ML20132G772
| ML20132G772 | |
| Person / Time | |
|---|---|
| Issue date: | 12/18/1996 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| ACRS-T-2087, NUDOCS 9612270038 | |
| Download: ML20132G772 (33) | |
Text
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Officirl Trcnscript cf Prscocdings NUCLEAR REGULATORY COMMISSION O
ACPS7~208
Title:
Advisory Committee on Reactor Safeguards -
Thermal Hydraulic Phenomena Subcommittee TRO4 (ACRS)
RETURN ORIGINAL 8"
' Docket Number: (not applicable) [ 3 7 jy8 415-7130 THANKS1 h
Location: Rockville, Maryland O Date: Wednesday, December 18,1996 1
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- l j Work Order No.: NRC-948 Pages 1-26
' ' Closed;Lw es 27-@9 '"
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1 4
1 UNITED STATES OF AMERICA g^3 2 NUCLEAR REGULATORY COMMISSION N_/l 3 +++++
4 MEETING 5 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 6 THERMAL HYDRAULIC PHENOMENA SUBCOMMITTEE 7 +++++
8 WEDNESDAY 9 DECEMBER 18, 1996 10 +++++
11 ROCKVILLE, MARYLAND 12 +++++
13 (3
14 The subcommittee met at the Nuclear Regulatory I
15 Commission, Two White Flint North, Room T2B3, 11545 ,
16 Rockville Pike, at 8:30 a.m., Ivan Catton, Chairman, j 17 presiding.
18 19 COMMITTEE MEMBEES,1 l 20 IVAN CATTON CHAIRMAN 21 MARIO FONTANA MEMBER 22 THOMAS S. KRESS MEMBER 23 ROBERT L. SEALE MEMBER 24
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2 1 ACRS STAFF PRFSENT:
2 Paul Boehnert
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4 ACRS CLNSULTANTS PRESENT:
5 Virgil Schrock 6 V.J. Dhir 7 Novak Zuber 8
9 ALSO PRESENT:
10 George Bankoff 11 Alan Levin 12 Larry Hochreiter
,_ 13 Gene Piplica 14 Marino diMarzo 15 Bill Brown 16 Mike Loftus 17 18 19 20 21 22 23 24
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3 1 A-G-E-N-D-A g ~., 2 Acenda Item Pace
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'c) 3 Chairman's Introduction, I. Catton 4 4 NRC Objectives for PIRT/ Scaling Report 5 A. Levin _
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8 9
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4 1 P-R-O-C-E-E-D-I-N-G-S
,x 2 (8:36 a.m.)
(V) 3 CHAIRMAN CATTON: The meeting will now come to 4 order. This is a meeting of the ACRS Subcommittee on 5 Thermal Hydraulic Phenomena. I am Ivan Catton, Chairman 6 of the Subcommittee.
7 The ACRS Members in attendance are: Mario 8 Fontana, Tom Kress, and Bob Seale. ACRS Consultants in 9 attendance are V.J. Dhir, Virgil Schrock, and Novak Zuber.
10 We also have in attendance Dr. S. George Bankoff who is 11 observing this meeting on behalf of the Office of Nuclear 12 Regulatory Research's Nuclear Safety Research Review 13 Committee.
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-' 14 The purpose of this meeting is to review the 15 Westinghouse Scaling and PIRT Closure Report that 16 addresses the relevant issues associated with the AP600 17 reactor coolant system. The Subcommittee will gather 18 information, analyze relevant issues and facts, and 19 formulate proposed positions and actions as appropriate, 20 for deliberation by the full Committee.
21 Most of this meeting will be closed to the 22 public to protect information deemed proprietary to the 23 Westinghouse Electric Corporation.
24 Paul Boehnert is the Cognizant ACRS Staff (n,) 25 Engineer for this meeting. The rules for participation in i NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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i 5 I 1 today's meeting have been announced as part of the notice 2 of this meeting previously published in the Federal (7
v w) -
3 Reaister on November 27, 1996.
4 A transcript of the meeting is being kept and 5 will be made available as stated in the Federal Reaister 6 notice. It is requested that the speakers first identify 7 themselves and speak with sufficient clarity and volume so 8 that they can be readily heard. We have received no 9 written comments or requests for time to make oral 10 statements from members of the public.
11 This meeting is a follow-on to our meeting of 12 May 9 through 10, 1996. At the conclusion of that 13 meeting, we decided that before we were to meet again, I\ ') 14 Westinghouse would develop convincing arguments for 15 completeness and that the staff would have reviewed them 16 so that we could all agree. This was to be accomplished 17 via a combination of PIRT, scaling, and common sense.
18 Further, we are to limit this to the primary system, I 19 leaving containment issues to another time, i
20 Westinghouse would like the ACRS to reach ;
21 closure on the acceptability of the PIRT/ Scaling Report, j j
22 WCAP-14727, and on the acceptability of the associated l
l l
23 test program described in WCAP-14772.
24 Before we start, I have a few comments and
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6 1 is over. First, I would like some assurance that the ,
1 1
rx 2 large break LOCA is treated the same way that the three
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3 and four loop plants were and that the documentation 1
4 referred to in WCAP-14727 has been cleaned up for promises l
5 made at that time, i 6 In the small break LOCA section, it is stated 7 that the NOTRUMP code is an approved code. From what i i
l 8 rumors I have heard, there have been a number of major l
9 changes during the past few years that are not reflected 10 in the documentation available to us. These changes leave 1
11 us with a code of unknown pedigree. ,
l 12 During a small break LOCA, the possibility of l 13 two-phased counter current flow exists with the liquid
(\' )
14 phase being sub-cooled. University of Maryland tests show 15 that this can lead to rather strange behavior and maybe ;
1 16 Westinghouse could comment at some point. I saw Professor 17 diMarzo here. Maybe he could also comment.
18 Under transients, steam generator secondary 19 site heat transfer shows high on PIRT charts. I would 20 like a brief explanation of what calculating it entails.
21 Horizontal pipe stratified flow is also 22 important to long-term cooling, and may well help explain 23 some of the behavior seen at OSU.
24 SPES-2 is said to be used to validate LOFTRAN-n k_,) 25 AP LOFTTR2 and NOTRUMP, for transients, steam generator, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE.. N W (202) 234-4433 WASHINGTON. D C. 20005-3701 (202) 234-4433
7 1 tube rupture and small break LOCA. Given the problems t'"s 2 with SPES-2 that are outlined in the document, what are
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3 the arguments for doing this?
4 A large number of comparisons are made of OSU S and SPES results with a NOTRUMP AP600. In some cases, 6 there are significant differences. The question is, has 7 NOTRUMP been used to predict OSU and SPES and have 8 comparisons with data been made? It seems to me that 9 there are several parts to this question that will have to 10 be addressed at some point.
11 It is difficult to argue that you can 12 extrapolate to a full scale AP600 li there is integral 13 system behavior you can not simulate or that you can not (A)
'" 14 explain.
15 Before we start, I would like to give my 16 colleagues a chance to add to what I have said or maybe 17 tell me if I'm out of line or off or whatever. We'll 18 start with Virgil, seeing as how he is furthest away.
19 MR. SCHROCK: I think you have covered it much 20 better than I could have.
21 CHAIRMAN CATTON: Novak?
22 MR. ZUBER: I shall withhold my comments for j 23 the end of the meeting. I don't want to --
24 CHAIRMAN CATTON: Prejudice?
/~x e 25 MR. ZUBER: No, I don't want to start, I mean l NEAL R. GROSS I COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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dl 1 a confrontational approach, except let me say it was a fs 2 very disappointing docur"nt, especially this last one.
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3 Let me just stay at this, and we can discuss it.
4 CHAIRMAN CATTON: Okay. V.J.?
5 MR. DHIR: Yes. I have a few comments. One 6 is with respect to PRHR. I think we have been discussing 7 it for the last several meetings. I find no scale test 8 facilities have been fabricated under the conditions 9 expected to be encountered prototype.
10 Also, I think PRHR is a C tube heat exchanget.
11 Separate tests have been done only with three vertical in-12 line tubes. In a large scale facility such as SPES and 13 OSU, the flow conditions are very different than those
,,3 14 would be enccuntered in a prototype. I think this meeting 15 or tomorrow they should address PRHR here.
16 The other area which I did not see much ;
l 17 discussion in the report is the what insights we'll gain 18 from separate tests and integral tests, and how these i
19 insights were reflected into the regional PIRT. !
l l
20 Computer codes results can not be used to 21 alter the importance of various phenomena. It should come 1
22 from the experiments. )
l 23 Also, I find in the report most of the l 24 analysis, especially where the equations are normalized, g s,
(,) 25 is done under the assumption that there's only single loop 1
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l 1 that is dominant. In reality, there were many loops j g 2 interacting. I would like to see some discussion as to l
O 3 why only one loop was chosen and how the interactions were l
i 1 1 4 ignored.
l 5 CHAIRMAN CATTON: Mario?
6 MEMBER FONTANA: Pass.
7 CHAIRMAN CATTON: Bob?
8 MEMBER SEALE: Well, the only question I have 9 is what is it about the Yankee metabolism that requires it j 10 to be 85 degrees in rooms after the first of November. j 11 CHAIRMAN CATTON: It actually is a thermal I
I 12 hydraulic problem. What it is, it's this extreme effort 13 they go to on the east coast to make sure that the average
?
V 14 temperature stays the same year round.
15 Tom, do you have any comments?
16 MEMBER KRESS: No. You have covered it pretty ;
17 well.
18 CHAIRMAN CATTON: George? First, we're going 19 to hear from Alan Levir of NRR.
20 MR. HOCHREITER: Ivan, before we get started, 21 could we get a copy of your written comments?
22 MEMBER KRESS: You went a little fast. I 23 missed a few.
l j 24 CHAIRMAN CATTON: Yes. It would probably a
,a I (j 25 good idea to give them to you right now. Then you could !
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10 1 send part of your team out to get the answers
,g 2 MR. HOCHREITER: Well, they may not come back.
]
3 MR. LEVIN: My name is Alan Levin. I am 4 currently Acting Section Chief in the Reactor Systems 5 Branch in the Office of Nuclear Reactor Regulation.
6 I'll take a few minutes this morning to talk 7 about what the staff's objectives were in asking 8 Westinghouse for this report. Westinghouse will then go 9 through in detail the information that they presented in 10 the report. I will wrap it up at the end with our initial 11 review comments.
12 I thought that it would be useful to go back 13 and talk a little bit about what we have been doing- here.
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14 This is both for the benefit of the Committee members, 15 Subcommittee members, and the consultants, that may not 16 have been here when this all started in late 1990 or so.
l 17 Also just to put us all on the same page in terms of how 18 the review has progressed to this point.
19 We started a detailed review of the AP600 20 testing program around 1990. Not coinci dently, that's 21 about the time that I joined the staff. There had been 22 some preliminary discussions with Westinghouse early in i 23 1990, but we really g*. down to business on in depth L
24 review late in that year.
(,/ 25 In mid-1991, we released SECY-91-273 which had NEAL R. GROSS COURT REPORTERS A.ND TRANSCRIBERS 1323 RHODE ISLAND AVE., N W.
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l 11 l
l 1 a dual purpose. The purpose of the SECY paper itself was l
l r s 2 te establish the overall process for the test program i ( 1 1 G/
3 review. We told the world, primarily the vendors, how we 4 were going to proceed step by step through evaluation of 1
5 their testing programs.
6 As an appendix to SECY 91-273, we also 7 included an initial evaluation of Westinghouse's test 8 program at that stage. The only thing that wasn't covered 9 explicitly in that initial evaluation was large scale high 10 pressure integral test.
11 It was determined around the same time that 12 the SECY paper was produced that the test program was 13 deficient in that it did not include a high pressure
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(--) 14 integral test and we worked for about the next several 15 months as Dr. Catton I'm sure recalls, trying to persuade 16 Westinghouse and the ACRS that the staff's view on this 17 was appropriate.
18 We did come out with a SECY paper,92-030. Is 19 this microphone working?
20 CHAIRMAN CATTON: There's something wrong with 21 it.
22 MR. LEVIN: We released SECY 92-030 in early 23 calendar year 1992, continued to discuss with Westinghouse l 24 the options for doing high pressure integral testing. In
^
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12 1 appropriately modified.
g~s. 2 Westinghouse began to submit detailed L-)
3 information on their test programs in 1991, continuing 4 through 1994. This included facility designs, their 5 PIRTs, scaling analyses, and the test matrices.
6 We were in sort of a continuous review mode on 7 these things. We provided a number of comments back to 8 Westinghouse more or less continuously on the adequacy in 9 our view of some of the test facility designs and the test 10 matrices, and the scaling reports as well.
11 But we did see some designs in the test 12 facilities to reflect changes in the AP600 design and/or 13 to reflect a better simulation of what we expect are the
)
- 14 important phenomena to be.
15 Most of the design certification testing was )
16 performed during calendar year 1994. The PRHR program, as 17 you know, was run before we even got into this review mode 1
18 in the late 1980s. But the automatic depressurization 19 system tests, CMT tests, Oregon State University, reduced 20 scale integral systems tests and SPES-2 were all done in l
21 that same calendar year.
22 Our activities during the time that the tests l 1
l 23 were actually performed were observation of the tests. We 24 visited all of the test facilities and watched tests in
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, (m) 25 progress, and a review of preliminary results.
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13 l' The staff issued the AP600 draft safety fg 2 evaluation report in November 1994, which reflected our t i
.)
3 findings on materials submitted through about the middle 4 of that year.
5 The beginning of the last phase of test 6 related information, which were the data reports and the 7 test analysis reports for these four test programs, were 8 provided between --
9 CRAIRMAN CATTON: Of which?
10 MR. LEVIN: Yes, I gave a stack to Paul.
11 This occurred between December 1994, I think 12 the first one that came in was CMT, and September of 1995, 13 which was the last of the OSU test reports.
5/ 14 The review of the CMT and SPES tests were 15 closed out in the supplemental DSER that was issued in 16 April of 1996. The review of the ADS and OSU programs are 17 considered to be complete except for resolution of 18 outstanding RAIs.
19 Let me elucidate on this just a little bit.
20 The review of the test programs and review of the codes 21 are obviously linked closely together. But the two are
, 22 being carried out as separate activities. The review of l
l 23 the test programs really is aimed at answering the 24 question, were the test facilities scaled properly, were
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14 1 valid data, and can they be used to perform the validation ew 2 of the AP600 computer codes. That's really where the test 7
b 3 review per se stops.
4 The test review does not go into whether the 5 codes are any good. That is Westinghouse's job, to prove 6 once we had determined that the data are okay.
7 So when I say that the review of the SPES-2 8 and CMT test programs are closed, it means that we came to 9 the conclusion, and these were closed pending review of l
10 the PIRT scaling and closure report, if any new issues 11 were raised, i 12 But when we say it was closed, it means we i
13 determined that to our satisfaction, those questions about I
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-' 14 the test program had been satisfactorily addressed, that 15 we thought that the data were acceptable for code j 16 validation, that Westinghouse had resolved open issues 17 with regard to the unexpected phenomena and scaling 18 distortions and that sort of thing. And that at that 19 point, it was appropriate to go on and start looking at 20 the codes.
21 So I do want to keep that perspective here as 22 we talk about the test review, because we really are not 23 talking about the code review in any kind of detail at all 24 here.
rm k_) 25 The passive RHR review is still continuing.
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15 l 1 We received a revision of the final test report about a l
g3 2 month or so ago. This was done to correct an error in the
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3 original data conversion program going from electronic ;
4 data to engineering units, which had an impact on the 5 results of the test program. We're in the middle of that 6 right now.
7 The staff requested that Westinghouse provide 8 this closure document about a year ago. We received it in 9 September of 1996. l 10 I also want to mention that the NRC has 11 conducted an extensive confirmatory program in parallel ]
12 with Westinghouse's efforts. Beginning around 1990, we i
13 started doing analyses with RELAP as with some initial l
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14 modifications to account for the new design aspects of the 15 AP600. The code obviously had not been validated for the 16 AP600 at that point. However, we did. get some very l
17 interesting insights I think, out of those initial 18 analyses in terms of system based phenomena, system based 19 behavior, which helped to inform our subsequent review of l 20 the test programs.
I 21 There was also a parallel PIRT' development 22 effort, which I think has been very well done and very 23 successful. It has also provided a good basis on which to 24 evaluate Westinghouse's PIRTs. Testing in the ROSA and
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16 1 now. There are still tests planned at OSU and tests
(~S 2 planned at ROSA, primarily in the beyond design basis
, (al 3 areas.
4 There's also a parallel scaling evaluation 5 activity that has been performed. The results, j l
6 preliminary resulta have just come out on that as well. l 7 We are taking a look at those.
8 So what are our objectives, staff objectives 1
1 9 for this report? Well, Westinghouse has developed a i
l 10 series of PIRTs for AP600 accidents and transients, and 11 has done detailed scaling analyses for the CMT, OSU and 12 SPES facilities.
13 The analysis of the test results are
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14 documented in a test analysis report. So there's a whole 15 shelf-full of reports sitting out there with a great deal 16 of information in them. One of the major objectives here 17 was to get significant results from these related 18 activities into one report to address the relationship 19 between them with a focus on the big picture.
20 The specific objectives, I have identified 21 four of them here. A review of facilities scaling on a 22 consistent basis. The scaling analyses were done at 23 different times by different people. They were not all l
24 done initially using the same sort of methodology. So
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, (_,/ 25 here is an opportunity to go back to a more or less i
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17 1 uniform methodology and do a last take, a last evaluation r~Ni 2 on that consistent basis to see whether scaling was done e
V 3 properly and to address issues that had been raised over 4 the years by the staff and by the ACRS, things like 5 momentum equation scaling and the top-down integral 6 approach that Wolfgang Wulff had developed.
7 Another one is possible re-ranking of l
8 phenomenon validation of the PIRTs. By validation of the ;
i 9 PIRTs, what I mean is demonstration that the test results 1
10 are consistent with the expert elicitation rankings that 11 are contained in the PIRT.
12 The Office of Research has done a similar l 13 activity. They call this rePIRTing. I think that's 7_
- 8
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14 probably as good a terminology as anything.
15 MEMBER KRESS: Alan, what would you do if such 16 an exercise markedly changed your idea of the ranking of 17 phenomena?
18 MR. LEVIN: I think that has to be reflected 19 in the way that you consider the -epresentation of 20 phenomena in the computer codes. One of the things that 21 we look at that I think is useful is that the PIRT really 22 provides a linkage between the computer codes and the test l
l 23 programs. That high ranked phenomena, important phenomena 24 in the PIRT should be represented in the codes to the best
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l 18 1 1 a relatively small degree of uncertainty.
1
,q 2 Again, this is ideal situation. Recognize tu-) .
l 3 that. It may not be possible to do that point by point 4 down the line, but those are the areas of focus.
5 If things came up really really different, I 6 mean just totally turned our expectations --
7 MEMBER KRESS: You would have to go back and 8 re-think your PIRT.
9 MR. LEVIN: Yes. You would have to go back 10 and rethink your PIRT. Yc,a would have to go back and 11 rethink your test program to make sure that you covered 12 off everything appropriately. You know, one of the things ,
13 here is to look at insights and see whether you have
/,_S
'-- 14 covered off all of the phenomena that you think are going 15 to be present at the AP600. If the test program were to 16 show that there are major phenomena having a significant 17 impact on system response that you hadn't thought were l
18 there or important to begin with, then clearly you have to 1 19 go back and look at your test program and see whether you 20 have covered everything.
21 CHAIRMAN CATTON: And a good example of that 22 is the thermal stratification. The first PIRT did not 23 mention it.
24 MR. LEVIN: That's right. But I think you have to look at that sort of an issue, when we know the h(3 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE '.SLAND AVE., N W.
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1 19 l 1 codes, a code like NOTRUMP, for instance is not going to )
,3 2 be able to represent single phase stratification. So you e ;
/
3 have to go and look and see whether that looks like it's 4 important in terms of a system response, and if it is, do 5 you understand at least on a qualitative basis, how it 6 might influence it if you can't model it very well.
l 7 So there's a number of different aspects that 8 flow into this. It's not all quantitative evaluation 9 using the codes. You have to make some engineering 10 judgements as well. I 11 The last two objectives are the 12 identification, discussion of unexpected phenomena, 13 unexpected loop behavior, their physical mechanisms, and t\ ') 14 the applicability to the AP600 plant. This is what you 15 just mentioned.
16 This is important. We clearly in some of the 17 test programs saw unexpected phenomena. In some cases, we 18 have come to the conclusion, we and Westinghouse both have 19 come to the conclusion, that those phenomena or system 20 responses were a distortion related to the facility 21 design, and probably wouldn't be expected in the AP600.
22 In some cases, the opposite is true. That the l
23 mechanism seemed to be based on the same characteristics 24 between the test facility and the plant, and that we might
,O
() 25 very well expect to see similar phenomena in the plant.
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20 1 The last objective is the identification and
,f g 2 discussion of scaling related distortions, effects on test
\
v) 3 loop response, relation to AP600 analysis. This includes 4 consideration of phenomena not represented in the tests 5 and/or not modeled in the codes. Thermal stratification 6 is in fact one of those.
7 So these are some of the key points that we 8 are looking at in terms of the review of the scalicg and 9 PIRT closure report.
10 CHAIRMAN CATTON: You know, this seems to me, 11 the thermal stratification and the CMT, this would be a 12 good case for use of the separate effects tests. Are they 13 doing that, do you know?
( n
\-' 14 MR. LEVIN: I'll let Westinghouse --
15 MR. HOCHREITER: Yes. We have analyzed the 16 CMT separate effects test with NOTRUMP. J l
17 CHAIRMAN CATTON: Okay. l I
18 MR. HOCHREITER: We submitted a preliminary l 1
19 validation report on that. In fact, two preliminary 20 validation reports on those. We have completed the 21 analysis for the final validation report which was issued 22 yesterday.
l 23 MR. ZUBER: We just heard that NOTRUMP can not 24 calculate that phenomena, so how can you validate it?
A
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21 1 want to be misunderstood. What NOTRUMP can't represent is es 2 thermal stratification in pipes like in the hot leg and i
V I was not referring to CMT.
3 the cold leg.
4 CHAIRMAN CATTON: And it can't really do it in 5 the CMT either. My understanding of what they have said, 6 they can do things to accommodate the phenomena. Anyway, 7 hopefully we're going to hear a little bit about that.
8 MR. LEVIN: Well --
9 CHAIRMAN CATTON: You don't really calculate 10 the stratification other than what is -- just you have a 11 chunk of hot fluid sliding down the top of the CMT. You 12 don't actually calculate the boundary layers and the 13 mixing and the development of the thermal stratification.
rh
\] 14 MR. HOCHREITER: Unfortunately we calculate 15 too much mixing.
16 CHAIRMAN CATTON: I understand that. That's 17 typically the problem with these kind of codes because l l
18 they don't deal with it appropriately.
19 On the other hand, you have separate effects l
20 test data, so that should enable you to put together a 21 transfer function that you can use in the code.
I 22 MR. HOCHREITER: I have got some stuff on that i 23 that I can show you. l 24 MR. LEVIN: But again, I want to go back to (3
C) 25 what I said earlier.
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l 22 1 CHAIRMAN CATTON: I didn't mean to get into i r~s 2 that discussion.
(v !
3 MR. LEVIN: I know. I know. But this is an 4 important point to look at I think down the line. The 5 test program, the CMT test program, clearly did represent 6 the sorts of thermal stratification that you might expect 7 to see in the plant. You can argue some of the finer 8 points like the multi-dimensionality and so forth because 9 of the size of the thing relative to the full-scale CMT, 10 but at least on a one-dimensional basis, the 11 stratification was represented in the test facility. I 12 think that is where we want to focus the discussion here.
7s 13 Once we can close out the review of the test
( )
'~^ 14 program as such, then you can go on and look at the 15 details of the code evaluation.
16 Now we're not finished with NOTRUMP. The 17 reviewer is sitting in the back here. These kinds of 18 issues are going to be taken up as part of the resolution 19 of the code reviews.
20 CHAIRMAN CATTON: The only reason I mentioned 21 it now is because this is a good example of how the 22 separate effects testing should be used, to address this
( 23 kind of an issue.
24 MR. LEVIN: I agree.
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l 23 l . .
1 that in the PIRT scaling document, they treated it as a l ,e m 2 one-dimensional problem, so the aspect ratio did not i NJ' 3 surface anywhere. As a matter of fact, I didn't find any i
4 mention of it. Maybe we'll comment on this later, get to i 5 the CMT.
1 6 When you suspect multi-dimensional behavior, 7 you really should look at multi-dimensional behavior. You 8 won't find it if you look at one-dimensional behavior.
9 MR. LEVIN: That's correct, but I think you 10 have to evaluate the relative magnitude of the influence 11 of the multi-dimensional aspects.
1 12 CHAIRMAN CATTON: Absolutely. But you can't 13 do that looking at one-dimensional equations.
S
'- 14 MR. LEVIN: That's true enough.
I 15 CHAIRMAN CATTON: That is what they have done. ;
l 16 At least that is what they have reported. i l
17 MR. ZUBER: I have a question. You didn't 18 finish the review of this report.
i 19 MR. LEVIN: We have not finished the review.
20 That's correct.
21 MR. ZUBER: Okay now, can you comment on these 22 objectives, did they meet them, and to what degree did 23 they meet them.
l 24 Let me say why, because that letter which was l p l
V 25 written December 10 by Zibroski --
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24 1 MR. LEVIN: Well, I wrote it, but he sent it.
l
,e~ 2 I wrote it.
\m / )
3 MR. ZUBER: Okay. Wait, wait, wait. The j 4 thing is, I was just going to say it's a very good letter.
5 MR. LEVIN: Thank you.
6 MR. ZUBER: Many comments which I completely 7 agree. Actually, what really I didn't want to make this j 8 comment in the beginning. What is really saddening to me l 1
l 9 and disturbing is that some of these aggressions were 10 brought over years, at least since 1991. Really you bring 11 them again here. They are really not addressed in this 12 report.
13 I think those are very good questions you have t
)
14 here. I would really like to hear Westinghouse since they 15 had this letter at least for nine days or whatever, to 16 address them.
17 For example, the scaling isn't consistent but 18 you have really done over by several people over several 19 years, and you have a mumbo jumbo. You put it together.
20 It's inconsistent. I think this was brought in this 21 letter too.
22 There are other comments which you didn't l
23 bring it here. There is no comparison with experimental 24 data, on the dimensional form. This is something which we
< p/
t, 25 are learning through fluid dynamics. Here we pretend to i
NEAL R. GROSS l COURT REPORTERS AND TRANSCRIBERS i
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25 1 scale and we don't demonstrate scaling by the most r~s 2 rudimentary elementary way how to do it.
t i
%/
3 Let me just summarize. It was a good, good 4 questions. I would hope that some of these are addressed 5 in the presentation by Westinghouse.
6 MR. LEVIN: Well since I haven't heard 7 Westinghouse's presentation, I am going to hope so too.
8 Let me, if I can, defer my answer to your 9 question until tomorrow when I make my wrap up 10 presentation because I don't want to jump ahead with 11 conclusions in advance of what Westinghouse is going to 12 present here. The closing presentation tomorrow afternoon 13 really does to some extent address our views of where we
/ T Y2 14 are relative to these kinds of questions.
15 MR. ZUBER: Mr. Chairman, this is exactly what 16 I will do tomorrow. I didn't want to address them in the 17 beginning, I have got tomorrow afternoon. But let me say, 18 this was --
19 CHAIRMAN CATTON: It will give you some time 20 to change them depending on what Westinghouse says.
21 MR. ZUBER: That's right. I mean to see how 22 they think. But those were very good comments.
23 MR. LEVIN: Thank you. I can't take complete 24 credit. I had a lot of help from some very good
(*
25 contractors.
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1 26 I 1 CHAIRMAN CATTON: It's not often he says good )
('] 2 things. I think just move on.
(/]
3 MR. LEVIN: Well I like to give credit where 4 credit is due.
5 MR. ZUBER: Same here.
6 CHAIRMAN CATTON: You don't have to bow. J 7 MR. LEVIN: No. I'm sure, take the good with l
8 the bad.
l 9 That concludes my initial comments unless 10 there are any further questions. l l
11 CHAIRMAN CATTON: No, and I look forward to j 12 hearing what you have to say tomorrow. i 1
13 MR. BCEHNERT: We have to go into closed
( i
'"' 14 session now. l 15 CHAIRMAN CATTOIJ: We now have to go into l
l 16 closed session. I assume Westinghouse will take care of l
17 kicking those out who should go out.
18 (Whereupon, at 9:12 a.m. the open session was 19 concluded.)
20 21 22 23 24
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l J<
i 1 *
!O CERTIFICATE
\
! This is to certify that the attached l i
j proceedings before the United States Nuclear i
] Regulatory Commission in the matter of: l 4
! Name of Proceeding: ACRS SUBCOMMITTEE ON THERMAL HYDRAULIC PHENOMENA
! Docket Number: N/A I
j Place of Proceeding: ROCKVILLE, MARYLAND i were held as herein appears, and that this is the original j
j transcript thereof for the file of the United States Nuclear Regulatory Commission taken by me and, thereafter reduced to I typewriting by me or under the direction of the court j reporting company, and that the transcript is a true and l accurate record of the foregoing proceedings.
4 eflA l Q ORBETT RIN8R l
! Official Reporter j Neal R. Gross and Co., Inc.
i h
I k
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j
J.
(~
(g INTRODUCTORY STATEMENT BY THE CHAIRMAN OF THE
/ THERMAL HYDRAULIC PHENOMENA SUBCOMMITTEE 11545 ROCKVILLE PIKE, ROOM T-2B3 ROCKVILLE, MARYLAND DECEMBER 18-19, 1996
. The meeting will now come to order. This is a meeting of the ACRS Subcommittee on Thermal Hydraulic Phenomena.
I am Ivan Catton, Chairman of the Subcommittee.
The ACRS Members in attendance are:
Mario Fontana, Tom Kress, and Robert Seale. ACRS Consultants in ;
attendance are "V.J." Dhir, Virgil Schrock, and Novak Zuber.
We also have in attendance Dr. S. George Bankoff who is observing this meeting on behalf of the Office of Nuclear Regulatory Research's Nuclear Safety Research Review Committee.
The purpose of this meeting is to review the Westinghouse Scaling and PIRT Closure Report (WCAP- 14 727) that addresses the relevant issues associated with the AP600 reactor coolant system. The Subcommittee will gather informaticn, analyze relevant issues and facts, and formulate proposed positions and actions as appropriate,
/) for deliberation by the full Committee.
V Most of this meeting will be closed to the public to protect information deemed proprietary to the Westinghouse Electric Corporation.
Paul Boehnert is the Cognizant ACRS Staff Engineer for this meeting.
The rules for participation in today's meeting have been announced as part of the notice of this meeting previously published in the Federal Register on November 27, 1996.
4 A transcript of the meeting is being kept and will be made available as stated in the Federal Register Notice. It is requested that the speakers first identify themselves and speak with sufficient clarity and volume so that they can be readily heard.
We have received no written comments or requests for time to make oral statements from members of the public.
(Chairman's Comments-if any)
(
xm ,/ We will proceed with the meeting and I call upon Dr. Alan Levin of NRC's Office of Nuclear Reactor Regulation to begin.
~
O O "O .
NRR STAFF PRESENTATION TO THE ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
SUBJECT:
STAFF OBJECTIVES FOR AP600 SCALING AND PlRT CLOSURE REPORT DATE: DECEMBER 18,1996 PRESENTER: ALAN E. LEVIN PRESENTER'S TITLE: ACTING SECTION CHIEF SPECIAL PROJECTS ADVANCED REACTOR SYSTEMS SECTION REACTOR SYSTEMS BRANCH DIVISION OF SYSTEMS SAFETY AND ANALYSIS OFFICE OF NUCLEAR REACTOR REGULATION PRESENTER'S TEL. NO.: (301) 415-2890
BACKGROUND AND HISTORICAL PERSPECTIVE STAFF'S REVIEW OF AP600 TESTING PROGRAM BEGAN IN 1990 SECY-91-273 ESTABLISHED PROCESS FOR TEST PROGRAM REVIEWS AND CONTAINED INITIAL EVALUATION OF AP600 TEST PROGRAM i
i t
STAFF " WHITE PAPER" ON HIGH-PRESSURE INTEGRAL TESTING PREPARED IN MAY 1991; j LAID GROUNDWORK FOR SECY-92-030 ON NEED FOR TESTING WESTINGHOUSE AGREED (MARCH 1992) TO PEFORM TESTS IN SPES-2 FACILITY i
MATERIAL ON TEST FACILITIES' DESIGNS, PIRTS, SCALING, AND TEST PROGRAMS !
PROVIDED TO STAFF FROM 1991 TO 1994 l l
STAFF PROVIDED COMMENTS TO WESTINGHOUSE RESULTING IN CHANGES IN !
DESIGNS AND TEST MATRICES ,
l MOST DESIGN CERTIFICATION TESTING WAS PERFORMED DURING CY 1994 (ADS, CMT, OSU, SPES-2) !
STAFF ACTIVITIES: OBSERVATION OF SELECTED TESTS AND REVIEW OF I PRELIMINARY RESULTS l
AP600 DSER ISSUED IN NOVEMBER 1994, REFLECTING STAFF FINDINGC .~tlR O U G H MID-1994 l 4
i i
[
Il
BACKGROUND AND HISTORICAL PERSPECTIVE (cont'd)
FINAL DATA REPORTS AND TEST ANALYSIS REPORTS PROVIDED BETWEEN DECEMBER 1994 AND SEPTEMBER 1995 REVIEW OF CMT AND SPES-2 TESTS CLOSED OUT IN SUPPLEMENTAL DSER (APRIL 1996); REVIEW OF ADS AND OSU PROGRAMS COMPLETE EXCEPT FOR RESOLUTION OF OUTSTANDING RAls PRHR REVIEW ONGOING DUE TO REVISION OF FINAL TEST REPORT TO CORRECT ERROR IN ORIGINAL DATA CONVERSION STAFF REQUESTED THAT WESTINGHOUSE PROVIDE " CLOSURE" DOCUMENT ABOUT ONE YEAR AGO SCALING AND PIRT CLOSURE REPORT SUBMITTED FOR STAFF REVIEW IN SEPTEMBER 1996 i
NRC HAS CONDUCTED EXTENSIVE CONFIRMATORY PROGRAM IN PARALLEL WITH
- WESTINGHOUSE'S EFFORTS ACTVITIES INCLUDE ANALYSES (BEGINNING CA.1990); PIRT DEVELOPMENT (ALSO CA.
l 1990) TESTING IN ROSA /LSTF AND OSU FACILITIES (1993 - PRESENT); AND SCALING ANALYSES OF INTEGRAL FACILITIES
- 7 7; O O O
- NRC OBJECTIVES FOR SCALING AND PlRT CLOSURE REPORT WESTINGHOUSE HAS DEVELOPED PIRTs FOR AP600 ACCIDENTS AND TRANSIENTS DETAILED SCALING ANALYSES DEVELOPEG FOR CMT, OSU, AND SPES-2 FACILITIES i ANALYSIS OF TEST RESULTS DOCUMENTED IN DATA AND TEST ANALYSIS REPORTS STAFF REQUESTED A SINGLE " CLOSURE" DOCUMENT TO PULL TOGETHER SIGNIFICANT PIRT/ SCALING / TESTING RESULTS IN A UNIFIED FORM, WITH FOCUS ON " BIG PICTURE" SPECIFIC OBJECTIVES:
REVIEW OF FACILITY SCALING ON A CONSISTENT BASIS, ADDRESSING ISSUES RAISED BY STAFF AND ACRS te.g., MOMENTUM EQUATION, TOP-DOWN APPROACH) I POSSIBLE RERANKING OF PHENOMENA AND " VALIDATION" OF PIRTs, i.e., ;
DEMONSTRATION THAT THE TEST RESULTS ARE CONSISTENT WflH IDENTIFIED i PHENOMENA AND EVALUATION OF THElR IMPORTANCE lDENTIFICATION AND DISCUSSION OF UNEXPECTED PHENOMENA / LOOP BEHAVIOR-PHYSICAL MECHANISMS AND APPLICABILITY TO AP600 PLANT IDENTIFICATION AND DISCUSSION OF SCALING-RELATED DISTORTIONS, EFFECTS ON i TEST LOOP RESPONSE, RELATION TO AP600 ANALYSIS; INCLUDES CONSIDERATION !
OF PHENOMENA NOT REPRESENTED IN TESTS AND/OR NOT MODELED IN .
ANALYTICAL CODES (e.g., THERMAL STRATIFICATION) i t
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