ML20235S757
| ML20235S757 | |
| Person / Time | |
|---|---|
| Issue date: | 07/15/1987 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 8707210768 | |
| Download: ML20235S757 (80) | |
Text
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i UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
Title:
Briefing on Mark I containments status Location:
Washington, D. C.
Date:
Wednesday, July 15, 1987 Pages:
1 - 62 l
Ann Riley & Associates Court Reporters 1625 l Street, N.W., Suite 921 Washington, D.C. 20006 (202) 293-3950 8707210768 870715 1 OUR PDR
,q t
4 em I-1' 1
D I SC LAl MER 1
l 3
4 l
5-6 This is an unofficial transcript of.a meeting of'the 7
United States Nuclear Regulatory Commission held.on 7/15/87 S
c.
In the Commission's office at 1717 H Street, 9
N. W.., Washington, D.C.
The meeting was open to public 10 attendance and observation.
This transcript has not been 11-reviewed, corrected, or edited, and it may contain
[
12 inaccuracies.
13 The transcript is intended' solely for general 14 informational purposes.
As provided by 10 CFR 9.103, it is 15 not part of the formal or informal record of decision of the 16 matters discussed.
Expressions of cpinion in this transcript 17 do not necessarily reflect final determination or beliefs.
No 18 pleading or other paper may be filed with the Commission in 19 any proceeding as the result of or addressed to any statement 20 or argument contained herein, except as the Commission may i
21 authori=e.
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22 23 24 J
25
_ _ _ _ _ = _ _ _ - - -
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UNITED STATES OF AMERICA
)
4 2-NUCLEAR REGULATORY COMMISSION 3
4 BRIEFING ON MARK I CONTAINMENTS STATUS-5
~
6 PUBLIC MEETING 7
8
' Nuclear Regulatory Commission 9
Room 1130 10-1717 H Street, Northwest l
11 Washington, D.C..
I 12 13 Wednesday, July 15, 1987 14 15 The Commission met'in open session, pursuant to 16 notice, at 10:00 o' clock, a.m., the Honorable LANDO W.
- ZECH, 17 Chairman of the Commission, presiding.
18 COMMISSIONERS PRESENT:
I 19 LANDO W.
- ZECH, Chairman of the Commission 20 THOMAS M. ROBERTS, Member of the Commission 21 FREDERICK M.
BERNTHAL, Member of the Commission i
.22 23 k
24 25 i
a
2 1
STAFF AND PRESENTERS SEATED AT THE COMMISSION TABLE:
l, 2
j 3
S.
CHILK l
4 W. PARLER 5
E. BECKJORD
,6 T. MURLEY 7
T. SPEIS-8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
0 : c. --
3c
.1 P R' O C E' E; D I N G S 2'
- CHAIRMAN ZECH:. Good ~ morning, ladies and gentlemen.
3' CommissionerLCarr Will not be with us today.
TL's morning, the. commission will'be briefed byfthe i
'4 5-l Staff onLthe status of the proposed regulatory initiatives to 6
enhance'thefsafety of boiling water reactors in MARK-I
.f 7
containment. designs.
.These proposed regulatoryf nitiatives are.
i
'8-in response to concerns'about.the performance of.these
'9 containments during1a severe core melt accident and are tied to 10 the Commission's defense-in-depth philosophy.
11 This meeting is.a follow-on to the November 1986-12 meeting.on thelsame subject. 'It is my understanding that the
.13' Staffris' developing a comprehensive plan to address this-issue, 14 and we.will hear about that:this morning.
15 This is an information briefing, and no vote is
~
16 anticipated today.
.17 Are there any opening remarks by my fellow
(
18 Commissioners?
19'
[No response.]
20 CHAIRMAN ZECH:
If not, Dr. Murley, will you proceed.-
21 MR. MURLEY:
Thank you, Mr. Chairman.
22 Mr. Stello is off today, and as you probably know, 23 due to the alert at the North Anna plant, the agency is in l
24 stand-by, so Jim Taylor is at the response center.
So I will 25 stand in for Vic Stello and talk about the approach.
I've had j
3
.____-_-____ __ __ __ _-______ - - _ A
i 4
1 many discussions with him on this subject.
2
[ Slide.]
3 He asked me back in April if I would look into the 4
subject of MARK-I containments and make some recommendations to 5
him, so we will do that today, and we will broaden it somewhat 6
to have, as you indicated, a more comprehensive approach to the 7
issue, and we will include plant operations and individual 8
plant examinations as well as containment research.
9 I should lead off by saying that we believe that what 10 we're saying today is absolutely consistent with the severe 11 accident policy that we mentioned back in August of 1985, where 12 the Commission stated then that the existing plants pose no 13 undue risk to public health and safety.
There was no basis at 14 that time for immediate action on generic rulemaking, but that 15 nonetheless we should continue to look at severe accidents.
We 16 believe that that is still the case today, and that's where 17 we're starting from.
18 As I began to look into these issues, it was my own 19 personal reentry into some policy issues from several years in 20 the Region, and I began looking at the Severe Accident Policy 21 Statement, the MARK-I initiatives, the safety goals, the severe 22 accident research program, the source term reevaluation, and 23 quite frankly I didn't see how it was all tied together.
So 24 that's what caused me to think that perhaps we needed to take a 25 broader look at some of these issues.
And particularly, I
o.
5 1
didn't see how it would lead -- how these policies were leading 2
to closure of the severe accident issue.
3 And by " closure," I don't mean a defined set of tasks
{
I 4
that you can check off, and when they're done, you can say, I
5 yes, we've actually closed the issue for all time.
It's more 6
of an intellectual concept, that all the ingredients are in 7
this plan, and that if you work on these ingredients and S
complete them, then, yes, you can see your way through to 9
closing the severe accident issue.
And, of course, that's 10 really the main issue that we have in front of us in terms of l
l 11 safety today, is the severe accident issue.
So once you've 12 laid out a plan to at least intellectually lead to closure of 13 that issue, you've, it seems to me, basically dealt with the 24 major safety issues facing us.
15
[ Slide.]
16 There was a gap that I saw in a number of these 17 policies and initiatives, and that gap was how improved 18 operations fit into the whole thing.
And coming from Region I, 19 of course, that was virtually ny -- well, what we spent our 20 whole time on in the Region, was improved operations.
21 So I think that was important to weave that in also 22 to the whole approach to dealing with MARK-I containments and 23 improved safety.
24 So if I could have the next slide, please?
25
[ Slide.]
6 1-Now let's move on to the next one.
2
[ Slide.]
3 This is a schematic approach or an outline, really, 4
of the elements that I think need to be in a comprehensive 5
severe accident program, and it starts at the top with improved 6
plant operations, which I think is something that the agency is 1
7 going to be always dealing with.
I think virtually all the 8
plants out there can stand to improve their operations.
We, in 9
the NRC, can continue our improvements of the SALP program, our 10 management reviews, looking for performance that might not meet 11 our standards, 12 In addition, we have specific products that are 13 destined to come out in the next few months and even a couple 14 years.
First, of course, is the improved tech specs.
That is 15 very important to us.
I think it's important to the industry 16 as well, that we get cleaned up and improved tech specs.
17 We would like to move into improving emergency 18 operating procedures, even to the point where we have 19 procedures for severe accidents themselves.
So we see that 20 we're moving into that area.
21 And as I said, we expect that the nature of improved 22 plant operations is such that NRC is going to continue to be in 23 this area for quite some time.
24 In addition, the Severe Accident Policy Statement 25 contemplated that we would be doing individual plant
7 1
examinations.
These would either be comprehensive probablistic 2
risk assessments or a surrogate' type of examination developed 3
by the industry with NRC approval.
We are now at the stage 4
where we.think.that we're ready to move ahead, and Dr. Speis on 5
my right will talk about that in just a few minutes.
6 Clearly, it has a central role to play in leading to 7
closure of severe accidents, because this is the effort where 8
each plant will look for vulnerabilities of its unique design 9
and where we feel that improvements are needed.
Then this will 10 be the basis for our requiring improvements to deal with severe 11:
accidents.
12 COMMISSIONER BERNTHAL:
Tom, this is all useful 13 background, but I'm trying to see what the message is that's 14 coming through and also is implicit in, I take it, in Mr.
15 Stallo's memorandum to the Commission of the 8th of July.
16 Are you suggesting that in this middle box here, 17
" Identify plant vulnerabilities," -- and in this case, we're 18 talking about potential vulnerability in a collection of plants 19
-- that the particular issue at hand and on the table here, 20 that's been on the table for about six months now, I guess --
1.
21 that in the larger scheme of things, it is the view of the 22 Staff that this is not a particularly more serious issue in i
23 vulnerability, if you will, than many others that you feel are 24 outstanding?
25 Is that what I'm supposed to read into this?
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1 MR. MURLEY:
It will be -- the MARK-I issue will be 2
dealt with, and it will be dealt with early.
Let me get on to 3
that in just a second, and then Themis will deal with the 4
details.
I 5
So let me then move on to containments.
And I need 6
to, I think, go into a little background on the containment 7
issue.
8 First, I think we all know that the containments were 9
not-originally designed to deal with core melt accidents; they 10 were designed to deal with large-break LOCAs.
I was up at MIT 11 yesterday, and I had a chance to talk with Professor Rasmussen 12 again, just to refresh my memory, and it was correct.
In WASH-13 1400, it was acknowledged, it was assumed at that time, that 14 containments would always fail in a core melt accident, 100 15 percent of the time.
And they would either fail through steam 16 explosions, through human error, inadvertent opening of the 17 containment, or if not that, then a hydrogen explosion or an 18 overpressure failure or ultimately meltthrough of the basemat.
19 So failure of containment was assumed in all the risk 20 studies that we've been dealing with since WASH-1400.
Now 21 we've sharpened our pencils since then, and, in fact, we know 22 that steam explosions are not as serious as we thought they 23 were thirteen or fourteen years ago, and that the containments 24 are more rugged than we thought then.
And nonetheless, even 25 with the assumed failures in that risk study, the containments
9 1
.are an important mitigating feature, because the fact that they-21 fail.is not so important as when they fail.
I 3
And so, as I said,.research has shown that 4
containments do provide a good deal'of mitigation.
And when I 5-say 100 percent of containments, I meant the large drys, as 6
well as MARK-Is and the rest.
7 COMMISSIONER BERNTHAL:
When you say that 8
containments have been demonstrated to be more robust than we 9
expected, I assume that you are also talking primarily about 10 the PWR containments, particularly the large drys.
11 MR. MURLEY:
Yes.
I guess I should have qualified 12 that, Commissioner, and said that the steam explosion 13 phenomenon'was not as severe a challenge to containment as we 14 thought.
15 COMMISSIONER BERNTHAL:
Right, right.
16 MR. MURLEY:
Yes.
There's two things.that have 17 happened.
Of course, last year in April of 1986, the Chernobyl 18 accident has highlighted the importance of containments and the 19 importance of particularly having containment there during the 20 early stages of the accident.
21 In addition, during the last summer, there were a 22 number of meetings among the NRC Staff, the industry, and the 23 experts.
Bob Bernero put forward a number of proposals to 24 improve the MARK-I containments, and they were discussed among 25 the experts with the industry.
And as I read what emerged from
e 10 1
those discussions, there was, in fact, no consensus developed 2
on what is needed to improve the containment, how effective the 3
proposed modifications would be, and even such things as how 4
much the modifications might cost.
5 So what we are proposing is that we deal with the 6
MARK-I containment issue in the context of a broader look at 7
severe accidents, that we deal with it early, and that we try 8
in the next few months to develop a consensus where we can.
9 So that's the overall message today, and Themis Speis 10 is going to talk about the details, if you'd like to move on.
11 I should say that continuing containment research is 12 going to be important because I think we have got a mortgage 13 that we have to pay off, if we assume we will reach closure on 14 severe accident, at least conceptually, sometime down the road.
15 There is still going to be the need for, I think, continuing 16 containment research, as far as we can see.
That's because we 17 won't have looked under all the rocks and some will continue to 18 pop up.
19 I think we and NRR will be working with Eric in 20 research in helping to plan that program over the next few 21 years.
22 With that introduction, Themis Speis will talk about 23 where we are going in detail.
24 CHAIRMAN ZECH:
Fine.
You may proceed.
25 MR. SPEIS:
Thank you, Mr. Chairman.
4..
11 1
'[ Slide.]
2
'MR. SPEIS:
I want to be as crisp as,I can about 3
where we stand on'the Mark-I containments.
As you, Mr.
4 Chairman, indicated in your opening. remarks, I might have to 5
repeat a few things that Tom said in the last two' minutes or 6
so.
7 During the past year, as all of us know, the staff developed a proposal for enhancing the performance of Mark-I 8
9 containments given a severe core melt accident.
10
-[ Slide.]
11 MR. SPEIS:
This viewgraph shows the five items that 12 were part of the proposal.
As Tom already said, we discussed 13 this with industry representatives.
For example, with NUMARC, 14 with the.BWR owner groups, with the individual utilities.
We
'15 also briefed the Commission on November 3, 1986.
We briefed 16 the ACRS on Lecember 9th and also we briefed the CRGR.
17 Initially, we thought that possibly this improvement 18 should be implemented via a genetic letter to the industry.
If 19 you recall, Mr. Chairman, the Commission in an SRM requested 20 that we evaluate the number of options related to the 21 resolution of the Mark-I issue.
22 For example, whether it was prudent to proceed via a 23 genetic letter as against proposed rulemaking or even whether 24 we should be folding the issue of Mark-I improvements as part 25 of the implementation of the severe accident policy statement.
I s
12 1
Also, the ACRS and the CRGR raised a number of 2
questions about the technical justifications of some of the 3
items that are listed in the proposal.
4 For example, the ACRS in its letter said that the 5
proposal lacked detailed technical justification.
This brings 6
me to the last point Mr. Murley made, on February 3, Mr. Denton 7
and Mr. Bernero put together in one room all the key scientists
]
8 from the laboratories and the universities that have been j
9 working with us in this area, to discuss the efficacy of these 10 proposed improvements.
11 As Tom said, the views expressed at these meetings 12 were very wide.
They were all over the place.
The conclusion 13 that seemed to emerge from that meeting was at least for now, 14 then when the meeting took place, there was no clear consensus 15 as to whether the improvements were needed or whether the cost 16 estimates were realistic or whether this was the right mix of 17 proposals that should be pursued in improving.the containment 18 performance, the Mark-I containment.
19 After reviewing these matters very carefully, we have 20 conc]uded that additional assessments are needed to arrive at a 21 ber.ter understanding of the challenges and failure modes which 22 could then be used to support recommendations.
23 It's very important that one understand as precise, 24 and I shouldn't use that word in this range of severe 25 accidents, as good as possible, the failure modes themselves.
13 1
Only then can one propose mitigating fixes.
If you don't know 2
where it fails, at what location, at what time it fails, then s
3 you might be proposing something that is not going to be very 4
effective in doing what you thought you were after.
5 Mr. Denton then took the package and when the 6
reorganization took place, he recommended that the allocation 7
of the necessary resources to evaluate the efficacy of this 8
containment improvement be pursued.
9 Later on in the presentation, I will discuss the 10 resources program to pursue in more detail work and resources 11 relating to containment performance improvements not only for 12 Mark-I but for all containments.
13 As Tom said, this issue is only a part of the total 14 issue of coming to grips with the issue of severe accidents.
15 In fact, this is really a subset of the larger effort which we 16 are pursuing with the nuclear industry in the implementation of 17 the Commission's policy statement.
18 The key part of that and a big ingredient of that is 19 the individual plant examinations Tom alluded to.
20
[ Slide.)
21 MR. SPEIS:
Let me say a few things about this 22 effort.
We will be briefing you in more detail in the next few 23 months when we are ready to send the generic letter to the 24 industry.
25 If you recall, in the Commission's severe accident
4 141 1-policy statement, there were three actions dealing with new-L2 applications,.with existing' plants;and with changes.in rules 3
and regulatory practices'as needed.
I will focus on the second-4 one, for existing plants.
Tom already said in his opening 5
remarks that the Commission atLthat time decided-or reached the 6
conclusion that there was no need to pursue any hasty. rules or
~7 improvements because the Commission reached the conclusion'at that time that the plants were safe.
8 9
Because previous studies, among'them, PRA's and 10 LER's, have' indicated that every plant-has some unique problems 11 that could be really plant specific, then the prudent thing was
~ 12 to develop a methodology in conjunction with the nuclear i
13 industry to look at every plant specifically.
Based on what 14 was found, then put those findings on the table and of course, 15 the program itself addresses not only containment performance-16 but addresses the challenges to the core itself, what are the I
1 17 things that'would lead to a severe core damage accident.
18 Once we have the things that could be further l
1 19 improved, whether they deal with prevention or mitigation, then f
I 20 one can make a more balanced or reach a more balanced decision
{
l 21 on where should one put his money, as they say.
l i
J 22 COMMISSIONER BERNTHAL:
I'm not sure I understand
)
23 what we are saying here.
Again, back to the question, is the 24 suggestion that this particular class of reactor and 25 containment in particular, that staff has evaluated the l
1 l
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_____________________________-__-_____-_____a
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technical elements of this class of containment, that we have 2
reached a preliminary judgment based on the PRA's or whatever 3
other factors the staff should be considering, that they do~not 4-merit special attention outside the normal confines of the 5
severe accident program?
Is that what we are saying here?
6
-Is that what we have learned in the last eight months 7
we have been considering this?
8 MR. SPEIS:
We are saying that to some extent, we are 9
not being very absolute about it.
In parallel, the IPE will be 10 looking in more detail at containment performance improvements.
11 As I said, Commissioner Bernthal, it is very important that we
^ 12 really_ understand what are the failure modes and when they fail 13 and how they fail before one can put together the proper mix of l
l 14 proposals or enhancements that will further reduce the risks.
15 To be more blunt, if you look at NUREG-1150, it 16 doesn't say that Mark-I is an outlier, for example.
17 COMMISSIONER BERNTHAL:
In terms of risk, I agree.
18 In terms of containment performance, it is.
19 MR. SPEIS:
In terms of containment performance, yes.
20 It is not as good as some of the other containments.
21 As I say, at the end of the presentation, I have a 22 schedule, where we are going to pursue aggressively in parallel 23 with the IPE.
We hope that the IPE process itself, which will 24 be looking not only at the front end but the back end, 25 prevention, mitigation, will take some of those things.
_-------_-------__-_------_J
y_
to 16-1
'There are'some things that are indeed very generic.,
2 Those things we will be pursuing in. parallel.
We<are not 3
slacking.off.
4 COMMISSIONER BERNTHAL:
Have we'also made the 5-
' decision:to proceed with the generic letter?
6 MR. SPEIS:
Yes.
7-COMMISSIONER BERNTHAL:
That was the. recommendation
.i 8
'of the ACRS?
9 MR. SPEIS:
Yes.
I will discuss that.
10 COMMISSIONER BERNTHAL:
The ACRS was not in fact at 11 that time, being December, I guess, even willing.to say that we 12 should not proceed with individual plant. evaluations?
Have we 13 rea'ched'a decision on that, not to proceed with individual 14 plant evaluations?
15 MR. SPEIS.:
At least at my level, I would be 16 recommending to my boss that we should proceed with individual 17 plant examinations.
I guess my reading of the ACRS letter is a 18 little bit different than yours.
19 The ACRS letter said that in general, they agree with 20 the approach, with our review of the IDCOR methodology, but 21 they raised three specific questions.
They want us to be more 22 definitive in focusing on containment improvements.
They
{
23 wanted us to clarify further the criteria that one uses for 24 assessing or pursuing vulnerabilities.
They wanted us to think 25 carefully about picking up a number of trial plants.
We will e
4
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4 17 1
take care of those things very carefully and consider those
.2 things, but we will be taking into account the ACRS I
3 recommendations.
1 4
COMMISSIONER BERNTHAL:
You are quite right.
They 5
did consider that we needed more information and more study on-6 the technical issues.
To make the record very clear, they said 7
as follows "Until sufficient information has been developed on 8
these matters..." the three issues you referred to,
...we are 9
unwilling to agree with the proposed position in the draft 10 generic letter," "...given the implementation of.the generic 11 requirements of Mark-I containments, there is no need for an 12 individual plant evaluation for containment performance."
13 They were not willing at that time to suggest that wo 14 should not go ahead with individual plant evaluations.
Then 15 they said, nevertheless, the staff should' issue the proposed 16 generic letter for public comment.
17 MR. SPEIS:
I think for the last few minutes, you are 18 going this way and I have been going this way.
You are talking 19 about the generic letter on the Mark-I improvements.
I was 20 referring to the generic letter on the individual plant 21 examinations.
I am sorry.
22 COMMISSIONER BERNTHAL:
They did recommend we proceed 23 with the generic letter on the Mark-I containment improvements.
24 You are telling me the staff has reached a decision we should 25 not do that.
y 18 4
1-MR. SPEIS:
Not at this time.
Not immediately.
2 Depending on how the IPE process proceeds and how the parallel 3
effort on containment improvements, if we indeed reach a 4
conclusion that we understand the proper failure modes, the 5
right failure modes, and we have some generic concerns, we will 6
come to you and say maybe the best way would be to proceed with I
7 rulemaking.
In fact, that was the Commission's policy 8
statement of a few years ago.
9 Plant specific fixes, use the backfit tool, but if 10 things have to be done on a more generic basis, proceed by 11 rulemaking.
12 We haven't reached that conclusion.
That is what our 13 thinking is.
14 COMMISSIONER BERNTHAL:
We have also reached a 15 decision or the staff is recommending not to follow the 16 procedure that as I recall, Commissioner Roberts indicated 17 eight months ago he preferred or six months ago, i.e.,
to 18 follow a rulemaking procedure.
I take it we are not going to 19 do that.
20 MR. MURLEY:
Not at this stage.
I don't know where 21 it might lead.
22 MR. SPEIS:
I think it will be more clear if I go 23 through the presentation and talk about the idea and what we 24 think might come out of it and the last viewgraph, when I talk 25 about the parallel effort dealing with containment issues and
j J
-.o-19 1
then when I talk about the schedule.
2 CHAIRMAN ZECH:
Isn't it true you have not come to 3
that conclusion yet?
4 MR. MURLEY:
That's right; we have not.
5 CHAIRMAN ZECH:
You could?
6 MR. MURLEY:
The conclusion that we have come to is 7
that Ue need to take a broader look at this issue, that Mark-I 8
containments and any improvements need to be an early part of 9
that look, and we need to proceed with the individual plant 10 exams as contemplated, but short of that, we haven't come to 11 any firmer conclusions.
12 COMMISSIONER BERNTHAL:
I don't necessarily take 13 issue with the procedure that you have outlined and obviously 14 not with the need to put this at the front end of our broad 15 cons'ideration of severe accidents.
16 I am also very interested in hearing what we have 17 learned in a technical way in the last six months and also 18 about the cost estimates that staff night or might not have 19 been able to develop in the last six months.
20 MR. SPEIS:
Let me proceed with the individual plant 21 examinations.
This was in the Commission's policy statement as 22 said already.
The Commission told us to go ahead and develop a 23 systematic approach for the examination of individual plants.
24 We have worked with industry and methodology has been 25 developed.
We have discussed this with the ACRS.
s
j l
20 1
I might want to say at this point in time, the staff 2
will recommend also some other methodologies like a modern PRA 3
could be the proper vehicle, not necessarily the method IDCOR 4
has developed.
5 Basically, the objective of the IPE is to perform a 6
systematic examination of plant design, operation, maintenance, 7
emergency operations, and as I said already, to be performed 8
using the IPE, IDCOR's IPE methodology of a more modern PRA.
9 The key part is to identify plant specific 10 vulnerabilities.
There could be either design or procedural to 11 severe accidents.
I want to stress again a key part which 12 covers both core damage and containment performance, preventing I
13 accidents as well as mitigating them.
I 14 MR. MURLEY:
In that sense, excuse me, Themis, we do 15 agree with the ACRS in that sense, that we should include 16 containment performance in the individual plant examination.
l 17 We do agree with that.
l I
18 MR. SPEIS:
We do agree; yes.
Again, I was sorry.
I l
19 thought Commissioner, you were reading another ACRS letter.
20 The important thing is for the utilities to 21 understand what could possibly go wrong in a plant.
I think 22 one of the important things that hopefully will come out of the 23 IPE is a severe accident management program, as Mr. Murley said 24 earlier, following the identification and evaluation of the j
25 means for improving plants and containment performance, which
^^---
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21 1
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.could be'via: hardware additions, modifications, additions to l.
t:
2 procedures and; training, that thos* insights,-that' knowledge, 3
should be folded into a prcgram and hopefully be? expanded and-4 stay there.
As Tom said, it should be the vehicle for other.
L 5.
improvements from the operations' standpoint, Tech specs, and 6
other things that Tom said earlier.
~
l 7
I want to say a few things about how we plan to.
8 implement the1 individual plant examinations.
9'
[ Slide.)
1C MR. SPEIS:. We plan to do'it by generic letter.
The.
11 lawyers.are telling us that the' Commission's severe accident-
'12; policy statement.provides the basis.
13 MR. PARLER:
This is for what?
14' MR.'SPEIS:
The generic letter.
We will discuss 15 this.
We will send you the package with all-the legal 16 arguments about it.
You gentlemen will have a chance to 17 decide.
I am just telling you what the lawyers have told us so 18 far.
19 MR. PARLER:
I will, have to look through that.
20 That's why I interrupted you.
I'm not aware of any reason why 21 you need to put a generic letter out for something like this.
22 There shouldn't be any legal problem.
After all, the reason 23 for being here is to protect the public health and safety from l
24 the operation of nuclear plants and nuclear materials.
I 25 wouldn't necessarily view legal problems as cbstacles to what i
m____.__ _. _ _ _ _ _ _ _ - _ - - - - - - - - - - - - ' - -
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,3 3
22 l
.1J tyou-are trying to describe.
2
- IOR.. SPEIS
We are an. agency that has to pursue the.
3 safety.and technical matters butlwe have to do-it in'the. legal
'4 framework.
5 MR. PARLER:
No. question about that.
6 CHAIRMAN ZECH:
We all agree.
Let's proceed.
.7'
.MR. PARLER: ~All.I am.trying to tell you is a legal-8 obstacle will not stand.-in the way of;doing what'you want ton 9
'do.
10 COMMISSIONER'BERNTHAL:
You certainly can put out a 11
. policy statement without worrying about legal obstacles,fto the 12 best of my knowledge.
13 MR. SPEIS:
The first phase of the IPE will be to 14 identify significant' severe accident sequences, identify 15-potential areas for improvement and as.I said, establish an 16 accident management program.
17 The second phase will be to identify plant specific
'18 corrective actions, which of course includes a severe accident
'19 management program, i
20 The generic letter specifies three options'that could 21 be used to satisfy the examination requirements, the IDCOR 22 IPEM, some Level II or III PRA or some other systematic
,23 evaluation method that the staff might find acceptable.
24 (Slide.]
25 MR. SPEIS:
The next viewgraph discusses something --
x
~ * '
23
- 1 COMMISSIONER' ROBERTS:' Let me ask you a question, you; e
2 are:goingLto do this11n a generic way, don't.you suspect the 3
bulk of this information is out there.today for a' specific 4
_ plant?
S' MR. SPEIS: -This is to'do the examination.
The
!6 letter will.say,-here is an acceptable methodology or some-7:
other-methodology and this is the framework,.these areLthe.
8 types of things we are. talking about.< This is what.we would 9
'like to see, how the information should-be utilized, kind'of'a 10 general guidance.
11 MR. MURLEY:
I think perhaps, Commissioner, what you 12 might be getting at is-when we do -- we have done enough risk:
13 assessments now that some common things show up in all of them.
14 The importance of ATWS for boiling water reactors and that sort 15 of thing, a station black-out seems to show up.
'16 Yes.
There is a lot of information that a plant can 17 use, even if he hasn't done a PRA, to go'look at his own-plant
.18 '
for vulnerabilities.
Having said that, there is another side
.19 to the coin and that is every PRA that I know has been done 20 today has also found some plant unique weaknesses.
That's 21 important also to look for.
We don't know just how severe
~2 2 those weaknesses are.
We think we have found just about 23 everything now, but there is no doubt we will continue to find 24 things as we do these studies.
25 CHAIRMAN ZECH:
Could you go back to the generic
.1
',4 24 1-letter viewgraph for a-moment?
.2
' [ Slide. ).
3 CHAIRMAN ZECH:: In phase two, where you say identify
.4.
plant specific corrective actions, does that mean.the' staff's' 5
' proposed criteria are going to be specific enough to identify 6
where corrective actions should be taken? 'Is that what you:
7 intend by that?
8 MR. SPEIS:
To some extent.
I will discuss that in 9
the next viewgraph, Mr. Chairman.
I will address that.
- Yes, 10 to the extent possible.
I think we don't want to be as 11 specific.
We want to provide general guidelines.
There could 12
.be plant specific things, only some general framework can be 13 given to the plant and the plant itself will go look for plant 14
-specific --
15 CHAIRMAN ZECH:
You will review that?
16 MR. SPEIS:
We will review that.
17 CHAIRMAN ZECH:
And make a determination as to 18 whether specific action should or should not be required, I 19 presume.
20 MR. SPEIS:
Yes; that's right.
21 CHAIRMAN ZECH:
Thank you.
22 MR. SPEIS:
Again, this is a very brief summary.
It 23 is just the essence of the generic letter.
It is not the whole 24 thing.
25 CHAIRMAN ZECH:
I understand.
I iust want to know s
25 1
how specific you are going to get in that phase two.
2 MR. MURLEY:
There is a point that I would like to 3
emphasize.
I probably didn't emphasize it enough.
That is in 4
phase two, there is an item that says include severe accident 5
management planning.
One of the outputs that we would expect 6
to come out of this as well as the human factors program, 7
working jointly together, are some procedures for severe 8
accidents themselves.
9 That is once you are into core damage and maybe even 10 core melt, our procedures basically stop other than some 11 general guidelines.
We know that the French have developed 12 such procedures.
We think we can usefully move into that area 13 with at least general guidelines.
There will be no doubt plant 14 specific aspects to those guidelines, too.
That's one of the 15 things that will come out of phase two.
16 CHAIRMAN ZECH:
Thank you.
17 COMMISSIONER BERNTHAL:
I think we are all sort of 18 dancing around the same question here, which is still not 19 entirely clear to me.
20 We are going to, I gather, ask utilities to proceed 21 with an individual plant evaluation, examination, and try to' 22 determine plant specific vulnerabilities.
Is that assuming at 23 that point, the outcome of our PRA's and the staff's technical 24 evaluation perhaps even as of today, indicates there are 25 generic vulnerabilities?
e
.o l.,.
[11, 1
^-
'26 (1
'I'd like to hear a little bit about-what'we have 2
' concluded' generically about'the plant. vulnerabilities and what 3
'can'go' wrong in a plant.
I'll grant'you that eachT ndividual i
4L plant'unfortunately in ourfcountry has nuances and are a little 5
' bit different.
You would need then to look at eachLindividual 6
plant.'
7
'On.what basisswould we-proceed to'that point?-
'8 MR.' SPEIS:
.I will tell you what our perception is of 9
the contAinmentifailure' modes'for Mark-I,.for example, and 10 right now, we don'tLthink - ~the five-fixes might.be the right 11 ones,.for example.
I.will do that~when we get to.that part.
12 (Slide.)
13 ER. S PEIS ':
The next viewgraph tries to summarize 14 some of the things we have been talking about the last few 15 minutes.
In addition.to the generic letter, we will attach to 16 the generic letter a package for each. containment type.
This-17 package is~ called guidelines and criteria.
What we have done, 18 we'have gone through all the PRAs that both industry and we 19 have performed including the IDCOR analysis on four' reference 20 plants, including the NRC's analysis of the five reference 21.
plants, documented in NUREG-ll50, including'what the Europeans 22 have been doing, and we kind of put this knowledge and insights 23 together and sorted it out according to applicability, reactor 24 type, and assembled it into guidelines and criteria.
25 Really, it is the utilization of past experience and
27 1
insights, based on PRA insights as well as the analyses.
2-These guidelines identify as precisely as we can at i
3 this time plant features and operator actions which previously 4
have been found to be important risks.
The guidelines also 5
highlight potential areas of improvement in various areas of 6
plant design and operations, both to prevent and to mitigate 7
accidents.
8 The criteria are the appropriate standards for 9
assessing performance of specific plant features or operator 10 actions identified in the guidelines.
For example, the 11 criteria addresses such thing as equipment capabilities, 12 capacities, duration of operability, availability of support 13 systems and identification of the necessary components, and the 14 things listed there.
15 Also, for example, the guidelines include things that i
16 we have learned in the area of mitigating accidents and things 17 that some of the Europeans have decided to go ahead and 18 implement.
For example, for the Mark-I containment, the 19 guidelines and criteria acknowledge the importance of drywell 20 sprays and containment venting in reducing the probability of 21 containment failure.
22 This is kind of an ensemble of everything we have 23 learned from previous experience.
It is the accumulated 24 wisdom.
We are providing this as guidelines but not specified, 25 do thic or do that.
Every plant is somehow different, s
i h__-______
28 1
fortunately.or unfortunately.
We cannot.say do this because 2
this may not be the right thing for one plant and may be-the.
3 right thing for another plant.
4
~ The generic letter and the guidelines.
We hope this 5
systematic examination and.the guidelines'and' criteria provide 6
all the necessary guidance needed to conduct an IPE for severe 7
accident vulnerabilities.
8 (Slide.]
9 MR. SPEIS:.TheLnext viewgraph says a-few things 10 about'the severe accident program.
We'think the IPE could 11 provide the basis and the framework for an accident management 12 program in addition to input from other areas, which Dr. Murley 13 discussed already.
I have given an example here in the area of 14 following core damage,.what type of things could be in the 15 severe accident program.
The capability of existing systems to 16 arrest or contain in-vessel the consequences of an accident, 17 the capability of existing systems to maintain containment 18 integrity, to assess what is the best way of using such 19-systems, if there is a capability of arresting or containing 3
20 in-vessel the consequences of an accident, how can you make it 21-happen, what type of changes, some hardware changes, or what
]
22 type of procedures or actions are necessary to make those 23 things happen.
24 That is really the heart of the severe accident 25 management program we are talking about.
________________._______________.___w
4' 29
'l COMMISSIONER BERNTHAL:
Does that suggest that1there-2
-still exists a serious question in.the. minds of the: staff,.that-3 Lthese containments in the event'of a core melt accident have a 4
rather high probability of containment?
You say the capability 5:
of existing systems to-arrest and/or contain in-vessel-the 6
' consequences-of an' accident.
7-Is that-still.an open question in the event of a cere.
~
8.
melt. accident,_whether there -- I'm not going to resort to 9
numbers here.
There'have been too many. numbers thrown around..
110 There is a reasonably high probability'of containment' failure?
11-The numbers that happened range from 10.to 90 12 percent, but you' pick your number, but that's a reasonable 13 probability, in my judgment.
14 MR. SFEIS:
Let'me say, as Tom said, the containments 15 were designed for design-base accidents, large-break'LOCAs, l
16 steam line breaks.
Also they were designed'for a large source 17 term, which was cleansed of its pressure and temperature 18 elements, as the Part 100 source term.
I 19 Now in the last ten years, we have done a lot of work-20 to see what type of capabilities the containments have to take 21 the challenges of severe accidents.
Some of them have more, q
l 1
22' some less, okay.
We all know that large drys have more j
l
]
l 23 capabilities than other ones.
I 24 COMMISSIONER BERNTHAL:
Well, what do MARK-Is have.
25 MR. SPEIS:
MARK-Is, the 1150, for example, talks I
.e
y i
30 1
about the probability of containment failure, even though you l
2 don't want to use numbers, ranges anywhere from 10 to 100 3
percent, depending on what assumptions one makes, and those 4
assumptions really go from one extreme to the other.
The 5
depend on the temperature of the corium.
They depend on the j
'u 6
temperature of the -- what is the basemat, whether it's
)
7 limestone or uhether it's basalt,,
whether the temperature of 8
the corium is that of the melting of the uranium or it's closer 9
to the melting of the steel.
10 So these parameters go from one extreme to the other.
11 And the failure can vary from a few hours to many hours, okay, 12 and these are the things that we have to understand more before 13 we say, you know, this particular fix will take care.
We have 14 to have a better feeling.
15 COMMISSIONER BERNTHAL:
But is the -- is Staff not 16 willing at this point -- you tell pc -- is there disagreement 17 at this point that there is a reasonably high probability of 16 early containment failure in the event of core melt for BWR-Is?
19 1 would even call 10 percent a reasonably high 20 probability, and in any case, we're talking here about ten i
21 times higher than for large drys, as you know.
22 And I always have to say in the same breath that I 23 understand that the risk to the public for this class is about 24 the same, because they have a lower core melt probability to 25 begin with.
.e J
31 1
MR. SPEIS:
I think it's fair to put this in 2
perspective.
There are some other containments that other 3
failure modeo have been postulated to lead to early containment 4
failure, and we're trying to come to grips with that.
5 COMMISSIONER BERNTHAL:
Well, but not the large drys.
6 MR. SPEIS:
Well, the ice condenser, for example, 7
okay.
8 COMMISSIONER BERNTHAL:
Yes, I know.
9 MR. SPEIS:
And I don't think --
10 COMMISSIONER BERNTHAL:
That's a separate subject.
11 MR. SPEIS:
So I think we want to look at both the 12 ice condensers in the MARK-Is and the MARK-IIs very carefully, 13 and I don't think our program is one of wait forever, okay.
As 14 I say, you see at the end of the schedule that we have an 15 aggressive program to come to grips with that, but based on the 16 risk and based on the things that are done on a daily basis 17 with these plants, you know, we don't think that --
18 COMMISSIONER BERNTHAL:
But you have no reason to 19 doubt what has been, up to this point -- I won't call it 20 conventional wisdom, at least the wisdom of the last few months 21 if not years, that the BWR MARK-Is have a reasonable 22 probability of early containment failure in the event of a core 23 melt accident, and as apparently do the ice condensers, but 24 that's a separate issue.
25 MR. SPEIS:
Well, that's what the studies are telling
s
.-e 32-3-
1:
us.
E2' COMMISSIONER BERNTHAL:. Well, the: reason I ask the
- 3 question is<that the examples in the severe accident' management l
{
R 14
. program ---for example, the capability.cf. existing systems to -
~
5; maintain containment integrity -
we're' talking.about a
~
'6 capability somewhere within what I take-it Staff agrees'is'an t
7 envelope ofL10.to.-
maybe if not_90, 100 percent failure 8
probability.
9-MR. SPEIS:
But I think.this is kind of a sequence, l
10 you know.
1N;'s'in the' process of going through this effort.:
11 You have to do that, and then one of the items below it.says, 12
'"the benefit of additional devices and specific procedures to i
'13 further enhance'that capability," okay.
14 You have to understand where you are, and then, you 15 know, whether --
16 COMMISSIONER BERNTHAL:
That's exactly what I'm 17 trying.to understand.
18 MR. MURLEY:
Let me add a perspective, if I can.
I 19 haven't been in'this for the last several yoars, really, this 20 detailed analysis, but I'm in the position now of having to 21.
make some judgments.in the' matter, and here's where I see 22 things.
23 There always has been a concern that the MARK-I 24 containments, under severe accidents, core melt accidents, 25 could fail early, and, of course, the Chernobyl accident 1
1
I 33 il
. heightened _that concern.
The Staff looked at it' carefully 2'
_again and came.up'with some proposals that they felt'could.
3 mitigate'that, not totally but were in the right direction.-
)
~
l 4-There's.two things that have happened.since then, as l
1 1
5
'I see it.
First of all, more research.has been done, and when 6
the experts'get'together, the consensus,.such'as there was a' l
7 year ago,_has-evaporated, as near as I can tell.
They'can't --
8 there's some talk about containment failures-in three minutes-9
'or three and;a half minutes after vessel failure.
And in my
-10
. judgment, I"think that's sheer nonsense.- I think common sense 11
.has:just gone;out the window in some cases.
l 12 So we need to reestablish that consensus, as much as
.13 Tna can.
.14 The second thing that at least'I've --
15' COMMISSIONER BERNTHAL:
Tom, could you tell us --
16 just give us a' hint of at least one or two-technical' points of 17 view that have led to the evaporation of that consensus?
18 MR. MURLEY:
Well, there is the phenomenon -- I'll
-19 let Themis address it in more detail -- of direct containment 20-
, heating, for example, which has only come up in the last 21 certain~ time.
22 COMMISSIONER BERNTHAL:
On which there is 23 considerable dispute?
24-MR. MURLEY:
Yes.
25 COMMISSIONER BERNTHAL:
Yes, okay, i
e 34 il MR.'MURLEY:- Within the last year or'so, weLhave 2l learned that.there'is a' great deal'.- :in the TMI-2' vessel, 3
.there is a; great de'al of molten fuelin the. bottom, 20 tons 1or' 4'
'so,Ethat has~ moved around.- If someone'has asked me that many; "5:
. years ago,:would that vessel have-withstood.20 tons of molten:
6 fuelnint there,JI:would have said no.
-7 So I.think'the vessel'itself is probably'more. robust'
~
8 Lthan we had thought.. We don't know theidetails.
I'think it's 9'
essential that we. understand what. happened at TMI-2,'so we can.
10
. develop _our models better, and'in particular the. capability'of 2
11 the vessel itself.to hold up some molten fuel.
12.
COMMISSIONER BERNTHAL:
But the vessel does not 13 address the question of defense-in-depth, unfortunately.
14 MR. MURLEY:
Well,'I view the vessel as.part of.the 15 containment integrity.
Yes, I do.
And defense-in-depth really 16 comes into after the core is melting and molten.
Now.how do.
17 you protect the public?
18
.And I view the containment -- I mean, the vessel --
- 19 as part of the containment system.
And I think it needs more 20-research.
21 So this evaporation of the consensus, so to speak, 22 is,.to my mind, the key -- and as I. talk with Harold and read 23 where he'came out at the end, I think that's kind of where he 24 came out as well, that where the proposed fixes seemed 25 reasonable, and no doubt they're in the right direction, L
-c,;:
~~r
-o '.
i:
s 35 y
g 1;
.they're.probably notLgoing to settle the issue, and that's 3
2-where:I'm'at:today..
v 3'
so'I'think we.need.aLcomprehensive program.to really--
4 settle'it,.even-if it's down the' road a ways.
5-COMMISSIONER BERNTHAL:
-I would just say one thing.
6 I' don't'disagreenthat defense-in-depth:means core integrity, 17 vessel integrity, and ultimately'something'aroundJthe, vessel.
8 We have not really confronted that: issue,:though, as 9
- a. matter of policy here.
Whether and what point'the Commission' 10; is prepared to back off to a very lightweight, for want of.a 11-
'better word, or even no containment, as'in the case of Fort'St..
12 Vrain, because we feel that the core'and/or the vessel have_a.
13 very high degree of integrity --
14 MR. MURLEY:
No, I would not advocate that.
But I do 15 advocate, Commissioner, that we treat the vessel as'-
.we can't 11 6 assume it away in our calculations.
That is, it has to be part 17 of the time of-failure and whether, in fact, the containment 18 can be attacked so vigorously.
19 COMMISSIONER BERNTHAL:
Isn't that a' factor in 20 whether the containment fails because of:the time, is what i
21i you're saying?
L:
22 MR. MURLEY:
Yes.
23-COMMISSIONER BERNTHAL:
Okay.
24 MR. BECKJORD:
Tom, just one point which I'd like to 25 emphasize.
The studies of risk and failure and large release L'
l 36 1
are, as you well know, based on probablistic risk assessments, 2
and as that technology has developed, the approach has been to 3
assume either that operators would take no action -- that is to 4
say, the accident would be hands-off or, in fact, if they had a 5
choice, they would take an incorrect action, which would" lead 6
to further difficulties -- and I think this was done in the 7
early days to ensure that the risk assessment was comprehensive 8
and took, if anything, a pessimistic outlook, and the idea of 9
the accident management here, I think, is a further development 10 which considers what has actually happened in reactor.
11 accidents, in which actions at TMI and Browns Ferry and other 12 actions, operator actions, were, in fact, although errors were 13 made, also some very important corrective actions were taken 14 which led to the outcomes which were not severe, as far as the 15 public is concerned.
16 COMMISSIONER BERNTHAL:
Well, I just don't want to 17 leave the impression that the Commission is backing away from 18 the principle that the containment should be another barrier in 19 the defense-in-depth concept, that I think what Tom is saying 20 here is that --
21 MR. BECKJORD:
- Right, l
22 COMMISSIONER BERNTHAL:
Because of the possibility of 23 a slower vessel failure that -- I gather that you feel that the 24 possibility exists that the containment might turn out to be 25 more resilient against failure, not because it's stronger than s
4 "
37.
.j
.x 1
'we thought, but because the.challengelmight be less than we 2
thought.
3
'MR. MURLEY:
Exactly.
4
~ COMMISSIONER'BERNTHAL:
That's the. message,'right?:
5
,10R. ' SPEIS :
Yes.
. :Mr. Bernthal, this again, you know, 6'
. assessing the capability,'if.that's true, okay,'this is part:of I
e 7
the program, if the. postulate is true, to assess -- toLlook at 8.
that, 'not..to just dismiss the vessel, you know.
9
[ Slide.]'
10 The.next Vu-graph goes.into more detail on:the 11.
containment' performance improvements.
I think we have danced 4
12 around this part during the presentation itself.- Again, I want 13' Lto repeat that the effort-here is to continue in parallel with-14 the IPE and examine very carefully the failure' modes forfeach 15 containment, given=a severe accident; separate the more-16 probable failure modes from the less' probable one, and, of 17 course, that's where the views vary widely.
As. Tom said
'18~
earlier, when WASH-1400 was put together, people made some 19 judgments-that some failure modes were not as important as 20 others..For example, steam explosion was thought to be maybe a 21 factor of 10 or 100 less probable than some overpressurization.
22 So it's important to do that always, because I don't 23 think we can fix every type of containment failure mode that 24 anyone postulates, regardless of its probability.
It just
'25 doesn't make sense.
So that part has to be done.
It's very e
y
'n 38-
]
d 1
. crucial.
j i
2 Getting.to the MARK-I.itself, Commissioner Bernthal'
]
3
. raised 1the questions, the people that have been working in'this
- 4 area have postulated a' number of failure modes.
The ones that.
5 really challenge the' containment are when the corium itself 6
leavec'the vessel and interacts with the cavity itself,-
7 because,.as you know, the suppression pool itself is large 8
enough to kind of render steam spikes,'you know, non-important.
9 Also;the MARK-I containments, as you'know, are inerted with 10 nitrogen, so the hydrogen combustion is not a problem.
So the 11' only. prob 1cm left is the'-- serious problem is-the interaction 12 of the corium-with the concrete.
13 So two or things can happen as a. result of th at,-
14 okay.
One of them, when the. interaction takes place, then the 15-gases that are generated eventually lead to overpressurizing 16 the containment, because that containment has-a smaller volume-17 than the other containments, so it doesn't take long.
18 Now the time that it takes to do that again depends 19 on some key. assumptions that are-made.
What is the cavity, 20 whether it is basalt, whether it is limestone, and also what is 21 the temperature.
22' Now in addition to failing by overpressure, it could 23 also fail by overtemperature, because the gases that are
)
l 241 generated, you know, they are hot, and they could weaken the 25 liner itself.
And so the liner can even fail by
~.,
.- 3 9.
- 1 overtemperature, or it can fail again in:n secondary.way.by 2.
overpressure,'byLreducing its capability to withstand'uore a
3 pressure.
4 As;you know, the liner itself is designed for.
5 somewhere.between 50 and'60 psig,.but'the failure pressure is 6
-much higher than that, fit may be.somewhere between 100 and l
7
- 140.
There may be some MARK-Is more than'that.
8 The'other thing that has been postulated'is that.the coriumitself.canleavethevesselandallofasuddenfind 9-10, itself attacking the liner in a thermal contact 1way.
This is 11 othe'few minutes 1that' Tom discussed earlier.
And we haven't 12 looked at that very carefully, because there is.always a
.13 transportation problem, you know, how far it takes to go, again f
i
- 14 the temperatures and the type of concrete and the composition 15 of the corium.
These are all crucial parameters that we have 16 to'put our hands around.
-17 The proposal itself included five items, if you l
18 recall, and I would say that the two key ones were the sprays 19
.and'the venting itself, and I don't think there is much 20 argument about the venting, except one has to be very careful 21 that both the pluses and the minuses have to be considered 22 carefully, and that's why -- the other problem, we thought, is 23 that the IPE itself, which includes both the prevention and 24 mitigation, is crucial to that, because for some containments 25 there is a stronger coupling between core melt and containment
40 1
failure, especially for BWR containments, for BWR type of 2
plants, so they have to be coupled very carefully.
3 Now going into the sprays themselves, if you recall, 4
the proposal called for utilizing existing hardware, existing 5
systems, to make sure that they can hook up a system that can 6
utilize existing systems that do not depend on outside power.
7 But those systems have a capability of only 10 percent of flow; 8
therefore, the proposal was, okay, let's cut the pipe and let's 9
put a nozzle that can reduce the flow to 10 percent.
And 10 people have raised large questions about that, including the 11 ACRS, whether, you know, cutting the flow to the sprays to 10 12 percent is indeed an improvement, you know.
Maybe others 13 raised the question, you know, maybe we should leave it at 100 14 percent and add some more power equipment.
15 So this area has to be looked at very carefully, 16 because of the scenarios themselves.
I 17 COMMISSIONER BERNTHAL:
I thought that whether it was 18 10, 20 or 25, that the question was whether the minimum amount 19 needed to prevent core melt.
Are you suggesting that 10 20 percent nozzle capacity is inadequate?
l 21 MR. SPEIS:
The technical people who were called to 22 look into these issues questioned that, as well as the ACRS.
I 23 said we had to do more homework.
They raised legitimate 24 questions and they have to be looked at very carefully.
25 COMMISSIONER BERNTHAL:
There is quite a space
- - - - " - - - - - - - - - - - " ^ " - - - - - " - ^ - - - - - - - - - - - - - - - - - - ^ - - - - - - - - - ^ - - - - - ^ - - - - - - -
y 41 JL between 10 and1100.
Are they questioning it could be 2'
significantly reduced?
I always_ thought personally, and I'm 3
not the engineer, I always thought it was a nice back-up to-4 have that capability for an external hook-up.
Why wouldn't we 5
go ahead and do that?
6 MR. SPEIS:
I think we all agree that availability 7
of water is important because you cen cool the gases, you can 8
condense and also maybe you can prevent the spread of corium.
9 The scientists said, well, you have to initiate the sprays, 10 even before the corium leaves the vessel.
They said maybe 10 11 percent is not enough, maybe we need 50 percent.
12 If you recall, the proposal itself is very specific.
13 It was more than criteria.
The industry -- maybe Tom can say -
14 15 MR. MURLEY:
There are two points I would make here.
16 One is that we are going to be faced with looking at some 17 details fairly soon because both the Pilgrim plant and Vermont
{
18 Yankee have voluntarily taken these initiatives.
19 COMMISSIONER BERNTHAL:
I'm quite aware of that.
I 20 was going to ask, why is it they are going ahead and.we are so 21-uncertain about whether it makes any sense.
22 MR. MURLEY:
They foresaw the need, I think, last i
1 23 year, in the wake of Chernobyl, to improve their containments.
i 24 I guess they agreed with the staff in a sense that these J
25 improvements were in the right direction.
I'm quite sure tiiey
)
42 1
did not know the details at the time, the benefits, but now 2
they have gone through the engineering and we are starting now 3
to have something in front of us that we can really look at.
4 There are some side effects to these so-called 5
improvements.
If one has a containment spray that is too 6
large, for example, there may be other sequences, not a core i
7 melt sequence, but other sequences where if the spray were to 8
come on, it would draw the pressure down too great and draw a 9
vacuum.
10 COMMISSIONER BERNTHAL:
Too large?
11 MR. MURLEY:
Where the spray could be too large; yes.
12 COMMISSIONER BERNTHAL:
The question was making it 13 smaller, I thought.
14 MR. MURLEY:
That's what I mean.
There are all of 15 these considerations that one has to take into account.
Now we 16 are --
17 COMMISSIONER BERNTHAL:
That's not a new problem.
I 18 What they are doing, if anything, fixes that new problem if j
19 indeed it exists, by making the spray smaller.
That is not a 20 new question that would divert them from the course they were 1
1 21 taking.
22 MR. SPEIS:
People have raised questions about the 23 adequacy if they make them too small also.
One has to look at 24 the pluses and minuses of the 100 percent or 50 percent or 10 25 percent.
I think as Tom is saying, in front of us, we will
a--
l; 43 1
{have veryJsoon two detailed evaluations,1from Pilgrim and:
~
2 Vermont Yankee, that will: help us in the process._of trying-to
'3 xunderstand.this; issue better.-
n 4,
COMMISSIONER BERNTHAL:- They have'not. reached a 5
conclusion ~at Pilgrim or Vermont on the issue'of.the spray 6.
nozzle. capability?.
7 MR. MURLEY:
To tell'you the truth,'I don't.know~
- We 8.
just got a submittal from'them this week,-from' Pilgrim,7that we-9
'are going'to:look~at in detail.
The. staff is-going to be 10-sitting. down with ^ their engineering staff and' looking :over. the 11 details.
That'will' help us with the generic question as well'.
12 MR. SPEIS:
On'this viewgraph, all of this 13' information'will be utilized.
Also, in the next few weeks we.
14 will be looking very carefully at what short term analyses or-15 research could be done in some of these areas, to'get a better 16 handle.
17 COMMISSIONER BERNTHAL:
Themis, I'm sorry to 18 interrupt again.
On point number one, that'all sounds good 19-except that I assume that folded into your improvement 20 schedule, there is a schedule of some kind implied there with
-21 our setting priorities.
I'm talking about priorities.
I
'22 wanted to talk about containment improvements.
I trust we are 23 looking at Mark I's before we are talking about large drys.
24 MR. SPEIS:
The priorities will be Mark-I's and ice 25 condensers; yes.
.._-__._______m__.___m__________.__________
44 1
1
-[ Slide.]
l 2.
MR. SPEISi-The next viewgraph discusses a schedule.
3 The IPE process, we have met with ACRS.
We have a letter.
We l
4 think the letter is' basically giving us the green light, 5
assuming we take some. advice into account.
I' mentioned the 6
advica'when we had the exchange on the wrong letters.
7 The ACRS told us to tune up our guidance on 8
containment performance improvements and also possibly get some
'I l
9 volunteers to do this effort and'then learn from that before 10 you give.the green light to everybody in a massive way.
H 11 As you see here, the schedule calls to hopefully get' 12 the letter.out this year.
I think we will try to meet or 13 improve on this date that I have listed here, 12/1.
.l 14 (Slide.)
I 15 MR. SPEIS:
Hopefully, the letter will say that the 16 utilities will tell us what methods and what schedules they 17 plan to use next year.
At this point in time, we visualize the 18 completion date is expected to be around 1990, and possibly 19 many plants or a few plants may have finished implementation of 20 those fixes.
21 I have a parallel schedule that talks about the 22 containment performance improvements.
This is in parallel with 23 the effort and the focus initially will be on the containments, 24 that the analysis shows more vulnerable to severe accidents.
25 The next page talks about making recommendations to
+
45 1
the Commission next August.
2 That's basically our schedule.
It lists all the 3
things incJm*.ing the review of the plant specific efforts that 4
are underway.
NUMARC has committed to do a study of all 5'
containments.
They promised this report would be before us at 6
the end of August.
We will be discussing these things with the 7
ACRS.
8 MR. BECKJORD:
I think that is Mark I's.
9 MR. SPEIS:
Mark I's.
In the next few weeks, we will 10 make sure that we pinpoint as precisely as we can what are the 11 areas where the views are wide and undertake any additional 12 analysis or experiments and get all these people together in a 13 room.
That process has to go on.
As I said, and I am 14 repeating myself, we will have recommendations to you next 15 summer.
16 COMMISSIONER BERNTRAL:
Could somebody review for us 17 quickly what we have done in the last eight months here?
Could 18 you give us a quick sequence of events?
The Commission met on 19 this last November, early November.
What exactly have we done 20 in the last eight months?
21 MR. SPEIS:
Let's see if I recall all the things.
22 Maybe Jerry Holman can help me.
We met with the Commission.
23 We met with the ACRS.
We met with the CRGR.
We called 24 meetings and prepared for those meetings very carefully with 25 the laboratory and university scientists.
Those meetings took
[_
46 1
place'in March.
2 We had a detailed technical agenda.
We spent two 3
days discussing the issues and listening to the different 4-views.
5 At that meeting, it was strictly us and the 6
laboratory and university scientists.
A month later, we met 7
with the industry people and their scientists.
Unfortunately, H
8 like everything else in this world, the views there were also 9
different than ours.
We have to not only get the views of our 1
10 people together, but we have to very carefully consider what 11 other people are saying.
12 The bottom line really is, as Tom said and WASH-1400 13 said, if Mark-I fails, it is at a probability of 100 percent, 14 NUREG-1150 says somewhere between 10 and 100, the IDCOR people 15 say it is somewhere between 10 and 20 percent.
Some individual 16 utilities say it is less than 10 percent.
17 We will make a decision, there is no question about 18 it, and we will tell you what it is and what is the basis.
You j
)
19 really have to understand where everybody is coming from.
1 l
20 COMMISSIONER BERNTHAL:
How many meetings with ACRS 21 have you had?
I 22 MR. SPEIS:
Just one meeting.
That was on Mark I.
I 23 That was 12/9/86.
We met with the ACRS twice this year on the 24 IPE and the generic issues also came up.
We had two full day 25 meetings with ACRS.
They did write a letter on the IPE.
1
_._________J
47:
1' MR. MURLEY:
Commissioner, I think I'know one'of the 2'
things that is troubling'you and that is a year ago or six 3
months-ago, the staff seemed quite certain that it knew exactly t, '
what'needed to be done to solve the problem of Mark I.
At~
'5 least,Jthat is how: I read things last year.-
There have-been Li 6
some' intervening discussions, studies and analyses.'-
i 7
I personally am less confident that.these proposed
'8' fixes would resolve the issue.
If I were confident they would-9 resolve the severe accident issue for Mark I's, I would say 10-let'sLgo ahead and do it.
I'm not.
I think we would'be'
'll sitting here a few years from now debating other things to do.
'l 12 It is for that reason that I-recommended to Vic that 13 we put together a comprehensive program that contains all the 14 ingredients for closure to this issue.
We don't have'it 15 totally scoped out in terms of all the tasks and all tNa 16 schedules.
I'm pretty confident that all'the-ingredients are 17 there, that we can say once we have done these things, this 18 issue is behind us.
19 It will involve no doubt some improvements to plante, 20 no doubt it will involve sono improvements to BRW Mark I's and 21' perhaps ice condensers.
Right today, I would say we are not as 22 confident as the staff was a year ago, that these are the 23 things that need to be done.
24 COMMISSIONER BERNTHAL:
I don't disagree that one 25 doesn't want to rush into things.
I don't think the question
9 44
]-
j m
As 48-
' 1'..
.'iis whether~we~'are. going to resolveyall thefproblems.that anyone-
'i
,. w-2
.ever thought.of that might exist for'any_ reactor,(including'the
~
3-Mark 1I.
The? real question. it seems1to me 'is whether 'the steps r.
j-
-4
- proposed willihelpiand whether they are cost} effective.
I'm a a
'5' little concerned 1that we not waitiforithe final-and~ ultimate-y L
6-solution to'all conceivable problems to'the Mark'I.when we may:
~
f L7
.have in. hand stepsJthat'one,'could be cost effective,;and 81
. secondly,2will' help.-
U se 9
LILwould just urge that wefkeep those' points-in mind j
~
10 astvefproceed.:
~ 11 y'MR.:MURLEY:
I should say there.is^not; agreement.on-12 those two, answers to those two questions today, in my
'13-judgment.
I mean a consensus.
1
- 14 -
Well, Mr. Chairman, that summarizes and concludes our
.15, presentation:% and we'll be glad to answer any more questions.
16 CHAIRMAN ZECHO All'right.
Thank you very much.
g..
17 Are there other questions from my fellow 18 Commissioners?
Commissioner Roberts?
19 COMMISSIONER ROBERTS:
No.
20 CHAIRMAN ZECH:. Commissioner Bernthal?
21' COMMISSIONER BERNTHAL:
Well, I've asked so many 22 already, I'll give you some opportunity.
I do have a couple 23 more here, but I've interrupted so often, maybe someone else 24 should have a shot.
25 CHAIRMAN ZECH:
Go ahead, if you have others.
Please
q 49.
a TIL proceed'.
]
I 2J COMMISSIONER BERNTHAL:
Well, you may get tired of j
3 listeningzto this.
4 One or two questions.
First of all, I'd like:to go
~
15' back to the fact, as you pointed out, Tom,Ethat we've got two 6:
utilities'now that are looking very seriously and very, 7
carefully at the fixes that were recommendedElast year.
8 Can you update me, to the extent possible,~or have we
'5F simply -- do we not know what's going on up there?,. What broad 10 conclusion have they reached?
Have-th'ey decided-that although-11 they may not solve all of the problems, that these are cost-12 effective and worthwhile fixes, if they're going to go ahead?
13 KR. MURLEY:
We have reviewed in a general way with 14 both Boston Edison and Vermont Yankee that proposed 15 enhancements.
They call them safety enhancement.
As they got 16 into their programs last summer, at least when I was up 17 visiting-the plants, they were concluding, it seemed, that more 18 of their resources ought to go into preventing the accident in 19 the first place.
So even though they started off as 20 containment enhancement measures, frequently they led to things 21.
like improving electrical power supplies, improving water 22 supplies to containment spray, in order to prevent the core 23-melt accident in the first place.
2<
We have asked each of them to provide us now with the 25 details of what they're doing, as they're getting ready to i
L 1.
'50 o.'
1 implement the improvements.. We have just this' week received I e -' / -
H l
2 from Boston Edison, for example, their package of what they're j
l 3'
' proposing.
Staff'has'not reviewed.it yet, so'in the next --
4 well, this month, in the next few weeks, we're going to be i
5 reviewing the details for both plants.
[
t 6
COMMISSIONER BERNTHAL:
Where would.we be today if I
7 they had not'gone ahead with their: programs?L That wasn't our
.8 idea.
j 9
MR. MURLEY:
Where would we be?
10 COMMISSIONER BERNTHAL:
I.mean, I'll grant you that f
11 it'seems:to'me a stroke of. good fortune in a.way that two 12 utilities have simply'gone ahesd and proceeded, as I understand 13 it, with a fairly detailed plant evaluation to determine the
' 14 effectiveness of these proposals that were made a year ago.
11 5 MR. MURLEY:
Yes.
And that's since --
16 COMMISSIONER BERNTHAL:
And where would we be without 17 those at this point?
It's hypothetical, but I'm curious.
18 MR. MURLEY:
We clearly would not have as much 19 engineering information that they have developed, if they 20.
hadn't gone ahead.
And so we'd probably be even more 21 speculative than we are today.
22 COMMISSIONER BERNTHAL:
So we are finding that very 23 useful, though, to our analysis and attack on the problem, I 24 take it.
25 MR. MURLEY:
I believe so.
u:..
L-
.j
'51 -
f, m
11 COMMISSIONER BERNTHAL:
Could'we have do'neithat a.
o,
2-
- year lago on our own?
o/<
'3 MR. MURLEY:
We could have. required'a year ago that J4
'all plants do this, but we-could not, I don't think, develop-l 5
the kind of engineering detail and analysis, for example,-that 1
g 6
Boston Edison hasEdone.
7 They are also, by the way, finding it's costing far.
,8-
.more than they had expected a year ago to implement these-9 things.
' 10 -
' COMMISSIONER BERNTHAL:
Do you have a:4 estimate of-h 11-the costs?
12 MR. MURLEY:
I don't, no.
But the'last numbers --
13 well, I shouldn't even mention them, but they're in the tens of-14 millions as opposed to a couple million.
15o COMMISSIONER BERNTHAL:
Millions, okay.
16 COMMISSIONER ROBERTS:
Did they do that in house?,
17 MR. MURLEY:
Yes.
18 COMMISSIONER ROBERTS:
They did?
19 MR. MURLEY:
They have & large number of consultants 1
4 20 in specialty areas, Commissioner, like the IDCOR technical
-l 21 people, but the engineering itself, they have a very good 22
. engineering staff.
23-COMMISSIONER BERNTHAL:
I'm also interested in 24 hearing.-- I don't want this to be too long; we'll run out of 25 time -- but could we go through each of those five fixes that
o-52 1
had been proposed?
Could you give us just a very, very brief, 2
please, thumbnail on what the status is, the current _ view of 3
disagreement or agreement on the' validity of those fixes?
i 4
MR. SPEIS:
Yes, I can do that.
5 MR. MURLEY:
We could put the chart up of the five 6
improvements, so that the audience can see it as well.
7 MR. SPEIS:
Can you put the backup Vu-graphs that 8
address the range of views?
Is that what you are asking, l
l 9
Commissioner, basically?
10
[ Slide.]
11 COMMISSIONER BERNTHAL:
No.
I think if we reverse 12 it, I can see if it's what I want.
l 13 CHAIRMAN ZECH:
Reverse the slide, please.
14 MR. SPEIS:
Reverse the slide.
15 Well, let's start with the first one, hydrogen 16 control.
The objective there was to reduce the likelihood of 17 hydrogen burn that could threaten the containment integrity, 18 and the proposal, really all it was, at present a MARK-II stays 19 non-inerted for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
So it was to reduce that to 12 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />, so that was the -- to reduce to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
21 The consensis was that it provided very little risk 22 reduction, you know.
That was the consensus, okay.
That was 23 very simple, okay.
24 The drywell sprays was to provide the backup water 25 supply without AC independent power, as we talked about it, and
53 1
1 again was to utilize existing water supplies and equipment to I
2 deliver water to the drywell, but that capability was at lower 3
flow, and therefore, you know, the proposal called for 4
redesigning the nozzle.itself to deliver only 10 percent of the 3
l 5
flow, okay.
6 People have raised questions.
We discussed some of them, including the ACRS, whether you really will be able to 7
8 prevent the corium from attacking the liner itself, okay.
9 COMMISSIONER BERNTHAL:
I think we've beaten that one 10 fairly well.
11 MR. SPEIS:
Pressure control, the only questions that 12 were raised were to make sure that a very careful look is given 13 at the pluses and minuses, you know, make sure that you don't 14 rig up some system that will go by the control room and 15 challenge the people who are trying to man the plant during a 16 severe accident.
17 Also if one is not careful -- I think Tom mentioned 18 this -- it could advercely impact the -- provide cavitation to i
19 the low-pressure injection pumps, you know, and that could lead 20 to a core melt, you know.
So premature depressurization, 21' creating a vacuum, but I'm not saying that that's not -- that 22 cannot be overcome.
A lot of points were discussed, that one 23 has to be very careful in looking at the pluses and minuses, 24 you know.
25 MR. MURLEY:
There's a very sticky policy point in l
~-
- q; 54 1
1 this..This11s not.an. automatic vent --Ethat is,.like in the 2
European systems, as'I understand it, where there is a. pressure 3
thing that's automatic.
4' So this means that the operators have to decide to 5
vent.
Now that means venting maybe millions of curies of noble f
6 gases into the atmosphere deliberately on the basis that you 7
may.save a worse accident later on.
This gets state 8
authorities involved and would get the NRC involved.
9 So.the writing of the procedures of how to implement 10 this venting is very sticky, and it's not done yet.
11 COMMISSIONER BERNTHAL:
Very sticky.
l 12 MR. MURLEY:
Yes.
The Governors of the states, I 13 mean their staffs are involved in this matter..
So they're not 14 simple matters to grapple with.
15 MR. SPEIS:
We are following very carefully what the 16 foreigners are doing, especially the Swedes, in backfitting 17 their boilers with this.
18 COMMISSIONER BERNTHAL:
Nevertheless, if you reach a 19 point in an accident sequence where you're saying 90 percent 20 that I'm going to pop the containment, if I vent, I only get 10 21 percent of the release that I would get if I do pop the 22 containment, it's pratty clear that you'd like to have the 1
23 option of venting.
J 24 MR. EURLEY:
Yes.
If one were in or had that kind of 25 certainty, he'd like to have that option.
My experience has
j
.n 55-1 1
been thatLthese are'very murky' circumstances,-and you generally l
2
~ don't know.what's going on with that kind of accuracy, so 3
there's a lot of judgment involved.
a
'4 COMMISSIONER BERNTHAL:
The bottom line is, you're l
5 saying that there is still serious doubt, question, uncertainty 6
las to whether. venting capability is even desirable?'
l 7
MR. MURLEY:
Theoretically, it.is desirable.
The j
i 8
practical matters of implementation --
9 COMMISSIONER BERNTHAL:
The question is, how do you 10 do it?
Yes.
)
12 MR. MURLEY:' Yes.
13 CHAIRMAN ZECH:
And how do you control it?
14 COMMISSIONER BERNTHAL:
So at least we've reached the 15 first step.
16 MR. MURLEY:
Yes.
I 17 CHAIRMAN ZECH:
Yes, and how you control it, you
(
18 know, rather than just let it control you.
19 Go ahead.
20 MR. SPElf?
The proposal called for venting through
'21 the suppression pool, so as to take advantage of the scrubbing 22 capability of the water.
j 23 I think one has to know more about the containment i
24 failure mode.
Earlier it had been postulated that the 25 containment would fail at the intersection between the cylinder
56 1,
and'the sphere. 'Some recent calculations indicate that the 2
potential could be -- the failure could take place at'the 3-suppression pool itself.
So that would make a big difference, 4
because if.you fail there, then you still are'able to push the 5
things ~irto the suppression pool itself.
So that's one thing 6
that we will also be looking at.
7 The fourth one was the core debris management.
This
.8 was really to assure that there is water in the torus room i
9 itself, not in the torus.
So this was kind of a defense-in-10 depth.
If the sprays'and the venting -- well, the idea was 11 that both the sprays and the venting will work, and they will 12 prevent the corium from spreading.-
But somehow'if it got.into 13 the suppression pool, into the torus itself, then if somehow 14 the torus failed, let's make sure that'the room itself is 15 closed, so there is soue water in the torus room, and if there 16 is any corium left, then somehow it will be cooled.
17 COMMISSIONER BERNTHAL:
So is that scenario in great 18 dispute today, or where are we?
19 MR. SPEIS:
Well, this is -- it's kind of a -- it's a
{
i 20 very iffy type of thing, okay.
But again, it depends -- you
]
21 know, I think the heart of those five things is the drywell 1
22 sprays and the pressure control, and the other one is kind of J
23 to make sure that you close the door on the torus room.
)
24 The last one is whatever happens out of the first i
\\
25 four, make sure they are included in the procedures and
.e
r
.g
= * ' -
y.
57 1
. training'.
2:
. COMMISSIONER'BERNTHAL:. Thank.' you.
1E One lastl question.
I think we have established'that
-4 we.already have had some assistance.which is fortunate for two 5
-utilities in resolving these issues.
If you were to. sit down-6.
today,,we have a. fairly detailed timetable, and you were to 7'
attempt to carve.out a budget forLthe. resolution ofLthese
- i a:
issues,: putting these on-a fairly -
let's say'as rapid as.
- 9:
possible1 timetable for resolution to the' extent'that is' 10 possible and to the point where you say, yes, at'least this:
11 partial' step helps.and it is cost: affective and we ought'to-do d
12 this' partial step, if we ever reach that' point, would you be' 13 able to do that?
14
'Why wouldn't we want to go to the Congress directly
.q
'15
'in our next budget submittal.and.unlike has bean the practice, 16 say, this is the amount of money that.we need to resolve the 17 questions attached to BWR Mark I containments?
'18 Is that a practical thing to do?
Why wouldn't we 19 want to do something like that?
Are we being money limited?
I 20 think that is another part of that question.
21, MR. BECKJORD:
We are giving a briefing here next l
'22 week on a broader question which is the severe accident program 1
'23 in total, in'which we are going to be discussing the program as 24 it is presently funded and what we now think is going to be 25 required to complete it and essentially answer the regulatory
.T
cm
'N l: ~*
58-
'_l-questions _thatLarise.
M 2:
I.'m not going.to; anticipate that briefingibecause.
~3 that-has been prepared.
J!e have= just: met with the laboratory.
4 contractors for the~1ast couple of days.- We have sharpened our l
5-thoughts on that.
6-I think'we can present you.with an' estimate.
It's-a 7
broader question than the one you. asked.
It's' total.- I think-8 if we narrowed it'to Mark I containments, we might get a 9-narrower.-- not all of the questions that have to be' answered 10-for the Mark I containments would be -- some of the questions 11 would fall out.. I think we would have to look.at it carefully 12 to give you a good answer.
The answer that-we are going _to 13; give you next week is the total program for the entire severe-Ll4 accident effort..
15' MR. SPEIS:
I was going to_say,.as indicated in the.
16 viewgraph I showed earlier,-we have a program in place.
One of 17 the things we will be looking at in the next month or so is-18 have the people who a;te involved in implementing it, trying to 19 decide what actions have to be taken, to look at these precise 20 needs and define them as carefully as possible in terms of 21-additional resources, short term, or additional calculations, 2 2 --
and then equate that to some dollars or some FTEs.
We will be 23 doing that.
That is a must.
i
- 24 We want to make sure that the program itse]f is l
25-either structured to give the answers or maybe fine tune it to 1
)
\\
59 1
provide some short term answers to the precise and specific 2
questions dealing with Mark I or the ice condensers.
That is
)
3 something we will be doing.
4 COMMISSIONER BERNTHAL:
My point, and we have talked 5
about this before, Mr. Chairman, is I would hope that in this 6
year's budget submittal, and I'm not sure it is structured that 7
way, but I have long felt we should be submitting budgets to 8
the Congress which identify mission areas where we have an l
9 urgent need, at the very least do that, and if it impacts the 10 broader program, then they should be identified as special 11 needs.
12 I suspect that the Congress would be rather 13 responsive to that sort of submittal.
I don't know whether 14 this fits neatly into our budget and whether we can carry out 15 things with all deliberate speed here, in a timely way, or 16 whether we in fact may end up being budget limited for 17 resolution of this issue, which has now been very much back in 18 the public eye.
I think we ought to make sure that we make a 19 submittal that ensures we have adequate funding to move as 20 rapidly as possible in resolving these issues.
21 That would be the only point I would leave with you 22 with respect to the budget process.
23 CHAIRMAN ZECH:
We will take a good look at that.
I 24 think it is a good comment that does merit a good hard look at 25 how we put the budget together.
We are still putting it s
'~)
- n u
m""
60>
1 itogetherithis' year for'next year-coming up.
j
- 2.-
Anything else?
3--
' COMMISSIONER BERNTHAL:
I think:that.is all.. -Thank' I
]
'4 you'very much.
l I
5.
MR..MURLEY:
Mr. Chairman, we' intend-to proceed to 1
4 6
develop this comprehensive program and' implement-it.
We would, 17 of course, always welcome Commission guidance or your thoughts-8' along these lines.
9 CHAIRMAN ZECH:- Thank.you1very.much.
I think we have 10 covered the subject: fairly well today.
I thank the staff for a 11-very informative presentation.
I.think the approach you are
)
12 taking to assess possible improvements of the safety of' Mark t
13 I's~and other plants which we are going to hear about.next ti 14 week, certainly. sounds reasonable to me.
~
g 1
o15 We are anxious to' move ahead.
I would say if.your 16-schedule could be speeded up that'you'have given us, I think it 17 would be the thing to do.
I certainly agree that the things 18 you have learned in the past few months and from other groups 19 are very important and we should not rush in and do something
,20 that could perhaps detract from safety rather than enhance 21, safety, which is of course what we-are trying to do.
22 I would encourage you to continue your association j
j 23 with the ACRS in this regard and also the laboratories, the j
)
24.
industry groups, NUMARC, the commitments they have made, the 3
1 25
' universities.
9
___._______________________________U
61
]
1 I think as much consensus as we can arrive at, 4
2 something as important as this, it would be extremely valuable.
3 I would especially ask that you perhaps have another 4
session with ACRS fairly soon to get their views.
They do 5
have, I think, some very valuable recommendations.
l 6
I would recommend that you continue your severe j
7 accident study efforts, as they relate not only to the Mark I's 8
but to other containments.
I think the presentation has been 9
very useful and very valuable.
10 I would ask you to keep the Commission informed if 11 you feel as your schedule develops there is something that does i
12 come up, that the Commission should be aware of or that you 13 need further guidance on, I hope you will bring it to the 14 Commission's attention promptly.
- 15 COMMISSIONER BERNTHAL:
Mr. Chairman, one point in 16 that regard, again, I would like to get back to the question of 17 where one tries to move forward on all fronts, what then is 18 necessarily a slower pace or whether we can target fairly early i
19 on in this process specific, cost effective fixes that 20 significantly assist in reducing the probability of containment 21 failure and/or risk to the public.
22 I would hope, Mr. Chairman, that we can agree that if 23 the staff reaches a point where any one of these proposed fixes 24 or some other modification here meets the criteria as provided I
25 under the Commission's backfit policy, cost effectiveness, a e
i l
_____________________________________D
o 62 1
- reduction in risks, thatfthe staff would not wait-for!all other 2
. issues to-be resolved but whether would step forward quicklyL 3
and'imake that presentation to'the Commission.
l 4
' CHAIRMAN ZECH:
I would certainly support that.- I am.
5-sure all my colleagues would.
Naturally, if,you find something 6
that does come up that is of urgencyEor a fix that you.really;_
7 feel is'important, that you give that priority.
I'would-81 certainly agree with that.
I presume'that is'what you have in q
9 mind.1 10 MR. MURLEY:'
Yes, that is' contemplated, like improved 11 Tech Specs, Mark'I mods, things'that when they.come'to. fruition.
12 and there is'this consensus, we would move' ahead.
13 CHAIRMAN ZECH:
If there is nothing else, we will.
14 stand adjourned.
Thank you very much.
15 (Whereupon, at 11:32 a.m.,
the meeting was 16 adjourned.)
17 1
18 l
19 20 21 22 23 24 12 5 1
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2
~REPORTERSS CERTIFICATE l
3 1
4' This.is to certify that the' attached events of a meeting of the'U.S. Nuclear Regulatory Commission, entitled:
5 6
7 TITLE OF MEETING:. Briefing on Containment Performance Implementation a nd I nd i v i dua l Pl a n t Exami n.a.ti o n ' (I P E ) E f f o'rts 8
PLACE OF MEETING:
Washington,_D.C.
9 DATE OF MEETING: Wednesday, July 15, 1987 10 11 were held as harmin appears, and that this is the original
-12 transcript thereof for the-file of the Commission taken-
..[
13 stenographically by me, thereafter reduced to typewriting.by 14 me or under the direction of the court reporting company, and:
15 that the transcript is a true and accurate record of'the 16 foregoing events.
17 18 a-----------------
Suzanne Q, Young
. 19 20 21 22 Ann Riley & Associates, Ltd.
23 24
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COMMISSION BRIEFlfiG 0F STATUS OF CONTAINMENT PEPFORf1ANCE IMPROVEMENTS AND 1ppiv10UAL PLANT EXAMINATI0f' (IPE) EFF0FTS T. E. FURLEY, X27691 T
P. SPEls, X27517 JULY 15, 1987
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1 BRIEFIIM OUTLINE OVEPYlEW PROPOSED APPROACF TO SEVERE ACCIDENT ISSL'ES l
STATUS C-F MARK-l PROPOSAL INDIVIDUAL PLAT,'T EXAMINATION (IPE)
OBJECTIVE AND SCCPE IFE INITIATict GEFERIC LETTER GUIDELINES AND CRITERIA SEVERE ACC! DENT mat'AGEMENT PFeGPAP CONTAINt1ENT PERFORhAt CE SCHEDULE
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INDIVIDUAL! PLANT. EXAMINATIONS-CONTAINMENT PERFORMAllCE'IMPROVEf' EFTS i
SEVERE ACCIDEPT MANAGEMENT PROGRAM
'C0fiE! STENT WITH SEVERE. ACCIDFNT POLICY
!8/8/P5:
50FR3213El
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PURS_UE ! IMPROVEMENTS IllVCLVING BOTP PARDWARE AND A WAY WPICH lMPROVES THE' 0VERALL PLAfiT SAFETY AND-RED I f.:
THE-. RISK TO THE HEALTH Af!D SAFETY Of TFE PUBLIC'
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I PPfPOSED IMPROVEMENTS FOP FARK-I C0f!TAINMENTS HYDROGEN CONTRC1 DRYWELL SPRAYS PRESEUPE CCHTROL (CONTAINMENT VENTING) l CORE DEFFIS MANAGEMENT PROCEDURES AND TRAINING
INDIV!fUAL PLANT EXAMINATIONS (IPES)
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4 OBJECiVES AND SCOPE A SYSTEMATIC EXAMINATION OF PLANT DESIGt, OPERATION, l
Mall 1TENANCE AFD EMERGENCY CPERATION; TO BE PERFORMED USING IDCOR'S IPE METHODOLOGY OR A MODERN PRA, IDENTIFY PLANT-SPECIFIC VULNERABILITIES * (DESIGt! AND PROCEDURAL) TO SEVERE ACCIDENTS (FOR ECTP CORE DAMAGE AND CONTAINMENT PFPFCRMANCE).
lit:DERSTAt!D WHAT COULD PCSCIBLY GO WFONG IN A PLANT.
4 IDENTIFY AND EVALUATE MEANS FOR IMPROVihG PLANT /C0t!TAlhMENT PERFORMANCE (V'A PARDWARE ADD 1110NS/ECTIFICATICNS, ADDITICf'S TO PROCEDURES, TPAINING); INCORPORATE IllTO SEVERE ACCIDENT MANAGEMFNT PROGRAM.
DOMINANT SEVEPE ACCIDENT SEQUENCES FOP THE PLANT 1,
'D GENERIC LETTEP INITI/,TE THE IPE PHASE 1 IDENTIFY SIGNIFICANT SEVERE ACCIDENT SEQUENCES IDENTIFY POTErlTIAL APEAS FOR IMPROVEMENTS ESTABLISH ACCIDENT mat'#GEMENT PROGRAM FHAsE 2 IDENTIFY PLANT SPECIFIC CORRECTIVE ACT10t:(S),
INCLUDING. SEVERE ACCIDENT MANAGEMENT PLANNING THE GENERIC LET1Er, SPECIFIES 3 0FTIONS TF'/T COULD BE UEED TO SATISFY THE EXAMINATION REQUIREMENTS IDCOR IPEh LEVEL ll OR III PP.A OTHER SYSTEMATIC EVALUATIOfi METHOD e
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M bOIDELINES AND'CFlitflA GUIDELINES;1DENTIFY PLANT FEATURES AND OPERATOR ACTIONS
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PREVIOUSLY-FOUND TO BE IMPORTANT TO RISK.
GUIDELINES' HIGHLIGHT POTENTIAL AREAS OF IMPROVEMENT.
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IN VARIOUS' AREAS OF PLANT DESIGfs AND OPERATION..
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. CRITERIA ARE.THE APPROPRIATE STANDARDS FOR ASSESSING PERFORMANCE.OF SPECIFIC PLANT FEATURES.OR OPERATOR ACTIONS IDENTIFIED IN'THE GUIDELINES.
-FOR EXAMPLE THE CRITERIA ADDRESS SUCH THINGS AS:
-EQUIPMENT CAPABILITIES, CAPACITIES, AND DURATION OF OPERABILITY-
-IDENTIFICATION OF IMPORTANT OPERATOR ACTIONS PARAMETER IDENTIFICATION FOR lNITIATION OF MITIGATING SYSTEMS AND OPERATOR ACTIONS FIVE SETS OF GUIDELINES AND CRITERIA'FOR THE FIVE MAIN CONTAINMENT TYPES IN THE USA; FOR THE MARK-1 CONTAINMENT, FOR. EXAMPLE, THE GUIDELINES AND CRITERIA ACKNOWLEDGE THE IMPORTANCE OF DRYWELL SPRAYS, AND CONTAINMENT VENTING IN l
a REDUCING THE PROBABILITY-OF CONTAINMENT FAILURE.
1
SEVERE'ACCIDEhT MANAGEMENT PROGRAM i
l INSIGHTS DRAWN FROM THE IFE, AND CONTA!NMEf!T PERFORMANCE EFFORTS COULD IDENTIFY:
PROCEDUPES, CORRECTIVE ACTIONS l
(INCLUDING HARDWARE ADDITIONS / MODIFICATIONS)> TRAll: LNG OF THE CFERATORS AND EMERGENCY TEAMS, AND ESSENTIAL INSTRUMENTATION.
FOR EXAMPLE:
THE CAPAEILITY OF EXISTING S'ySTEMS TO ARREST AND/0R CCf:TAIN If<-VESSEL THE CONSEQUENCES CF AN ACCIDENT THE CAPABILITY OF EXISTING SYSTEMS TO MAINTAIN CONTAINMENT INTEGRITY THE BEST WAY OF USING SUCH SYSTEMS THE BENEFIT CF ADDITIONAL DEVICES AMD SPECIFIC PROCEDURES PAVING SUFFICIENT INSTRUMENTATION AND OPERATOR TRAINING TO KNOW WHAT PEMELIAL ACTIONS ARE
/VAILABLE, WHAT STEPS ML'ST BE TAKEN, AND WHAT EQUIPMENT NEED TO FUNCT10l!
THE INSIGHTS GAINED FRCM THE.ABOVE WCULD BE FACTORED INTO THE PLANT'S DESIGN AND CPERATIONS AND INTO THE SEVERE ACCIDENT MANAGEMENT PROGRAM
3 CUNI A1NMENT PERFORf'il,NCE/!FPh0VEf.ENTS PROCEED TO EVALUATE POTEtiTIAL CONTAINMENT PERFORMANCE IMPROVEMENTS FOR ALL CONTAINMENT TYPES (MARK-I, -!!, -III, ICE CCND. 8 LARGE DRYS).
PROCEED WITH WELL FOCUSED RESEARCH Oil BOTH BROAD AREAS AS WELL AS ON ISSUES RELATING TO SPECIFIC CONTAINMENT FAILURE MDDES AND ASSOCIATED POTENTIAL FIXES TO IMPROVE THEIR PERFORMANCE.
C00RDitATE WITH IPE ACTIVITIES.
IfilTIATE RECOMMENDATIONS TO THE COMMISSION ON CONTAINMENT PERFORMANCE ACT10f15 IN AUGUST 1988. -
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c 6/05/87 (c) iACRS Futt CCMMITTEE.
6/09/87 (C)
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.FFVISE.IPE PACKAGE TO CCNSIDER 1CES. VIEW 51 MEET WITH IPDUSTRY 7/30/87 g"
8/30/87 L
J FRR. REVIEW'0F IPE PAQKAGE CRGR REVIEW OF IPE PACKAGE 10/15/87 e
COMMISSION REVIEW OF IFE PACKAGE 11/15/87
'lSSUE IFE GENERIC LETTER TO UTILITIES 12/01/87 NRR/RES REGIONAL.MTGS TO DISCUSS IPE L
PROCESS 02/01/88 d
UTILITY RESPONSE b
OUARTERLY.F1GS AT NRC HEADCUARTEPS.
L C00PERAT!YF REVIEW 0F SEVERAL FLAPTS
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4 WITH NC PREVIOUS SYSTEMATIC A!!ALYSIS (E.G., g PRA) TO GuiEE THEM THPU THE IPE; USE It:FO TO SHARPEN IFE GulDANCE IPE SUBMITTALS FOR PLANTS WITH 02/01/89 PREVICUS SYSTEMATIC ANALYSES PP0 GRAM COMPLETION DATE EXPECTED BY END-1990 WITH PLANT PROP 0FFD FIXE 9 (IF t,EEDED).
FEF PLANTS MIGHT HAVE CCf'PLETED IMPLEPENTA-TION CF TFCSE FIXES /LEL.
9 11 -
SCHEDULE CONTAINMENT PERFORMANCE /It'PROVEMENTS SET UP FES/NRR STEEFING GRCUF TC COCFDifJATE SEVERE ACCIDEP PRCGRAM l
E/3/87 IMPLEMENTATION 3
ltllT! ATE PEVIEW OF INDUSTRY'S CONTAINMENT 8/30/87 IMPROVEMENTS PROGRAM (NUPARC, UTillllES)
CCCRDINATION W/SEVEPF ACCIDENT RESEARCH PROGRAM TO ASSURE COMPATIBLE EFFORTS /
FFIOPITIEE EETWEEN ThE RESEARCH PROGRAM AND THE IMPLFFENTATIOt? PROGRAM (IPE CONTAINMENT IMPROVEMENTS, ACCIDENT PERIODIC MANAGEMENT)
PROCEED WITH CALCULAT10f!S/WELL FOCUSED RESEARCH Cri SFECIFIC ISSUES RELATItlC TO CONTAINME!!T FAILUPE MCDES AliD POTENTI AL CONTINUING FIXES SEVERE ACCIDErlT IMPLEMENTATION PROGRAM PLAN TO COMMISICN (REV. SECY 86-76); TO INCLUDE IPES, CCt!T AINMENT PERFORMANCE, REGUL ATORY
- --___________-__"------------,____m.
I UTILIZAT10h GF SOURCE TERMS, ACCIDENT MANAGEMENT, IPPPOVED PL ANT OPERATIOf'f, 9/30/87 (HUMAf: F/CTORS) ll TECHNICAL t!TGS W/RESEARCH COMMUff!TY AND INDUSTRY ON CONTAlf4 MENT TECHNICAL ISSUES 10/30/87 STAFF COMPLETES REVIEW OF t'UMARC 12/15/87 SUBMITTAL U/01/88 ACRS, DISCUSS!ONS/ FEEDBACK INITit.L RECOMMENDATIONS TO CRGR Ott CONTAINMENT iPPRCVEMENTS.
THESE RECOMt1ENDAT10NS WILL CONTIf!UE OVER A 2 YE. PERIOD AND FILL COVEP EACH OF THE C0f!TAINMENT TYPES.
WILL BE CLOSELY C00FEINATED WITh THE IPE AND 7/O]/88 THE RELATED PESEARCH EFFCRTS.
8/15/88 RECCPMENDATIONS TO COMMISSION
' - 13 _
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Document Control Desk, 016 Phillips ADVANCED COPY TO:
The Public Document Room DATE:
. l9 b l
FROM:
SECY Correspondence & Records Branch h.
i Attached are copies of a Comission meeting transcript and related meeting l
document (s). They are being forwarded for entry on the Daily Accession List and placement in the Public Document Room. No other distribution is requested or ll!.
required.
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Meeting
Title:
M k r,c bh 1 O %k eT lt w o' l
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of each document, two of each SECY paper.
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C&R Branch files the (-Ninal transcript, with attachments, without SECY
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papers.
3 1
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