ML20151E862
| ML20151E862 | |
| Person / Time | |
|---|---|
| Issue date: | 07/14/1988 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 8807260242 | |
| Download: ML20151E862 (38) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
Title:
PERIODIC BRIEFING BY THE ADVISORY COMMITTEE ON REACTOR SAFEGUARDS Location: ONE WHITE FLINT NORTH, ROCKVILLE, MARYLAND Date:
' THURSDAY, JULY'14, 1988 Pages:
1-33 I
Ann Riley & Associates Court Reporters 1625 i Street, N.W., Suite 921 Washington, D.C. 20006 (202) 293-3950
$0S?k
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.s DISCLAIMER This is;an unofficial tra'nscript of a maeting of the United States Nuclear Regulatory Commission held 7-14-88 in the Commission's office'at One on.
-White Flint North, Rockville, Maryland.
The. meeting was
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open.to public attendance and observation.
This transcript-L has not been rev'iewed, corrected or edited, and it may.
contain inaccuracies.
.The transcript is intended solely for general informational purposes.
As provided by 10 CFR 9.103, it is I
not part bf the formal or informal record of decision of the' matters discussed.
Expressions of' opinion in this transcript do not necessarily reflect final determination or beliefs.
No pleading oor other paper may be filed 'wi th" the' Commission in any proceeding as -the resul-t of,'or addressed ~to, any statement or argument contained h'erein, except:as.the Commission may authorize.
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1 UNITED STATES OF kMERICA 2
NUCLEAR REGULATORY. COMMISSION 3
4 PERIODIC. BRIEFING BY THE ADVISORY COMMITTEE ON 5
REACTOR SAFEGUARDS 6
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7 PUBLIC MEETING j
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I 4
9 Nuclear Regulatory Commission 10 One White Flint North l
11 Rockville, Maryland
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12 13 Thursday, July 14, 1988 14 15 The Commission met in open session, pursuant to
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16 notice, at 2:02 o' clock, p.m.,
the Honorable LANDO W.
- ZECH, I
1 17 Chairman of the Commission, presiding.
3 I
18 COMMISSIONERS PRESENT:
19 LANDO W.
- ZECH, Chairman of the Commission 20 THOMAS M. ROBERTS, Member of the Commission 21 KENNETH CARR, Member of the Commission 22 KENNETH ROGERS, Member of the Commission 23 24 25
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STAFF AND PRESENTERS ~ SEATED AT THE COMMISSION TABLE:
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3 W.
PARLER 4
A. BATES
-5 D. WARD 6-C.
SIESS i
7 W.
KERR 8
H.
LEWIS i
9 C.
MICHELSON I
10 J.
CARROLL f
11 P.
SHEWMON l
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12 C.
WYLIE 13 I
14 i
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16 17 1
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20 1
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24 25 1
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PROCEEDINGS 2
(2:02 p.m.]
1 3
CHAIRMAN ZECH:
Good afternoon, ladies and gentlemen.
f-4 The purpose of today's meeting is for the Advisory. Committee on l j 5
Reactor Safeguards to brief the Commission.on their review of j
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6 the proposed generic letter on Individual Plant Examinations, l i t
7 IPE.
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8 In the-proposed Integrated Safety Assessment Program 9
II, ISAP II, the Commission is scheduled to receive a briefing 10 next week, a week from today, from the staff on the proposed 11 generic letter on IPE's.
Further, the Commission received the 12 paper"on ISAP II, Secy 88.159 dated June 6, 1988 in which the 13 NRC staff proposed not to implement the ISAP II program as a
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14 requirement.
However, the staff would arrange to combine IPE o
j 15 and ISAP's reviews when requested by licensees.
(t, 16 We were informed that this is a matter that the NRC i
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17 staff will a/aress during the workshopL to be held following 18 issuance of the IPE generic letter.
I understand that copies 19 of the ACRS letter of May 10th, 1988, the subject of today's 20 briefing, are available at the entrance of the room.
21 Do any of my fellow Commissioners have any opening 22 comments to make?
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23
[No response.]
24 CHAIRMAN ZECH:
If not, Dr. Kerr, you.may begin, l-25 please.
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4 i'
1 MR. KERR:
Thank you, Mr. Chairman.
We appreciate 2
the opportunity to meet with you.
We have found our meetings 3
with you in the past to be productive.
We are glad to have 4
this opportunity to discuss a topic which we believe is of 5
considerable importance to you and which we take very 6
seriously.
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7 Before beginning our discussion, however, I would
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call attention to the fact that Mr. J.
Carroll, who is a new 9
member of our committee and with whom I believe you have not l
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' met before, is with us today and we are delighted to have him 11 as a member of the committee.
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12 CHAIRMAN ZECH:
Welcome to the'ACRS and to the NRC.
13 We are delighted to have you with us.
14 MR. CARROLL:
Thank you.
15 MR. KERR:
We have asked Mr. Ward to make some 16 opening comments on this topic and then I will expect that 17 other members of the committee will join in with whatever 18 discussion ensues,'so I am going to turn things over to Mr.
19 Ward at this point.
20 CHAIRMAN ZECH:
Thank you very much.
Mr. Ward, you 21 may proceed.
22 MR. WARD:
Thank you very much, Bill.
23 I will discuss the May 10th, 1988 letter, as the 24 Chairman pointed out, but first I'd like to go back a couple i
j 25 months to an earlier -- a short' letter we wrote earlier on f
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1 March 15th, 1988 and this is one where we commented as what we 2
sati as a need for greater coherence among new regulatory j
3 policies.
I'll just quote a couple lines from that and this 4
will explain, I think, why we wrote the letter we did in May, 5
but we pointed out that we saw what we believed to be a lack of 6
coherence and integration among several separate areas of 1.
7 policy making within the NRC.
8 We saw that the severe accident policy was just one i
9 of these but other policies, particularly those which might Itj 10 cause new requirements to be placed on licensees, also were d
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11 part of what we saw as the overall problem of lack of
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12 coherence.
These others included the safety goal and then the 13 approach being taken for the resolution of unresolved safety 14 issues and generic issues.
15 We offered two suggestions at that time and one was 16 that there should be an attempt to integrate all of these j
17 evolving policies and issues and particula'rly any new 18 requirements that would come out of these several different t
l 19 policies or issues, an attempt to integrate those really beyond l'
20 simply the things that had been identified as the severe 21 accident policy issues, but because ultimately the only risk 'in
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- i 22 nuclear power -- this _s slightly simplified perhaps, but the p
23 only risk is from severe accidents so that really all of the 24 regulations and policies of the Agency are directed toward 25 reducing the risk from severe accidents.
It's just sort of a
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6 1
truism.
2 We suggested that there was a need to integrate not' 3
only the severe accident issues but all important technical j
4 regulatory issues.
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3 5
The second point we made in that March' letter was 6
that we saw the safety goal policy as really not just another 7
one of these issues out on the table but we really saw it as j
1 8
the policy which could be a useful tool for providing for 9
integration of all the other policies.
It's sort of an 10 umbrella policy.
11 Those are just some kind of general words to you that 12 may or' may not have been helpful, but then in May we reviewed i
13 two programs which were being developed by the staff and as the 1
14 Chairman mentioned, these were the IPE programs, the Individual j
15 Plant Examination, and the Integrated Safety Assessment ~
16 Program, tha ISAP I.T.
17 We saw in these an opportunity to provide -- by 18 slightly bending around these two policies or developments, we 19 saw an opportunity to provide what we thought would be greater 20 coherence and greater integration for the several, the many 21 policies being developed in the Agency.
So we suggested that 22 taere was some bending around that was needed in our letter of I
23 May 10th and went on and described what we saw as necessary to 24 achieve this.
25 As I said, we really saw this as an opportunity.
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think we weren't the only people who recognized the problem of 2
the perhaps growing or existing lack of coherence among the 3
policies.
I think the staff itself recognized'this and was in 4
fact considering efforts to integrate the severe accident --
5 the so-called severe accident issues.
We were merely 6
suggesting that this attempt at integration should be expanded i
7 beyond just that set of issues.
8 We saw this as an opportunity and, in summary, there 9
are three steps.
We thought that the IPE approach, the 10 Individual Plant Evaluation approach or something like that 11 could be used as a last time around means to identify and
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12 indicate problems primarily in the design hardware at. existing 13 plants, as I say, not only opposite the so-called severe 14 accident set of issues by opposite all outstanding safety 15 related issues, because as I said we think those are all severe
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16 accident issues.
That's the only issue there is, really.
17 Second, we saw an opportunity to use the ISAP, the 18 Integrated Safety Assessment Programs, as the means.to permit 19 licensees to make a coherent, if you will, an integrated 20 response to a lot of different requirement which were coming in 21 from several direntions and permit them to make a response 22 which would be perhaps unique but appropriate for their 23 particular plant designs and set of conditions, but which would 24 be approved, reviewed and approved, by the staff.
25 The third point was that if this was going to be b
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1 done, take advantage of it and expand the concept for IPE and a I
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more universal concept for ISAP.
It looked to us that if bt;
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licensees were really going to do this sort of thing, they 4
needed to have in their hands -- they needed to develop a good 5
Probabilistic Risk Assessment for ths.r own plants to use as a 6
tool in these other two activities.
7 So we made three recommendations and this is in cur 8
letter of May 10th, and I'll discuss these in a slightly k
9 different order than they are given on.page two of that letter, 10 but they're on page two.
Lf' 11 Our first recommendation, and I think it's most j
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f 12 efficient if I can just quote the text.
The purpose we k
13 suggested in this clightly revised program, the purpose of i
14 IPE's would be acknowledged as broader than the original intent 15 of what was called "searching for outliers" relative to severe 16 accident issues, but instead it would call for a general risk i
17 assessment of each plant using the body of experience available i
18 from the TMI-2 accident, from the development from PRA,,from 19 existing severe accident research and really from the general j
20 experience of over a thousand reactor years of operation that
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21 we've had in this country.
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22 Ne would suggest that all outstanding safety issues, t
23 USI's, generic issues would be subsumed by this program and it 24 would be made clear to the licensees that the intent of the 25 program would be that this would be the end of new 9
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1 requirements.
Now that is rather a optimistic view but the l
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intent would be that it would really be the end of new j
requirements except in the advent of important new information-3 4
or new experience, so that given our state of knowledge today-5 it would suggest that'this IPE would bring the plants up to the
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6 best state -- the state they needed to be in based on knowledge 7
today and there would be no further requirements beyond that.
8 The second is the -- actually the third bullet on 9
page two -- and this deals with the ISAP process and this is i
10 really again where the licensees come in, in developing 11 responses to perhaps the several new requirements that would i
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12 come out of the IPE.
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13 We said the conclusions about results of the risk b
14 analysis and necessary changee in actual plant systems and 15 procedures would be determined by the licensee and be reviewed I
16 by the NRC staff through the ISAP process, which has been 17 developed jointly by the staff and certain of the licensees, so 18 we believe that this risk-based approach embodied in ISAP is i
19 the most logical means for resolving most safety issues.
Th'e 20 risk analyses used in the IPE for each plant would be available 21 for use by the licensee and by the NRC staff in their ISAP 22 evaluations.
f 23 Now there is some argument that if the analysis used 24 in the IPE is going to be used for this second purpose, that is
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25 for ISAP, that what's really needed is full scope PRA and not I
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1 just the simplified version of the PRA's which have been l
2 suggested for use in the IPE process that's been proposed.
3 That brings us to the third recommendation, which is 4
the second bollet on page two, second: paragraph from the 5
bottom.
We suggested that each licensee should be required to 6
conduct a substantial and systematic risk analysis for their I
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plant and in fact we recommend that such an analysis would be a I I l
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8 full scope PRA at least to Level 2.
That means at least f
9 through containment performa, ice and that it would, and this is 10 an important addition, and it would include 1oth extern'al and 11 internal initiators, both pipe-breal~s and er.rthquakes in other 12 words.'
13 Now we stated that we acknowle(ge the difficulties 1
14 inherent in making this an immediate requirement.
However, we i,
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15 suggest that it should be possible to develop a phased approach n
16 with the intent that within several yea:;n each plant would have I
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17 been analyzed by state-of-the-art methods, in other words, by a r
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18 full scope PFA.
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1 19 At the beginning, this might very well bi the sort of 1
20 more abbreviated IPE prccess that's been developed by certain 21 places in the industry and with the cooperation of the staff.
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22 Our understanding is that abbreviated IPE process can'be 23 developed' and extended to become a PRA and what we're 24 suggesting is that that should be done and that there should be i
j 25 a commitment that should be done for every plant.
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Actually the staff in its response to this letter has l
2 said in effect well, those are kind of some nice ideas but we 3
are not sure they are practical.
We think they might slow 4
things up, but when we look at the latest draft of the IPE 5
generic letter, it seems to some extent each of these proposals 6
really is incorporated in the draft.
7 First of all, the staff encourages but doesn't
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8 require a full-scope PRA on the part of the licensees and also I
9 and probably as important -- some disagreement here -- they t
10 also say that this PRA at the beginning for the IPE whatever-it 11 is would be only for internal events and that the process for I
12 incorp' orating the threat from external events would come along i
13 later.
14 The draft generic letter on IPE also permits but does 15 not require licensees to taxe initiative in arguing that some 16 of the outstanding USI's or generic issues faced by the plant 17 might be covered by their IPE.
It also permits but does not l
18 require the licensees to take the initiative in providing an i
19 integrated implementation response to new requirements through 20 something like the ISAP process.
In other words, the staff 21 would stand ready to cooperate with the licensee if they wanted 22 to go through the ISAP approach but the staff is not insisting 23 that that be done.
24 In other words, the staff is perma: ting individual 25 licensees to opt for coherence in their response to those l
12 1
several issues and policies, but the staff is not really i
2 explicitly requiring or really providing for licensees to --
I 3
the staff isn't providing the coherence and integration itself, 4
although it is permitting the licensees to respond to new 5
requirements in a more coherent and integrated fashion.
6 Maybe that is good enough but I think that's contrary
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7 to one of the purposes of the policy statement issued a couple 8
years ago on severe accidents regarding future designs in 9
existing plants.
One of the key purposes in that, and I'll 10 quote, was.to "achieve improved stability and predictability of i
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11 reactor regulation in a manner that would merit improved public l
12 confidence in our regulatory decision-making.".
I 13 I guess that's where I have a problem with the 14 approach being taken by the staff.
While they are permitting
'5 the licensees to take a more integrated and coherent approach, c
i 16 they are not clearly telling the licensees that they are in 17 fact encouraging and promising to support this sort of approach 18 in the future.
19 That's all the comments I have at the present time 20 and somebody else might have something to say.
21 MR. KERR:
Any additional comments at this point?
22 (No response.]
I 23 MR. KERR:
There were none to the letter.
24 MR. SIESS:
Which I think might be worth noting.
I 25 j
CHAIRMAN ZECH:
What was that?
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I
13.
1 MR. SIESS:
There were.no additional-comments to the 2
letter.
It may reflect a unanimity or simply a smaller size 3
ACRS.
4 CHAIRMAN ZECH:
All right.
Shall we ask if there are-i 5
questicns or do you want to proceed?
What is your desira?
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6 MR. KERR:
I would like to get any reaction that, you I
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or your colleagues may have to what has occurred so far.
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8 CHAIRMAN ZECH:
Fine. Any questions or comments'from 9
4 9
my colleagues?
Commissior.er Roberts?
3 10 COMMISSIONER ROBERTS:
No.
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11 CHAIRMA?( ZECH:
Ccmmissioner'Carr?
12 COMMISSIONER CARR:
I tend to agree with the apprcach 13 that you're taking.
I think we are inching everybody toward a 14 Level 3 PRA an inch at a time and eventually I'm sure they'll j
15 all get it in time to apply for their license extension but I i
16 think that your points are well taken that they could probably 17 do it in a better fashion.
18 CHAIRMAN ZECH:
Commisstoner Rogers?
19 COMMISSIONER ROGERS:
Well, I don't have much more to 20 add, but it does seem as if urging a PRA on all existing plants 21 does seem to be a wise course and so I tend to be in favor of i
22 that.
I i
23 CHAIRMAN ZECH:
My view would be, frankly, to wait i
24 and hear from the staff next week.
I was frankly hoping'that
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25 ACRS and the staff cc i got together and decide together to a
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1 come up with something that you could jointly agree to, but I 2
guess you've come about as close as you can.
3 Certainly I think that coherence is important.
The 4
staff as I understand, however, is trying to come up with a 5
somewhat similar approach with their master plan to get 6
together on severe accidents and all the other issues that
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7 surround and are part of it.
I 8
I think perhaps we have come closer together as far
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9 as r1gards requiring PRA's.
I certainly do understand and 10 bel.4. eve in the value of the analysis that goes into such an 11 approach.
I guess as far as I'm concerned I'll wait and hear 12 what the staff has to say next week.
I think again that you 13 have come closer together but act quite as I would hope so that 14 the commission would have a joint ACRS/ staff view -- so you've 15 come that close and not any closer, I guess.
16 The Commission will indeed make a decision but I 17 think I want to wait and hear what the staff has to say next 18 week.
19 MR. SIESS:
May I say something?
20 CHAIRMAN ZECH:
Certainly.
I a
21 MR. SIESS:
You know, the IPE I think at the very 22 early stages was going to be "the search for outliers."
Now l
i 23 the' staff has expanded it considerably beyond that and it's 24 quite clear that they have and I think properly.
25 If the IPE ' sere only a search for outliers, it would i
15 I
1 seem to me almoto overkill to use a PRA just to find outliers 2
and then throw the PRA away, so the staff has expanded the uses 3
of the PRA or the IDCOR methodology and not only to find 4
outliers but to handle A-45, to look for accident management --
5 which is coming down theiline -- and so forth.
i 6
They did read our letter beyond the point that said 7
we think it is an improvement over the last one because they 8
made some changes in the IPE letter that I think have gone j
9 quite a few steps toward the thoughts _we have.
j 10 CHAIRMAN ZECH:
I agree.
11 MR. SIESS:
They mention that other USI's or GSI's 12 could"be handled.
I am not sure they could be handled with the 13 IPEM and the IDCOR methodology.
I am sure they could with the
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14 PRA menhcdology because that is what the
- SAP.srogram was.
15 Let me remind you that the severe accident policy j
16 stater 4ent included USI's or GSI'e as a part of the policy 17 stat'/ ment and outliers was another part of it, so resolution or 18 implementation and preferably an integrated implementation of 19 USI's and GSI's is clearly a ' art of the severe accident policy 20 statement.
Now it has been made an adjunct to the IPE, so what 21 we were really tryir.g to say was that the IPE was a part of 22 this.
Let's take a bigger look and put the whole thing 23 together using PRA as a base.
24 CHAIRMAN ZECH:
I understand.
25 MR. SIESS:
Now.whether the IDCOR methodology can 4
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replace a PRA I don't know but we're hanging so many decisions 2
on PRA -- they are just coming up, they're coming up and I 3
don't know whether the plant that has one is going to be at an 4
advantage over the plant that doesn't or vice versa, but maybe 3
4 5
uniformity is what we need.
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6 CHAIRMAN ZECH:
I certainly apprecif;e-those
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comments.
Are there other comments from other members of the 8
committee on this particular subject?
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9 Yes, please go ahead, Bill.
10 MR. KERR:
I believe that there has been a 11 convergence of views between the staff and the committee since 12 the me'etings that led to our May letter.
It has not been 13 complete.
I don't necessarily expect always that it will be I
i 14 because we operate with a different set of constraints than
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15 those with which the staff has to deal.
16 I have been encouraged by what appears to me to be an
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17 effort to achieve greater integration and that I'think is true f
18 not only of the IPE draft version that.we have most recently 19 seen but also as described in the SECY-88-147, which talks 20 about integration of severe accident issues.
21 We have just spent some time this past few days in a 22 subcommittee and this morning in a committee meeting discussing 23 that and we will be sending a report to you indicating some i
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24 comments, but it seems to me almost for tr.e first time we have l
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25 been able, using that document as a base of operations, to
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1 discuss a number of what had been somewhat disparate-issues in 2
a coherent way.
Althour1 there is work to be done and the 1
3 staff I'm sure recognizes this even more than we do, in '
4 integrating at least it represents I think an important initial 5
effort to consider the various things that have grown up from a 6
consideration of severe accident issues and to put them in a
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7 form which permits them to be applied to an individual plant.
i 8
As we recognize, none of this does very much good h
9 until it has some impact on plant design, construction and/or h
I 10 operation.
Chet was making a rsint that the USI?s and generic j
11 issues are importar.L and we agree and although they can be 12 resolv'ed, that is the first step.
There needs to be then 13 implementation.
One of the things that appealed to us I think 14 about the possibility of the ISAP approach is that if a basis 15 existed for this, one would accomplish the implementation of 1
the resolution of these issues along with whatever changes were 16 I
17 necessary as a result of the IPE, i
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18 What we were trying to say was not that we disagreed 19 with the general objectives of 1? hat is going on but that we 1
20 thought given a bit of additional consideration, the process j
21 could be made more efficient and in the long.run more 22 effective.
23 It does seem to me that there is novement in the 24 direction of at least we felt that should occur and I did not 25 detect any great resistance on the part of the staff.
It
18 1
appears to me that one of the things that exists is that they
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have been working on the program for a long time and are 3
somewhat unwilling to completely scuttle it.
I understand
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4 this, and it is a program that I think they were directed to t
5 work on by the Commission, to develop along with the industry 6
an approach that would not necessarily require a PRA.
1 7
At the time this began I think the committee had a 8
feeling that probably such a program should exist.
I believe 9
more and more as we have looked at things we see the lu desirability of a full-scope PRA and I would (Xpect that even 1
11 those plants that may not opt for the full-scope PRA will learn 12 enough'and collect enough information from whatever IPEM that 9
H 13 they may use that they are likely to go ahead and develop the 14 full-scope PRA.
I believe that is a possibility and I 9
15 certainly think it's a desirable approach.
16 CHAIRMAN ZECH:
I certainly am encouraged about the 17 fact that the staff and the ACRS views have converged.
I think 18 they have converged and I think that is very important.
It 19 certainly helps the Commission.
20 I guess maybe you can answer a question for me.
The l
j 21 ISAP program, it is my understanding, is fairly resource-22 intensive and maybe that's the reason that a great number of I
23 utilities have not looked upon it as something that they 24 thought was the right way to go.
I've been under the 25 impression that there are not too many utilities that favor the
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ISAP program.
Perhaps you-could comment on that.
Have you-2 looked into that and what are,your feelings on that?
1 3
MR. SIESS:
Well, it varies.
For example, as I thir:k i
4 you know, there is one utility that was in the pilot ISAP 5'
program with two plants and they've been on their knees before j I 6
the staff begging to have the program extended to their other 7
two plants, so they are extremely enthusiastic.
The staff's-8 questionnaire --
9 CHAIRMAN ZECH:
How about some of the others?
10 MR. SIESS:
The staff's questionnaire got back quite l
11 a f6w people that were interested, but it was not a majority.
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12 MR. WARD:
Twelve percent is what we were' told i
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13 yesterday.
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14 MR. SIESS:
Twelve utilities out of 56 utilities I k
q think is approximately 12 percent of the plants..
15 l L l t 16 The questionnaires that were sent out asked the 1 s 17 question based on the proposal which existed then, which 16 required a license amendment on the agreed-on schedule, which a 19 number objected to.
I don't think any were polled after that 20 was dropped.
21 I don't think all the utilities see a need.
I talked 22 to one of the relatively new plar.ts.
I visited Clinton last h
23 week or the week before and they are not interested in a PRA t
24 and they don't intend to have one and they weren't interested i
25 in ISAP.
I said "Why not?"
"Well, we don't have that many i
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20 1
outstanding issues."
They don't.
They are a brand new plant.
2 I looked at their SIMS report and they didn't have that many.
3 I would like to go back in five years and see how many they've 4
got.
We haven't quit putting new issues out, but a lot of them r
5 object to the license amendment.
A lot of them just thought it' 6
was too much hassle.
7 Let me make a comment about the PRA.
You said that
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8 the staff and ACRS are coming together.
I think the industry 9
is coming arcand.
Perhaps you have read an EPRI report that 10 just came out, a survey made of 10 utilities that had PRA's, 11 how they got into it and what uses they made of them, and they 12 all th'ought they were beneficial, cost beneficial, and I found 13 this quite interesting in view of the fact that the uses made 14 by the various utilities varied tremendously.
Some were hardly 15 using and some were using them extensively, but they all 16 thought they were beneficial not only to their cperation, their 17 reliability but to the health and safety of the public.
18 So I think the industry is coming around.
I think-19 they may need a push.
I thought it had a carrot.
As far as 20 resources, it is going to be demanding on NRC resources.
21 CHAIRMAN ZECH:
Yes.
22 MR. SIESS:
Because a real ISAP approach to all 23 outstanding issues, a risk-based approach which we've used in 24 the SEP on the old plants, said everything didn't have to be 25 done just because it was it was in the standard review plan or I
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21 l
1 1
just because it was imposed.
If a PRA, if a safety analysis i
2 showed that it really did improve things on that plant or if 3
wasn't cost effective or if I fix A it would take care of B or i
4 A we'21d take care of B and C and the project managers in the l
5 SEP had
- 7 negotiate with the technical reviewers in the 6
standard review plan and that's what you'd have with ISAP.
It 7
would be a quite different way of doing business for the staff.
8 There would have to be a lot more judgment exercised, PRA-based i
9 judgment rather than standard review plan based judgment, if it I
l l
1 10 does take judgment to interpret the standard.
h
(
11 It would be a different story but I think it would be
.I i
much m' ore effective.
I think we'd see more things implemented 12 13 in a more timely manner and a more effective manner.
14 COMMISSIONER ROGERS:
If I may ask a question about 15 the PRA experience that you've seen so far, do you have any 16 feeling about who did those PRA's, to what extent the utility 17 staff conducted them and to what extent they were done from the 18 outside?
19 MR. SIESS:
Very little.
Northeast Nuclear -- they l
20 have a 12-man staff doing them.
They do their own.
Consumers' I
l E
21 Power, for example, on Big Rock, they had two of their people 22 from the plant involved in it and that was, they said, one of 23 the great advantages, what they learned about their own plant.
24 Commonwealth Edison's design PRA was done by somebody else.
25 The Byron Braidwood sort of extension, they were replicates of
]
1 22 1
Zion, it was all somebody else's doing.
They are not really 2
into it.
It varies all over the place.
i 3
The ones that have been most involved and not just 4
with a separate PRA group but getting people o';t at each plant y
5 involved both in doing it and using it, they are the ones that 6
have the greatest enthusiasm.
The more they are involved in
~
7 it, the more enthusiastic they are, l
8 It is interesting because Duke has never submitted 9
their PRA's.
They have got them for every plant, three plants.
10 They have never submitted them to NRC for approval.
When they 11 want to use the PRA as an argument on whatever basis, they 1
12 build'their argument on the basis of the PRA and submit the 13 package and let the package stand or fall on its own feet, but 14 they don't cite a previously approved PRA, which would.be very 15 difficult because the PRA is a living document.
If it was 16 approved last year, who knows how good it is this year, but they simply'go back to the PRA as a basis for their analysis, i
17 18 present that to the staff and they have won some interesting 19 arguments according to them.
20 Everybody does it differently.
This report is There are also l'terviews with I think 18 staff 21 fascinating.
n 22 members, NRC staff members, as to what they think about the 23 uses of PRA and that also is quite interesting.
I commend it 24 to you.
I don't have the title off-hand but I could get it for 25 you.
23 1
COMMISSIONER ROGERS:
Thank you.
2 CHAIRMAN ZECH:
Are there any other comments?
3 (No response.]
4 CHAIRMAN ZECH:
Are there other subjects to bring up?
5 MR. MICHELSON:
.I have a related comment to what 6
we're discussing.
In the ACRS letter we pointed out a 7
recommendation that they include both external as well as 8
internal initiators in the PRA.
It is probably appreciated 9
around the table that external initiators at the present tihe 10 are not well handled; in fact, in most of the PRA's they 11 simply are not considered.
12 As to how much of an outlier, how much of a 13 contributor to risk these external events are is really 14 somewhat unknown because of the goodness of the PRA's that have 15 tried to handle the questions so far, so we have asked that i
16 this be looked at carefully.
The staff addressed this in their 17 reply.
They are set'.ing up certein kinds of groups, task i
18 forces to look at the.Tuestions, to come up with some criteria
)
on how we would even hindle external events.
i 19 20 I think this is the right direction to go. The only i
21 comment I would like make on it is that it is a very urgent 22 item in terms of getting it done expeditiously.
The reason 1 23 say this is that we are trying now to review the ABWR.
It is 24 inconceivable that we can give a final FDA on the ABWR withouc 25 the severe accident issue having been thoroughly reviewed and s
.m 24 r
1 taken care of.
[
2 The schedule is going to be very tight to get the 3
severe accident information.
It has to come somewhat in 4
conjunction with the PRA towards the end of the business, but 5
we have to start developing early on the criteria to be used 6
and so forth in an analysis.
Steps are being taken.
I am only
~ _..
7 urging that every effort be made to take them.
8 CHAIRMAN ZECH:
I appreciate your comment.
9 Are there other subjects?
10 MR. SIESS:
Can I ask you a-question?
L 11 CHAIRMAN ZECH:
Yes, certainly.
12 MR. SIESS:
I know the Commission has got a lot of 13 things within your responsibility and a lot of things to worry 14 about besides reactor safety.
You have got waste management 15 and all those nice th!.ngs, but in the area of reactor safety, 16 what issues are there besides sevece accident?
Isn't severe 17 accident the bottom line of reactor safety?
18 CHAIRMAN ZECH:
Certainly that's the important way to 19 look at it.
20 MR. SIESS:
We keep talking about it as if it is 21 something different or separate.
22 CHAIRMAN ZECH:
Our mission is public health and 23 safety and of course severe accidents involve doing what we can 24 to prevent the release of radiation, so clearly that is the 25 purpose of what we're abo.ut -- so that's an understandable way
25 1
to put it.
We don't want to harm the public.
Public health
{
2 and safety is our mission and I think that is what you are l
3 saying, you are alluding to, and I'd agree with you.
s 4
Certainly.
There is no question about that.
l 5
MR. SIESS:
It is not "an" issue in reactor safety,
( !j 6
it is "the" issue, t
7 CHAIRMAN ZECH:
It is the issue.
It is what we're 8
about.
9 MR. SIESS:
I can think of others.
10 CHAIRMAN ZECH:
But this is certainly the focus of 11 our mission and the focus of your mission in advising us in
~
' 12 that regard, so no question about it.
Protection of the public i
13 health and safety is what it is all about, i
14 COMMISSIONER CARR:
I would only comment that I think l
4 15 our mission is more to prevent severe accidents than it is i
16 perhaps to handle.
I 17 MR. SIESS:
Well, you could break the issue down.
If 18 we do not have a severe accident, we're pretty much home free.
19 I could think of some accidents less than what we are calling a 20 severe accident, which incidentally hasn't been defined.
There 21 are some accidents greater than Class 8 accidents that wouldn't h
22 be severe accidents.
If we had a LOCA and a containment leak i
f 23 of 5% we could exceed -- under the worst meteorology we could k
{
24 exceed Part 100 doses, but we wouldn't call that a severe 25 accident.
1 u
j l
26 1
But basically our attention has been focused on 2
severe accidents and it is "the" issue.
I am having trouble 3
finding it as "an" issue in the reactor safety area.
4 CHAIRMAN ZECH:
Oh, I don't think you should have any 5
trouble i'inding it as the issue because it is the issue.
I 6
don't think anybody would disagree with that.
1 7
MR. SIESS:
No, I think what Mr. Carr is saying is j
8 it's involved with prevention as well as mitigation and I
9 certainly we'd all agree with that.
Prevention is --
10 MR. SIESS:
No question about that.
We'd rather have 11 prevention.
~
12 CHAIRMAN ZECH:
Exa'ctly.
13 MR. SIESS:
I hope we never have to mitigate one.
14 CHAIRMAN ZECH:
Right.
I would agree with that.
15 MR. WARD:
That's kind of a truism.
I agree with all 16 truisms.
17 COMMISSIONER CARR:
It is also an emphasis on where 18 you put your budget money.
'ut if you believe in the concept 19 MR. WARD:
Right.
B 20 of defense in depth, that says that you should have means to 21 mitigate an accident in case you weren't really as smart as you 22 thought you were and all the things you did to prevent them 23 didn't work out.
So we believe in defense in depth.
24 Okay, that means that we do have to provide some 25 effort, some technical effort, some resources and construction i
-27 1
and everything else for mitigation if we really believe in 2
defense in depth.
Since we tend to have fixed resources, that 3
means we are going to have to take something away from 4
prevention resources to provide mitigation resources.
5 I don't know what the right balance is, 50 - 50?
90 6
- 107 99 - 17 But there has to be a balance and there have to
~
7 be real resources devoted to mitigation if we believe in 8
defense in depth.
9 Too often I hear when someone starts coming in saying 10 grs, we've got to worry and do something about mitigation and 11 they tend to get written off because no, let's just concentrate 12 on pre'vention --
13 MR. SIESS:
But it isn't that simple.
We put water 14 in the containment to mitigate the consequences of a LOCA and i
15 to keep the steam from blowing up the containment.
We put a i
16 containmont there that mitigates the consequences of a core 17 melt that lets a lot of activity into the containment.
We have 18 emergency plans to mitigate the consequences of a containment i
19 failure, so I could draw a whole lot of barriers with the 20 prevention on one side and mitigation on the other and I have 21 never thought about where it would stop.
f 22 If we have releases, we could give the iodine pills t
23 to mitigate those consequences and maybe that's where it stops.
24 CHAIRMAN ZECH:
Yes.
25 MR. SIESS:
Everybody defines it where they want it.
\\
]
j' 28 1
CHAIRMAN ZECH:- Mr. Kerr?
2 MR. KERR:
Two things I'd like to comment on.
First 3
is NUREG-1150, with which you are familiar and on which you are 4
getting reports.
This is said to be a very important part of
(
5 the severe accident program.
We have seen a first draft and t
6 have commented on it as have others.
If it is to be an
~_
7 important part of resolution of the issue, it seems to me it is 8
incumbent upon all of us to make certain that it is accurate 1
9 within the sources available and credible.
10 There has been some discussion of whether there 11 should be a peer review of the document in its filed form, and 12 while"at this point I am not speaking for the Committee, it may i
13 make a statement on this, I for one certainly believe that it 14 ought to be examined by a different objective group, call it 15 peer review or what.
I think the credibility of that document, 16 if it is cited, and I assume it will be, as one of those things 17 that contribute to the resolution of the issues.
It is very 18 important.
19 A second and I think unrelated comment I want to make 20 is that the existing regulations in the main come from a period 21 before WASH-1400, before we dealt with PRA's and used them very 22 much.
Ih is very difficult to go back and reconstruct those 23 regulations but in some cases it seems to me we need to look 24 carefully at that possibility.
I think particularly of f
15 containment.
9 w w
29 1
The containment criteria, design criteria that exists 2
for containment, with a few small exceptions, are based on our 3
pcstulated design basis accidents that came into existence in 4
the late 1960's and early 1970's, and before we took into 5
account really that core melts were at least credible.
6 We have a lot more information now and yet those regulations for design still exist.
This is not too important 7
8 for operating reactors. They are there.
Nobody is going to 9
rebuild those containments unless we find out some things that 10 we don't now know.
For new reactors, it does seem to me we 11 need to reach some sort of decision based not just on the 12 consideration of those design basis accidents that were used to l
i 13 formulate today's regulations, but to take into account in i
14 whatever way and I don't have a solution to the problem at this 15 point, but to take into account in whatever way is appropriate 16 the fact that we now know a lot more about the possibility of 17 severe accidents and what some of the consequences might be, j
l 1
18 Therefore, we might arrive at some slightly different 19 conclusions about the way in which one ought to design 20 containments.
21 CHAIRMAN ZECH:
All right.
We appreciate your l
l 22 comments.
23 MR. MICHELSON:
May I reinforce Dr. Kerr's comment on l
24 NUREG-1150.
The peer review at the time it was performed did 25 not have the opportunity to review in detail how the external l
l
}
30 1
events would be handled'because that is still ongoing work as I 2
understand it and it is going to be only for Surry and Oyster 3
and Peach Bottom.
At such time as the external event work has
~
4 been completed, I think it will be esnontial that the approach 5
in the work proceed in a good peer review.
That is not 6
presently in the package, at least as I understand it.
7 CHAIRMAN ZECH:
All right.
We appreciate that 8
comment, too.
Any other comments?
9 MR. WARD:
I would just like to add or endorse what 10 Dr. Kerr said about the need for establishing some new design 11 criteria for containments based on present knowledge.
Twenty
~
12 to twenty-five years ago the decision was made that although we 13 needed to have containments for severe accidents, we didn't 14 know enough about the nature of severe accidents to explicitly 15 design the containments for those.
We sort of finessed the 16 problem by designing them for kind of an artificial set of 17 circumstances and that has probably worked out pretty well we 18 think.
It worked great at TMI-2.
The present analyses say 19 many of these containments are pretty good.
To what extent 20 those conclusions are a little bit self serving, I'm sometimes 21 a little cynical about them.
22 We now know an awful lot more about severe accidents b
23 than we did 25 years ago.
I really think it is time to come to 24 grips with it and come up with a new, better set.of design 25 criteria.
I don't see either the agency or the industry really
7 l
31 1
working toward that.
Nobody is paying any attention to it.
2 MR. MICHELSON:
If it isn't done pretty soon, it 3
isn't going to be timely for ABWR and some of these other 4
advanced concepts that we are in the review process on already.
l 5
How do we get these new ideas which the severe accident' policy 6
said we would incorporate into future-plants?
How are they 7
going to get in if we don't see some real activity in that area
~
8 soon?
9 CHAIRMAN ZECH:
Why doesn't the ACRS give us a paper 10 in that regard?
11 MR. SIESS:
We are not smart enough.
)
~
12 MR. WARD:
That is one reason.
13 CHAIRMAN ZECH:
Now we have a little discussion.
j 14 MR. SIESS:
If by designing new design criteria, I I
15 don't think we have the information.
i 16 CHAIRMAN ZECH:
That's why we don't have a paper.
17 MR. SIESS:
We don't know what we are going to design 18 for direct containment heating, for steam explosion, for 19 hydrogen --
20 CHAIRMAN ZECH:
When you figure it out, maybe you can 21 give us a paper.
22 MR. SIESS:
What we have learned is what not to do.
23 We are not going to build any more low pressure capacity ice 24 condensers or low pressure capacity suppression systems, like 25 the Mark III or the ice condenser.
We don't know whether to
a l
32 1
design them for 60 psi or 75 or 100.
We have learned something 2
but it is what not to do.
We will work on it.
3 CHAIRMAN ZECH:
Obviously the ACRS doesn't have an 4
unanimous conclusion but please do work on it.
It is an 5
important issue.
We should try --
6 MR. SIESS:
I don't think we are 9 to 1 yet either.
7 CHAIRMAN ZECH:
Maybe you won't even be 9 to 1.
~'
8 Are there any other comments?
9 COMMISSIONER ROBERTS:
I would like to ask a question 10 unrelated to anything we have talked about.' As I understand 11 it, you didn't have the benefit of commenting on the policy 12 statem'ent on maintenance but there was a staff requirements 13 memo that I will read from that says "The staff should f
14 periodically brief the ACRS and seek their input during the 15 development of the notice of the proposed rulemaking."
16 Is that occurring?
17 MR. MICHELSON:
Yes.
The answer is yes but we 18 haven't briefed you yet because the staf f is still developing -
19 its paper.
20 COMMISSIONER ROBERTS:
Are you working with the 21 staff?
22 MR. MICHELSON:
Yes.
One member of the Committee 23 attended all three days of the workshop.
There is a staff 24 briefing for August.
There is a detailed subcommittee l
25 presentation scheduled for Wednesday, full committee in 1
33 1
September, and a letter from the Committee will be forthcoming 2
in September.
That is our present schedule, if nothing happens 3
in the meantime.
4 CHAIRMAN ZECH:
Thank you very much.
Other comments 5
from my fellow Commissioners?
6 (No response.)
~.
7 CHAIRMAN ZECH:
Let me thank you for a very important 8
presentation today on ISAP and IPEs, PRAs, and other very 9
important issues.
I appreciated the discussion on the severe 10 accidents.
Certainly we have put a lot of effort into that and 11 as has the staff recently, as hau the Committee, too.
~
12 I will look forward to hearing from the staff next 13 week.
i know the Commission looks forward to coming to some 14 closure on this IPE, ISAP issue soon.
I appreciate what the 15 ACRS has done in working with the staff on this issue.
I think 16 we have come a lot closer together than we were some time ago.
17 That is encouraging to me.
We do want to make the best i
18 decision we possibly can but we will make a decision.
We 19 appreciate very much the work of the ACRS in this and other 1
20 fields that you are involved in continually, f
21 Thank you very much for a fine briefing.
We 22 appreciate it.
23 We stand adjourned.
24 (whereupon, at 2:55 p.m.,
the briefing was 25 concluded.)
s CERTIFICATE OF TRANSCRIBER This is to certify that the attached events of a meeting of the U.S.
Nuclear Regulatory Commission entitled:
1 TITLE OF MEETING:
PERIODIC BRIEFING BY THE ADVISORY COMMITTEE; ON REACTOR. SAFEGUARDS PLACE OF MEETING:
Washington, D.C.
DATE OF MEETING: THURSDAY, JULY 16, 1988 i
i were transcir ad by me.
I further certify that said transcription is accurate and complete, to the best of my ability, and that the transcript is a true and accurate record of the foregoing events.
3 i
Ann Riley & Associates, Ltd.
i e
j PERIODIC. BRIEPING BY THE 2:00 P.M.,
July 14, 1988 i
ADVISORY COMMITTEE ON REACTOR i
j
, SAFEGUARDS (ACRS)
CARROLL SHEWMON WYLIE i
V V
SIESS WARD 7g j
l KERR I
MICHELSON i
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i PARLER I
CIIILK i
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COMMISSIONER i
COMMISSIONER COMMISSIONER CARR t
ROGERS CIIAIRMAN ROBERTS i
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2 Attached are copier of a Comission meeting transcript and related meeting i;
document (s). They are being forwarded for entry on the Daily Accession List and i
pla;ement in the Public Document Room.
No other distribution is requested or j
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