ML20155B789
| ML20155B789 | |
| Person / Time | |
|---|---|
| Issue date: | 06/02/1988 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 8806130342 | |
| Download: ML20155B789 (84) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
Title:
BRIEFING ON MASTER PLAN FOR INTEGRATING ALL SEVERE ACCIDENT ISSUES Location: ONE WHITE FLINT NORTH, ROCKVILLE, MARYLAND Date:
THURSDAY, JUNE 2, 1988 Pages:
1-64 Ann Riley & Associates Court Reporters 16251 Street, N.W., Suite 921 Washington, D.C. 20006 (202) 293-3950 l
8862?88?ii""^"
PT9 7 PDR
DISCLAIMER This'is an unof.ftcial transcript of a meeting
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4 of the United States Nuclear Regulatory Commission held 6-2-88 in the Commission's office at One a
on White Flint North, Rockville, Maryland.
The meeting was open to public attendance and observation.
This transcript has not been rev'iewed, corrected or edited, and.it may contain inaccuracies.
The transcript is intended solely for general informational purposes.
As provided by 10 CFR 9.103, i t is i
not part of the formal or informal record of decision of the 4
matters discussed.
Expressions of opinion in this transcript do not necessarily reflect final determination or beliefs.
No pleading or other paper may be filed with the Commission in any proceeding as the result of, or addressed to, any 4
statement or argument contained herein, except as the Commission may authorize.
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1 1
1 UNITED STATES OF AMERICA 2
NUCLEAR REGULATORY COMMISSION 3
y.
4 BRIEFING ON MASTER PLAN FCR INTEGRATING ALL j
5 SEVERE ACCIDENT ISSUES
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6 7
PUBLIC MEETING i
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l 8
9 Nuclear Regulatory Commission i
10 One White Flint North 11 Rockville, Maryland I
l 12 13 THURSDAY, JUNE 2, 1988 14 1
15 The Commission met in open session, pursuant to 16 notice, at 10:00 a.m., the Honorable LANDO W.
ZECH, Chairman of 17 the commisalon, presiding.
l 18 19 COMMISSIONE'RS PRESENT:
I 20 LANDO W.
- ZECH, Chairman of the Commission 21 THOMAS M. ROBERTS, Member of the Commission
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22 KENNETH CARR, Memb6r of the Commission 23 KENNETH ROGERS, Member of the Commission l
24 i
25 i
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STAFF AND PRESENTERS SEATED AT THE COMMISSION TABLE:
2
'3 S. Chilk 4
V. Stello 5
T. Spels
+
6 W. Parler 7
T. Murley 8
A. Marchese 9
10 AUDIENCE SPEAKERS:
11 12 J. Murphy 13 j
14 i
15 16 j
17 18 19 20 21 22 23 24 25
3 1
PROCEEDINGS 2
(10:00 a.m.)
3 CHAIRMAN ZECH:
Good morning, ladies and gentlemen.
4 Today the commission will be briefed by the Nuclear Regulatory 5
Commission's Office of Research and the Office of Nuclear 6
Regulatory Regulation on the integrated plan for closure of 7
severe accident issues.
8 The integration p1.an is a description of all severe 9
accident programs currently being undertaken by the Commission.
10 It describes how the Agency will reach clos,ure on these 11 programs and describes the interrelationship among the various 12 programs.
13 The main motivation behind the development of an 14 integration plan for closure on severe accidents was to assure 15 the consistency between programs and consistency with 16 Commission policy and strategic goalt 17 It's my understanding that there are six main 18 elements of the plan, which include individual plant 19 examinations, containment performance improvements, impvoved 20 plant operations, severe accident research pr ogram, external 21 ovents, and accident management.
22 The Commission is interested ir. hearing how 23 consistency between programs is maintained, the 24 interrelationship between programs and policy implications of 25 each program.
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4 1
Additionally, we would be interested in hearing how 2
the resolution of severe accident issues may impact the backfit 3
rule.
7_
4 It is uy feeling that the backfit rule has been 5
providing some order of discipline to the backfit process and 6
is working quite well, but we would like to hear from the staff 7
in that regard.
8 This is an information briefing today and no 9
Commission vote is anticipated.
Do any of my fellow 10 Commissioners wish to make any opening aumments?
11 (No response.]
12 CHAIRMAN ZECH:
If not, Mr. Stello, will you proceed, 13 please.
14 MR. STELLO:
Yes, Mr. Chairman, and thank you.
The 15 meeting this morning I think is very, very important and the 16 paper that is now before the commission I think is also very 17 important.
18 over the years, a number of issues have been raised 19 with respect to severe accidents.
The idea behind the paper 20 and the need for the paper became apparent af ter one started to 21 ask the question of how do you get to the end of the process, 22 when and what has to be accomplished to achieve closure of the 23 severe accident issues, the satisfying of the Come.Assion's 24 policy statement on severe accidents.
25 The paper is intended to show you the relationship so
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1 that as the various pieces are before the commission, the i
2 Commission will better understand how each of those particular 3
issues fit together and when is it that we will be able to 4
finally conclude that we are done with the severe accident 5
issues and find that issue closed.
6 You raised at the outset a question that I think is a 7
very, very important question and that's the process of how we 8
are going to make decisions regarding what additional 9
modifications might be needed for the facilities.
10 The commission has issued guidance in this matter in 11 two forms at the moment.
The first is in the commission's 12 backfit rule, which you have already indicated has given a 13 structured philosophy and policy of how to proceed with backfit 14 issues.
15 At the same time, the commission has also given us 16 some guidance with respect to safety goals.
We intend to use 17 both the backfit rule and the commission's safety goal policy 18 to the best of our ability to do so.
4 19 We have, however, recognized that in dealing with 1
20 severe accident issues, it may be that the backfit rule or the 21 policy statement dec. not adequately cover any particular issue
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22 that we're going to be dealing with.
23 And on Page 18 of the Commission paper, we 24 particularly tried to make the point that if we ever came to a 25 point where we thought something needed to be added to a
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facility and it were an issue that we believed more work needed 2-or modification, even if the backfit rule did not, if you will, 3
pass that test or the commission's safety goal policy did not j
4 provide enough guidance.
5 For those cases, we would come to the Commission on a 6
case-by-case basis, present the issue to the Commission for the 1
7 Commission's decision so that --
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COMMISSIONER ROGERS:
Aren't you talking about 9
specifically the Mark 1 issue?
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10 MR. STELLO:
Well, that could be, but let me be more 11 specific than that.
Some of the plants that we are now 12 analyzing, and I guess forecasting some results that have not 13 yet even been published on NUREG 1250, some of the core melt 14 frequencies are approaching ten to the minus six.
15 If you look at the Commission's safety goal policy, 16 the most stringent requirement in that safety goal policy would 17 suggest that a plant should have a frequency of less than ten 18 to the minus six for a significant release.
19 Well, clearly if the core melt fregt ency is ten to 20 the minus six, you're going to meet that one and you meet all 21 other safety goal requirements.
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22 If you then start looking at the backfit rule in 23 terms of analyzing it for cost benefit analyses, at ten to the 24 minus six for a core melt frequency you're obviously 25 substantially less for any kind of a release, and when you work
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out the equations, you're going to wind up with very few 2
dollars which could justify doing anything.
3 Well, if there is a particular dominant sequence that i
4 is still remaining in Grand Gulf that judgment would suggest 5
you might want to do more, then that is the kind of an issue we 6
would clearly ~ bring to the Commission.
i 7
With that, Mr. Chairman, and I think perhaps we ought 8
to talk some more about what is the meaning of Page 18 so that 1
9 we are clear on what our intent is and if there's more guidance 10 by the Commission on that it would be useful for perhaps the 11 Commission to make sure that we understand it.
12 I will then ask Dr. Speis to go through the 13 presentation and this is the kind of presentation, I think it's 14 probably a useful idea to stop whenever something is necessary 15 for clarification and try to do it at that point so we're 16 prepared to answer all of your questions at any point in the 17 presentation.
Themis?
18 CHAIRMAN ZECH:
All right.
You may proceed.
19 MR. SPEIS:
Mr. Stello, Mr. Chairman, Mr.
20 Commissioners, I will start with some background of this effort 21 on Page 2 of the viewgraphs that you have in front of you.
22 If you recall, on August 8, 1985, the Commission 23 issued the severe accident policy statement.
In it, the 24 Commission concluded that existing plants pose no undue risk to 25 the public.
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That conclusion was reached after extensive 2
evaluations involving severe accidents and the research that 3
was done after that time.
4 At the same time, however, based on NRC and industry 5
experience with plant-specific probablistic risk assessments, 6
the Commission recognized that systematic examinations will be 7
beneficial in identifying any plant-specific vulnerabilities to 8
severe accidents for which further safety improvements may be 9
justified.
10 In February '86 we presented to the commission an 11 implementation plan for the severe accident policy statement 12 which addressed the specific issues that were raised in 50 FR 13 32138.
14 At the same time, we provided some additional 15 information to the Commission in two SECY's dealing with the 16 treatment of external events in severe accidents as well as how 17 does one evaluate a source term in a realistic sense.
18 In February '87, the Commissioners asked EDO to 19 provide an integrated plan for some of the issues that they 20 were discussing at that time, and at the beginning of '87, EDO 21 provided to the Commission a preliminary plan for integration 22 of some of the severe accident issues.
23 Finally, last year Mr. Murley from the Office of NRR j
24 and from the Office of Resource, briefed the Commission on the 25 plan for closure of severe accident issues, including issues i
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relating to BWR Mark I containments.
2 If you recall, Mr. Chairman, at that meetjag the 3
staff indicated its intent to pursue an integrated approach to 4
resolutica of severe accident issues, which I'll say more about 5
when I come to the issue of containment performan'ce 6
improvements.
7 In December '87, we presented to the Commission our 8
plan to resolve the severe accident issues relating to the 9
containment performance, starting with Mark I.
That was 10 described in SECY 87-297.
11 Finally, the EDO assembled together a number of 12 senior NRC managers at the beginning of this year, from the 13 Offices of RES, Nuclear Reactor Regulation, and the Office of 14 AEOD, to discuss the whole spectrum of severe accident issues 15 with the primary emphasis on how to proceed with the 16 implementation of the Commission's policy statement.
17 Putting this plan together was a result of that 18 Baltimore meeting.
On the second page, on Page 3 of the 19 handout, I want to kind of outline the objectives, even though, 20 Mr. Chairman, you discussed them already.
21 Basically, the purpose of the integration plan is to 22 present the staff's plan, how to integrate all the issues and 23 how to proceed with the closure of severe accident issues.
24 The objectives are, a number of them, to provide an 25 understanding of th'e staff activities, both the main ones and
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the supporting elements that are underway to implement the 2
Commission's severe accident policy and to assure that these l
3 activities are consistent with the Commission's policy and 7_
4 overall strategic goals.
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5 It's important to assure that these activities are 6
consistent among themselves, have a common goal which is to 7
ultimately lead to improved plant safety and are properly 8
coordinated among the responsible NRC organizations, and to 9
assure that the Commission is aware of the key technical and 10 policy issues, some of which will meet Commission guidelines 11 for approval, and finally to describe the use of safety goals 12 and backfit policy in the closure process.
13 I think Mr. Stello already mentioned, but I think 14 it's important to stress that this paper presents the 15 information, describes it, and tells you when the different 16 packages with be reaching the Commission for decision-making.
17 There is no need to make any decisions on this paper 18 itself today.
The severe accident integration plan provides 19 for a number of coordinated activities to ensure fulfilliaent of i
20 the severe accident policy.
21 These activities, which are addressed in the
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22 integration plan, are listed in the next viewgraph. on Page 4 23 of your handout.
24 Basically, the main ones are the IPE, the individual 25 plant examinations, the containment performance improvements
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program, which will start with the Mark I's and complete the 2
cycle of the different types of containmen'ts by the end of next 3
year, improved plant operations, the severe accident research 4
program, external events, and accident management.
5 The supporting activities are such reports as NUREG 9
6 1150.
Of course, the generic safety issues and the integrated 7
safety assessment program, ISAP.
8 The severe accident policy for future plants is also 9
addressed in this commission paper and, of course, the process 10 of closure and how we plan to utilize the safety goal in that 11 process.
12 The next page, I have a schematic illustration of the 13 severe accident integration plan and basically completion of 14 the elements of this plan constitute the basis for assuring 15 that the residual risk to the public from severe accidents of l
16 the nuclear power plants are minimized.
17 We already repeated the six main ac':ivities.
You see 18 that all of them fit directly into the severe accident closure.
19 The individual plant examination, which includes both 20 internal and later on the external events, on the left, the 21 middle left.
22 Above it, improved plant operations.
They also fit 23 into the severe accident closure via improved tech specs, via improvement in the procedures existing, emergency operating 24 25 procedures, and reaching them with accident management
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procedures which I'll discuss later on.
2 Also, at the lower part, you see the potential 3
containment improvement, starting with Mark I and going into 4
the other ones, and they also lead directly into the severe 5
accident closure.
6 Now, to summarize at this point, severe accident 7
closure is achieved once the IPE's, the individual plant 8
examinations, have been completed, including external events, 9
and any appropriate changes implemented.
10 A framework for an accident management program has 11 been developed and implemented and any generic requirements 12 resulting from the containment performance improvement programs 13 have been implemented.
14 Later on, I'll discuss in some more detail the 15 closure process.
Now, besides the main elements listed here, I 16 already mentioned the supporting elements, for example the 17 1150, which provides information and insights that help us in 18 the decisions that have to be made as part of the main 19 elements.
20 Also the backfit and the safety goal policy provide 21 guidance and constraints in defining the implementation i
22 strategy for these main elements basically.
23 And the next viewgraphs, Mr. Chairman, I'd like to 24 summarize some of the main activities of the integration plan -
25
13 1
CHAIRMAN ZECH:
Before you on there, let me interrupt 2
you just a moment.
3 MR. SPEIS:
Yes.
g_
4 CHAIRMAN ZECH:
This integration effort, I think, is 5
extremely important and very significant.
I have mentioned the 6
backfit issue in my opening remarks and Mr. Stello, and now 7
you, Dr. Spels, also referred to the backfit issue as it 8
applies to this integration process and this effort that we're 9
undertaking.
10 Let me give you at least what I understand, there are 11 provisions regarding the backfit rule, and ask for your 12 comments to see if you would agree because the effort to 13 integrate these different efforts towards improved public 14 health and safety are extremely important.
15 And let me just ask you if you would agree, at least 16 with my understanding, and for my colleagues too, with at least 17 my brief summary of the backfit process as I see it applying to 18 this integration program.
19 And although the backfit rule, as I understand it, 20 does require an analysis of the safety benefits in relation to 21 the cost, and it does put discipline into the system, the 22 backfit rule does not preclude the Commission from taking a 23 regulatory action to improve safety.
24 MR. SPEIS:
Yes, sir.
25 CHAIRMAN ZECH:
Is that correct?
14 1
MR. SPEIS:
Yes.
2 CHAIRMAN ZECH:
And therefore, as I understand it 3
then, the staff should and would bring to the Commission's 4
attention any proposed significant generic modification for a 5
Commission decision, even though it may not meet the backfit 6
rule.
Is that correct, too?
7 MR. SPEIS:
That is correct.
8 CHAIRMAN ZECH:
And I think that's very important to 9
recognize as we discuss integration.
And I think, at this 10 point, I should emphasize, too, the recent emphasis we've 11 placed on the backfit rule and emphasize, too, that there are 12 three conditions where the backfit rule would not apply.
13 The first, of course, is where modifications are 14 needed to bring the facility into compliance with our 15 regulations.
The backfit rule, no cost consideration applies.
16 MR. SPEIS:
Yes, sir.
17 CHAIRMAN ZECH:
The second would be where the 18 modifications are necessary to assure adequate protection of 19 public health and safety.
Backfit rule, no cost considerations 20 in that regard.
21 And the third would be where modifications involve 22 determining what the adequate level of protection, public 23 health and safety protection, is -- in other words, if there's 24 a concern about needing adequate protection, public health and 25 safety, then the backfit rule would not apply in that regard
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either.
2 Is tha+. Correct, too?
3 MR. SPEIS:
Yes.
4 CHAIRMAN ZECH:
All right.
Well, those are 5
important, I think, as we consider now your further 6
presentation of the integration of these very important severe 7
accident related issues.
8 So will you proceed?
9 MR. SPEIS:
Yes.
Starting on Page 6, Mr. Chairman, I 10 would like to summarize some of the main activities of the 11 integration plan as well as some of the supporting ones.
12 I will start with the individual plant examination 13 which flows directly from the Commission's policy statement of 14
'85 where a plant-specific examination will be undertaken.
15 And the Commission, at that time, told us to go ahead 16 and work with the industry to formulate and integrate it, 17 systematic approach to an examination of its nuclear power 18 plant, now operating or under construction, for possible plant-19 specific vulnerabilities that might be missed without such a 20 systematic search.
)
21 As I said earlier, previous PRA's always identify
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22 something, items that could be improved.
The examination, also 23 the commission at that time said that the examination will pay 24 specific attention to containment performance in attempting to 25 strike a balance between accident prevention and consequent
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mitigation.
2 In fact, it's in this area that possibly, as we go 3
down the road to examine containment performance improvements, 4
it's possible in some of those areas, in attempting to strike a 5
balance, we might find out that in some cases the expenses to 6
pursue such affixes might go beyond the backfit policy, in 7
addition.
8 Those areas that will come to you on a case-by-case 9
basis.
You know, that's an example for them.
The examination 10 will be requested via a 10 CPR 5054F letter.
11 Again, as I said, the basis for the examination is 12 the Commission's policy statement.
We have interacted 13 extensively with industry and developed appropriate 14 documentation for this examination.
15 Later on, I'll discuss what type of methodology could 16 be undertaken to do this examination, could be utilized rather, j
17 Now, the purpose of this examination ~13 for the utilities to 18 identify and understand the most likely severe accident 19 sequences that could occur at their plant and the utilities 20 should take the initiative to evaluate and implement any means 21 for further improvements to the residual risk that we're 22 talking about.
23 It's very important to develop an awareneus of severe 24 accident behavior.
Now, it is expected that it would take 25 about three years to complete and evaluate the examinations
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conducted in accordance with the individual plant examinations.
2 I will continue on the IPE, on Page 7 of the handout.
3 It is very important that the licensee staff should participate
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4 in all aspects of the IPE, the individual plant examination, so S
that knowledge gained becomes an integral part of operating, 6
training, and procedural programs in their plants.
7 COMMISSIONER CARR:
Are you going to require that?
8 MR. SPEIS:
It is strongly urged.
9 COMMISSIONER CARR:
I guess that means no.
10 MR. SPElS:
Well, it's part of the package that will 11 be coming to you at the end of this month.
We feel very 12 strongly about that.
I guess maybe I'm not an expert linguist 13 14 COMMISSIONER CARR:
No, no.
I agree.
I feel 15 strongly about it, too.
16 MR. STELLO:
I think we're about as close to saying 17 that's the way it ought to be done.
18 COMMISSIONER CARR:
Well, if we believe that's the 19 way it ought to be done, why don't we just say that's the way 20 to do it?
21 MR. STELLO:
Maybe that's what we will wind up with 22 in the package we send the Commission.
23 MR. SPEIS:
Now, the licensees should conduct a i
24 systematic examination of plant design, operation, and 25 maintenance and emergency operations to identify plant-specific
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vulnerabilities, attempt to quantify the results to the extent 2
possible for the sequences that contribute the most to the 3
total core damage as well as to large release frequency, 4
understand what could probably go wrong in the plant, what 5
could possibly go wrong in a plant, and identify and evaluate 6
means for improving plant containment performance.
7 And then the licensee should decide what improvements 8
will be implemented and proceed to schedule such 9
implementation.
10 Now, the IPE generic letter was reviewed by CRGR on 11 4-18-88 and by the full ACRS Committee on May 5, 1988, even 12 though they had also reviewed the preliminary package of the 13 IPE last year.
14 With that summary, I would like now to go to the 15 containment performance improvements program on Page 8 of the 16 handout, Mr. Chairman.
17 As a result of concerns related to the ability of 18 containments to withstand some generic challenges associated 19 with some very low likelihood severe accident scenarios, we 20 have in parallel with IPE undertaken a program to determine 21 what, if any, action should be taken to reduce the
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22 vulnerabilities of containments to severe accident challenges.
23 I should like to point out that this evaluation 24 involves generic challenges and does not involve plant unique 25 with the primary focus of the IPE's, but those two programs
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compliment each other and there is no intent to undertake any 2
containment performance improvements if any are found to be 3
needed without a close integration and coordination with the 4
IPE process itself.
5 okay.
That's very important and we articulate that 6
as much as possible in the Commission paper itself.
It's an 7
issue that has been raised, whether we have two separate 8
programs, and it's really one program.
9 The focus, again, is to -- I'm sorry.
I would like 10 to say that this program was described to you in a commission 11 paper about December of '87, SECY 87-297.
12 Again, it focuses on evaluating generic challenges 13 and as part of that you have to understand the failure modes 14 and we're also evaluating potential improvements.
15 We're staring this program with Mark I.
Our approach 16 that we are pursuing, the approach that we are pursuing 17 involves both accident prevention and mitigation.
18 It's an integral one.
We'll look very carefully at 19 what additional things can be done to further reduce the core 20 damage, core melt probability, what things can be fashioned in 21 an accident strategy way to not only prevent an accident, but l
22 possibly if one is initiated to arrest it, or if you fail 23' there, what things can be done to further reduce the threat to 24 the containment or even reduce the source term that might be 25 released given a severe accident.
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5 20 1
So again, I want to stress that this approach is a 2
very integral one and it involves both accident prevention, l
3 accident management, accident mitigation.
4 For example, we're exploring additional sources of 5
water for both core cooling and possibly for containment and j
6 debris cooling and fission product scrubbing.
7 We're looking at things like utilizing existing 8
systems, like fire water sprays, to connect them to the 9
residual heat removal system or to the sprays themselves.
1 10 We're looking at improving the reliability of the 11 automatic depressurization system.
If you depressurize, jf 12 their liability is high, them you're able to introduce the 13 water into the system because you have low pressure systems 14 available in a power plant.
15 We're also looking at venting.
All of us have heard 16 quite a bit about venting.
For Mark I's, we're looking at the 1
17 suppression pool as the filtering medium.
18 We're looking very carefully at the pluses and 19 minuses of venting and we're not focusing on venting itself.
20 on all of these things, we're performing regulatory analyses 21 and we will be giving you a preliminary report of this effort
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22 by the end of this month or some -- I guess at the middle of 23 July, and our final recommendations from this will be to you at 24 the end of this summer, Mr. Chairman.
25 MR. SPEIS:
So that's a partial summary of the i
21 1
program, and I'd like now to go to the improved plant j
2 operations program.
On page nine.
If you recall, the 3
Commission's approach to safety was dramatically changed 4
following the TMI-2 accident.
Our emphasis shifted from i
5 providing safety by relying on the traditional design basis 6
approach to a multi-faceted approach which emphasized improved 7
operations, a human factor considerations, a realistic 8
performance of systems, and performing probabilistic risk 9
assessments to uncover weaknesses or strengths in the design 10 which can be farther improved.
l 11 This program, it's very important, it's the bread and 12 butter of really, of the Nuclear Regulatory Commission, and Mr.
13 Murley here has spent I guess 110 percent of his time in this 14 effort.
And so do our regions.
So this program to include 15 plant operations considers the following efforts.
And this is, 16 of course, it's not complete.
Continued improvement of the 17 systematic assessment of licensee performance, the so-called 18 SALP process.
Our regular reviews by senior NRC managers of 19 problem plants to identify and evaluate those plants that may 20 not be meeting NRC and industry standards and operational 21 excellence.
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22 Team inspections to probe farther the performance of 23 those plants identified involved that possibly do not meet the 24 NRC and industry standards.
Regulatory actions to improve 25 operational performance where it has fallen below expected
22 1
standards, improved technical specifications, continued 2
improvement of operating procedures, expanding the emergency 3
operating procedures to include guidance on severe accident 4
management strategies, I'll say more about that shortly.
And 5
research to establish the sensitivity of risk to human errors 6
including the contribution of management at the level of human 7
errors.
8 This is, of course, improved plant operations is, as 9
I say, it's an ongoing program.
It's the bread and butter of 10 NRC.
And we don't foresee any specific additional actions on 11 your part as far as this program is concerned.
I don't know.
12 If Mr. Murley wants to add anything to this brief summary that 13 14 MR. MURLEY:
Well, we will have a paper to the 15 Commission probably within a month or two, on accident 16 management, which is an integral part of the improved plant 17 operations.
And, as you know, a lot of what we're doing, tech 18 spec improvements, we're now looking at improving, actually 19 reducing surveillance testing requirements during operation.
20 Improved emergency operating procedures.
A lot of the stuff 21 that NRR does bears on this key part of closing severe accident 22 issues.
23 MR. SPEIS:
How I'd like to summarize the severe 24 accident research program.
The severe accident research 25 program was begun af ter the TMI-2 accident to provide the j
t
23 1
Commission and NRC staff with the technical data and the 2
analytical methodology needed to address the severe accident 3
issues.
Initially, the work was oriented to phenomena to gain 4
more insight into the' mechanisms of the different processes 5
involved, given a severe accident, and consisted of a wide 6
range of experiments and code development to gain more insights 7
and understandings into those phenomena and processes.
8 Some examples of severe accident phenomena and 9
technical areas that the severe accident research program has 10 examined include fission product release, transport, deposition 11 and revaporization, both in the primary system and in the 12 containment, co;stainment loadings, given severe accidents.
We i
13 looked at the hydrogen phenomena involving both burning, 14 conflagration, or detonations.
We looked at, given a massive 15 core melt that penetrates the vessel, and if it attacks the 16 concrete basement, we looked at the mechanisms of core-17 concrete interactions, and the gases, and the forces that are 18 generated as a result of those interactions.
19 We tested the containments themselves to see what is 20 their capability.
At this point, I would like to say that most j
1 21 of our, all of our containments of course have been designed
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22 for the so-called design basis accidents.
The large break LOCA 23 or steamline breaks.
But, because of the conservatisms in the 24 codes that have been utilized to design them, most or I would 25 say all of our containments have ample margin to go beyond the
24 1
original design basis.
In fact, they're able to withstand a 2
large number of severe accident scenarios.
Not of course, the 3
complete spectrum.
There are always some extreme low-4 likelihood scenarios that can challenge the containment. But I 5
think it's important to stress at this point that our 6
containments are able to accommodate forces, pressures, and 7
temperatures that go beyond the original design basis.
In 8
fact, one of the objectives of the accident management program 9
is to understand those margins and be able to utilize them in 10 an accident management strategy.
We also looked at the effect 11 of natural circulation on the primary system.
So these are 12 some of the basic things that we did over the past few years.
13 The primary emphasis in the near future will be to 14 resolve specific technical issues associated with the main 15 elements of the plan to facilitate the formulation of staff 16 positions, especially in the area of core containment i
17 performance improvement.
And I have listed some of the 18 specific issues that I'm talking about here.
For example, 19 meltspreading and potential containment or shell failure in 20 Mark I's.
The containment failure probability by the rad 21 containment heating.
Resource data and models to assess 22 accident management strategies.
23 For the longer term, I will be pursuing confirmatory 24 research on issues such as refining hydrogen behavior models, 25 core melt progression, a look at the later stages, some
25 1
additional work on core-concrete interactions, especially with 2
corium, that is reaching metallic components.
And to pursue 3
further model assessment and refinements.
Again the main point 4
in the next few years, the research program will emphasize i
5 resolving specific issues.
Not dwell in the abstract.
An 6
example of that is given on page 11, Mr. Chairman.
7 CHAIRMAN ZECH:
Before you go on.
Let me just ask 8
you in that regard.
It would appear that there -- some of 9
these confirmatory research projects ere extremely important, 10 and of course, have not been resolved as of now.
That's why 11 you need further research on them.
But I guess my question 12 would be, looking at the time schedule for completion of the 13 IPE program, do you anticipate these research efforts will be 14 resolved sufficiently to make you, to allow you to a confident 15 recommendation regarding IPE program itself.
16 MR. SPEIS:
Yes, we feel confident that we can i
17 integrate existing information, make decisions, and in some 18 areas, the decision process will be such that you will need 19 confirmatory.
But I think we'll be able to make decisions i
20 based on information that exists.
Many times you do make 21 decisions that you don't have all of the information in front 22 of you.
It's decisionmaking that involves uncertainties.
But 23 those uncertainties can be bound and we're pursuing strategies 24 that can at least for the time being put some of these 25 uncertainties on the side, and still implement some of these i
26 1
programs that will further reduce the residual risk that we're 2
talking about.
3 CHAIRMAN ZECH:
I'd encourage you to watch that very 4
carefully.
Because I think the Commission will be very 5
interested in ensuring the research program and the associated 6
data that's so necessary will be forthcoming in a timely manner 7
so that you can make these IPE decisions with confidence.
So, 8
as we proceed along that line, I think it would be important to 9
let us know what research has been completed and what 10 confidence you have that it is progressing in an appropriate 11 manner.
All right?
Thank you.
Proceed.
12 MR. SPEIS:
On page 11, I give an example of how 13 we're attempting to focus the research to address some of the 14 specific issues that you alluded to, Mr. Chairman.
I have 15 given an example here for a specific type of containment.
I 16 have described the associated issues and below I have 17 addressed, the research to address.
In the Commission paper 18 itself, we have attempted to focus the research program on the j
19 issues associated with both containment types, all containment 20 types, that are utilized in the United States.
21 Again, we have attempted to identify the issues.
22 Some of these issues have been discussed with industry, with 23 our research people at the laboratories, and again as I say, 24 our focus in the next few years is to focus, to address those 25 specific safety issues.
On page --
27 1
COMMISSIONER ROGERS:
Just before you leave that 2
page, could you just clarify a little bit on this matter of 3
cut-off pressure for HPE and the DCH issue.
I'm not quite 4
clear on what --
5 MR. SPEIS:
Yes.
What we're talking about here.
6 There is a mechanism that has been postulated where the vessel 7
will fail under high pressure conditions and the corium itself 8
will blow down into the containment, and in addition to the 9
thermal transfer of heat there will be chemical reactions that 10 will augment the pressure.
There we're talking about what is 11 that pressure level where this phenomenon is not important.
12 Okay?
And that's --
13 COMMISSIONER ROGERS:
A drop below this pressure.
14 MR. SPEIS:
Yes.
And that's what we're talking 15
- about, i
16 COMMISSIONER ROGERS:
Okay.
17 CHAIRMAN ZECH:
Let me make a comment on that too, 18 before you move along.
In the discussion in your paper on i
19 containment performance, I would -- I didn't see as much 20 discussion on prevention versus mitigation as I might expect.
21 I know you've thought about that.
But it seems to me as you go i
22 through the considerations of containment performance that you 23 continue to balance the prevention versus mitigation 24 considerations.
It's extremely important.
And if you're 25 giving a certain emphasis to prevention, for example, rather
28 1
than mitigation, in accordance with perhaps the consideration 2
of the safety goal or other considerations, those things should 3
be pointed out to us.
In other words, the rationale that you
~.
4 use in mitigation versus prevention-type thoughts, analysis, I 5
think would be helpful for the Commission to get as you present 6
these containment-performance considerations to us.
7 MR. STELLO:
Mr. Chairman, you will be getting 8
precisely that kind of thought process in the paper sometime in 9-June on the Mark I's.
10
, CHAIRMAN ZECH:
Fine.
That's what we'll be looking 11 for.
All right.
Thank you.
12 MR. SPEIS:
The next page, Mr. Chairman.
I'd like to 13 say something about the accident management program.
Dr.
14 Murley already mentioned the Commission paper that will be 15 coming to you on it.
We view the accident management as an 16 important means of possibly achieving a substantial reduction 17 in risk from severe accidents.
I would like to start a 18 presentation on this subject by saying that PRAs typically 19 measure the loss of adequate core cooling and not core melt.
20 Because since PRAs normally do not address in a substantive way 21 the likelihood of recovery actions.
So at present, there is no 22 good way to c.sr.tify the fraction of severe core damage 23 accidents thed m to core melt.
24 And when I'm talking about severe core damage 25 accidents, I'm talking about TMI.
Where TMI was a core damage m
-w y
,+
+ew-T
29 1
accident, but it was arrested.
And finally the corium was, 2
stayed inside the vessel and the vessel was perietrated.
So 3
when you see a number that comes from a PRA, it normally 4
measures the loss of core cooling and does not address the 5
number that is associated with the vessel melting.
okay.
So 6
to us, accident management is very important because we're 7
going to focus in that area to see even if an accident is 8
initiated and the initiation of a core degradation process 9
begins.
You know, what things can be done to make sure that 10 the accident is arrested.
And accident management will play an 11 important role in this area.
12 That's why I say it's a very important program.
And 13 we look at this as very important in reducing the risk of 14 severe accidents.
15 Now accident management includes the measures taken 16 by the plant cperating and technical staff to prevent core 17 damage and to us, preventing core damage is part of the severe 18 accident program itself.
Severe accident is not only.when a 19 severe accident takes place and proceeds to challenge the 20 containment, and that comes to your prevention. discussion that 21 you had previously with Mr. Stello.
22 As part of the accident management, we look at the 23 means to terminate the core damage if it occurs and retain the 24 core within the reactor vessel, as I said earlier.
And falling 25 that, maintain containment integrity as long as possible.
And
30 1
even failing that, to minimize the consequences of outside 2
releases.
So, it's a very integral process that we're looking 3
at.
Accident management encompasses hardware, human and
_ 4 organization factors, of course.
It provides decision-makers 5
at the plant a structured program for. managing a severe 6
accident.
So you have to have thought about this thing ahead 7
of time.
You have to put the procedures in place.
And last 8
tut not least, you have to train the operators and the 9
technical staff in the management of the plant to be prepared 10 to undertake such activities if the need ever arises.
11 Now in the proposed individual plant examination 12 generic letter, the way we addressed accident management is as 13 follows:
14 Utilities are expected to develop an accident 15 management program for prevention or mitigation of risk 16 important severe accident sequences.
We described that in 17 detail.
And identify measures that plant personnel can and 18 should take in case of severe accidents.
19 We're working with industry, with NUMARO to develop 20 an accident management framework.
We don't want to have a 21 separate accident management program for every plant.
I think 22 there should be some coordination.
But meanwhile, we're 23 telling utilities that, as you go through your individual plant 24 examination and you find some things that you think will 25 improve your plant in this area, you go ahead and take the g +
y 3
-,-m.---,w,=.n
,, - - +. - -
n
31 i
1 initiative and do it and just use the criteria 10 CFR 50.59 as i
2 part of that process.
i 3
This 10 CFR 50.59, it's something that the utilities 4
can take the initiative to do whatever they think is prudent as-5 long as it does not change the balance of the previously 6
analyzed safety of the plant.
7 So again, that is a brief summary of the accident 8
management program.
We'll be telling you more about it when we 9
come to you with the individual plant examination letter.
10 Next, I would like to discuss the role of the NUREG-
)
11 1150 as part of supporting our main line efforts in this area.
12 In February of '87, NRC published this reactor risk reference 13 document, NUREG-1150 in draft form for public comments.
It is 14 currently being revised to accommodate comments received as a 15 result of a number of peer reviews that it has received.
And 16 our present plans are to complete it by the end of this year.
17 COMMISSIONER ROBERTS:
It will be completed by when?
18 MR. SPEIS:
By the end of this year, Mr. Roberts.
19 December '88.
I have to look.
I saw Murphy in the back, who 20 is the guru of this, to make sure I said the right thing.
The 21 objective of this document has been to provide a snapshot of
~
22 the state-of-the-art PRA technology.
It basically incorporates 23 improvements in methods and data that have been accumulated 24 since the WASH-1400 document that was put together in the mid 25
'70s.
It includes examination of severe accident frequencies
32 1
and risks and their associated uncertainties for five specific 2
plants.
3 Its role in the regulatory process.
It has many of 4
them.
It's to provido independent staff assessment of risk.
5 It provides technical data on a number of issues and phenomeria 6
and integral studies to the individual plant examination.
It 7
provides insight to develop accident management strategies.
It 8
provides insights and calculations of containment performance 9
in each of these that you have underway.
Also it provides 10 insights in the areas of resolving a number of, generic issues.
11 Also, it's going to be utilized to prioritize, to 12 focus our resource activities, especially for the next few 13 years.
14
- Now, n".
Chairman, I would like to spend the 15 remaining of my time to discuss, say some more about severe 16 accident closure process itself and discuss some of its 17 elements.
This thing is described in some detail in the 18 Commission paper starting on page 18.
Basically, the severe 19 accident closure defines for the industry those programs which 20 are critical to resolving severe accident issues for their 21 plants and identifies the specific steps that must be taken to 22 achieve resolution.
23 Actions must be taken for generic issues and plant-24 specific issues.
Closure for generic issues results when the 25 Commission either takes action in the form of rulemakings or
33 1
explicitly states whatever its required approach is.
And 2
closure for plant-specific issues results when each utility has 3
completed certain evaluations and implemented certain programs 4
such that the events which comprise the dominant contributions 5
to risk are identified and practical improvements are made to 6
reduce the probability of risk contributors or their 7
consequences to acceptable low levels.
So, this is kind of an 8
overview.
9 I would like to summarize now the use of the safety 10 goal in the closure process.
This is only an outline.
And it 11 kind of provides the, again the outline of something that will 12 be coming to you, Mr. Chairman and Mr. Commissioners.
In 13 August, we will be providing you a very detailed paper that 14 recommends to you hou to go forward with implementing the 15 safety goal.
All elements of it, our plan is that the safety 16 goals and objectives will be used only for the resolution of 17 generic issues.
Resolution of plant-specific issues will be 18 accomplished through the IPEs, and the plant-specific backfit 19 criteria which are in existence.
20 Safety goal policy implementation plan will be 21 published, as I say in August
'88, and it will address the 22 Commission concerns and the ACRS recommendations.
We're 23 interacting with the ACRS very extensively in this area as you 24 recommended, Mr. Chairman.
And those concerns expressed by the 25 ACRS and the process of interaction will be described in this I
- - - - ~ -
34 1
Commission paper.
Basically all PRA information will be used 2
to make comparisons with applicable safety goal objectives.
3 We will determine why certain classes of plants don't 4
meet safety goal objectives and assess reasons relative to 5
current regulatory requirements.
Again, this is going in the 6
ACRS direction, when instead of comparing numbers with numbers, 7
we'll examine the regulations and the specifics in plants to 8
see in an engineering way why some plants don't meet safety 9
goal objectives.
Now such assessments will test the 10 effectiveness of the present requirements and may result in 11 changes to regulations on a generic basis and safety 12 enhancements.
13 Such safety enhancements, of course, will be subject 14 to regulatory analysis per the Commission's backfit rule, and 15 proposed to the Commission for backfit in the form of 16 rulemaking.
We will go forward in some of these areas.
The 17 first application will be reflected in staff recommendations to 18 Commission on BWR Mark I containments.
Performance 19 improvements which will be coming to you in the Fall of
'88.
i 20 The last capsule on this viewgraph is the thing that i
1 21 Mr. Stello brought to your attention, Mr. Chairman, the l
22 appropriate -- if appropriate, any proposed plant operational 23 improvements which cannot be justified by the backfit would be 24 provided to the Commission on a case-by-case basis.
25 COMMISSIONED ROBERTS:
I still have to ask, if
35
-1 improvements don't result in substantial safety benefits and 2
are not cost-beneficial, why would the staff propose them?
3 MR. SPEIS:
Well, as I said earlier, Mr.
4 Commissioner, in your policy statement, you talked about 5
balance between pravention and mitigation, for example.
Okay.
6 And it's possible in attempting to get to that balance, we 7
might find out that we're outside the balance of the backfit 8
policy.
Or -- and then for that case, if we find out that 9
there's some good reason to do something, we'll come to you.
10 Again, we take that guidance from that broad statement in the 11 Commission policy statement.
12 Another example is in the implementation of the 13 safety goal.
The 10 minus 6 large release, the way that is 14 defined, the way that you people will tell us what is the 15 appropriate way to proceed might be outside the bounda of 16 backfit policy.
And in that situation, then we'll come to you 17 on that.
So these are two specific examples that it's possible 18 we might find ourselves.
But again, the bottom line would be 19 safety and if we find out that we do things that don't improve 20 safety, I don't think we as a staff will come to you.
21 MR. STELLO:
I think if it isn't a significant safety 22 improvement, we certainly aren't going to come.
But whether or 23 not when you strip into a cost benefit analysis you can reach 24 to some of the other policy, tn 10 to the minus 6 and the 25 safety goal, or the balance in the philosophy and the policy of
36 i
)
1 the Commission for severe accidents.
We needed to have, if you
)
2 will, an escape valve, and since we're not sure we know how to 3
draw every line for every issue and that the backfit rule in i
4 every case is as far as the Commission would want us to gd.
If 5
there's a question, we're going to come to the Commission.
As 6
long as that philosophy, the backfit rule itself, allows us to 7
continue, we're going to go.
But whenever there's a problem, 8
we're going to come back to the Commission on a case-by-case 9
basis for you to give us further direction.
That's simply what 10 it means.
11 CHAIRMAN ZECH:
And I think that's very important 12 myself.
Because I believe when there is any doubt at all, and 13 recognizing that we're making judgments, engineering, 14 scientific judgments, that aren't always quantifiable with a 15 fine line, I think it's very important in those cases that 16 staff does come to the Commission to either affirm or reject 17 the staff's recommendation.
I think that's very important and 18 I think it's part of my understanding that the backfit rule 19 does not prevent the Commission in any way from making a 20 decision, if we, the Commission, do believe that safety can and 21 should be improved.
So I think those are the ones we are
)
22 talking about.
Those judgments should come to the Commission.
23 The backfit rule should not preclude you from worrying greatly 24 about how the balance flows between the cost benefit analysis.
25 If you believe there's a doubt or judgments involved, I think
)
37 1
it's the Commission's responsibility to make those decisions.
j 2
MR. STELLO:
We agree with that.
l 3
MR. SPEIS:
On page 16, Mr. Chairman, I say something 4
about the resolution of plant-unique issues.
I alluded to it l
5 earlier.
In' performing the individual plant examinations, our 6
utilities may find and it is expected that they will 7
voluntarily remedy any uncovered outliers, and make any 8
improvements they deem appropriate, conforming however, to 10 9
CFR 50.59.
However, through the review of the individual plant 10 examination submittals, if the staff finds on a plant 11 individual basis areas that can -- that the staff thinks 12 improvements should be pursued, then we have to exercise the 13 backfit rule in that case.
14 MR. STELLO:
Incidentally, with respect to the first 15 issue, we have found that the utilities are in fact doing 16 exactly what that says.
As we've gone through with NUREG-1150, 17 and in the process of doing an analysis, if an issue came up 18 which suggests that there were things that could be done to 19 solve a problem, the utility is moving forward expeditiously, 20 making those changes themselves, putting in procedures.
And 21 the response of the utilities with respect to this kind of an 22 effort seems to be very, very positive.
So I put a lot of 23 emphasis on that.
I'm not so sure we're going to have very 24 much of a problem.
But wait and see.
Based on what we see 25 now, it looks good.
1 i
,- -,-- ~. - -.. - -. - - - --,- --- --.- -,
i I
38 1
COMMISSIONER CARR:
The second item says we're going 2
to review all IPEs, and as I read it, they're going to be 3
through in three years.
How long is it going to take us to 4
review them?
l 5
MR. SPIES:
I have it someplace.
No more than two 6
years.
7 COMMISSIONER CARR:
So it's five years total, 8
probably.
9 MR. SPIES:
Yes.
On page 16, Mr. Chairman -- I'm 10 sorry -- on page 17, I again summarize the closure process.
I 11 said at the beginning and I will say it again, in summary 12 fashion, the steps which each utility is expected to take to 13 achieve closure of the severe accident issues for its plants 14 are completion of the individual plant examination, 15 identification of potential improvements, evaluation and fix as 16 appropriate or if necessary, develop and implement a framework 17 for an accident management program that can accommodata new 18 information as it develops, if we gain more understanding about 19 how to improve the prevention or how to retain the core vessel 20 or how to do other things that will improve safety, then this 21 accident management program should be flexible enough to 22 accommodate those strategies, and implement any generic 23 requirements resulting from containment performance 24 improvement, which, as I said earlier, it's very closely 25 coupled to the'IPE program itself.
l
- - - - J
39 1
Severe accident research will continue to confirm 2
some of these judgment, and any new issues that arise in the 3
future will be handled on a case-by-case basis.
4 On Table 1 on page 18 --
5 CHAIRMAN ZECH:
Before you go to that, my review of 6
your paper would lead me to believe that the Staff has, indeed, 7
reasonably addressed the ACRS concerns and their suggestions 8
that the IPE program may be broadened and combined with the 9
ISAP program.
I think you have addressed that properly.
10 But I guess my question would bog do you think there 11 are some strong parts of the ISAP program which should be 12 picked up in the IPE program, or are you still looking at that?
13 MR. STELLO:
Well, the first part, I think, depends 14 on the utility.
I think the utility needs to make the 15 commitment to want to go to the ISAP program themselves.
I'm 16 not so sure I see how you can stop short of doing the full 17 process, which would be getting an integrated plan to make 18 these improvements.
So I think it really has to start with the 19 utility.
If they want to do it, and we can get the resources, 20 I think it's a good idea.
21 If I were a utility executive, that's what I'd want 4
22 to do.
23 CHAIRMAN ZECH:
But I think the Staff should monitor 24 that very carefully to make sure that we don't -- that we will 25 agree that the decisions they are making are the appropriate
40 1
ones, and if there's any doubt, then you should get more 2
heavily involved.
3 MR. STELLO:
Absolutely.
4 CHAIRMAN ZECH:
All right.
Please proceed.
5 MR. SPIES:
On the last page of the presentation, Mr.
6 Chairman, I have a table in which I tried to summarize the 7
individual pieces of information that will be reaching the 8
Commission and on which of these items a Commission decision 1
9 will be required.
Starting with the individual plant 10 examinations, the Commission paper will be reaching you in July 11 of
'88, and the Commission will be requested to approve the 12 issuance of the generic letter initiating the IPEs.
13 Likewise on containment performance improvements, BWR 14 MARK Is, we will be providing to you at the end of this month a 15 status paper.
We will be providing you our recommendations in 16 the fall of '88, and for that issue, also we expect you to make 17 a decision on our recommendations.
Likewise for the other 18 containment issues that will be coming to you by the end of 19 next year.
20 On Item 3 and 4, improved plant operations and severe 21 accident resource program, these are continuous efforts.
We 22 don't expect any actions on your part at this time.
23 on external events, we expect that you approve or you 24 make a decision on our recommendations.
25 On accident management, there is -- will be a paper
41 1
for information now only.
Tom, I missed if you said that there 2
will be a Commission decision at that time on the accident 3
management program.
I guess we'll have to see as we -- we 4
don't foresee it at this point in time, right?
5 NUREG-1150, no Commission decision is expected.
6 There will be a paper for information only.
Likewise for 7
Issues 8 and 9, the generic safety issues and the integrated 8
safety assessment program.
9 On advanced reactors, we will be coming to you.
10 There are two types of advanced reactors, the LWRs and the non-11 LWRs, the DOE reactors, the HTGRs and the liquid metal 12 reactors.
On both of them, we will be coming to you with 13 recommendations and expect you to make a decision on both of 14 these -- in both of these areas.
15 And last, the safety goal policy implementation, a l
16 very important area, the Commission paper will be coming to you 17 in August, and we would expect you to make a decision on our 18 recommendations.
19 With that, Mr. Chairman, I think my presentation --
i 20 I've completed my presentation.
21 CHAIRMAN ZECH:
Let me just make a comment or two on 22 this last table.
Firat of all, I expect that the Staff, as you 23 continue to revieu containment performance and severe accident 24 research and accident management and so forth and other generic 25 issues, that if, during the course of your review, you
42 1
determine that something is more significant perhaps than you 2
realize or something that should be done, you'll take action, 3
nr if you feel it should come to the commission, I wouldn't 4
want you to feel bound by the schedule.
5 In other words, if there is something that's safety 6
significant, we want to know about it right away.
7 And the other comment I'd like to make is that I 8
think that the schedule you've got, as near as we can tell, 9
certainly on these very significant issues, looks to be, at 10 least from my standpoint, reasonable, but in the column where 11 you have expected commission action as you go through and 12 determine perhaps that you may want to change your mind about 13 coming to the Commission, don't hesitate to come to the 14 Commission at any time on any of those issues that you really 15 think should come to the commission as you proceed.
16 We want to be involved.
If there's any doubt, come 17 to the Commission.
18 All right.
Is that --
19 MR. SPIES:
That completes my presentation, Mr.
20 Chairman.
21 CHAIRMAN ZECH:
Mr. Stello, any other comments?
~
22 MR. STELLO:
No.
23 CHAIRMAN ZECH:
Then comments from my fellow Commissioners.
Commissioner Roberts?
24 25 COMMISSIONER ROBERTS:
Well, I only want to say I
43 1
agree with what you said in your opening remarks about you 2
think the backfit rule is working and working well, and I agree 3
with that, and I think it's good policy.
And I think the 4
backfit rule gives appropriate and adequate guidance to the 5
Staff in making decisions on proposals for planned 6
improvements.
That's all I have to say.
7 CHAIRMAN ZECH:
All right.
Thank you.
Commissioner 8
Carr?
9 COMMISSIONER CARR:
Yes, I have some comments on the 10 accident management plan, and I'm a little curious as to what's 11 going to be the definition of a satisfactory severe accident 12 management framework that you're expecting the utilities to 13 come in with.
What are we talking about?
14 MR. SPIES:
Mr. Commissioner, this is something we're 15 discussing with the industry right now, and let me tell you 16 what I meant by it.
You know, we have the emergency operating 17 procedures in place that you are very familiar with, so what we 18 are talking about -- by the way, they go up to some point in
~
19 these scenarios, like inadequate core cooling, even though for 20 BWRs they go beyond into the venting area -- we're talking 21 about, should we add, when we go beyond, to prevent core melt -
22
- I mean, to contain core melt in the vessel or structure 23 strategies to reduce its threat to the cor.tainment, are we 24 going to put those procedures --
1 25 COMMISSIONER CARR:
I understand that.
44 1
MR. SPIES:
Together with the EOPs.
Are we going to 2
have them separately?
Lots of things we are talking about.
3 COMMISSIONER CARR:
I understand that part of it, but 4
I'm a little curious about how they're going to close.
You 5
said one of the things they have to do for closure is to 6
develop and implement a framework for an accident management 7
program.
8 MR. SPIES:
To commit.
To commit to do an accident -
9
- to have an accident management program.
That goes beyond the 10 existing --
11 COMMISSIONER CARR:
It says develop and implement.
12 MR. STELLO:
Let me try.
13 MR. SPIES:
The framework is being developed now.
14 MR. STELLO:
Let me try again.
The procedures 15 obviously have to be developed after you do the IPE, find out 16 what the particular improvements are that can be made, what 17 procedures ought to be implemented, and then go on and develop 18 and implement them.
I think that's what it says simply.
19 I'd use an easier example, I think, to understand.
20 Direct heating at the containment, high-pressure injection of 21 the corium.
There are ways in which you can significantly 22 change the course of that accident perhaps by opening the 23 relief valves earlier in the transient, and that would be a 24 severe accident procedure.
25 COMMISSIONER CARR:
Which is going to depend on some
45 1
research.
2 MR. STELLO:
Well, that work is ongoing right now, 3
which we will have finished in time for them to make that 4
judguent on the management.
5 COKMISSIONER CARR:
I'm glad to hear you say that.
I 6
wish I had that same confidence.
7 MR. STFLLO:
I'm confident.
8 COMMISSIONER CARR:
All right.
Well, it seems to me 9
that area is a little fuzzy, and maybe that's what you intended 10 it to be, since we don't really know what we're going to 11 require yet.
12 Okay.
The other thing I'd like to recommend is, 13 since you were mentioning that the generic le't.ter on IPEs is 14 going to formalize the Commission's approach to accident 15 management, I'd like to see that accident management program 16 plan paper before we approve the IPE letter, or I'd like to get 17 in on that act somewhere, because it's going to a piece of 18 something, and I don't know what we're saying.
19 So could you send those in at the same time?
Can you 20 separate the two?
21 MR. STELLO:
I would prefer to have the Commission
~
22 approve the accident management program, and we'll send that up 23 for the commission's approval to make sure it's okay.
We're 24 fairly e?ose to having --
25 COMMISSIONER CARR:
Well, one says July, and the
, -, - - + _ _ _..,.
46 1
other one says fall.
I don't know how close those things --
2 MR. STELLO:
Well, the one that says July is --
3 COMMISSIONER CARR:
One says July, and one says fall.
1 4
MR. STELLO:
You got it.
5 MR. SPIES:
There will be enough information in the 6
IPE packet and accident management that hopefully it will 7
satisfy you, Mr. Commissioner.
8 MR. STELLO:
But if not, we would prefer to make the 9
commitment to bring that up and have commission approval at 10 that point.
11 COMMISSIONER CARR:
Well, you can see my problem.
12 MR. STELLO:
Yes.
13 COMMISSIONER CARR:
The other area, severe accident 14 training, management training, I want to be sure we don't 15 overblow that issue, you know.
Most of the problems we've got 16 come from training that leads to the severe accident or lack 17 thereof.
It's like teaching all drivers to be defensive 18 drivers or handle quick reversals in their cars.
We hope they 19 never have to do that, but it's a handy thing to know once, but 20 you don't have to train on it a lot and a long time.
21 I don't want to focus these people on managing severe 1
i 22 accidents at the expense of running their plants day to day.
23 MR. STELLO:
Absolutely.
24 COMMISSIONER CARR:
They don't get enough practice in 25 starting up and shutting down, in my opinion, because they are
-- l
47 1
designed to run X number of days without any problem.
And so 2
we don't want to overemphasize how much training we put on that 3
area.
4 MR. SPIES:
We agree fully with that.
In fact, 5
that's one of the things we are discussing with the industry.
6 We're in total agreement with that.
7 CHAIRMAN ZECH:
Anything else, commissioner Carr?
8 COMMISSIONER CARR:
No.
I just -- do you think that 9
schedule you've got there is reasonable, and you're going to 10 make it?
11 MR. SPIES:
Yes, yes.
Most of this work --
12 COMMISSIONER CARR:
I'll watch with interest.
Thank 13 you.
14 CHAIRMAN ZECH:
Commissioner Rogers?
15 COMMISSIONER ROGERS:
Well, I just want to say that I 16 found this whole document a very interesting and comprehensive 17 piece of work.
There are a number of questions about details, 18 how they will actually be carried out.
But the attempt to 19 bring this all together into what you would define to be i
20 closure, namely to close the loop, that you've gone through the 21 whole cycle on this, I thought was an excellent approach, and I 22 really want to commend the Staff for the clearly enormous 23 effort of thought that has been required to bring it to this 4
24 point.
I think it really is very commendable.
25 I do have a number of little questions about things
48 1
along the way.
Some of them have already been touched on.
But 2
if you would bear with me for a moment, I could perhaps try to 3
go through my little liet of questions quickly.
4 The Slide 4, Severe Accident Activities, it wasn't 5
clear to me how you're going to effect closure between the 6
efforts of the individual licensee in carrying out an IPE and 7
the results that will be' coming out of analysis or research 8
activities that relate to containment performance and accident 9
management and generic issues, how you get that back into the 10 work of the licensee as those things proceed during the three-11 year period during which the licensee is developing the IPE.
12 So it wasn't clear to me just how that feedback 13 mechanism or information flow or what your system is to get 14 that out to individual licensees as they are proceeding with 15 the development of their IPE.
I wonder if you could just say a 16 little bit about that?
17 Do you have a clear mechanism in place or in mind?
18 MR. MURLEY:
Maybe I could take a cut at that.
19 Closure as envisioned in this document and this chart is really 20 a process.
It's not going to be a package, let's say, that we 21 come in with on each plant, so that --
22 COMMISSIONER ROGERS:
No, I understand.
23 MR. MURLEY:
Okay.
What it envisions is that we will
)
24 have addressed the major issues still open in severe accidents 25 for each plant.
This is meant to portray what those issues 1
49 1
are, and it's also contemplated that each plant will be 2
different in terms of its vulnerability to severe accidents, so 3
that, let's say, some MARK I plants may not have to do 4
anything.
Others may have to make some changes.
Likewise with 1
5 accident management.
6 Our intention would be that as we come to a 7
resolution with the Commission of what's required to address 8
the MARK I issue, for example, we would use the regulatory 9
tools that we he.ve, like generic letters or that sort of thing, 10 to implement any additional requirements.
So this program --
1 11 I'm not sure I'm getting at exactly your question, but this 12 program envisions that over the next few years, there would be 13 several regulatory requirements type documents that may go out.
14 Each plant would be more or less susceptible to those, 15 depending on how it relates to the issue that ;'a're dealing 16 with.
17 COMMISSIONER ROGERS:
Well, I was just thinking of, 18 you know, some way of providing ongoing communication with 19 licensees as they are proceeding through the development of 20 their IPEn as to the state of affairs of any issue that might 21 be coming close to resolution that will affect their completion 22 of their IPE.
You know, it's kind of an intermediate feedback i
23 mechanism that is there.
24 MR. STELLO:
NUMARC has organized itself to be able 25 to interact in this area, and should that come to pass, that 1
50 1
will be the easiest and most direct way of having the results 2
of research communicated to them and then in turn passed on.
3 COMMISSIONER ROGERS:
I'm just concerned about 4
someone essentially completing an IPE or being, you know, 5
within six months of completing a three-year effort, and then 6
all of a sudden there's a new finding that's coming out that 7
now has to be accommodated in their plant, that if they were 8
aware of, they could have rescheduled their efforts to 9
accommodate more easily.
10 MR. STELLO:
We hope that the industry will organize 11 itself to do that, and if they do, that will be the easiest and 12 most direct way.
Otherwise, we will develop some mechanism of 13 communicating the research results directly ourselves.
I think 14 it would be better for the industry if it did organize itself 15 to be able to assimilate that kind of information and then 16 reduce it to useful packages for the --
17 COMMISSIONER ROGERS:
Well, presumably our efforts 18 have to be easily accessible to that kind of --
19 MR. STELLO:
Oh, we will definitely make that the 20 case, make sure that happens.
21 COMMISSIONER ROGERS:
In the full report, not your 22 summary of it, Mr. Stello, but in the full report that we 23 received, on page 15, in the reference to the ACRS' comments 24 and your answers to those, there was a little point that 25 bothered me a bit in an answer there.
You say in reference to
1 51 1
the IPE generic letter, the letter states that if a utility 2
concludes through the IPE and proposes to the Staff that --
3 one, two or three -- Item 2 is, there is not shown to be a 4
cost-effective resolution to the issue, the Staff will consider 5
the issue resolved upon review and acceptance of the IPE 6
results.
7 That left some questions in my mind.
This is page 15 8
of the full report, not Mr. Stello's comprehensive summary.
9 Just really what you had in mind there, because it 10 looks as if that might just be -- that implied that if there 11 isn't a cost-effective resolution to an issue, that it might 12 somehow or other just get dropped.
13 I know that it doesn't necessarily say that, but are 14 you following the --
15 MR. SPIES:
Yes, I follow your --
16 COMMISSIONER ROGERS:
And I'm just a little concerned 17 about how you propose to deal with that, what that really 18 means.
19 MR. SPIES:
Well, here we're talking about a specific 20 issue for a specific plant, and we're talking about Itens 1, 2,
i 21 and 3.
They can go ahead and give us the information.
They 22 can go ahead and do the regulatory -- we have to pass judgment 23 on that, okay?
And that doesn't mean that, you know -- this 24 implies that we will have reviewed that, and if we accept it, 25 fine.
If not, then we'll have to go through it farther.
It j
i
52 1
doesn't imply that.we'll accept it at face value and write it 2
off without reviewing their submittals.
That's all it means.
3 MR. STELLO:
I think in simple terms, the utility 4
can, when they do their IPE program show that certain USIs and 5
GSIs really don't apply to them, based on their unique 6
situation, and find a way to close that issue on that plant at 7
that time.
8 COMMI!SIONER ROGERS:
I'm worried about the "no cost-9 effective resolution," Item 2.
10 MR. STELLO:
Yes.
11 COMMISSIONER ROGERS:
Well, if they feel there's no 12 cost-effective resolution of the issue, then how do we deal 13 with that?
14 MR. SPIES:
Well, we'll review it ourselves.
We have 15 a normal review process, and we'll either accept or reject.
So 16 that's the way it was meant anyhow.
17 MR. STELLO:
The presumption is, we'll agree.
If we 18 don't agree, that may be one of the issues we'll bring to the 19 Commission, if the utility proposed to do it that way, and 20 we'll bring up to the Commission.
21 COMMISSIONER CARR:
I have a little problem on that
'~
22 same page further down when you're talking about deterministic 23 methods such as those being developed under the seismic design 24 margin program, which may be just as effective in identifying 25 vulnerabilities at a lower cost.
I didn't understand that at
53 1
all.
2 MR. MURLEY:
What is meant just to be sure that the 3
lower cost is -- rather than doing a full PRA that includes all 4
the latest seismic margins technology, there are some simpler 5
methods that have been developed that we think can get -- can 6
be just as effective.
7 COMMISSIONER CARR:
It's only in the seismic area.
8 or there are a lot of areas like that?
9 MR. STELLO:
No.
No.
We have several seismic 10 programs that have been ongoing end have developed particular 11 methods to assess the seismic capability of the facility.
And 12 it's in that context, saying -- those methods have --
13 COMMISSIONER CARR:
You imply that those 14 deterministic methods may extend across a further area than 15 seismic.
16 MR. STELLO:
No.
It was limited with respect to the 17 issue of the seismic program that's been underway.
18 COMMISSIONER CARR:
All right.
19 COMMISSIONER ROGERS:
I just come back to page 9 of 20 your slides, the improved plant operations area.
Jast a 21 comment, really, on your effort to improve technical 22 specifications.
I think that's a very important activity.
23 It's one that I've been talking about the need to try to i
24 simplify, and weed out, and prune those things which really are 25 not, which happen to be there historically, but are really not
54 1
necessary.
Can you give me some idea of just what your level 2
of effort will be in carrying out that part of the activity?
3 How many people?
How serious are you about that?
4 MR. MURLEY:
Well, we're very serious about it.
It's 5
an ongoing program.
I'd say we're probably two-thirds of the 6
way through it now.
We've sent out for owner's group comments, 7
a document that proposes, which we've been working with -- this 8
document proposes what can be left in the textbacks, what's 9
important to safety, and what can be removed.
And as a rough 10 rule of thumb, it looks like, if these turn out to be accepted, 11 and the staff goes along with it, it can remove, cut down on 12 the number of LCL action statements by 40 percent, for example.
13 We have a branch that is, really one section of a 14 branch, that's devoted full-time to carrying this out.
My 15 guess is it's probably 4 or S FTEs.
So it is a substantial 16 effort on the part of staff, and as I said, I think we're 17 clearly, I can cee the end is in sight.
18 COMMISSIONER CARR:
Like when, do you think?
19 MR. MURLEY:
I'd have to --
i 20 COMMISSIONER CARR:
You've got farther vision than I 21 have.
22 MR. MURLEY:
It's a matter of like a year or two, 23 rather than five, or six, as envisioned in this document here.
24 COMMISSIONER ROGERS:
Also on that list, research to 25 establish the sensitivity of risk to human errors, do you have
55 1
a common view within the staff and various areas, research, and 2
NRR for example, of how to explicity take into account human 3
factors probabilities into PRAs.
Do you have a common view of 4
that, or is it some -- this is a controversial --
5 MR. MURLEY:
I can give you my --
6 COMMISSIONER ROGERS:
This is a controversial area.
7 COMMISSIONER CARRt It was a little open in the human o
8 factors research program.
9 MR. MURLEY:
I think that the models that we have 10 today, in fact, are not adequate for us to determine the effect 11 of recovery actions, just in one instance.
Themmy mentioned 12 that.
And as a result, the PRAs don't give us the full benefit 13 of improving human performance, because the models just don't 14 allow it.
Once the reactot reaches a certain state, in terms 15 of emergency cooling pumps not working and the core starting to 16 heat up, the models -- at least the older ones -- generally 17 assume that goes directly to core melt.
And we all know that 18 there's many things that the operators can do at that stage.
19 We don't have the models to actively quantify that.
20 A second area that I think we can work on is how to i
21 better estimate plant-specific human error rates.
Generally, 4
22 PRAs that are done today use a standard human error rate data.
23 It's taken from a handbook that was developed some years ago, I 24 believe for Air Force officers.
It's meant to apply across the 25 board, but in fact, every day we see wide variations from plant
i 56 1
to plant in human error rates.
And that, I think, forms part 2
of my reservations about using safety goals for plant-specific 3
decisions.
I think they're quite okay to use PRAs for a broad l
4 range of plants, to judge against safety goals.
But when you 5
get down to a specific plant, where the variation in human 6
error can be substantially different from the average, we don't 7
have the means for putting that into our models today.
8 COMMISSIONER ROGERS:
Do you think there's some 9
possibility of carrying that out?
l 10 MR. MURLEY:
Well, I've asked that Research continue 11 to develop these te.7hniques and I believe they're doing it.
So 12 let me turn to Themmy on that.
13 Joe, do you want to say something?
14 CHAIRMAN ZECH:
Yes, would you come to the 35 microphone, please, and identify yourself for the reporter.
16 MR. MURPHY:
Joe Murphy from the Office of Research.
l 17 I agree with what Dr. Murley has said.
We have 18 programs in place now that are going forward.
The techniques
)
19 in the more modern PRAs are the ones done in the last or a or i
20 two years.
We are taking into consideration some of the 21 elements of difference in the nature of the procedures, the j
22 attitude of the operators; it's starting to be done, there's 23 still a long way to go.
24 I think what we've seen is that there's promise that 1
25 we can do this better.
We have work ongoing in the field of j
i i
i
57 1
cognitive errors that the operator misinterprets the i
4 2
information coming in to him.
Most of the earlier PRAs were on 3
the order of procedural errors.
The operator missed a step in 4
this procedure or did something wrong in doing it, rather than 5
that he misdiagnosed.
6 I think in th? next year or two, we'll start along 7
the line of being able to factor this in much better than we 8
have in the past.
And I think that with time, we'll have those 9
in, but I agree with Dr. Murley, right now, we don't adequately j
10 include things like the influence of pla.it management on 11 operator performance.
The PRAs essentially assume that the 12 operators are average, industry average operators.
13 MR. STELLO:
I would want to emphasize while that 14 those are important for the longer-term average, I think there 1
]
15 are some short-term gains that we can make that vill be 16 important to safety.
And that's in the area of looking at the i
1
]
17 LER data, the cost codes, what really, underlying reasons, l
r 18 whether it was poor training, poor procedures, or maintenance, i
19 or surveillance and testing, that perhaps should never even 1
i 20 have been done during operation that caused the plant to be
)
21 subjected to unnecessary trips and equipment failures.
I think l
22 understanding the human element in that context, which I got
[
23 the thrust was one of the major comments from the briefing from l
j 24 the Academy that the commission had the other day.
I think i
1 25 thete we can probably do a great deal.
f i
58 1
And there are significant differences, as you look 2
. country to country.
For example, Japan and the United States.
3 The
" 1er of challenges to the plant which is a direct 4
co if you will, to risk, I think can be significantly 5
re, c simply by being a little bit more careful about 6
what
..le do.
7 COMMISSIONER ROGERS:
Well, the point I was trying to 8
get at was the quantification of these human factors in a PRA, 9
wnether, you know, there can be some way to -- with common 10 agreement as to how to include that, because once you do that, 11 then the PRA becomes a dynamic measure that can be looked at.
12 It becomes en index in itself that changes.
It's not just a 13 number that happens to be calculated at a certain point in time 14 for a plant and then goes up on a shelf and there it is 15 forever.
But is a dynamical measure of interest to us all.
16 And I think that's something that's well to keep in mind.
I 17 recognize that it has certain tricky elements to it, but it is 18 something that once one has a commonly-agreed upon methodology 19 for including human factors in the PRA, then the PRA takes on a 20 new significance --
21 KR. STELLO:
I agree.
22 COMMISSIONER ROGERS:
-- a new dynamical 23 significance.
I'll -- just one or two more things and I'll --
24 COMMISSIONER CARR:
I'll piggyback on that a second.
25 I think we'll get a lot of data out of that so-called research
l 59 l
1 and assimilator programs where we permit operators to take 2
actions that either prevent or mitigate the accident, and give 3
them credit for that.
If they do it wrong, we don't really go 4
that far and we don't let them take the action because it never 5
works and because otherwise you don't have a drill.
But I 6
think we can get some data in those areas.
7 COMMISSIONER ROGERS:
And coming to NUREG-1150, on 8
page 13, you cite that.
And just to bring us up to date on 9
what your thinking is with respect to direct comparison between 10 the technology or techniques of NUREG-1150 and the analysis of 11 WASH-1400, with respect to those two specific plants, Peach 12 Bottom and Surrey, it would be very nice to be abl9 to have 13 those direct comparisons of the new technology under NUREG-1150 14 applied to those same situations.
I know that you mentioned 15 that there have been improvements, but that was -- seemed to be 16 a somewhat qualitative statement with respect to changes in 17 those two plants based on NUREG-1150 rather than on the same 18 kind of analysis that was carried out for the five plants to be j
19 carried out in comparison with the results of WASH-1400 for 20 those two plants.
21 MR. STELLO:
We will have those comparisons directly
~
22 in NUREG-1150.
Yes, they will be.
23 COMMISSIONER ROGERS:
Under the full methodology.
I 24 see.
All right.
Because that was the question.
25 MR. SPEIS:
At least the most importan ones.
The
~
. ~.
60 1
ones that really make the difference, between then and now.
2 That would involve --
3 COMMISSIONER ROGERS:
Because I think that's very 4
interesting.
- improvements in data, improvements in 5
MR. SPEIS:
6 methodology, or whatever, you know, made the difference between 7
then and now.
8 COMMISSIONER ROGERS:
Do you expect to have any 9
additional external review of the revised version of 1150?
10 MR. STELLO:
My view at the moment is that we need to 11 get the document out and be able to use it.
And we've had 12 extensive review of that document.
Eric Beckjord has a meeting 13 scheduled later this month, to revisit that issue with some 14 people from the Academy and to discuss it further.
We have not 15 made a final decision, but I lean very heavy to let's finalize 16 it, put it out.
I think it's the kind of a document that 17 you're going to update again in a few years.
There's a lot of 18 activity that's going on and I think we have just got to find a 19 time to say, This is enough, Let's get it out and use it for 20 the purposes we can,"
and stop.
That's my view at the moment.
21 But we're still looking at it.
1 22 COMMISSIONER ROGERS:
Well, with so much leerned from 23 the exposure of the document to comment around the world that 24 in incorporating that all into a new document, there's still --
25 it will be a new document.
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61 1
MR. STELLO:
Agreed.
2 COMMISSIONER ROGERS:
And --
3 MR. STELLO:
But if we continue the cycle, we're
~
4 never going to get anything on the street that we can really 5
use, so I think --
6 COMMISSIONER ROGERS:
It's a decision that has to be 7
made.
8 MR. STELLO:
I think my inclination would be to just 9
get it on the street and of course, further comments, further 10 review would be desired and be used to help us guide in the 11 next time we visit this issue, which is clearly going to be in 12 several more years.
But we're already several years into 13 trying to get this version out.
We just have to stop at some 14 point.
15 COMMISSIONER ROGERS:
Just one final one.
On your 16 table lat the end of, in the schedule, page 18, slide 18.
The 17 integrated safety assessment program, you didn't expect to 18 bring that to the Commission.
I think that's something that 19 conceivably might have elements that the Commis31on would like 20 to respond to.
It has -- it's not quite as comprehensive as 21 the IPEs, I guess, but it would seem to me that there might be 22 some issues there that commission action might be called for.
23 That's item 9.
24 MR. STELLO:
Okay.
Well, it will be coming to the 25 Commission, because the way we presented it in the paper that
62 1
you have before you, what we have said is that we are making 2
the ISAP a program if utilities wish to come forward, our view 1
3 is that to the extent we can have the resources, we'd like to 4
do that.
And we have not concluded or suggested that it ought i
5 to be made mandatory.
In fact, we have recommended against 6
making it a mandatory program.
7 COMMISSIONER ROGERS:
Well, I just want to thank the 8
staff for an excellent presentation.
I found it very 9
informative.
Very helpful.
10 CHAIRMAN ZECH:
But again, you are going to send that 11 ISAP paper to me.
I think you say that.
And we will have it 12 for action as we see fit.
13 MR. STELLO:
Right.
14 CHAIRMAN ZdCH:
Well, let me just say --
Are there 15 any other comments, my fellow Commissioners?
Let me just say, 16 I, too, compliment the staff on a very important and difficult 17 task of bringing together all of these various programs and 18 policies.
What we're trying to do is build a structure, an 19 integrated structure, out of the various pieces we have.
And I 20 think that's extremely important.
Because we must put, in my 21 judgment, consistency, predictability, common sense, and 22 analytical credibility into the structure that we're building.
23 The pieces should fit together.
We recognize that they overlap 24 in some areas.
There are judgments to be made.
But I think 25 the effort to bring it together is going to be extremely
63 l
l 1
helpful to our entire regulatory process, and to public health j
2 and safety, and to our decisions in that regard.
So.I, too, 3
compliment the staff on an extremely difficult task.
4 But, Mr. Stello, you remember we talked about this 5
some time ago.
I've felt, and I know my colleagues have agreed
)
6 that the effort to bring these various programs together.in 7
some kind of a unified structure will enable us to make, the 8
staff to make better recommendations, the commission to make 9
better decisions.
So it's an extremely important endeavor.
10 And none of us belittle the inability perhaps to get more exact 11 judgments than you've come up with.
I think you've done an 12 outstanding job of trying to pull together these policy
)
13 statements.
14 But the action itself, the effort itself, I think is 15 extremely important.
The results, of course, are terribly 16 important, too.
But the effort you've made to pull together, 17 I'm sure, has made you question and look at some of the 18 overlapping areas that will cause further analysis, perhaps.
19 But in any case, I think you've done an excellent job, and I 20 commend the sta f f for that.
21 My only last point would be to emphasize what I've l
22 said before and what others have said, too, and I think you 23 sensed the Commission's desire to be very much involved in this 24 process.
And whenever there's any doubt in your mind -- these 25 are important policy matters -- that they should be brought to
l 64 1
the Commission's attention.
So I'd like to make that that last 2
emphasis that we do feel that these matters we're discussing 3
have tremendous impact on public health and safety, in the 4
broad sense, and will be watched very closely, I'm sure, by 5
other nations that we should make as good a decision on these 6
matters as we possibly can.
And so we do feel the commission 7
should be involved, and if thero's any doubt in your mind at
)
8 all about this, come to us for guidance, either informally or 9
formally, and we want to keep involved in the whole process as 10 it proceeds.
11 Again, let me compliment the staff on an excellent 12 job, and let's continue working closely with the Commission in l
1 13 this regard.
14 No other comments?
We stand adjourned.
Thank you 15 very much.
16 (Whereupon, at 11:35 a.m.,
the proceedings were 17 adjourned.)
18 i
19 20 21 22 23 24 25
4 CERTIFICATE OF TRANSCRIBER This is to certify that the attached events of a meeting of the U.S. Nuclear Regulatory Commission entitled:
TITLE OF MEETING: BRIEFING-ON SEVERE ACCIDENT INTEGRATION P:.AN PLACE OF MEETING:
Washington, D.C.
DATE OF MEETING:
THURSOAY, JUNE 2, 1988 i
were transcribed by me.
I further certify that said transcription is accurate and complete, to the best i
of my ability, and that the transcript is a true and j
accurate record of the foregoing events.
/
/_(i M.A V N..
- 't.,
r
}
I i-Ann Riley & Associates, Ltd.
e 9
COMMISSION BRIEFING ON SEVERE ACCIDENT INTEGRATION PLAN THEMIS P. SPEIS (301) 492-3710 0FFICE OF RESEARCli U. S. NUCLEAR REGULATORY COMMISSION JUNE 2, 1988 i
~.
4 BACKGROUND o
AUGUST 8, 1985, "SEVERE ACCIDENT POLICY STATEMENT,"
FEBRUARY 28, 1986, "IMPLEMENTATION PLAN FOR SEVERE ACCIDENT POLICY STATEMENT," SECY-86-76 o
DECEMBER 1, 1986, STAFF REQUIREMENTS MEMO, COMMISSION REQUESTED PAPER ON INTEGRATION OF SEVERE ACCIDENT ISSUES o
FEBRUARY 17, 1987, MEMO FROM ED0 TO COMMISSIONERS ON PRELIMINARY PLAN FOR INTEGRATION OF SEVERE ACCIDENT ISSUES o
JULY 15, 1987, STAFF BRIEFED COMMISSION ON A PLAN FOR CLOSURE OF SEVERE ACCIDENT ISSUES o
DECEMBER 8, 1987, "MARK I CONTAINMENT PERFORMANCE PROGRAM PLAN," SECY-87-297 o
FEBRUARY 9-11, 1988, BALTIMORE MANAGEMENT MEETING ON SEVERE ACCIDENT ISSUES 9
2
SEVERE ACCIDENT INTEGRATED PLAN o
PORPOSE:
TO PRESENT STAFF'S PLAN FOR INTEGRATION AND CLOSURE OF SEVERE ACCIDENT ISSUES o
OBJECTIVES:
TO PROVIDE AN UNDERSTANDING 0F THE STAFF ACTIVITIES THAT ARE UNDER WAY T0.
IMPLEMENT THE COMMISSION'S SEVERE ACCIDENT POLICY TO ASSURE THAT THESE ACTIVITIES ARE CONSISTENT WITH THE COMMISSION'S POLICY AND STRATEGIC G0ALS TO ASSURE THAT THE STAFF ACTIVITIES ARE CONSISTENT AMONG THEMSELVES, HAVE A COMMON G0AL 0F ULTIMATELY LEADING TO IMPROVED PLANT SAFETY, AND ARE PROPERLY COORDINATED AMONG THE RESPONSIBLE NRC ORGANIZATIONS TO ASSURE THAT THE COMMISSION IS AWARE OF THE KEY TECHNICAL AND POLICY ISSUES, SOME OF WHICH WILL NEED COMMISSION GUIDANCE OR APPROVAL TO DESCRIBE THE USE OF SAFETY G0ALS AND BACKFIT POLICY IN THE CLOSURE PROCESS l
3 l
i SEVERE ACCIDENT ACTIVITIES o
INDIVIDUAL PLANT EXAMINATIONS ilPE) o CONTAINMENT PERFORMANCE IMPROVEMENTS (CPI) o IMPROVED PLANT OPERATIONS (IPO)-
O SEVERE ACCIDENT RESEARCH PROGRAM (SARP) o ACCIDENT MANAGEMENT (AM) PROGRAM o
GENERIC SAFETY ISSUES o
EXTERNAL EVENTS o
INTEGRATED SAFETY ASSESSMENT PROGRAM (ISAP) o SEVERE ACCIDENT POLICY FOR FUTURE PLANTS o
SEVERE ACCIDENT CLOSURE /USE OF SAFETY G0AL 4
4 s
FIGURE 1 SEVERE ACCIDENT PROGRAM - SCHEMATIC m
IMPROVED PLANT OPERATIONS CONTINUING EVALUATIONS
- SALP
- MANAGEMENT REVIEWS
- DIAGNOSTIC INSPECTIONS 1 f
- .I I.:.:
IMPROVED ACCIDENT TECH SPECS MANAGEMENT L.:J[.
- .. Jp
////////
/////
l///////l
/
INDIV8 DUAL PLANT IDENTIFY PLANT
/k SEVERE ACCIDENT
//[
EXAMINATIONS
/
INTERNA VULNERABILITIES fi
-r CLOSURE j
7
/
HAZARDS f
f
/
/ / / /jg/ / / f
///
l///////
/
/
.v..-
OTHER POTENTIAL MARK I CONTAINMENT IMPROVEMENTS IMPROVEMENTS
- 5
-:i:j(-:-
3 SEVERE ACCIDENT U
~'
RESEARCH CONTINUING SEVERE ACCIDENT RESEARCH I:li
SUMMARY
o 10 CFR 50,54(F) LETTER REQUESTING IPEs o
BASIS:
COMMISSION SEVERE ACCIDENT POLICY ISSUED ON AUGUST 8, 1985 (50 FR 32138)
PLANT-SPECIFIC PRAs EXPOSED RELATIVELY UNIQUE VULNERABILITIES TO SEVERE ACCIDENTS UNDESIRABLE RISK CAN BE REDUCED BY LOW-COST CHANGES VIA PROCEDURES OR MINOR DESIGN MODIFICATION ANALYSIS WILL BE MADE OF PLANTS THAT HAVE NOT UNDERGONE AN APPROPRIATE EXAMINATION o
STAFF HAS INTERACTED EXTENSIVELY WITH INDUSTRY AND DEVELOPED APPROPRIATE DOCUMENTATION FOR THE IPEs o
PURPOSE OF IPE IS FOR THE UTILITIES T0:
IDENTIFY / UNDERSTAND THE MOST LIKELY SEVERE ACCIDENT SEQUENCES THAT COULD OCCUR AT THEIR PLANTS EVALUATE / IMPLEMENT MEANS FOR IMPROVEMENTS DEVELOP AN AWARENESS FOR SEVERE ACCIDENT BEHAVIOR 6
i IPE EXAMINATION PROCESS 0
LICENSEE'S STAFF SHOULD PARTICIPATE IN ALL ASPECTS OF THE IPE S0 THAT KNOWLEDGE GAINED BECOMES AN INTEGRAL PART OF OPERATING, TRAINING AND PROCEDURE PROGRAM e
o LICENSEES SHOULD CONDUCT SYSTEMATIC _ EXAMINATION OF PLANT DESIGN, OPERATION, MAINTENANCE AND $MERGENCY OPERATION T0:
IDENTIFY PLANT-SPECIFIC VULNERABILITIES (DESIGN AND PROCEDURAL) TO SEVERE ACCIDENTS (FOR BOTH CORE DAMAGE AND CONTAINMENT PERFORMANCE)
QUANTIFY RESULTS OF EXAMINATION FOR THE SEQUENCES THAT CONTRIBUTE THE MOST TO THE TOTAL CORE DAMAGE OR LARGE RELEASE FREQUENCY UNDERSTAND WHAT COULD PROBABLY G0 WRONG IN A PLANT IDENTIFY AND EVALUATE MEANS FOR IMPROVING PLANT / CONTAINMENT PERFORMANCE DECIDE WHICH IMPROVEMENTS WILL BE IMPLEMENTED AND SCHEDULE FOR IMPLEMENTATION 7
CONTAINMENT PERFORMANCE IMPROVEMENTS o
SOME CONTAINMENTS POTENTIALLY VULNERABLE TO EARLY FAILURE DURING SEVERE ACCIDENT (DRAFT NUREG-1150) o EVALUATING GENERIC CHALLENGES, FAILURE MODES 8 POTENTIAL IMPROVEMENTS o
STATUS FOR MARK Is:
APPROACH BEING PURSUED INVOLVES BOTH ACCIDENT PREVENTION AND MITIGATION ADDITIONAL SOURCES OF WATER BEING EXPLORED FOR CORE COOLING, CONTAINMENT AND DEBRIS COOLING, AND FISSION PRODUCT SCRUBBING ADS RELIABILITY ENHANCEMENT VENTING UTILIZING SUPPRESSION POOL FOR SCRUBBING USEFUL, BUT DOWNSIDES SHOULD~BE MINIMIZED REGULATORY ANALYSES OF AB0VE BEING PERFORMED
~
o MARK I INTERIM AND FINAL RECOMMENDATIONS DUE TO COMMISSION BY JULY AND FALL 0F '88, RESPECTIVELY o
RECOMMENDATIONS FOR OTHER CONTAINMENT TYPES DUE TO COMMISSION BY FALL '89 8
I
IMPROVED PLANT OPERATIONS o
MOST PRAs HAVE SHOWN SENSITIVITY OF RISK TO HUMAN ERRORS o
STAFF ANALYSES OF OPERATING EXPERIENCE CONFIRMS THE IMPORTANCE OF REDUCING MAINTENANCE, SURVEILLANCE, TESTING
& CONTROL ROOM OPERATOR ERRORS o
THEREFORE, STAFF'S PROGRAM TO IMPROVE PLANT OPERATIONS CONSIDERS THE FOLLOWING EFFORTS:
CONTINUED IMPROVEMENT OF THE SYSTEMATIC ASSESSMENT OF LICENSEE PERFORMANCE (SALP) PROCESS REGULAR REVIEWS BY SENIOR NRC MANAGERS OF PROBLEM PLANTS TEAM INSPECTIONS TO PROBE FURTHER THE PERFORMANCE OF THOSE PLANTS IDENTIFIED IN ITEM 2 REGULATORY ACTIONS TO IMPROVE OPERATIONAL PERFORMANCE WHERE IT HAS FALLEN BELOW EXPECTED STANDARDS IMPROVED TECHNICAL SPECIFICATIONS CONTINUED IMPROVEMENT OF OPERATING PROCEDURES EXPANDING E0Ps TO INCLUDE GUIDANCE ON SEVERE ACCIDENT MANAGEMENT STRATEGIES RESEARCH TO ESTABLISH THE SENSITIVITY OF RISK TO HUMAN ERRORS 9
SEVERE ACCIDENT RESEARCH BEGINNING IN 1980, AFTER THE TMI-2 EVENT, RESEARCH HAS PROVIDED A DATA BASE AND MODELS FOR:
o FISSION PRODUCT RELEASE, TRANSPORT, DEPOSITION, a REVAPORIZATION o
CONTAINMENT LOADING BY HIGH PRESSURE MELT EJECTION (HPE) o HYDROGEN DETONA. ION AND BURNING o
CORE / CONCRETE INTERACTIONS (CCI) o CONTAINMENT PERFORMANCE TESTING o
EFFECTS OF NATURAL CIRCULATION ON THE PRIMARY SYSTEM o
CORE MELT PREGRESSION (EARLY STAGES)
FUTURE RESEARCH EFFORTS WILL FOCUS ON SPECIFIC ISSUES SUCH AS:
o CONTAINMENT FAILURE PROBABILITY BY DIRECT CONTAINMENT HEATING (DCH) INCLUDING EFFECT OF NATURAL CIRCULATION o
MELT SPREADING AND POTENTIAL CONTAINMENT SHELL FAILURE IN MARK Is o
RESEARCH DATA AND MODELS TO ASSESS ACCIDENT MANAGEMENT STRATEGIES o
LONGER TERM CONFIRMATORY RESEARCH ON:
DCH CONSEQUENCES REFINEMENT OF HYROGEN BEHAVIOR MODELS CORE MELT PROGRESSION (LATE STAGES)
CORE / CONCRETE INTERACTIONS FURTHER MODEL ASSESSMENT AND REFINEMENTS 10
=
AN EXAMPLE OF AN ISSUE AND ITS ASSOCIATED NEAR AND LONG-TERM RESEARCH CONTAINMENT TYPE LARGE DRY PWR ASSOCIATED ISSUES o
POTENTIAL CONTAINMENT FAILURE MODES DIRECT CONTAINMENT HEATING (DCH)
HYDR 0 GEN BURN / DETONATIONS LATE FAILURE BY CCI LOADS (0VER T8P) o CONTAINMENT PERFORMANCE' o
ACCIDENT MANAGEMENT STRATEGIES DEPRESSURIZATION OF PRIMARY SYSTEM RESEARCH TO ADDRESS ISSUE o
DCH PROBABILITY OF HIGH PRESSURE MELT EJECTION (NATURAL CIRCULATION)
CUT 0FF PRESSURE FOR HPE MANAGEMENT THROUGH DEPRESSURIZATION CONSEQUENCES ANALYSES OF PERFORMANCE TESTS ON CONCRETE CONTAINMENTS (1/6 SCALE) 11 i
ACCIDENT MANAGEMENT o
ACCIDENT MANAGEMENT INCLUDES THE MEASURES TAKEN BY THE PLANT OPERATING AND TECHNICAL STAFF T0 (1) PREVENT CORE DAMAGE, (2) TERMINATE CORE DAMAGE IF IT OCCURS AND RETAIN I
THE CORE WITHIN THE REACTOR VESSEL, (3) FAILING THAT, MAINTAIN CONTAINMENT INTEGRITY AS LONG AS POSSIBLE, AND FINALLY (4) TO MINIMIZE THE CONSEQUENCES OF 0FFSITE RELEASES o
ACCIDENT MANAGEMENT ENCOMPASSES HARDWARE, HUMAN, AND ORGANIZATION FACTORS l
o IT PROVIDES DECISION MAKERS AT THE PLANT A STRUCTURED j
PROGRAM FOR MANAGING A SEVERE ACCIDENT o
PROPOSED IPE GENERIC LETTER ADDRESSES ACCIDENT MANAGEMENT AS FOLLOWS:
UTILITIES ARE EXPECTED TO DEVELOP AN ACCIDENT MANAGEMENT PROGRAM FOR PREVENTION OR MITIGATION OF RISK IMPORTANT SEVERE ACCIDENTS IDENTIFY MEASURES THAT PLANT PERSONNEL CAN AND SHOULD TAKE IN CASE OF SEVERE ACCIDENT.
ASSESS AGAINST THE CRITERIA 0F 10 CFR 50.59 AND, IF APPROPRIATE, SUBMIT FOR NRC REVIEW IN ACCORDANCE WITH 10 CFR 50,90 12
BOLE OF NUREG-1150 OBJECTIVE:
PROVIDES A SNAPSHOT OF THE STATE-0F-THE-ART PRA TECHNOLOGY, INCORPORATING IMPROVEMENTS IN METHODS AND DATA ACCUMULATED SINCE WASH-1400; INCLUDES EXAMINATION OF SEVERE ACCIDENT FREQUENCIES AND RISKS AND THEIR ASSOCIATED UNCERTAINTIES FOR FIVE PLANTS.
ROLES IN REGULATORY PROCESS:
INDEPENDENT STAFF ASSESSMENT OF R 'XS TECHNICAL DATA BASE AS INPUT T0:
IPE ACCIDENT MANAGEMENT CONTAINMENT PERFORMANCE INITIATIVES SAFETY G0AL IMPLEMENTATION GENERIC ISSUE RESOLUTION PRIORITIZATION/ FOCUS OF RESEARCH 13
SEVERE ACCIDENT CLOSURE o
DEFINES FOR INDUSTRY:
THOSE PROGRAMS WHICH ARE CRITICAL TO RESOLVING SEVERE ACCIDENT ISSUES FOR THEIR PLANTS SPECIFIC STEPS THAT MUST BE TAKEN TO ACHIEVE RESOLUTION o
ACTIONS MUST BE TAKEN FOR GENERIC ISSUES 8 PLANT-SPECIFIC ISSUES o
CLOSURE FOR GENERIC ISSUES RESULTS WHEN THE COMMISSION EITHER TAKES ACTION IN THE FORM 0F RULEMAKINGS, OR EXPLICITLY STATES WHATEVER ITS REQUIRED APPROACH IS; AND l
0 CLOSURE FOR PLANT-SPECIFIC ISSUES RESULTS WHEN EACH UTILITY HAS COMPLETED CERTAIN EVALUATIONS 8 IMPLEMENTED CERTAIN PROGRAMS SUCH THAT EVENTS WHICH COMPRISE DOMINANT CONTRIBUTIONS TO RISK ARE IDENTIFIED AND PRACTICAL IMPROVEMENTS (DESIGN, PROCEDURES, OPERATION) ARE MADE TO REDUCE PROBABILITY OF THESE CONTRIBUTORS OR THEIR CONSEQUENCES TO ACCEPTABLY LOW VALUES 14
USE OF SAFETY G0AL IN CLOSURE PROCESS O
SAFETY G0ALS AND OBJECTIVES WILL BE USED ONLY FOR RESOLUTION OF GENERIC ISSUES: RESOLUTION OF l
PLANT-SPECIFIC ISSUES WILL BE ACCOMPLISHED THROUGH IPEs AND PLANT-SPECIFIC BACKFIT CRITERIA o
SAFETY G0AL POLICY IMPLEMENTATION PLAN WILL BE PUBLISHED IN AUGUST 1988 AND WILL ADDRESS COMMISSION CONCERNS AND ACRS RECOMMENDATIONS o
ALL PRA INFORMATION WILL BE USED TO MAKE COMPARISONS WITH APPLICABLE SAFETY G0AL OBJECTIVES o
STAFF WILL DETERMINE WHY CERTAIN CLASSES OF PLANTS DON'T MEET S.G. OBJECTIVES AND ASSESS REASONS RELATIVE TO CURRENT REGULATORY REQUIREMENTS o
SUCH ASSESSMENT WILL TEST EFFECTIVENESS OF PRESENT REQUIREMENTS AND MAY RESULT IN CHANGES TO REGULATIONS AND SAFETY ENHANCEMENTS FOR SOME PLANTS o
SAFETY ENHANCEMENTS WILL BE SUBJECTED TO REGULATORY ANALYSIS PER COMMISSION'S BACKFIT RULE (10 CFR 50,109) AND PROPOSED TO COMMISSION FOR BACKIT IN THE FORM OF RULEMAKING o
FIRST APPLICATION WILL BE REFLECTED IN STAFF RECOMMENDATIONS TO COMMISSION ON BWR MARK I CONTAINMENT PERFORMANCE IMPROVEMENTS IN THE FALL OF 1988 o
IF APPROPRIATE ANY PROPOSED PLANT AND OPERATIONAL IMPROVEMENTS WHICH CAN NOT BE JUSTIFIED BY THE BACKFIT RULE WILL BE PROVIDED TO THE COMMISSION WITH THE STAFF'S RECOMMENDED ACTION OF A CASE-BY-CASE BASIS 15
RESOLUTION OF PLANT UNIQUE ISSUES o
IN PERFORMING IPEs, UTILITIES MAY FIND, AND IT IS EXPECTED THAT THEY WILL VOLUNTARILY REMEDY-UNC0VERED OUTL.IERS, AND MAKE ANY IMPROVEMENTS THEY DEEM APPROPRIATE, CONFORMING, HOWEVER, TO 10 CFR 50.59 0
HOWEVER, THROUGH THE REVIEW 0F IPE SUBMITTALS, THE STAFF MAY FIND IT NECESSARY TO EMPLOY PLANT-SPECIFIC BACKFIT POLICY TO ASSURE THAT JUSTIFIABLE PLANT-SPECIFIC IMPROVEMENTS ARE MADE 4
16
CLOSURE PROCESS o
STEPS WHICH EACH UTILITY IS EXPECTED TO TAKE TO ACHIEVE CLOSURE OF SEVERE ACCIDENT ISSUES FOR ITS PLANTS ARE:
COMPLETE THE IPEs, AND IDENTIFY POTENTIAL IMPROVEMENTS, EVALUATE AND FIX AS APPROPRIATE I
DEVELOP AND IMPLEMENT A FRAMEWORK FOR AN ACCIDENT MANAGEMENT PROGRAM THAT CAN ACCOMMODATE NEW INFORMATION AS IT DEVELOPS IMPLEMENT GENERIC REQUIREMENTS RESULTING FROM CONTAINMENT PERFORMANCE IMPROVEMENTS PROGRAM o
SEVERE ACCIDENT RESEARCH WILL CONTINUE TO CONFIRM JUDGMENTS: NEW ISSUES WILL BE HANDLED ON A CASE-BY-CASE BASIS 17 I
A i
TABLE 1 i
Schedule and Expected Commission Actions for Severe Accident Issues Item Schedule Expected Commission Action 1
1.
Individual Plant Commission Paper Commission will be requested Examinat. ions due July, 1988 to approve issuance of generic letter initiating IPEs 2.
Containment Performance a
Improvements a) BWR MARK Is Interim recommendations Approve staff recommendations due June, 1988 and Commission Paper with final recommendations due Fall, 1988 b) Other Containment Commission Paper Approve staff recommendations Types due August, 1989 3.
Improved Plant Continuous None at this time Operations 4.
Severe Accident Continuous None at this time Research Program 5.
External Events Commission Paper Approve st'aff recommendations due end of FY 89 for treatment of external events in severe accident policy implementation 6.
Accident Management Commission Paper None--Paper for information Program due Fall, 1988 only 7.
NUREG-1150 Commission Paper None--Paper for infermation scheduled for only Janua ry, 1989 8.
Generic Safety Issues Continuous None at this time 9.
Integrated Safety Commission Paper No action anticipated Assessment Program due June, 1988 at this time 10.
Advanced Reactors a) LWRs Commission Paper Approve staff recommendations due July, 1988 b) Non-LWRs Commission Paper Approve staff recommendations due June, 1988 11.
Safety Goal Policy Commission Paper Approve staff recommendations Implementation due August, 1988 l
18
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