ML20246P537
| ML20246P537 | |
| Person / Time | |
|---|---|
| Issue date: | 07/13/1989 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| ACRS-T-1749, NUDOCS 8907200240 | |
| Download: ML20246P537 (265) | |
Text
- _-
A &J7 /rfV ,
o B 3 \'A _
UNITED STATES !
NUCLEAR REGULATORY COMMISSION l
...-------------------------=========---------r==========---.
i ADVISORY COMMITTEE ON REACTOR SAFEGUARDS In the Matter of: )
)
)
351st ACRS Meeting )
Day One )
O Pages: 1 through 187 Place: Bethesda, Maryland Date: July 13, 1989 g ACRSOff, n c:abra*m
. ........-............. qg. $,;.3 g. g g ..,.g...[g.,A!i.3----
J . ,. .
f i
HERITAGE REPORTING CORPORATION ,
OgiledalReporters O 1220 L Street, N.W., Suke 640 Washington D.C. 20005 (202) 628-4388 8907200240 090713 ;
PDR ACHS T-1749 PNU J
3 1- PUBLIC NOTICE BY THE 2 UNITED STATES MUCLEAR REGULATORY COMMISSION'S 3 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
'4 July 13, 1989 5-6 7 The contents of this stenographic transcript of 8- the proceedings of the United States Nuclear Regulatory 9 Commission's Advisory Committee on Reactor Safeguards 10 (ACRS), as reported herein, is an uncorrected record of the 11 discussions recorded at the meeting held on the above date.
12 No membeb of the ACRS staff and no participant at 13 this meeting accepts any responsibility for errors or 14 inaccuracies of statement or data contained in this 15 transcript.
16 17 18 19 20 21 22 23 24 25 Heritage Reporting Corporation (202) 628-4888 l
g- ,
'l ie k ' UNITED STATES NUCLEAR REGULATORY COMMISSION.
p ADVISORY COMMITTEE ON REACTOR SAFEGUARDS In'the'. Matter of:, )
)
)
351st ACRS Meeting ~ )
Day One )
Thursday,
' July 13, 1989 r Room P-110, Phillips Building 7920 Norfolk Avenue' Bether,da, Maryland The meeting convened, pursuant-to notice, at.8:30 a.m.
BEFORE: DR. FORREST J. REMICK Chairman, ACRS Associate Vice-President.for Research Professor of Nuclear-Engineering C];
/
The Pennsylvania State. University University Park, Pennsylvania ACRS MEMBERS PRESENT:
DR. WILLIAM KERR-Professor of Nuclear Engineering Director, Office of Energy Research University of Michigan Ann Arbor, Michigan MR. CHARLES J. WYLIE Retired Chief Engineer Electrical Division Duke Power Company Charlotte, North Carolina DR. PAUL G. SHEWMON Professor, Metallurgical Engineering Department Ohio State University Columbus, Ohio i Heritage Reporting Corporation (202) 628-4888
2-ACRS MEMBERS PRESENT (Continued)*
DR. CHESTER P. SIESS Professor Emeritus of' Civil Engineering University of Illinois Urbana,' Illinois.
MR. DAVID A. WARD.
Research Manager on Special Assignment-E.I. du Pont de Nemours & Company Savannah River Laboratory.
Aiken, South Carolina DR.. HAROLD W.. LEWIS Professor of Physics Department of Physics University of Califo.;nia Santa Barbara, California MR. CARLYLE MICHELSON Retired Principal Nuclear Engineer Tennessee Valley Authority' Knoxville, Tennessee, and Retired Director, Office for Analysis and Evaluation of Operational Data
.U.S. Nuclear Regulatory Commission Washington,'D.C.
MR. JAMES CARROLL Retired. Manager, Nuclear Operations Support Pacific Gas & Electric Company San Francisco, California DR. IVAN CATTON Professor of Engineering Department af Mechanical, Aerospace & Nuclear Engineerir. g School of Engineering and' Applied Sci 9nce University of California Los Angeles, California ACRS COGNIZANT STAFF ME 6 :
RAYMOND FRALEY, Executive Director, ACRS Beritage Reporting Corporation (202) 628-4888
____________J
3' 1 EBQGEERI.HGE 2 DR. REMICK: We will now come to order.
3 Again, I will try to turn to the first agenda 4 item, USI-30 seismic design criteria. And Chet Siess is our 5 subcommittee chairman.
6 Chet; 7 DR. SIES3: We had a subcommittee meeting on this-8 a couple of weeks ego and had a fairly complete report from 9 the Staff. We have asked them to come in this morning and 10 give the Full Committee a portion of that report, pretty 11 much the chronology of the resolution of this issue and 12 proposals.
13 This was originally called the -- there were two 14 USIs on seismic: there was a short-term program A-40; and a bOh 15 long-term program A-41. And the name of this one got 16 changed.
17 Since it started in 1977, I don't know at what 18 point in time they realized it wasn't really very short-term 19 and it was changed to simply " seismic design criteria."
20 But Mr. Shaukat w311 give us an outline of what 21 they went through and what they came up with. I'll just 22 turn it over to him, it's really straightforward.
23 (Slides being shown.)
40 MR. SHAUKAT: My name is Khalic Shaukat, I am the 25 test manager on the USI A-40. I will present the chronology
() Heritage Reporting (202) 628-4888 Corporation 4
_=_- _ - ]
4 c/'N 1' of'USI'A-40 and the resolution of it.
^ 7(;/
1 2 'A-40. originated in 1977 with the following 3 objectives: investigate the selected areas'of seismic design 4 sequence and quantify margins, if any, in the design 5 process.
6 And modify the criteria, review criteria in the 7 standard review plan if changes are found to be justified.
8 Our contractor Lawrence Livermore completed the 9 study and published a report NUREG/CR-1161 in May 1980,.
10 summarizing all the technical studies done by various 11 contractors on this A-40 seismic design criteria and various 12 plans under A-40.
13 ' Lawrence Livermore also developed conclusions from 14 the technical studies and made specific recommendations for 15- SRP changes.
16 NRR Staff then completed review of NUREG-1161 and 17 developed the Staff position for each recommendation. And 18 these positions were to be included in the SRP or the 19 revised portion of the SRP.
20 The Staff review of Lawrence Livermore 21 recommendations resulted in additional tech;._ al work, and 22 that was done in the time frame of 1983 to '85.
23 The minimum requirement for power spectral density
,24 was developed as a secondary check for use of single time 25 history. This was a Lawrence Livermore recommendation that
. I~h Heritage Reporting Corporation
\" (202) 628-4888
5 1
()
1 some criteria should be developed to justify the use of i
2 single time history and the development of PFD criteria of ]
I l 3 power spectral density criteria is just a secand recheck for ;
1 i
4 that concern. j I
5 The Staff current practice needed to be reflected 6 in the SRP also and those pertained to this SRP 2.52 and 7 those have been also included.
8 Above ground steel tanks were a concern under 9 earthquake loading. And Los Alamos made a study and it was 10 documented in NUREG-4776. And this helped in establishing 11 some guidelines.
12 The Staff has some disagreement in one area of 13 recommendations by Livermore and that is soil-structure 14 interaction. And a workshop was held in June 1986 sponsored r^]s
\-
15 by BNL and NRC to come up with certain Staff position. This 16 workshop focused on USI A-40 proposed changes. It has beea 17 attended widely by experts in the industry, by researchers, 18 international -- from other countries.
19 This workshop provided expert consensus on current 20 soil-structure interaction and it has been documented in 21 NUREG/CP-0054, 22 Another workshop was held in December 1987 23 sponsored by EPRI, NRC, and Taiwan Power Company. And this 24 considered -- this workshop considered results of LOTUNG 25 experim(nt in Taiwan for actual recorded earthquakes, forced
/~
\}' Heritage Reporting Corporation (202) 628-4888
ll .i 6-
.(f l'- vibration tests on scale model.
2' DR. KERR: After the Staff's disagreement with LNL-3 and the subsequent studies, was the Staff able to convince 4 _LNL that the Staff was. correct or did it attempt.to convince 5 LNL7 6 MR. SHAUKAT: Yes, we did attempt to convince them 7 that the position we developed after the two workshops had 8 been sent out for public comments and they had a chance to 9 comment on it. And our final position, in fact, came very 10 close to their initial prqposed position.
11 DR.. KERR: So they convinced you that they were 12 right or you convinced --
13 MR. SHAUKAT: They convinced partly that they were 14 right:and we are using their initial recommendations.
15 DR. KERR: Thank you.
16 MR. SHAUKAT: In the process of developing that 17 position for our soil-structure interaction the Staff 18 proposed to incorporate the results in A-40 by soliciting
- 19. some comments and answers on specific questions during 20 public comment. The public commented on those questions and 21' the answer to those questions have arrived at a final 22 ' position on soil-structure interaction.
23 MR. CARROLL: Could you comment a little further 24 on the Taiwan experiments, what were the nature of these?
25 MR. SHAUKAT: The scale models located in Taiwan Heritage Reporting Corporat.on (202) 628-4888
7 1- where in a' period of two years' actual' recordings of the, 2 earthquakes that occurred-in a period of two years had been 3 ;made, And the. instruments have been located at various 4 locations of the scale.model at the foundation level, at 5 some high elevation, and the measurements have been made.
6 And after that analysis by'various methods of 7 soil-structure. interaction have been performed to correlate 8 those of.the analysis with the scale model tests, 9 . recordings.
10 And the results showed that there were --
11 actually, the predictions by the calculations were.not 12 really in quite close agreement. So they started'looking 13' what is th'e deficiency in our design process or analysis 14 process that the prediction is not very close.to_the actual
- {)
15 earthquake recording ~ data.
16- And they found that there were some deficiencies 17 in the analysis. For~ example, the' connections were assumed' 18 to be rigid, but they were not fully rigid and required a-19 different response.
20 Anything more, Goutam Bagchi, you want to add? l 21 FGl. BAGCHI: Well, it really is a very, very 22 impressive experiment. Large magnitude earthquakes occurred 23 there. Instrument was -- dense instrumentation, in-depth !
24 erays were placed. And now they have even full water 25- pressure monitoring system.
Heritage Reporting Corporation
.( ) (202) 628-4888 1
8 k.)3 1 And it's really a unique opportunity for everybody 2 to test their analytical method. This is the first time 3 something like that had been done.
4 And like Khalid pointed out, there were some 5 deficiencies in the assumption of in-conditions. There are 6 some problems with respect to the damping of the soil 7 material and things like that. Shear modulus was considered 8 to be softer than what was actually the case.
9 And basically, analytical methods were verified by 10 this process. It's really one of the most unique 11 experiments that one could think of. The scales were large 12 scale models.
13 MR. CARROLL: When you say " scale models," what 14 sort of scaling are you talking about? I (J3 15 MR. SHAUKAT: One-thirtieth and one-quarter scale; 16 two scale models they used.
17 Continuing with the background. Proposed 18 resolution issued for public comment in 1988, June 1988. We 19 received comments from six organizations, namely, Duke Power 20 Company, Westinghouse, General Electric, Stephenson and 21 Associates, and EPRI.
.22 BNL, Brookhaven National Lab was contracted to
- 23 resolve public comments. The Staff with the help of BNL 24 selected a panel of consultants to address public comments 25 and make recommendations to revise the standard review plan
() Heritage Reporting Corporation (202) 628-4888 l
(
9 q -
z 1- sections.
2 The members of the consulting panel were:
3 Professor Carl Constantino, City University of New York; Dr.
4 - Robert Kennedy; Professor Shinozuka; Dr. John Stevenson; and 5 Professor Veletsos.
6 The results of the BNL contract'is summarized in 7 NUREG/CR-5347.which is published in March 1989. The Staff-8 then developed final revisions to the standard review plan 9 sections.
10 The final resolution is: the revision of standard 11 review plan section 3.7.1, 3.7.2, 3.7.3, and 2.5.2.
12 Changes resulting from recommendations of Lawrence 13 Livermore pertain to section 3.7.1 through 3.7.3. And j) 14 changes resulting from incorporation of current Staff review 15 practices pertain to SRP 2.5.2.
16- Also, changes resulting from soil-structure l'7 interaction workshop and some editorial and clarification 18 changes have been included.
- 19. All SRP changes are forward fit only. They will 20 apply to the construction permit, the operating license, 21 PDA.
22 DR. SHEWMON: Would this allow somebody to go in 1
23 and reanalyze the piping for example or something and take l 24 out some restraints if they wanted to or felt it was worth 25 their time?
) Heritage Reporting Corporation (202) 628-4888 j
i
10
! )' 1 MR. BAGCHI: This is with the office of NRR. So 2 in the licensing aspect, indeed, people are asking for use .
l 3 of this current methods and we have been allowing that.
4 DR. SHEWMON: Thank you.
5 MR. SRAUKAT: Large above ground steel tanks were 6 identified as a potential concern. And the actions on the 7 tanks we have taken is that we realize that USI A-46'which 8 is seismic qualification of equipment in operating reactors.
9 A-46 requirements includes tank review which cover 10 70 plants. Other plants the Staff had made a survey of tank 11 design confirming that many newer plants are adequate.
12 Plants-after 1980, we mean by newer plants here. Most of 13 them are adequate.
{} 14 15 Request for information issued to all other others, which is only four licensees during the time frame 16 of 1980 onwards. That we do not have enough information to-17 judge the adequacy of above ground steel tanks for 18 earthquake loading.
19 This had already been issued by information letter 20 about last month to four licensees. Those licensees are:
21 Wolf Creek; Callaway; Harris.
22 I will summarize the recommendations for SRP 3.7.1 23 through 3.7.3, this is done by Lawrence Livermore.
24 Changes in the specification of ground motion for 25 design of structures. Mainly, there are two aspects: one is Heritage Reporting Corporation (202) 628-4888
I 11 1 C')
(_,/ 1 the location of the control motion; and the other is the 2 reduction of control motion with depth.
3 Significant changes for soil-structure interaction 4 analysis, Lawrence Livermore did not like the soil-structure 5 interaction position as it stands out in the standard review 6 plan, so they proposed a new philosophy to be included in 7 the standard review plan. And based on two workshops we 8 have developed a new philosophy and that is included in the 9 current proposed version of standard review plan.
10 More specific guidelines for seismic design for 11 special structures such as buried pipes and above ground 12 vertical tanks. We have included detailed guidelines on 13 these structures, especially for tanks. Those guidelines 14 have also been issued in the information letter to these
}
15 four licensees to determine adequacy of their large above-16 ground tanks.
17 The specific criteria for combination of high-18 frequency modal response, we have included a detailed 19 specific criteria in the Appendix A to the standard review 20 plan, section 3.7.2.
21 Allowance of limited amount of inelastic energy 22 absorption in the design response of category 1 structures.
23 We have allowed the limited use of inelastic energy 24 absorption in the case of existing structures to verify the 25 adequacy of existing structures.
() Heritage Reporting Corporation (202) 628-4888
g.
i . .. .
12
. 11: DR. SHEWMON: 'How do'you do.that?
2 Can you answer the question.in 50.words or if not 3 I-can go look -- is this a higher damping?
4- MR. SHAUKAT: They stress beyond the. yield point.
5 DR. SHEWMON: That doesn't give y*u damping, just 6 a higher elastic --
7 DR. SIESS: The question.is how do you do it? Do
- 8- you make an inelastic analysis or a modified elastic 9 analysis.or change the damping or what?.
10 MR. SHAUKAT: Just make use of higher elastic 11 stresses, higher than yield-stresses.
~
' 12 ' DR. LEWIS: But that doesn't make losses.
13 DR. SIESS: In other words, the ASME code 1 14 approach. Go to a fictitiously high stress above the yield?
)
15 ' MR . SHAUKAT: Yes. Those kind of higher yield 16 stresses in the design process. But we adopted.to the 17 existing -- to justify the existing structures if there is a-18 need to go beyond the yield stress, then we'll make use of 19 it.
20 MR. BAGCHI: Let me just make a clarification.
21 This area is developing, as you know. We can't 22 legislate a particular way of doing thinga, as Dr. Siess 23 probably is aware. The stiffness relationship changes with 24 the cycles of straining beyond elastic point. And that kind 25 of characterization is in the literature and coded in the Heritage Reporting Corporation (202) 628-4888
13 l W
1 normal non-linear. antilysis codes andaat's what l's used. l 2 DR. SHEWMON: These are metal structures?
3 MR. BAGCHI: 'These are concrete structures. Metal 4~ structures are handled somewhat along the lines that Khalid.
5 had pointed out. For concrete structures the stiffness 6 relationship is characterized in terms of the' cycles of 7 motion;-- stress versas strain.
8 DR. SHEWMON: Do we have in the room a copy of 9 what it'is we're being asked to approve here?
10 MR. SHAUKAT: Yes.
11 DR. SHEWMON: Where is it?
12 MR. BAGCHI: It's a well defined experin. ental 13 verified characterization --
() 14 DR. SHEWMON: I'm not questioning your integrity 15 or ability. I just want to know how it was that energy 16 dissipation was put into the analysis.
17 MR. CHOKSHI: One of the ways it was done was by a 18 -- was is called utility factors. And what you do is modify 19 elastic response spectra by this utility factors to account 20 for energy absorption on a softer structure. And then you 21 can use your elastic analysis but account in some way that 22 original energy absorption during the non-linear phase of 23 the structure response. Other ways that Goutam described is 24 to do a time-wise non-linear analysis.
25- So I think that approach when we talk about non-Heritage Reporting Corporation (202) 628-4888
14
~
-1 . linear analysis is t'o both possibilities.
2 DR.;SHEWMON: Thank you.
L 3 ~If I can go on'to the next item.
'4 MR. SHAUKAT: Damping values.-
5 DR. SHEWMON: Yes.
i-
-6L You have'not mentioned anything about piping here, 7 yet I assume that what you're bringing before us does' deal 8 with pipes, also.
- 9. There was a pipe study group that brought forth.
10 recommendations several years ago. Have these been accepted 11 or implemented? One of those was, as I recall, a frequency 12 dependent' change in damping.
13 MR. SHAUKAT: Piping review is actually beyond the.
(} 14 scope of standard review plan sections that we are dealing 15 here. So the results have been accepted in the piping 16 review area, but not within the scope of A-40.
17 DR. SHEWMON: Could'you tell me -- to read the 18 title which says, " seismic design criteria" one might think
'19 that it involved things other than what it does apparently.
20 What structures is this limited to?
21 MR. SHAUKAT: All the structures other than piping 22 and equipment.
23 DR. SIESS: Let me add something there.
24 Seismic design criteria is a misnomer. None of 25 these changes, all of which at the section 3.7 of the
'O erie 9e aererei 9 (202) 628-4888 cexver eie-
_-___-_ D
15
- 1. ' standard review plan have anything to do with design. They 2 all related to methods of analysis. And an analysis is,not 3 a design. Once it's analyzed you still have to use code 14 rules for a design and some of the things -- now code rules 5 also affect analysis.
6 DR. SHEWMON: Now, analysis is to make sure that 7 the design rules are still good or why do you do it twice?
8 DR. SIESS: To analyze it to'get the forces, the i 9 moments,. the stresses. But they have accepted the code case 10 on damping factors long time ago.
11 But I just want to make the point that this is 12 related to analysis which is one step in the design or in 13 the reanalysis which has what's been happening more often in 14 the last few years.
(
15 MR. SHAUKAT: The code case N-411 has been 16 accepted by Reg Guide 184.
17 DR. SIESS: Yes, that's old stuff now.
18 MR. BAGCHI: One thing . .ould be pointed out. Dr.
19 Stephenson, your consultant, had made a number of 20 recommendations recently. Many of them make good sense. We 21 really don't address the question of overall design. He has 22 raised scme intriguing questions. Perhaps that is for 23 future work.
'l 24 DR. LEWIS: Following up Chet's point, just for my 25 education. :
1
()- Heritage Reporting Corporation (202) 628-4888 j
____ __ ____ _ __ _j
16
('
( .
1 MR. .SHAUKAT: Another recommendation was --
2- DR. SHEWMON: Just a minute, please.
3 DR. LEWIS: I'm really asking Chet this more than 4 anything else. Is the reanalysis done with as realistic 5 values of the yield stresses and.dampings as they're 6 available? .
7 DR. SIESS: Usually when,'for some reason,.we 8 jacked up the seismic hazard level, the reanalysis has 9 allowed real stresses and things of that sort.
10 MR. BAGCHI: That's a very intriguing question.
11 If it's a licensing issue, if it has to do with whether or 12 not to meet the general design criteria it would have to be 13 the more strictive code type of analysis. Not realistic, (J 14 If, on the other hand, we are addressing the 15 actual capacity as we would be doing for severe accidents, 16 larger than design earthquakes, things like that, then we 17 would use realistic values.
18 DR. LEWIS: Well, it's of course much more 19 difficult to use realistic values. That's what I'm getting 20 at. And there's a certain element of self-deception 21 involved in doing design with conservative values and then 2:2 doing analysis with the same conservative values, because 23 you miss things.
24 DR. SIESS: The thing is that when you're 25 analyzing or checking the design of an existing structure, O erie ee aegerei 9 cereer eie-(202) 628-4888
17 11 clearl'y'a number of the uncertainties that existed when you 2 were designing it on paper no longer exists; it's there.
3 And theoretically you should take out some of the margins 4 that went in to allow for those uncertainties for something 5 that hadn't even been built.
6 I'm afraid that legalistically if it gets into a 7 hearing type' case where there is some real reason that the 8 seismic design value went up and they've got to go in and 9 prove that it still meets the FSAR requirements for a larger 10 earthquake, they have to go back and do it just the way they 11 would calculate it before.
12 DR. LEWIS: Well, that's because there are two 13 levels of analysis. One is the analysis to show that you 14 meet the licensing criteria and the other is to find out
(}
15 whether the thing really will break.
16 DR. SIESS: But if they're looking at seismic 17 margin type case or that type of thing, that's done more 18 realistically.
19 DR. LEWIS: More realistically.
20 DR. SIESS: Well, how close we can get to reality, 21 we don't ever know.
22 DR. SHEWMON: Engineers always got to have margin.
23 DR. SIESS: We don't know how big a hole there 24 might be in the concrete because they left the vibrator in 25 the wall.
..() Heritage Reporting Corporation (202) 628-4888
l 18 J
'1- Don't laugh it's happened. It even happened in
- 2. the model down at Sandia. There was a little scale model 3- vibrator but they'left it in the wall.
4 MR.. WARD: A realistic experience.
5 DR. .- SIESS : Oh,'yes, very realistic.-
6 MR. - SHAUKAT: Another recommendation was revision 7 of damping values for design based on stress levels, and we 8- accepted this recommendation and included the damping values -
9 to be acceptable based on stress levels.
10 Direct generation of in-structureLresponse spectra 11 for equipment design. . This recommendation has been included 12 -- accepted and included in the SRP.
13 Sensitivity studies for uncertainties through
() 14 variation of parameters. SRP made it a requirement to' 15 ensure the implementation of the methodology used and we m
16 haven't accepted that recommendation, also.
17 Option to use randomly selected multiple time 18 histories. We have allowed the use of multiple time 19 histories, also.
20 Most of these recommendations were accepted. Only 21 a few were rejected and we will mention those.
22 DR. CATTON: Could you clarify something for those
~23 of us who are not in the business. Could you put that slide 24 back.
25 What is a randomly selected multiple time history?
O erica,e aegerein, (202) 628-4888 Corgeraeien
f l
"]l t
L .19 r..
] .
1 MR. CHOKSHI: If I may, Nilesh Chokshi of the 2 Staff. I 3 Originally the analysis are done with a card time 4 history, which is a record of time versus expiration.
5 DR. CATTON: Okay, I understand that.
6 MR. CHOKSHI: And instead of choosing only one 7 record as your design input, what we allow now is to use a 8 number of such records to account for possible radiations in 9 - earthquake. And systematically reading the parameters.
10 That's what that item refers to. .
11 DR. .CATTON: How do you put them together?
12 MR. CHOKSHI: What do.you is you run individual 13 and then use the average results.
{} 14 15 DR. SIESS:
DR. CATTON:
On several cases take the maximum.
It's like enveloping then.
16 DR. SIESS: Are we talking about time history 17 selection now?
18 MR. CHOKSHI: The last item, I think.
19 DR. SIESS: There are two options, am I not 20 correct, you can have multiple time histories or you can 21 have a single time history that will yield a response 22 spectrum that envelopes the --
23 MR. CHOKSHI: Design response spectrum.
24 DR. SIESS: -- design response spectrum, which is 25 that simplified thing.
Heritage Reporting Corporation (202) 628-4838
r_----
20
/")
(/ 1 DR. CATTON: Okay, 1
i 2 DR. SIESS: But they have added a requirement on 3 the power spectral density to be sure that there is not any 4 J
l 4 gaps in the frequencies that are included. '
5 Now, if you use multiple time histories it is sort 6 of like the site-specific spectrum.
7 MR. CHOKSHI: Ye ', you use number of time 8 histories.
9 DR. SIESS: The move I think will be toward the 10 single time history with the power spectral density, don't 11 you'think.
12 MR. CHOKSHI: Yes.
13 DR. SIESS: For simplification here.
/~ 14 DR. CATTON: In it's linear analysis.
(.)T 15 MR. CHOKSHI: It's linear analysis, yes.
16 DR. SHEWMON: Do you end up with any time 17 dependent properties? That is, how hard it got hit early in 18 the cycle influences, it's performance and capable later?
19 MR. CHOKSHI: If you do non-linear analysis then 20 you will be looking at a stiffness -- as you progress in l
l 21 earthquake along that time.
22 DR. SHEWMON: The answer is, that's not included 23 here.
1 24 MR. CHOKSHI: This is from the linear option, 25 that's not explicitly included.
I
() Heritage Reporting Corporation (202) 628-4888 E_-----_- -
~ ._ _ - __ - _-____-
l 21
\m/ 1 DR. LEWIS: That doesn't mean there aren't such 2 facts.
3 MR. SHAUKAT: The NUREG-1161 recommendations that 4 were rejected. We have the changes here and the reasons for 5 rejection or disposition here.
1.
6 Seismic design based on performance criterion.
7 And performance being probability of exceeding response 8 levels to be 10 to the minus 1 for SSE.
9 This performance criterion sounds reasonable in 10 some people's mind, but there is no basis provided for the 11 calibration of response levels with past criteria. So we 12 rejected this.
13 DR. LEWIS: I don't entirely understand that. Are
(} 14 you saying that it's not a good idea or that it's a good 15 idea but there is no way to do it.
16 MR. SHAUKAT: It's a good idea but there is no way 17 to calibrate it.
18 DR. LEWIS: It was unclear to me what you were 19 saying.
20 So does that mean there will be more effort into 21 trying to implement it because it's a good idea or is this 22 the end of the subject?
23 MR. SHAUKAT: Yes, I guess it's the end of the 24 subject.
25 DR. LEWIS: I see.
,/ '
( Heritage Reporting Corporation (202) 628-4888
.I 22 I1l MR. SHAUKAT: Up until we have a good way of 2 calibrating'3t, we cannot do it.
3 DR. LEWIS: Because.it is a good idea.
I "4 MR. SHAUKAT: Yes.
5 MR. BAGCHI: I don't think we ought to give up on i
6 that' idea a41,together.
7 Perhaps, Dr. Lewis, you are aware A-46 went into 8 looking'for earthquake exp<erience data and it has helped j 9 substantially. And the threshold response spectrum is based l
10 entirely on that kind of calibration. It's being done.
11 There needs to be data. Another will teach us something 12 new.
13 MR. SEAUKAT: Soil-structure interaction, new L 14 philosophy to replace existing SRP; we have done that.
{
15 Additional work was performed through-the workshop. And the 16 final position is close to the recommendations by Lawrence-17 Livermore..
18 Wave passage effects to be included in the seismic 19 design. This effect is generally not quantifiable for most 20 of the sites. It's very difficult to include it in as a 21 general guideline. So we just pulled out that idea.
22 Modal combination of closely spaced modes, the 23 recommendation was that other methods -- methods other than 24 Reg Guide 192 should also be accepted. The Staff is in a 25 position to recommend that a revision of the Reg Guide and l
Beritage Reporting Corporation (202) 628-4888 1
23
'l other. methods are already referenced in SRP as'a guideline 2- that will be accepted on a case-by-case review.
-2 Critical damping values: position was a-range of 4' values were recommended. And for those damping values
- 5. Research'had ongoing programs.and Reg Guide 161 will be 6 eventually revised. And SRPs reference to Reg Guide 161 7 right now. So as the Reg Guide 161 is already in the SRP,
'8 that will make use of the revised position.
9 Require in-situ testing to ensure confidence in 10 design methods: this is a vague requirement without' 11 specifics. And without specifics it's not suitable as a
~
12 general requirement, so we did not include it.
l l 13 Reduction in number of OBE cycles required for 14 design. Now we are asking five OBE cycles and the 15 recommendation was to reduce it to maybe three or two. And
-16 we don't have enough justification at this time to do that, i 17 so we are still using five OBE cycles.
l 18 19 20 21 22 23 24-25 Heritage Reporti.itg Corporation (202) 628-4888 1
___-_- -- - _ _ _ _ - - - - - - - _ - - - - _ - - - - - _ _ - _ _ _-___-__ A
24 i]/
t' 1 MR. SHAUKAT: Ncw we shall go to each individual 2 SRP Section.
3 The highlights of SRP Section 2.5.2:
4 Basically, SRP 2.5.2 is revised to reflect current 5 staff review practice. That has been in effect since 1979 6 as the applications came in.
7 Preferred hierarchy of ground motion 8 specifications.
9 The most preferred one is the site specific 10 criteria, site specific spectra using records suitable for 11 site conditions.
12 The second desirable one would be site-specific 13 spectra using scaled records.
(} 14 Others are spectra of NUREG 0098 and Reg Guide 15 1.60 spectra, in this order of preference.
16 These are the public comments on SRP 2.5.2:
17 The first comment was, do not consider OBE as a 18 design event, and let the utilities define the design event.
19 This suggestion would require a revision to 10 CFR 20 Part 100, Appendix A, and we consider it beyond the cope of 21 A-40.
22 Another comment was, conservative response spectra 23 for a number of sites for standard plant should be allowed.
24 This provision already exists in the SRP so 25 actually this comment is no comment.
() Heritage Reporting (202) 628-4888 Corporation 1
- 4r , .
i:
25
) 1 DR. SIESS:- Wait a minute. Let me ask you
?! something about that.
3 LIs that consistent with'the proposed revision to 4 2.5 that'says use site-specific spectra?
- i. 5 MR. SHAUKAT: Yes.
i.
6 DR. SIESS: 'It occurred to me that the use of 7 site-specific probabilistically-based spectra had at least B as one objective the development of a uniform seismic hazard 9 for different sites.
10 Am I correct?
11 MR. REITER: This is Leon Reiter, NRR. The site-12 specific spectra, in these contexts, are not probabilistic 13 spectra. The site-specific develops suites of records and 14 we take some statistical estimate of that. It is not the
(
15 probabilistic, uniform hazard response spectra which I think 16 = you are talking about.
- 17 DR. SIESS
- The Livermore report on --
18 MR. REITER: Those are not.these kind-of spectra.
19 Ho. These are the kind of spectra we have been bringing --
20 DR. SIESS: I'm talking about 2.5 r.ow.
21 MR. REITER: Right. Yes. These are the kind of
- 22. spectra that we have been bringing to the ACRS since around 23 Sequoyah, at least around ten years ago, where we evaluate 24 the appropriate.ess of what was a previously assumed design 25 level by taking a suite of records which matches the
() Heritage Reporting Corporation (202) 628-4888 i
i
^
V
- l. . . '
26 1 controlling event, and then look at the 84th percentile of l
2 that.
3 DR. SIESS: W~aere do we stand on the other 4 approach? Anywhere?
5 MR. REITER: Well, again, I think as we pointed 6 out, use of probabilistic spectra would require revision to f- 7 Appendix A. And we have had lots of conferences about.that.
8 DR. SIESS: Would require what?
9 MR. REITER: Revision'to Appendix A.
10 DR. SIESS: Yes. But you know, the uniform hazard 11 spectra made a certain amount of sense as long as we had 12 custom-designed plants.
13 But when we go to standard plants, we no longer 14 have a uniform hazard. When you take an ABWR and put it at
[}
15 Bay City, Texas, and take another one, the same standard 16 design, and put it at Rockford, Illinois, the probability of 17 excedence is by no means the same at the two' sites. Right?
18 MR..REITER: That is right.
19 DR. SIESS: So I have not gained anything by using 20 the uniform hazard.
21 MR. REITER: Well, I am not quite sure -- 1 think 22 I understand, but I am not quite sure. But let me say the 23 standardized plan gains from that it has a uniform design.
24 DR. SIESS: Oh, yes.
25 MR. REITER: And at certain places where the
() Heritage Reporting Corporation (202) 628-4888 l
27
\/ 1 hazards could be. lower you galn by taking uni ._ m design 2 rather than arguing going for a lower value.
3 A utility makes a judgment as to what salue it 4 thinka is most appropriate that will give it the most sights 5 for the least --
6 DR. SIESS: The utility is not going to have any 7 choice. He's going to come in with the standard design or a 8 custom plant.
9 MR. REITER: Yes, the standard plant designer, 10 let's say CSAR or Westinghouse, they make a decision. If 11 they want the plant applicable to more sites, they make it 12 higher. If they want it applicable to less sites, then they 13 make it lower.
/~h 14 ER. SIESS: It won't he anything uniform any more.
G 15 MR. REITER: No, there is really very little 16 uniform now. Our results from both our studies and EPRI's 17 studies indicate that following Appendix A you can get large 18 differences in the probability of exceeding earthquakes 19 depending on where you are.
20 The criteria that we use do not require 21 equivalence of seismic hazard in terms of probabilistically.
22 DR. SIESS: I thought that is what the seven 23 volumes of --
24 MR. REITER: Right. That is what that is. But 25 Appendix A does not follow those seven volumes.
() Heritage Reporting Corporation (202) 628-4888
i
. J 28 1.0 DR. - SIESS : - I am not talking about Appendix A.
'2- .I've given upion Appendix A.
3 MR. REITER: But that is what we have to follow.
4= ~DR. SIESS: You are talking like a~ lawyer, Leon. j 5' I'm. talking about how we might go about it'.
i 6- . MR . REITERt Oh, I'm'sorry. Okay.. Excuse me. I. ,;
i 7 thought you were talking about the way we do things today. I 8 DR. SIESS: We had at least a theoretical basis 9 for arriving at:a uniform hazard that was consistent-among l
- 10 sites..
11 MR. REITER: Right.
i 12 DR. SIESS: And that really isn't worth developing l I
13 if we are going to go to-standard designs.
14' b!R . REITER:. No, because then if you go to 15 standard designs, the idea is you want to develop some sort 16 of way of looking, if accepting a standard design is going 17 to be based upon some sort of assumption of hazard, then you q 18 are-tjoing to have to use that uniform design response 19 spectra to demonstrate that the level you are proposing j 20 muets that proposed hazard.
21 DR. SIESS: At the worst site. At any other site )
'l 22 it would be better.
23 MR. SHAUKAT: Yes.
24 DR. SIESS: Okay. I'm clear.
25 MR. SHAUKAT: Highlights of SRP Section 3.7.1:
Heritage Reporting Corporation (202) 628-4888 1
--_..___-_-O
l '!
? . i 29
- i. Control-motion location either at the-surface or i
2 at the rock. outcrop. Previous presentation of SRP, or l'
! 3 current presentation of SRP actually has the control motion 4' location at the foundation levels.
5 Power spectral density requirement to demonstrate i 6 ' adequate power at frequency ranges of interest, when single-l 7 -time history'isJused.
8- This is to detect the lack of power at different
- 9. frequencies.
10 Option to use multiple time histories. Multiple 11 time history would also in some way detect the adequate 12 power at all frequency ranges.
13 Commenta received:
{} 14 Design response spectra, vertical should be equal 15 to two thirds' horizontal. As of now we have half, and there 16 has not.been a justification existing for all sites. So we 17 did not adopt this recommendation.
18 More definite criteria for duration of seismic 19 input is-needed. We have adopted this for Reg. Guide 1.60 20 type spectra.
21 Power spectral density requirement questionable 22 and 4Med more detailed guidelines. This was a comment on 23 the power spectral density function version that went out 24 for public comment. That version has been changed 25 substantially, based on efforts of Doctor Kennedy and Doctor
() Heritage Reporting (202) 628-4888 Corporation
30
/'T
(,/ 1 Shinozuka during public comment resolution period. So the 2 revised position on power spectral density is quite 3 different from what was questionable here. And that is now 4 included in the Appendix A to SRP 3.7.1.
5 Multiple time histories requirement of five 6 minimum is too high. We have adopted four minimum time 7 histories based on public comments, as they are justified, 8 saying it is costly to do five. There were discussions 9 among the members of the consultants during public comment.
10 Some people said as to three, some people said as to four, 11 and some people said as to five. So we sort of took a 12 middle route and we accepted four minimum time histories.
13 And if somebody uses four multiple time histories, then
{} 14 15 there would be no requirement for power spectral DSD check on it.
16 DR. SIESS: I think it is nice that four is both 17 the mean and the median in chis case.
18 MR. SHAUKAT: Yes. Mean and median both. Yes.
19 (1 ughter) 20 MR. SHAUKAT: Damping values used should correlate 21 with stress levels based on ASCE Standard 4-86. And we have 22 adopted that recommendation, o.- that comment, and we have l
23 included the use of ASCE 4-86 as a guidance.
24 Highlights of SRP Section 3.72:
25 Soil-stricture interaction. This calculation,
() Heritage Reporting Corporation (202) 628-4888
l 31 \
1 reduction of control motion with depth limited to 40 1
2 percent. We have included this-limit based on the LOTUNG l 3 experiment and the questions and answers we received from 4 public comment on LOTUNG experiments.
5 Enveloping requirement of results of two methods 6 eliminated. The current version of SRP has a requirement 7 that analyzes each structure by two methods and enveloped 8 the results of the two methods. That is to take care of 9 uncertainties. And we have now more realistic methods of 10 soil-structure interaction so there is no need to have the 11 enveloping requirement, and we have eliminated that 12 requirement.
13 Modal combination of high-frequency modes. We
{} 14 have included more guidelines on it.
15 Options of direct generation of floor response 16 spectra has also been included.
17 The comments received:
18 In the soil-structure interaction we had included 19 two alternates in the standard review plan section that went 20 out for public comments. Our intent was not to have those 21 two alternates in the final SRP version, but the intent was 22 to seek the public comment on those two alternatives. And 23 those two alternatives have been finally deleted and 24 realistic methoda have been provided in the SRP. Those 25 realistic methods also took the advantage of answers on
() Heritage Reporting Corporation (202) 628-4888
L 32 1 LOTUNG experiment questions.
1 2 We have talked about the elimination of enveloping 3 of two methods, which we have eliminated.
4' Modal combination. The comment was, allow the use 5 of ASCE standard 4-86. We said it will be permitted on case.
6 .by case basis.
7 .High frequency modos. The comment was, include 8 other acceptable methods, other than given in the Reg. Guide 9 and SRP.. We have given one method in the SRP and other 10 approaches are mentioned as a reference and they will be 11 reviewed on a case by case basis.
f 12 Highlights of SRP Section 3.7.3:
13 Category I, buried pipings. Methodology of ASCE
(} ' 14 Standard 4-86 and NUREG 1161 are referenced in the SRP.
15 And tank design requirements are included.
I 16 Public comments basically are buried pipings, 17 conduits, et cetera:
18 The comment was, reflect the results of NUREG-19 1061, this is piping review. And our disposition is, the 20 NUREG-1161 of Lawrence Livermore reference is enough for 21 buried pipings and conduits design and analysis. So we have 22 referenced 1161.
23 Include reference of ASCE 4-86. And ASCE Standard 24 4-86 reference is provided.
25 Include reference like ASME Section III Appendix
() Heritage Reporting Corporation (202) 628-4888
33
\/ 1 N, " Dynamic Analysis Me _ ads." We feel that the ASCE 2 Standard 4-86 has enough details in it and the reference to 3 that is just sufficient. So we just included ASCE Standard 4 4-86 as a reference in the standard review plan section.
5 That concludes my presentation.
6 DR. REMICK: Questions.
7 DR. SHEWMON: Yes. I would like to, if I could, 8 back off a little bit and try to get a statement of what the 9 problem was that we have the solution to in front of us.
10 That is, A-40 had to do with apparently the 11 adequacy of design criteria, both excessive conservatism 12 and excessive nonconservatisms. And that uncertainty was 13 what was defined as the unresolved safety issue?
19 L/
14 MR. SHAUKAT: Yes.
15 DR. SHEWMON: Is that a fair statement?
16 MR. SHAUKAT: Yes. Both conservatism and 17 nonconservatisms. '
18 DR. SIEUMON: So what this agglomeration of 19 documents and plans does for us is to do at least a better 20 job than we were doing in 1977.
21 MR. SHAUKAT: Exactly.
22 DR. REMICK: Other questions.
l 23 DR. KERR: Any comments, Mr. Siess?
24 DR. SIESS: No. I think the Staff has done an 25 excellent job of trying to bring together some divergent O Heritage Reporting Corporation
()
(202) 628-4888 L_ _ _- _ _
7- :34 l' ' views here,. from the industry as well as among the national 2' ' labs, I believe. l
- 3. And they have compromised in some cases, but I l -4 think it is a good compromise. It's an inte111aent 5 compromise. None of this is going to affect the safety of
.6 the existing class'and none of it is backfit'. That is
'7 important. There is nothing backfitted in this whole 8 program. The regulatory analysis just could not find enough 9 effect of it.
10 For future plans, there will be some 11 simplification in analysis. It is certainly going to be 12 . easier'for the licensee and the staff to understand:what 13 each other is doing, because there are many clarifications.
(} 14 And the only thing that has been changed that does 15 have safety significance is the above-ground steel tank 16 position. That has been changed in the standard review 17 . plan, but it has not been made a backfit, because it can't 18 handle separately.
19 Now, this is a safety issue because we know from 20 experience with large earthquakes that there is about a 40 21 percent chance the vertical steel tanks are going to be 22 damaged. Some of them have slid off their foundation, 23 they've broken pipes and so forth.
24 And until somewhere a few years ago, some people 25 analyzed those by a simplified method assuming the walls
() Heritage Reporting Corporation (202) 628-4888 l
-__--- _ _ O
r b
35 4 .
l'= with ridges on them, and there's a factor ~of about.2,-2-1/2 2 unconservatism in that.
3 And this has been a part of A-46, which was_the
~
4 seismic qualification program, and the staff has figured out 5 now that a lot of the plant really analyzed it right.
6 Everything since 1984 was reviewed on the:new basis, and 7 they have it narrowed down to four plants with six units, 8 and they are not sure. And they have letters out to those 9 plants asking them how did you analyze it. But that is a 10 real concern.
11 MR. WARD: Okay. So that is some backfit there, 12 possible.
13 DR. SIESS: It's not going to be backfit by the 14- standard review plan, it is backfitting under A-46.
(}-
15 MR. WARD: Okay.
16 DR. SIESS: Just to mention, and I say it
-17
. seriously, on the Maine Yankee seismic module study, where 18 it turned out that there are high-confidence, low 19 probability earthquake, .21, versus a design basis, was
- 20 what? .10. So, you know, it's high confidence, low 21 probability was still twice the SSE. But what governed that 22 was the vert Leal seal type. Once that tank is fixed, that 23 .2 went to about .3, which is a nice, comfortable margin.
24 So we know it is a weak spot, but it is being 25 handled under the A-46. But the letter is already out.
' () Heritage Reporting Corporation (202) 628-4888
l l
36 i r'x i
(-) 1 DR. SHENMON: What is the title of A-46? q 2 DR. SIESS: Seismic qualification of equipment in j 3' operating nuclear power plants. It will be in the letter.
1 4 So there's no backfits. Generally the 5 improvements make it a lot easier to communicate with l
, 6 licensees although now with standard plans, you don't have 7 to communicate with as many people, assuming we have 8 standard plans.
l 9 One point I had asked of the Staff and the 10 subcommittee, and I am going to ask it again here, just in 11 case anybody wants to add or subtract from it: it is still 32 not clear to me just where the interface is going to be 13 between the seismic characteristics of the site as
(} 14 determined in a preapproved site and the seismic design 15 basis for a standard plant design, whether that interface is 16 going to be a seismic motion input at the base slab of the 17 plant or a seismic motion ,at the ground surface, or whether !
18 the soil properties and site properties must fit within some 19 range that was used by the designer.
20 And I didn't get a good answer to that. And I 21 don't think that we necessarily need it here. But I didn't 22 see a whole lot of evidence that the staff had been thinking 23 about that interface with standard plans.
24 MR. SHAUKAT: 1 think based on our experience with 25 GSAR, it would have to be both an input which would be
() Heritage Reporting Corporation (202) 628-4888
)
37
/~S
'\_) 1 basically in the free field as well as the site properties 2 like sheer wall velocity, depth of embedment, water table 3 levels and the parameters which are uniquely site specific, 1
4 and to compare those with the envelopes which were used in 5 the design, and see if those are within the envelope. ;
I 6 DR. SIESS: Now, I come in with a site. I haven't 7 decided what I am going to put on it.
8 What are you going to ask me to provide you frr 9 sit approval?
10 I mean, I don't know whether I am going to put an 11 AP-600 there or module HTGR, General Electric advanced 12 boiling water reactor.
13 MR. REITER: Those are standardized plans?
14 DR. SIESS: I don't know. It's a preapproved
{~}
15 site. I don't think there's anything in the rules that say I 16 that a preapproved site can only be used for a standard l 17 plan.
18 MR. REITER: If they want to use a standardized 19 plan, the interface requirements have to show that the site-
- l 20 specific characteristics, both in terms of ground motion --
21 DR. S;ESS: I don't know. I come in for a ,
22 preapproved site. What are you going to ask me? Are you 23 going to ask me what plant I am going to put there? Is that 24 in the rule?
25 MR. REITER: Well, no. In terms of these l () Heritage Reporting Corporation (202) 628-4888
y y r
38 1 regulations, if they want to' approve the siter then they 2 would have to ---without assuming anything about the' ground.
3- motion?'
4 DR. SIESS: -I'm coming in 'for a~preapproved site.
5 What would I have to provide you? I don't think you ought 6 to try to answer it. I don't think you've thought about it.
7 I think you always think about that site and that' standard.
8 plant out t';are, and looking at_them this way.- And they -!
9- don't come onat way. They are supposed to come one at a 10 time.
11 It is not pertinent to this particular resolution.
12 But I do wish you would think about it a little bit.
13 I have nothing else, Mr. Chairman.
Okay. And there will be a letter, is
/
{ 14 DR. REMICK:
15 that rir$t ?
16 DR. SIESS: I am drafting a letter which approves
- 17. what the Staff is doing and-I haven't been able,-although I 18 think they have done a good job, I haven't been quite been 19- able'to bring myself to say that, without at the same time 20 commenting on the 12 years.
21 So I think as a compromise I will just stay mute.
22 (Laughter) 23 DR. REMICK: Any further comments by the 24 committee?
25 ('N o response)
Heritage Reporting Corporation (202) 628-4888 l . _ _ _ _ _ - _ _ _ _ _ _ _ -
f
-1 39 i b 1' DR.-REMICK: If not,.thank'you very much. 'The 2 next item, Dave, is.yours,- I assume the' Staff-are not here.
3 J- I suggest we t'ake an-11-minute break until ten- J
~
4' minutes before the hour, come back, and;Mr. Fraley, could we 5' .take up-future activities at that time?
6 NR. FRALEY: Yes.
7 DR. REMICK: So let's traks - break until ten 8 minute to the hour.
9 (Whereupon, a brief recess was taken.)
10 11 12 13 O" 15
-16 17-18 19 20 21 22 23 24 25
() Heritage. Reporting Corporation (202) 628-4888
_-_ _ ___ =_-_____ - _ __ .
40
[
- (G
.. _/ 1. DR. REMICK: Let us proceed.
2' MR. WARD: While they are coming.up. There was a 3 'SECY paper in 1988 which was the integration plan for-4~ closure of severe accident issues, and that had six 5 elements. And one of those elements was that=there would be 6 .a containment performance improvement program within the 7 staff. And this was intended to look at the several classes 8 of existing containment systems, BWR Mark I, II and III, the 9 ice condenser, and I guess large dry. I am not'sure at the 10 moment.- I have forgotten. And to develop any relatively 11 near term, well any improvements that were perceived to be 12 necessary or any requirements for improvements that were 13 perceived to be necessary.
14- Earlier this year we reviewed the program that was
- 15. developed for the BWR Mark I and we commented on that. And 16 I think you have heard quite a bit about that recently. In 17 fact just recently the Commissioners have approved'a version
- 18. of what the staff had proposed for Mark I improvements.
19 There was also a draft paper prepared by the staff 20 which we got last month, their views on potential 21 improvements in Mark II. I have not yet had a chance to 22 study that. So I do not really have any comment on it.
23 What we are to hear about today as I understand is 24 a briefing and I gather that it might include some comments 25 on this Mark II paper. But I believe that it is to be a
() Peritage Reporting Corporation (202) 628-4888
41
() 1- briefing on'_the status of the overall program. Now this'is
-2 just an information briefing. We have not been asked or I.
3 Edo not think that we are in a position to make any comments 4' or to write a letter for example at this meeting.
5 There was to be a draft paper, I guess that it 6 would be another SECY paper being developed, but we have not 7 yet seen that, I mean covering the subject of the overall 8 program. We have not yet seen that. I presume that we are 9 going to hear something about that today. But I will repeat 10 that this as I understand it is an information briefing.
11 Are there any comments from anyone else?
12 DR. KERR: You referred to a SECY which was an 13 integration plan. I would suggest that you use the word 14 purported to be an integration plan.
.( J' 15 MR. WARD: Okay. Bill Beckner I believe is going 16_ to lead off for the staff. Bill, I will just turn it over 17 to you.
18 MR. BECKNER: Thank you. As Mr. Ward indicated, 19 the purpose of this presentation is to come down and just 20 give the subcommittee an update on where we are at this
- 21 point in time and what we are doing. I plan a relatively i
22 short presentation. I think that it was scheduled for an 23 hour. My plan is to go through about four or five or maybe l
24 six slides to give you an overview of where we are with the 25 goal of leaving enough time for any detailed comments or
() Heritage Reporting Corporation (202) 628-4888 l
42
/~x
.V 1 questions that the subcommittee might have.
2 In addition to the handout however, I have a L
3 number of more detailed slides giving a little bit of status 4 report on challenges and improvements that we are looking at 5 for the different containment types. I will not go through 6 unless there are any specific questions. What I will do 7 though is very briefly just highlight for each containment 8 type some of the major things that we are looking at. So 9 again I plan a relatively brief presentation and then give 10 the committee a chance to ask questions or make comments.
11 (Slides shown.)
12 MR. BECKNER: By way of background, the 13 containment performance improvement program is only one part 14 of a larger plan ' hat I think as Bill Kerr indicated has 15 been called an integrated approach. I will not read all of 16 the slide because I think that you are aware of it. But 17 basically the container performance improvement program was 18 designed to see whether there were any generic type 19 challenges that we might want to make changes to 20 containments.
' 21 One of the key issues that was raised particularly 22 when we went to the Mark I effort was just how does the CPI 23 program fit in with other parts of this so-called integrated 24 approach to closure of severe accident issues. In 25 particular one of the major questions that the ACRS raised
() Heritage Reporting Corporation (202) 628-4888
43 1 was how does it interact with the IPE, the individual plant 2 examinations. I will try to address that to some degree as 3 I go through my presentation.
4 Again continuing with background. The staff did 5 complete their efforts and they did make formal 6 recommendations to the Commission as far as the containment 7 performance improvement program for Mark I back in January.
8 Of course, this was reviewed by the ACRS. There were five 9 specific items that the staff recommended. These are 10 delineated I believe in SECY 89017 which I think has been 11 made available to the public at this point in time.
12 The ACRS reviewed that paper. And at that point 13 in time their recommendations were that these items be
("N 14 considered in the IPE process. Since that time very
%-]
15 recently I believe at the end of June we did hear from the 16 Commission, and they have given the staff direction on to 17 proceed relative to the Mark I effort.
18 Specifically the Commission approved the hardened 19 vent that had been recommended by the staff. I think what 20 the Commission said was that the staff was directed to 21 approve any hardened vent systems that were voluntarily 22 installed by Mark I owners and then proceed with plant 23 specific backfits for the other Mark Is to see if indeed 24 they would be cost effective for those plants. In addition, 25 the Commission approved accelerated implementation of the 1
() Heritage Reporting Corporation (202) 628-4888 l
44
/~T I k/ 1 station blackout rule. This is a staff action which is 2 indeed ongoing. Other items were directed to be put into i 3 the IPE.
4 DR. KERR: Excuse me. That was accelerated 5 compared to wh&t?
6 MR. BECKNER: I think that the desire was that the 7 staff would not be the critical path on any of the review 8 processes.
9 DR. KEhnt Oh, I see. Thank you.
10 MR. 3ECKNER: The other items are the improved ADS 11 depressurization capability, the alternative water to vessel 12 and sprays, and item four which is improved procedures were 13 directed to be put in the IPE with one exception. When the
() 14 Commission mentioned the hardened vent, they also indicated 15 that appropriate procedures for that vent use should be 16 included. That is way of background on the Mark I program.
17 We are just starting to think about implementing the 18 Commission direction and it has been very recent that the 19 Commission gave us that direction.
20 Efforts since January have primarily been or 21 totally been concentrated on the other containment types.
22 We essentially completed the work back in January on 23 Mark I, although obviously Mark I efforts will pick up again 24 as we implement the Mark I recommendations. The purpose of 25 the meeting here again is to just provide the ACRS with a
() Heritage Reporting Corporation (202) 628-4888 j i
r-45 i l' status' report of where we'are and what we are doing, j 2 As David' Ward indicated,_we are in the process of: ,
3 preparing'a' status report to the Commission. The intent'of 4 thia is to give the Commission some status.of where we are, 5 just like we are here giving the ACRS a status report. The' 6 intent was to try to get the Commission paper.and the ACRS 7 meeting along about the same time. We'do have a draft of 8 the paper, but I th3nk that it will be at least a few weeks 9 before we have a goou ..augh draft I think that we want to 10 start showing around. But the intent is to try.to get'that 11 paper out very shortly, hopefully this month but maybe
' 12 August.
13 Our current plans are also to have a workshop for fg . 14 the other containment types in September. We have got a
'O
-15 tentative date I believe of September 28th and 29th in 16 Bethesda where that workshop would be. I view this workshop-17 as being a little bit different from the workshop that we 18 had on Mark I. That was held back in February up in 19 Bn1timore.
20 That workshop was geared towards primarily looking 21 at the liner melt through issue where there was a lot of 22 research that had been done, and there were a lot of 23 technical experts who had differing views on it. And a l 24 large part of that workshop was geared towards trying to 25 understand the research and to reach some conclusions on Heritage Reporting Corporation j O- (202) 628-4888 i:
l-
__._._____._.___m_____ __.
It' L
h.
46 1 that technical. issue;
- 2. I believe that for this workshop that it will 3 simply be a presentation of some of the initial conclusions L 4 .that the staff has come up with regarding a number of 5 challenges and potential improvements, and'again scliciting
- 6. industry and public feedbacx on some of those initial 7 conclusions. So it would be sort of a different type of
. 8 meeting.
9 MR. WARD: What are the tentative dates of that 10 again?
11 MR. BECKNER: September 28th and 29th in Bethesda.
12 Again that would be officially announced through a Federal 13 Register notice probably at least a month in advance.
(} 14 Our current schedule calls for completing the bulk 15 of the CPI program in January and making our recommendations 16 to the Commission at that point in time. However, I need to 17 highlight that there are a number of things that I-think 18 that I need to be stronger than saying that there are 19 potential problems that probably will delay this effort.
'20 First of all, 1150, its second draft has been out, 21 but a lot of :he detailed backup for that is not yet 22 available. I think that some contractor reports are still 23 being prepared. So to the extent that we are trying to make 24 use of the 1150 information, that is a potential problem.
25 In addition, there is a recent Limerick decision
() Heritage Reporting Corporation (202) 628-4888
t.
'I r
. r-47 I
~
1 requiring looking at severe accident desis , mitigation.
2; alternatives in the. context of NEPA. We are being drawn a 3 'little bit in support for that. So it does potentially 4 . impact our staff. The biggest potential impact however is 5 -implementation of Mark I improvements.
E6 DR. KERR: Ercuse me. Has the Commission decided 7 not to appeal that decision on Limerick?
8 MR. BECKNER: I do not know if the Commission has 9 reached a decision at this point in time.
10 DR. KERR: Thank you.
11 MR. BECKNER: I know that there is a paper givx.',g 12 recommendations, but I have not seen the response.
13 The biggest thing of course is the implementation
() 14 of the Mark I improvements. We are potentially looking at 15 trying to support NRR in the plant specific backfit analysis 16 of the Mark I hardened vent. So there is a likelihood of a-17 delay and this does present some problems when you are 38 looking at how it interacts with the IPE process.
19 DR. KERR: In the case of those plants that have 20 asked for permission to install a hardened vent and the 21 Commission recommended or asked that you approve these, did 22 that mean approve without analysis or improve with analysis?
23 MR. BEOKNER: I think that is in reference 5059.
24 DR. KERR: In other words, if the licensee has 25 done an analysis and has concluded that there are no Heritage Reporting Corporation (202) 628-4888
48 r's
() 1 unreviewed safety questions?
2 MR. BECKNER: That is my understanding. That is 3 just from reading the SRM.
4 DR. KERR: Thank you.
5 MR. WARD: But they are not likely to corce to that 6 conclusion, are they?
7 MR. BECKNER: Pardon me.
8 MR. WARD: Do you think that they could come to 9 that sort of conclusion, a 5059 conclusion that there are no 10 unreviewed safety questions?
11 MR. BECKNER: Again I am not sure of the details 12 of how this is implemented. We have not had the time to 13 absorb and digest what the Commission has directed to us. We I e- 14 have had this thing for about a week.
15 MR. CARRCLL: I think that they have already come 16 to that conclusion. Because they have had venting in their 17 operating procedures.
18 MR. BECKNER: That is correct. Venting exists at 19 the plants today under the existing procedure.
20 MR. WARD: If you can believe that there are no 21 safety questions with existing systems, I guess that you 22 have to believe that a hardened vent would help.
23 MR. CARROLL: Is there a common understanding as 24 to how to size this hardened vent?
25 MR. BECKNER: We specifically recommended I think Heritage Reporting Corporation (202) 628-4888
g '
_4 9 -
l' one percent.
2 MR. CARROLL:- I guess that--I am aglittle puzzled.
3 by the press. release at least. It just says staff,.go out 4L and approve whatever these. guys bring in. That.is almost 5 the way that I read it.
6 MR. BECKNER: The'SRM is'a little bit more 7 specific but not a whole lot.
8 MR. CARROLL: Okay.
9 MR. BECXNER: And we are meeting this. afternoon I 10 think with NRR to' discuss this.
11 MR. WARD: When it says approve, I presumed it 12 meant review and approve.
i 13 MR. CARROLL: The words in the press-release'is, 14 "The Commission has directed its staff to approve the
}
15 installation."
16 MR. WARD: But does it not go without saying.that 17 means review.
18 MR. CARROLL: So'you are sticking with the one 19 percent?
20 MR. BECKNER: It was our judgment initially that 21 that was the most likely thing. Venting will occur many, 22 many hours after. It is not designed to handle ATWS.
23 MR. SHAUKAT; Jay, the SRM is on page 43 of that.
24 MR. BECKNER: As far as what we are doing, we are 25 proceeding in a manner at least as far as information
.O rie 9e eerei 9 cereer eie-(202) 628-4888
i 50 )
f) 1 gathering similar to what we did under the Mark I program.
1 2 We are trying to make use'of existing information to the )
3 degree possible. We are making use of the latest results ;
4 .from the 1150 as it comes available. Also the Lasalle 5 effort which is still ongoing. We are trying to follow it 6 as well as a lot of other PRAs that have been performed by 7 industry.
8 We are also interacting with the accident 9 management program which I will talk about_briefly, in order 10 to primarily identify what the containment challenges are 11 and what potential improvements might be.
12 DR. KERR: Is that just based on the fact that 13 almost anything can be improved, or have you decided that 14 all containments need to be improved, or are you looking to 15 see if containments need to be improved?
16 MR. BECKNER: We have not reached conclusions yet 17 I think is a fair answer. Right now we are looking to see 18 what the problems might be, what the fixes might be, and we 19 will try to reach a conclusion from that standpoint.
20 DR. KERR: What criteria are you going to use to 21 reach a conclusion that improvement is or is not achievable?
22 MR. BECKNER: I think that it probably will depend 23 on what the form of our recommendation is. If'we go through 24 and make a recommendation for a generic fix, obviously the 25 backfit rule with the Mark Is would be the criteria.
Heritage Reporting Corporation O (202) 628-4888
51
-ly DR. .KERR:- In~other words, it will just be a 2 cost benefit.
3' MR. BECKNER: Cost benefit'.
'4- 'DR. KERR: Cost' benefit analysis, and 5
independently of how well the containment performs. If 6
there are improvements that are cost bene'ficial, you would 7 recommend them.-
8 MR. BECKNER: Not totally independent. ' Cost 9
benefit is the part of the regulatory analysis that gets the 10 most attention, but it should not be the only consideration.
11 DR. KERR: What are'some of the other 12 considerations?
13 MR. BECKNER: Simply judgment on the need for it f-14 and the benefit to safety. Cost benefit is really the only 15 quantitative ruler-we have.
16 DR. SIESS: What would be the basis for judgment.
17 on a need?
18 MR. BECKNER: On a need?
19 DR. SIESS: Yes.
20 MR. BECKNER: I think that this is raising the 21 things that we discussed duling the Mark I effort. The 22 staff has used the cost benefit analysis primarily.
23 DR. SIESS: The cost benefit analysis you are 24 equating to need, if it is cost beneficial they need it?
25 MR. BECKNER: At this point in time yes.
Heritage Reporting Corporation (202) 628-4888 1
52 L ( 1 DR . : SIESS: That is an absolute distortion of the j 2 English language. Need has nothing to do with cost benefit.
3 Cost benefit is whether you can justify doing something.
4 MR. BECKNER: Whether it is cost effective. We 5 are using the backfit rule which cost benefit is the second 6 part of it. The'first part of it is that it hasIto be a 7 significant safety improvement.
8 'DR. SIESS: Oh, okay.
9 MR. BECKNER: That is largely judgmental.
10 DR. SIESS: And a significant safety improvement 11 is judgmental?
12 MR. BECKNER: I have nc definition of significant.
13 DR. SIESS: So you cannot tell us in advance what 14 you would consider a significant safety improvement, but you 15 think that you will be able to tell us after you have made 16 'it why you considered it a significant safety improvement?
17 MR. BECKNER: I think that if we make a 18 recommendation that we would have to indicate why we thought 19 it was a significant improvement to safety.
20 DR. SIESS: But not why a significant improvement 21 in safety is needed. If I could change the core melt 22 probability from ten to the minus eight to ten to the minus 23 six, you know, that is two orders of magnitude. And if I L 24 say it real fast, that sounds like a significant improvement 25 to safety.
Heritage Reporting Corporation
- () (202) 628-4888 L-_ _- _
53 o
'(_). 1 And would that be considered a good argument in 2 the public interest?
3 MR. BECKNER: Again we are discussing I think the 4 very valid thing that we discussed under the Mark I program, 5 that if a plant meets a safety goal or if it has got ten to 6 mirus six or ten to the minus seven core melt frequently, 7 when is enough enough.
8 DR. SIESS: But you are going ahead on Mark I to 9 meet those criteria.
10 MR. BECKNER: We were not conviaced that Mark I 11 met those criteria.
12 DR. SIESS: The Commissioners were.
13 MR. BECKNER: Fardon.
/"T. 14 DR. SIESS: But the Commissioners were.
V 15 MR. BECKNER: I am not sure what the Commission 16 felt. ,
i 17 DR. SIESS: But you are doing it on the Mark I 18 because the Commission told you to?
19 MR. BECKNER: No, I do not think that we were 20 convinced that the Mark Is had 10 to the minus 6 core melt 21 frequency.
22 DR. SIESS: You do not believe the PRAs then?
23 MR. BECKNER: I only had six PRAs. To my l
l 24 knowledge, one of them had a core melt frequency of 10 to 25 the minus 6.
l
() Heritage Reporting (202' 628-4888 Corporation l
l i
u_ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ . _ _ !
i 1'
i 54 rm J) 1 DR. 3IESS: But then would you treat that plant 2 separately from the other five?
3 MR. BECKNER: That plant already had in effect the 1
4 improvements that we recommended to a large degree.
5 DR. SIESS: That is what brought it down to ten to 6 'the minus six?
7 MR. BECKNER: Correct. Peach Bottom in effect in 8 the 1150 analysis.
9 DR. SIESS: And when did the tan to the minus six 10 become the criterion for core melt?
11 MR. BECKNER: I am quoting ten to the minus six 12 because that is the Peach Bottom number.
13 DR. SIESS: That ten to the minus six for a large r-' 14 release is the safety goal.
15 MR. BECKNER: Yes.
16 DR. SIECS: Ten to the minus four for core melt.
17 Well, I do not know what it is for core melt. That is a 18 matter of interpretation I guess.
19 MR. BECKNER: These are the same types of issues 20 that we actually have dealt with in Mark I.
21 DR. SIESS: I guess that you are saying that you 22 did not answer them, and so there is no point in answering 23 them now.
24 MR. BECKNER: I did not say that. I said at this 25 point in time that we have not determined what
(~ Heritage Reporting Corporation l (202) 628-4888
55
(') 1' ' recommendations we are going to make.on the other 2 containments.
T3 DR. SIESS:- On the Mark I?
4 MR. BECKNER: On the other containments.
5 DR. SIESS: But you have decide'd on the Mark I?
15 MR. BECKNER: That is right.
.7 DR. SIESS: And I was trying to find out what the 8 basis was there assuming that mayb'e you would use the same L 2 9 basis for the Mark II or the Merk III.
10 MR. BECKNER: 'The basis was that we, felt'that it 11 would-be,a significant reduction in risk, and second of all-l :12 that'it was cost-effective.
13 DR. KERR: Well, you also as background for the 14 . Mark I it seems to me had public statements by people who
. O.'
- 15. ,
held fairly responsible positions in our NRC saying.that 16 given core melt that Mark I containment would almost 17 certainly fail early on.
18 MR. BECKNER: Yes.
19 DR. KERR: So are you likely to arrive at a 20 similar conclusion for Mark IIs and IIIs?
21 MR. BECKNER: I think that is addressed at a lower l-22 point here, and the answer is no. Obviously we are less 23 concerned about the large drys in the Mark IIIs. The other 24 containments, the Mark IIs and the ice condensers, there are 25 some concerns there, s but not as large as the Mark Is.
Heritage Reporting Corporation 1- (202) 628-4888 1
m_____________-______. _ _ _ _ _ _ _ _ - - - _ _ _ ~ _ _ _ . _ _ _ _ _
l-56
! 1 MR. CARROLL: Can I go back to something that you'
- 2. said earlier that one of the problems that may delay your
.3 efforts is the fact that contractor reports that are part of-
-4 NUREG 1150 are.not completed yet?
5 MR. BECKNER: Yes.
6 MR. CARROLL: How widerpread is that, is it one
.7 report or is it the whole bunch, what is the' schedule for.
L.
8 getting that completed?
9 MR. BECKNER: I think the problem is the level of 10 detail that you need to get into or want to get into. I 11 think that we can handle that. problem, because we can talk 12 to the 1150 contractors and so forth. The bigger problems I 13 think is some of the other thin,7s that I have talked about.
14 MR. CARROLL: The reason that I asked the question 15 was how'do you feel that this was going to impact the peer 16 review group?
17 MR. BECKNER: I cannot address that. I am 18 assuming that'they have got that schedule to meet the peer 19 review.
20 MR. CARROLL: Is it a lot of reports?
21 MR. BECKNER: I cannot answer that. I think that 22 it depends. The detailed stuff has not been documented yet 23 to my knowledge.
24 There are a couple of things that I want to hit on 25 this. I want to talk about venting because that was the
'O Rerleaee Regereine (202) 628-4888 corgeration l
k
,. 57 1
- 1 important thing under the Mark Is or the big thing. I want' 2 to talk about thEt'as far as the other containment types.
3 But let me skip that briefly until I give-you a short 4 summary of what we are finding for each of'the' containments.
5~ I'want to skip to the next to the last slide'that 6 I will use. What we are looking at here from our. initial 7 conclusions is that our rrSommendations are going to be a 8' lot' broader than what they were for the Mark I program.
9 This is driven not only by the' Commission decision as far as 10 how to treat the Mark I improvements, but it is also being 11 driven to some degree as far as what we are finding.
12 We_obviously could still or might make 13 recommendations for specific generic improvements.. But we 14 also will be looking.at things that might well be done'under.
([
15 the IPE. We have already identified a number of things and 16- we are working on one thing that I will talk about in a 17- moment that is more appropriate under the accident 18 management program. And of course we are identifying areas 19 where we simply do not have enough information right now and 20 will need more research.
21 So again looking in my crystal br'1, the types of 22 things that we are looking at, they lend themselves to 23 really a broad range of recommendations at this point in
~24 time.
25 DR. CATTON: What is happening with the Mark I
( Heritage Reporting Corporation (202) 628-4888
T 58
'l ' liner' question?
2 MR. BECKNER: Right now the resolution to that 3 under the Mark I program in effect was the consensus that 4 seemed to come out of the Mark I workshop that water was 5 good for you. We could not quantify it. No one could 6 quantify just how good it was for you, but it was generally _
7 good for you and it would not hurt. So basically on that 8 basis we recommended improving the reliability of the 9- sprays.
10 As far as what we did as far as the cost benefit 11 from that, we said that we cannot quantify it. But we said 12 'even if the water were not to prevent the liner melt through 13 that it would provide some degree of scrubbing for fission 14 products. We again questioned a number-of experts and came 15 up with a factor of three that water might scrub fission 16 products and we used that in our risk assessment and our 17 cost benefit.
18 DR. CATTON: So you still do not know whether or 19 not you are going to fail the liner?
20 MR. BECKNER: No, we do not. We know that water 21 is going to help the situation but we cannot quantify it.
22 We stated that in the Commission paper and there is ongoing 23 research in that area to help quantify it.
24 DR. CATTON: Is there any kind of a schedule 25 associated with that?
() Heritage Reporting Corporation (202) 628-4888
(: .
'( f 1 MR. BECKNER: I would like to get a better answer 2 to that by the end of the year but I am not sure that we 3 will get it.
J 4 MR. WARD: Why when. Bill? I did not hear you.
5 MR. BECKNER: I would like to have it by the end l
h 6 of the year. Because it to somefdegree impacts some other 7 containment types, that same type of phenomenon. But I am 8 not sure that we will have enough insights at that point in 9 time.
10 DR. KERR: It seems to me that in order to arrive 11 at specific recommendations for generic improvements and 12 recommendations for additional research that you have to 13 first develop-some general guidance on how you expect-14 containments to perform, rad we are likely to refer to it as 15- -containment performance criteria.
. 16 Are you working on this?
17 MR. BECKNER: We are not development the 18 containment performance criteria. ,
, 19 DR. KERR: How do you know what additional 20 research is needed unless you know what your goal is?
21 MR. BECKNER: We are primarily making use of risk, 22 a significant change in risk. I think that we are 23 informally using a lot of the same numbers that people are 24 throwing out in terms of the safety goal, but we have no 25 formal criteria.
) Heritage Reporting Corporation
~/ (202) 628-4888
60
,~
(.) 1 DR. KERR: It is hard for me to know how one knows 2 where one is going unless one has some idea of where one 3 hopes to be.
4 MR. BECKNER: Right now we are looking at the 5 items that contribute significantly to risk. I am sorry, 6 that is the wrong term. The items that are major 7 contributors to the risk, and where we can get major 8 reductions in that contributor. Separately I think that we 9 need to evaluate whether that major contributor is 10 significant, in other words its absolute value. And again 11 that is a judgmental thing. That when we did make a 12 recommendation under the Mark I program that we used cost 13 benefit.
(} 14 15 DR. KERR:
informal, is the approach going to be one such that is the Now under the ground rules formal or 16 core melt frequency is low enough that you really do not 17 worry about containment performance, or if containment 18 performance is good enough that you are willing to accept a 19 fairly high core melt frequency. Because if you are really 20 just looking at risk and that is your principal decision 21 making quantity, it does not really matter a great deal 22 whether you get that from containment performance or from 23 core melt performance.
24 MR. BECKNER: I think from a practical standpoint 25 if the core melt frequency is much less than ten to the
() Heritage Reporting Corporation (202) 628-4888
h
\'
i l 61 f^
(j$ : 1 minus fifth.regardless of the containment performance that 2: you are not going to find anything that is cost effective.
3 That is a practical consideration when.you go to cost 4 benefit.
5 DR. KERR: Yes, I certainly agree. So that would 6 say.that'if you couldiconvince yourself to say that core 7 frequency is ten to minus six that you would be willing to B eliminate containment?
L 9 MR. BECKNER: I will not go that far.
10 DR. KERR: We2', it seems to me that'you are being 11 ' inconsistent.
12 MR. BECKNER: No. It says that I probably could i
13 not justify containment on a cost benefit' basis if indeed 14- the. containment was in. enhanced safety space and'not 15 adequate safety space.
16 DR. KERR: So then your-containment performance 17 criterion is that the containment be there.
18 MR. BECKNER: No. The containment exists.
19 DR. KERR: But you are unwilling to set any 20 performance criterion except you are unwilling to eliminate 21 it. So that means to me that the performance criterion that 22 you insist upon is that there be a containment.
23 MR. BECKNER.: - No. We are dealing with enhanced 24 safety. We are not dealing with the existing regulations or 25 levels of safety.
Heritage Reporting Corporation (202) 628-4888
62 L () 1
~
DR. KERR: You are not using the existing 6 2 ' regulations any time that you use risk analysis.
- MR. BECKNER: No, that is what I am saying.
4 DR. KERR: I am trying;to understand what you.are 5 willing to insist on as a minimum for containment. As far 6- as I can see, the minimum is that it be there.
7- MR. BECKNER: We do not have a containment 8 performance criteria. That does not exist.
9 DR. KERR: I am sorry, you do, because you said.
-10 that you were unwilling to operate the plant without one.
11 And that means to me that the performance criterion of the 12 containment is that it be present.
13 MR. BECKNER: Bill, 1 could give you my personal 14 opinion, but that would not be the view of the agency. I do
)
15 not think that the agency has a view or has a position that 16 has been stated and written down at this point.
17 DR. LEWIS: Bill, one way to answer your question 18 would have been to look at page one which says the program 19 is based on the conclusion to determine whether additional 20 regulatory guidance or requirements are warranted. Negative 21 consequences are not contemplated.
22 DR. SIESS: It is a lot easier to make these 23 decisions if you do not have a policy.
24 DR. LEWIS: Well, we have too many policies.
25 MR. WARD: Well, Bill, there is a requirement that
() Heritage Reporting Corporation (202) 628-1888 l'
,_ 63
\Y' 1 the containment be there.
2 DR. KERR: Are you sure?
3 161. WARD: The general design criteria.
4- DR. REMICK: Does it say that there must be a
'5- containment?
6 MR. WARD: Yes.
7 DR. REMICK: I thought I checked that out six 8 months ago and found that there was no such requirement.
9 DR. KERR: Mark Steller is shaking his head 10 negative. It may not say that there be one but it certainly 11 gives some general guidance.
12 MR. STELLER: This is Mark Steller. I did some 13 research for Dr. Remick six months or so ago and looked for 14 a specific written requirement that there be a containment (O j 15- for reactor plants and I was not able to find one.
16 Obviously the GDC have strong suggestions and implications 17 that one should be there because there are many articles in 18 the GDC.
19 DR. REMICK: I came to the conclusion that it was 20 just like training. There is no requirement in the 21 regulations that a licensee have training programs. There 3
22 is a requirement that they have requalification training, !
23 but there is no requirement that they have training and this l 24 is similar. We just take it for grar.ted.
25 MR. BECKNER: The requirr.ments of what that Heritage Reporting Corporation (202) 628-4888
l 64 lhk s 1 . container should do.
2- DR. REMICK: Like not leak.
3- MR. BECKNER: Whether or not it is there or not, I 4 do not know. Some people might say that it is an implied
'5 requirement. Since it cannot leak, it has got to be there.
, 6- DR. LEWIS: This came up as a very serious issue 7 in the new production reactor, because it was found also 8 that there was no direct requirement for containment,.but it 9 duly announced as its policy that there would be a 10 containment regardless of the logic which was the part that 11 you were emphasizing I think.
12 DR. CATTON: Bill, how did you do the cost benefit 13 for the hardened vent, what did you assume for the liner 14 failure, as you had to do something?
15 MR. BECKNER: The bulk of the benefit from the 16 vent came as a preventive measure preventing core melt.
17 DR. CATTON: Oh, okay.
18 MR. BECKNER: With regard to wher. we did have 19 melt, again like I said we assumed in effect that we would-20 have a decontamination factor of three.
21 DR. CATTON: Even though the liner might fail?
22 MR. BECKNER: Yes. Water laying over the pool 23 would provide scrubbing of fission products.
-24 DR. CATTON: But if you have a liner failure, that 25 will run out the hole, will it not?
(} Heritage Reporting Corporation (202) 628-4888 j
j l
_ _ _ _ _ _ _ _ ___ O
l
. - . -c 65 rm-11 MR. BECKNER: We talked about that.
~
2 DR. CATTON: . So-it is somewhat arbitrary. But if l .-
.3- the, benefit comes'from preventing core melt..
i 4' MR.-BECKNER: The big benefit from the hardened 5 vent was from preventive. .Obviously'the. benefit from the 6 spray.was from whatever it might do to either prevent' liner 7 failure or scrubbed fission products.
B l- 9 l
10 ,
11
~12
.13 0 14 15 16 17 18 19 20 21 22 23 24 25 Heritage Reporting Corporation (202) 628-4888
?
s 66 l 1 MR. BECKNER: First of all, as far as the other 2 boiler. containments, the Mark IIs and the Mark IIIs. ,
3 Obviously the types of things that we recommended'for Mark 4 Is could potentially be useful, and we are looking at them.
5 The major exception to that~is.the hardened' vent.
6 I had a previous slide, and I want to make the point, is 7 that the issues for venting, particularly for Mark IIs, are 8 going to be different from Mark Is. There are several 9 differences'for Mark IIs. First of all, Mark IIs have 10 larger volumes, which is the good news.
11 .The other news is that there is a potential for 12 failure of down comers,.if you do get core on the floor with 13 a Mark II, which gives you a potential for bypass.
- 14 Obviously, one thing may make the need for venting 15 not as great, the other thing may make the desirability to 16 vent a Mark II, particularly after you have vessel failure, 17 undesirable, because there is a potential for bypass of the 18 suppression pool.
19 So these issues are important for the Mark IIs.
20 In addition, there are three different designs of Mark IIs 21 as far as the area underneath the vessel, and so again the 22 issue of venting may be different for each Mark II.
23 So we recognize that the Mark IIs are different 24 from Mark Is and different amongst themselves.
25 MR. WARD: I have not read the draft paper on Mark
.1 Heritage Reporting Corporation !
\[ (202) 628-4888
k '
67 1 II. But -- don't take that down yet.
(s)
~
2 Are the improvements for the Mark II you are 3 suggesting primarily in the area of preventing core melt, as 4 they were for Mark I?
5 NR. BEC'KNER: It is both. And I think it is the 6 things that we are looking at, whether or not we will 7 recommend them, find them effective or so forth. It is in 8 the area of both.
9 Again, we will be looking at the alternate water 10 to both the vessel and the spraye, and the ADS reliability, 11 which impacts both mitigation and prevention.
12 MR. WARD: What do you mean by the last comment 13 there?
14 MR. BECKNER: Okay. I guess what I am doing here O 15 is the ACRS had specifically recommended the second bullet 16 and so what I am indicating is that yes, we will be 17 considering that in addition to the other items.
18 Maybe that sentence should be more consistent, 19 rather than consistent.
20 MR. NARD: Yes. Because there were a couple of 21 other things in that letter, too. I think one of the points 22 in the letter was that the containment performance 23 improvement program kind of finessed the issue by, seemed to 24 be trying to finesse the issue by concentrating on 25 imortvements to the prevention . numbers, rather than really
/~% Heritage Reporting Corporation k) (202) 628-4888 1
l _ _ _ _ _ _ _ __________ _
68 cx
(-) 1 on improving the containment performance.
2 MR. BECKNER: I think we got into that problem 3 because of the characteristic of the boiler, in that when 4 you try to fix the containment you ultimately fix the vessel 5 prevention more.
6 All of our recommendations, with the exception of-7 vessel injection, impacted mitigation. But they tended to 8 impact prevention on a greater basis.
9 MR. WARD: Okay.
10 DR. REMICK: I suggest we try to move along.
11 MR. BECKNER: Yes. Let me just briefly complete 12 the summary.
13 As far as the Mark IIIs, on one issue that has
T 14 raised is the benefit of backup power to the hydrogen (V
15 igniters, and so we will be trying to evaluate that.
16 For the PWRs on both the ice condenser and the 17 large drives, one obvious issue is direct containment 18 heating.
19 If you look at the latest 1150 results, that 20 contribution to risk or te containment failure has gotten 21 very, very small based on pt'.marily the assumption or the 22 calculation that the vessel vi.1i be depressurized before ths 23 bottom head melts out, that the surge line or some of the 24 steam generator tubes will melt.
\
25 So from the 1150 standpoint, direct containment l l
I
'g,) Heritage Reporting Corporation l (202) 628-4888 l 1
i
ts 69
()I 1 heating is no longer a significant risk. We still are y- 2 looking at' direct containment heating, however. -What we are p.
~
3 doing is we are working with the accident' management people 4 in this area. Accident management is 'looking at the 5 depressurization strategy to try to prevent direct 6 Leontainment-heating. We are making use of their results and 7 in fact while they are doing primarily the vessel 8 calcu".ations, we are looking at what the containment.would 9 do f:Jom the source terms tnat they get out of the vessel, 10 _the steam and hydrogen source terms.
11 DR. CATTON: Isn't it kind of a problem if the 12' steam generator tubes melt?
l 13 MR. BECKNER: That's kind of a problem. That is 14 right.
15 And we have identified that as a, or at least 1150 16 has identified that as a relatively high risk, I believe,-
27 not a high frequency but a high risk.
18 DR. SHEWMON: Would you state again what ha 19 reduced the concern for DCH7 20 MR. BECKNER: The calculation that either the 21 surge line will melt and depressurize the vessel or-the 22 tube, the steam generator tubes will melt and depressurize 23 the vessel before the bottom head melts out.
24 DR. SHEWMON: Since both of those components would 25 fail by creep long before they would melt, I almost wish you Heritage Reporting Corporation (202) 628-4888
70
- 'i
/]~; l
~
wouldfuse that1 terminology.
2 MR. BECKNER: I'm sorry. Creep is the right term.
31 DR.=SHEWMON: Okay. :Thanks.
4 MR. CARROLL: And you speak of bottom head melting 5 out. Does that encompass the instrument _ tubes?
6 MR. BECKNER: There is a-wide range of speculation 7 on how the: bottom head might fail, from melting of tubes.to-B creep rupture or the whole bottom' dropping out.
9 MR. CARROLL: But what you are looking at.'now is
~0 just you would depressurize before any.of'those failure 11 mechanisms.
12 MR. BECKNER: 'What 1150 found, and that is 13 supported'to a degree by'the calculations chat the accident
() 14 ' management people are doing, that-the surge line is going to 15 fail.
16 DR. CATTON: I believe this is what'the EPRI 17 studies found four or five years ago. I'm glad to see you
]
18 are coming around.
'19- DR. KERR Don't say found. Say concluded.
20 DR. CATTON: Concluded.
21 MR. BECKNER: That didn't happen at TMI, though.
22 And there may be good reasons for that.
23 MR. CARROLL: The bottom head didn't fail, either.
24 MR.- BECKNER: Right. But there is no indication L 25' of any high temperatures in the upper head of the vessel.
Heritage Reporting Corporation (202) 628-4888
71
) 1 MR. WARD: It's full.of water, for one thing.
2 MR..BECKNER: That's true, because they sat for a 3 long time one third full or so.
4 The only other things I want to say as far as PWRs 5 with the ice condensers, because of the smaller volume 6 containments, a concern is station blackout, backup power to 7 the igniters and the fans and so forth are being looked at.
8 The large drives, again the concerns there are much less.
9 We are looking at hydrogen in large drives simply because we 10 have generic issue, Generic Issue 121, for hydrogen control 11 in large containments.
12 That concludes, I guess, what.I want to say.
13 Oh, let me throw up this last slide real quick.
14 This is just an indi scion of some of the specific 15 coordination we are doing. As I indicated on the
- 16. depressurization issue, we are primarily making use of the 17 accident management people's work.
16 Steam generator tube rupture was-highlighted as a 1
19 major concern. W:a are not doing anything specific as far as l
l 20 the weaknessos or degradation of steam generator tubes.
21 That has ongoing work elsewhere in NRC.
1 22 1150 again, for some of the PWRs, highlighted 23 interfacing system LOCAs, as some of the dominant risk 24 contributors.
25 There is a generic issue, and also because of the
,f3 Heritage Reporting Corporation (202) 628-4888
72 '
(). 1 differences in systems it is our initial reaction that this 2 problem would best be addressed in the IPEEE looking at-the' 3 specific systems.
4 Again I believe this is an ice condenser issus.
5 ,Your spre.ys may come on and deplete, during small break 6 LOCA,' ' deplete your water storage before you inject ~it in the 7 vessel.
8 That in potentially a strategy or a procedure that 9 can fix that.
10 So that is being looked at under the accident 11 management. What I am trying to indicate here is that we do 12 have a lot'of people working on this overall severe accident 13 issue. All the issues are.very inter-related, and we are 14 trying to both coordinate and not duplicate effort, and talk-15 to each other.
16 That's all my presentation.
17 DR. REMICK: Okay. Any other questions, comments 18 on the subject?
19 MR. CARROLL: You mentioned backup power supplies 20 for igniters.
21 MR. BECKNER: Yes.
22 MR. CAPROLL: I guess I am still pushing the idea 23 that somebody ought to be smart enough to invent a reliable 24 catalytic igniter. Is there any real work going on in that 25 area?
() Heritage Reporting Corporation (202) 628-4888
f k
73 .l 1 ' MR . BECKNER:- I'm not sure currently. I know 2 Sandia had looked at it some time ago. And there were-3' problems I think at that point in time. I don't know of any 4 ---
5 MR. : CARROLL: Catalyst poisoning?
6 MR. BECKNER: I think that was the problem. Also,.
7 they have to typically stay alive in a steam environment for 8' a-long time.
9 DR. SHEWMON: I can't imagine it would be anything 10 other than some hypothetical poisoning, because that stuff 11 ought to be pretty stable in steam.
12 I.mean, if there is water condensed on it, then, 13 to the gasket, to the surface, I don't know about that.
'14 Under water, how well would --
- O ' 115 MR. CARROLL: It wouldn't do very well.
16 DR. KERR: We should not subject Mr. Beckner to 17 .this discussion, it seems to me.
.18 DR. REMICK: I thought he was enjoying it.
19 DR. KERR: I say we should not subject you to this 20 sort of discussion, it seems to me.
21 MR. BECKNER: I guess the only thing I would like 22 to say is that we are not asking for any formal response 23 from the Committee, but any comments that you may want to
- 24 provide, informally or otherwise, why we will certainly l
25 welcome them.
Heritage Reporting Corporation O* (202) 628-4888
1
. ' 74
/~5. i k- 1 DR. 'IGEMl: I will repeat my suggestion that you 2 .give some thought.to developing performance criteria. That )
i 3 is my only comment.
4 MR. WARD: Okay. Thank you very much, Bill. And 5- Mr. Chairman, that is all we have on this topic.
6 DR. REMICK: -All right. Thank you very much. I'm 7 sorry. Go ahead.
8 DR. SIESS: How much heat ' cur energy does it take 9 to set off the hydrogen? q 10 If you lit a match in there, it wouldn't go? i l
11 MR. CARROLL: It depends on a lch of things. It'
- 12. depends <xi concentration, it depends on the amount-of water 13 vapor present and so forth.
-( ) 14' At some of the low concentrations th9 Staff is 15 worried about, I think we heard a presentation a couple j 16 ' months ago where they were trying to figure out just how 17 much energy it would take at low concentrations.
18 Would, for' example, the electrical arcing us a 19 result of the failure ' of a power supply c f i;ome sort -- ,
)
20 DR. SIESS: I was going to have a station }
21 blackout,-so I couldn't use that.
22 But if it is a low enough concentration, how much H23 of a challenge is the burning to the containment? With a 24 high concentration, you have a possible detonation.
I 25 MR. CARROLL: Yes. And you can, even at lower i
i l
Heritage Reporting Corporation (202) 628-4888
l
. 75 1
- 1 concentrations, if you put enough energy.into it, you can
- 2. have detonation.
3 DR. SIESS: When you are talking about a power i
4 supply for the igniting, you are talking about how many 5 watts you got of supply?
6 DR. KERR: You are talking about kilowatts.
7 MR. CARROLL: When I talked about power supply I 8 was. thinking of arcing resulting from say the failure of a 9 junction box --
10 DR. SIESS: When you are talking about auxiliary 11 power supply, you are talking about kilowatts?
12 MR. CARROLL: Oh, yes. Yes, these are glow plugs.
13 These are diesel glow plugs that they are using, I tl k.
(} 14 DR. SIESS: Spark plugs?
15 MR. CARROLL: What?
16 DR. SIESS: Spark plugs wouldn't work?
17 MR. CARROLL: It's a complication.
18 DR. KERR: They would ont work very well in water 19 probabli You'd get breakdown of the insulation.
20 DR. R3 MICK: Okay, gentlemen, mcy we proceed?
21 DR. SIESS: The more I hear, the more confused I 22 get. Because if you can't set it off deliberately, what is 23 going to set it off accidentally?
24 MR. CARROLL: Well, a hot filament is a lot less 25 intense energy source than the electrical arc resulting from Heritage Reporting Corporation (202) 628-4888 I
r:
76
- ( [ 1 a 12'kv terminal arcing over, or whatever.
-2 DR.-SIESS: You know, we are going to have a great 3 difficulty igniting the stuff and the reason we are igniting 4 it because we are afraid.it will be ignited _by something 5 else.
6 So one is difficult and the other one is easy.
7 DR. REMICK: All right, gentlemen. I would like 8 to turn to Item 7 on our agenda, Subcommittee Activity 9 Reports.
10 And I would like to ask Mr. Michelson to fill us -
11 in on the subcommittee meeting that was held I believe on 12 Tuesday, on ACRS bylaws. -
13 (Whereupon, at 11:28 a.m.the lunc?. recess was 14 taken, the meeting to resume at 1:00 p.m. on the same~ day, 15 Thursday, July 13, 1989.)
16 17 18 19 20 21 22
- 23 24 25 Heritage Reporting Corporation O* (202) 628-4888
-77 1 AEIEBHQQH EElE1QH 2 1:00 p.m.
3 DR. REMICK: The next item on our agenda for this 4 meeting is a' discussion of the reactor pressure vessel 5 integrity.
6 The Subcommittee Chairman is Dr. Shewmon. In 7 portions of this session we will discuss proprietary 8 information so we will have to close the meeting at that.
9 appropriate time.
10 DR. SHEWMON: This is under Tab 5.
11 We had a couple meetings on this. One was the 12 subcommittee meeting that is mentioned there. Subsequently, 13 the NRR people did not make our subcommittee meeting. There 14 was a separate meeting in which I met with some people from O 15 NTR.
16 They indeed will take part in meetings here, and 17 that is the part that is proprietary. Following that is a 18 subcommittee report which I would like to read to you to try 19 to create a background for this.
20' Appendix G vf 10 CFR 50 addresses fracture 1
21 toughness requirements for ferritic material like the 22 reactor pressure vessel.
23 This comes up in a couple different ways. One way 24 that we don't talk about too often is how much toughness 25 does the steel have even you are above the transition
(^)
N/
Heritage Reporting Corporation (202) 628-4888
~
w- -
. . _ l
L
)..
78
- i. 1. temperature.
2 In particular, that is called upper-shelf energy.
3- The code says or the appendix says, " Reactor vessel belt 4 line materials must have a Charpy upper-shelf energy of no 5 less than 75-feet pounds initially and must maintain an 6 upper-shelf energy throughout the life of the vessel of no 7 less-than 50-foot pounds unless it is demonstrated.in a 8 manner approved by the Director of NRR, that lower values of.
9 the upper-shelf energy will provide margins of safety 10' against fracture equivalent to those required by Appendix G 11 of the ASME Code.
12 And compliance or noncompliance or indeed defining-13 when you comply with that is the mainLpoint of,the
'14 discussion today.
)
15 If you don't meet that criteria -- and as you will 16 see, there are several plans that don't have it for some 17 years, at least by conservative criteria -- then there are f
-18 three things that must be done that I paraphrase here.
19 Yoa must do an inspection.
20 You'must look harder at radiation effects and l
21 damage in these, materials.
22 And then an analysis must be " performed that 23 conservative 1y demonstrates, making appropriate allowances 24 for uncertainties, the existence of equivalent margins of 25- safety for continued operation."
Heritage Reporting Corporation (202) 628-4888
1 79
() 1 Then finally I point out if indeed the procedures 2- of'Section V.C do not-indicate the existence of an 3 equivalent safety margin, the reactor vessel belt line may,
'4 -
subject to approval of the Director of NRR, be given a 5 thermal anneal to recover the fracture toughness of the 6 material.
7 Now the upper shelf energy decreases with fast 8 neutron exposure. There is a group of about 17 PWRs with 9 vessels manufactured by B&W, for themselves and for 10 Westinghouse, which have the potential for exceeding this 11 limit.
12 This stems from the fact that they were made with 13 copper coated weld wire and were made with a flux which
' 14 gives good radiographs, but low upper-shelf energy.
15 In your handout, I trust, is a copy of the 1987 16 memo requested by Tom Murley which lists the plants in which
- 17. there might be a problem by the end of life, and suggesting 18 that by the conservative requirements of Reg. Guide 1.99, 19 five of the vessels may have been below the 50 foot peunds 20 limit since at least 1966.
21 The concern about 50 foot-pounds is not an idle 22 one since there is some evidence of icw toughness failures 23 in other applications of steel with Charpy upper-shelf 24 energies less than 50 foot pounds.
25 History does not record how much less than 50 Heritage Reporting Corporation (202) 628-4888 l
_- ____m
80
.() 1 foot pounds.
2 Also, as.you know, the design basis of the entire 3 reactor safety system is premised on having a reactor
- 4. pressure vessel of such high quality that one does not have 5 to postulate its rupture in any of the accidents that are.
6 considered.
7 The potential for exceeding the 50 foot pounds 8 limit was foreseen fifteen to twenty years ago and it became 9 GSI A-11.
10- This issue was declared resolved in 1982 based on 11 the publication of NUREG 0744, which argued that elastic-12 plastic fracture mechanics could be used to show that a 13 quarter thickness flaw would be stable at the design 14 pressure and still have a margin of safety.
.O 15 Unfortunately, the " resolution" did not spell out 16 just what would constitute an acceptable demonstration for 17 NRR.
18 In the intervening seven years, NRR has not 19 decided what they will do about this. Somatime after the 20 issuance of NUREG 0744, Rev. 1, mygbe in 1903, the catter of 21 what the accep2 mace criteria should be was referred to 22 Section XI of the ASME B&PV Code.
23 They have baen working on it ever since. And 24 there is still no accepted means of proceeding, though we 25 will hear today about some tentative criteria.
I O Heritage Reporting Corporation (202) 628-4888
_ _ _ _ _ _ _ _ _ _ _ __ l
81
' ( ); 1- A'B&W owners group was started tocok into the
- 2 low upper-shelf problem at least a decade ago.
p, 3 Not all of the owners of B&W reactors chose to 4 join this program'so the results are proprietary so as to 5 keep'them from those outside the group.
6 It developed that the licensees with the worst 7 problems (projections of lowest Charpy energies) were the 8 owners of some Westinghouse reactors.
9 Efforts to get a Westinghouse owners group 10 organized to look into this failed and in the last few years 11 the plants with particular problems have joined the B&W~
12 group.
13 My impression is that the OG has devoted much of 14 their effort to gathering additional evidence of the 15 fracture toughness of the material after neutron radiation.
16 ' T hr.'c was the second criterion.
17 You may recall that the surveillance data in the 18 B&W pldnts isn't as good as in some other becauue in one or 19 mere of the lead plants, the surveillance packages fell off 20 the wall of the RPV.
21 The NRC research program in this area has been 22 increasing in the last several years to where it is now a 23 few million dollars a year. This deals primarily with two 24 topics:
25 (1) Better definition of the effect of fast Heritage Reporting O Corporation (202) 628-4888
82
/
! ) 1 neutron irradiation on these welds, and
- 2. (2) Figuring out how to perform the elastic-3 plastic fracture mechanics analysis suggested in the NUREG 4 0744.
5 One gets the impression that many people are 6 working on the problem, but that the definition and 7 implementation of an acceptable solution is difficult and 8 controversial.
9 In the meantime, the date for the definition of 10 acceptable criteria by NRR is still undefined. In 1980, 11 when the " resolution" of this problem was presente<1 to the 12 Metals Components Subcommittee of the ACRS, we were told 13 that if the energy value fell below 50 foot pounds, the 14 regulations in Appendix G,Section V, given above, would be s
15 implemented.
16 Of these, there has been a regular ISI inspection 17 for these welds, one hopes with the best techniques 18 available, but for 1981 or 1982 inspections, it isn't real 1
19 clear how good they were.
20 Additional fracture toughness data has been 21 obtained.
22 various competent groups are trying to do an 1 23 elastic plastic FM analysis, bit it is a difficult problem.
l j 24 No licensee has proposed to anneal their vessel, primarily 25 becaur I..ey hope to meet the NRR criteria without doing Heritage Reporting Corporation O- (202) 628-4888 I
l L_ _- _-
83
() 1 that.
2 We had a subcommittee meeting on this matter on 3 June 20th. I mentioned that to you before. And we heard 4 from RES, their contractors, and Neil Randall, who has been 5 the NRC representative on the ASME Sect, ion XI Group looking 6 for a resolution to this problem.
7 Then I go on to say that the NRR feels they cannot 8 talk with us in an open meeting because of the proprietary 9 nature of the information involved, and because there is 10 some litigation concerning one plant; that is Turkey Point 3 11 & 4.
12 This is something which I feel mildly 13 uncomfortable about. I think after listening to the staff, 14 and they believe that, probably with a good basis, that 15 there is some margin there and quite possibly an acceptable 16 margin.
17 But it surprised me some to stumble on this, that 18 it is there and perking away and progress is not as rapid.
19 The presentation that we have this afternoon 20 consists of three parts. There is the research program, the 21 regulations and history and RPV integrity.
22 The staff suggests that we interchange the order 23 of the first two item: there so that Randall comes first and 24 then Mayfield with the research program.
25 And then finally Barry Elliot will discuss what Heritage Reporting Corporation Os (202) 628-4888
t 84 )
- l' NRR is considering as satisfactory criteria for continued 2 operation.
3- Any questions? l i
4 (No response) 5 Good.
6 Do you have any comments you want to make?
7 DR. CATTON: No. ,
8 DR. SHEWMON: Fine.
9 -Let's begin then.
10 MR. RANDALL: I am Neil Randall.
11 I will add to Professor Shewmon's introduction a 12 few more items to try to get you up to speed.
13 First, the question: tthere did we get 50 foot-()
v 14 pounds in the first place? It is almost lost in antiquity, 15 I am afraid, but there is one bench mark, one cite.
16 In a 1969 AEC basis document, it was stated that 17 there ought to be some minimum upper-shelf toughness. And to 18 get at a value for that, they postulated that they should 19 have enough toughness to show stability of a through-wall 20 crack that was twice as long as the wall thickness.
21 So that means a 20-inch crack in a ten-inch wall, 22 that being the thickness belt line they conceived then.
23 They simply did a linear elastic fracture mechanics analysis 24 to get the required K-1-C.
25 And then converted K-1-C to upper-shelf energy
( Heritage Reporting Corporation (202) 628-4888 1
,i 85
_ ./' 4(^T l' using a correlation that had been published,'actually 2 independently, by Marsin and Rolfe. Then there was another-3 one by Novack. This may have been the Rolfe-Novack 4 correlation that was used.
5- It is not quite clear in the document.
61 Anyway, that is the most quantitative source and 7' origin of the number 50 foot pounds that I have found.
8 In 1977, a similar kind of analysis was done 9 except they used a. quarter T' flaw, which you recall is:one 10 and a half times the wall thickness in length, a semi-11 elliptical flaw a quarter of the way through the wall.
12 Same. sort of stability calculation using Marsin 13 and Rolfe. And there, because the crack size' differs with
() 14 wall. thickness, they found they needed values ranging from-15 33.5 to 45 foot pounds for the range of thicknesses-that
-16 were represented in the PWR vessels that were susceptible to 17 this.
18 And so that gave us the warm feeling that we lived-19 with through the '70s, I would say. But 50 foot pounds was 20 not a drop-dead value.
21 By 1977, however, there was an effort by Paul 22 Parris for us to do a more sophisticated elastic-plastic 23 analysis.
24 He came up with something he called a tearing 25 modulus. And this task A-11 was formed in 1980 to address Heritrge Reporting Corporation (202) 628-4888
l 86 I
[~D 1 the issue in a more sophisticated way.
x/
2 As Professor Shewmon said, NUREG 0744 described 3 the use of JR curves as the right material property to use.
4 And if I can keep from miring down in too much 5 detail, let me show you a schematic JR curve. J is the 6 tearing resistance. You notice its units are in pounds per 7 square inch.
8 So it is the energy to tear in this area the 9 material by the crack. Or, if you prefer, it is the force 10 required to advance a unit length of crack, a crack-driving 11 force.
12 A JR curve is a plot of that value versus the 13 advance of the crack, Delta A.
14 When they test a fracture toughness specimen, O 15 generally a bent specimen with a pre-existing crack, they -
16 get load deflection data.
l' From that you calculate J. And from other 18 measurements you calculate Delta A. And you get a curve of 19 J material.
20 From analysis, they can get a curve of J applied 21 for the pressure and thermal stresses that act on the 22 vessel. That plots as a nearly horizontal line.
23 of course, it increases slightly with crack 24 length. And the mathematical . solution of the problem 25 consists in finding this point.
(' Heritage Reporting Corporation
\-)
m (202) 628-4888
. ]
87
'1. The conditions of which the ordinate and the slope 2 of the J material in J-applied curves are equal. That is -l 3 -essentially what NUREG 0744 did. It said, you know, get 4 this mind of material property. Go through this kind of
'5-
' analysis.
L 6 And they spent.a lot of pages describing how to 7 solve the tw1 equatione for this. That turns out to be a 8 messy problem.
9 You will see more JR curves, real ones, in a 10- moment.
11 When that task was nearing completion, however, 12 there was a lot of controversy about, having done that l
L 13 analysis, what was the proper criterion for acceptance.
14 Then that task was thrown to this Section 11 Code 15 committee to ad'irees the question of margins.
16 Curiously enough, it was not until 1983 when 17 Appendix G was amended to include e specific 50 foot-pounds 18 requirement. Before that, it had been in there because we 19 required them to measure shift at 50 foot pounds.
20- And if you didn't have 50, of course, you didn't 21 have a shift number.
22 But that is when the specific requirement that 23 Professor Shewmon read off got in there, including this 24 proviso that lower values could be accepted if you could 25 show margins of safety equivalent to those required by O aerie ee a-verei 9 correr eie-(202) 628-4888 l
h _ _ _ _ _ _ _ _ _ _ _ _ _ _
88 1' Appendix G.
2 Well, by 1985,.the Code Committee said that L 3- tentative criterion were these. The words_" equivalent l
4L margin", if you track through all the regulation and Code 5 statements, came out that you needed a factor of 2 on-6 pressure.
- 7. .And the pressure for -- you remember, Appendix G.
8 is only in normal and anticipated operational occurrences.
9 Code language, Levels A and B, for Level'B, the pressure 10 given in the Code is that that defines how you size safety 11 valves.
12 And it says, " Size thc.n so that the pressure will 13 not exceed 10.per cent above. design pressure."
14 So that is the Level B pressure. If you multiply 15 that by two and add the effects of the thermal stress, apply 16- that to a vessel with a quarter T flaw, you then get a 17 required J applied.
18 Some problems developed on that.
19 The people who were doing experimental work got 20 into arguments about how to calculate J from the test 21 specimens. And there were other problems of an analytical 22 nature.
23 Let me stop there and let Mike Mayfield tell you 24 what research has been along those lines, to explain what 25 this means.
Heritage Reporting Corporation (202) 628-4888
i l
89
( ]) 1 Then I will come back and show you our attempts to 1
2 vrite an alternative criterion that finesses some of the 3 problems, 4 MR. MAYFIELD: My name is Mike Mayfield.
5 I am going to tell you a little bit about our 6 research program on this low upper-shelf vessel issue, 7 Appendix G of 10 CFR 50 and Appendix G of Section 8 III of the Code, taken together, provide some assurance of 9 protection against both brittle and this low energy ductal 10 fracture.
11 The brittle fracture analysis that we talked about 12 from Appendix G is a linear elastic fracture mechanics 13 analysis that uses a quarter T flaw that is six times as s 14 long as it is deep.
15 And this is the criterion: two times the stress 16 intensity due to the membrane stress, which is ordinarily 17 the pressure, plus the stress intensity factor due to the 18 thermal stresses, has to be less than a reference fracture 19 toughness curve. '
20 The low energy ductal fracture analysis is the 21 thing that is required if you fall below 50 foot pounds on 22 the upper-shelf energy. It is also the thing that has 23 caused the most stomach acid over the last several years.
24 To perform that as described in NUREG 07744, it 25 requires an elastic-plastic fracture analysis. Now what are
(~) Heritage Reporting Corporation k_/ (202) 628-4888
[.
90-A.
52 1:
-the_ problems here?' What.causes us to go off and research 2 this issue?L 3 In the linear elastic fracture mechanics analysis,_
4 -we are primarily concerned about shape changes for the-5 reference fracture toughness curve and for the K-1-C curve.
6 'It is a similar curve that is used in Section 11 of the 7 Code.
8 We are worried about changes in the shape as well 9 as changes in the position due to irradiation. The elastic-10 , astJc fracture mechanics analysis, the concerns are a 11 little more basic.
12 It ties back to what we are going to use as an-13 evaluation criteria. Are we going to tie it to flaw
() 14 -initiation or are we going to tie it to flaw instability?
15 Those are some fairly fundamental questions. What 16 are the evaluation criteria? How do you know when you have 17 an equivalent margin?
18 Then we get into details of the analyses, details 19 on the material properties. You are going to hear a little 20 bit more about this this afternoon. I think Barry is_ going 21 to talk about some of this in the closed session.
22' And of course, the validation experiments. We l 23 need some bench marks.
24 We have put together a research program. I don't 25 intend to spend much time on this slide, simply to show you Heritage Reporting Corporation (202) 628-4888 l
L l
t '
91
{ 1 in a flow chart form.
2 The research program deals with irradiation 3 ' damage', the analysis _ activities, material properties-and 4 validation experiments.
5 We will talk more about these boxes as I go along.
6 The intent is to end up with fully validated procedures to 7 use by the staff in determining acceptance criteria as well 8 as a basis for evaluating utility analysis.
9 DR. REMICK: Is this an existing program now?
-10 MR. MAYFIELD: Yes, it is.
11 DR. REMICK: Where is it being conducted?
12 HR. MAYFIELD: Several different places.
13 The irradiation damage and a good part of the 14 analysis work is done under the heavy sections steel 15 technology at Oak Ridge, the HSST Program at Oak Ridge.
16 We have got some work being done by the David-17 2aylor Research Center out here at Annapolis. Several 18 universities are involved.
19 DR. REMICK: Thank you.
20 MR. MAYFIELD: I would like to look now first at 21 the irradiation damage analysis or the irradiation damage-22 research.
23 Looking at the K-1-C curve simply because it is 24 the slide I had. But the concern is the same. You start 25 with a fracture toughness curve versus temperature.
O Heritage Reporting (202) 628-4888 Corporation i
92
() 1 Whether it is K-1-C or K-1-R, it is a function of 2 temperature due to irradiation; the curve shifts over. And 3 in fact, a question raised by Mr. Etherington some years ago 4 was, "Does it also change shape? Does the curve lay-over?"
5 We know that Charpy energy curves tend to lay over 6 due to irradiation. Did the fracture toughness curves also 7 lay over?
8 We find that indeed they do. That is one of the 9 outcomes of some irradiation studies that I will mention 10 very briefly in just a minute.
11 The question is: does the shape change 12 differently for these low upper-shelf materials than it does 13 for high upper-shelf materials.
- 14 We are going to be looking at that some in some 15 subsequent irradiations. But this really chara:terizes what 16 we are concerned about in the linear elastic fracture 17 mechanics analysis: the change in position.as well as shape 18 of these curves due to irradiation.
19 In the elastic-plastic fracture mechanics 20 analysis, these are these JR curves. Maybe the best thing 21 to do is slide this up a ways.
22 (Pause) 23 Crack driving force varsus change in crack length.
24 These upper curves are for unirradiated, low upper-shelf 25 materials. Due to irradiation we see a significant decrease Heritage Reporting Corporation
./'}
\-- (202) 628-4888
l 93 (G_) 1 in the initiation value as well as a significant lowering of 2 the slope.
3 Both values are used in the tentative criteria 4 that are being considered. For an initiation based 5 criterion, clearly you are more concerned down in this 6 region.
7 When we are talking about flaw instability, you 8 are concerned about the change in slope.
.9 Now just to give you a feel for what we are 10 talking about, this T average is related to the slope. That 11 decreases by some 62 per. cent due to irradiation.
12 These wers oat at one times ten to the nineteenth 13 neutrono per square centimeter.
14 J-1-C decreases by some 31 per cent.
15 So the point being that the slope of the curvo 16 decreases more but it appears to be a more sensitive measure 17 of irradiation damage.
18 It also complicates your life. The fact taat 10 that elope is decreasing significantly complicates your life 20 a bit as you are going to do the instability analysis with a 21 limited data set.
22 The irradiation damage research, we have conducted 23 so far seven irradiation series. We have three more 24 planned.
25 The second and third irradiation series were
() IIeritage Reporting Corporation (202) 628-4888 l
1
_ _ _ _ - - - _-- - i
4 94
,m i) s_ 1 performed using these low upper-shelf wells. They were 2 donated by Babcock and Wilcox.
3 They were irradiated by Oak Ridge in the reactor, 4 I believe. They were tested in a number of places; well, 5 principally at University of Buffalo's facilities by bEA, 6 Materials Engineering Associates.
7 The data I just showed you were generated as part 8 of the second and third irradiations. The fourth 9 irradiation looked at fracture toughness changes, 10 principally the linear elastic fracture mechanics 11 considerations for state of the art, relatively high 12 fracture toughness wells.
13 The fifth and sixth irradiation series look at 14 high copper content, high upper-shelf wells. These two
}
15 irradiation' series are the ones that are telling us that 16 indeed for high upper-shelf materials we see not only a 17 change in the position of the curve r the shift, but also its 18 shape changed.
19 The seventh irradiation deals with stainless 20 steel.
l 21 The eighth, ninth and tenth irradiation series all 22 look at lower upper-shelf materials. The eighth 23 irradiat'on, we will have to make a well to use in that 24 irradiat' a series.
25 But it will be very similar to the fifth and sixth
() Heritage Reporting Corporation (202) 628-4888 L _-__ .-
1 95
,\
1 combined where we are looking at curve shift as well as
()
2 shape change.
3 The ninth irradiation series will use the same 4 material as the eighth series but will look at the effect of 5 annealing on thick sections.
6 There is some hint that there is a difference 7 between annealing Charpy specimens and annealing thick 8 section. The response may be a bit different.
9 The tenth irradiation series looks at both linear 10 elastic fracture mechanics considerations and the elastic-11 plastic for the weld that was removed from the Midland 12 reactor.
13 ,
This is a cancelled Babcock and Wilcox plant. It 14 was not only cancelled; it was abandoned. Gave the utility
\_/
15 a particular tax status.
16 It was a B&W fabricated vessel. The major 17 fabrication wells are circumferentially oriented wells. It 18 is a ring-forged vessel so the welds of interest are 19 circumferential1y oriented.
20 They were made using a Linde AT flux and copper-21 coated wire so you get a fairly high copper concentration.
22 We expect that the unirradiated Charpy energy be 23 somewhere between 55 and 80 foot pounds.
l 24 The particular combination of flux and weld wire 25 used in the Midland vessel as identified by Babcock and l
Heritage Reporting Corporation f]~- (202) 628-4888 l
{
i L___-__-____ -
96
.1- 'Wilcox WF-70', we find.that that particular weld wire will be-2 the controlling material in several plants.
3 'So it is of interest. It is not just a research 4 weld. It is a very practical weld.
5 Sir?
~
6- DR. SHEWMON: I. re:.iember a story one timo about- a ~
7 boy who bragged that his father had Washington's-original-8 hatchet that he cut down the cherry tree with. The handle 9 had been replaced twice and the head once, but it was still 10 the original hatchet.
11 (Laughter) 12 DR. SHEWMON: On this WF-70, was that one heat of-13 steel that they still have significant quantities.of or how
- 14 closely back to what was used in these vessels that'are 15 fifteen to twenty years old is that WF-70?
16 MR. MAYFIELD. .The WF-70 is a designation that is 17 for a particular heat cf wire and flux combination.
18 There is WF-70, WF-67.
19 IV: SHEWMON: So this is the same heat?-
'20 MR. MAYFIELD: This is identically the same heat 21 of wire and same lot of flux.
22 DR. SHEWMON: Okay.
23 MR. MAYFIELD: So for any weld that is identified
-24 as WF-70 in any of these plants, if it says WF-70, it is the 25 same heat of wire and the same flux that we have out on the Heritage Reporting Corporation (202) 628-4888
97
- 1. . ' Midland vessel.
2- DR. SHEWMON: The steel wouldn't change and 3- hopefully the chemistry of the flux wouldn't change much 4 either, is'that right?
5 MR. MAYFIELD: Right.
6 DR. SHEWMON: Okay.
7 MR. MAYFIELD: The weld was removed by Babcock 8 and Wilcox under contract to the EPRI NDE Center. There'are 9 a number of us now that are buying that material back from 10 the WDE Center.
~
11 It has been maintained under very closely 12 concrolled, quality assurance provisions. So that we have 13 some traceability.all the way back to the fabrication stage..
14 Under the HSST Program, we are getting about forty
-15 linear-feet of the weld initial work starting. Actually it-
.15 is ongoing.now. It looks at chemistry and the unirradiated 17 . properties.
18 All the work that is ongoing now at the NDE Center 19 is very detailed,. extensive, nondestructive evaluation. The 20 NDE Center contractors are involved as well as Steve-Doctor 21 from Pacific Northwest Laboratories is using the SAFT UT 22 technology for us, looking very carefully at these welds.
23 We have both the belt-line weld and the weld from 24 the nozzle. So we've got quite a bit of this material that 25 we are getting to look at and look at in a very detailed O Heritage Reporting Corporation (202) 628-4888 i
___________a
r 98.
) 1 ' manner to try and improve our understanding of the initial 2 flaw distribution in these welds.
3 What else are we doing with it? ,
i 4 We are looking, going to look very carefully at 5 the analysis of both local and global copper content and 6 variations in that content.
7 Values reported will range from .35 to .49. Some 8 people say well, the number can be even higher, the point 9 being there is a fairly wide variation in reported copper 10 content for the WF-70.
11 It varies through-the-wall thickness as well as 12 around the circumference. The copper thickness varied 13 because the wire was just dip-coated so you get quite a 14 variation in copper.
(V")
15 DR. SHEWMON: This is a question for you, if you 16 know it, or Neil maybe.
17 But is the increase in the rate of shift still 18 going as rapidly as one goes up from say .4 to .5 copper?
19 MR. RANDALL: No.
20 The copper effect levels off.
21 DR. SHEWMON: Okay.
22 Thank you.
23 MR. MAYFIELD: Okay. j i
24 This wide range in copper is going to require a l 25 statistical approach to understanding the results. That is 1
) Heritage Reporting Corporation l (202) 628-4888 I
l l
99 '
/'~'T
(_/ 1 oae of the confusing factors in some of the earlier 2 irradiation series where we did not have a good handle on 3 what was happeniug.
4 We now know enough to treat this much more 5 carefully and using a statistical approach. .
6 We are going to be doing extensive unirradiated 7 characterizations to determine the initial RT NDT for this 8 material as well as the Charpy upper-shelf.
9 We talk about this Charpy upper-shelf number like 10 it is gold and we really do have a handle on it. There is 11 quite a wide variation in Charpy energies, Charpy test 12 results on the upper-shelf.
13 So we are trying to define exactly what is a good
(')
%J 14 number for this particular weld on the upper-shelf.
15 The irradiation series, we are going to be looking 16 at the ductal tear resistance, these JR curves, as well as 17 the K-1C crack initiation and crack arrest curves; the 18 shifts in those curves due to irradiation as well as the 19 shape changes.
20 The primary work will be done using a two-inch 21 thick specimen. It is called a CT specimen. In plan form, 22 it is a rectangular shape about 8-inches high -- no, I'm 23 sorry -- about 4-inches high and about five or six-inches 24 long, two-inches thick, just to give you a feel for the size 25 of the specimen.
() Heritage Reporting Corporation (202) 628-4888
4x-
, '100
-- 1 Irradiations for the bulk-_of the work will'be at 1 -
2 X 10-19. . We are also going to be doing some work 11ooking at 3 irradiation saturation using specimens thatLare-just half 4 :the size'of these,.this 1 TCT.
5 We will be looking at 5 X 10-18 and 5 X 10-19.-
6' We.are going to be looking at some rate effects on 7 this material. Because the B&W owners group-is using it in 8 their surveillance program, we have the opportunity now for
- 9. a good comparison between test reactor and power reactor.
10 So we are going to be looking some rate effects 11 work.
12 We may, we may end up going to much larger 13 specimens, depending on what we find in these two
() 14 irradiations.
15 We may be forced to go to larger specimens. That.
16 is a very costly thing to do and it uses up a lot of 17 material very quickly.
18 So we do not want to use it if we can avoid it.
19 I would like to turn, then, to the stress and-20 fracture analysis research. The research addresses both 21 reactor pressure vessel analyses as well as analyses of our 22 test vessels, the bench mark experiments.
23 Neil mentioned, I think, that the difference
'24 betwee'n -- he got to the margin of two, 1.1 times the design 25 pressure. Depending on what you do in the evaluation
() Heritage Reporting (202) 628-4888 Corporation
101
/
Q 1 criteria.
2 If you stay below about 4500 psi, we can get away 3 using a plastic zone-size correction to linemf elastic 4 fracture mechanics analysis.
5 This simplifies a lot of people's lives. It gives 6 us analysis methods that have a lot of history and that the 7 technical community is pretty comfortable with.
-8 If we adopt a criteria that forces us to go 9 significantly above that number, then we have to get off 10 into the full blown elastic-plastic analyses, elastic-11 plastic fracture mechanics analyses.
12 They are much more complicated. They are much 13 more costly to perform. And the technical community is not r- 14 quite as satisfied with some of that technology as they are Lg /
15 with the LEFM plastic zone size correction.
16 For the test vessels, however, we find that we 17 almost always have to go to these more elegant analyses.
18 We have recently spent a fair amount of money with 19 Oak Ridge reperforming some finite element analyses on a 20 particular test vessel called V8A.
21 We have made significant improvements in our 22 ability to predict something fairly simple - pressure 23 versus strain -- from the experiment.
24 We find that improvements in that analysis has led 25 us to much better comparisons between the fracture analyses i
(~ Heritage Reporting Corporation k (202) 628-4888 s
?
I 1
_ _o
102 1 and the' actual experimental results.
' l2 -
But again, that gets us into areas where we have
'3 to use'much more sophisticated analyses that may not be ,
4' warranted, depending on the evaluation criteria that are 5 ultimately adopted.
6 .Neil is going to tell you a little-bit.more,-when 7 he gets back up here, about. axial versus circumferential 8 cracks.
9 Let me simply say now that we have an analysis 10 effort that is just getting underway at Oak Ridge looking at 11 axial cracks that span the circumferential welds versus 12 circumferentially oriented cracks in the circumferential.
13 welds.
(- g 14 It seems like a straightforward thing to do, but
%/
15 it turns out it is requiring some fairly sophisticated 16 analyses and'it may'cause us to go back and rethink how we 17 developed the material property data.
18 That work is just now getting started.
19 The material properties research, this is -- Neil 20 mentioned controversy.
21 It is really in this area that the controversy 22 first started to surface. There was a fair amount of 23 discussion and a lot of argument on correlations that were 24' developed between Charpy data, material chemistry, the 25 fluents values and the JR curve.
O Heritage Reporting Corporation (202) 628-4888
.. A
103 o)
(, 1 Many people don't have JR curves available to them 2 or at least haven't had for a while now. And so they wanted 3 to use the surveillance data. We needed correlations 4 between'the surveillance data, the Charpy data, and the JR 5 curves.
6 We have work ongoing now that is making a 7 significant improvement in our ability to predict JR curves 8 based on Charpy specimens, given other inputs such as 9 chemistry and fluents.
10 The real controversy, however, came about in 11 trying to predict -- excuse me -- in trying to analyze these 12 JR curves.
13 The tost results which you actually measure is
/'"N 14 specimen, the applied load, the displacement at-the load
\d 15 line and the crack line.
16 That information then is converted to J versus the 17 change in crack line. We thought, up until two years ago, 18 that we had a modification to the accepted ASTM analysis 19 that was making a significant improvement in our ability to 20 predict or to evaluate J from the material properties 21 specimens.
22 We sent the people in Annapolis, the David Taylor 23 Research folks, we sent them off onto a program called JM 24 Validation, JM meaning the modified J.
25 They discovered that indeed the modification to J
() IIeritage Reporting Corporation (202) 628-4888
, 104
- p . _ . ..
' . 5 Ll' appeared to be causing artificially high slopes in our it curves.
- 3 Recall that the slope, when we do an instability.
f4 ' calculation, the sicpe is a key parameter.
5- So they called me one day and said you better come 6' talk.to us. That revelation. led to the controversy that 7 Neil-mentioned.
8 We have spent a fair amount.of money and have 9 involved people literally all over this country in trying to 10 sort out-what is the right way to analyze these-test 11 results.
12 We think we now have a pretty good handle on it, 13: although-at the subcommittee meeting, Professor-Hutchinson,
' 1'4 ' who was consulting for the subcommittee, offered some 15 suggestions for additional analysis work.
16 And we have asked the Oak Ridge people to take 17 those to heart and take a serious look at potential further 18' improvements in how to do this.
19 Today, we think we have a much better handle on 20 how to evaluate the laboratory test specimen data so that 21 the-materials data used in the analyses will reflect what 22 should go on in the pressure vessel.
23 The laboratory specimens, the specimens in the 24 surveillance capsules,-tend to be fairly small. So you get 25 small amounts of valid crack growth from those.
Heritage Reporting Corporation (202) 628-4888
> g D
L- 105
' k ); L1' To do-an' instability analysis for the reactor ,
2' pressure vessel requires large amounts of. crack growth.
3 .Neil,;again,.is going to come back to that issue.-
4 But we have had a fairly active' effort ongoing now-E 5 in. developing ways to extrapolate the small' specimen data to
- 6. large amounts of crack growth.
7 Finally, looking at the validation research, we
'8 need to. provide bench marks that can be used by the 9 analysts,'by the licensing staff, to satisfy themselves that 10 indeed the criteria are adequate.
11 We have intermediate test vessel 8A. That 12' external was performed several years ago. However,'it 13 continues to be "the" bench mark that has been used by'the
.g 14 ASME~ working group on flaw valuation and.in deciding on
( '
15 evaluation criteria.
16 Pressurized thermal shock is no less of a 17 consideration for low upper-shelf vessels than it is for any 18- other vessel.
19' Two or three years ago we performed Pressurized 20 Thermal Shock Experiment No. 2 which used a low' upper-shelf.
21 . material but the tensile properties were also low.
22 That has created some difficulties in evaluating 23 that result and convincing us that it provides a legitimate 24 bench mark analysis or experiment.
25 It has led us to plan Pressurized Thermal Shock Heritage O' Reporting (202) 628-4888 Corporation
A 106
() l' Experiment No. 4, which will use a low upper-shelf weld that 2~ will have the right tensile properties.
3' We also have a fair amount of work in'the wide 4 plate crack arrest. experiments to provide crack arrest K-1-A 5- for these materials.
6 DR. SHEWMON: You mean in that case weld material 7 was put"in at-the-tip of the crack in someLof the tests?
8 MR. MAYFIELD: No , sir.
-9 Those were all the low upper-shelf material that.
.10 was used in PT SE-2, so the tensile properties are wrong-11 there, also.
12 We have material that we are not_using in wide
-13 plate tests but in' smaller tests that have the right
-14 material properties and has a weld.
15 The right tensile strength is what I was trying to 16 get to.
17 I will try and summarize. We really do have a 18 multi-faceted research program. I am sure you hear this 19 from any Research Program-Manager that stands up and tells 20 you he has got a multi-faceted program, because that is what 21' you are supposed to say.
- 22. This one I can tell you legitimately it "is" a 23 multi-faceted program. We have a lot of different people 24 involved from a lot of different laboratories. I 25 So far they have been working fairly well together O Heritage Reporting Corporation (202) 628-4888 1
'li
');
107 -l
)
1 with:the-intent of.providing a good technical basis for 2': developing criteria.
3 -The rasearch is subjected to periodic peer review ]
4 within the ASME,-flaw evaluation working group, as well as 5 several different ASTM technical committees.
6 We do have a_ good cooperation and a fair amount of 7 coordination within the industry, in.particular EPRI and the 8- B&W owners group.
9 Currently it has been in evaluating the Midland 10 materials and incorporating those in our research program as 11 well as the B&W owners group surveillance program.
12 Are there any questions about the research 13 program?
. .14 (No response) 15 If not. Neil?
16 MR. RANDALL: Well, let's talk then about the 17 development of criteria.
18 As you have heard, this intersection of the curve 19 that defines instability, the flaw and ductal tearing, for a 20 quarter T flaw in the reactor vessel wall, occurs at Delta A 21 values normally around six-tenths of an inch.
22 And therefore, if the materials data you have come 23 from specimens where the ligament that could tear is either 24 a half-inch long or one-inch long, depending on the size, 25 and those are the typical sizes from surveillance, and if j
()
Heritage Reporting Corporation (202) 628-4888
108
(). I the valid amount of crack growth is three-tenths or less of 2 that ligament, you don't have curves out to there; you have 3 curves that stop for a half-T specimen at about .15-inches 4 crack level.
5 For a one-T specimen, at most, three-tenths, 6 because of the problems and uncertainties in extrapolation.
7 The first attack we made on the criteria that the 8 Code Committee had proposed was let's fall back from an 9 instability criteria to a crack initiation criterion.
10 And we defined crack initiation quite arbitrarily 11 as a tenth of an inch of crack growth. Not quite 12 arbitrarily, since we set it small enough so we would have 13 that measured value of J material even from the smallest 14 surveillance specimens.
15 There was another problem that we found when we 16 started to do sample problems with the Code's criteria. And 17 that was, for a plant that was still above 50 foot pounds, 18 everything is fine.
19 When it fell below 50 foot pounds and we did this 20 analysis, if we used lower bound J material properties, they 21 would not come close to meeting it. The analyatical 22 approach would say oh no, you don't need 50; you need 55 or 23 60.
24 Well, that doesn't prove that the analytical 15 approach is wrong, but it is disconcerting to have criteria
() Heritage Reporting Corporation (202) 628-4888
1 l
l l 109
('-l 1 that works that way.
2 So we set about to rethink the question of 3 criteria and we have proposed to the Code Committee some 4 alternatives, which I want to discuss.
5 DR. SHEWMON: "We" in this case is who?
6 MR. RANDALL: This is the NRC staff members of 7 this Section 11 Committee.
8 DR. SHEWMON: Okay.
9 MR. RANDALL: The official member is Chi Cheng.
10 I have gone in his place at times.
11 So it is between the two materials branches.
12 DR. SHEWMON: Okay.
13 MR. RANDALL: You have heard most of this sto ry.
() 14 So to summarize, the Code's criteria are quarter-T 15 flaw, and we are not going to charge that for purposes of 16 avoiding argument, we hope.
17 The amount of thermal stress that you add is 18 whatever the tech spec max cool down rate gets you. It may 19 not be a hundred, but very often it is a hundred degrees an 20 ounce.
21 Pressure, we have talked about, comes about -- you 22 need 5500 pounds. You need stability at that point in the 23 Code's criteria.
24 We are going to fall way back from that. I will 25 describe why in a moment.
(/~)T Heritage Reporting Corporation (202) 628-4038
m--
}
l l; 110
- 1. The Code does not talk too much about lower-bound
[]n 1
2 . properties or medium properties or whatever. It simply says 3 " characteristic of the material".
4 These new criteria, we put a lot of stress.on 1 5 trying to be sure that we have bounded the toughness of the.
6 material in the belt line.
7 And as I just said, we picked what amounts.to an 8 initiation criteria at a crack growth of a tenth of an' inch.
9 There is also a criterion on the slope ht that 10 Delta A which turns out, for the Linde 80 weld metal, it is 11 sort of a never-mind. At least in all the data we have, the 12 slope is plenty high to be stable there.
13 Well, the effect of doing this, if I may come back d 14 once more to this graph, is that J applied falls down from
' 15 there to there.
16 (Speaker points to graph) 17 Why did we pick 31 1/47 18 We wanted a criterion where we had covered 19 ourselves for the largest pressure we could expect in Level 20 A and B loading. We were willing to trust the safety valves 21 to limit it to 1.1 P design.
22 They might do a pre-service hydro, a repeat of 23 that, for life extension or after some large repair. So we 24 set it at the pre-service hydropressure, which is 31 1/4.
25 That means that our criterion is now this Heritage Reporting Corporation (202) 628-4888
111 Q
\~/ 1 question: does J material fall above J applied at a tenth.
^2 DR. SEEWMON:- Now, the margin for something like 3 that comes from the 3100 pounds pressure. So as long as 4 your.J material is above that, J applied by anything that 5 you consider still has the desired margin and passes, is 6 that right?
7 MR. RANDALL: Yes.
8 We know there is more margin before you get to 9 crack instability. The thing is,.we don't know how much 10 because we are not yet willing to extrapolate the curve out-11 to six-tenths of an inch of crack growth.
12 Well, we had John Nerkle do some sample problems-13 and here is a summary of the first thing he tried, which I 14
() put up to show you --
15 (Speaker presents graph) 16 -- what it means if we take lower-bound material 17 properties.
18 This is a correlation of J at a tenth of an inch 19 versus the Charpy upper-shelf energy, which is obtained for 20 us by a man named Heiser at MEA looking at all of the HSST 21 data that Mike described for you.
22 He fitted the JR curves with a power law and then 23 correlated those constants with Charpy upper-shelf. And 24 from that we were able -- you know, from his report you get 25 a curve of a mean value of J at a tenth and another curve
( Heritage Reporting Corporation (202) 628-4888
I i
112 P
't 1 which'is a 95/95-lower-bound, which.is very close to a two-2 sigma lower-bound toughness curve.
i 3 On the same graph, John Merkle gave us' values for i
4 J applied for-three different vessel wall thicknesses.
5 L These are three typical ones for PWRs.
6 And you can see, you can read the bottom half 7 there, that by this criterion we are proposing, it is'indeed
-8 borderline for the.8 5/8-inch vessel wall.
9 You need.about 45 foot-pounds for this class of
- 10 vessels and for the 6 1/2-inch ones, about 35 foot-pounds.
11 So the required shelf energy is really quite 12 sensitive to wall thickness.
13 DR. SHEWMON: Neil, would it be fair to say --
14 you say it is sensitive to wall thickness. If you had the 15 same thickness, same depth of flaw in each of those three 16 vessels, instead of having it a quarter-T and you just said 17 I will take it two-inches or something like that, would 18 there be any of that sensitivity or would it just be one 19 value for all three thicknesses?
20 MR. RANDALL: Well, there would be less 21 sensitivity but"it wouldn't go to zero because the wall 22 thickness also affects the thermal strengths from the cool-23 down, the thicker vessels having the higher thermal stress.
24 So that would still be there. The contribution of 25 the thermal, if it is for a 100 degree F an hour cool-down, O aerie 9e aegereies cerre (202) 628-4888 eiee
113 f'~)N
(_ 1 is roughly 20 per cent of the total.
2 (Pause) 3 No, it is 20 per cent of K, so it is roughly 40 4 per cent of the J value. So it would push these together, 5 but not all the way.
6 Okay.
7 Well, I will show you this to show you where we 8 are in doing sample problems and also to show you that the 9 thinner vessels probably have enough margin to get by for a 10 while.
11 Another class of vessels that have something in 12 their favor are those with the ring forging, so there are no 13 axial welds.
14 When we do pressure temperature limits on a vessel
()
15 that has only circumferential welds, we make them postulate 16 the flaw to be in the axial direction; the reason being, if 17 this weld matal is brittle, even though the crack tront is 18 only a fairly small fraction of the total, 2 pop in from 19 this brittle material might run into this material and in 20 the pressure temperature limit calculations we don't get 21 that sophisticated.
22 So we make them postulate this.
l 23 For ductal tearing, we do not have thic pop in 24 phenomenon to worry us. And we think we probably are 1
25 justified in saying no, you don't have to postulate this
() Heritage Reporting Corporation (202) 628-4888 l
l
114' D)
(~ 1 flaw when you do upper-sl s1f analyses.
'2 Well, you could do something sophisticated taking 3 into account both properties. That is what Mike referred 4 to. You know, that takes some analytical tricks.
5 Or, you could use this picture, postulate the flaw 6 to lie in the weld. And then of course pressure stresses 7 are only half of what they were in the hook direction, so J 8 applied will be less.
9 DR. .SHEWMON: Now these welds, there are two sets 10 of vessels: the Westinghouse. group which, for some reason, 11 happens to have the lower upper-shelf energies, and the B&W 12 groups.
13 MR. RANDALL: Yes.
() 14 15 DR. SHEWMON: The B&W vessels were made.with ring forgings but not all of the Westinghouse vessels?
16 MR. RANDALL: That's right.
17 DR. SHEWMON: But all the vessels were made for 18 B&W but made different kinds for Westinghouse plants than 19 for B&W plants?
20 MR. RANDALL: They began with plates.
21 Let's see, at least one B&W vessel has axial 22 welds. It is one of the Oconees. I am not sure whether it 23 is more than one or not.
24 The early vessels were made with plates and 25 Westinghouse got caught in that.
() Heritage Reporting Corporation (202) 628-4888
_ _- ___a
! 115
('N
(_) 1 DR. SHEWMON: Point Beach and Turkey Point?
2 MR. RANDALL: Not Turkey Point.
3 DR. SHEWMON: But Point Beach.
4 MR. RANDALL: Is pretty early, isn't it?
5 MR. RANDALL: I don't recall.
6 MR. ELLIOTT: This is Barry Elliott.
7 DR. SHEWMON: Yes, Barry Elliott can tell us.
8 MR. ELLIOTT: Point Beach II is circumferential 9 weld.
10 Point Beach I has longitudinal and 11 circumferentials.
12 Turkey Points have circumferentials.
13 And Ginna has circumferentials.
14 DR. SHEWMON: Arkansas I?
}
15 MR. ELLIOTT: Arkansas I has longitudinal and 16 circumferentials.
17 Rancho Seco has longitudinal and 18 circumferentials.
19 DR. SHEWMON: Probably don't have to worry about 20 Rancho Seco too much.
21 MR. ELLIOTT: Crystal River III has longitudinal 22 and circumferentials.
23 DR. SHEWMON: That's far enough.
24 Thank yo~u. So it is sort of a mixture?
25 MR. ELLIOTT: Yes. It depends on the size of the
( Heritage Reporting Corporation (202) 628-4888
k 116 b 1 vessel. A thinner vessel typically could make ring forgings 2 and a thicker ~ vessel is needed to use plates. So they had 3 to use~1ongitudinals.
4 DR. SHEWMON: Okay.
5 Have you finished that point?
6 MR. RANDALL: Yes.
7 That brings me to a summary slide.
8 Some generic considerations that give me a. warm
'9 feeling about continued operation: No. 1, from all our 10 analyses,'there-is. plenty of margin at normal operating 11 pressure, and there aren't many transients that lift.the '
12 safety valves, which are normally set at 2500 pounds..
13 So over pressures are not something that worry us 14 as far as accident scenarios go, like pressurized thermal
{~}
15 shock and low temperature over pressurization on start-up.
16 There is an accident condition we call ATWOS, 17 Anticipated Transient Without Scram.
18 It has been considered at length over the years.
19 It finally resulted in a rule, 10 CFR 50.62, that required ,
20 certain instrumentation and systems changes that reduced the 21 frequency I don t know how much; maybe a factor of ten at 22 most.
23 So overloads on the upper-shelf, in other words, 24 operating temperature or within a couple hundred degrees of 25 it, you know, are not something that happened very often.
Heritage Reporting Corporation (202) 628-4888
117
), 1 Finally, the vessels'that are susceptible to low 2' energy ductal tearing are restricted to a fairly few ones
'3 when you think they have to have lineated wells, axial 4 welds, a thick-weld belt-line and high fluents, meaning 5 later in life.
6 So this doesn't eliminate the problem, but it 7 reduces it to a fairly small number of vessels.
l l 8 MR. WARD: Let's see. What. pressure ~is predicted 9 in the ATWOS analyses?
10 MR. RANDALL: Well, there was a great range of 11 pressures over the years. I think the biggest number was 12 7000 pounds.
13 MR. WARD: Yes.
. 14 MR. RANDALL: There was a time when they tried.to 15 write a rule to reduce the pressure to make sure the 16 pressure did not exceed 3200. But that is not in the rule 17 now.
18 DR. SHEWMON: Now that is worse actually for 19 combustion. Westinghouse came out pretty good on that 20 because they tended to have more pressure relief capability 21 than the other plants.
22 MR. RANDALL: I'm afraid I don't know.
23 MR. WARD: I think that is true.
24 But there is still some pressure in er: cess of 25 2500, I guess, that you get in that transient. That is what
() Heritage Reporting Corporation (202) 628-4388
_ _---= _ _ _ _ _ _
'118 1 I was'asking, if anyone knew what that number was.
.2 DR.'SHEWMON:
~
- 31. Okay.
3: Yes, I don't know.
4' DR. KERR: Well,.as I remember calculations, 5 :which are probably done somewhat conservatively for 6 Westinghouse, give not more than about 3200 psi.
7 DR. SHEWMON: Any other questions?
8 (No response) 9 Thank you, Neil.
10' MR. RANDALL: Barry Elliott then will talk about 11 some of the plant-specific work.
lL2 DR. REMICK: Is this the point then where we need 13 to close the meeting?
14 MR. RANDALL: No.
15 I think we will close it about two-thirds of the 16= way through the talk, when he gets into particular owner
.17 groups.
18 DR. REMICK: All right.
-19 MR. ELLIOTT: There are two sets of hand-outs.
-20 The people at the table will have the part with the 21 proprietary-slide in it and the other people in che room 22 will have the same slides or viewgraphs, except for that 23 one.
24- DR. REMICK: All right.
25-Heritage Reporting Corporation (202) 628-4888
119 (f }j m 1 MR. ELLIOTT: My name is Barry Elliott.
2 The requirements on low upper-shelf energy are in 3 Appendix G of CFR 50 and they say that reactor vessel 4 materials must have Charpy upper-shelf energy greater than 5- 50 pounds unless it is demonstrated or the matter approved 6 by the Director of NRR.
7 The lower values of upper-shelf energy will 8 provide margins of safety against fracture equivalence as 9 those required by Appendix G of the ASME code.
10 When the Charpy upper-shelf energy is less than 50 11 foot pounds the licensee must perform '.00 percent volumetric 12 examination, provide irradiated supplementary fracture 13 toughness data and provide an analysis to demonstrate S 14 margins of safety.
(G i
15 In addition, test methods for supplementary 16 fracture toughness tests must be submitted to and approved 17 by the Director of the Office of Nuclear Reactor Regulation.
18 To implement these requirements we have taken the 19 following action. In a September 24, 1987 memo to Dr. i 1
20 Murley from Starastey we identified the five plants which 21 were critical in this issue. They were the five plants at j
)
22 that time thrt looked to be below 50 foot pounds. !
I 23 The estimate was based upon the Reg Guide 1.99 )
i 24 Rev. 1 calculation method of predicting upper-shelf energy. I 25 The five plants identified with Turkey Point 3 and 4, Point I
( Heritage Reporting Corporation (202) 628-4888 l
120 es i \
(_/ - 1 Beach 1 and 2 and Ganay.
2 We have provided in the industry NUREG-0744 with a 3 method for evaluating upper-shelf energy. As far as 4 volumetric examination is concerned we have issued a 5 regulatory guide 1.150. Testing of reactor vessel walls are 6 in pre-service, in-service examination. This is to 7 supplement the code requirements, provide bett.s care for 8 the key variables in inspection, 9 DR. LEWIS: I wonder if -- I'm a dumb physicist so 10 let me ask a dumb question -- how are reproducible are these 11 measurements? If I were to put two different engineers in 12 closed laboratories with samples from the same lot of 13 material to measure the upper-shelf energy, how close would f')
ss 14 they be? Or if I were to put Shewmon into a room on two 15 separate days with two separates samples from the same lot, 16 how could close would the measurements be to each other?
17 Just getting some idea.
18 MR. ELLIOTT: I think they would be very close 19 because the test itself is calibrated to a very -- is 20 calibrated to an MBS standard which is very closely 21 controlled. You've got to keep doing that calibration to 22 control your test.
23 It's a very simple test.
24 DR. LEWIS: No, I understand that.
25 MR. ELLIOTT: I think the test would be very -- if
/
(_j Heritage Reporting Corporation (202) 628-4888 l
l
121
- 1. 'l-' you ran into the standard.and~you took the care'you would 2 como out with very close answers.
3- DR. LEWIS: Well,.very close doesn't help,me.
4 What does very close mean?
5 MR. ELLIOTT: Within a football.
6 DR. LEWIS: Within-a football, two percent. I'm 7 impressed.
8 MR. ELLIOTT: Very close, something like that.
'9 DR.-LEWIS: I didn't know anything could be 10 measured to two percent.
'11 DR. SHEWMON: Maybe four percent. I think if you 12 would have asked him'on that last question -- there has been 13 some' NRC work funded in which they did indeed get: Shewmon or
(} 14 engineers but people trained and certified to do UT 15 examinations and they don't always come up with the same 16 'results with a higher frequency than one might like.
17 So there has been changes of the sort that he has 18 talked about there which decrease that uncertainty, but by 19 how much is not as clear.
20 One comforting thing is that you're talking about 21 rather large flaws that specified or postulated in this 22 analysis, and not finding those is indeed -- would be 23 extremely uncommon.
24 DR. REMICK: I would like to note for the record 25 that we have never hesitated to allow a physicist to ask
() Heritage Reporting (202) 628-4888 Corporation
.122
[ 11 dumb questions in the past.
< 2 DR. LEWIS: That's simply because that's all 3- poople:can understand around the table..
-4 (Laughter) 5 -DR. SHEWMON: Go ahead, sir.
6 -DR. LEWIS: You asked for it.
7 DR. REMICK: I did.
8 MR. ELLIOTT: To get the upper-shelf energy 9 ' requires more than one test. -It requires several tests-at 10 different: temperatures. The actual test varies, but the 11 upper-shelf energy -- because we're taking several_ tests at-12 'different temperatures, $f course, the' upper-shelf should be 13 very;close.
()'14 The actual energy for a given test could varyam 15 . lot, 15 percent or so. But when you average out a whole 16 : bunch of tests,.they should come pretty close.
17 DR. SHEWMON: Now he's going to ask you the
-18 standard deviation.
19 Let's go on. We'll supply him with numbers on 20 that.
21 DR. LEWIS: And you'll educate me.
22 Paul, you see why I'm asking.
23 DR. SHEWMON: I'm glad he added :lus last part, 24 because there certainly is scatter from sample to sample and 25_ with temperature.
( Heritage Reporting Corporation (202) 628-4888
123 p
(_/ 1 MR. ELLIOTT: The initial analysis of fracture 2 toughness for this problem was to use HHST data. The HHST 3 data has a different flux rate than commercial reactors, so 4 I was a little bit concerned about using that for safety 5 analysis.
6 I think it's more reliable to rely on commercial 7 reactor data where the flux is much similar to the reactor 8 than the HHST data. -
9 We are meeting with the B&W Owners Group which is 10 really the people with the data and which who are generating 11 the data and we will be using that data to solve most of 12 this problem.
13 The test method was reviewed by the Staff and 14 approved. We have an analysis in-house that uses HHST data-
{}
15 and indicates that plants meet the safety margins for 40 16 effective full power years. Staff agrees with the 17 conclusion but requests additional information.
18 DR. SHEWMON: Now, what is this test method review 19 and approval's 20 MR. ELLIOTT: The test method would be the -- the 21 material test method to get the JR curve.
22 DR. SHEWMON: Well, if everybody agrees on all 23 these good things, why is it that NRR hasn't been able to 24 tell people what their criteria are yet or what is it you 25 haven't been able to do?
() Heritage Reporting Corporation (202) 628-4888 c_____-. _ _ _
(
124
() 1 MR. ELLIOTT: There are two problems that we have 2 in trying to solve. First is whether to use J modified or J 3 deformation.
4 When NUREG-0744 came out it recommended using J 5 modified. J modified gives much higher values of low 6 carrying capability than the J deformation.
7 The second problem is not how to do the test, but 8 how to evaluate the data from the test and how valid is the ,
9 data from the test.
10 The current criteria validation only allows one-11 tenth of an inch -- one-tenth of the remaining ligament, as 12 far as crack extension. And on a very small specimen like a 13 half-T, it comes out to be very small crack extensions in
(~g 14 the .1.
%/
15 The problem is to get the solution to the problem 16 at 5,000 psi or above, requires six-tens of an inch crack 17 extension which is beyond the validity zone for the type of i 18 specimens that are in the surveillance program.
19 For the critical plants which we have identified, I 20 this what the plants have done to meet our regulations and 21 to assure vessel integrity. It also gives you the neutron 22 fluent at the quarter-T on the beginning of this year for 23 the critical weld in each vessel.
24 Four of the plants have flux reduction programs of 25 half neutron absorbers. One has a low leak. All plants
() Heritage Reporting Corporation (202) 628-4888
125
( )~ l' 'have implemented Reg Guide 1.150 in their in-service 2 inspection program.
3 DR. SHEWMON: How many of them have run - you say 4 they have implemented it, but since these things come only 5 10 years they can implement it and it still might not change '
6 anything for nine years.
7 MR. ELLIOTT: The last inspections which are 8- identified here were all run using the Reg Guide 1.150 9 methodology.
10 DR. SHEWMON: So it was issued in '83, but Turkey 11 Point used it in '81.
12 MR. ELLIOTT: Right. They use a draft version 13 which is not much different. They knew what was going on.
fg 14 MR. CARROLL: What's the explanation of large d 15 ' fluent difference between Point Beach 1 and 27 16 MR. ELLIOTT: The critical weld for Point Beach-2 17 is circumferential weld. The critical weld for Point Beach-18 1 is a longitudinal. It just so happens the longitudinal as 19 lower. !
20 DR. SHEWMON: Now, the half-N absorbers, are they 21 all because of the PTS or because of wanting to cope with 22 low upper-shelf?
1 23 MR. ELLIOTT: I th they're there for the FTS.
24 And also, I would say these plants are looking into license 4
25 extension. Turkey Point has a long way to go before they Heritage Reporting Corporation (202) 628-4888 i
b' 126' 1 meet'-- they have a. problem with PTS.- Point Beach has a 2 problem with PTS.
3 I think mostly all these plants'are looking for 4 longer life way beyond their present license.
5 DR. SHEWMON: Okay.
6 MR. ELLIOTTi And fracture mechanics. analysis was 7 submitted for, Turkey: Point to NUREG-0744. They're going to 8 supplement this analysis with the B&W Owners Group and data 9 from-the program. And all plants are now finally part of 10 the. Owners Group:and will use the Owners Group methodology-11 and data to sh'ow the margins of safety for their plant.
'12 MR. WARD: Barry, did you say that Point Beach-2 13 had the ring sections?
MR. ELLIOTT: Point Beach-2 has -- let me-( f 14 Yes.
15' just' check to make sure. Point Beach-2 has circumferential.
16 And for Point Beach-1 they have a_ longitudinal. They have a 17 circumferential,-too, but it has lower stresses because -- I 18- mean,.it's. orientation so the longitudinal-would probably be 19 limiting and that's the flux for the fluent for the 20 longitudinal.
21 MR .' WARD: I guess I'm looking at something the 22 wrong way. I mean, it looks like -- does the longitude --
23 MR. ELLIOTT: Do I have them backwards?
24 MR. WARD: Well, you got a higher flux in Point 25 Beach-2 because the weld is in the wrong place.
() Heritage Reporting Corporation (202) 628-4888
127-1 .' . DR. L SHEWMON: .- Well, the weld.is every place, all e 2- the way around.
3 MR. ELLIOTT: Yes. Point Beach-2 has 4 circumferential. The peak flux location turns out to be on 5 a location within the circumferential weld.
6 MR. WARD: Yes.
.7 MR. ELLIOTT: A longitudinal weld has been 8' oriented in Point Beach-1 so that it's away from the peak 9 flux location, so it gets less fluent.
10 MR. WARD: But its circumferential welds are moved.
11 out of the highest flux region then, too, I guess. Okay.
12' That's kind of surprising.
13 DR. SHEWMON: The circumference that they take the 14 middle core --
O 15 MR. ELLIOTT: The middle core will always get the 16 peak flux. The longitudinal welds don't because they're out 17 of the peak flux location.
18 DR. SHEWMON: How high is the plate in this ring 19 -- six feet?
20 MR. ELLIOTT: The actual core is 12 feet.
21 DR. SHEWMON: I know, but that wasn't my question.
22 MR. ELLIOTT: So I would say the actual weld is a 23 couple of inches only.
24 DR. SHEWMON: How high is that ring? You said 25' there is a ring portion here with only a circumferential O Heritage Reporting Corporation (202) 628-4888 l
p 128
. e.
1 . weld,.is'that ring six feet high?
2 The middle ring around the pressure vessel?
3 MR. ELLIOTT: This is not for the' ring; this is 4~ for the weld.
5 DR. SHEWMON: I know.
6 MR. ELLIOTT: The ring itself is probably four l
l 7 feet.
8 DR. SHEWMON: So that gets at only two feet above 9 core mid-plane if they center that four feet.
10' MR. RANDALL: There is a circumferential weld more 11 or less in the center of the core, in either case, ring 12 forging-or plates. In the case where the axial weld governs
'13 the circumferential doesn't govern because of chemistry presumably, copper and nickel.
(}L14 15 MR. MARD: Oh, because of the chemistry, okay.
16 MR. RANDALL: Right. Copper and nickel content..
17 DR. SHEWMON: Thank you.
18- MR. ELLIOTT: This is the non proprietary slide.
19 I'm just going to talk about the proprietary. data,
~20 I'm going to keep it at this part of as non-proprietary as I 21 can.
22 On the Turkey Point fracture mechanics analysis it 23 was done using the methods in NUREG-0744. It extrapolated 24 HHST data. It evaluated Level A and B service conditions.
25 The size of the floor evaluated was a quarter-T floor in Heritage Reporting Corporation (202) 628-4888
129 1 which its length'is six times it depth.
2 The pressure evaluated was 5,000 psi. And the cool 3 down rate was.100 degrees Fahrenheit per hour which was the 4 limiting condition for Turkey Point tech specs.
5 The analysis found that the material at 6 instability exceeded the applied value during these 7 operating' characteristics for 40 effective full-power years 8- at a fluent of 1.73 times 10 to the 19 neutrons per 9 centimeter square at the quarter-T location.
10 And, in fact, the J material which was at the time 11 J modified was more than twice J applied calculated.
12- Now the next slide is proprietary.
And I would 13 like everybody who is not part of the NRC to please leave 14 the room-right_now.
{}
15 (Whereupon, a closed session was held.)
16 17 18 19 20 21 22 23 24
'25
() Heritage Reporting Corporation (202) 628-4888 l
130 (v,) 1 DR. REMICK: Let's proceed.
2 MR. ELLIOTT: This is my summary. Licensees 3 programs, both the in-service inspection program, analysis, 4 and data acquisition to satisfy regulatory requirements and 5 will ensure the integrity of the reactor vessels.
6 Fracture mechanics analysis indicates there is 7 substantial margins during normal operation and anticipated 8 operational occurrences for all operating plants.
9 And then finally, cor tercial surveillance data 10 will be used to evaluate margins and end of license 11 conditions.
12 That's my last slide.
13 DR. SHEWMON: By commercial surveillance data you es 14 mean that it was obtained in commercial reactors and thus at d 15 more typical flux rates than commercial reactors or 16 whatever.
17 MR. ELLIOTT: Yes, More simulated in the flux 18 rate of an actual reactor. It will be irradiated in the B&W 19 -- one of the B&W plants.
20 DR. SHEWMON: I wasn't sure whether it was who 21 paid for it that might influence the data or the flux rate;
< 22 and the flux rate I could believe.
23 Any other questions?
24 (No response) 25 DR. SHEWMON: Thank you.
[')
Heritage Reporting (202) 628-4888 Corporation l
_______________O
131
.A.
P j 1 MR. CARROLL: I guess I had a comment more than a
. 2 question. In my some 30 years around this silly business we.
3 seem to have taken forever to come to closure on this 4 problem. Do you think we're near there than we have been in 5 recent past? There always seems to be some new issue that 6 comes along.
7 MR. ELLIOTT: I think we're very near. I think 8 the -- the trade-off here, we had to decide whether we 9 should decrease the margins or get better data. And we i
10 decided -- we're deciding on getting better data to get 11- realistically where we are.
12 All the criteria in the past did not take into 13 account what reality was. What the real material -- what we 14 can develop.
15 Now we're going around and we finally got on the 16 right track where we're going to get good material test data 17 which can support the license. And that's why I think we're 18 going to resolve this issue pretty soon.
19 MR. CARROLL: I'm encouraged.
20 DR. SHEWMON: As you may know, earlier in the 21 month I had a letter that was on the bulletin bcand that I 22 would suggest, I think in view of what I have learned since 23 then I would not recommend that we write a letter, although 24 the committee can do what it wants to later.
25 I think the program is proceeding, if not with
() Heritage Reporting Corporation (202) 628-4888
_ - i
132
() l' great haste at least proceeding.
- 2 That's all I have.
3 DR. REMICK: Is that it?
4 DR. SHEWMON: Yes.
5 DR. REMICK: Okay.
6 Gentlemen, the next agenda item requires staff to 7 be here who aren't here.
8 MR. MICHELSON: I'm looking for them. They were 9 here.
10 DR. REMICK: Oh, they were, okay.
11 We have a break scheduled anyhow at 2:45, so I 12 suggest we take the break now and return at 2:50.
13 (Whereupon, at 2:45 p.m. a break was taken.)
rg 14 DR. REMICK: All right, gentlemen, our next topic i V
15 is a fire risk scoping study. Carl Michelson is our 16 subcommittee chairman.
17 Carl, I turn the meeting over to you.
18 MR. MICHELSON: Thank you, Mr. Chairman.
19 The axillary and secondary system subcommittee met 20 on Wednesday of this week to discuss a recently issued 21 policy paper, SECY-89-170. It was issued on June 7, 1989.
22 This policy paper concerns the fire risk scoping 23 study which was conducted by Sandia Laboratory and which the
- 24. full committee heard about several months ago in a 25 presentation by Sandia and the Staff.
() Heritage Reporting (202) 628-4888 Corporation
133 A
..g 1 'The subcommittee members.in attendance were:
2 Catton; Kerr; Siess; Ward; Wylie. You didn't end up there.
3 Catton; Kerr; Siess; Wylie.-- Hal, were you there?
4 That's it. 'I thought we had more than that. And 5 myself.
6 We heard about Sandia's study a few months ago,' as 7 I said, and we proposed today to consider the 8 . recommendations that are in the policy paper that relate to
.9 this study.
10 We also would like to consider a proposed letter 11 which will'be on the table after the presentation. It's on 12 the table now then, good. In fact, it's a mustard yellow 13 color.
14 In Tab 6 of your book you will find on page 11 a 15 copy of the policy issue paper itself, so you can refer to 16 it.
17 The policy paper essentially states that there 18' will be no fire research work or there is none in progress 19 and none is presently planned for the future. However, in 20 the paper the Office of Research pointed out the possibility 21 that perhaps after the peer review of NUREG-1150 they might 22 ' reconsider this.
23 NRR has indicated that they have no needs, user 24 needs for future fire research work.
25 The subcommittee heard from Research concerning Reporting Corporation
()~ Heritage (202) 628-4888 I
._______ ____-______ -Q
l a
134 yx 1
(_) 1 this Sandia work.. -Since the-full' committee has heard this- )
2 before we decided only to have NRR come today to tell us in 3 .particular about the~ plans for the IPEEE program. This is -
4 -the individual plant examination for external events ,
5 program.
6- This program will consider certain. issues that are 7 discussed in the policy issue paper. And the subcommittee 8 is recommending that some kind of letter be issued.since the 9 Commission already has in' front of it the SECY document-on 10 the scoping studies, so we think our thoughts need to be 11 injected into the process.
12 So'after the NRR presentation then we will have a 13 first reading of the letter, and I assume at that point we 14 no longer use the record.
15 DR. REMECK: That's right.
16 MR. MICHELSON: I guess it's for the rest of the 17 day then.
- 18. DR. REMICK: Once we're at that point, yes, 19- MR. MICHELSON: I think it's the rest of the day.
20 So with those introductory remarks I would like to 21 introduce Mr. McCracken who will speak to NRR's plans and 22 program regarding this matter.
23 MR. MCCRACKEN: I'm Conrad McCracken, I am 24 currently Chief of the Plant Systems Branch at NRR. I took 25 that over two weeks ago. Prior to that I had Chemical
-() Heritage Reporting Corporation (202) 628-4888 i
I -
135
'() 1 Engineering Branch and Fire Protection was with me in 2 Chemical Engineering. And one of the provisos of going 3 where I did is, it stays with me in Plant Systems.
4 I am speaking here primarily as Chairman of the 5 Subcommittee on Fire, which is part of the External Event 6 Steering Group.
7 I think we need to go into a little bit of 8 background before we hit the decisions and where we're 9 going. And the background is the subject near and dear to 10 all of us which is Appendix R that we have heard about for a 11 long time.
12 The status and compliance with the regulations, 13 the Appendix R inspections have been conducted at all 14 applicable plants. The majority of those plants did meet
(-)3 15 the regulations with a number of exemptions or deviations as 16 they were reviewed. With the exception of a few plants that 17 we , in fact, did find were inadequate, they had not properly 18 implemented Appendix R. They are back redoing and we are 19 going through a complete reinspection of those plants.
20 Those we anticipate will be finished early next year.
21 The pre-operational plants that did not come under 22 Appendix R had inspections conducted or similar what we 23 would do for Appendix R, and they were required to comply 24 prior to startup. So we ensure prior to startup they met 25 the regulations.
Heritage Reporting Corporation
[~)#
'- (202) 628-4888
136
) 1- .DR. SHENMON: Can you tell me what "all applicable 2 plants" is?- I sort of get the impression this was a 3 backfit.
4 MR. MCCRACKEN: It was a backfit for all plants 5 prior to 1979.
6 DR. SHENMON: Thank you. l 7 MR. MCCRACKEN: As part of-completing the-8; implementation of the regulations on all plants, we now have 9' a tri-annual-audit inspection program where we go on a tri-10 annual basis to all the plants and go back and basically ,
11 reinspect to see what they-have changed since we approved i 12 their program. It's a review to see what has changed and 13 then a partici audit of things to make sure we didn't miss 1
14 anything in the beginning.
k -l 15 The summary is: all plants currently meet the ]
16 regulations or will do so shortly. If plants are found not -j l !
l 17 to meet the regulations, we will force them to comply. I 18 The area we are in the IPEEE, individual plant ,
k 19 examination for external events is, we're beyond the j 20 regulations. We are nov trying to see in the severe 21 accident statement, we are expected to perform a limited 22 scope analysis to discover particular vulnerabilities. And 23 that's the focus of the ienues I will be talking about the 24 rest of the day and where we' re going is the methodology and 25 how we intend to discover those vulnerabilities.
Heritage Reporting Corporation (202) 628-4888 )
i l
1 >
1 l . _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ . _
_ i
t 137 O
\_) 'l- The Externa 1' Events Steering Group was formed to 2- . provide direction on implementation of the policy. They 3 report to.the Director of Research. And the subcommittee 4 which I chair'on external events for fire reports to the
-5 Steering Committee.
6 Any plant-specific vulnerabilities.that are 7 identified through this process within the guidelines of the 8 policy statement will be addressed through the backfit 9 process. So anything we find out wrong, the way we ensure 10 implementation is backfit process, and that's the way it 11 will have to go through the cost benefit analysis.
12 MR. MICHELSON: Could you clarify for me something 13 that puzzles me from time to time, and that is the severe
() 14 accident policy, I used to think, deatt'with accidents 15 beyond-the design basis of the plant. And fire, of course, 16 was kind of, I thought, a design basis for the plant, but~a 17 certain size' fire at least was.
18 Why are we mixing up, in other words, severe 19 accident with fire unless we're looking at fires beyond the 20 original design basis fires or something, which I don't 21 think we necessarily are, although we might be wanting to 22 include that.
23 MR. MCCRACKEN: We did not initially establish a 24 deszgn basis fire. There was a lot of discussion about 25 that. And there was a lot of interest in trying to I) Heritage Reporting Corporation (202) 628-4888
a )
T 138
() 1 establish a design basis fire, but we could get absolutely-2 no agreement on what it would be.
3 As a consequence, fire-not being a design' basis J i 4' the reason that this is being' addressed and the external
}
5- events-are beyond design basis is we're saying, the' design 6 basis includes the regulations, Appendix R and_SRP 951.
7 What we're doing now is going beyond those. We're.
8- looking for vulnerabilities that are not addressediwithin 9 the regulations which we consider part of the design basis.
10 MR. MICHELSON: So that's why we're calling it 11 severe' accident.
12 MR. MCCRACKEN: Right. That's why it falls into 13 -that category.
14 MR. MICHELSON: But we're not necessarily talking 15 about bigger fires than we might have envisioned for 16' Appendix R.
17 MR. MCCRACKEN: I don't think we envisioned them-18 any larger now than we did then.
19 MR. MICHELSON: Thank you.
20 MR. MCCRACKEN: The findings of the fire
.21 subcommittee which includes representatives from the various 22 officas within NRC. Each operating reactor should be 23 evaluated to determine plant-specific vulnerabilities to 24 internal fires. That was one of our two primary charters 25 was, do we need to conduct an examination or was Appendix R Heritage Reporting Corporation O- (202) 628-4888*
s 139
- 1 and the other regulations enough.
- 2. The committee concluded, the other regulations 3 were not enough and we did have to do additional 4 examinations. The reason we concluded that is that industry 5 performed PRAs and there are approximately 20 of those out 6 there now, demonstrate that fire can be a significant 7 contributor to core melt.
8 And some vulnerabilities that were identified 9 through these industry performed PRAs were, in fact, 10 corrected as they went through the PRA prior to recording 11 their results. So the results they reported in their PRAs 12 would show fire to be a significant contributor or actually 13 representative of an optimistic point of view because some 14 things that had been found were corrected before they
()
15 recorded resu s.
16 DR. SHEWMON* I have never seen one of these 21 17 PRAs. I don't kr.ow that I have looked hard for it, but I'm 18 sure I would have read it if it had crossed my desk. I 19 Because I've heard Carl talking about this, wondered when 20 somsbody was going to do a PRA to see how the two compared.
21 If I wanted to see one, are these proprietary 22 documents? Have they come out as NUREGs or where are they?
23 MR. MCCRACKEN: Some are proprietary, but there's 24 certain some available that I'm sure John Chen probably has 25 copies of them over in Research. He would be glad to send
) Heritage Reporting Corporation (202) 628-4888
140.
() l' some of the ones we've already got over.
2 .DR. SHEWMON: Okay.
3' MR. MCCRACKEN: I think the Brunswick one was the 11 latest one.
5 That's not the proprietary, is it, John?
6 MR. CHEN: Brunswick is, but NUREG-1150 has two 7 -- it's in the NUREG document. We can certainly send you.
8 DR. SHEWMON: Thank you.
9 MR. MCCRACKEN: The other factor that influenced 10 our decision that we need to search for vulnerabilities were 11 the results from the fire risk scoping study which indicate 12 the potential for plant-specific vulnerabilities in a number 13 of areas -- and I will go into that a little later on and 14 how we intend to address them. And that's also part of the
~15 policy statement that went to the Commission that was 16 discussed at the beginning of the meeting.
17 The other charter of the fire subcommittee was to 18 describe or identify a methodology that could be used to 19 search for vulnerabilities.
20 The fire subcommittee concluded that a level 1 PRA 21 is an acceptable methodology to perform the evaluation for 22 fire vulnerabilities. And also, that other methodologies 23 may be acceptable, but would require further development.
24 And a little on I will go into the fact that we are doing 25 additional development. There's an effort where industry is
() Heritage Raporting Corporation (202) 628-4888
<r 141 L1' - doing the primary. work and we're reviewing what they're
. 2 doing.
3 MR. WARD: Why do you think a' level -- why did'you 4 include a-level 1 PRA as acceptable?
5 MR. MCCRACKEN: We concluded a level 1 PRA was 6 acceptable because we had reviewed about 12 to 14 of the 7 PRAs that had been done. We saw the issues identified by 8 them, the vulnerabilities that were found and corrected and 9 concluded that that was a good methodology to identify 10 vulnerabilities.
11 It was doing a pretty good job of findings things 12- that we woulo not have found by any other methodology.
13 MR. WARD: I guess more - you haven't found that,-
14 for example, fire is a threat to containment capabilities?
15 MR. MCCRACKEN: No. The PRAs that have been done 16 have not shown a particular threat to containment, but they 17 do show a significant threat to core melt. And the policy 18 statement says you address:woth core melt and containment.
19 MR. WARD: But you have looked at enough PRAs that 20 have gone the level 2 or 3 to conclude that containment 21 isn't particular effective, is that right?
22 MR. MCCRACKEN: We haven't seen any obvious 23 indications at any of the ones we've looked at where we get 24 to an early containment failure scenario from a fire.
25 MR. MICHELSON: Did you look at any that were in
() Heritage Reporting (202) 628-4888 Corporation
w 142 f
'11 .the initiating event was'some. kind of involvement inside a h
2 ' containment like a LOCA and followed by a fire? Has there l 3 ever been any connection between those two?
6 MR. MICHELSON: Well, it depends on, for instance, 7 an interfacing LOCA which is a real LOCA and also involves 8 an outside of containment, and if it caused faulting of 9 electrical equipment that might reflect back and cause a 10 fire somewhere; and then the two would be coupled.
11 MR. MCCRACKEN: The one we normally get to is, 12 you get to a loss of reactor coolant pump seal cooling which 13 gives you the LOCA through the seals. That's one that fire 14 typically can cause.
15 MR. MICHELSON: But that's inside a containment.
16 MR. MCCRACKEN: Yes.
17 MR. MICHELSON: And that's a little easier to 18 address.
19 So it isn't obvious out-of-hand, I guess, that one 20 doesn't have to loo'. at the containment. It's just that you 21 haven't seen enough.
22 MR. MCCRACKEN: No, we haven't seen based on the 23 ones that have been done that that's going to be a 24 significant or dominate scenario. .
25 DR. CATTCN: Were people like yourself involved in
() Heritage Reporting Corporation (207) 628-4888
.i.
I' 143 i
) .
1 these --_ people,who know about fires?
2= -MR. MCCRACKEN; Oh, yes. Definitely people who 3 know about fires are involved in reviewing these and 4 . auditing them. There were people at the utilities who know
-5 about fires involved in putting in the input to them.
6 DR. CATTON: What about penetrations, wouldn't.the 7 fire-impact on penetrations?
8 MR. MCCRACKEN: The penetration seals?
9 The penetration seals are designed for --
10 DR. CATTON: Survive fire?
11 MR. MCCRACKEN: Yes.
12 DR. CATTON: He said, penetration seals are 13 designed to survive fire.
,r" 14 MR. MCCRACKEN: 'All the ones that are in fire 15 barriers, yes.
16 DR. SIESS: Oh, we're talking about penetration 17 seals.
18 MR. MCCRACKEN: Well, we have recently a topical 19 report, that type of seal going through concrete that 20 thick --
21 DR. SIESS: Or steel.
22 MR. MCCRACKEN: Concrete or steel is probably 23 something that you wouldn't even need to seal. When you get 24 a long narrow gap you can go with a fairly open penetration 25 seal and you really don't get fire or significant heat Heritage Reporting Corporation (202) 628-4888
_ _ _ _ _ . , _ _ _ . _ _ _ _ -__-_-_,___--___-A
2-144~
1 through it'.
2 DR. SIESS: I'm not worried about fire going 3 through it, I'm worried about radioactive material, going
'4 through it after the fire' burns it out.
5 DR. SHEWMON: But you've got to get it hot enough 6- to burn and unless it's a pretty flammable material'he is-7 saying there is.a' lot of heat sink on either side of it and 8 it's a narrow, long penetration.
9 DR. SIESS: Well, that's what some of the severe
.10 accident qualification tests have shown. That the outside 11 seal, even if it's a material that can't stand high 12 temperature it doesn't really see high temperatures.
13 MR. MCCRACKEN: Right.
14 DR. SIESS: But I don't know of any thnt had been-15 qualified for flames.
16 MR. MICHELSON: I think some of the old ones are 17 at epoxy, aren't they, or are they all glass now. I think a 18 lot of them epoxy --
19 DR. SIESS: There are a lot of old ones out there.
20 MR."MCCRACKEN: Yes.
21 MR. MICHELSON: I never heard that epoxy ones were 22 ever tested for fire.
23 MR. MCCRACKEN: Part of what they do for the 24 current fire barrier seal penetration test, some of thoae 25 epoxy. And some of the epoxy like a nine inch of epoxy is Heritage Reporting Corporation (202) 628-4888
n 145 1- about what you have in a three-hour barrier.
A:t .
\; 2 MR. MICHELSON: I think'you're looking-at them D 3 from'the viewpoint of propagation of fire and not from the
.4- viewpoint of remaining leak tight from the' containment side.
5 I just didn't know'that they had tested --
6' MR. MCcRACKEN: From the Fire Subcommittee I have' 7 to admit, I-haven't considered --
8 MR. WYLIE: Well, I don't know that.they have been 9 tested against the fire, but I would.be surprised if they 10 wouldn't pass because they're double wall to begin with and 11 they're filled inert gas. I just can't conceive of those 12 things.
13 HR.~MICHELSON: 'Just the heat would be what would 14
() affect. I wouldn't put them high --
-15 DR. CATTON: Gas isn't. going to stay there.
-16 MR. WYLIE: First of all, it's mounted into a heat 17 sink that's going to take the heat away.
18 DR. SIESS: The test on penetration seals in 19 -connection with containment, severe accident containment 20 ' operating at several hundred degrees accident temperature 21 for much longer periods than the fire could last, show that 22 although the -- and this was mainly for the BWRs where we 23 were worried about it, the MARC-I, they showed that the 24 outer seal hardly saw a temperature rise compared to the 25 inner seal. The inner seal saw several hundred degrees; the
( Heritage Reporting Corporation (202) 628-4888
1 g 146 i
( -l' ' outer seal didn't'getLvery much above ambient. And they 2 don't seem to be a weak spot.
'3 MR. MICHELSON: Proceed.
4 DR. REMICK: Do we have a comment from the Staff 5~ over here? Did you have a comment?
6 MF. CHEN: Add a few things.
7 DR. REMICK: Please identify yourself.
8 MR. CHEN: John Chen.
9 In our guidance we'll provide it. It's not just-10 -- I think level 1 is what is acceptable, but we also would 11 like them'to just identify what the. potential you have 12 containment bypass. Those sequence, we want them to 13 identify. But not necessarily go into the detail to analyze 14 it.
t 15 MR. MCCRACKEN: As part of our decision that a 16 level 1 PRA is acceptable, we are_ understanding -- accepting; 17 the fact that limitations do exist in the application of 18 fire spread codes. However, in the few locations per plant 19 where it's an issue engineering evaluations can be 20 conducted. And again, I'll get into that in a'little more 21 detail on the alternative methodology that we will be 22 discussing.
23 The other part that has to be addressed in 24 relation to doing a fire vulnerability is the relationship 25 of fire to the IPE.
Heritage Reporting Corporation (202) 628-4888 i
I
147 (n).
1- The fire itself doesn't create a new accident.
2 What it does-is, increase the probability of an existing
~
3 accident because it takes away. systems that you.had relied
'4 on.
5 If you go do a fire PRA or IDCOR methodology _you 6 get a certain reliability of the entire plant system. If 7 you then. superimpose fire on that, you decrease the 8 reliability of something you had assumed before.
9 As a consequence we have to tie fire directly as.
10 it's done with the IPE and that ties into Generic Letter 88-11 20 on the IPE which permits a' level 1 PRA to be done with a 12 few modifications to it and enhance IDCOP, or it also allows 13 other systematic methods found acceptable by the Staff which 14 means if the licensee wants to do any other methodology can 15 do so. So we have to come up with a fire methodology that 16 is acceptable or compatible with those because they're going 17 to perform the basis for the whole analysis.
18 In the area of the ALWRs we have tried to take the 19 lessons we have learned in all the current generation of 20 fires, all the Appendix R reviews, and everything we have 21 been doing for the past 14 years since Browns Ferry and, 22 hopefully, eliminate the majority of them.
23 We came up with a new statement that has gone to 24 all the current applicants and it basically says that plants 25 must be capable of safe shutdown, assuming a total loss of l
O Heritage Reporting (202) 628-4888 Corporation l
l l
l l
I 148 1 any one fire area -- and a fire area is defined as separated 2 by a three-hour barrier -- three-hour boundary. Assuming no 3 operator reentry and we exclude reactor containment building 4 from that with a specific review of locations where 5 components are close together.
6 This basically winds up in eliminating a 20 feet 7 separation criteria and also eliminating any redundant 8 trains from being in any one fire area. So that you get rid 9 of one fire, being able to destroy redundant trains, 10 MR. MICHELSON: You're able to do that in the 11 instruments rooms and switch gear rooms as well.
12 MR. MCCRACKEN: Yes. You have, like, dual A and B 13 trained cable spreading rooms, switch gear rooms, same 14 thing, yes.
()
15 MR. MICHELSON: Now, you have those spreading 16 rooms which are generally above and below the room 17 containing the cabinets, but are you also requiring that the 18 room containing the cabinets be divided into train As 19 reactor protection and train B.
20 MR. MCCRACKEN: With the exception of when you get 21 into the control room fire area. And the control room fire 22 area things obviously have to come together in the control 23 room fire area.
24 MR. MICH31 SG1: Define the control room fire area?
25 Does that mean the control room itself?
Heritage Reporting Corporation (202) 628-4888
l-ls l 149
.1 MR. MCCRACKEN: It's the control room itself plus.
.(_.)
2 whatever' switch gears or cabinets are involved in'there.
- 3. But.when they dolthat, they then have an. alternate shutdown 4 capability which is totally wired independently and remote
.5 so it doesn't come through that. fire area.
6 MR. MICHELSON: Now, the reactor protection 7 cabinets might'be located in a room adjacent to the' control 8 room, is that still the control room fire area?
9 MR. MCCRACKEN: Yes, that would still be the 10 control room fire area.
11 MR. MICHELSON: Even though it's a separate room.
12 MR. MCCRACKEN: Right.
13 It would not be -- they could put a three-hour 7 14 barrier in there and make another one if they chose to,-
15 sure.
16 MR. MICHELSON: But it's-all one -- even though 17 it's subdivided it's considered-one --
18 MR. MCCRACKEN: Even though there are walls that 19 are not three-hour barriers, it's still the same fire area.
20 DR. SIESS: But, Conrad, you just said that the 21 remote shutdown area is completely separate from the control
- 22. room and there is no connection to it, et cetera, et cetera; 23 right?
24 MR. MCCRACKEN: Right.
25 DR. SIESS: We heard yesterday on the multiple
()- Heritage Reporting Corporation (202) 628-4888 i
150 1 system responses program some potential scenarios of
-2 interactions between fire in the control room disable' things 3 before you could.get to the remote shutdown.
4 And under the worst possible conditions they were 5 getting core melt probabilities of 10 to the minus 4. Now 6 that was assuming something happened with _t having a 7 mechanism part to happen.
B. MR. MCCRACKEN: Right.
9 DR. SIESS: When they looked at a PRA they got 10 down to the 10 to the minus 6 range. But that suggested it 11 may not be quite as independent as you made it.
12- MR. MCCRACKEN: No , that suggests if it is not 13 independent that the core melt frequency could be 10 to the 14 minus 4. But as long as you can clearly show that it is
()
15 independent, then the core melt frequency goes down to that 16 10 to the minus 6 number you're talking about.
17 MR. MICHELSON: Is it easy to show for new plants 18 that that would be the case?
19 MR. MCCRACKEN: For new plants we're talking 20 ALWRs.
21 MR. MICHELSON: Yes, they somehow have to still be 22 connected to devices in the control room, but you have to 23 separate that connection.
24 MR. MCCRACKEN: What you do is you take your lead 25 off much closer to the instrument or device you're trying to
() Heritage Reporting Corporation (202) 628-4888 i
-151
.(=1 control instead'of'taking it off from the control room.
2' MR. MICHELSON: But that will be a-part of the 3 requirement for the advanced lightwater reactor.
4- Mh. MCCRACKEN: Yes.
5 MR. MICHELSON: Thank you, n .
6 MR. MCCRACKEN: .And we're also. requiring that they 7 address smoke and heat in the ALWRs. And we have agreement 8- in general with -- GE has agreed, period, they said, yes.
9 And Westinghouse is agreeing and we're discussing it.
10 MR. MICHELSON: Now, what do you -- for advanced 11 lightwater reactors, what kind of assumptions will be 12 required concerning what happens to equipment out in the 13 building when the control cabinets in the control room area
'{} 14 15 are being heated up and start to malfunction.
Admittedly, the remote location must be able to 16 operate certain safe shutdown equipment, but there's, you 17 know, some things like relief valves that are already 18 opening and other valves that might be important that would 19 be closed for too long a time while it takes the time -- it 20 does take time to get to the remote shutdown area and set'it 21 up and whatever.
22 What kind of rules are going to be written for 23 advanced lightwater reactors to cover that sort of thing?
24 MR. MCCRACKEN: I can' t tell you. You're beyond 25 the areas that I work in.
() Heritage Reporting Corporation (202) 628-4888
152
,q
(/ 1 MR. MICHELSON: But I thought that was all related 2 to whether or not you can properly survive a fire.
3 MR. MCCRACKEN: The determination on what the 4 equipment can handle under equipment qualification is not 5 part of what we're doing in the fire side.
6 MR. MICHELSON: But it would be part of what the 7 vendor would be required to demonstrate to show that he has 8 really a safe shutdown capability.
9 MR. MCCRACKEN: Yes.
10 MR. MICHELSON: But it would be somebody else look 11 into.
12 MR. MCCRACKEN: Right.
13 And what the qualifications of that would be --
14 MR. MICHELSON: Is that going to be written down
()
15 somehow so that the ABWR and others understand that's one of 16 the rules?
17 MR. MCCRACKEN: I know that there are people who 18 have reviewed and discussed that issue, but they were the 19 I&C branch, and I'll be honest, I ignored it when they were 20 talking about it.
21 The course of action that we are currently 22 involved in to identify fire vulnerabilities: our number one 23 priority is to get examinatic conducted to identify 24 vulnerabilities. We are at a point now where we think 25 sufficient information exists and we can do a reasonable 1
() Heritage Reporting (202) 628-4888 Corporation
I i
153
() 1 ! search.for vulnerabilities _beyond the. regulations and we're I
2 proceeding to dc ' t as our number one priority.
3 As we do this and go through and do the' 4; ' examinations we will do a cross-check of findings, so if we l i
5 find one issue at one plant we will see'if it exists at 6 other plants. Or if we find a problem at multiple plants, 7 we'll see why the other plants haven't identified it, t 8 So we will definitely have a cross-checked scheme'
-9 as we go through these to make sure that the data for one 10 plant applies back to another plant, and if necessary we can 11 issue another Generic Letter or whatever we need to do.
12 MR. MICHELSON: But are you doing this work or is 13 the utility doing it?
14 MR. MCCRACKEN: The utility will do the 15 examinations, but we're going to review them all.
16 MR. MICHELSON: So what you really mean by "we" is 17 that, we will review the IPE results that the utility has?
18 MR. MCCRACKEN: Correct.
19 MR. MICHELSON: You won't participate in the 20 walkdown itself.
21 MR. MCCRACKEN: I think based on what we're doing 22 now we will participate in some of them~to ensure ourselves, 23 especially the early ones, that we're satisfied with what's 24 going on.
25 MR. MICHELSON: Now, the guidance that you're
. Beritage Reporting Corporation (202) 628-4888
n ..
?'
(,
7,-); . 1~ developing is guidance for the people that'are'doing the 2 walkdowns; is that correct?
3 MR. MCCRACKEN: That's correct.
o
- 4. MR. MICHELSON: Will you develop other kinds of R 5 guidance for the people who are going to review the results?
6- MR. MCCRACKEN: The people developing the guidance 7 will be some of the people who are going to review ~the 8 :results, j
9 MR. MICHELSON: Okay. So they will be informed.
10 MR. MCCRACKEN: Yes.
i 11 The Staff is working with NUMARC and EPRI to 12 develop an acceptable methodology. Our current schedule is j 13 by the end of calendar '89 and it's to be tested on two -l 14 plants: a BWR and PWR by 1990.
~
15 This particular methodology,~there are two areas i
16 in it that are going to take a little more time. The !
1 17 updating of the data base. We're trying to update the' total ;
1 18 fire data base. To do that industry is going to use the EEI 19 data base instead of the NRC LER data base, because LERa 20 only report a very small percentage of the total number of l l
21 fires that reach a certain level of significance. And the ;
1 22 EEI data base reports all fires. So they have a much larger l 23 data base to draw from on location and severity of fires.
24 MR. MICHELSON: I guess I'll have to show my 25 ignorance. What is the EI data base?
O Heritage Reporting Corporation (202) 628-4888
L 155 1,e~ / . . .
r '2 'MR. MICHELSON: Oh, EEI, okay.
l- ' -3 Now that data base, is it presently. receiving alli 4_ fire reports?
l 5- MR. MCCRACKEN: They receive virtually allcfire l: 6 reports. Other than maybe trash cans.
7 MR. MICHELSON: It's a voluntary process,.of 8 course.
9 MR. MCCRACKEN: Yes. But from what they've said,.
10 they're getting pretty' good input.
11 MR. MICHELSON: Have you ever verified how well 12 it's working by.doing a'few spot checks?
13 MR. MCCRACKEN: I have seen data from a couple of 14 plants which far exceeds that we get on LERs.
15 MR. MICHELSON: No, but I'm wondering, is there a 16 reasonably comfortable feeling that virtually all the fires
- 17. are in that data base?
18 MR. MCCRACKEN: I think there are enough when 19 you're trying to show number of fires per plant per year, ;
I 20 that it's a good data base. I don't have any trouble with 21 that.
22 I'm sure there are a few plants that are reporting 23 nothing.
24 MR. MICHELSON: Now, the data base which I'm a 25 little acquainted with is the one that's compiled as a NUREG l
(]) Heritage Reporting (202) 628-4888 Corporation i
l
- - _ _ _ - _ . - _ _ _ _ - _ _ \
, 156 1 .and it's on computer disks,;that's not an EEI data base as 2 such.
.3 MR. MCCRACKEN: No. But that-is the data base
.4- that will-be updated.
5 MR. MICHELSON: Yes.
6 But that data base, how does it corapare with the 7 EEI? What fraction?
8 MR. MCCRACKEN: It's smaller.and it ended in -- I 9 think the last date in there was 1984.
10 MR. MICHELSON: But for the years covered what 11 fraction do I think I'm looking at? Do you have~any feel?
12 I' thought it was reasonably complete, but you're 13 saying there is an even more complete one.
14 Is this a proprietary data base, the EEI?
15 MR. MCCRACKEN: Not when they have it done it 16 won't be, no.
17 MR. MICHELSON: Is it on computer disks or is it 18 just on paper?
19 MR MCCRACKEN: I don't know. All I've seen are 20 paper, but I don't know how they've got it available.
21 MR. MICHELSON: Now, you don't know what fraction, 22 though, do you?
23 MR. MCCRACKEN: No, and I'd rather not guess at a 24 number.
25 MR. CARROLL: I have never heard of the EEI data Heritage Reporting Corporation O-(202) 628-4888
\
157 4 1 base coming'from the utility industry., and I expectithat I 3
2 would.
3' EWho is doing it? What committees?
4 MR. MCCRACKEN: I don' t- know what. subcommittee.
.5L NUMARC and EPRI were discussing it.
6 MR. CARROLL: Has it been in existence a-long' time 7 or is it something fairly recent?
8 MR. MCCRACKEN: They've been talking to usLabout
~
9 itIfor.perhapsia-year. How much prior to that it was in 10 existence, I'm not sure.
~11 MR. MICHELSON: I guess I wasn't showing my 12 ignorance'then, was I.
13 MR. CARROLL: No.
14 MR. MICHELSON: I thought maybe it just slipped:by.
(
15 me somehow. I never heard of it.
16 MR. CARROLL: It would be very involved in 17 reporting on various kinds of things to EEI.
18 MR. MICHELSON: Maybe I could ask -- just 19 interrupt a moment. What reporting system do you think 20 utilities use to go beyond what might require an LER? Is 21 there any reporting that you're aware of?
22 DR. SHEWMON: Do the insurance companies follow 23 this?
24 MR. CARROLL: I don't know.
25 MR. MCCRACKEN: I think part of the EEI data base Heritage Reporting Corporation (202) 628-4888
j 1
158
(( } 1 is. coming from the insurance company reports. The state 2 required insurance company reports on fires. But I said, 3 think.
4 MR. CARROLL: Well, is this an ad hoc EEI effort 5 or is it an existing program?
6 MR. MCCRACKEN: It's, to me, I think an existing 7 program based on what they've said. But again, I. haven't 8 reviewed it. I've seen some data.
9 MR. CARROLL: Okay.
10 MR. MCCRACKEN: So I assume they have a program or )
11 they couldn't have shown me the data.
12 But part of that we'll review. Part of what we 13 will do as we're going through this is review their data rs 14 base to be sure that we agree with the data base.
(
15 The available methodologies for fire will be 16 basically the NUREG-1150 Sandia methodology, which is 17 compatible with plants that have conducted a PRA. That's 18 the one that was discussed in detail yesterday.
19 And the alternative methodologies, as I said 20 earlier, has to be compatible with the enhanced IDCOR and 21 other methodologies, other to be defined later.
1 22 MR. MICHELSON: Let me interrupt again for a 23 moment. The Sandia methodology, I thought I heard 24 yesterday, they said their modifications to compburn 3 were 25 proprietary, if I understood it correctly. They said they
[ Heritage Reporting Corporation (202) 628-4888 I
... s h'
1 .,
159
~
'1' had'a' proprietary. The other versions were available to the
..()l 2- ' lice,nsees', but not their version.
3 Did I misunderstand?
l3 4 MR. MCCRACKEN: No, I think they said the 1
j- 5 modifications they made,were listed in the work they did.
6 Is that correct, John?
7 MR. MICHELSON: So there is no proprietary version 8 of --
9 MR. MCCRACKEN: I don't know how it can be 10 proprietary'if'it was done under government contract.
11 MR. MICHELSON: I just wondered, because you
-12 couldn't say the licensees use their methodology unless that 13 code is available to~them.
-m 14 MR. MCCRACKEN: Compburn 3 is an industry
.-( )
15' developed code initially. And if we modify it.under a 16 government contract -- I didn't hear that yesterday.
17 MR. MICHELSON: Sam verified that that's what.they 18 said, it was not available to other people.
19 MR. MCCRACKEN: He may have said it wasn't 20 available yet or it hasn't been put out yet.
21 MR. MICHELSON: I didn't pursue it yesterday 22 because I didn't want to argue about why isn't it available 23 and so forth. But you might want to look into that because 24 if we're saying they're going to use their methodology, then 25 we need to make that available.
f O Heritage Reporting Corporation (202) 628-4888 i
- _ _ =_--___- ___-_ _- _ _ i
l 160-l f~
D) . l' MR.-MCCRACKEN: Yes.
.4
'2 MR. FARMER: I just was going to add'a. comment.
3- Farmer from NRC.
4 The compburn code.is available and the Sandia i L5 modifications are available But the Sandia modifications 6 are not adequately documented so that it would require 7 'somebody to pick.up both the Sandia data and the code and do 8 considerable work to factor the modifications.
9 MR..MICHELSON: Well, they must have done that
- 10. work already, of course, to use it the way they do, but
~
11 maybe the report writing hasn't been done.
12 MR. FARMER: They've done it and it's in their 13 files, but it's not in the form --
14 }G1. MICHELSON: So you have to spend some money to
()
15 get it ready. But you would have.to do that to do what 16 we're saying here, using their methodology. The licensee 17 would have to get that information.
18 MR. MCCRACKEN: Well, the NUMARC and EPRI 19 committee would have to get the information.
20 MR. MICHELSON: Yes.
21 MR. MCCRACKEN: Right.
22 DR. SHEWMON: I've got a letter here that was 23 Beckjord -- sorry, Morris to Beckjord in November of ' 88.
24 And it says: "The shortcomings of the compburn fire code 25 can be summarized by following the peer review comments of
( Heritage Reporting Corporation (202} 628-4888
_-_________ _ ___ _ O
161 O
lss' 1' :the fire risk scoping study submitted by the EEI Fire 2 -Protection Committee."
- 3. And they say: "The entire report is-based on 4 ' failure of compburn 3 to agree with available data or lack 5 of sufficient data to support ccO.2:a 3."
6 As I reread this two or three times more it is not I I
7 quite clear to me, was the EEI evaluated -- was some review l 8 group evaluating EEI's proposal or did EEI set up a review 9 group for wherever compburn 3 came from? ,
i 10 MR. MCCRACKEN: There was a review group that ,
)
11 looked at the fire risk scoping study results and EEI' ;
12 members were part of that group. And they commented on the l 13 code and the areas of the code where there were
() 14 uncertainties.
15 DR. SHEWMON: But where compburn came from, we i 16 aren't sure. But you do know that the Sandia people have 'I 17 reworked it under public money.
18 MR. MCCRACKEN: Yes. ;
19 Compburn came from UCLA. We know where it came 20 from. j i
21 DR. SHEWMON: Okay. j i
22 DR. KERR: We know who the culprits are. l 23 DR. CATTON: The person who put the code together ;
24 comes from the PRA school, Georgia Postalocus. So you can 1 25 come to your own conclusions about the physics behind the l Heritage Reporting Corporation (202) 628-4888 1
l
R r 1 1
I 162 L J
. .e- C d j) 1 modeling' effort.
]
)
h SE MR!. MCCRACKEN: But-again I want to emphasize: we 3 know there-are limitations with the modified compburn 3 - -
4 and I'll .try to address a little bit later how we ' intend to 1 5 handle it.
6 'The' applicable fire risk. scoping study.results are.
7 to be included in the methodology. In other words, we 8 identified through the fire risk scoping studies that there 9 are areas of potential vulnerability. And we feel the best 10- way to addreas.those is to include in the methodology a
~
11 means for each plant to assess what that.means to their 12 specific facility.
13 MR. MICHELSON: By methodology do you now mean
-14 those IPEEE guidelines that we talked about?
(])
15- MR. MCCRACKEN: Right.
16 The simplified methodology or advanced methodology
.17 or whatever we're going to come up with from NUMARC and 18 EPRI.
19 The way in general that we will be doing that --
- 20. and'again, this is an outline of what we' re going to do it.
'21 -We've discussed it with industry, we had a meeting on Monday 22 this week. The final documentation is not ready yet. We 23 will anticipate having a rough draft of the guidelines 24 probably in mid to end of September and then final 25 guidelines by the end of December.
Heritage Reporting Corporation
( (202) 628-4888
163 1 In the area of analytical codes which is one of .
2 the areas identified as a potential vulnerability, we have l
3 determined their adequate to search, understanding that they .
4 do have limitations. They cannot give us all the answers we 5 would like.
6 To do that we're going to use the codes and 7 develop reference tables using compburn 3 and MAGIC which is 8 a French code similar and engineering judgment. The intent 9 is, we're going to go in -- when I say "we" industry is 10 going to go in and we're going to review what they're doing.
11 Look at very specific configurations for fire areas. Develop 12 a whole series of tables that show if you have a fire of a 13 certain source term over here, what temperature you can 14 anticipate getting at another end of a room.
()
15 And the idea is to eliminate the computer 16 uncertainties by, first, run the computer code, set up a 17 whole bunch of rooms, and then go into an engineering 18 evaluation and see if it looks logical. Look at the type of ..
19 equipment you have. The vulnerability of that equipment.
20 So that the practitioner trying to implement this will be 21 able to look in a location and come up with the closest 22 table to match his condition and make an assessment of the 23 time he has to suppress a fire before equipment reaches -
24 critical temperature or, in fact, he can't suppress it.
25 In some locations you may find you can't suppress
( Heritage Reporting Corporation (202) 628-4888
164 1 and then you:have to do another means of taking care of it 2 to eliminate,the vulnerability.
l L 3 DR. CATTON: Do you know the critical temperature l'
4- for equipment?
5 MR. MCCRACKEN: We're going to use the best 6 engineering judgment with the data available to establish 7 . what critical temperatures are for certain types of 8 equipment.
~9 DR. CATTON: You haven't done this yet, though.
10 MR. MCCRACKEN: The data is avsilable; we haven't 11 put it together. That will be part of the table.
l 12 It is an area where there, again, are l
l 13 uncertainties involved and you have to use systems people 14 who understand equipment and fire protection engineers and
.O- 15 PRA people all together to come up with the best assessment 16 of what it's going to be.
17 MR. MICHELSON: Now, when you're evaluating that 18 -critical temperature is it from the viewpoint of continuing 19 operability?
20 MR. MCCRACKEN: Yes.
21 MR. MICHELSON: From the viewpoint of potential 22 undesirable system interaction? See, there are various 23 critical temperatures according to which problem you're 24 worried about.
25 MR. MCCRACKEN: It's functionality.
Heritage Reporting Corporation
\
(202) 628-4888
l 4 >
165 I
. (( ) .1 MR. MICHELSON: The fact is, the first problem --
2 the.first critical point might be when you're getting 3 -undesirable' system interactions, everything is working fine,
~
4 it's just doing!what you don't want.it to do. And that may 5 occur well before the system ceases to function adequately 6 to perform the final safety function of ths device.
7 MR. MCCRACKEN: The intent is to try to define 8 functionality. We're not trying to define when a cable will 9 Eburn. That's not going to help anybody.
10 MR. MICHELSON: In preparing these charts now to 11 look at temperatures around an area, those will be on t v.e 12 assumption of no suppression; is.that-right?
13 MR. MCCRACKEN: Correct.
14 And what you're doing is, you're looking at how
.O 15 far you can get before you have to suppress; and then you 16 make a determination of how soon you can suppress.
17 MR. MICHELSON: How do we determine what happens-18 to the temperatures around the room when we suddenly do 19 start suppressing the fire? The temperatures, of course, 20 don't -- how do we know how the temperatures behaves after 21 we start suppression?
22 Is the assumption that as soon as you start 23 suppressing the temperature goes back to ndrmal or what does 24 the reviewer assume?
25 MR. MCCRACKEN: We're not going to assume an f'. Heritage Reporting Corporation (202) 628-4888
'166 l' , ' instantaneous suppression. We're going to -- that's why you 2 have the fire expert as part of this. It's time to be able 3 to suppress.a fire; not to start putting water or-4 CO2 --
5 MR. MICHELSON: Will there be some other kind of 6 -guidance tables or something?
7- MR. MCCRACKEN: That time will be factored in. In 8 othir words, suppression time is not when somebody arrives 9 or system-initiates. Suppression time is when you can, in 10 fact, put out the fire.
11 MR. MICHELSON: But in terms of. evaluating 12- equipment in a particular area, that's susceptible to 13 certain temperatures, how do you decide what the profile of
-14 tempera'ture looks like?
15- MR. MCCRACKEN: Based on'our preliminary 16 discussions we would assume that the temperature would just 17 remain constant once you initiate suppression and would not 18- start decreasing until you are done with' suppression.
19 MR. MICHELSON: I see.
20 I mean, there are various assumptions and I just 21 wonder what the guidance would be.
22 MR. MCCRACKEN: Well, based on preliminary that's 23 how we thought we would go with it.
24 MR. MICHELSON: Okay.
25 DR. CATTON: Both the codes that you refer to, Heritage Reporting Corporation (202) 628-4888
167
, j( ). il- both the'compburn 3 and MAGIC are two zone codes. You've 21 ~got'a. hot layer on the roof and the rest'is cold. What are-L3 you going to do in.between? Because the critical 4 temperature'for equipment might well be-200 degrees C or 150 5 degrees' Fahrenheit or something.
6 How are you' going to distribute the temperature?
7- I mean, what are you going to do? Are you going to' guess at 8 a profile.
D MR. MCCRACKEN: We're going to, based on 10 experience in-fires, with: fire protection engineers
'll reviewing where fires have occurred in similar types of 12 locations, make an assessment. If the higher temperature.is 13 bere,'what we think the others could be. There are
' 14 uncertainties in that; we know that.
15 But again remember, what we're trying'to 16 accomplish is to identify vulnerabilities. If we come up 17 with something that says, this' component is going to be in 18 trouble in 16 minutes, and we need to suppress in 15 19 minutes;'that's a vulnerability.
20 If we come up with, hey, this won't get in trouble 21 for 30 minutes'and we can suppress in 10 minutes.
22 DR. CATTON: It's marginal.
23 MR. MCCRACKEN: Well, it's a lot better.
24 DR. CATTON: That's true.
25 MR. MCCRACKEN: There's going to be a lot of Heritage Reporting Corporation (202) 628-4888 o_ ___z __
168 f( ) 1 judgment involved in it.
2 DR. CATTON: That's certainly true.
3 MR. MCCRACKEN: The issue of seismic fire 4 interactions raised in the fire risk scoping study will be 1 5 handled as the scoping study recommends, through a 6 procedurally directive walkdown and there will be very 7 specific procedures written on how you do it. What you need 8 to look for. And where they should and how you correct 9 them.
10 MR. MICHELSON: Those procedures will also be a 11 part of this package that is due by the end of the year?
12 MR. MCCRACKEN: Those particular procedures may 13 not be in this specific package but they will be in the f-~ 14 seismic package.
15 MR. MICHELSON: But is that also by the end of the 16 year?
17 MR. MCCRACKEN: Their schedule, I believe, is the 18 same as our schedule, but I can't guarantee that's a true 19 statement. We're supposed to get done the same time. I 20 can't guarantee they're working, you know, the same rate 21 that we are.
22 DR. SHEWMON: Do these fires or the great majority 23 of them stem from people violating administrative 24 procedures; and thus, taking a combustible material into a 25 place where the manager said they will never be?
l
\
l , Heritage Reporting Corporation k (202) 628-4888
_1 MR. MCCRACKEN: No.
2 DR. SHEWMON: What is the main ~ source?-
3- MR. MCCRACKEN: The main source of fires are 4 welding and burning, electrical comes next.
l l
5 DR. SHEWMON: Welding and burning, I hava a pretty 6 good idea what welding is. Is this stuff that's 7 inadvertently set up or people setting up bonfires that 8 burn?
9 MR. MCCRACKEN: No. Somebody is welding up here 10- and they got. sparks going down and they initiate a fire or 11 .using a cutting torch. You're using a torch or cutting 12 something out-and you got sparks going down. I mean, that's 13 why you have fire watches every time.you do this.
14 MR. CARROLL: I can't recall a significant fire 15 that's.ever resulted from that, though.
16 MR. MCCRACKEN: Great, that's why there are fire 17 watches there.
18 19
-20 21 22 23 24 25 Heritage Reporting Corporation (202) 628-4888
170 l' D 1 MR. MICHELSON: There was a significant one at
%./
2 Brown's Ferry about two years ago inside a containment when 3 they were doing such operations, and that burned quite a bit 4 of material. But of course there was the suspicion that 5 there might have been extra flammables around.
6 DR. SHEWMON: That's not the candle fire.
7 MR. MICHELSON: No , no, no. The one about two 8 years ago, it burned a significant amount of cabling and 9 cable trays.
10 MR. McCRACKEN: This is one where there was 11 substantial evidence that there could have been arson.
12 DR. KERR: It also was not an operating plant.
13 MR. MICHELSON: Well, in a sense I guess not.
14 Legally it was.
%/
-)
15 MR. CARROLL: Also it was a very unique plant in 16 terms of the insulation on the cables.
17 MR. McCRACKEN: Correct. The cable insulation 18 there, because it is noted, is a little more flammable than 19 some others.
20 The issue of fire barrier qualification.
l 21 Individual plants have to justify their assumptions when 22 they tell us their fire barriers will withstand it.
23 The reason for that is that over the past several i 24 years we bave had a number of information notices on 25 degradation of fire barrier seals, inoperability of dampers.
l l
[ Heritage Reporting Corporation
\-] (202) 628-4888
171 1 And we need them to go back and verify when they do this 2 that in fact-they have read and implemented the things
~3 identified in information notices that-would correct this 4 problem. .
5 .MR. CARROLL: Have you questioned the assumption 6 of a three-hour.firewall? What is magic about three hours?
7 MR. McCRACKEN: Absolutely nothing is magic about 8 it. It was selected because it happened to be a 9 standardized test.
11 0 There are certainly people who have argued that we 11 don't need three hours barriers in here because the normal 1:2 maximum, the' average time for a fire brigade to reach an 13 area is 20 minutes. And having a three-hour barrier is a 14 big overkill.
(} .
15 The response to that is we picked three hours.
16 Three hours is there. There is no reason to change it.
17 DR. SHEWMON: Don't ask us why. It is our policy.
18 MR. CARROLL: They don't last three hours anyway, 19 do they, according to Sandia?
20 MR. McCRACKEN: A three hour barrier is based on a 21 standardized test with a very significant heat source. A 22 barrier that withstands that under a normal fire in most 23 areas of the nuclear power plant would last a lot longer, 24 but it could last less.
25 I mean, a three-hour barrier could last two and a Heritage Reporting Corporation (202) 628-4888
4 i
172
() I half hours. But there is a large margin. A three-hour
.2 barrier doesn't mean at an end to three hours suddenly this 3 thing is breached.
4 DR. SHEWMON: What is the criterion for failure?
~
5- A breach, or just temperature rise?
L 6 MR. McCRACKEN: The criterion for barrier failure 7 is a certain temperature on the outside of it.
8 MR. MICHELSON: That's about how much, 250 or 370?
9 It is a fairly elevated temperature.
10 MR. McCRACKEN: It's fairly high.
11 MR. MICHELSON: Much higher'than equipment would 12 already be damaged from the operability viewpoint.
13 MRt McCRACKEN: Yes. I forget what.it was.
14 MR. MICHELSON: This is'for fire ignition really, 15 is the purpose.
16 DR. SIESS: Is it air temperature on the other 17 side?
18 MR. McCRACKEN: It is air temperature within 19 proximity, and I forget how many inches. It is fairly 20 close.
21 MR. CARROLL: A heat source on the hot side of the 22 wall is a hot heat source.
23 MR. McCRACKEN: Correct.
24 The next item is manual fire-fighting 25 effectiveness. And what this addresses is your ability of
() Heritage Reporting Corporation (202) 628-4888
-m.__ _ _ _ _
la 173 q-
'A ) . ll your fire brigades to respond.
2 'And'again that has to be done on an individusi 3 plant basis, and they.have to justify their assumptions. 'If 4- they say their fire brigade can reach a certain area in 5 seven' minutes, then they have to prove that they in fact can 6 reach that area in seven minutes and be there prepared to 7 put out a fire.
8 The total equipment survival issue is one of will 9 combustion products cause a problem. This is an issue that 10 has not'yet been totally resolved. There is some 11 information.available on it but not a whole lot. Its effect 12 on electronic equipment.
13 It is the effect also of fire suppression system 14 on safe shutdown equipment, and the'way we intend to handle
()
15 this, it is also part of the Generic Issue 57' resolution.
16 The people in charge of Generic Issue 57, the task 17 manager, attends all the Fire Subcommittee meetings; he 18 attends all the NUMARC EPRI meetings that we have, to ensure ,
i 19 that what we are doing is going to be compatible.
20 The intent.through this particular area is that we 21 will have a plant walkdown that will include an 22 identification of all areas that automatic suppression or 23 inadvertent suppression of systems could cause a problem, 24 and identify it as a vulnerability.
25 If we then include under Generic Issue 57 that Heritage Reporting Corporation (202) 628-4888 1
4 174 l l ,,
(-) I that particular type of suppressant causes the 2 vulnerability, we will have it identified and know exactly l
3 where to go to see what we are going to do to fix it.
4 MR. MICHELSOll: It is not still quite clear to me 5 how you assure that your actual walkdowns are compatible 6 with the resolution of 57 since the walkdowns come first.
7 MR. McCRACKEN: Because the walkdowns'will 8 identify, through this process, through the entire process 9 we are going through, the methodology we are going to use, 10 will identify all trains or areas that you have to have to 11 achieve safe shutdown.
12 MR. MICHELSON: But how does that relate to the 13 resolution of 57 once it is resolved, which might be a 14 couple of years after the licensee has already done his
[v)
15 walkdowns and written off on the problem?
16 MR. McCRACKEN: What it does is it identifies 17 every area that you have to have; it identifies the 18 suppression systems in there, the type of suppression 19 system, so if you then find there is a problem with that 20 particular type of suppression system, you have already got 21 it there, you know its potential effect if it doesn't work, 22 and you can make an assessment as to whether you need to do 23 something with it.
24 MR. MICHELSON: I guess that has not helped me a 25 bit, because I don't know today what the resolution of GI 57 m
k_) Heritage Reporting Corporation (202) 628-4888 i
l[
t 175 1 is going to be. If I were doing-a walkdown, I still.would 2- not know what the resolution will be.
3 MR. McCRACKEN: The resolution of'GI 57 will be
-4 something that will say either this particular type of_-
5 suppression system is susceptible to inadvertent actuation 6- or susceptible to unplanned actuation and the consequences 7 could occur this many times.
'8- You then look at a room'you have and say okay, if
.9 I have that initiate, is it going to cause me a problem?
10 MR. MICHELSON: Yes. I tAink I understand the 11 process. 'It just is not clear to me though today how you
'12 know what that final process is going to be, that 13' constitutes the resolution.
14 ' MR. McCRACKEN: I'm not sure what it will be. It
(}
15 may be turn off the suppression system.
16 MR. MICHELSON: I guess what we are saying is that 17 we will let the resolution.be guided by the walkdown and 18 their results and make sure that it does not ask for any 19 more than we already have done.
20 Is that sort of what you are saying?
21 MR. McCRACKEN: Right. Yes. Something like that.
22 MR. MICHELSON: A strange way to take a 23 fundamental issue and resolve it by making sure that it just ;
24 does whatever you --
.25 MR. McCRACKEN: The schedule for Generic Issue 57
() Heritage Reporting (202) 628-4888 Corporation
176 1 is about two years behind when we intend to be done.
(^)T u
2 MR. MICHELSON: Yes.
3 MR. McCRACKEN: So I can't very well wait on it to 4 decide what to do.
5 MR. MICHELSON: I would be much more comfortable 6 if GI 57 is resolved today and just simply says we will use 7 the IPEEE guidelines and that is the resolution. If you do 8 it right, you will resolve the issue. That I would 9 understand.
10 MR. McCRACKEN: That's fine with me.
11 V". . MICHELSON: But the other process is a little, l
12 the logic escapes me, I guess.
13 MR. McCRACKEN: And the other issue which we g- 14 talked a little b3t about, control system interactions, this q-)
15 is the issue that was identified where Dr. Siess was talking 16 about the probability of 10 to the minus 4, if you have 17 interactions, of getting core melt, or if you don't have 18 total separation between your alternate shutdown and control 19 room.
20 And again part of this is to ensure that you do 21 have it. Licensees will have to verify in fact that they do 22 have independent leads running separate from the fire area 23 that includes the control room so they in fact do have a 24 dedicated, alternate shutdown capability.
l-25 MR. MICHELSON: Now, maybe you said it and I just I~)
k/
Heritage Reporting Corporation (202) 628-4888
-A
i p 177 1 didn'.t pick up'on it. But.could you explain again what you 2' think the~ guidelines will say or-how they will cover.the 3 question of heat and smoke migration and so forth, other 4 than by these little sharp temperature distributions that 5 you are going to use --
6 MR. McCRACKEN: The guidelines will have some 7 general statements and examples on heat.and smoke migration 8 that will address such things as ventilation, the type of.
9- configuration you maintain your ventilation in doing a fire, 10 and say that you should look'at this for your criticel areas 11 or areas that you have to go'through to see that you have
-12 the best available system to mitigate smoke.
13 MR. MICHELSON: Will it also mention that you have gj 14 to think about what happens on the opposite side of fire
%,J -
15 barriers relative to elevated room temperatures and their 16 effect on operation?
17 MR. McCRACKEN: That is part of what you do in the 18 very beginning of this process is you are going through and 19 seeing which areas you need to examine.
20 MR. MICHELSON: You may have heat and smoke. Many 21 barriers are not true barriers of heat and smoke. They are 22 limited barriers, such as a door has cracks underneath it 23 and whatever.
24 MR. McCRACKEN: Yes. The ones currently installed 25 are not intended to be barriers for other than fire.
O Heritage Reporting Corporation (202) 628-4888
f 178 3,) - 1 .MR.~MICHELSON: Than fire propagation itself.
- 2. MR. McCRACKEN: Right. Yes.
3 MR. MICHELSON: And even then' limited to a certain 4- time.
5 MR. McCRACKEN: And the final discussion, which is 6 ss-t of just a summary of where we have been and how we got ,-
7 where we are, this was from an abbreviated agenda item that 8 the subcommittee had sent to us.
9 There was a 6-23-88 letter from me to the external 10 . events steering group which' basically provided the fire 11' s' subcommittee recommendations I talked about earlier which 12 was that a Level 1 PRA was adequate, and in fact'all plants 13 do have to'be examined.
{} 14 15 We had then a 12-28 letter-from Gillespie.of NRR to Beckjord in Research, stating what we 'elt about the 16 results from'the fire risk scoping study and that was that 17 we would incorporate the fire risk scoping study results 18 into the individual plant examinations.
19 We felt that was the best way to address them, and 20 stated that we do not foresee a current regulatory need for 21 -additional work.
22 Our basis for that particular statement is that see 23 believe with the modifications that have been made to plants 24 as a consequence of Appendix R and the other fire 25 regulations, and in addition conducting a vulnerability 0 erit ee aegerei e cerrer eie-(202) 628-4888
I 179 ff^$.
(,/ 1 search, realizing that anything identified over and above l I
2 that is going to have to be imposed by doing a backfit 1 4
3 analysis, our opinion is that we are not going to find very l
4 many issues that we will be able to justify through a 5 backfit analysis.
6 We think we really should have gotten virtually 7 every major issue by going through what we have already gone 8 through.
9 MR. CARROLL: When you say you do not fore,ee a 10 need for additional work, do you mean research-oriented 11 work?
12 MR. McCRACKEN: Right. We have to go through and 13 . conduct all the examinations.
( 14 MR. MICHELSON: Well, do you think that the
\
15 present examinations that have been done, in other words the 16 present work, in fact the present requirements for such 17 work, do you think they included items like heat and smoke 18 migration which you said you are going to account for in 19 your walkdowns and whatever?
20 MR. McCRACKEN: I'm not sure I understood your 21 question.
22 In the walkdown, we are going to address those to 23 the best of our ability with what we know today.
24 MR. MICHELSON: But that is a new requirement to .
l 25 address those in a walkdown for fire purposes. It wasn't
() Heritage Reporting Corporation (202) 628-4888
180
(_) 1 during an Appendix R kind of walkdown.
2 MR. McCRACKEN: That is correct. But industry is, 3 like I say, the majority of the work is guidelines are being 4 developed by industry in very close cooperation where we're 5 doing it.
6 MR. MICHELSON: I was just a little puzzled.
7 MR. McCRACKEN: And they have agreed that they 8 will be in there.
9 MR. MICHELSON: I just was a little puzzled about 10 the backfit argument. You could argue those are backfits 11 already, and over and above the present regulatory 12 requirements as prescribed for Appendix R.
13 MR. McCRACKEN: You could make that argument if we 14 were saying go do it. But they are developing the
(}
15 methodology and we are reviewing it.
16 MR. MICHELSON: You are saying they are doing it 17 voluntarily.
18 MR. McCRACKEN: Yes, they are doing it 19 voluntarily. And if you had raised that yesterday, I made 20 sure I had NUMARC and EPRI in the audience yesterday. But 21 they aren't here today.
22 MR. WYLIE: I guess the question, another way that 23 Carl was asking, was, you tnink that the basis for making 24 those studies, including smoke and heat, are based on 25 engineering judgment, what you are going to do --
() Heritage Reporting Corporation (202) 628-4888
181 1< MR. McCRACKEN: Yes.-
2 MR. WYLIE: -- are adequate without additional 3 research?
4 FDL . McCRACKEN: That is correct.
5 MR. WYLIE: That is your position?
6 MR. McCRACKEN: And that position I.think is a 7 reasonable' position, because we have roughly 1,000 operating 8 reactor years and we have not had a case of a fire that-9 could not be suppressed due to a problem with heatJand 10 smoke.
11 Firefighters have to live with heat and smoke.
'12 That's a feet of life.
13 DR. CATTON: But now you are worried about 11 4 equipment living with heat and smoke.
15 MR. McCRACKEN: Right.
16 DR. CATTON: And I think that is a different 17 story. And you are also dealing with stratified' flows and
- 18. rather complicated geometries. And if you indeed are going 19 to track heat and smoke, I think you have some more to do.
20 I am just not convinced that because you are 1
l 21 talking to firefighters that they understand these things.
22 MR. WYLIE: You don't think you can make an 23 engineering judgment about those-things?
24 DR. CATTON: You can always make an engineering 25 judgment. The question is whether --
Heritage Reporting Corporation O~ (202) 628-4888 1
l-182 g 1' - MR . WYLIE:- That is what he proposes to-do.
2 DR. CATTON: Well, I'm a little concerne d about 3 their ability to do it.
4 MR. WYLIE: But he's not going to do it himself.
5 DR. CATTON:. That's true.
6 MR. McCRACKEN: I'll buy that.
7 MR. MICHELSON: Of course-it was pointed-out 8 yesterday that the most significant fire we had which was at 9 Brown's Ferry was before Appendix R had been initiated and 10 therefore before al this automatic. fire suppression had been 11 put on which might perhaps be susceptible to inadvertent 12 actuation and therefore spread at least to the fire 13 challenge because equipment is getting wetted down which 14 might or might not survive well the process of wetting it
.O 15 down.
16 MR. McCRACKEN: I would think that --
17 MR. MICHELSON: -- so far to indicate in fact it-18 does not survive too well.
19 MR. McCRACKEN: I would think that one potential 20 coming out of here would be that in some areas there will be 21 automatic suppression systems that we told them to install 22 under Appendix R, that they are going to take out the 23 automatic feature and make it manual.
24 MR. MICHELSON: Change it to manual. Some 25 utilities have done this rather extensively. I assume NRC Heritage Reporting Corporation O-- (202) 628-4888 l
183 1 has reviewed these kinds of proposals and has approved them, 2 and it might be a potential answer.
3 The other side of the coin of course is the delay 4 then in mitigating the fire. But if I understand some of 5 what you said in your fire charts and so forth, you really 6 aren't assuming any mitigation anyhow while you are tracking 7 how hot the room is getting and so forth.
8 MR. McCRACKEN: That is correct.
9 MR. MICHELSON: So perhaps if you can show that 10 you have 20 minutes under that process, then manual might be-11 good enough.
12 MR. McCRACKEN: Then assuming an operator goes l 13 down to open the valve may not be a' bad assumption.
14- MR. MICHELSON:
() Yes.
15 DR. CATTON: When you use these two-zone models, 16 you don't have any mixing of the hot gases with the rest of 17 the room, which is certainly going to occur unless it is a 18 huge room.
19 And I just don't know how you are going to develop 20 the judgment for those kinds of things unless you have been 21 fooling around with recirculating flows in a confined 22 region. And that has not been NRC's business in the past, 23 So where is this engineering judgment going to come from?
24 MR. McCRACKEN: The people that are being brought 25 on as consultants by EPRI-NUMARC and their program are
( Heritage Reporting Corporation (202) 628-4888
184 (s 1 supposed to be able to provide us some insights into that.
2 DR. CATTON: That may be. And if that is the 3 case, then my concerns are without merit. Somehow I will 4 have to reserve judgment until I see who these consultants 5 are.
6 MR. McCRACKEN: That is reasonable.
7 DR. SHEWMON: Hopefully there will be some people 8 to work for insurance companies or somebody that goes out 9 and looks in areas to evaluate the damage that did result 10 from fires on a fairly regular basis. There certainly are 11 people that make their living that way.
12 MR. MICHELSON: They are not looking for system 13 interaction effects and that sort of thing except --
14 DR. SHEWMON: Carl, ths; are locking 2cr failures
(}
15 of equipment in areas that have had fire. Whether you want 16 to call it system interaction or whether they call it fire 17 damage, it didn't function as a result of a fire.
18 MR. MICHELSON: It s when it really did burn up.
19 DR. SHEWMON: Well, maybe, maybe not.
! 20 DR. SIESS: Some of these people who insure 21 nuclear power plants, don't you think they have some feeling 22 for what they are insuring?
23 MR. MICHELSON: I would not challenge that point 24 at all. I am just pointing out, make sure what --
25 DR. CATTON: I'm not sure, Chet.
l l
f)\
(, Heritage Reporting Corporation (202) 628-4888 l
185
('T
(,,e 1 MR. McCRACKEN: In the interactions I have had 2 with some of the insurance people at nuclear power plants, 3 which I have had on a relatively frequent basis, I have been 4 impressed with what they know. They have some pretty sharp 5 people there. They are not novices in what they are 6 ansuring.
7 MR. MICHELSON: Now, will the guidelines that we 8 see, they are really being generated I guess by NUMARC and 9 so forth? l 10 MR. McCRACKEN: Correct. ;
11 MR. MICHELSON: So they will reflect this learned 12 judgment or whatever, so when I see the quality of the 13 guidelines I can judge the quality of the work behind it, 14 which I think we have to see. I think we have to see the
(}
15 guidelines, because indeed they may be a sterling product.
16 MR. McCRACKEN: And the remaining item I had on my 17 agenda list was the SECY 89-170, which is the paper from RES 18 to the Commission, which we concurred in, and it informs the 19 Commission that the fire risk scoping study issues will be 20 addressed by the IPEEE.
21 And this is a document I guess you have to address 22 and we will write a letter on, and that the current 23 recommendation is no new fire research at this time, but it 24 will be considered based on the NUREG 1150 peer review, and 25 recommendations from ACRS.
() Heritage Reporting Corporation (202) 628-4888 l
l l'
V 106 i~
L 1 'And that, gentlemen, is all'that I have.
2 MR. MICHELSON: Any further questions?
3 MR. CARROLL: You mentioned, at some point in your
'4 presentation, that the major concern with smoke, 5 equipmentwise, was with electronic equipment. I think that 6 'is what you said.
7 MR. McCRACKEN: I said, yes, it's --
8 MR. CARROLL: I also worry about high-voltage 9 electrica1' equipment. You start setting things.up and you 10 can get flashovers, and that sort of thing. That has 11 happened in some real fires.
12 MR. McCRACKEN: If you get a lot of smoke into a 13 cabinet or something where you have a breaker, yes, I agree.
14 But usually you should not get a whole lot. The
{~
15 reason I said that is you should not get a lot of smoke into 16 that cabinet ~unless the fire is right there.
17 MR. CARROLL: Or a motor.
18- MR. McCRACKEN: Yes.
19 MR. MICHELSON: Any other questions?
20 (No response) 21 22 23 24 25
'O erie ee eerei e corror eie-(202) 628-4888 l
pi;i y.
L187: -1 Ol .
i Q '1 14R. MICHELSON:' .Our plan for.the time remaining, 2 and I am not sure'what our time remaining is, but our plan 3 -is to; read the first reading of-the mustard-colored draft.
l 4- .(Whereupon, et 4:05 p.m. the subcommittee
- '5 recessed,.to reconvene at 8:30 a.m. the following' day, 6 Friday,' July 14, 1989.)
7 8
.9
.10 11
-12.
- 13. .,.
24 LO -
- 15 -
16 17 18 19 20' 21 22 23 24 25:
Heritage Reporting Corporation (202) 628-4888
m .
ef K ,
lp ,
a[
1 CERTIFICATE 2
3 This is to certify'that the attached proceedings before the 4 United States Nuclear Regulatory Commission-in'the matter
-5 of: Advisory' Committee on Reactor Safeguards.
6 :Name: 351st. ACRS Meeting 7
8 Docket Number:
-9 Place: Beth-esda, Maryland 10 Date: June 14,.1989 11 were held as herein appears, and that this is.the original 12 transcript thereof for the file of the United States Nuclear 13 Regulatory Commission taken stenographically by me and,
~
_f 14 thereafter reduced to typewriting by me or under the.-
15 direction of the court reporting company, and that the 16~ transcript is a true and accurate record of the foregoing 17 proceedings.
18 /s/ naA gd4-19- (Signature typed) : Irwin Coffenbeffy
'20 Official Reporter 21 Heritage Reporting Corporation i
22 23 24 25 Heritage Reporting Corporation (202) 628-4888
_ _ - _ _ _ _ _ _ _ ________________________a
s i j! i1 i
O A
I S
D R
R U A
G S
E E E R
/
0 T I
F A
S R
I S
4 R E H
R O
D
/
- C T T C t H
C 4
3 9
O A 9 a N
, A N T E R
8 9
1 k
u a
A R
B 3-2 9
N G O N 3 y h S S 4
O I
I T O 1 B E o S A T
E Y di U S
N -
I E E L .
l N U a S e
. T .
h n D
I E T J o S K S E I
M G
N h
P
. R M I _
C P O R -
U I C E E
M S
Y R
O N
I G
N S
I I E V
E D A
S" O
lllll l _
1 1l 0
1 _
E D_
1 L
Y S _
F ,
I E 1 T R 6 -
N A 1 A 1 _
U S -
Q E R G C F D N / F N A G A _
A H E T .
C R S E U _
C F N D -
N I E E , P
- . U ) T O _
S Q P R L .
E E R O E V S S P V I ( E S E T N R E D C G N G E I A D N D J S L E A N D B E P H H A N O D S C U S W I P
1 6)
O G CS E L R N I E I B R 1 3 .
G I MC V U S 1 8 K W S O E P R R2 C O I R R 0 A B
0 L
L O
F EP S
F G N
D R
A D
N A
S E
I D
O F
S C 8
/ 9 G1 E(
4 OI D Y U N R
- E S N D T O UN A H SE A U S I N O T A D T T T I I E S S L A FT S H R E A D OA U T A H E D C N D I T H D E I S E WN W D TE T N N M EE EN I E H OM I M 7 TI NF L CI O VM 7 C I I P ES C EO 9 E , T M TUE R C 1 L Y AS O L R E EN I U C LC DR N SA R J LN C E I E ) A OI TH EF TE L C F EC D TI I B N D I L A E A R L EDC P E T G , CO L ZEE M A I S T ( I PP OR N TN Y ROS C O I SI FD R A L F G E G I N O : MEE F I VR D U T 0 MVD F N R NA OO C 8 U EA A O O I M MF A 9 SD M TI R 1 ST I
0 T 4 N Y RS
- OA R O A - - C M - - - NP o o o 0 lI ,
O 2
E E R
U D I
T L C
U S R 7 L S E T E 8 A A C S R 9 C I - U 1 I Y T L LL T N T C N I N C R L H I A A OB U E A G C S R L S / R B U N E N P ( C T M T I T E S N R S E C T D F SE ON - C A I L F KN l E C A L A NI S Y l D R I N A T AL N B 0 O LT O R S TE R S N F ON I T D ED I SE T C T LI C E F N M I E N EU N R O D A YM D P E EG OO L W BO D S Y R T CS E E I C A R R SW N G H A 0 RO U E RO D T 4 C N ET C DI EP E P - I I WS N V H S L O N AL
) O I T U E T W H I B D D PH C OR O6 O S N U E E E R 8 N K T I P U T RE L GD D 9 K R N N
L OM F - E N 1 O E SG I U F I E EP A S T W M TN LI T S T R VO E E N I L N E T OL LN G E N RE UR O R NE O BE N U N R O ED S U EL T A V L J A R I PO ED XM R eRD S N
O MG EN R I S
E FD O
E L HI N
H C
U C
T C
A E
E EN S
N I I S G D T P N R GL TO U T U N YN I D R O) E N A A I O A QF A TA WL S 4 T U C RT R D EO H I E S 5 N TS OS G N R C R) TH D U 0 I O P E K E E G6 N E S 0 LN R U C M MS P E7 ES S N - E O OQ A M U U R T7 MA O EP R F C B O M S N4 EW P SC U OS N C C I R I - E O N / T E I I E N O D R R P R OG C SK F R I F E NC GO P CE U TA OI M S O/ A H R R LU TC L K O G S S 0 TU T U O E N FC P AE I K 4 RN S S H D P L OE O TR D R - E( - ET ES L H R AU O A P l RR S
) TC P DN F W XN l A ON F 5 N F N EO 0 DE PO O8 EY D D , A A O I S E O 9 MR E ET T DT R D RS W1 P A P P C S , D EC C EE PT E - OD O OA N E D A P DD N I 3 LN L L R F O S I R T I R FE V8 E O E ET OI U VE / S O F M E9 VC V VN T C OT C N C A M R 1 EE E EO EC O R N R OE TO
( DS D DC S A F P I N C R SC U R /
F F K A E I A R CT R TO EN P SW - - - BI - - E - -
o o o O t l l! f lI
il\
- l d
3 E
D I
L S
FS .
ON C O N SI I TT NA K ,
8 A D RG 8 TN ON 8 9 L E YI 8 1 U M T 9 8 SM WL . 7 R D I4 1
E 8
9 1
E B
5 N -
M R FO A X -
U R E F OC ,I E R S J E V OE YCT C N B O K YSTO / O N O N LA TCI S , G I I T EM I I SS Y E T
) C , N SN RAT R C D T O S A D RAE I U E E N T PN EHVDS N S U E Y N A VC I N R N M B E A I ENA E N P
> I M M S NMU V I R .
T O S M DT U NI S N C N O EN LN ON D O O C TE : YA OS U E E O' C
(
C I
L I
T A
C I
R E
TRTN I UEEE CTC VC Z
I R
H T
D B Z L E C W CNEI A O N U I B S ,ijI TR M T U P N U C L OR RS M O A P LI S E N TP , U S R R G N LN N I S ,S S N G O R E BBO A T , N O O K F O V U I P N ,A OS T I C L FPT A YKS T C S A D X O O C G TDUNE A I B E I S SE N S EZE L R V U S E PSS I ON0VE T E S R LE T CN NEV N R M O S
I O O ER P H DR L
U .EI KHS T . C L A
S N
R F
T EA DS N
J
.S .S L N O D H E O .P . D . N I C B I
T D
E E
T TOH TT C
.M A .
F F
D U V C H F .R ,
J ,
L I A TSE O F F F O E O E R I TS O .O .O P S C T WRI S RRR RR S O E E N EV R PDPDP T L R R O FPE E L E C F XR B U V D S A E M S E E T S T O E E D S N A S 5T M - - - - - R O E W F P M F O M L A R O N T P C B - - - S o o 0 o O
lllill l' l l
1' j ; ! 4 ,
1 i! , i 1!;
O.
- 4 E
D I
E L T S A
U Q
N E R D 1 W E A 6 E C 1 I N E )
1 V O R S
- E C A E R R E C L S S
/ F A ) T N G F I S N E E A T T A C R T N N L I 2 U S E A P L N T L O P R 4 5, N T
N P E (
2 I E 0 W R S 7 E S D E R A ( N R N D U E A A C D W Y H M E E N T 3 F I I A O N S O F V M O 7 N I E L I O N S T R S L T 3 I O P S h M A U T I O E E K R L , A T H G D N I O A S N A F T O O D I 2 N S N R K A Y T E 7 E O R l i L E O D R M P O C N R E C E 3 M R W O E D U L O C
O C
N O T
'W U L
N G
S S
A , I N 1 E W S I I S C I I I . R I S T F K N S F 7 A N I E N M) M M C D A D O 3 O3 O) O I R T S I R R2 R F A T K T S F 7 F F I W L N N A N 5 R R E E A M O G3 G G A O E M T R I N N2 N L F T E -
O T I U I I C S R F F C TR TP T E I O N E LH LR L D R D U I S UT US U N A N Q Y S S ( S A U S E E R P E1 E E S O K R V O R R . RS R L E R N R F 3 7 E A G G A 6 U S SC S I N - T 4 S T F E3 EI E R A E - S O G GT G O H V N A F E N P NC N T C 0 O F U N A R A A A I B I A Q O HS HR H D P A S S T E I C( C P C E R N U S R S S E O I G I V L R T E L A C R - - - - A L A - - -
0 o o o O.
ll fi l Il
. N S H G E C I S R U S R U S E E T E E D T C S S H E U E N T T M R R O N A T U P N E R 3 S T S I S M A
. C E L P P 7 F' S U R N E I O I R O / U F 3 S T L I C Q O N Y S A T L E U G L D P N S R I A L O R S R O E H S N A M O S O I I T E A I S E F T R D D C Y B R A O E 1 N E C A T A I T T
- . R O P N S R R S C 7 O I S E Y -
T A I E F T S U G N C V H J 3 C F K Q R O E E N A ON E E P H E R P O R A R N D S G M R I E N T F E E -
U I W S T T G - S E O T E O N I L H C A S R F R M I SA G I S B N H E O EC I TE O T L A D E D I H S R ,
P P OF S
N N
U O
R U
T CR I E T
F O
A U L T E C N
G I
S E
R S
E I
I T
L Y
L N
O R C MV N U S T U O I G U S N I R E E N M T R I D O T D R I ,
A F T EN I F S U A D D D O S S U T O R T T E E N - O A I O C R T T E N l RR N S F U E C P M O l OG I TY R C E O M I 0 F - B N R S T N L D O T S E M U O E S U E A C A S V O O G U - S E C R E0 C ME L N R E R I O N B A T A I O Y R F F I A R A V F L E F I -
L O D C F M W 0 C S ED F E G O S O E E DN T F N E D S Y. P G I A A I O I N I N N R S N U I M P O D A O A -
A GS R I E M I U R I M E H E E L S A T T T M H C CP T N D A S E A U T I I I F O R S D S T FP R O P F E Y U N N N I C S O N T E I A CD E E E I O M C EE C C R N G V T M S I P I I N O I O E F S R F A N I T T N C G I U I WG S C I O E N N EB C OI I E S I R A G R E L S V R N T H I O S P L E E I E P F C S MA S A D R D S O O T
S O
o O o o o o o o o M O
F N O F O O Y T I N L ,N T O T .P G S E I I A S G R N C M S TI O .S I I E D O A R D M R D FR E P R E E N R I I D S BT T R EI O C U I I I I P O S C E Q V D L R E F I D D C P E O A C C VE N A S R R D C ,C E EC A P N T D A L R N D TL A R S E B E SE U A N O A MY A OR MS 0 R O N F P R L I TE A I l i E I O O E F F R V TN T D I D H F G I D E GE I E A E T E T R R T N R O R WG C T T C D I EA N E R I C C E I W P L A M E P E TA F A E J V U M R B N I P J E O S K S G O A G E S TM E R R L R N C N L MA S I R P E O O T ES I L E U F V WI O R D O I R E J R E O S E T N O GW I L O R I L L A L H N U B H J E S A D YS L T O 1 Q A G A W N S E N N L E I E 6 E T U M O I S O E L T WM S ,
R I O T S S N I M A I A 1 U N O A A A O TM R S F R H ES E N H E BP I O E F E . U T R S DC N E A H SG G T TD O E D E E H T T E . A O O N S N R A R G T S O R R VN N A N
O 0T I A
D N
E M E N M S I O G S 2 F C EN D D 9 O E C I R P E E .
R N D O R D C 1 E E S A EF WS U A G R E 1 ME E L P . N U L 6 R C1 N G C S G A S C 1 O X- N N . R N Y 1 F E 0 - I I YR E S C
- R 1 T L A D R E F N S E E N O 0 E C P O E O I B S A - Ti l B
/ S B I X O H T O G E N Y T E O L T S D G E E G O TD C T C E E N M F R N I L A E R UD I O U A D L U R C S F E L N TN N H E I O E A T O H A E S G RN C S BH T L C T VM E I E G A A S N P E N O M T S B I D BB I E F O G O E M S E O S R F I S N C U D U E T N R L E E N T D I E T N D S G P E R O G A O P R I N E I V U T EI N H M S I N R G S - E T G S I T A E - I O G E L C Y A E B E D R N E U D N U H S D MM E I C N S O E R P S O L W N O D CI S T O A C C - A E E I I R N S S P I C S R D T R ME O - O M L S I E I I C S TP L L E S A E TU U F U U I I S I I V I D D I L QN D Q C E R E S C R O H S P A E WS O
MM O R A C V E O R C E E R R o o o o o o o ll' '
T R
A P P R S
R F E C H E T L 0 B S 1 N h D A I T R R N 0 -
I O T O T S U C C I -
T S E E T N S R P I O I S S S I X D D O S E R E 8 P I O L 9 S V Y C A 0 I E D E C 0 D R A R S - A E R N E R 2 G G C O R X L
. N N / I I I A 5 I I G T U D
. S S E A Q N N 2 U U R R E E O S U E R P I N N ) ) N L P S O -
O L L E D A I I E I A A S C S L V T C T C C A C T U 0 O C I A I I A N O 0 R E T C T T H E W1 P S C I R R C D M A F E E U N M P R I V V S U O OSR P C O C
~
E & & N R W P O G C F E S L L I I O I A A T K L '
V N T T A A B S E O N N Z E U N T R I O O I P P A H T Z Z R C A G F O I I E O T I F M R R T T S R N L A O O C E OA H T D H H A D I F L
.G S N ( ( R E T P I U A L I A H T O A A H A L R D N R R R C C I T R E G TS T S T C A R C N C R D U E D R F EO E E A E .
P N U O P I P T R V ,T S A C S T S E T I TN T Y I M C E N E ES T H C D C A E C E V S C C I N I R P E VE N R E R F O F A S R E O O L A I C I P N P F D F R C C 0 S N G S E E EE E E 6 T GI E S W R I P T P L . N I S R E O H S I S P 1 E S E TL O - S - I M E D EI L T D E E T . M D VS A E TR T L G O E I D R I O I U . C A H TF E E R S F S M R T A O B S E T V I F O E R R D V E N N E E L E R I S B U R P - - - - EF N MO B E O U H O o o
'c OD C N S c
N O
D D S A S E E A K P T I R N U P C T O Z N O E N C ;
0 O NC E E " D N I C U P E I T H A Q S 0S H U T E N S F A S L I R R O E E D B O WE F I T P I aS B T I Y V , E S M T I S T O 1 Y R EU A S R .
D I N O L 0 P 7 ET R P R P L 6 .N N O R 0 E S A . S 3N E T E R W I 1 E EM S S S C O D R N P KM I S I T P O . I R O HE S U F G L S .C L A O E . E S E B T D R D O R C M 1 K A E I TD I I ,
E
. C U I R U L TTS 7 O Q F O G A F B N A
. R E I F O U 4 E C 3 D T D X P M -
T A S D EI S ME Y N A U E L D TG U R B O E J T I N R N MI -
I R T S P A E OI I U E
. T O A T T O TP F R N Q S C R N O D E P F U I E A E E T D E N A D A ED MR C 9 C S E M P
- A F
R N S O U M
M O
C S U E S S D I C '
F I O E OY S L F
H TR E B F S T O I U O O T TT R P H T N S O N D T G A E I T O TE N I MH S I N L E L R E I T E I M H E R E H A MA E G H I M R E T R I T U I E U R E I H I Q T M D I D U E E I U Q R E T R Q E E N L L O ER R O Y G E D A F R O H I T N L E A T D M S G T I I P V R N A E Y EI A S S I I T O I D TD I H C N T E C Z R E I E R O E N L C E I E E S E OO L D E U E P R TN N N TO H M R S O I E ST N L W H R S D D I O A E S E C I N H S I R . S T S 3 L A I T TT U N N / ET A E O C S E O 2 TU R E MM M EE O M P I P TL I U P R T M S = NN C B S TM L S E O E I I E A E I O T N C R L F P N N EN R R N O A E C S O I L I T E I I N C D I I L P M N W T G I M R TE I O O F P I T ES ES D TE P O O S R R I WE I L VI
)v C
~
(
E E D V O E
- M S : i O U U P Q G U
MF o o o _ o o o o
i ,
1!I!
_7
.o D E
D I S V D I 9 O E S R L A E P I B S D A E I S T E H L D E S C S O D A A H C OS T R D - R I E OE Y P S DM FD B PA N E D - A B O TC SA D E I EI I E S RE T L T SE T A ES I ES AR A C HA S DI BE N TC D O L W I N O -
E P 2A D M O Y T S E ET I - B A I &R DA L D -
%M O O T T HA RS N TC 0 I SF I 2 4 L E PE E M E
. E TE N M R MN 7 O AC SI E E O T S A NN R L R P E .
3 D R R A EE I ND D O T ED WD U E OE N E H C TI S I Q B W O T T E LU N U E NE I I E P S A G A G R L EI T MM S T L VV
- C I N I I E E L O E E W GR S W S M H T N M oR P S
T P F S P E O E S D D E O O C
C 6
8 F S O R I b -
O H T M L E 4 T L R B S S I U Y O U A S E T W S ECN OL P B U C R H O S E G N R E F S H A H I O U N T T L I F Q F O E F O H T O E O I M O G O R D Y T E I M T F N E R S O E D H N N - O V A E W S U O L E H I I S U T U L I O M G T E N S Q C T R E I A C O ES F i N C T R H R E I CD 4 O C I A N I E R T E O L R O U F N C N H NT G L -
E C Q O E S A NT ON N A T E G T R UE E I S N F R N N E M DM P - E I O O T E T 2 EI O D S G I C M N C TR L N OD E N N T E M I &I I E E O MO R O I A R O T CP V I H U I P N I C E 1 S I X N T YT T T O I D R I LE E A CE C C L B U SL O N NM
- U U E M F T EA SG E I E R D V O O C TE N T B U E T E N C U A R SU A M QL S R E N R N RT N O EB
- L O T RW EO I C RA l A I S EO WL M FT l D T - TL S I L P 0 O P l LL NN L A HE E D GC o S - - MO l A A A O 0 G I C S M HA o o o o o o
E C
D N E E D R U E L D F E C E E R N D R A I U L A
. 1 N S C 6 O I N S 1 I I A 1 T E
- I C S 6 R S N I 8 C O E -
/ P R E 4 G S E C :
E I F N E R D E E C U R R S N E A .
1 F T 3 D 6 E FN
_ N 1 R OE 1 I 7 A
. - 6 N C 3 6 R 8 OI C I F 8 -
N - / 4 S F O 4 G U U I S E E L S T E T R C C -
C C N U S N S E S E N A I I S A M M
P_ F O Q R S.
F O
Y G
C C
I O O L L B N S O U O T D P 1 I S H O 6 TI G H 0 CS I T 1 6 EY L E - 8 S L H M G - A G . E 4 EN I - .R MA H
CU E S -
S D TN C A C G S E E S -
I N T V F A EM I N I ,- O KA P P E E S F I N I R M C TS O LY P S E E I T D R R U L E E" D E I D U C C EH U S N S N N ,
I T Q T OE E EN R .
E N C R R R U N R E E E X BI M ,E F F I N M G H E E D I D G O N T R R N E I C I E "
YC S P T E EP S R N E I C D D P D OE D P E U U A O GR L L L H EE K D F C C I T TF N E E N N I E A E A I R I I I M C R T R h
U B - - -
o o o I
t-Q f STATUS OF THE CONTAINMENT PERFORMANCE IMPROVEMENT (CPI) PROGRAM PRESENTED TO ADVISORY COMMITTEE ON REACTOR SAFEGUARDS O JULY 13,1989 WILLIAM BECKNER, CHIEF i SEVERE ACCIDENT ISSUES BRANCH l O OFFICE OF NUCLEAR REGULATORY RESEARCH l
e l
BACKGROUND l
- THE CPI PROGRAM IS ONE ELEMENT OF THE' INTEGRATED APPROACH TO CLOSURE OF SEVERE ACCIDENT ISSUES INDIVIDUAL PLANT EXAMINATIONS (IPE)
- IMPROVED PLANT OPERATIONS
- SEVERE ACCIDENT RESEARCH PROGRAM
- EXTERNAL EVENTS ACCIDENT MANAGEMENT
- CONTAINMENT PERFORMANCE IMPROVEMENT O PROGRAM
- THE CPI PROGRAM IS BASED ON THE CONCLUSION THAT THERE MAY BE GENERIC SEVERE ACCIDENT CHALLENGES TO EACH CONTAINMENT TYPE THAT SHOULD BE ASSESSED TO DETERMINE WHETHER !
ADDITIONAL REGULATORY GUIDANCE OR REQUIREMENTS ARE WARRANTED.
- THE INTEGRATION PLAN ENVISIONS THAT THE CPI PROGRAM CAN BE COMPLETED BEFORE UTILITIES COMPLETE THEIR IPEs SO THAT THE RESULTS OF THE CPI PROGRAM CAN BE INTEGRATED INTO THE IPEs AND THE ACCIDENT MANAGEMENT PROGRAM.
O 1
, , BACKGROUND (CONT.)
- THE STAFF PRESENTED RECOMMENDATIONS TO THE COMMISSION CONCERNING MARK I CONTAINMENTS IN JANUARY 1989.
l BALANCED APPROACH INCLUDING ACCIDENT PREVENTION AND MITIGATION.
RECOMMENDATIONS INCLUDED:
- 2. IMPROVED DEPRESSURIZATION
- 3. ALTERNATE WATER TO VESSEL & SPRAYS
- 4. IMPROVED PROCEDURES AND TRAINING
- 5. ACCELERATED SBO RULE IMPLEMENTATION es
.m .
O* ACRS RECOMMENDED INCLUDING CONSIDERATION OF THESE IMPROVEMENTS AS PART OF THE IPE.
- COMMISSION APPROVED PROCEEDING WITH THE >
HARDENED VENT AS A PLANT-SPECIFIC BACKFIT AND ACCELERATING SBO RULE IMPLEMENTATION.
.. OTHER RECOMMENDATIONS TO BE INCLUDED AS PART OF THE IPE.
- CURRENT EFFORTS ARE DIRECTED TOWARD MARK '
II, MARK III, ICE CONDENSER AND DRY CONTAINMENTS. ,
- THE PURPOSE OF THIS MEETING IS TO PROVIDE THE ACRS WITH A REPORT ON STAFF ACTIVITIES IN THESE AREAS .AND PRELIMINARY CONCLUSIONS.
O 2 ,
d O . CPI PROGRAM STATUS AND-PLANS
- CURRENTLY PREPARING A STATUS REPORT TO THE l COMMISSION ON STAFF EFFORTS FOR MARK II, MARK III, ICE CONDENSER, AND DRY CONTAINMENTS.
- PLAN'TO HAVE A PUBLIC WORKSHOP IN '
SEPTEMBER TO PRESENT STAFF FINDINGS AND TO SOLICIT COMMENTS.
- CURRENT SCHEDULES CALL FOR STAFF RECOMMENDATIONS TO THE COMMISSION IN JANUARY 1990.
POTENTIAL PROBLEMS THAT MAY DELAY THIS O* EFFORr INCLUDE:
AVAILABILITY OF DETAILED NUREG-1150
. FINDINGS,
- SUPPORT FOR. LIMERICK HEARING, AND
- - IMPLEMENTATION OF MARK I IMPROVEMENTS.
O 3-- - -
, , INITIAL OVERALL CONCLUSIONS
- THE STAFF IS MAKING USE OF THE LATEST RESULTS FROM NUREG-1150, LASALLE PRA, OTHER PRAs AND RESEARCH BEING PERFORMED UNDER THE ACCIDENT MANAGEMENT PROGRAM TO IDENTIFY SIGNIFICANT CONTAINMENT CHALLENGES AND TO EVALUATE POTENTIAL IMPROVEMENTS.
- WHILE THE FOCUS IS ON CONTAINMENT IMPROVEMENTS, AS WITH THE MARK I PROGRAM, ;
INSIGHTS ARE ALSO BEING OBTAINED IN THE AREAS OF ACCIDENT PREVENTION AND ACCIDENT MANAGEMENT.
-
- INITIAL CONCLUSIONS ARE THAT MARK II AND ICE -
CONDENSER CONTAINMENTS ARE MORE O VULNERABLE TO EARLY CONTAINMENT FAILURE ,
THAN MARK III AND DRY CONTAINMENTS.
HOWEVER, THESE CONTAINMENTS' ARE LESS VULNERABLE THAN MARK I CONTAINMENT.
- VENTING WAS A MAJOR ISSUE UNDER THE MARK I 4
.- CPI PROGRAM. HOWEVER, THE ISSUES ASSOCIATED l WITH VENTING FOR OTHER CONTAINMENTS, PARTICULARLY THE MARK IIs, ARE DIFFERENT AND THE RECOMMENDATIONS MAY DIFFER.
O &...
, O. 1Nir14t ovERitt Conclusions (CoNr.)
'l
- RECOMMENDATIONS FOR OTHER CONTAINMENT TYPES WILL LIKELY BE MORE BROAD AND MAY INCLUDE:
SPECIFIC RECOMMENDATIONS FOR GENERIC IMPROVEMENTS, RECOMMENDATIONS FOR PLANT-SPECIFIC EVALUATION AS PART OF THE IPE, RECOMMENDATIONS FOR CONSIDERATION UNDER ACCIDENT MANAGEMENT, AND '
- RECOMMENDATIONS FOR ADDITIONAL RESEARCH. !
- .. j O* THE APPROACH SHOULD BE CONSISTENT WITH ACRS VIEWS EXPRESSED IN COMMENTS ON THE "
MARK I RECOMMENDATIONS.
O -
5 --
'I
- -__-mm-.__..-__ _ _ _ _ _ _ _ . . _ _
1 1
l l
1 l
)
1 e
V (
v.
t
- =-- 26 ,
% .; 3 - . y a:::. em !j s au--.' y:
- , . i .
.h i - - - , : . %e ] um f - " # *E lb - =n' em u< 4 - ,. r , ff :-,.nr f < = .l nq % l TP ;; / e._r - Pbp '"3 '. i ' g I !. .., '. N e hl ...~m .. g-_ - Ew.5 +i mz $'l}t m.,, f - yI '.-s _. _ ~'l = = f ."g = [_._ _ _~r"~7 : = "--" t _ .a - 1 ~ h, l l I 1 II &L. l % < hN. , l ' lt*.2 . M $_M L . , Y =m. i . e. o I a =s M P. i? . . . , p.:.::suus,s h*% 7 f j f' si I @ Y i ga , } me ] um l g $. p - - - mar - -- - ..% m,f m q --e p, ,l ~,.i - % I A .,"4 " = p i JJ s.. _ . .p_7 F "- i m Y S - 3 9 l l _::. 5g La-tz 5 ,; - m . FN husggw.r.l"44 a M tie,,{gfjjgE -M f Qv&(.,kEll 2 N I D. .+- D aex.- - e.- aty - SEC7 ION A-A w O Fi gure 1 Mark 11 Containment L_ _ _ . _ _ _ _ _ - _ . _ _ . _ _ ) k_ . CONTAINMENT STRUCTURE O O e O O 0 CONTAINMENT ^ 0 0 SPRAYS O O > e e *
- HYOROGEN o IGNITER (90)
O O e e , , e * . POLAR CRANE 'a. e 6.*.'*.s*'..'*. *;*. . ** E. * . , ?l , e . I . . ea \ / - t * *' REACTOR , SHIELO. ., '* - - r / WALL
- =
'. e .,
- . e ..
JENT - *.- . . . t WEIR ' ~U ~ ANNULUS ~ - WALL t,' , C j $ V
- ., ,1
[ , j,-- t ; '* \ :*
- . m
/ VENTS HORIZONTAL e- * . m ..',' - -r . . . s. SUPPRESSION g , 2l * **
- (
--- -- ~ . ; .* REACTOR . POOL y' w c .' CAVITY ', l =
- E . '. . . . .. . J. +'. ....,..- E '.<, CONTAINM E NT
,'e -v . . . ' . * 'e .* . .*..'." m ._ / B ASE M AT
- . ;r. .,. . . = . . , < . . * * . *. _. .'
e..;,......;;. e , , . ... ; ..- ;.y
- ..,? .. , *.e.. . . . ,
- a. ..e,-.
. . . . o .? . Figure 3 - Mark Ill Containment (River Bend has neither Containment Sprays nor Vacuum Breakers) 1 I gs . ,V. Comparison of CMF for BWRs Peach Bottom
- Limerick ** Grand Gulf ***
SBO 2.2 E-6 6.7 E-6 3.9 E-6 j ATWS 1.9 E-6 1.1 E-6 1.1 E-7 TW Neg. 5.5 E-7 Neg. Transients 1.4 E-7 5.4 E-6 Neg. - LOCA 2.6 E-7 Neg. Neg. - O Total Internal Event CMF 4.5 E-6 1.5 E-5 "4.0 E-6
- Second Draft NUREG-1150, June 1989.
- Limerick PRA - Latest Unreviewed Results May Be 50-60%
Lower Than That Shown. '
- Second Draft NUREG-1150, June 1989.
n LJ g Table 1. - Comparison of BWR Mark 11 Containment Design Characteristics Plant -SusQuehanna Nine Mlle Parameter . Limertek 1.2 1,2 La Salle 1.2 Point 2 Shoreham WNP 2 [ Cea*a += cat Des ign ' $36,759 526,880 650,100 406,812 457,727 o total Volume 520.294 3 x [f1 ) . o ' Wetsell Volume 289,100 281.500 297.000 346,800 215,400 256,400 3 ' (f1 ]
- o. Containment 163 158 160 197 167 139 Volume /Themal Power rating 3
(ft/HWt) o Wetwell Volume / ~87.79 85.48 90.19 105.09 88,42 77.86 Thermal Power e rating 3 [ft/HWt) O (,r o In pedestal Same 1 in, below Below Below Same Be lo-Floor Relattve to Drywell .. . Floor o - Drywell/Wstwell Downcomers - Total Area 2 363 242 309 (ft] 257 242 295 87 82 82 121 88 102 , , - No. Ex-ped. Height above 18 18 18 3-6 6' ? floor (in) ' No. In ped. 0 0 8 4 0 = 0 -- Height above n/a n/a n/a ? D.5 n/a , floor (in.) o Design Pressure [Csig) 45 48 45 - Internal 15 53 45 - Esterna) -5 -5 -5 -5 -5 -2 o Drywell floor Design pressure (psid) l Downward 30 28 25 25 30 I - 10 ? 5 10 10 Doward o Mastmum Leakage 0.5 0.5 0.5 1.1 0.5 (tvol/ Day) .O ' O " l Table 1 - Comparison of BWR Mark 11 Containment Design Characteristics - Continued Plant Susquehanna Nine Mlle Parameter Limerick 1.2 1.2 La Salle 1.2 Point 2 Shoreham WNP 2 Coatetamcat Desien o R HR HX ' 8 - - Removal Rate 122
- 2 134
- 2 156
- 2 95
- 2 89
- 2
[MSTU/hr) % of Core 2.2 2.4 2.7 1.7 2.1 Thermal Power DBA teaf n escense o Drywell [psig) 46. 44 - 4D. 46. c Wet ell [psig) 34. 29. 31. 34 34. , c Dry-ell floor 23. 22. 24, 17. 23. ,, . load [psid) Combustible Gas Ceateel o Prsmary 4% 4% 4% 4% .. 4% Containment Dy [1] o H gCombiner 132.
- 2 7*2 135.
- 2 150.
- 2- 60.
- 2 flow [sefm) (Bothuntts) .
Des tem Temocrature o Drywell [*F) '- 340 340 340 340 340 340 - c'Wetwell [*F) 220 220 175 212 225 225 l
0 --__-_ _-__ _-___-_________ -_- ____ _ ! l13i. ,l' =- 3,} . 1 . 5 ; m ,. . N. . 2
- .'. .2
_ ?b . . . -j..,h.,....i.....:.. 2 / / 1 1 n o c\ ~ _ - - - e: ' a i n D +,y ;::. .g. kc .* i a n n t a r r h u - . . .,.. e e g Y I-w. .~ i m uq i f N .. L s n . ,~ c]: n: . :...- 2. , .... u o m/.: .?; . , .i k.... . ... S c b _. i,;- .- . 'm o l N . a % p t s les a l , ic= t e" . e d M'"% gt . leke . e e eel Ss h o C '* m6 . I p s7- [, . .,. : . ;.> . N :
- u, I
k r - . ..: . ea 2 a F_T*... ... . . : . . :: ; 5., . . . . : x- ~ ai :. M c.-_ / ~ sT ., .. . 1 .. e
- 2 e h
. . .. ; - - l t . * . '. . e .. ;. P l ? .:. ,c. .f..*.. N a n ... WS i w i./ . .. :i. . P ,.[.l - . . ... . , ... : ,.l:. L a i s n o T. - f .. - t I : a i = s r e a t e s s e v r t e c r
- loo es Df r
w V 2 [D. a te I x:. . e r .* ,,.t, . . - . (i . .,.. ..,~..:...- .. 2 u
- v.< e n g
\ t - e..: . . . : .%:^ i .. i
- . ... - F 4l /
p- ..g. e m a o h P e r i e _ o _ .-. .i,. . l \ h i At 1l ir . S M .. :..= u . _ . .. .:.. .. . . - 1.! .
- e _
n ) h . i N
- .' i,,
l- 1l1i, .! !'1 11 ,i i 0 - BWR Potential Containment Challenges Mark II . Mark III Over-Pressure Early Pool Bypass Hydrogen Detonation Late Pool Bypass Pool Bypass or Wetwell Failure Over-Temperature Drywell Head None Seals (Reactor Building Bypass and Direct Pool Bypass) Likely-Timing Unknown Pool Bypass c Highly C Uncertain; Before Vessel ,. Breach to Many Days After Vessel Breach Wetwell Failure Excessive None Water in Wetwell Drywell Failure Steam Steam Explosion Explsion (Shoreham & NMP2 only) O 12
- e
\ . BWR Potential Improvements i Mark II Mark III i j Enhanced Reactor Yes Yes Depressurization Capability Additional Low Yes Yes l Pressure Water System Utilization of RWCU Yes Yes for Shutdown Heat-Removal (Supp. Pool Cooling System) Containment Sprays Yes Uncertain Venting - Hardening Uncertain " Uncertain Pipe - Pre-emptive venting Uncertain Uncertain - Drywell . Head Seal Uncertain Uncertain brywell Head Uncertain N/A Flooding (Except for River Bend) Hydrogen Ignitor N/A Uncertain Backup Power O 13 ll BWR Poten.tial Benefits of Improvements Mark II
- Eliminates Potential DCH
- Minimizes Pool Bypass (Early) by Vacuum Breaker Failure
- Prevents Wetwell Structural Failure (RWCU System)
Reduces CMF Due to SBO and TQUX .
- Maintains Pressure Below Ultimate Containment Pressure - Possibly Below EPGs Venting Pressure O
Mark III
- Reduces CMF Due to SBO
- Eliminates Potential DCH O 14
O Unresolved BWR Containment Challenge Issues Fuel-Coolant - Probability Interactions: Forces Generated Required Pre-event Conditions Corium Spreading: Minimum Depth for CCI Conditions to Initiate and Sustain Spreading Rate of Spread Effect of Spreading on Crusting Effects of Solids in the Corium Effects of Water - Retarding Spread - Cooling Corium -DF Timing of Poc! Bypass (Mark II's Only) l I O 15--- - _ - ~ . . . .- m-ICE CONDENSER CONTAINMENT (SEQUOYAH) SHIELD BUILDING DOME CONTAINMENT SPRAY
- s I
STEEL \ o 0 0 'k ,[ HYDROGEN ,', CONT AINM ENT - s#1GNITER (64) VESSEL SHIELD * , e * BUILDING WALL \ . AfR RETURN F AN (21 g'".g , . a ! 0 0 -*' TOPOF ? O O DIVIDER l [ l 'I W ' BARRIER . , , ;,,,, ICE DEDN~7~
- f
,y = Q . , = . a CRANE - [p STE AM jO ICE / WALL *
- . .A GENER ATO R
\.sDNDENSE RN N t CONTROL , , ROD DRIVE , MISSILE SHIELD '?r * ., t~ E . ) j 3 PIi . _. . . . _ . . . . . f,, .,i _4 LL L , VAPOR ' ACCUMULATOR ,' ,, -- 4 '.y VENTILATION FAN N s . [ ] , I'.M.
- AND EQUIPMENT ,
4 g,, * , 7): - ( ,, 9 p , s ey - w w a-1 y * .' ' . 4 * \ ,; 's , . . ..- . _y , ;g t ,' . 3 u ... , -%*' . ... .*/: * .,. ,, p,.' , ,*.*,*;:f..;
- L'
- .L;;* . .
- ' ' ./ . ., [
. f..**...,':.*.... .. . 7 REACTOR } r/' . *. ' STEEL LINER . REACTOR'j ' ' . ' # ' l*' ' '^ . ' k,
- CAVITY t* '*- * .#*\-
\ SUMP O _. ._- figure A.5 Schematic of the containment design for the Sequoyah plant. I N A-9 4 . ' . . 6 " . . k'. ~ r e 2, d 1 n i S e r 5 1 2 l e e s e l c y T iu 0 t s y N l G e c e M E t s M 2, r e N I 1 l d i n a e A b 5 2 2 e s e l y T t a w 1 1 0 t s y c N C a l e e O t s C 2 r e 1 d R r l f l n E B a 5 5 e e s e y c S t s 3 1 0 t s y l e N t a t e h E W s D l r N 2 d e n O 1 O h 8 2 5 l e s i l C a y o 0 1 1 0 t s e e y y c - u q l e E S e t e '- C I s h e F t r e it w O c n r e 2 o d c n N 1 k 2 1 5 2 d e o n ir l e yn O o o 0 r c o ci l , S I C f n e tl ee re R ie r ct ns A o c P M ) ) y n O i g s ) d a / i o r y C ( p 3 t f 1 e t c u a d nt e m r on s r u ce N u s 5 0 1 l o t s n em S n t n e GI s e r ( e ( v C o ea t t i o m m P m e f en C S n u t a o ro cC E i g lo V R e p n o D D s e k a e T y C L O i; 5.- Sequoyah P12nt Results in- .M. f) . LOCA "
- g!!"
Tii!!ji:; - ,, A , dij; / 3 4 f - iih O [F l = !!!!!!!!!!! iii! i " 'i !!IN!!!ill a . .= i i / Translent !!!!!!!"j!!!" / \ !!!!!i l 7 Bypass
- (int. Sys. LOCA/SGTR)
^ Station Blackout Total Mean Core Damage Frequency: 6.7 E-5 O d Figure 5.2 Contributors to mean core damage frequency from internal events at Se guoyah. NUREG-1150 5-4 _b____________----_________---_--_______-------_--__.---------------------.-------------------------------=------- . O. ! FAILURE MODES IN ICE CONDENSER l CONTAINMENTS AND RELATED ) l RISK SIGNIFICANCE RELATIVE CONDITIONAL FAILURE PROBABILITY (given core melt) RISK FAILURE MODE EARLY LATE Direct Containment low low low Heating - Hydrogen Combustion .- -Early high high high O -Late high ---- high Containment Bypass high 'high high -Stream Gen. Tube Rupture -Transient Initiated -Induced -Interfacing Systems LOCA Nailure to Isolate low low low Basemat melt-through medium low low O 19 POTENTIAL ICE CONDENSER CONTAINMENT IMPROVEMENTS CONTAINMENT CHALLENGE POTENTIAL FIX Direct Containment Heating RPV Depressurization Hydrogen Combustion Back.up Power to Igniters Additional Igniters Containment Bypass SGTR Improved Inspection ..- Techniques - O Interfacing Systems IPE Resolution / Proposed LOCA - INEL ISLOCA Program Small Break LOCA/RWST Depletion i RWST Refill /Recirc Fan .. Initiation Set. Point l 2 Dominant Contributor to LOCA Core Damage I'requency. f Not Significant Contributor to Containment Failure. t O 20 7P i LARGE DRY CONTAINMENT (ZION) ' f.. ; . - CONTAINMENT ' *> *
- N '
.***7,5 SPRAYS I.*, y. ... . p' e .,t '.,,: e "; t e ? '. / e
- ] .
i 1 POLAR CRANE .) ~
- i. r' % r
?. b - .e . STEAM - , GENERATORS ', /N ) G . i
- c
} n A \1 7 1E ~ .y r;.j d.] E - 3 'g*, ,g p, t
- i
_ i,. ( .
- . :; - ; / \ f: - .i t
~% .. l. ~ ' ^ ,( f v :. 2 s U -~;! 4., . i, < Y*: h* . c'. ; . ? y . .m N . .?.,,.z ,. ..D ...,.,m - u T.ns .e ..?.'6 n . . :., ., i s't..,..*,'..e..,
- .'; .]'.
,.,.,;;.:,_ e.;, . . , .r.. .,.:.
- . . :...e.....=:
;i.::.. . ::'" ..e ,/ , , *,;,**', REACTOR VESSEL IN. CORE . INSTRUMENT TUNNEL *k.# *.;
- ';*.,T
',.*'),'*.,'** t . .*h REACTOR C AVITY 9 FT'BASEMAT Figure A.3 Schematic of the containment design for the Zion plant. O o\ A-6 N I i - SUBATMOSPHERIC CONTAINMENT (SURRY) 3 i er o4 o4 CONTAINMENT SPRAYS 1 l 1 e i ! ) ' 200 TON CRANE , ,e I 8 b MECIRC. SPRAY 8 ',- .e s .,, , , g
- MANIPULATOR <
STEAM CRANE GENERATOR h PRESSURIZER g . , _. .' t r. (~ - I k \ y ,, , ,' Q *'*- M ;, L.- *. .& ..,. . r-
- . ', ' s e-
- C ,', o' ( < {e .. ,* l O. i ,. ': l u - l'l [. . ( '. .b, i [lN h . - e,. REACTOR ' R. C. [* e' D .. *? PUMP l= 'e . . . . . . . . - . ., t, i.~.
- .' ?. ','
ACCUMULATOR ?- .. REACTOR . N/ ". CAVITY
- e e.
, . p. m 5 g , e . . '
- s p, . r_ . a *2 ,-.-i,g
..*e. ,',A
- .e . . . . . r .,. .
- ,, .,e, .
- .e *
,e .,. ** ** *.*,,e , e,
- e '.
- e ' ' ,.s , '. ..* ,*
e.' e,'...,.,e. e '. . e * * , ,. . : *** . , ,s . , *, . . . > . **.n '.. ' ' e ,, . . . . . *, . . ~ , . , , . . . ' .e.. * . l Figure A.4 Schematic of the containment design for the Surry plant. 4 L - A-7 ..- q/ 4 -k ' ' ' - ----- ------ -- --- - . l
- 7. Zion Pjant Results
. O. CCW-induced Seal ! OCA Bypass AT WS Transients , Station Blackout - 4':' LOCA O e W ,;ui ,
- r!!
= it..;;
- ,.es ig :
,,, , w ;_, i t [h .{ h I F J,. ,. '.s., l SW-Induced Seal LOCA Total Mean Core Dam 3ge Frequency: 3.4 E-4 O i Figure 7.1 Contributors to mean core damage frequency from internal events at Zion. S NOMEG-2150 7-4 ' 3. Surry Plant Results .f~T .V. J
- 1. -
1 ~' Station Blackout !W i i u! i, > L L! \ ! f f' LOCA d % ATWS Bypass (int $ys. LOCA/SGTR) Transients Total Mean Core Damage Frequency: 4.0E-6 Figure 3.2 Contributors to mean core damage frequency from internal events. 99 34 NUREG-1150 . _ _ _ _ _ . - . _ - _-.____._t:____ .O. Dry Containment Challenge Likelihoods' l Large- Dry Subatmospheric Early Failure DCH Low2 tow2 Steam Explosion Low Low Hydrogen Combustion Low Medium Steam Spike Low Low Late Failure Overpressure High High Basemat Meltthrough Low Low Bypass SGTR Low Medium ISLOCA Low Low O ' Highest likelihood is no containment failure 2 Because of vessel depressurization prior to lower head failure O i i 25 I ,O.- Dry Containment Potential Improvements L Improvement Benefit RCS Depressurization- Preclude DCH i Cavity' Flooding Cool'Corium or Mitigate F. P. Release . Hydrogen Control Preciude Hydrogen Detonation Interfacing Systems LOCA Program Reduce ISLOCA - Likelihood Venting Unce'rtain 0 26 u ,OL - COORDINATION WITH OTHER RES ACTIVITIES ASSOCIATED RES CONTAINMENT FIX , ACTIVITY DEPRESSURIZATION ACCIDENT MANAGEMENT BYPASS --SGTR GENERIC ISSUE A-3,4,5: REG. GUIDE 1.83, 1.121 --INTERFACING SYSTEMS GI-105, IPE O LOCA RWST REFILL ACCIDENT MANAGEMENT l l l O 27--- - -- 1 4 i u_- _ l j il1l ) I ) . o . n u WE E E R ODR SFL . HI US H S O FI N S V SS EO OSE C N RFD0 OREN A H L E 1 T PRK PC OS G OHEDA ME HO I R L P A S U O SSE C TGH NT NN A DI I P R R T R A R I O E TR E A E C E B P SK R AC R D AO P E RF A P Y TS E PEE AL U TH E UWAR R A N PO R E U B O MES H L 9 C T PYBC S R Y L. T L 8 A R D RTL. LS A G ATT T F S A9 F N AF L E L R F AL L E O D1 A H AR I ME E V N R C 50WP I NW 0 U H T , OM - S EA5 A3 F F UN L 4 oEGSR R O N O R 1 E O T L T A.H S TR G I DFF EL SE TT O R T . N cHTE N Y UH4 I E E DI T F P C T T D L M SEK S / 5. S OP A E A T P J U U UF W2 TA O MR 1 3E 3H U R C OO A EE Y N OS H L P A C E DTNSF E M PF MN GWN S UO ROI0 SEI O OS ? O I O F OI E S L L R S I M TTYE F EYF 9 O P AE A LYI T V A T HT NO B R EGI K I L S TIL DEO I OT UR REAIBC TBGT C R C E EONTH QR R AAN HTA 5 _ H A RCEST N TSR6 _ C - - 9 7 6 7 9 9 O 1 1 s i' Y , T E NO E D F AT E T D L AF E E U T Y ES ON C N G D O I I U B V MI N L S EY NA L S W TD I MGK CS OS S T T OA RR NEL ESSE S E URE S C O I NR EN E PS B M W I RH HOE I N UI LA U UY D E U AGQ OUG T RR P STE H E D T , VAER TOD R E F T N NRY - TEL O DA E EET E ) N BAF OS OT S "E t n ESI I G C M MWEF O D o KL AACEI RRSN VH E . A E O AH O C PT EDN SI RL ST C I ( TI R R STS R O AU T F O E E EAY A & NI T E T DML E B SG 0EQHA OTMS SI A Y , o G O D N A 4 EN U M4HAE AT EE SU 5 R T STA MR S L. R BN NNEE L . O 7 T L 0 L S D A AV F I N S A E - SI CI T A D SE C L.TORAT WGL H O R SG A TC WSE SU E AA 0 F H AV HOW W F E R S AD I H TT A 1 0 S M. U O 1 VUE L T L G 5E C 1 P E , Q R NV L , I F . EG C B DI A O .UI RCB E X .N " EX K T EC TS A K XIF D S N MO I S C U TS E DIC LUD E UD RI AE A SRAL N AO L P I TN S T RI J E U I TBU N E PE O VCE C COO R ERR P P S COAP RRP 2 N SPG A AIT PF A 8 - 0 2 3 8 8 8 9 9 9 O 1 1
- f 1
1 R V M L I A N T ). N I A R R N OT O E TI I TN DE TU AE DE D E R NS AO 6 UT SI UU MBO A L AU L J AA BQEP Y( V D EL E E FT S A,RBA N ONE I W S R ", T G A O I I NA T U L LP ) ESSS O RA FO t TN E I TE V R RGBE D I n I GP o - AC a C CR P LN W D ( N AD UU A M ULX C E TN Y O L OG AA G T TO1 A TR I O O ANH1 C A SA I L UES DL ER O L L X RE VE N A AW EL O V I TT O VVA I L 2 S OA T AR I R H EU F F S TN T N C C WET Q OER YA SDI O EO . S E E T A" 4E T R T V L E TA FG /RS RDT I N 1 U SL V ESL O P EA GI O TP R ETN WIDASE A M T MR A RCR VTRR N E E E OAPE O RX OT C RBL JT HRH H T PTAT CFE NOA 5 8 9 8 8 8 9 9 9 1 1 O 1 i > 7 } 4 :. _ 7%
- - , s -
F II 4 d p .O- O\ 154 .ee L n
- a. m
.R . ^Q e - ^s g D % v ts '., s m g v Q J Ch i o 4. Y4 4 us ~ W A t 4 W L \ w Ys. 4 .i ~E
- 4. 1 s s
W s % .\ D g s 4 l; O ;w/ q/ u! < f l i l 2-__________--_-_- -- _. - a ll' . o A O 1 R M D N D ) UL E I P OA D L P Y T BIRN P R EA A . E T A N.E - .E D HP OP 5 W MI 1 E 2 I O D 1 O - L L E A 3 LJ0S >0S E AF 1 I R L 1 N E D ( = MO ORR A0 RO I F T E I S o G I S O R E = F I R O P SEU aC T aO E E - E C OP M M 5 OL A E A AT M A A 2 WATH M - TIT A F R S S TVAT J AD S L P 1 E E H S S P ) C I I L P T H R L Y S T D E E T.. I W E E R , C Y Y O I I P M R E L TI TR ) N oP T ) E H P A P U- S / P Y C A" LILG I B X Y T T P A F T I S t RL BI AS AP W. E E I J N AA W 0 2 0 , ' V V 0 S I O 4 7 / 0 0 0 HR CE I TS SOFL P O O 5 E R >4 L 1 1 5 P A 2 B B 7 3 1 - ( 5 " T W E A 2 L L0 F B N 1 C E A AEL E N A A A0 E VM I C 0 S S = R I O W l O X I P ( = R E LH FTCT NE 1 T A A ( G R E = T S U D EE N T t D CH UR 1 9E E P TV T a WH DEF I D 4 H P T AA O'FA N / C OIT 'P_ M M NR M- T R - F HWFE OA 1 I U S R O E 2 _ A - I 1 J O S" OR CS S 1 JC JA R D C T 2 A S S P S G S G E E I M I S R S R P T P Y O T S T C S E E N E E LY Z L R LR O E Z L R A TR A I A U AE I L I A U I S I P R B S I RE R M S R O E A M S E R S E W R S EP T W E E T R T TO A P I R A E E I A R I R A H R AR R L H L F T P M C V F T P MP C o ll ll1 l l l i i i ! l ._,..s .. l ,- l < ! I f { l 3 v ' i ! i
- 1 9.QD j
J-ygzy.puval.1sks . - l.
- i. i.. . Ikde 40;Wr/ds.=,- ;
, mo - ; i 1i - _,,r- - s .
- JQ . Ugru NUJC . .
l . ....l/k by.A, t 3 ) i .$.X. ; t i 1 l l -y , , , ., Men't? '~' O i w . .. . _ . . . . s ,. i o - g % r_.k[_stfzu m, _al M ;_Aff.a- -_ _ . . .g . i i N.4 m .- -.g-.-f - f , ,= s iz__pI.;o.r ,, , g j;.-.. T : r __ _ ', ."-- , '*~' g g. I l .q ._ .._ ._ .. , ./.'T ". . . . . _ . _. _ . - . i g j . . . l t'.. g _.y _ .__
- s. . ~
- r.: ,._._ r - - _ . ..p t::.. __
i . qgg . . . . ._ - . . . .. ;- -. ._g..._,.,.,,. 1.m . x .. p _qv V _ _ .. .______ . .y . _ g . . ;. . ._ q ;
- ,s . . . . . .... . . ; . _. 1
- 6 Jon u - i n r --- p r i _. I L9 -s . . . . L. . _ _ _ __ . _ _ . . e,; , ..+ _ _ _ . . _ . _ _ . _ . . ke e . ._ . _ _ _ _ _ _ . . . .t__ . . _ .. [. d .i.... _ . . . . . , . _ . __ C' EDO / -l ' ')V ~~ 6 \ . . . '.. .: _'~.'. a; , 4 g . . , .. . _ _ ._. - _ . _ . . . .. g -, p:, OJ . 1
- 1. .._. ..
. p gg ,
- . -_ _ --.}... .
i. 1 -~. . ._ _ _ . . . i i { 100 , /0 E!O 30 4d ' S 9 ! 60 70 I Cha' rpy-_Ubf_, AL/4 - .. t ! A i 1 _ W s# ye T _ ' . + ,qsfMLOO# " EY ## 4 - ,'\ x w A o ~) + / // 'N g/ s,\ ' , i O *; \ l ,N O Y I 2 G T 6 R A E E R E 0 N S R Y 5 E S U T Y EO-P E BR H N S F WT O O S D F A E DC O E S L O I R TE DT E P T AC0 O T A F P U 1 5 TD U R G I L C D E E E NE N ) I TR L E T I I TI G L BIC T DI T A AS N A M.U R I R L N S R H P T T oON CO E P T 0 F R S OCW.C A P E S E A T E O) S 0 R M C T5 Y ST S R G N 2 A U E TI CT D AS E SR OC P I Y NUF A L E SE F I S L EOO S R N NL UH WDL I 0 L G L N E G5 AA QTN E N E R N E I 0 O NE R 2 A2 TI M R WIOT SI SR 8W I M F E A T G Y TO SA VE E L A E L N DTT T D ACI C - T L E (N EN N R N XH I AA U TE E OE L
- I G L AT F UN QS CIS M TI E E E CT N I I I
T QM E RV DN L ACV I S O F L E AP E U A U D A (N N A I V R P R TIM R DH J O o o o'o
- l o
i I i1 c . Q i! . t W s L E I d r E V a u S R g S E e h S f a E V cE n S V O a R r , r _ B g o F n t c L M d gi n r t o a 9 8 E A l e i r e e d R e 9 H R 1 ie f n e o S G O M y ei g a n n i gE t n e n o 3 1 n s e R R e - .E f r e ly M o t u E P s P t i J P n a n l r o n P H i r i r e s o U C i t ai v C R MD y WA E r o s O i L S d v E A R ~ O _ W E I V G R . E p p ~ V A : O t i , y g l r e M nn A i t oe - y p ce w G r R a - h S lo G p p isC i s O r s ) s eo A lyif J ly R d , a a P ole l i l n n8 n Ct it i o Ai( a o6 r nt t H' E b oar e r a r bm M i t u ept o r l C S ts A n ct e c t f f R s iS e c o r a r y 50 ep i s A &g a ly r sR e p F f E I a aK i G a e s wt o t p n S . n A s 1 < iu l t j lo d E p o . c e pi e e i6 s u ob . e R A cet u t r r y ul ;K t i Dt d t aw s e ,t e 0 o ca c n aAlo+ yd l S 5 r r f g e r f l a n U pf r F Mt r i F 4m R e u M L F er e i n q E F l eE/K E eS P C ut s c i l t L 1 it 2 w R U E 0 s u r o 1 ad B - - - L - - o o o ' ((f l l 1! ! , A h a - .. - I s l W a E i r e I V t R a E M V O S U M L s A r e v R r G o u f C O c - R s lK P n r d e n H c a C n R R I o K y A C r o n s nt oiia i s e E l i f o sibt r i t S l i t y a a te s re e a l l E a gi aitt i i s r a p ni n n ct o R c n d i s a ra i s aii nd P e r s r ww o i n sh r i n S ly c ly f o o loi sl o h a et o a l t i ai t U c n p n s f f a u ly sir a L Ai s ed e A a e laat i vnaa . . l T M Sd h u M Ba E AMV F F E P L - E - - - - - o o ,{j 7jli' 1 ' e- s e l n s T a o _ i s ci y e St a P lo24t la n ed 1 A- P i gl ra A EEe B TTi SS d _ aV VPPW d L W oo oo t e E I a d V . i l R a v E i t . r n e V l s e n i mio t ly l O l ai Ro l u it rr - ive y o f P J t rst p ee laui i o M t a o p 1 oeCsdr t r lyi t la e. A Mr vorRan ve cs P CCJ A- - ue - R o -o ds oy G rl p a $R P 1 n . oa P d t S a M H 8 r gt yEF e r mU L e rl c iL i a C r r C .'8 P uaitd s g R IY sms e r lat e s o 1 r c V, of r A A " PhtePeM erF r h, ps E I sh sop e vt ucE S Jw - i ~ hr cu E rd R ae ec so S s . h Rp er U n ,n eh th -Rg t L oe S e8t ,O J e n ig 1 r t nrd R S P t aa im d 1 i o3&IK t aa iad h c, & rD r dnt iv - t a29KC r I r - - - l = e Or l W E I H V C R R E A 9 V E O S E M R A E R G G O A o R P M A . D H C N R O A I T E A S I E D R A R S R I U L D p 1l Il l , 1 ' l! i ; I {j1 ' _ . O t g
- )
4 S 0 f t a . C , s s N o n NI .O ' os t N OT I I A O TSE AOC I PN D ME A R O LU R C F I NN D NOO OP E T R A N RU T I i DL T O / AE LI USE U ? /, RET AA T ED N RS MR RE ~ E NN OP R ED NO U T O TP S EN A R FADA , - E P UM Y EE DL EE E B GR T TE NU AT I S DA T D A EH C ~ R HCR U R I S N - I FT U -
- NOS I
O ME R D 8 I 1 DU C I m ST M I I c K' eN K A iG M O i\ I T E5)T,s C m B 0 0 0 0 0 0 0 0 g A O i 0 8 0 6 0 4 0 2 P _ ^ M I 0
- + ,
% 0 i ^ y 0 W 1 2 o A . 0 5 O 3 e +* g H D +* S E y A 4 H H S 7 S
- S 6
- A S A 0 6 i
'^ , - - 0 N E 1 0
- ee i
0 R . 4 E d v g oO M NC E o 0 A + CIO I 'e . T D O A E c # v*+ A 0 r o q^o O P Ai I J 2 i 1 1 v' g ve A 0 0 S D - - O e- A HH 3 4 3 T A% t 66 y g0 ^o y* - - CR 2 6 I c
- v *go Y=
n+ T 4 R I D I S G v 4 ) o 6 o v, y A A a0 0 % 0 F E 0 i M_ 2 0 # R S . v A 2 0 E v gg O OA E P C E R 7 % F R 0 A v 0 HH S C M0 I 0 2 SD L E OT v 6 b d l 2 G6 E E ! B R V - - D 0 MI Y D v 3 A v 0 V 4 i S_ SR R v v A V 0 1 R g . DR EI v U v L L / C- a I F T i R i - - l 0 0 L 0 0 0 L U 0 6 0 2 m e U 2 1 1 E$d, F O o 2 4 2 5 1 N S LD ND LDY Z Y-8 8 OR S D E D E D TI O E LE AT O TE AT LE I G W U T T T I DE D D D L AV T A E L E L E L I TL A E TE I L T L I E E E N R D A T P P P N P DP EN P N N N N N L H O E S M AM S M N I S M M M A A A A E O O O S O RO S O L L L V B C C C ECIRC EC P P P E S - D I L A VI O ER S R T S S F D PA - S C T E L C T O S A N SM W O E T T F NI 4,ST ECD L E L 4 I A H A I RE C L T , S T D S N4 I I F S E S N DO ,M ES M O F P A E F ALE PS F o SS N V E E V I A N Y G N O S H S V R U O S T HF RM S I SN F W EE O C T D I O R S ES S SLE G CS I D I C N A CN S N a E NE E T R AO E O E K i N H EHI P N J I T 4T H LD A V S L S H G GR A G S I T B GS G E FT T U N U W EN U D DC EC LSF O RT ,UWI H S I NO OE L AA N 4 E O DTTS E R E TD R E ,HL R P EOD A C aLOANITT C E W OE SE E R A E i R R I I T U R EWR- V AARL KF LE RR C D O AS UO UE R H U MD K I ST L CS T F T H U CEL AP NER M K CC TT I A TE NC AA CE A- TL C T C AD AE iH C AEI AA
RT c H H R E CA FS K S TT FR OD RA P RR S TI E 3 SF I O R 1 & 4 5 6 7 8 9 1 SO E o H S 2 ,' ,! i' f! ll l l
- 1
]i d , i d H , t i R E EN PV PC G N TR I WE ED C N n r OD W TN A o I CE L TO AA H L N E P U N E D AT O LS E R MS AS T AM NI AD T ER VE L EE EN U O A N L XR O RM H I L R U C GU O G W AF L LI R AS T U D FN E N DO . VLE T 0 U B EO LT L E^ EAS N A 8 b O V I C E W SD L TS L E- t I T T AD WD E F L L EE P Df RN FT O E I MV D N08 D E EA OA W W DR E I L - T P OP T D I NS L G5 5 C OU EA OU SLO E C N E E CO ER I TL EET N I SV P X R FR A NIN I I RWC A A C ' UA E R G E R D AN I E E H S DS E MN S 0 E 7 R N DO I NR NA AO XI UE I ) AT I O NF L 0 N LD EA T 7S I E N E D OW1 I T S SE L FE W & OW 0 4A T E L VU T FI S E DT WS B TI I P LC (S UD T O ALN I V EE L E YW OR A C U P D EU R WP X AV B& B B R E RW AH SD W NE T E 5 D E , AI C T S LA RN P NN OE MO VE N UT G A E F RRA T I D TR DP O, D AA I E I I EL L MR N NI DS NF T C EU OO HPD EP I A I E RE A A ES NE TPI C RR WN T 0UM I R BI AW L L I ST BYR OR EG VD 1 B F AA AS TG TW DY E I A CI WS S SN SL F RE G I R H I N SO I TE I OTR D , TMR E W SL W JAE NT LC . SEA TO H & AON EA E RO SHE XN B MCE DM I WNC HCT EK e e e e o e O , ;,; N L N OL I O S TE D E N S I R I AW O T E A D D S T A I M P N D I M A A R A H C A C E T O A R P A C T RE O R S T D C T I C R I N H C N 4 TN P U T T A O-SA T N P I 1 T OT S T E A F O W O T ) V P PS C T L S e U I N A N T P M E SE O C O F U 1 > S T EF I I C T I H) ) ( N T ARFE R S I T A SV e SV Ne c e E M U G E A Z iMa EM I P I L E P T R K1 M1> s. CG AIN T S E > I 2 EN O T &( C( mG PI VRA C S C c2 E /W cO S L A EAR L E R A K im c P 2 Smc no& EE L E A R DN - O L TN O B O ,U I Q A F HL E n Cr o ,/ H/ Tno trB - u- UN LA eA I C WDI CE I E NT L G) R H Nt u Ae Wr t nT A NN D S u 0 I O SA A I D% N w t R E E TR Tn S Ne On 1 0 D YIT E A S D 1R I 9 MIA I I A P AE S1 T9 XO RS A L 9 P O I D PP E0 R1 A1 T D EE R A4 C A U X R 10 U 5C KA RR SN R I C0 O5 F R-RN G N1 TX TA AE OR N H A WIT N V R I L3 O I RT S5 - OUA GS F 0 E U C AA S TR TS D ET ND C E NO OD GE I TO EN TC OA N E E P AT S TE I NR AU VA I T I T FW FO U I S R S E 2 A1 8 QD DE Y RT NT L I EP EE L O O D0 I AR P EC ED T T A1 EH ST A DA TN C T T BI RU N E I R XT UP RX AI UIM RT A (R WF ER DU R RW I C I 5 SL HA e o o e e e e TR 0F 1 O 1 ! h c W r E a I e V s R e d n s l E R eit r al a r u it V i sM s F i ut s q s er n O i s s lyP e . el r a a E ei r s it sl
- s. v ta f x M y s mn r a e r y e ne ma l l uf A a e e s pM i
u a r c r o R n s q wu m F e s ir l i eiEs r a s c n G A V pL y r e p e sidt o r O oe l r p x u a l o t e R e s0 e0 t h g a ed e su r w r l P T 5 nih n e o e a u v t v vl a d 4 o , ei t n i t y s o l t H r d a c n c i a wcl p e i o er tn xi t e r C a r V- le r a M mrp F a ase R i i P b oc P l f A F R ci f E sa m sam r e i o e e r u E s r e n s h d c d e u z g c isd r S n s si ss s s i lek s s r n n c i E a e er s se owio8 na oa g R r p e n er - c V n d o us V t cV kr Pi n d t S s aV z t niTI o R n s s s e de r U e hc R P c er e c r wro ap T er pf o i t r s p s L r r t f n t a rola o ek k S eF p s F . r r c a c a e u r r R - - C c c o o O 1 W E I V h n R c io E r msn V a o e O e f r t x s o e e e o , t v r k M R t a a u c A d e t a c ar R s y v d R c G e p r r u t s J f i o O t a c e g 2 r h t s R e C R - g it nt n P p n J i n 'lo u z o o ed en ly o pm H r wa a a P r a C t e , n a t x e R l b c r e g r A a s e n t o e r a E i r o y f v f ol S i s r o e t at r d u s t E t lei s o c d n R a r r m h t R h o e oe e M ch mJ - t ei m S c e mecp U d ea l dei n p s L vi r vo mr o o r e l l r e el a pt pt v a m me em im id D s o o o C li !I l l W E h I c V r 0 R a E e V s e O e r R t u a c t a M n a d r A o f y R i t et r h e G a t p O d g or O R P i l i t n p t s a ol u ia 's e V l o er T H vt t C e ea s e r m r R l a o A r A c f d n E s k S kr a c S a s a r E e mdo C R g hct h e r n e 2 4 t S a la L be m - - P U 0 8 E E L ei s e d sy i VT- ST S d i vl o a T I PPW r n P a - - - - o O I ,l l ll l l W E I o V ) G h t . R d O c E s n a Wa V is E B or p O oa t b M &p S I a d l A R M e a c P d A y h s n i ia v ( E ec R r ih l y a n b c G a a e t t w e t r l a O s i v s b u O R m e g n e r d ne l l P m mip r 'i w a o e u r g e l e h e H t . S p s i v e o v s e wiu C r pd e el o e d n s s s R f s s t t t i e ei A h c oev d e m t h a ei s E r a t n rpt h e e c m i S gS s nU e o j c d r mf E e eL b o o oo r ul c R l l a g s a c n d h n c e ci t s i n s a io S t e e u a i h i e u t U c h l h c c e h d ci v l o L at a r t r s f v e a a oe e r r i t t e eM s p l u e r s T e eS e oh M mfo R A R t t o o a B !l r , ~ j. .4,- ; ,l * . +. LOW UPPER SHELF ENERGY MATERIAL , IN REACTOR VESSELS'. PRESENTATION TO THE ACRS -B. J. ELLIOT O autY is. 1989 REGULATIONS 4 IMPLEMENTATION OF REGULATIONS STATUS OF CRITICAL PLANTS D x K- _ _ - . _ - - - _ - - - - - - -
- 6 Xo x
LOW CHARPY UPPER SHELF ENERGY (USE) FOR REACTOR VESSEL BELTLINE (RVB) WELDS - APPENDIX G, 10 CFR 50 REGULATORY REQUIREMENTS a RVB NATERIALS MUST HAVE CHARPY USE GREATER THAN 50 FT-LB UNLESS'IT IS DEMONS'iRATED IN A MANNER APPROVED BY THE DIRECTOR, OFFICE OF NUCLEAR REACTOR REGULATION, THAT LOWER VALUES OF USE WILL PROVIDE MARGINS OF SAFETY Q AGAINST FRACTURE EQUIVALENT TO THOSE REQUIRED BY APPENDIX G OF.THE ASME CODE WHEN CHARPY USE IS LESS THAN 50 FT-LB, THE LICENSEE MUST: - PERFORM 100% VOLUMETRIC EXAMINATION - PROVIDE IRRADIATED SUPPLEMENTARY FRACTURE TOUGHNESS DATA - PROVIDE AN ANALYSIS TO DEMONSTRATE MARGINS OF SAFETY l- TEST METHODS FOR SUPPLEMENTARY FRACTURE TOUGHNESS TEST MUST BE SUBMITTED TO AND APPROVED BY THE DIRECTOR, 0FFICE OF NUCLEAR REACTOR REGULATION TO .:: L - _ - - _ _ _ - - __- g,- ,- . - - - - - .- 91 , Ylh IMPLEMENTATION 0F REGULATORY REQUIREMENTS A e REQUIREMENT. STAFF ACTION IDENTIFY PLANTS WHICH HAVE PLANTS-IDENTIFIED:IN A SEPT. 24, . LOW ~CHARPY USE PROBLEM 1987 LETTER TO MURLEY FROM STAROSTECKI'- TURKEY PT, 3 8.4, POINT BEACH I a 2, AND GINNA PROVIDE INDUSTRY WITH A NUREG-0744, " RESOLUTION OF THE -EETHOD FOR EVALUATING LOW TASK A-11 REACTOR VESSEL MATERIALS CHARPY USE WELDS. -TOUGHNESS SAFETY ISSUE,";0LT. 1982 SUPPLEMENTARY VOLUMETRIC REGUL.PiORY GUIDE 1.150, " ULTRA-EXAMINATION' REQUIREMENTS SONIC TESTING 0F REACTOR VESSEL hFORBELTLINEWELDS. WELDS DURING PRESERVICE AND INSERVICE EXAMINATION," FEB. 1083 SUPPLEMENTARY FRACTURE INITIALLY USED DATA FROM HSST TOUGHNESS DATA PROGRAM - WIR PROVIDE TEST DATA FROM A COMMERCIAL REACTOR THROUGH. BWOG - STAFF MEETS PERIODICALLY WITH BWOG TO REVIEW PROGRAM AND TEST RESULTS , TEST METHOD REVIEW STAFF APPROVED BWOG METHOD ANALYSIS TO DEMONSTRATE LICENSEE INDICATES PLANT CAN MEET MARGINS OF SAFETY SAFETY MARGINS FOR 40 EFPY -- STAFF Q AGREES WITH CONCLUSION BUT REQUESTS .. ADDITIONAL INFORMATION '[, l T " " " " LA . . LT L T I A P C WD P A U R S F S I G S GO Y S EW L C EB A I U N N NED A A SO O H S RUH G T C I E T O E S PLE " W " " D M Y LM B E, L DI T E A EWS E A R N T I S L U A T- S UD U T I Y O C C M4L LH L A B4A LT A . R U7N I E C 3 F S0A WM E 1 S . Y % U. T L 0 F S L 0 - 9 Y . D A 1 1 2 9 8 P 0 L C 80 80 80 70 90 R 5 E I D 95 95 95 85 15 A W R E 11 11 11 91 1 L oH . 1 . . N T N . . 1 I1 C A E E I Y1 Y1 L1 H T M M L L L Y R l l T A U A UG UG AG AG PG I D L X JR JR FR MR AR I S O E WS V E S L T N N E O A B I E L T G P C M U A S S S S A F D R R R R R K O E G MNE MNE MNE MNE A R O UOB UOB UOB UOB E S R I RR IRR I RR IRR LS U X P NTO NTO NTO NTO E T U FUS FUS FUS FUS WR A L AEB AEB AEB AEB OO T F HNA HNA HNA HNA LC S-E 9 D C 8 L ) N / E V E 1 H E U / M L 1 L I 9 9 9 9 9 F A 1 1 1 1 1 N C E E E E E E H O I / 5 5 8 8 2 O T 8 8 0 6 1 R T I M . . . . T A R C 0 0 J 0 1 U C / E T N N A T ( A O Y ET 3 Y ET 4 TH 2 TH I A T N KN KN NC NC N A RI RI IA I A N L UO UO OE OE I P TP TP PB PB G l o u,. , Y, . : , TURKEY POINT FRACTURE MECHANICS ANALYSIS i ANALYSIS METHODS PER NUREG-0744, " RESOLUTION OF THE TASK A-11 REACTOR VESSEL MATERIALS TOUGHNESS SAFETY ISSUES", OCT. 1982 EXTRAPOLATION OF IRRADIATED HSST DATA LEVEL A 8 B SERVICE CONDITIONS O
- SURFACE ELLIPTICAL FLAW 11.625 X 1.9375 INCH (AXIALLY ORIENTED) IN A CIRCUMFERENTIAL WELD PRESSURE OF 5000 PSI 100*F/HR. C00LDOWN RATE
- ACCEPTABLE FOR 40 EFPY, FLUENCE OF 1.73 X 10 19 N/CM (E IMEV) AT 1/4T LOCATION i (b ) ..' .
- e a
h.- m_.__-_ _ _ . _ _ _ .m-_ _ _ _ _ _ . . _ _ . . - _ _ _ . . - . . . d l s n o s e ia s t n ast s en o t e r ol l d t i anV heiA i t ed D e r Tareor sn d mo et U C o n r c spf e ai u a q e t eOs a e b e s s ieR l c a c l l i n sR i n e y e d n m r r e Wc i Y ayh or l I n o r t sN c u t aL R At a f i af o o sg c oA I ,l uy l y . nO D d M S gt air e n O erg i n ul cE M AD an n s R e at U myt n ssi o l l a af cnt iia i e s S r s I n g r s vr n gt i e arap etn uig oar r Su h a S r P - s cMOl e a n P aM l ) 's nE Mladeg i o i t c e ei t eii l l en r t ai n r e t s i sW t utapt a i mu a n u c bscr eqd a i t e mla ccn r un p ov i L Aa FSAO CE O a a a f" f \% ACRS EETING JLLY 13,1989 EXTERNAL BERS FIRE stb-C0fMIT7EE STAlllS REPORT I MCCRAG O! OilEF CONRAD PLAtT E,SYSTBdS BRANCH OFFICE OF NUCLEAR REAC10R REGl'LATION 1 E_______.___ _ _ y' -- m q i M. f, STATUS OF COMPLIANCE WITH PEGlLATIONS { . APPENDIX R If6PECTIONS CONDUCTED AT ALL APPLICABLE PLANTS FINDINGS IN SEVERAL CASES WERE THAT IIREENTATION WAS INADEQUATE. TESE WILL PECEIVE A CCIRETE E-INSPECTION - PRE-0PEPATIONAL' INSPECTIONS CONDUCTED AT ALL PLANTS f0T UNDER APPEt0lX R COMPLIANCE EQUIRED PPIOR TO STARTUP Q, TRI-ANNUAL AUDITS NOW PEING IMPITEFTED AT ALL PLANTS IN Sl!PARY, ALL PLANTS CURRENTLY MEET 'IliE EGULATIONS OR WILL DO SO SHORTLY PLABTIS FOUND NOT TO MEET EGULATIONS WILL EE EQUIRED TO DO SD O v / . o .- . .-t 2 43 '% l - ( , EFFORTS BEYOND THE REGULATIONS SEVERE ICACTOR ACCIDENT FOLICY STATEPD(T: EXPEuta TO PERFORM A LIMITED-SCOPE ANALYSIS TO DISCOVER PARTICULAR VULNERABILITIES EXTERNAL EVENTS STEERING COMITTEE (EESG) F0PMD TO PROVIDE DIPECTION ON IMPLEINATION OF POLICY. O
- EXTERNAL EVENTS FIRE SUB-C0mITTEE PROVIDES REC 0ffENDATIONS TO EESG PLANT SPECIFIC VULNERABILITIES TO BE ADDPESSED THROUGH BACKFIT PROCESS ;
.q l 1 (L O l l L - _ __ _ _ _ . _ _ I 0; FIRE SUB-CDfEITTEE FINDItGS EACH ORRATING PEACTOR SPOULD BE EVALUATED TO DETEPHINE PLANT SKCIFIC VULNERABILITIES TO INTERNAL FIPES -INDUSTRY. ERFORKD PRAs DEMMTPATE THAT FIPE CAN BE A SIGNIFICANT CONTRIBlff0R.TO COE FELT SOE VULNERABILITIES IDENTIFIED THROUGH THE PPA PROCESS WERE CORRECTED PRIOR 1D REPORTIfC ^ ' FIPE RISK SCOPING STUDY RESULTS IfDICATE THE POTENTIAL FOR PLANT SRCIFIC VULNERABILITIES. A LEVEL 1 PRA IS AN ACCEPTABLE ETHODOLOGY.T0 NPF0PM TE EVALL'ATION FOR FIPE VULNERABILITIES i' - .0THER ETliODOLOGIES MAY BE ACCEPTABLE Biff PE0UIPE RIPTHER -DEVELOPENT _Q-LIMITATIONS EXIST IN APPLICATION OF FIRE SPREAD CODES. HCvEVER, IN THE FEW LOCATIONS RR PLANT WHERE THIS IS AN ISSUE ENGINEERING EVALUATIONS CAN BE CONDUCTED 1 O L_ _ ___ _ _ - - v }, p
- i. FIRE RELATIONSHIP TO I E FIRE DOES NOT CREATE A NEW ACCIDENT IT INCREASES THE PROBABILITY ON EXISTING OES. THEFEF0E, FIPE RESOLllTION MUST BE COMPATIBLE
-WITH PLAfff SPECIFIC INTEPNAL EVENTS PESOLUTION GL 88-20 PERMITS: PPA ENHANCED IDCOR OTHER SYSTEMATIC METHODS FOUND ACCEPT /6LE BY STAFF O O ! . /~ s 'u; FIRE RESOLUTION FOR ALWRs i PLANTS ttST BE CAPABLE OF SAFE SHLTTDOWN ASSUMItG TOTAL LOSS OF ANY ONE FIRE AREA, ASSlfilNG NO OPERATOR RE-ENTRY (PEACTOR CONTAlfMNT BilILDING EXCLl0ED WITH SRCIFIC REVIEWS) 20 FOOT SEPARATION CRITERIA IS ELIMIffATED Sf0kE MUST BE CONSIDEPED O O L COURSE OF ACTION FOR IDENTIFICATI04 OR FIRE VULNERABILITIES THE NO.1 PRIORITY IS TO GET EXAMINATIONS CONDUCTED TO IDENTIFY VULNERABILITIES-FINDINGS WILL BE CROSS CECKED STAFF IS WORKING WIE NLFARC/EPRI TO DEVELOP AN ACCEPTABLE ETHODOLOGY BY THE END OF C.Y. 1989 TO BE USED ON TWO TEST PLANTS BY 9/90 NUEG-1150 SANDIA ETHODOLOGY COMPATIBLE WITH FRA PLAfffS ALTERNATIVE ETHODOLOGY COMPATIBLE WITH EhNANCED IDCOR Ato OTHERS APPLICABLE FIRE RISK SCOPING STUDY PESULTS TO BE INCLUDED IN ETHODOL0f / - ANALYTICAL CODES: ADE00 ATE TO SEARCH, REFEPENE TABLES BEING O PEPARED USING CCFFBURN III, MAGIC, AND ENGINEERING JUDGEENT - SEISMIC /FIE INTERACTIONS; PROCEDURALLY DIRECTED WALKDOWN - FIE BARRIER QUALIFICATION; INDIVIDUAL PLANTS JUSTIFY ASSUMPTIONS - MANUAL FIPE FIGfflNG EFFECTIVENESS; INDIVIDUAL PLANIS JUSTIFY ASSUMPTI0fS -- TOTAL ENVIRONENT EQUIPENT SURVIVAL; 1) COMBUSTION PRODUCTS AND SUPPRESSANT EFFECTS NOT ADEQUATELY DEFINED. 2) FIE SUPPRESSION SYSTEM EFFECTS ON SAFE SHUTDOW EQUIPfBT TO BE INCLUDED IN PLANT WALKDOWN. 3) GI 57 RESOLLTTION IS BEING COORDINATED WIE IPEEE. CONTROL SYSTEMS It!TERACTIONS: INDIVIDUAL LICENSEES CERTIFY THAT THEY , EET REGULATIONS AND INF0Pl% TION NOTICES O ' r , ,. j OL ACRS AGENDA ITEMS (CONTINUED)- < 1 o A. 6/23/88 LETTER FROM C, MCCPACKEN TO EESG I - PROVIDES FIE SUBCOfNITTEE PECOMENDATIOFS L B. 12/28/88 LETTER FROM GILLESPIE TO BECKJ0RD INCORPORATES FIE RISK STPING SRIDY RESULTS INTO IPEEE 4 POES NOT FORSEE A CURPUT PEGULATORY NEED FOR ADDITIONAL WORK C. SECY 89-170; JUNE 7,1989 IFFORMS COPMISSION THAT FRSS ISSUES TO BE ADDRESSED IN IPEEE - NO NEW FIE ES AT THIS TIE, WILL BE RECONSIDERED BASFD ON NUPEG-1150 PEER REVIEW AND ACRS DISCUSSIONS O L e O