifically that the first one, the safety injection 4 system, really needs to actuate at about 1600 pounds because 5 of instrument errors, and largely that are applied.due to the 6 environmental conditions created by large break LOCA. The set 7 point is actually up around 1850 psi. The plant routinely 8 dropped to in the neighborhood of 1950 psi post-trip. Now we 9 are talking about a hundred psi margin to actuation here as 10 opposed to what could be maybe 200 and 250 margin. This 11 occasionally leads to inadvertent actuation, and inadvertent 12 actuation of the safety injection system significantly 13 complicates what could be a normal post-trip event. This ()j 14 applies to the other, the emergency feedwater actuation system .s_ 15 as well, and to the application in a non-actuation. situation 16 of margin to saturation. 17 MR. CARROLL: You are saying that the 250 degrees is 18 the result of compensating for EQ? 19 MR. WILLIAMS: Largely. 20 DD. KERR: How much instrument drift does one typically see between the calibration of those instruments to l 22 which you refer? 1 23 MR. WILLIAMS: I don't know the answer to that, j 24 DR. KERR: Well, maybe those instruments--but I have 25 seen numerous LERs over the years that refer to significant j (~)/ }. HERITAGE REPORTING CORPORATION -- (202)628-4888

c-7 244 1 instrument drift. f'] 2 MR. CARROLL: Yes. That I think largely, though, C/ 3 that those problems have been solved over time. It was 4 unacceptable instrument drift. I won't name the vender. 5 MR. WILLIAMS: If we go on to reduction of 6 instrument uncertainties in an operating, emergency operating 7 procedure context, we can talk about things such as 8 pressurizer pressure, pressurizer level, steam generator 9 level, margin of saturation, and here again largely due to the 10 environmental effects anticipated as a result of large break 11 LOCA, these errcrs range anywhere from--I am speaking 12 specifically at our plant--errors from 17 percent on the 13 pressurizer level up to close to 30 percent errors on steam (N ) 14 generator--wide-range level. 15 And these can be reduced significantly. To give you 16 an example of that, we talked briefly about the margin of 17 saturation. Now this example is not one that results from 18 leak before break application. Using an example of the 19 benefit of getting rid of large break, in this particular case 20 we were able to get rid of it for reasons other than large, I 21 mean leak before break because of the application of this 22 parameter to only smaller breaks, but we were able to by 23 applying small break conditions instead of large break 1 24 conditions to the calculation of the uncertainties, lower the 25 uncertainties here from approximately at a thousand psi, (~} N-HERITAGE REPORTING CORPORATION -- (202)628-4888 1 j

1245-1 1. approximately uncertainties of 50 degrees.Farenheit to 30 /"T 2 degrees Farenheit.- 's) ' '3 .Now what this does for you-- t 4 DR. KERR: You were able to lowerLit from 15 t'o 30 i 5 degrees? 1 6 MR. WILLIAMS: Fifty; 'what this/does-foriyou in the 7 context of the emergency operating procedures is as you 8 depressurize-- 9 DR. REMICK: Could you stand aside from.the slide?. 1 10 We.can't see it. 11 MR. WILLIAMS: I was' going to try'to mark on the-12 slide. 13. DR. KERR: 'That's okay, as long as you step back 14 aft'er you mark them. 15 MR. WILLIAMS: I have a pointer. Thank'you. In the 16 context-of meeting operating procedure for steam generator. 17 tube rupture, one of the things you try to do is lower your 18 pressure. 19 Now if'this steam tube rupture is a fairly small 20 one, you have control over your pressure differential between 21 primary and secondary and will minimize the leak and any 22 subsequent off-site releases. 23 As you come down this sature2 n line here, the 24 secondary side pressure will be where the, it will be on the 25 saturation line, saturation secondary system, and let's say {) HERITAGE REPORTING CORPORATION -- (202)628-4888

246 L l' this is a 30 degree subcooling line, the dotted line,7which.it 2 is. - TheLsecondary will.have to be'slightly cooler than.the '}. \\ 3 primary to permit you to cool down, and you are not permitted ) 4 because of the 30' degree margin to lower the' primary below-5 that 30 degree subcooling margin mark. ] 6 Now that'gives us a pressure differential to feed 7 the leakage in this range. The marker is'not working 8 particularly well. d 9 If we had a 50 degree subcooling line, then at the.

j 10 same primary temperature, you can see we would have a 11 significantly larger delta P, more leaks at the break,.more 12 off-site releases, so this is, this is an example _of the kind 13 of benefit that can be achieved by, that may not be really.

() 14 obvious, by lowering the, getting rid of the large break'LOCA, 15 These kind of things, the more we think about them, 16 as Ed said, the more things tend to crop up. I spoke to our. 17 instrument engineers this week, and the guy said you know, I 18 really can't even begin to think of all the ways because it is 19 so inherent, so the tentacles of large break LOCA reach out in 20 so many ways and go into the things that we do, I can't think 21 of all the impacts we have. They are tremendous, and all of 22 the bad things that large break LOCAs do for us, and I don't 23 think I have thought of them. I don't think any of us have. 24 This is one reason we want to continue to pursue this line. 25 I mentioned Tuesday the isolation of safety (} HERITAGE REPORTING CORPORATION -- 202)628-4888

247 l 1 injection techs during a steam generator tube rupture and the 2 necessity because of the large break LOCA of the great 3 interlocks in preventive measures to isolating these tanks. 4 Now if those could be relaxed on that isolation 5 valve, it would eliminate the necessity during a larcer steam 1 1 6 generator tube rupture of the operator having to leave the 7 control room, run down to the local motor control center, hold 8 in the contactors to close that valve in order to continue the 9 depressurization and stop the off-site releases. 10 We can focus on more realistic event conditions. We 11 used to have--put the slide back up. We used to have separate 12 large break LOCAs, small break LOCA procedures. Since we have 13 gone to symptom-oriented proccdures, we have a loss of llh 14 subcooling margin within a single emergency operating 15 reocedures at our plant anyway, but it has to accommodate 16 large break LOCAs and small break LOCAs better. It could 17 focus more directly on the more realistic smaller breaks. 18 If we were to eliminate large break LOCAs, bottom 19 line, as we indicate here, in things such as steam generator 20 tube rupture, we can reduce off-site releases, minimize 21 operator confusion, simplify the emergency operating 22 procedures, and operators, in talking with them, I have worked 23 with them quite a bit in the last several years, take the 24 emergency operating procedures with just a little bit of grain 25 of salt because they are fully aware that they have to ggg HERITAGE REPORTING CORPORATION -- s202)628-4888

248 1 accommodate-large, the design around accidents that they are 2 -convinced are preposterous; by concentrating on-things a 3 little more realistic, that it would increase their l 4 credibility. 5 CHAIRMAN REMICK: I can only allocate you about 6 another six minutes. 7 MR.. WILLIAMS: All right. Thank you. Let me go 8 quickly through these. 9 (Slide) a 10 MR. WILLIAMS: We would anticipate the potential for 11 reduced requirements, and LOCA analysis may be reducing the 12 number of safety injection tanks that are required to be part-13-of the operable--reducing the requirements on the isolation, (]) 14 prevention of isolation'of the safety injection tanks, the. 15 -volume and pressure requirements, and the safety injection 16' tank, possible reduction of LPSI pump operational 17 requirements, both the performance requirements and the number 18 of pumps required to be operable. ' l 19 Performance requirements would increase the margin 20 that is available for what is required of those pumps. 1 21 Containment building cooling capacity could potentially 22 decrease area of sprays and coolers and increase margin there.- 23 We have talked about the emergency diesel generator 24 system reliability from a testing standpoint, but even from an 25 actual real challenge standpoint, the slower-- HERITAGE REPORTING CORPORATION -- (202)628-4888 .-_-_a

'249: ] l 'l DR. KERR: ' Mr. Williams, put yourself-in our shoes ) I f(") 2 and ask yourself what your response would be to a' listing of a- %) -3 lot of potential' benefits without any demonstration that these 4 . benefits exist. How would you react?' 5 MR. WILLIAMS: I am sure that we pursue lthe 1 6 demonstration that these benefits exist. 7 DR. KERR: JWell, everything I have heard from the 8 NRC staff would say that they would encourage.you.to do that. .i 9 Do you not believe them? 10 MR. WILLIAMS: I have heard more encouragement today .11 than I did earlier in the week. I have not been able to read 12 the SEGI letter. I don't know what it says. We are 13 proceeding entirely on perception in that area. r I 14 DR. KERR: You say the SECY l'etter. You mean the i 15 SECY itself? 16 MR. WILLIAMS: Yep. We have had to proceed on the 17 perception that we have gotten that they-say it is not worth-l 18 pursuing any more, let's drop it, and all we are suggesting' 19 is, as I will get to in just a second, is that-in fact I will 20 just go on because of time, is that we continue to pursue 21 this. 22 The staff worked with us to define what information 23 would be necessary in the future to proceed with rulemaking 24 that might be required, and in particular, I am encouraged by 25 the modification of the way they have expressed their position

(]J HERITAGE REPORTING CORPORATION -- (202)628-4888 i

250 1 on this and the presentation today from that that was 2 presented Tuesday. - s. 3 The final slide of Mr. Bosnak's presentation is very 4 encouraging, and I would, I would encourage that this 5 position, this willingness to continue to pursue the 6 application of leak before break in things such as ECCS and EQ 7 containment pressure testing requirements, et cetera, that the 8 position expressed today be clearly expressed in the 9 Commission position that may be generated as a result of the 10 SECY. 11 MR. MICHELSON: What do you mean by position, 12 Commission position? Do you mean a new rule? 13 MR. WILLIAMS: No, not at this time. () 14 MR. MICHELSON: Or do you mean policy statement? 15 MR. WILLIAMS: Not at this time. 16 DR. KERR: He means a policy of glasnos! 17 MR. WILLIAMS: I think that's a good way of 18 expressing it. 19 MR. MICHELSON: You want some kind of encouragement 20 because at the subcommittee meeting I got the impression at 21 least that the encouragement on the industry part was defined 22 as a rule change. Maybe I misunderstood. 23 MR. WILLIAMS: I think we mis--we led you to 24 misunderstand. 25 MR. MICHELSON: You really aren't meaning that? You HERITAGE REPORTING CORPORATION -- (202)628-4888

251 1-are meaning some kind of a verbal statement of encouragement 2 from the Commission? 3 MR. WILLIAMS: Right. If you refer back to Mr. 4 Bosnak's last side stating that the staff encourages that 5 industry develop quantitative information which will 6 demonstrate safety or the benefits which lead to 7 simplification of operation or design when the leak before 8 break is used for EQ and ECCS. 9 We wouldn't necessarily limit it to EQ and ECCS,-and l 10 we would request that the staff would work with us to define i 11 the information that needs to be developed to support a 12 rulemaking in the future. Not now, now not the rule change at 4 13 this point in time, but that we work hand in hand to develop U r" 'y j% 14 the information necessary for those changes in the future. 15 DR. KERR: You might consider just overwhelming them ) 16 with information. They couldn't-- 17 MR. WILLIAMS: That has been tried before, and they 18 can always find something else that needs to be done. 19 DR. KERR: I have seen cases in which people 20 persuade the staff to do things by valid information, and I 21 can give you examples. I think it is possible. 22 MR. WILLIAMS: We will have to take that into 23 consideration. 24 DR. KERR: Well, you should, e' 25 MR. WILLIAMS: But I would like to encourage that N)s HERITAGE REPORTING CORPORATION -- (202)628-4888

'252 1 whatever documentation is produced as a result of. resolution' 2 of this-issue at this point in time' clearly express what'l' Q)c fs ?3 consider to.be an encouraging view of-the staff as-expressed' -4 in today's presentation. 5 DR. KERR: Something.like we.are from the 6 government,-we are here to help you?. 7 MR. WILLIAMS: Absolutely. l 8 .MR. MICHELSON: Is the Owners Group going to make a 9 presentation to the Commission when this is presented to the 10 Commission? 11 MR. WILLIAMS: We would consider that possibility,' 12 yes. 13 MR. MICHELSON: You know, if what you are telling us; {)- 14 is your wish, then certainly we need to convey it in some 15 fashion or if you can do it'by letter to the' Commission-- 16 CHAIRMAN REMICK: Thank you very much, Mr. Williams. 17 MR.. CARROLL: So you are happy with the staff words 18 except you don't like the limitation of LBB is used for EQ and 19 ECCS? Strike those words out of there? 'I 20 MR. WILLIAMS: Right, and we would like for that 21 view to be expressed beyond today's presentation very clearly. 22 DR. SHEWMON: Sir, I guess if we talk about where 23 the effect would come and dynamic effects are already covered, 24 EQ and ECCS were covered, can you give me shorthand for a 25 couple of other areas that are options if possible? .g v HERITAGE REPORTING CORPORATION -- (202)628-4888 i _-__-___ _ ____ _ A

f 253 1 When you say you don't want to live with the EO, 2 ECCS, that was sort of my universe. s. gg (,,/ 3 MR. WILLIAMS: The containment testing, for example, 4 is not EO or ECCS. 5 MR. CARROLL: MOVs. 6 MR. WILLIAMS: I would think a good example of other 7 areas we haven't thought about yet because-- 8 DR. SHEWMON: Bob tended to sweep MOVs under dynamic 9 effects. We may have a new interpretation to "ou today. I 10 don't know. 11 MR. WILLIAMS: But I think even coming--which I 12 hadn't thought of the MOVs. I think it is an good example of 13 the many things that we would all discover that as we continue () 14 to pursue that, we really hadn't thought about yet, the 15 culture surrounding large break LOCA is so prevalent in what 16 we do. 17 DR. KERR: Our next speaker is Mr. Hirst from { 18 Westinghouse Corporation. I hope I have the name spelled 19 right. 20 CHAIRMAN REMICK: Mr. Hirst, we will need to keep on 21 schedule, if you can pace yourself inyour presentation, i 22 please. l 23 MR. HIRST: I don't think the presentation will be 24 longer than 30 minutes. Depends on the questions I guess, i r-25 (Slide) C)' HERITAGE REPORTING CORPORATION -- (202)628-4888

254 1 MR. HIRST: Brian McIntyre made the presentation i f's 2 Tuesday, and he was unable to come. I am standing in his L) 3 place. 4 Basically these are the things we are going to kind 5 of look at, is the, let's see, what we are going to cover, 6 what the interpretation of the rule, proposed rule change is, 7 what the current LOCA analysis considerations are, what the 8 effect is on the safety injection system, impact on 9 containment systems and environmental review, what the impact 10 is on new plant designs, and our conclusions. 11 (Slide) 12 MR. HIRST: Basically we looked at on the 13 Westinghouse plants how they were designed, and what the o) 14 impact was on the operating plants. We looked to safety f 15 injection systems, high-head low-head accumulators, 16 containment systems, the fan coolers, and the aux spray, 17 environmental qualification effect for temperature and 18 pressure, what the potential impacts were on new plants, the 19 approved Appendix K ECCS analysis models, and best estimate 20 methodology that we have got introduced already. 21 (Slide) 22 MR. HIRST: Now the present, the present rule as it 23 is currently changed, used the leak before break to remove the l J I 24 dynamic effects. There have been very few applications where 25 they have been used for the auxiliary lines and below. 1 HERITAGE REPORTING CORPORATION -- (202)628-4888

255 1 Basically it has been the main loop, and they were analyze'd 2 for the effects of the branch lines breaking. Proposed change ,g V 3 is to demonstrate the, the effect on the ECCS performance for 4 all breaks, up to and including the largest one not 5 dispositioned by the leak before break, and then the 6 containment analysis EQ would consider ruptures in carbon 7 steel steam lines up to large break dispositioned by leak 8 before break, so these are the things that we looked at. 9 (Slide) 10 MR. HIRST: Now if we look at the current LOCA 11 analysis, you are required to demonstrate that, the 12 performance for a spectrum of breaks for all sizes required 13 for the Appendix K. There is a separate evaluation model used () 14 for large break and small break, and large break is defined as 15 breaks larger than a square foot where flood behavior is 16 dominated by the inertia effects of the flood rushing down. 17 That really dominates. 18 We have the intermediate breaks which are where the 19 break is less than a square foot but greater, equivalent to an 20 8 inch pipe, which are influenced by inertia and gravity and 21 they have received limited attention because basically we have 22 shown that they are governed by either the large break or the 23 low one, and then we have small breaks which are equal to or 24 less than 8 inch break, and the flow rates are really slow and 25 you get distinct mixtures and levels in the analysis model. HERITAGE REPORTING CORPORATION -- (202)628-4888 1

256, 1

(Slide) i '2 MR. HIRST: Now'what I have'got here which I guess fgV 3-was not' presented last Tuesday, what I wanted to do is mark 4. some things on that, was'the, basically this'is the 1.0, 1.7, 5 .6,,.4, and this is the double-ended full cold leg break, so 6. your.large break generally comes down through here and that's 7 your Satan codes, and what we are going through is COBRA / TRAC ~ 4 8 and what we have'got here, this is basically, this is a 1 9 inch, 2 inch, 3 inch, 4 inch, 6, 8, and this is a 10 inch, 10 okay, and the small break comes down in here, and that's, this-11 is--I'm sorry. Was there a' question? 12-DR. SHEWMON: One of the' disadvantages.of being 13 left-handed is working on the right-hand side, you need'to .() 14 step back and let people see what you wrote. 15 MR. HIRST: I wanted to put it on first and ther, 16 step back. Okay. 17 This is basically--focus this a little bit. Okay. 18 Break size on the bottom hero', and peak clad temperature 19 basically; the small breaks were in the 1200 to 14, 1600 on 20 peak clad temperature, and the. breaks were up here at 2100 21 basically. 22 If we eliminate large breaks, this area in tere does 23 not have, a whole lot of the codes are not really : 24 developed to handle these, so this may have to be, a nau area l 25 may'have to be developed if you eliminate all of these Jarge HERITAGE REPORTING CORPORATION -- (202)628-4888 _ _ ~

257 1 breaks. Basically we.have'said hey, if we are covered by this l I l 2 one, then we are okay. We get down in the small breaks, we 3 are over here, so that this is a potential pitfall I think if 4 .you eliminate the large breaks. 5 (Slide) 6 MR. HIRST: If you look at the safety injection 7 system, its capability to mitigate the the core for the core 8 thermal transients for spectrum of breaks, large and small; 9 all the major components perform a significant function 10 throughout the large break size spectrum. We get that the 11 high-heads primarily function to mitigate the small breaks, 12 two to four pumps, depending on the plant. You're at 1400 psi 13 chutoff head. Since the GDC 4 does not affect the small () 14 breaks, you would have no relaxation in the high-head 15 performance. Okay. That would still be a requirement. 16 (Slide) 17 MR. HIRST: Okay. The accumulators are a. source of 18 high pressure in the small break for the Appendix K analysis, j 19 so that would still be used. Many of the small breaks are 20 controlled, the LOCA terminated and controlled by the 21 accumulator injection, so you would still need the 22 accumulators, so the accumulators would still be retained by 23 the current plants independent of whether the large break is 24 there or not. We still need accumulators. fg 25 Also it is used to refill the reactor for O HERITAGE REPORTING CORPORATION -- (202)628-4888

p; r y.y 258 1 . intermediate break 1LOCAs, ^ so if there is a need for.that,'and 4 1 2 since'they are passive, they are valuable in probaba'listic jf' 3 assessments for ECCS behavior. L4-(Slide) 9 5 MR. HIRST: So based on that,'you know,fwe still. .j 6 think the accumulators need to be there. However,_if we'just-7 got small and intermediate,-we might be able to relax the set-i 8 points, may be.able to operate with one accumulator out of 9 service, one out of N, depending on.where they are, which set y 10 . points are in the : capabilities--if we don' t have any large - 11 breaks. -12 The low-head performance. requirements could be 13 impacted if we would remain mitigate the surge line.or similar ' () id sized breaks. We are talking about the aux lines, the 15 auxiliary lines on the main loop, and the low-head flow is 16 sometimes needed in small break cases to augment high-head 17 injection when the accumulators are empty, so there is 18 sometimes a need for those. 19 (Slide) 20 MR. HIRST: And then on top of that, the low-head 21 pumps are used post-LOCA, for long term, and most of the 22 Westinghouse plants use the low-head pumps as part of normal j 23. comedown, so there would still be a need for that, so i 24 basically we see there is no significant reduction in the f .25 low-head pumps performance for the current plants. There will ) HERITAGE REPORTING CORPORATION -- (202)628-4888 _________-A

259 1 be no benefit there as far'as we can tell, or no significant. . Slide) 2 (

(~').

U 3 MR. HIRST: Summary for the current safety injection 4 system is that the existing plants would still need to 5 maintain the high-head and the low-head capability, and the 1 6 benefits and in reliability could be realized by modifying the I. l 7 tech specs and maybe changing some of the flow rates, and what 8 was mentioned earlier, maybe relieve some of the requirements 9 on the diesel generators, on the start types, might be able to 10 delay them a little bit, give them slower start. 11 Basically this, this current safety injection 12 systems remain valid for the existing projects, and however, 13 we think we can get comparative benefits by applying advanced ( 14 LOCA modeling technology. That's the best estimate flow,.LOCA 15 space. 16 (Slide) 17 MR. HIRST: We looked at the--basically the, the i 18 large break traditionally is the design basis for containment, 19 EQ. Deletion of large break would decrease severity of ) I 20 post-LOCA temperature / pressure response, but the steam line i 21 break would still have to be analyzed. 22 MR. CARROLL: Why is that if you could use leak 23 before break on it? 4 24 MR. HIRST: Well, if you look at it, you can, you 25 are still going to need steam.line. One of the things that we '} HERITAGE REPORTING CORPORATION -- (202)628-4888

260 1 have looked at, we could, while we are--steam break would 2 still have to be analyzed to some degree. Our--we have a mass (-} %j. 3 of energy analysis that probably with the current break size 4 would give you the same benefit of leak before break on the 5 old models, so we are saying there is not a real benefit 6 there. 7 DR. SHEWMON: Different code, not as reliable 8 probably. 9 MR. CARROLL: Combustion told us that they were 10 starting to look at steam line break. 11 DR. SHEWMON: Beaver Valley did, too. Was Beaver 12 Valley a Westinghouse plant? 13-MR. HIRST: Yes, but we didn't--yes, it is a () 14 Westinghouse PWR. 15 DR. SHEWMON: Beaver Valley 2 did go through this. 16 MR. O'BRIEN: The answer is Westinghouse has not 17 attempted to apply leak before break to steam line, whereas 18 Combustion has. That's your decision. 19 MR. HIRST: Right. We see a benefit in the steam 20 line breaks. The benefits have not been quantified. I'm done I 21 with that one. Push this up, and the path and energy release 22 for the new limiting LOCA would continue, must continue until 23 equilibrium is achieved. 24 One of the things that Brian talked about Tuesday /~ 25 was that the, when you look at it, you get the short-term l (.,%/ HERITAGE REPORTING CORPORATION -- (202)628-4888

261-1 temperature is basically 300 seconds, which is established by f-( 2 steam line break. The benefit of leak before break for the EQ t 1 V 3 curves is limited, intermediate' portion of the transient, from 4 300 to 10,000 seconds. 5 Now one of the things that, that'this points up in 6 here, sort of first 300, we have done a spectrum of breaks on 7 the steam line, and at a.91 square foot break, at 100 8 seconds, we have a temperature and containment of 331 degrees, 9 okay. 10 Now for the double-ended break on the steam line, it 11 is 2.8 square feet. At 500 seconds, the temperature is 260 12 degrees, so what that says is that the small steam line breaks 13 form a temperature and in the containment actually appear to ) () 14 be more limiting on the initial spectrum. 15 DR. SHEWMON: Do sprays come on in 300 seconds in 16 these assumptions or not, containment sprays? 17 MR. HIRST: I'm not sure what the assumptions are on 18 what these numbers are. They are the spectrum we go through. 19 I assume they are using them, but I don't know that for a 20 fact. 21 DR. SHEWMON: If you have more time, your 22 containment sprays are less effective. Somehow that doesn't 23 sound right. 24 MR. HIRST: Well, the reason the difference is 25 because of entrainment, and if up got when the, if you get the fs )

/

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262 1 full double-ended break, you start pulling the water out of 2 the generators and then the, the heat is taken up in, in the 3 droplets, taken the droplets, and change them into steam. The 4 small break is really the smallest one that does not get you 5 entrainment, the droplets coming out, and that's what ends up 6 with the higher temperature inside containment. 7 So all right, so that's where we are here, and l 8 without the large break, we estimate something on the order of 9 40 degrees in a thousand seconds may result, and without the 10 large break, the time average temperature benefits of 18 11 degrees that's average over this 310,000 seconds in long-term 12 post-LOCA would still be the same. We don't see the change in 13 that. lll 14 Now we did go back and look at new plant designs. 15 (Slide) 16 MR. HIRST: The APWR, which is, a title which some 17 of you have is called SP 90. Some of you may be aware of 18 that, but it is really an evolutionary type design, but the SI 19 systems similar to existing plant configuration, has 20 high-head, low-head accumulators, has inside containment tank. 21 The high-head must be maintained for small break LOCA. 22 Accumulators are required for the intermediate break LOCAs, 23 and redesign could justify high-head elimination or 24 re-optimization, so there is some potential benefit there, 25 though we don't see it as being very large. HERITAGE REPORTING CORPORATION -- (202)628-4888

b. 263' L 1 (Slide) 2 MR. HIRST: Now the other design in 'the plant: design' fi '3 we looked at is the APc600,'which.is the advanced. passive 1 4 design. That is a passive safety injection' system which has a 5 core makeup tank which is RCS, pressure, in containment-6 refueling water storage tank, and has accumulators. 7 Key consideration'would befdepressurization:of the 8 RCS to containment atmospheric pressure, and'the in 9 containment RWST provides long term injectionLand. cooling by 10 gravity, so from that standpoint, we don't see, if we look at. 11 that.for the AP 600, small breakEis'still'aftrue1 design basis l 12-1 transient. It probable.that accumulators are-unnecessary.. We 13 would~need to consider the main steam line break, and we would' -( ) 14 have to provide extended heat removal following LOCAs.- It'is 15 still a requirement, and passive containment safeguards and EQ 16 curves are not expected to be altered based on this design. 17 (Slide). 18 MR. HIRST: In conclusion, potential benefits for 19 Westinghouse commercial PWRs, you might get some relaxation in- ] 20 tech spec for peaking factors, get increased' reliability from 1 21 the diesel start times, changing that, and you might get 22 somewhat reduced EQ envelope, but we don't think it is very 23 drastic. 24 Constraints still remain for small LOCAs. No, you 25 would not be able to eliminate any of the safety systems. J HERITAGE REPORTING CORPORATION -- (202)628-4888 ____.__________J

264 1 Still need them all. 2 New plant analysis may be needed for intermediate 3 size LOCAs. If we eliminate the big big one, then there may 4 have to be some work done for codes te develop the 1 5 intermediate size breaks. 6 And then the best estimate LOCA methodology gives us l 7 comparable events or comparable margins as to what you get for 8 leak before break. Overall plant simplification benefits do 9 not appear to be major and the EQ benefits have not been 10 quantified, but we are talking about maybe 40 degrees drop, so 11 that's where we are and that really concludes the slides I 12 have, so if there is any other questions? 13 DR. KERR: Other questions? I see none. Thank you, lh 14 Mr. Hirst. 15 DR. KERR: I note before you do the draft of the 16 letter you might want to look at that in preparation for 17 further consideration. 18 CHAIRMAN REMICK: All right. I do not recommend we 19 read the letter now. Anything further on this subject, 20 gentlemen? Okay. We are ending up a little bit early, but I 21 suggest we break for lunch, returning at one o' clock for the 22 merting with EDO. 23 MR. FRALEY: Mr. Chairman, ditring the lunch break, 24 we do have this film on the fire, on the emergency planning 2!i drill. He will be happy to show it if somebody would like. ggg HERITAGE REPORTING CORPORATION -- (202)628-4888

265 1

It is operate ~20 minutes, so why don't we make it say at ten 2

after? s 3 (Whereupon, at 11:52 a.m., the meeting was recessed, I i 4 to reconvene at 1:00 p.m. the same day.) 5 r 6 7 8 e 9 1 10 11 12 13 ,) 14 15 16 17 18 19 20 21 22 23 -) 24 25 , ^) 'u' HERITAGE REPORTING CORPORATION -- (202)628-4888

ec 266 l 1 AEI.EREOOE E E E E' l O N 1:00 p'.m. 1 L H 2 CHAIRMAN REMICK:,Let's reconvene. :This afternoon' O;n 4 l b(wc 3 .werhave.the pleasure of having!with us for one of the' periodic. 4 meetings we'have with the Executive Director of Operations, b' 5 Mr. Stello. Vic, good to have you comeLand join us. I nee; 6 you have got a number of associat'es. I assume at the proper 7 ' time you will introduce those toLus, andLwith that, I.wi11 l 8 just-suggest that you take off and-talk about the things that T o. a 9

you would like to talk about, s

10 MR. STELLO: The first thing I want to talk about4 1s j E11 1150, the ACRS letter of January 23rd. I want'to make-a 112 couple of points first. 9 / 13 After I'got the letter, I read the letter. I went () '14 back and I looked at the statement. I said you are right. We 9 15 should never have made any judgment or left the impression we i 16 ever made any judgment about what the ACRS view is or is not 4 17 with respect to the uses. 1 18 We did tell you what we intended to do, and we~ L19 should have just left it'alone. I agree with you. And I-T i i 20 apologize for anybody who read more into that than we ever l l l 21 intended. We were not trying to. sway anything either way, and 22 we've got a very, very difficult job to deal with 1150. i L 23 DR. LEWIS: That's in the past, and now we go on. 24' MR. STELLO: Now comes the hard part. That's easy. i 25' The easy part is, okay, you hadn't dealt with it. Now I am HERITAGE REPORTING CORPORATION -- (202)628-4888 J _____________________________u

l. 4 I 267 j l ) 1 asking you to. The reason I ask you to is because 1150, while , (mf 2 it probably represents some document, it also represents a %.) 3 great deal of knowledge and a great deal of information that 4 was collected over a long period of time. Clearly then the 5 question that we are faced with is what do you do with that 6 information? l 7 Do you do a PRA on a plant? Clearly it shows if 8 they fixed this widget or whatever, they can clearly improve 9 the thing, should they do it? Based on the insight they might 10 get out of such studies, if I own the plant, for my plant, I 11 think I would be inclined to do that. With that type of 12 information, I don't know that we ought to on the basis of 13 that information, however, tell them they've got to do it. () 14 There is a difference. 15 What we wanted to do today, the most important thing 16 I think, and we can talk about anything you want to talk about 17 because I have with me Tom Murley and Beckjord and John is 18 going to give the presentation, and Jim Taylor is here, my 19 deputy. Speis, I think you can probably deal with any issue 20 you would like to talk about, and there are some things I 21 think we maybe if we have time we ought to ta.k about, and I 22 talked to Ray from Baltimore about whether or not we are being 23 as sensitive to trying to get the ACRS involvement and views 24 in a timely enough way. I will tell you again, I saw some /~s 25 examples and we clearly have got to do better, so we will work U HERITAGE REPORTING CORPORATION -- (202)628-4888 J

268 1 1 on that, and I think we will solve that problem. ,e3 2 Every now and again you have to remind yourself that O 3 the Committee isn't like the staff. You aren't here every 4 day, and you are only here from time to time, and that time to 5 time happens to be once a month, and if we don't catch the 6 cycle, you are looking at a month delay in things, so we are 7 becoming I think more and more aware and sensitive to make 8 sure that the things that the Commission really in my judgment 9 ought to have the ACRS view or if the Commission itself has i 10 asked for the view of the ACRS, that we get you as much as we 11 can possibly get you, in a timely fashion. We will do that. 12 So what I would like to be able to do today, and I 13 recognize how difficult this is, talking about what are the rm () 14 kinds of things that we intend to use 1150 for in the future? 15 We are scheduled to have this' discussion along with the 16 program. 17 As you are aware, we have a peer review going to 18 start. I assume the Committee is aware of that, and if you I 19 want to know more about that, we will tell you that, but the 20 question is in the interim what do you do with the technology? I 21 What do you do with the information? And I think it would be 22 very, very helpful to the Commission to have the informed 1 I 23 judgment of the Committee itself. What does the Committee 24 think? And it isn't--again, I don't want you to think this 25 just narrow issue of 1150, but rather the whole gamut of j HERITAGE REPORTING CORPORATION -- (202)628-4888

269 ] 1 information that you have been involved with over the last 2 what is now almost nearly 15 years that has been developed. g 3 How do you go about it? That's what 1150 is really about. 1 I 4 We have a presentation that won't take too long that 5 I would suggest we have Joe Murphy go through what are those 6 intended uses. Perhaps we could talk about them, make sure we 7 have said them correctly, and if there is a problem, get it on 8 the table and try to work it out because I really think that 9 it is important that we do this as intelligently and 10 thoughtfully as we know how, and that we, both the staff and 11 the ACRS, do the best job we can to advise them about how to 12 go toward the future with this development in the technology. 13 You do remember the bruhaha--Hal, you probably lh 14 remember it better than anyone, that followed and all of the 15 misunderstandings after your report came out. At one point we 16 were even restrained. It was as though you were going to be 17 penalized if you had even read the document. I think we 18 certainly don't want to leave that kind of impression again, 19 so I think what we need to do is be very thoughtful about it. 20 What I would suggest then unless you have any 21 questions, now we just have Murphy Joe get up and take us 22 through. 23 DR. LEWIS: I agree with you. The only disclaimer 24 is that when you say read it, you remember that I held at the ggg 25 time that no one had ever read it as WASH 1400, and I still "" "^ " " -- <202>628-4888

l 270 think that :'s probably true,. but. I agree = with you. The t 1. u 2 important thing-is to decide what to do with the stuff that ^~) } 3 engenders that kind of misunderstanding. When you say to do j 4 it, thoughtfully and intelligently, thoughtfully is perhaps a 5 reasonable objective. Intelligently--we can't help that. 6 MR. STELLO: Hopefully together, all of uis together 7 have suf ficient intelligence to do the best possible job, so 8 I-- 9 CHAIRMAN REMICK: You are going to talk about 1 10 interim uses, interim plus long term? 11 MR. STELLO: No. The issue of long term, I.think we 12 have got to come back because you don't know what you are 13 going to get out of the peer review. You are guessing. If we f~)T 14 aay here is what the peer review will provide us'as a result, m 15 without that information, I think to suggest that we should 16 get beyond the gear review at this time I think would be 17 asking=too much for both of us, but the issue is how about now 18 for the interim? 19 DR. LEWIS: In fact, you put it very well, because i 20 it is really not a matter of just that. It is all the 21 accumulated wisdom of these 15 years that they have put 22 together, and even if it turns out that 1150 does an imperfect 23 job of encapsulating that, we still have the problem of what 24 to do with the accumulated wisdom. 25 MR. STELLO: Right. We talk about liner O, 4 HERITAGE REPORTING CORPORATION -- (202)628-4888

271-1 melt-through on a BWR, so shall we stop talking about it?- 2-That's part of 1150. That's the kind of thing I think that ,f,.g (/ 3' frightens me, that there is very important safety information 4 unless we articulate very carefully that there is that body of 5 knowledge that we ought to go move on with--without any 6 further discussion, I would suggest'that we have Joe go 7 through. 8 DR. KERR: I guess Joe is going to tell us what he-9 is going to talk about. When you refer to 1150, are you 10 referring to draft 1150 plus supporting documentation, or some 11 later document, or is he going to tell us this? 12 MR. STELLO: He will tell you that, but what I mean 13 is the entire accumulation of that knowledge which would be () 14 however many attachments or appendices, volumes will be. 15 attached to 1150. i l 16 Joe? 17 MR. MURPHY: 1150 itself will be two volumes, but in 18 terms of all the contractor reports that go with it, it will 19 be over 20. 20 MR. STELLO: I mean all of it. 21 DR. KERR: Now is there a later draft than the draft 22 that we reviewed earlier? l 23 MR. STELLO: I have promised that there will be 24 another draft available on April 15th at 7:30 in the l r^3 25 morning--on the 17th. (J l HERITAGE REPORTING CORPORATION -- (202)628-4888

2721 1 DR. LEWIS: We are all going to be busy on April 2-15th. (n) v 3 CHAIRMAN REMICK: Seventeenth. 4 DR. SIESS: I think this is general-enough to bring 5 it_up here. 6 What to do with the information of 1150, it'seems to 7 me the first thing that if I were a plant owner, first thing I 8 would want to do is to be sure it is correct information, and 9 to be sure it is applicable to my plant. I would want to say 10 suppose I had done something in the light of what I knew about i 11 the first 1150. Would it still have been.the right thing to 12 do now with the revised 1150? 13 MR. STELLO: That is exactly the way I would go /~'s ( j 14 about it. 15 DR. SIESS: And as far as one of the main lessons I 16 see out of 1150 is that most of these things are 17 plant-specific, not just the bottom line,- but the dominant 18 contributors, the specific vulnerabilities, and if I have a 19 plant, I would be very careful using 1150 because I would want 20 to be sure that there wasn't some gimmick in there that made l 21 it not applicable to my plant. 22 MR. STELLO: I think we are getting a little bit 23 into what Joe will do, but we have, I was told that the ACRS 24 definitely has a copy of this paper. It is SECY 8905A. r~s 25 CHAIRMAN REMICK: Yes. (-) v L {_-_----------_-----_-_-- nERI m E R m R m o Re RA m N -- (202)628-4888

273 1 MR. STELLO: That we are here to talk about, but let (~~) 2 me give you an example to illustrate the very point you are 3 making. 4 If I were looking at design results, which were 5 discussed in here, you clearly have a question about seal, 6 behavior of the seals they have, and the component cooling 7 water system. It shows that is a dominant contributor. For 8 the reasons that are clear, they have a cross-connection, and i 9 they have the seals. 10 Now would I use that information if I opened the l 11 plant and be making any judgments--I can't speak for the 12 owner, but if I did, it is clear to me that no matter what 13 else happens, I still have these problems, and these problems () 14 are not trivial. They are important, and I would be looking 15 at things that I can do. The next seals I would order.I would 16 be looking at an improved seal and they indeed are and I would 17 be putting them in because they now tell me based on this kind 18 of information, they are far more important than I maybe 19 thought they were. 20 DR. SIESS: That was the easy one, though. Take a 21 MARK I and compare it with Peach Bottom. 22 MR. STELLO: I am not suggesting that you can do 23 that, but if I own a typical MARK I, I would look at the 24 lessons that came out of Peach Bottom, and a bunch of other 25 PRAs, which is another program that we have. (} HERITAGE REPORTING CORPORATION -- (202)628-4888 l u_______-------_

77 T7g ~h l o -274 L 1 DR'. SIESS:. Ten to'the-minus 6 core melt: 1 2 . probability. 1 1

3:

MR. STELLOi I don't think~I care what the' bottom i i 1 If I have 1 4. .line number is. That's not'the11esson I learned. 3 5-to use the bottom-line numberLas a--I don't think'any-ofLus .j i .6 believe that bottom line numbers tell.you very much-anyway. 7-It is the information.that.you get out of the' process itself l .8 that is very important, but: the lessons that ' you get out ' of it 9 .that are very.important, they are in here. 11 0 . Joe, why don't you start? 11 MR. MURPHY: The firJt thing I found out was"my 12 secretary has some slides that I wasn't using in the package 13 and some that I am using are not in the package, so I think we. () 14 are going lto need to get-that straightened up and get them ( 15 down later. 16 MR. STELLO: Then we will leave what you use'andl '17 they can make the copies after the briefing. 18 MR. MURPHY: I think the first!two vugraphs I have 19 we have pretty well covered. It was just sort of a reminder 20 of what 1150-is and isn't. 21 (Slide) 22 MR. MURPHY: It's a snapshot of the risk at a 23 specific point in time. It is an estimate of the risk, and it 24 suffers from the obvious problems that all risk analyses do 25 with the current state of the art in terms of how they 1 HERITAGE REPORTING CORPORATION -- (202)628-4888

275 1 represent human errers, and how the safety culture of the 2 operating staff is reflected, lack of data and uncertainty in 3 some of the external phenomena, but more importantly is that 4 it is a resource document. It is a resource that gives us 5 information on important sequences of phenomena, and this is 6 used as a trigger for how you go forward. 7 I don't think anybody would use the information 8 coming out of 1150 uncritically but the fact that, that 1150 9 identifies some as, something as being potentially important 10 at a given plant suggests that it is worth further 11 consideration to see whether there is a problem or not, what 12 it isn't, and I think we have already said that, too, it is 13 not the sole basis for making either plant-specific or generic () 14 decisions. I wouldn't make a plant-specific decision on one 15 of those five plants solely on the basis of 1150. You have to 16 go back as you said to the operators, to the utility that owns 17 it, and make sure that we represent the plant that exists 18 today. 19 The plants that we have analyzed, the freeze date 20 for the analysis was roughly a year ago. There is a lot of 21 changes that have been happening, a lot of changes between the 22 draft and the final, and a number of those changes come from 23 the fact that we identify what I will call vulnerabilities in 24 the draft report without great regard to the probabalistic 25 involved. The utility looked at them, saw their plant didn't HERITAGE REPORTING CORPORATION -- (202)628-4888

276 1 operate in the way they thought.it did, and they changed the (~T 2 plant, so some of them, the major changes in the core melt LJ 3 frequency analysis came from the plant, the fact that the 4 plant has changed between' draft and final. 5 It has probably changed also in the last year, we 6 also have,.so again you wouldn't use these uncritically. The 7 people that are doing IPEs on these plants will have a nice 8 basis to start from, but they will have to do more work and 9 they will have to identify that. In fact, this represents the 10 plants that are out there. Then obviously it is not an 11 estimate of the risk of all the nuclear power plants. It is. 12 an estimate of the risk of the five we have got. 13 (Slide) O(, 14 MR. MURPHY: And only those five; the-- 15 DR. LEWIS: Why do you say that, Joe? Because the 16 WASH 100.was an estimate of the risk of two nuclear power 17 plants and yet provisions were drawn about the population. 18 MR. MURPHY: I don't want to draw conclusions about 19 the population of all plants when we have only looked at fie 1 20 of them. 21 DR. LEWIS: No conclusion at all? 22 CHAIRMAN REMICK: Would you use your mike? Excuse l l 23 me, Ha1. I l 24 DR. LEWIS: I'm sorry. You know, this is a point l 25 that has come up before and it is probably worth spending one l (~)T u 1 i HERITAGE REPORTING CORPORATION -- (202)628-4888 i

I l-277 .1 momen t - on '.. i. 2 .When you sample a population,;whether'it is.two or. 3 five-times,.you do learn something about the,.aboutithe rest' 4 of the population. Obviously you can't,'to.use'your word, 5-carry-the results over uncritically. Nobody does, ever admits N. 6 to.doing'anything uncritically anyway, but still you'know, all ~ 7 those' statistics is based on being'able to take a sample.of a 8 " population, and infer things about the population from it,.and-1 ? you are just going to give up that potential? 9 10 MR. MURPHY: .No, no. I wouldn't give--you.have that: l 11 potential, but I don't know how to quantify it, either. 1 12 Obviouslyfif.I-have found at least five plants were.all very 13 high core ~ damage frequency, I would be concerned about'the '( ); 14 population of plants in general as-well. These give me a 15 better feeling, the fact that the' core damage frequency is 16 reasonably low on.these plants. It indicates to me that the 17 regulatory process works, and it is one'of the reasons why it 18 is low, but I don't wa;nt.to make a concrete statement that 19 therefore I believe that all the plants were ever, this level 20 of safety is represented by all the level of plants until1I 21 have done more analysis. We do have a large compendium of PRA 22 information. 23 MR. STELLO: Joe, let me interrupt, but isn't it 24 fair that some of the things that we have learned, and if you 25 look at--let me pick the two BWRs, for example, that there are HERITAGE REPORTING CORPORATION -- (202)628-4888

c__-_____- 278 1 fairly easy things that can be done that will significantly 2 reduce risk, and those are generic lessons, and in that ,-q N) 3 context:I think there is generic information that's helpful 4 and useful, and while you might not want to say these five. 5 numbers can be used to predict core melt frequency, I think 6 they at least show you what is possible, what can be done. 7 These are the most studied plants. A lot of changes, very 8 simple changes have been made, but it also tells you you can 9 do the same thing, and that's precisely I think--I agree with 10 you that there is a lot of insights that are in fact 11 applicable to the whole family of reactors. 12 Go ahead. Go on. 13 MR. MURPHY: Well, in that vein, I think it is the (~) 14 fact these are five more PRAs to add to the 30 plus-that are As 15 already in existence, and looking at all the insights, the 1 1 16 problems that have been found in the various, all these 30 17 plus PRAs, we have a fairly good idea what to look for in ] ) 18 terms of things that have the potential for biting us, and to j 19 that extent, I have a warm feeling. f 20 In terms of our intended use, it has already been 21 used in the process of preparing the documentation for what an 22 IPE is and how to go forward with an IPE. 23 It will also serve as a framework for how we 24 consider accident management approaches. Again, it is 25 information on five plants, but that information gives us some 7sO HERITAGE REPORTING CORPORATION -- (202)628-4888

[l 4 r. '279 s L 1: . ideas as to.how we can go forward. Itzhas been, input to the 2- - containment:performancefimprovement' considerations have 3 .already.been discussed with the' contractor on MARKHI and it 4 - will'be.on the later plants. 5' Again, we have.a very comprehensive set of entries- '6 and analyses, and those analyses are. event trees for the 7 process. L' 8-As I mentioned earlier, on the accident. frequency-9 end, I see it as evolutionary. It is not revolutionary, fit 1 i 10 adds to the compendium of more than 30 PRAs that are already. c 11 - in existence', some of which are available to the staff)and 12 Esome of'which are not. 13 It gives us that means to assist in identifying () 14 those designs features or practices-that can have an adverse 1 15 impact on safety, and it just adds'to that. library of-16 information coming out of all the PRAs that have been done to- ~ 17 date. 18 (Slida) l 19 MR. MURPHY: We see it'as a possible testbed for'the' 20 evaluation of alternate safety goal implementation strategies.. 21 We now-have the models in existence or will have within the 22 next two weeks or so that we can take various definitions of 23 safety goals. 24. One that has been controversial is the definition of l 25 a large release. We can try several definitions and see how } 1 HERITAGE REPORTING CORPORATION -- (202)628-4888 l 9

280 1 .they apply to the various plants..Our models:will-allow us to ~ l 2 .do that. ] 7-) A.) 3 .Then:it is one' element in the evaluat' ion of research-. ~ ~ ) b 4 ~ priorities-and potential tool to 'use as one element-in generic ] 5 issue resolution. Again, here it is not the bottom lineJIn J .6 the NUREG 1150'so much. I think in looking at the.research 7 prioritization, you wouldn't want to do_something so simple ~asi 8 to take.a' rank regression analysis of the 1150 results, see 9 .what is contributing most to.the uncertainties, and say myJjob 10 is done. It is more difficult than that. You would have'to 11 go:and look at are there any clips if you'will, are there.any;, sharp 'ropoffs? Small changes in assumptionLean cause great d 12 11 3 differences, and look atLit'in that light as well. l I ) 14 The input information coming from.the 1150 is what I 15 see as the important things now. Vic mentioned-the reactor 16 coolant pump seal.on the Zion job. This does.not imply to me-17, that Zion has a problem with.the reactor coolant pump seals. 18 There are potential extenuating circumstances to the plant 19 .that we would have to look at. 20 What it does suggest, that under certain 21 circumstances, the seal LOCA can be important, and we know 22 under what circumstances those are, and we--and this is a 23 combination of what, the properties of the seal and the 24 properties of some of the support systems of the plant. We 25 know what to look at, look for to see if a similar situation ( h HftITAGE REPORTING CORPORATION -- (202)628-4888 L_

i 281 L1-could existIin another plant. 2 The MARK I. liner attack problem was identified in ,i .si 3 the NUREG 1150, l[ think'we would.be remiss if we forgotswe p Y 4 knew about this during the peer review process.- j 5 Information at that level, the information.that.was' q i 6 derived while we were studying the problem'is the information 7 ,I think'that we can't lose while de are going through.the peer l 8 review process, but that doesn't mean that we use.it 9 uncritically,'and it's more in the framework where a potential l I 10' problem may be treated in the same way an allegation would be. 11. It triggers-further attention of the staff rath'er than' 12 suggesting necessarily a solution to the problem. 13 (Slide) 'A sm) 14 MR. MURPHY: What we want to do is utilize the 15 information data base that we developed as the. study has gone-16 on. For instance, we have over a half a million dollars worth 17 of code runs with MELCOR, MELPROG and CONTAIN that support the-0 18 NUREG 1150 effort. These will be published in the supporting 19 document s for 1150. We ought to be able to make use of this + 20 information as we progress with the peer review of 1150 21 itself. 22 We have gained the assorted understandings from the 23 evaluation of expert opinions, and this has even been true 24 where we have had bimodal distributions in the expert opinions I 25 as we did in the case where on the liner melt-through. We ] {} HERITAGE REPORTING CORPORATION -- (202)628-4888 j

) 282 1 have learned some valuable information. We have learned that l 2 we have had, in this case we have six experts and they are l 9 l 3 almost equally divided on how they see the results of the, the 4 question of liner attack. 5 Now the fact that three feel one way and three feel 6 the other is relatively unimportant, but what is important is 7 we have three bona fide experts, six bona fide experts that 8 feel differently. We have the basis for their opinions. So 9 this gives us not only their opinions, but the base for their 10 opinions, and that let's us go further then in understanding 11 the problem. That's the type information that we don't want 12 to lose during the peer review process. 13 DR. CATTON: How do you go further in understanding llh 14 the problem? 15 MR. MURPHY: I can use that as the base. In other 16 words, as I start a research program to explore this further, 17 or I don't say I, I now have the opinion of six experts that 18 is documented as to how they feel about it. I don't say but 19 this is part of 1150 peer review so you don't touch the 20 opinion of these six experts. It gives me a base to go 21 forward on. 22 DR. CATTON: Somehow I don't hear words like gee, 23 this means we had better run some kind of sample experiment or 24 something, 25 MR. MURPHY: It may well be that you come to that g HERITAGE REPORTING CORPORATION -- (202)628-4888

, - - - - - = - _ _ _ _. '283 1 -conclusion. Looking at the six experts, as to where they are (} 2 coming from, you may well be able to look at those and'see v 3 that there is one key portion of the phenomena that is driving 4 one group to go one way and one group the other and it would 5 then suggest what kind of an experiment you would go forth 6 -with. 7 DR. CATTON: Maybe you need another group of 8 experts. 9 MR. MURPHY: That's possible, too, but I think for .10 the next group of experts, you still would want to have the 11 input from the last group. I mean they have done 12 calculations. They have done a lot of analysis. It would be 13 wrong not to use that information as you wing forward. () 14 DR. CATTON: I have heard a lot of, and I have 15 listened to some of the experts. 16 MR. MURPHY: All I am saying, this is an issue it is 1 17 hard to say where does 1150 stop? It was identified as part 18 of 1150. It has been discussed in a lot of different forms i 19 since then. But where does 1150 stop? Where do you say you 20 won't use the--if you don't use the results from 1150, where 21 do you terminate this activity? You know, where do you 22 essentially say this information from 1150 is embargoed and 23 don't use it in your decision-making process? It would be 24 very difficult to do right now because it is hard to say what (Q 25 came from 1150 and what didn't because it is part of the U HERITAGE REPORTING CORPORATION -- (202)628-4888

284 1 technical background that all the experts are using, 2 DR. SIESS: I don't get what, what your concern is ,.s ) 'ud 3 here. You don't know whether they use knowledge because it 4 doesn't come under the rubrick of 11507 5 MR. MURPHY: No. What I am saying, Dr. Seiss, is 6 that we started off and this problem was identified as part of 7 the 1150 analyses and 1150 deemed it some more analysis and 8 then we called together the panel of experts and they did some 9 more analyses and they reached their conclusions. 10 Now many of these same experts also were involved in 11 the containment performance improvement workshops, for 12 instance, that were held last year, and the information they 13 used at their workshops, they presented at those workshops, /'N 14 were basically the analyses they did in support of NUREG 1150. (J 15 Where does 1150 stop and containment performance improvement 16 begin? You know, you jtst can't do that. These analyses 17 exist and you take them for what they are worth and you pass 18 them on as you go forward in the technical analysis of the 19 issue. 20 DR. SIESS: You said knowledge was more than 1150. l 21 That was a point that you made. Now the difference between l 22 that knowledge and 1150, the only difference I see is 1150 has 23 been peer reviewed and the other hasn't. 24 MR. MURPHY: Well, I am talking more in terms of the l 25 current draft 1150 that is about to come out, the supporting f3 .O HERITAGE REPORTING CORPORATION -- (202)628-4888

285 1 information for it. That information was frozen. To do our 7x 2 analysis we froze the technical input as of about a year ago, b 3 march of last year, so any analyses that have been done since 4 then aren't reflected in 1150.because from the time we freeze 5 the analysis to we get the results out, it takes roughly a 6 year. 7 DR. SIESS: Is freezing-the analysis the same as 8 freezing knowledge? 9 MR. MURPHY: It is essentially the same as freezing I 10 the knowledge of important phenomena and the plant designs ~so 11 you can go forward and do the risk analysis. 12' CHAIRMAN REMICK: Joe, am I correct that your 13 underlying concern here is that somebody might say embargo the .g~) 14 use of 1150 until it is completely peer reviewed, and what you q_ 15 are saying is I don't know what you mean when you say embargo l 16 1150? '17 MR. MURPHY: That's part of it. If you are saying 18 embargo the bottom line numbers of NUREG'1150, it doesn't 19 bother me at all because I think it is a mistake to use them 20 at this stage, but if you are saying embargo a half a million I 21 dollars worth of code runs, severe accident codes, that really 22 provide the basis for an awful lot of our knowledge of severe 23 accident, then that gives me a real problem because this is a 24 basic information that we have that I would hate to ignore for 25 the next year or so while we are undergoing a peer review. ~ ) l l HERITAGE REPORTING CORPORATION -- (202)628-4888

286 l' DR. SIESS: You have go a' lot more~ confidence in.all 2 those code runs than you have in the-bottom line for'1150?? .O 3- 'MR. MURPHY: 'I don't'liave--it depen'ds on what~.you 4-mean by confidence. I don't have' great' confidence in:the N 51 actual numbers' coming out'of it, but I think they~have given 6 us an' awful: lot of valuable insights. I am not going to. 7 quibble as to the second significance. figure:on'many things 8 that they predict, but by the same' token, we have knowledge of ' 9 how these calculations predicts how severe accidents proceed' E 10 that we didn't have before. I think it would be a mistake for 11 us to ignore that information. It doesn't mean we don't look 12 at it critically knowing the. weaknesses.in the codes. 13 DR. SIESS:.. Carefully qualified statement--you have ) ). 14 knowledge on how these calculations predict the severe 15 accident proceedings as distinct from knowledge of how a L. 16 severe accident proceeds, is.that right? l I 17 MR. MURPHY: If I understood what you just said-- l 18 DR. SIESS: You just said it. I didn't..You said 19 we have knowledge of how the calculations predict a severe 20 accident will proceed. 21 MR. MURPHY: That is correct. 22 DR. SIESS: Now is that the same thing as having 23 knowledge how a severe accident will proceed? 24 MR. MURPHY: No. No. We know in some cases that I 25 there are deficiencies in these codes, and we have some idea j O ) l f HERITAGE REPORTING CORPORATION -- (202)628-4888 J

i t 4 287 1 as to how these deficiencies will drive things, i r~j 2 DR. SIESS: Can they predict how TMI proceeded? (._/ 3 MR. MURPHY: They are getting better along that 4 .line, but no, I won't say they can do it directly. 4 5 CHAIRMAN REMICK: Proceed, Joe. Excuse me, Ha1. 1 6 Did you have a question? 7 DR. LEWIS: No. 8 CHAIRMAN REMICK: Go ahead, Joe, 9 (Slide) I 10 MR. MURPHY: This is the points similar to the one I 11 made on the Zion pump seal. Where we find items of risk 12 significant ia these analysis, it may warrant further analysis l 13 or regulatory attention now rather than waiting until the' peer A, lu,) 14 review was over. Again, that doesn't mean we use the results 15 alone. It could just mean it triggers a further analysis by 16 the staff, and Tom Williams.used the phrase a while back that 17 it was essentially the same as an allegation that required 18 further investigation. 19 DR. KERR: Joe, you and Vic have both said, and I 20 agree with you, that one has to be careful how one uses the 21 bottom line, and yet you talk about items found risk 22 significant, and risk significant presumably means that the 23 bottom line is bigger than you would like, l 24 MR. MURPHY: No, I don't mean that in that phrase. /"'s 25 When I use the term risk significant, I mean I have done the U i HERITAGE REPORTING CORPORATION -- (202)628-4888

288: 1-calculation offrisk,'and these are.the-dominantLeontributors 2 -to'the number.that:I get. That number may.or.'may not.be' .3-acceptable, but these are the dominant contributors to that. 4 risk-Something has to be a principal contributor even if the 5-risk is very low. 6 DR. KERR: Oh, so you-don't really care what the' 7 risk is? You just want to look for a dominant contributor to 8 whatever it is? 9 MR. MURPHY: I care what it is, too..What'I am 10 saying.is when I'look and'I find what is significant, what is: l 11 driving the risk of this plant, it then raises,.the question 12 in my mind is along several lines. I compare that-kind.of a 13-result tx) the safety goals'and say am I'well within them or-p ( )- 14 well outside of them or how does that affect it? I.look at it. 15' in a different light and I say is the plant operating-the way' 16 'I' thought it would operate? Have I found that, the dependency. 17 that I didn't'know it existed? Is it something that','.have you' t. 18 found essentially a gap in a regulatory fabric because-I have .19 a dependency that I thought I was protected against and I 20 wasn't that I need to go fill? 21 DR. KERR: Now there are two additional steps that 22 I'm sure concern you, and certainly-concern us, and that is if 23 you decide to do something, then you need to be sure No. 1, 24 that it reduces risk, and No. 2, that in the process of 25 reducing, potentially because you fixed that one thing, you } HERITAGE REPORTING CORPORATION -- (202)628-4888 i

289 1 have got increased risk because of something else, some 2 interaction or something, so those two are fairly significant gg (I 3 considerations in how you use, if I understand the terminology l 4 being used, how you use 1150 or how you use any sort of 5 knowledge in the risk reduction process. 6 I mean it isn't I think just what 1150 or any other 7 knowledge tells you, but how you use it and how you use it 8 means I presume you are trying to reduce risk. If you pick a 9 particular contributor, you have to be sure that whatever it 10 is you decide to do indeed reduces that, and secondly, that.it 11 doesn't somehow make something else worse. 12 MR. MURPHY: I agree completely. 1 13 MR. STELLO: And I might add the best way to go ('.) 14 about that, if it doesn't really make any difference in the 15 bottom number, then I want to come back to does it really make 16 a difference? If you have something that suggests in a 17 relative scale this particular sequence is important, then you 18 look at it. If in fact you want to do anything about it, I 19 think, if I understood your point, is don't do that without 20 going back and taking a look at the big picture because you 21 could have made it worse. I couldn't agree with you more, but 22 I think the point of it is that bottom line or is risk itself 23 a significant issue? If it isn't, then why are we doing the 24 safety goal and everything else? I think-- 25 DR. KERR: This I think it seems to me, Vic--well, ( HERITAGE REPORTING CORPORATION -- (202)628-4888 )

290 1 I'm sorry I interrupted you. Go ahead. 2 MR. STELLO: I think the whole activity some day 3 would like to get to--we have been through the safety goal 4 issue now for almost eight, nine years, but the whole concept 5 when do you say this is enough and in fact even in the case E 6 that we are talking about, but let me assume that Zion would 7 meet everything that we had even forecast for the safety goal, 8 then the question is after we see the final numbers, do you 9 really need to do any more? Is any more really justified? 10 Well, that's for two of us to decide--the owner as 11 well as the regulator, and how we would go about deciding I 12 think comes back to this relative importance of any particular 13 sequence to make sure you are working on what is important, () 14 and I know of no better way today for us to answer that 15 question except through the insight you get from PRA. I know 16 of nothing that is available to deal with that question better 17 than what we get out of this methodology. 18 DR. KERR: The point I was trying to make, probably 19 wasn't making it very well, is that I think to me it is a 20 mistake to say you don't pay any attention to the bottom line l 21 just as it is a mistake to say you pay all attention to the l l 22 bottom line. 23 I can't avoid paying some attention to the bottom 24 line, and the difficulty I think is chosing between how much 25 attention you pay to that, and how much attention you pay to a (} HERITAGE REPORTING CORPORATION -- (202)628-4888

i ~291 1 . dominant contributor or whatever it is that:onefidentifies. ~ 2 2 This is part of the' thing that.to me at least makes a problem. W) ( 3 interesting-and somewhatfdifficult. -4 MR..STELLO: I agree lwith you.. When 'we are all done: n 5 and 1150 is peer reviewed and.everythingLis all finished, weL 6 are finished.with.it, it willLgo'into the bin with a. pool

7 aboutLwhat we know about all'other PRAs and those plants that-8.

we ought to work on. 9 .I hope one of the things,we will pay attention to is 10 .in deciding answers to questions like that is if theychave~a 11 . peer review, where is the bottom line?' It.is certainly in the 12 ten to the'minus 5 and ten to the minus 6.- There are others 13 down at couple or three or five or eight times ten to the () 14 minus 4. I think I would be remiss if I didn't put those on 15 at the beginning of.the list of things to lookLat rather than ~ 16 worry about the other plants. So.I think, I think you.are i 17

right, i

18 I think you make a. point, and I agree'with you, but-19 with respect to should we do that now with 1150, I think until. l t 20-the peer review is finished, I think that would be a mistake. 21 I think not only does it need to be just on the peer reviewed, 22 but on every one of the utilities that own these plants we. .l 23 ought to hear from them one more time after this report is 24 finished, and until all that is done, I think we clearly ought i 25 to stay away from attempting to come to the bottom line on it, { HERITAGE REPORTING CORPORATION -- (202)628-4888

292 1 but later when we are finished, I think you made a point, and 2 I agree with you. 3 DR. LEWIS: This has been a good conversation, but 4 the bottom line also applies to the contributors. That is, 5 each contributor has its own bottom line, and it is not, and I E 6 agree with what Bill was trying to say, that it is not a 7 matter of being absolute about either the bottom line or you 8 don't obey the bottom or ignore the bottom line completely. 9 That's why I am always turned off when people say to me we are 10 not going to depend on this as the sole basis for regulation. 11 That's an empty comment, of' course, because history is not, 12 you are not going to depend on my opinion as the sole basis 13 for that. I'm sure of that, so the issue is to use your () 14 judgment and your wisdom and in particular, in looking at risk 15 significant contributors, one shouldn't ignore them until the 16 peer review is in, nor should one take them seriously until 17 the peer review is in. One should do something in between. l 18 Among these so-called risk significant, you don't know that 19 they are risk significant; just know that this draft shows 20 that they are risk significant. 21 MR. STELLO: In the relative way they are. 22 DR. LEWIS: Right. So what you are going to do if 23 you are a wise person, which you are, you are going to look at 24 each of these things individually and you are going to say is 25 this one of the most criticized parts of the first draft or is HERITAGE REPORTING CORPORATION -- (202)628-4888

i 293 1 this one of the least criticized parts of the first draft? If' .f g 2 it is one of the most criticized parts of the first draft, it ) \\-) 3 may look'like it is risk significant, but you are called upon V 4 to take any action on it. If it is something that you would' 5 still--the f,irst draft, through peer review of the first 6 draft, then yes, that it makes a lot of sense, j s 7 MR. STELLO: I can only say, Hal, if the Co'mmittee I 8-could find some wise way to suggest how to do that, provide us 9 with that advice, it would be enormously helpful. 10 DR. LEWIS: But that's why we pay you so 11 magnificently! 12 DR. SHEWMON: Let's go on. 13 MR. MURPHY: I think we basically have said it all. f .r~ (_) 14 Again, the kind of insights I am talking about here, as we 15 have noticed, for instance, that inter-ties, crossover points 16 between trains, between plants at multi-unit sites can be 17 extremely important in reducing the core damage frequency, and 18 we have found that on a couple of plants that we have analyzed 19 a well-engineered crossover can be very, very good. We 20 haven't found the problem on the plant we have analyzed, but 21 it is also obvious as we look at the analysis we had that a 22 poorly engineered crossover can really cause a mess, and can l 23 defeat the redundancy that you have in the project, so it's a l' 24 double message. A well-engineered one can buy you a lot and a s l 25 poorly engineered one can cause a lot of trouble. i HERITAGE REPORTING CORPORATION -- (202)628-4888

3 294 1 There is a few pages worth of that type,of insight-(~'T s2 in the Commission paper, and these are-the kind'of things that U/ 3 I.was talking about in this bullet. Again, anything we do 4 with the report has to recognize.that we have peer review in 5 process. 6 DR. KERR: It surely would have been astounding if 7 the review process hadn't done that it would seem to me. 8 MR.. MURPHY: I'm sorry. I didn't hear you. 9 DR. KERR: It would be astounding if the process had 10 . revealed that a well-engineered system can prevent something 11 and a poorly engineered one can cause trouble. l 12 MR. MURPHY: Oh, I agree. One of the problems with 13 insights to come out of PRA, to be quite honest with you, as ./ 3 (_)- 14 you sit and you are working, you come out with these insights, 15 do the analyses and a number of things come out. And a good 16 engineer will look at them and say well, gee, I knew that all I 17 the time. I knew AC power systems were important. I knew I 18 had to worry about the depletion of batteries in the long 19 term. 20 I don't really have a good answer to that. What 21 this is is a, a logical way of working through the 22 interactions of systems at a plant, and to come up with 23 conclusion of what is important and what isn't. A good 24 engineer should recognize most of these things, but in many (a~} 25 cases they haven't, and the integral process has been helpful i HERITAGE REPORTING CORPORATION -- (202)628-4888 L_-

1 1 295 J l 1 in putting the list together. 2 DR. KERR: If you are looking for ways in which you . - ~. .( 3 might use these insights, then you really take this seriously, 4 my impression of staff positions developed over the years is l 5 that inter-ties have been discouraged. 6 MR. MURPHY: That is correct. '7 ' DR. KERR: Of possible common mode failures; if you 8 now have discovered something that seems to indicate that.that 9 is not only not true, but perhaps the opposite of what PRAs 10 reveal, I would move to start change those regulations. 11 MR. MURPHY: I think-- 12 DR. KERR: If you are convinced that's so. 13 MR. MURPHY: It is clear to me that on the older f~) 14 plants which is basically what we have analyzed, the underties a 15 have been very, very helpful to us. They have been worth--I 16 hate to put a number on them, but a factor of three or more, 17 in core damage frequency. They have been significant. 18 MR. STELLO: I think Mr. Kerr hs a very, very valid 19 point. It is the very kind of thing we are talking about. As 20 you get these insights, and we start to really believe them, 21 we ought to go back and examine the regulations, which is one ) 22 of the things that we have learned a long time ago, and we 23 really ought to get serious about it. I agree with you. 24 There is one thought I had when you made that 25 comment you did a moment ago, Ha1. I want to just underscore 1 i l HERITAGE REPORTING CORPORATION -- (202)628-4888 m ___ _ ___ _ _ _ _.____ _ ____ ____ _J

] 296 l 1 how important it is. ry 2 I remember when we were talking about shutting Peach %J 3 Bottom down. Peach Bottom has continued to be the plant in. 4 terms of bottom line numbers that has continued to produce the 5 lowest core melt frequency. I did not hesitate for a moment 6 to that. They had to be ; hut down because of the way they i 7 were operating a* th p3 ant, so the way you operate a plant, 8 no matter what tT bcttom line number, no matter who gets PRA,- l 9 you surely--it nE ar will encompass the sole basis for doing 10 anything by definition, and I couldn't think of a more 11 dramatic example than what came to my mind while you were 12 saying that. Management is critical. i 13 DR. LEWIS: You can't expect me to disagree with you i i '( ) 14 on that. 15 MR. STELLO: Well, I knew you wouldn't. 16 CHAIRMAN REMICK: Joe, before you run away, would 17 you put up there again, there were five proposed uses--I am 18 not sure if the Committee appreciates that basically if they 19 are able to--we are being asked to make some comment on 20 proposed uses. 21 Are these the only proposed uses that you want to-- 22 MR. STELLO: No. If the Committee can think of some 23 other, and Hal mentioned perhaps there is a way to try to deal 24 from the perspective of bottom line numbers, so maybe we are r" 25 being supercautious, and that might be wrong, and if there is (_% / l HERITAGE REPORTING CORPORATION -- (202)628-4888

297 1 some way to deal with that issue and'the Committee can invite, 2 suggest further use, I think I would strongly urge the 3 Committee to do that because I think that would be extremely 4 helpful to the Committee and to us. 5 And finally, to the Commission we are going to make 6 that policy call. If they are, if you can think of some other 7 things to add to that, I didn't want to suggest you ought to 8 limit it to that. We view them as important. 9 MR. MURPHY: These uses you have seen before. They 10 are verbatim what was in the integration plan, and also I 11 discussed intended uses with the Committee before on NUREG 12 1150. The words are out of the integration plan, and they are 13 the five uses that we talked about, that are talked about in () 14 that. This is the framework that is, reiterate it is the 15 framework for IPEs, the input to the containment performance 16 improvement, the compendium of PRA information on accident 17-frequency, and the contributors thereto. The testbed for 18 evaluation of the safety goals and one element that helps us 19 in the prioritization of research, and again, the information 20 data base that allows us to have the tool, that is one element 21 in generic issue resolution. 22 CHAIRMAN REMICK: I see the staff is asking us if we 23 can address the uses. 24 How would you see--I believe that falls within your 4 f 25 subcommittee--how we would proceed on doing that. ) m HERITAGE REPORTING CORPORATION -- (202)628-4888

298 1 DR. KERR: I would-like to have a little more r~3 2 specific set of questions. I think we would go-over it in the ] (/ L 3 subcommittee, would bring it to the Full Committee. It is a l 4 worthwhile endeavor from my point of view. 5 CHAIRMAN REMICK: Would you see that you need to 6 wait for the next version of--when is itt April? 7 MR. STELLO: April 17th. 8 CHAIRMAN REMICK: Seventeenth? 9 DR. KERR: Since April 17th is not far off, if it is 10 going to be available by then, it,seems_to me to make some 11 sense to do it since 1150 now encompasses somewhat more than I 12 had anticipated before I heard this conversation. I don't 13, know what incremental edition will be, but-- (., (_) 14 MR. STELLO: I would at least--I know I'm suggesting 15 something that really departs from the practices, but if there 16 was a way, at least if it were possible to give some general 17 comment or observation, I believe that the Commission meeting 18 is now scheduled for us to discuss this with them on the 16th 19 and 17th of March, the committee perhaps could say something 20 in this meeting because if you don't., and you wait until April 21 17th, then we cannot have any discussion until May, and 22 hopefully, at least I pray that by that time, we can have the 23 peer review at least starting. 24 DR. LEWIS: Now I wonder-- ('T 25 DR. KERR: Certainly--excuse me. Certainly we have V HERITAGE REPORTING CORPORATION -- (202)628-4888

w a 299; i 1 improved the peer reviewfso we don't1have to comment on that' } 2-' 'further. 3 MR. STELLO: 'I understood 1that. I'm talking about-4 the' interim use' remember is.the thing that you wanted to be 5 able to do between the time the peer review starts and it is 6 over.. 7 DR. KERR: Okay. i 8 MR..STELLO: And-we would at least be into it, so at-9 least suggest to the Commission,-you know,'what we are. going 10 to say because we told them in the paper, we tell them we' 11 hoped they would have some additional commentLfrom the 12 Committee. -13: Int. KERR : Vic, I.want to give the Commission, I -(g,/- 14 personally would want to give the Commission a soundly base'd 15-set of recommendations rather than a hurried one,.and-I think 16 that's what you would want, too, so we do need to discuss 17 that. 18 MR. STELLO: I am willing to take both. 19 DR. LEWIS: Well, I just wonder, I think that when 20 we started this conversation, we were talking about the 21 accumulated body of knowledge over the last 15 years, which 22 incorporates WASH 1400, 30 odd or 20 odd or whatever the 23 number is of plant-specific PRAs that have been done, a lot'of 24 rumination, a lot of beer drinking, all those other things 25 that lead to wisdom on this whole business of quantitative -{ } i HERITAGE REPORTING CORPORATION -- (202)628-4888

300 1 risk assessment, and I have been in favor of using 2 quantitative risk assessment PRA more or less since the 3 beginning, although as you noticed I also had an inhibitory 1 1 4 effect on that at one stage of the game, but in that i 1 5 collection of information, I personally view that I will be i 6 happy to see what the peer review says is that 1150 is one of 7 the move flawed documents in that collection, so I wonder 8 whether in asking how one would use PRA and the accumulated 9 wisdom of the 15 years, one isn't putting too much specific 10 emphasis on how 1150 comes out in its PRA, in its peer review. 11 MR, STW.LO: What you are really doing is you are 12 probably making the judgment about the 20 odd volumes that 13 become the appendices to it where the real understanding and lh 14 knowledge is buried. 15 DR. LEWIS: Except in listening to the presentation, 16 there has been a lot of emphasis on, you know, procedure for 17 eliciting expert opinion, which is not my favorite part of the 18 subject anyway, and there just is a lot of stuff out there 19 which we should be using, and I hate to see it grind around 20 while we take this, to repeat myself, flawed document and try 21 to patch it up. I think we could patch it up because it is 22 the most recent thing that has been done, but however, I 23 extend a little bit beyond that. 24 MR. STELLO: All right. Maybe you can get the 25 Committee to write that down. gg HERITAGE REPORTING CORPORATION -- (202)628-4888

l l l 301 l' CHAIRMAN REMICK: Any further discussion of 1150 2 before we go on to other items? Yes, Chet. 7_s ( ' 3 DR. SIESS: I am still trying to understand-4 something. In SECY 89-058, there is very interesting' insights about the relative importance of the Station Blackout in the 5 l 6 BWRs and PWRs,.three PWRs and 2 BWRs. l 7 To what extent do these insights depend on what you 8 learned from 1150 and all this that is going with it? Could 9 not those insights have been made by anybody that had done a 10 half a dozen PRAs? 11 MR. MURPHY: Yes. There are a, an extension on an 12 insight that would have come from looking at the first 20 13 PRAs, but they are also true, the five we have just done. () 14 DR. SIESS: Are there any_of the insights in 05 that 15 you would say you couldn't have made without 1150? 16 MR. MURPHY: Yes. I think we are one of the first 17 studies that has looked in detail at battery depletion, and 18 the significance of that. In the risk analysis sequences you 19 lose AC power but have then, in the long term, the batteries 20 deplete and you lose DC power. 21 DR. SIESS: That doesn't take one of the codes Mr. 22 Catlin is concerned about, though, does it? 23 MR. MURPHY: I'm sorry? 24 DR. SIESS: That doesn't tal- 'e of the codes that fm 25 Mr. Catlin is concerned about? Battery depletion does? b HERITAGE REPORTING CORPORATION -- (202)628-4888

302 1 MR. MURPHY: No. It takes a detailed analysis of 2 the systems and the developing of the logic models and-- ,s () 3 DR. SIESS: Did the initial peer reviews have any- ) 4 problems with the calculations on battery depletion? 5 MR. MURPHY: The initial peer reviews of the 6 occident frequency analysis were not sharply critical of it in 7 their detail. The Chairman summary made it sound a lot worse. 8 When we got back in the bulk of the report and read exactly 9 what was said, their problem was mostly one of documentation 10 in that the peer reviewers could not find the information they 11 wanted and so they questioned whether we had done it right. 12 One of the things that has happened between draft 13 and final is that you will find that these reports are at f 14 least twice as big as the contractor' reports or at least twice %I 15 as big as they were before, and the reason is we are providing 1 16 the documentation that allows the peer reviewer to find the 1 l 17 information that they were looking for. It has been a front 18 end, it has been more a provide more documentation and reflect 19 the current design of the plant rather than a drastic change 20 in any of the models we had. 21 DR. SIESS: The reason I brought this up is it seems 22 to me that the discussion so far has been going along two 23 lines. One is is it possible to use the insights or 24 information for PRAs in the sort of things you have described, 25 and the other is is it proper to use insights from the NUREG gg L) HERITAGE REPORTING CORPORATION -- (202)628-4888

303 i 1 1150 PRAs? And those are almost two separate. questions. 2 CHAIRMAN REMICK: I agree with Joe. I think it is gg g 3 difficult to know where you draw the line. I agree with what 4 you are saying, j 5 DR. SIESS: Those are two questions. There is ao l 6 line between those two questions. The first question we could i 7 deal with without even knowing about 1150. How do you use-the j 8 insights from PRAs? Do you use the bottom line? Do you look 9 for dominant, pushing down the tempo, et cetera? The other is 10 simply'a matter of quality of a, quality scope or completeness 11 of the specific five cases in 1150. 12 CHAIRMAN REMICK: Any further discussion on 1150? 13 DR. LEWIS: Just one clarification-- () 14 MR. BECKJORD: There is a comment I would like to 15 make. I real?" wanted to take exception to what Hal Lewis 16 says about the flaws of 1150. 17 CHAIRMAN REMICK: Use your Mike. 18 MR. BECKJORD: 1150 is the only PRA that I know of 19 that has attempted to deal completely with the question of 20 uncertainties in severe accider :s, and that was a ] 21 recommendation that you yourself made some ten years ago, and 22 so I don't think it is flawed in that respect. 23 The other point is that I think 1150 goes much 24 further in the Level 2 and the Level 3, Level 1, 2 aspect of rN 25 the PRA, and if it is flawed, it may well be flawed, but it O HERITAGE REPORTING CORPORATION -- (202)628-4888

t 304-l 11-has'also gone further, and so.I would like to say that there l 2 are some very positive things that have been done. When'this 3 was reviewed by Professor Kastenberg and his committee, it was 4 not a consensus report, but Bill-Kastenberg made'it very. clear-5 to me that in all'of the things that they did,'they felt there 6 were!some very important steps forward in 1150. They l 7 concentrated on where they thought the difficulties were,~and L 8 he said I just want you to understand that, that we are not 9~ telling.you this is a lousy-job. We are trying to focus on1 10 where we think it~can be improved,: and I think that's an. 11 important comment to recognize. ' 12-I think that the people who have worked on it have. 13 'done their level-best to extend, to push the art and~ science eq t (,/ 14 of PRA further,1 and I think when-this is all said and done,. 15 that effort is going to be vindicated, but I am willing to-let 16 the chips fall where they may with the peer review. 17 -DR.' LEWIS: Neither of us has any choice but to let 18. the clips fall where they may, but firstaof all, I did not say 19 that 1150 was_ uniformly flawed, and so to say that there are 20 good things in it, of course.I agree. It is the most recent 21 thing that has been done, j 22 To say that it displayed the uncertainties more - 23 explicitly than others have is certainly right. There are 1 24 lots of things if I were biased in the direction of trying to i l 25 point out the good things on it, I could probably do a pretty l [} 1 HERITAGE REPORTIN CORPORATION -- (202)628-4888

'305 1 . good job. If I were biased in the direction of pointing'out 2 the bad things, I could probably do a pretty good job. g-3 It is a complex document like they all are. In the I 4 end there has to be an overall judgment of the: quality of the 5 things, and you have quoted Bill Kastenberg as casting his 6 overall judgment in a positive direction. I would like to 7 hear that from him. 8 My overall judgment is in the other. direction. I 9 have heard people say here that they think on balance, it is'a 10 much higher quality document than WASH 1400, and I really 11 don't agree with that. I think it is a more moderate i 12 document. There is no question about that, but some of the 13 newer cars aren't as good as the old cars, so newness is not I () 14 enough, and in the end there has to be a judgment of overall 15 quality just to satisfy people's egos for what is infinitely 16 more important--I think Vic has emphasized it--is to find the 17 things in it that tell you things that can help you maintain 18 and even improve perhaps the safety of the nuclear enterprise 19 and to do that with a certain amount of wisdom in which you 20 don't try to carry the whole darned thing with you, and try to 21 defend it as if it were a sacred book. It isn't a sacred 22 book. 23 MR. BECKJORD: And I don't think anybody is claiming 24 it is a sacred book. 25 DR. LEWIS:

Good, l

HERITAGE REPORTING CORPORATION -- (202)628-4888 1 J

na " 306 1 l 'HAIRMAN REMICK: Dr.-Siess?. 1 C '2 DR. SIESS: What'I am hearing'to.some extent bothers pp-3 me. I am hearing a discussion of'how good or:how perfect or 4' how far the' state of the-art and-science'of the PRAs should be 5 before I have heard any decision being made on what we are '6 going to:use them for. 7 It seems to me well, if, for example, you are, if-8' .you are'not going to use the results of PRA, fit really doesn't 9 make a lot of difference how good they are, how poor they are. 10 If you _ are going to use them-for plant-specific decisions, 11 then they better be defensible.right down.to magnitude, and I 12 don't,.I haven't; heard clearly how they are going to be'used. 13 I have. heard a proposal there without specific examples, but .()... 14 some'of the insights that are in that SECY don't require a 15 very elaborate PRA, and the insights that have been.made-16 without the benefits of external event PRA or without even 17 pointing out how that might change it, how are we going to 18 use--it is more important right now than how good it'is. 19 MR. STELLO: The context of putting those in this 20 paper which you briefed the Commission on the latest status, 21-the results, and I think I agree with you. Generally if you 22 have taken the remaining, all the other PRAs, I don't think I 23 would be wrong to say that you probably would have been able 24 to pick out these insights from the existing items. I have L 25 done--I believe the point you are making is correct. You HERITAGE REPORTING CORPORATION -- (202)628-4888 __-____-__-x--_-__--__-__.

307 1 could do that, but that's, it is not just these insights that r~'s - 2 we are talking about that are the kinds of information .(~) j 3 embodied within the document, and the question that is before l 4 us is in what way can you use all of that information while 5 the peer review is going on? 6 Example--way one, don't let anybody have a copy of 7 it. Prohibit anybody from reading it, and subject them to ten -8 lashes at the stake if you catch.anybody reading it. 9 DR. SIESS: If you let them read it, don't let them 10 understand it. That's better. 11 MR. STELLO: Next point, let them read it, but don't i 12 let them understand it. Then you can say well, they can read 13 it, even try to understand it, but you can't talk about it. 7"i (_) .14 You know, where do you draw'the line vbile the peer review is 15 going? 16 I say, I contend this document represents the best 17 safety information in understanding safety from the point of 18 view of PRA methodology results and analysis of experiments 19 that have been done over the last 15 years. That's what it is 20 all about. It has come to be called 1150, 21 Perhaps it would be nice to give it a new name. 22 Let's call it George, and say it is all of those things that 23 are the collection of the information that is there. What do 24 you do with it? /'N 25 CHAIRMAN REMICK: Well, we will address that d HERITAGE REPORTING CORPORATION -- (202)628-4888

308 1' question,.Vic, just as soon as we can do it in an orderly gS 2 manner. Get back to the, I would like to-- LJ 3 MR. BECKJORD: I would like to give Chet two points 4 to think about, and answer his question. 5 First of all, at the time when 1400 was written, 6 there was a lot that, there has been a great deal of' knowledge 7 about severe accidents developed since that time, and that 8 information through sometime in toward the third, fourth 9 quarter of 1988, that accumulated information and knowledge 10 about severe accidents is incorporated in 1150. 11 Do you agree with that, Joe? 12 MR. MURPHY: Yes. 13 MR. BECKJORD: To about October, November, somewhere () 14 in there, so that's a very important advance, and I think that i 15 we can use the insights that we can get from 1150 analysis 16 based upon that, and that can be applied along with other 17 things in making judgments about severe accidents. 18-The second point I think is Joe has made this a lot i 19 of details, but it is plant-specific insights. The five { reactors that we have studied have had a number of changes 20 21 made to equipment and systems as a result, and in the course i 22 of doing the 1150 analysis, and I think most everyone is in 23 agreement that those things have made safety improvements. It 24 is that kind of thing which can be done with other plants, and 25 I think both those points are very important to consider. HERITAGE REPORTING CORPORATION -- (202)628-4888

l. .1 .309. 7 .n 1-DR..SIESS: When you say that kind of thing that can 1 f ,a i 2 be done at other plants, these plantsLhave plant-specific PRAs L f-y 3,). j l ^% 3 and they made changes in those particular plants as a~ result . 1 4 of their.PRA..Is that what you say can be done to other 5-plants? q a - I 5 MR. BECKJORD: Yes. 7. DR. SIESS: Or these also can be applied to other 8 plants?. 9-MR. BECKJORD: I am saying that. I 10 DR. SIESS: The other one is IPE as I understand it. 11 MR. BECKJORD: That's right, and we are going to n 12 work on IPE now. That process is started. 13 DR. SIESS: I think everybody that ever did a PRA _( } 14 made some change to the plant as a result of it. Indian 15' Point, Zion, I go up and down the list, and nobody'has ever 16 questioned making changes to plants on.the basis of PRA or any. 17 kind of quantitative risk assessment. I think that's great. 18 CHAIRMAN REMICK: Let's give the EDO an opportunity 19 to discuss any other topics. 20 You mentioned one, Vic. I don't know if you want to 21 elaborate any more. We are having some problems, as I think-22 Mr. Fraley told you, with things either that we feel are 23 bypassing-the Committee,or we are not receiving an adequate 24 amount of time to consider, and I don't know if you plan to 25 discuss that any further. L L HERITAGE REPORTING CORPORATION -- (202)628-4888 1

310 i 1 MR. STELLO: Well, I have met with--there he is--Ray 2 and Jim Ball, am preparing a memorandum now to try to correct (~)g \\_ j 3 the problem. I agree it has been a problem. We are going to j I 4 fix it. l 5 DR. SIESS: We have had a memorandum. The problem i 6-has been people haven't been following it. I 7 MR. STELLO: Maybe they need to be reminded more l l 8 forcefully. 9 CHAIRMAN REMICK: Well, you realize we have some 10 short timetable and things the Chairman wants to get out. 11 MR. STELLO: This is a very good example, and we 12 tried to get here earlier than March to raise this with the 13 recognition that we are going to try to get to the Committee, .m() 14 the Commission in March. We failed'to do so. Well, the sense 15 of timing now, as I understand it, is Dr. Kerr waits until 16 April until he gets the report. It really means now in order 17 for the Committee to have all that information to make a 18 decision, we are talking maybe even June. 19 My guess is that makes it very difficult for the 20 Commission to have the benefit of the Committee's advice. Now 21 the Committee, Commission will have to decide well, there are 22 a lot, variety of things that they say. They will put the 23 peer review off, won't let the peer review begin. 24 DR. KERR: We have endorsed the peer review. 25 MR. STELLO: I understand that, but if, if we don't '} l l HERITAGE REPORTING CORPORATION -- (202)628-4888 l l

w-,--_-_ r 311 f 1 know-what'to do in the meantime,.msybe we just put everything 2 on hold unti1Lwe can. sort out what we do.in the meantime, b>~' 3 That's clearly an' option'for the Commission. I don't, I am 4 not suggesting they do'that for a moment, but the question is-S there. Should'you begin,. start, move forward now with the 6 peer review-and now set out what we are going to do in the 7 meantime? That's another choice. I I 8 DR. LEWIS:- What is the current schedule for the 9. peer review?. Is it underway? 10. MR. STELLO: No. We have, I th' ink--do we have j 11 .everybody agreed to? 12 MR. BECKJORD: I talked with--I have invited all_the 13 people, that we have nine. If you are interested, I can tell- -() 14 you who we have. 15 DR. LEWIS: No. 16 MR, STELLO: I don't think that would do--until we 17 have announced it. 18 MR. BECKJORD: Everybody has been appointed. After 19 the Commission is established, and there is a certain--you 20 have to go through some paperwork to get at it. 21 DR. LEWIS: We are not our own worst enemies, but we 22 are in there pitching for the job! 23 DR. SIESS: You made a good point at the beginning 24 of the ACRS cyclic nature, and the difficulty of dealing with [} 25 us in a timely manner, i l HERITAGE REPORTING CORPORATION -- (202)628-4888

9u 31 2 1 You need to add to that the problem we have'is it is 1 2 very difficult for us to do things both well and fast. You fs0 3 have got a choice. 4 MR. STELLO: I don't accept that. I think, I think 5 one can still do them well and be reasonably expeditious about I 6 getting them done. 7 DR. SIESS: I said we can't. 8 MR. STELLO: I have seen the Committee do it, I 9 think. 10 DR. KERR: Let's take the-- 11 DR. SIESS: Five years we could do it. We can't-- 12 DR. KERR: Let's take the advice you want from this i 13 body. I don't think we need necessarily to meet with the () 14 staff to give you seme comments, but I do think that we need 15 to spend more than 30 or 40 minutes formulating what we are 16 going to say. 17 I would anticipate -in a subcommittee which would be 18 as many of the Committee members as we can get together, 19 spending about a full day discussing this and then writing 20 something, but in order to do that we have to find the 21 schedules of this group and our--on some significant fraction 4 22 of the group and get together, and we then have to present it 23 to the Full Committee in order for there to be a Committee ) 24 letter. That is going to take a while inevitably. 25 MR. STELLO: I would only ask you try to have it HERITAGE REPORTING CORPORATION -- (202)628-4888

_7 313 1 done as quickly as you can'do it and still do a good job. f T, 2 DR. KERR: That's what I thought you would say. () 3 CHAIRMAN REMICK: Going back on the broader 4 question, I have here in front of me a proposed schedule for 5 some of these items that I guess the Commission wants out 6 soon, and just scanning through that, we found that a couple 7 of problems. I just want to point them out to you. 8 As an example,twith the suggestion that it seemed to 9 me we have got to get back and still work out details of this 10 particular one on the PWR ice condenser recommendations--as we 11 read it, there will be a public workshop on 5-89. The staff 12 document would come to ACRS seven months later, seems like a 13 long period of time, and then that is going to the Commission /'% (_j 14 one month, that so we have one month to-- 15 DR. SIESS: Is that when you expected it to get to 16 us? 17 CHAIRMAN REMICK: That has been resolved. That's 18 when that comes to us. Comes to us, yes. 19-MR. STELLO: Those are the kinds of things exactly I 20 had in mind when I said we will try to fix it to the best of 21 our ability. 22 CHAIRMAN REMICK: We get back with your staff on 23 that. 24 MR. STELLO: We might have to find a new way to deal j ("i 25 with having an opportunity for us to provide it, documents, to \\_/ HERITAGE REPORTING CORPORATION -- (202)628-4888

314 { 1 the Committee that are clearly draft and have not had and at i I } 2 least to get something to the Committee to get them started, 3 and I think it will make it a lot easier than trying to deal 4 with the final document. We are going to have to do something 5 that we probably haven't done in otder to accommodate that. I 6 CHAIRMAN REMICK: Yes, in this interim period.. I i 7 MR. STELLO: That is correct, yes. 8 DR. LEWIS: I agree with you that at some point, you 9 have to start working together, which means that we should get 10 things when they are not in their final form and you should 11 respect the fact they are not in their final form so we can be 12 thinking they might even be helpful to you. 13 We won't hold you to these things, but in the end, lll 14 the Commission is going to have to regulate nuclear power 15 without going on our, on a monthly cycle, and that's sort of 16 their job. We can only function at a certain rate. 17 I do want to agree with them on one point. That is 18 that things can be done well and fast. I have seen any number 19 of things that we are fortunate are not made very much worse 20 by long deliberation, in which the first response is really a 21 pretty good one. 22 DR. SIESS: As far as one problem we used to have 23 with getting early documents from staff was that they weren't 24 available for the public yet and we had problems with 25 subcommittee meetings. If we had an open subcommittee HERITAGE REPORTING CORPORATION -- (202)628-4888

\\ 315 1 meeting, we couldn't deal with preliminary documents. 2 Do we have that straightened out now about having 3 closed subcommittee meetings to consider early staff 4 positions? 5 MR. FRALEY: That is pretty well straightened out. 6 DR. SIESS: Does everybody now know it? 7 CHAIRMAN REMICK: We certainly have been doing it. 8 Vic, did you have other topics? 9 MR. STELLO: No. I wanted to know what else the 10 Committee may wish to bring up to us. 11 CHAIRMAN REMICK: Subjects, gentlemen, you would 12 like to discuss with the EDO or staff, senior staff, while 13 they are here? Yes? lll 14 DR. SHEWMON: One question about what the staff is 15 doing or who to talk to with regard to containment criteria; 16 did that get straightened out, or is that something worth 17 asking about? 18 DR. SIESS: He won't know. 19 CHAIRMAN REMICK: Oh, yes. 20 MR. BECKJORD: What is the question. 21 CHAIRMAN REMICK: Go ahead, Paul. 22 DR. SHEWMON: I'm afraid I said everything I can, 23 CHAIRMAN REMICK: We are thinking about starting an 24 effort to look at what should be the design basis of 25 containment structures for the future, that the broader HERITAGE REPORTING CORPORATION -- (202)628-4888

l 316 1 1 question, should one consider severe accidents and so forth, 2 and the defining performance criteria or design criteria. (~)'s ( 3 It is our impression that there is not much 4 attention being given to that nationally, so we want to start 5 an effort to start thinking about that. 6 One of the first things-we want to do is have a 7 subcommittee and talk to the appropriate people on the staff 8 who might be knowledgeable not just about what they are doing, 9 but who might have got en, given some philosophical thought to 10 containment structures of the future, and how should they be 11 designed, and so forth, and we thought this would be a good 12 opportunity to raise that question with you. You need not 13 answer it now, but get back to us on who would be the proper p) (_ 14 people of the staff to have come in and talk to us. 15 MR. STELLO: Okay. 16 MR. BECKJORD: We can give you, have that name. I 17 think we are ready to do that. 18 CHAIRMAN REMICK: That is falling under the 19 subcommittee chaired by Dave Ward, so who is the ACRS staff 20 member on that? MR. FRALEY: Paul Boehnert, or Dean Houston. 21 22 CHAIRMAN REMICK: So if you would have somebody get 23 back to Dean-- 24 DR. SIESS: How is your reorganization going? (~T 25 MR. STELLO: With the-- O t HERITAGE REPORTING CORPORATION -- (202)628-4888 L________-__---__ a

i l \\ l 317 1 DR. SIESS: New deputies, 2 MR. STELLO: Yes. It is,in place. Hopefully it-p j-)J. 3 will allow all of us to have more time to get together, kick l 4 around the issues. Right now, it's getting everything to i 5 work, just gone into effect. It is too early to be able to 6 have much difference. 7 Jim has had a little bit more time to look at some 8 of the things. I think overall, though, that's a small part. 9 The major effect of the reorganization that folded IE into NRR e 10 and got program offices to be responsible for the reactors and 11 materials, I would say that's working much better than even I 12 thought it would work. It's really going, very, very ws11. 13 The regions, when a problem comes up with a licensee, they get' () 14 an answer and it is an Agency answer, and it speaks for 15 everybody in contrast to--I don't know if you have heard 16 problems before that give one answer from the region and maybe 17 another answer from IE headquarters and get a third answer 18 from NRR, and we had problems, and I think that kind of 19 problem, that kind of has just gone. 20 DR. SIESS: One other question--have you given any 21 thought to the allocation of responsibilities for advice 22 between the ACRS and the ACNW? 23 We have been looking at what we thought the f y 24 Commission told ACNW that it should do certain things, and 25 right now we are not quite sure. We begin to look at--what is .r~s - g HERITAGE REPORTING CORPORATION -- (202)628-4888

318 1 your idea about thati 2 MR. STELLO: My view, my view of the ACNW, they are 3 going to be extremely busy dealing with the high-level waste 4 issue, and they are going to I don't think have a great deal 5 of time to do a great deal of other things, and that's going 6 to get very, very busy in the not too distant future. 7 I really don't see them having a great deal of time 8 to do a lot of other things. 9 DR. SIESS: Like transportation? 10 MR. STELLO: Like anything else; I think they are 11 going to be very, very busy. I'm sure they will do some of 12 them. 13 DR. SIESS: Is MRS part of high'-level waste? () 14 MR, STELLO: It is embodied within'that legislation 15 and that clearly will come down. 16 DR. SIESS: Off-site storage? I put the question 17 once when does spent fuel become high-level waste? When it 18 leaves the pool or when it leaves the site? Well, think about 19 it. 20 MR. STELLO: I think that the way the law is written 21 right now, and I'm not a lawyer, but I would like--my 22 recollection of the way things go is the minute it comes out 23 of that reactor, it is destined to be treated as high-level 24 waste, destined for the Department of Energy to take it over 25 at some point in time for ultimate disposal, so once it is } HERITAGE REPORTING CORPORATION -- (202)628-4888

319 1 removed from the reactor vessel-- } 2 CHAIRMAN REMICK: In the opent fuel? 3 MR, STELLO: I don't know how else--yes, I would 4 have to say when it is there, in the spent fuel, after it has 5 been discharged, it is clear that that commitment is made at 6 that point that DOE will take it and it will be disposed of. 7 CHAIRMAN REMIC : From the reactor pool or from the 8 spent fuel pool? 9 MR. STELLt FiE actually doesn't take it until it 10 is received either ai "EU3 o~ Yucca Mountain when they actually 11 take possession of it. 12 DR. SIESS: The geestion was asked in the context of 13 when the ACNW takes over responsibility from ACRS. llh 14 MR. STELLO: If I had known you were asking me that 15 question--that's such a hard blend, well, do you need to have 16 an answer? I don't know why there is a need for an answer. 17 DR. SIESS: There has been questions of on-site 18 spent fuel storage. There are questions of transportation. 19 CHAIRMAN REMICK: Hot particles. 20 DR. SIESS: Tne Commission told them to do 21 transportation. They don't want to do transportation. The 22 McCloskey Amendment is transportation, and it is just right 23 now there is a little bit of confusion between the two 24 committees, 25 MR. STELLO: I wouldn't, you know, I can't do--I g HERITAGE REPORTING CORPORATION -- (202)628-4888

320 4 t l' have never been on'the ACRS. I would think it would be -l j 2_

unnecessary.to draw hard, rigid lines, you know, exactly when

-3 should the ACRS say I'm no longer concerned with what is 4 happening with dead spent fuel. I don't.think-- 5. DR. SIESS: We don't want things to. fall in the 6-cracks. ~ 7 MR. STELLO: I don't think so, but I would have a. 8 hard time believing that no matter how that question is .9 answered, no matter how you answer it, that'this Committee ] 10 won't. continue to be following it, interested, no matter what j 11 is going to happen. 12 DR. SIESS: It's nice to know what the scope is. 13 For example,'I have had transportation. I have-cot a stack'of )) 14 reports like that. If the Committee is going to have 15 transportation, I can throw those reports out. That's nice, i i 16 you know. -The next three years I have got tolget rid of a ton 17 of. paper. 18 CHAIRMAN REMICK: Now pre-conceived view.on that? 19 MR. STELLO: No. 20 CHAIRMAN REMICK: Vic, one quick' question--we have 21 been looking at this. this is the NRC regulatory conference a 22 conflict in April. A number of members I think will want to 23 attend, but one of the questions that came up yesterday, we i-24 thought this was going to b6 a discourse between licensees and 25 so forth, but we see that the program lists only NRC people.. 4 HERITAGE REPORTING CORPORATION -- (202)628-4888 .o =_-

321 1 Is it going to be a discourse between licensees, or 2 is it going to be a monologue of NRC? 3 MR. MURLEY: The idea, Mr. Chairman, was for us to 4 portray the, and get out on the table in kind of a formal way 5 what our current concerns are, but the way the meeting will be 6 conducted, we will try to elicit a lot of questions and 7 answers and give and take. We are getting a lot of interest 8 so far from licensees and even other organizations and even 9 some overseas orgt;nizations, so the intent is to have it be as 10 much as we can a give and take dialogue with, of course, us 11 leading the discussion with some policy thoughts. 12 CHAIRMAN REMICK: There will be time for a 13 discussion after the presentations by the staff? llh 14 MR. MURLEY: Absolutely. Those times in that 15 booklet are meant to include probably a third of the time will 16 he for questions and answers, discussion. 17 CHAIRMAN REMICK: Hal? 18 DR. LEWIS: Let me ask Vic a safety question since 19 he is here. 20 I have heard rumors that there is some difference in 21 views--that may be an exaggeration--between NRC and DOE on the 22 question of whether containment is necessary at all, no matter 23 how small the core melt frequency is. 24 You know, is their there a staf f position or3 that? 25 MR. STELLO: Yes. ggg HERITAGE REPORTING CORPORATION -- (202)628-4888

) 322 1 DR. LEWIS: What is it? I 2 MR. STELLO: Let me give you the background first 3 because I think it is important, 4 DR. LEWIS: Oh, shucks! You don't want to just 5 answer the question? 6 MR. STELLO: No. Without the the background, I 7 think it will be a problem. 8 We were doing the review of the MHTRG, and as you 9 know, that was a commercial version. The ACRS itself looked 10 at it. That particular design did not include a containment 11 concept. The Department of Energy made a recommendation to go 12 forward with the MHTRG as a production reactor in Idaho, below 13 grade, and in fact would put a containment <P) on it. llh 14 Question--how come you are going forward with the 15 commercial without, and with the NPR on the basis of-- 16 CHAIRMAN REMICK: We asked them that same question. 17 MR. STELLO: I said look, I don't want to go forward 18 and take a final position on this matter until I have had that 19 explanation fully out on the table. I'm not pre-judging that, 20 a reactor concept without, one ought to on its face be 21 rejected, but in this case, where there is clearly reactor 22 with a lot of similarities, two different ways, I think there 23 needs to be an explanation. 24 They have, the department started studies and they 25 have indicated they will provide them to us in June. That ggg HERITAGE REPORTING CORPORATION -- (202)628-4888

l 323 f l 1 will give us the technical understanding as they see it,-and (~S -2 basically left it open. iv' 3 Now there are various schemes that are now being 4 proposed even with the NPR of quasi-confinement buildings with 5 spaces, tunnels, and vents, sand filters, and that kind of l 6 thing, that they are looking at this and they are also looking. 7 at further enhancements in terms of decay heat removal systems 8 and things that they need to do.. 9 When those studies are complete, they will get it I l 10 back to us, so the official position is~we will not take a 11 position until we have those studies done one way or the 12 other. l 13 DR. LEWIS: On the NPR, they have made explicit t3 (j 14 announcement they are going to containment. 15 MR. STELLO: I am telling you that is modulating 16 right now. 17 DR. LEWIS: I have to put on the record a little bit 18 of a conflict here because I'm Chairman of a subcommittee, of 19 John Hearns' committee responsible for the NPR and they sure 20 haven't told me that. 21 MR. STELLO: I say modulating. What did it mean 22 containment? What kind? 23 DR. LEWIS: They don't know. 24 MR. STELLO: They are now looking at it and I am i (~N, 25 telling you what I am hearing is what I have just said, so now (/ HERITAGE REPORTING CORPORATION -- (202)628-4888

324 j I 1 they never said it is going to be a five-foot concrete, you 2 know. They never said that. It was I think intended to mean 3 a containment kind of thing. They are now looking at what 4 that containment system is going to look like, and variation. 5 DR. SIESS: You don't know what it is? 6 MR. STELLO: No. They don't, either. DOE doesn't 7 know. 8 DR. LEWIS: That is correct, but your position is 9 that it is a contradiction? 10 MR. STELLO: We are not going to make a decision 11 until we have had the benefit of the rest of that information, 12 that is correct. 13 D". LEWIS: Are going to wait for the facts?! h 14 MR. STELLO: Yes. 15 CHAIRMAN REMICK: We have another minute or two. 16 Anybody else have another topic for the senior staff over 17 there? 18 MR. STELLO: Let me take the last minute to say Hal, 19 on the record, you asked me at the beginning of the meeting if 20 I have ill feelinos of your comment, and the answer is no. 21 CHAIRMAN REMICK: Do you have broad shoulders? ~ 22 MR. STELLO: Or thick skin. 23 DR. LEWIS: More than yout akin is thick! 24 MR. STELLO: Now I may take back w at I just said a 25 moment ago! gg HERITAGE REPORTING CORPORATION -- (202)628-4888

l 325 j 1 CHAIRMAN REMICK: Bill? 2 DR. KERR: I just want to remind you of the story 1 3 that actually happened. A colleague of mine was in France 4 when George Wallace was shot during the early election 5 campaign, and he said, he wrote me a letter and said I came 6 out of the office the next morning, and my French colleagues 7 said why are you Americans so violent? And he said I couldn't 8 think of any answer, so I hit him in the mouth! 9 CHAIRMAN REMICK: We do want to thank you and your 10 senior personnel for coming down. 11 MR. STELLO: Our pleasure; we look forward to 12 reading your letter from this meeting on that issue. 13 CHAIRMAN REMICK: Fifteen minute break. llh 14 (Whereupon, at 2:30 p.m., the recorded portion of 15 the meeting was adjourned.) 16 17 18 19 20 21 22 23 24 25 (Il "" "^ " " -- (202)628-4888

1 CERTIFICATE 2 0<- ~. 3. This is to certify that the attached proceedings before the 4 United States Nuclear Regulatory Commission in the matter of: 5 Name: Advisory Committee on R,eactor-Safeguards, 347th General Meeting 6 7 Docket Number: 8 Place: Bethesda, Maryland 9 Date: March 10, 1989 10 were held as herein appears, and that this is the original i 11 transcript thereof for the file of the United States Nuclear 12 Regulatory Commission taken stenographically by me and, 13 thereafter reduced to typewriting by me or under the direction i 14 of the court reporting company, and that the transcript is a j 15 true and accurate record of the foregoing proceedings. 16 /S/ m 17 (Signature typed): Catherine S. Boyd 18 Official Reporter 19 Heritage Reporting Corporation 20 l 21 l L 22 23 l 24 25 Heritage Reporting Corporation p) (202) 628-4888 (, l

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~ 1. LEAK BEFORE BREAK TECHNOLOGY, J ADDITIONAL APPLICATIONS O l CARL W. HIRST WESTINGHOUSE ELECTRIC CORPORATION 1 i .O

OUTLINE ~ lO: { ) 0 INTRODUCTION ) 0 INTERPRETATION OF RULE CHANGE 0 CURRENT LOCA ANALYSIS CONSIDERATIONS I 0 LOCA SAFETY INJECTION SYSTEM i O 0 CONTAINMENT SYSTEMS & ENVIRONMENTAL REVIEW 0 NEW PLANT DESIGNS l 0 CONCLUSIONS O

r ? > INTRODUCTION. ~ v 0 REVIEWED FOR APPLICATION TO WESTINGHOUSE DESIGNED PLANTS ) 0 IMPACT ON OPERATING PLANTS - SAFETY INJECTION SYSTEMS - CONTAINMENT SYSTEMS O ENVIRONMENTAL QUALIFICATION O POTENTIAL IMPACT ON NEW PLANTS 0 APPROVED APP K ECCS MODELS 0 BEST ESTIMATE LOCA METHODOLOGY O \\

~ INTERPRETATION OF GDC 4 RULE CHANGE O O PRESENT RULE USING LBB MAY ELIMINATE DYNAMIC EFFECTS OF RUPTURES IN PRIMARY COOLANT PIPING - FEW PLANTS APPLIED LBB TO PRIMARY BRANCH LINES 0 PROPOSED CHANGE O ANALYSIS MUST DEMONSTRATE ECCS PERFORMANCE FOR RCS BREAKS OF ALL SIZES UP TO THE LARGEST BREAK NOT DISPOSITIONED BY LBB CONTAINMENT ANALYSIS FOR EQ WOULD CONSIDER RUPTURES IN CARBON STEEL MAIN STEAM LINES UP TO.THE LARGEST BREAK NOT C) DISPOSITIONED BY LBB

<1 CURRENT LOCA ANALYSIS CONSIDERATIONS .j ANALYSIS TO DEMONSTRATE ECCS PERFORMANC] 0 ALL BREAK SIZES IS REQUIRED FOR LICENSING PER APP K 0- . SEPARATE EVALUATION MODELS USED FOR LARGE AND SMALL BREAK LOCAs O LBLOCA (>l SQ FT) FLUID BEHAVIOR DOMINATED BY INERTIAL EFFECTS O 0 INTERMEDIATE BREAKS (1 SQ FT > B > 8 IN DIA) INFLUENCED BY INERTIA AND GRAVITY - HAVE RECEIVED LIMITED ATTENTION - MAY BECOME LIMITING WHEN LBLOCA ELIMINATED 0 SMALL BREAKS (s 8 IN) GIVE LOW FLOW RATES, SLOW DEPRESSURIZATION AND DISTINCT MIXTURE LEVELS g

~ SAFETY INJECTION SYSTEM O 0 ' CAPABILITY TO MITIGATE CORE THERMAL TRANSIENTS FOR A SPECTRUM 0F BREAK SIZES 0 ALL MAJOR'SI COMPONENTS PERFORM SIGNIFICANT FUNCTIONS THROUGHOUT THE LOCA BREAK SIZE SPECTRUM 0 HHSI PRIMARILY FUNCTIONS TO MITIGATE SBLOCA - 2 TO 4 PUMPS - 1400 PSIA SHUT 0FF HEAD 0 SINCE GDC 4 DOES NOT AFFECT SMALL BREAK LOCA NO RELAXATION IN HHSI PERFORMANCE IS ANTICIPATED i O

SAFETY INJECTION SYSTEM (CONT'D) ACCUMULATORS SOURCE OF HIGH PRESSURE WATEd O IN SBLOCA APP K ANALYSIS 0 MANY SMALL BREAK LOCAs CONTROLLED / TERMINATED BY ACCUMULATOR INJECTION 0 MUST BE RETAINED BY CURRENT PLANTS INDEPENDENT OF LARGE BREAK LOCA CONSIDERATIONS (D 0 'ALSO USED TO REFILL REACTOR FOR INTERMEDIATE BREAK LOCAs 0 SINCE THEY ARE PASSIVE THEY ARE VALUABLE IN PROBABILISTIC ASSESSMENTS OF ECCS BEHAVIOR O

SAFETY INJECTION SYSTEM (CONT'D) NO RELAXATION OF ACCUMULATOR REQUIREMENTS IN EXISTING PLANTS IS ANTICIPATED 0

HOWEVER, THROUGH SMALL AND INTERMEDIATE BREAK ANALYSIS MAY RELAX SETPOINT REQUIREMENTS -

MAY HAVE ONE OF N OUT OF SERVICE WITH NO LARGE BREAK LOCA j 0 LHSI PERFORMANCE REQUIREMENTS COULD BE IMPACTED - SIGNIFICANT REQUIREMENTS WOULD REMAIN TO MITIGATE SURGE LINE OR SIMILAR SIZE BREAK l 0 LHSI FLOW SOMETIMES NEEDED IN SMALL BREAK CASES TO AUGMENT HHSI FLOW WHEN ACCUMULATORS ARE EMPTY O i

SAFETY INJECTION SYSTEM (CONT'D) 0 LHSI PUMPS MUST OPERATE INDEFINITELY FOR P0 9 LOCA COOLING FOR ALL SIZE BREAKS 0 FOR MOST W PLANTS LHSI PUMPS SERVE AS THE NORMAL PLANT C00LDOWN SYSTEM 0 NO SIGNIFICANT REDUCTIONS IN LHSI PUMP PERFORMANCE ACCEPTABLE FOR CURRENT PLANTS O O

SAFETY INJECTION SYSTEM

SUMMARY

EXISTING PLANTS MUST MAINTAIN HHSI, ACCUMULATOR AND LHSI CAPABILITY I 0 BENEFITS IN RELIABILITY MAY BE REALIZED BY MODIFYING TECH SPEC SI FLOW RATES AND JUSTIFYING LESS SEVERE DIESEL GENERATOR START TIMES r 0 EXISTING SI SYSTEM EQUIPMENT REMAINS I C) NECESSARY FOR EXISTING PLANTS l 0 COMPARATIVE BENEFITS MAY BE OBTAINED FROM APPLYING ADVANCED LOCA MODELING TECHNOLOGY l { O

CONTAINMENT SYSTEMS AND ENVIRONMENTAL REVIEW ~ j db 0 LBLOCA TRADITIONALLY THE DESIGN BASIS ACCIDENT FOR CONTAINMENT DESIGN AND EQ O DELETION OF LBLOCA WILL DECREASE SEVERITY OF POST LOCA TEMPERATURE / PRESSURE RESPONSE 0 STEAMLINE BREAK WOULD STILL HAVE TO BE ANALYZED O 0 STEAMLINE BREAK TRANSIENTS 0FTEN COMPARABLE TO LBLOCA TRANSIENTS - SOMETIMES LIMITING 0 BENEFIT FOR LBB ON STEAMLINE BREAK HAS NOT BEEN QUANTIFIED 0 MASS AND ENERGY RELEASE FOR NEW LIMITING LOCA MUST CONTINUE TILL EQUILIBRIUM IS ACHIEVED gg

CONTAINMENT SYSTEMS AND ENVIRONMENTAL REVIEW (CONT'D) \\ O r 0 SHORT TERM TEMPERATURE (THRU 300 SEC) IS ESTABLISHED BY STEAM LINE BREAK 0 BENEFIT OF LBB FOR EQ CURVES LIMITED TO INTERMEDIATE PORTION OF TRANSIENT CURVE (300 TO 10,000 SECONDS) g WITHOUT LBLOCA TEMPERATURE BENEFIT OF 40 DEGREES AT 1,000 SEC MAY RESULT I 0 WITHOUT LBLOCA TIME-AVERAGE TEMPERATURE BENEFIT OF 18 DEGREES (300 - 10,000 SEC) 1 0 LONG TERM POST LOCA VALUES (10,000 SEC) WILL REMAIN UNCHANGED f o E

NEW PLANT DESIGNS 0 APWR + SI SYSTEMS SIMILAR TO EXISTING PLANT . y CONFIGURATIONS l +

HHSI, LHSI AND ACCUMULATORS

/ + IN-CONTAINMENT TANK + HHSI MUST BE MAINTAINED FOR SBLOCA + ACCUMULATORS REQUIRED FOR IBLOCA + REDESIGN COULD JUSTIFY HHSI ELIMINATION OR RE0 OPTIMIZATION 9 { h

REW PLANT' DESIGNS k AP 600 + PASSIVE SAFETY INJECTION - CORE MAKEUP TANK (RCS PRESSURE) - IN-CONTAINMENT RWST - ACCUMULATORS O + KEY CONSIDERATION - DEPRESSURIZATION OF RCS TO CONTAINMENT ATMOSPHERIC PRESSURE + IRWST PROVIDES LONG TERM INJECTION AND COOLING BY GRAVITY O

NEW PLANT DESIGNS L 0-AP 600 (CONT'D) 0 0 l + - SMALL BREAK LOCA IS THE TRUE DESIGN BASIS TRANSIENT l + PROBABLE THAT ACCUMULATORS UNNECESSARY I I + NEED TO CONSIDER MAIN STEAMLINE BREAK i + MUST PROVIDE EXTENDED HEAT REMOVAL O FOLLOWING LOCAs + PASSIVE CONTAINMENT SAFEGUARDS AND EQ CURVES NOT EXPECTED TO BE ALTERED 1 1 ~ O

CONCLUSIONS k POTENTIAL BENEFITS FOR W COMMERCIAL PWRs + RELAXATION IN TECH SPEC PEAKING FACTORS + INCREASED RELIABILITY FROM INCREASED EMERGENCY DIESEL START TIMES + SOMEWHAT REDUCED EQ ENVELOPE CONSTRAINTS ON ECCS REMAIN FOR SMALL LOCAs 0 NO SAFETY SYSTEMS MADE OBSOLETE BY ELIMINATING LBLOCA 0 NEW PLANT ANALYSIS MAY BE NEEDED FOR INTERMEDIATE SIZE LOCAs 9

CONCLUSIONS (CONT'D1 0 BEST ESTIMATE LOCA METHODOLOGY GIVES O COMPARABLE OPERATING MARGIN BENEFITS 0 OVERALL PLANT SIMPLIFICATION BENEFITS NOT MAJOR 0 EQ BENEFITS HAVE NOT BEEN QUANTIFIED, BUT APPEAR SMALL O x 0 a

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