ML20207P772
| ML20207P772 | |
| Person / Time | |
|---|---|
| Issue date: | 01/08/1987 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| ACRS-T-1569, NUDOCS 8701200193 | |
| Download: ML20207P772 (179) | |
Text
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UN11ED STATES I
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NUCLEAR REGULATORY COMMISSION ORIGINA1 IN THE MATTER OF:
DOCKET NO:
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 321TH GENERAL MEETING O
LOCATION: WASHINGTON, D. C.
PAGES: 1 - 175 DATE:
THURSDAY, JANUARY 8, 1987
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OfficialReporters 444 North Capitol Street Washington, D.C. 20001 (202) 347-3700 0df 7
NADONWIDE COVERAGE
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PUBLIC NOTICE BY THE UNITED STATES NUCLEAR REGULATORY COMMISSIONERS' ADVISORY COMMITTEE ON REACTOR SAFEGUARDS THURSDAY, JANUARY 8, 1987 The contents of this stenographic transcript of the proceedings of the United States Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards (ACRS), as reported herein, is an uncorrected record of the discussions recorded at the meeting held on the above date.
No member of the ACRS Staff and no participant at
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this meeting accepts any responsibility for errors or inaccuracies of statement or data contained in this transcript.
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2 NUCLEAR REGULATORY COMMISSION 3
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
5 321TH GENERAL MEETING 6
Nuclear Regulatory Commission 7
Room 1046 1717 H Street, N.W.
8 Washington, D.
C.
9 Thursday, January 8, 1987 10 The 321thlGeneral Meeting convened at 8:40 a.m.
11 12 ACRS MEMBERS PRESENT:
]
13 DR. FORREST J. REMICK, Presiding..
14 MR. JESSE C. EBERSOLE MR. HAROLD ETHERINGTON 15 DR. MAX W. CARBON DR. CARSON MARK 16 MR. CARLYLE MICHELSON DR. DADE W. MOELLER 17 DR. DAVID OKRENT MR. GLENN A.
REED 18 DR. FORREST J.
REMICK DR. PAUL G. SHEWMON 19 DR. CHESTER P.
SIESS MR. CHARLES J. WYLIE 21 22 23 24 25 ACE-FEDERAL REPORTERS, INC.
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PROCEEDINGS 2
(8:40 a.m.)
3 DR. REMICK:
Our first item on.theJagenda this 4
morning is-the subject of General Electric advanced boiling 5
water reactors.
The subcommittee met yesterday.
Dave-6 Okrent is the chairman of that subcommittee.
7 Dave, you have two hours, until 10:45, for.that 8
presentation.
Do you want to take.it up?
9 DR. OKRENT:
Thank you, Mr. Chairman.
I 10 I guess a proposed schedule for today's 11 discussion is being handed out.
I offer brief comments in j
12 terms of it.. And it shows me as having 10 minutes; I intend 13 to use less.
14 This is what you would call, I guess, an 15 information session.
That is, we do not expect that the 16 committee would have the basis for writing a letter, even if 17 that were being requested at this meeting.
18 However, it is my opinion, and I think the 19 opinion of the subcommittee, a rather important piece, one 20 to which the full committee should devote considerable time 21 for each member to get himself sufficiently well-acquainted 22 with what he considers to be the important matters over the 23 next one or two months or three months, or whatever is the 24 schedule, before it's probably time for us to write a first O
25
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The first question that it appears will come 2
before the committee on which they are asked to offer an 3
opinion relates to something called the licensing basis 4
agreement.
5 And this is an effort, at least a first time 6
effort in these contexts, to try to define the matters that 7
will be subject to discussion, to review and so forth, and 8
so on.
9 And, as you know, in the program that EPRI has
, 10 been conducting with staff over many months now, they have 11 been trying to start with a long list of items and work l
12 down, saying these are not operable for one reason, and O( /
13 these are not, and in trying to get resolution for these j
14 others, and so forth.
15 Ilowever, the EPRI focus in large part was on l
16 things like generic issues of what I'll call the more usual l
17 kind, and I think did not come head on with severe accident 18 issues, and certainly di.d not come head on with some of the i
19 kinds of things that the committee currently has under i
l 20 consideration in its current draf t letter on possible 21 improvements in future light water reactors.
l 22 So these are things that the committee is going 23 i to have to think about.
There are other kinds of things l
i l
24 that are not less important, but in a different voin.
Just
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i 25 l detailed does the design have to be because they're talking i
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about certification here, not the full plan?
But it's:quite 2-an extended nuclear island.
3 So I think, in fact, this is' going to require a 4
. lot of effort by the committee.and a few meetings.
The way.
5 we've laid out the agenda today is to, first, have an 6
uninterrupted presentation by General Electric,'after which 7
we will'have some discussion by them; and then an 8
uninterrupted presentation by the NRC staff.
9 And these times you see are the total times, 10 including discussion.
So they would need half the time 11 shown.
And then we thought we would pick one topic that 12 illustrated one kind of problem rather than trying to go
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13 through a host of problems which we never got our arms 14 around.
15 We picked one that Remick happened to raise in 16 the subcommittee meeting that seemed to introduce 17 interesting questions, both technical and procedural, as it 18 were.
19 So, again, this is an introduction to this 20 matter.
The full committee will hear from the staff what 21 they think.
I hope what we'll hear what the fairly 22,
realistic schedule is for when they will have all the I
j 23 i aspects of a licensing basis agreement.
i i
24 )
Well, I don't want to use the word " resolve", but O
i 25 at least in some form that they feel one is ready to l
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proceed.
But that's not today.
They'll presumablyftell you-2 some of the kinds of dates that they still have to work on.
3 I don't know if.the subcommittee members want-to 4
add anything at this time.
We had a good-turnout.
I would 5
propose to go.right into the presentation and, again,.except 6
for points of clarificatin ---and I would prefer that you 7
keep those points of clarification -
not opinion -- during 8
the presentations.
Let's try to let them get through.
9 And we will have a discussion after each group.
10 Okay?
I think that will work out in this case more 11 efficiently.
And I don't always recommend that. procedure,.
12 but I think here it will work out better.
13 In that case, General' Electric is up first.
14 DR. REMICK:
I believe we have a representative 15 from DOE that will make an introduction.
Mr. McGoff.
Is 16 that it?
17 MR. MCGOFF Thank you, Mr. Chairman.
My name is 18 David McGoff, the acting Deputy Assistant Secretary for r-19 Reactor Deployment in the Department of Energy.
20 I appreciate the opportunity to make a remark or 21 two before we start deliberations this morning.
DOE is 22 l participating in and sponsoring the G.E. ALWR safety 1
23 '
analysis and certification program.
24 I We're doing this as part of our advanced light C:)
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'important prongs towards' getting advanced light water 2-reactors to the point.where they're capable of being 3
' considered toward rejuvenation of the nuclear option in the 4
early nineties.
l 5
Those three points that we see are important are, 6
first of all, the utility' setting and their requirements'for 7
an advanced plan based upon all their experience, good and 8
bad, with the current generation of light water reactors.
9 Second of all, the vendors coming forward with a i
10 quality' design that can meet the standards required and can 11 have the attributes required to go through a certification 12 process to be shown to protect the public health and safety, fO 13 and again to incorporate the lessons learned from current 14 operations and current experience.-
15 The G.E. design appears to us to have a number of' 16 highly attractive features.
It incorporates technology not-i j
17 current available in current light water reactors.
18 The G.E. design appears to us to have a number of
-l 19 highly attractive featuros.
It incorporates technology not i
20 currently aval14. le in current light water reactors.
i 21 It appears to us to have greater margins to both 22 prevent accidents and also to mitigate severe accidents.
23 We're very interested in the deliberations over 24 the next few years during the regulatory process to see if, i
C) l 25 indeed, this promise holds true.
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l' Again, I thank you for the opportunity of being 2
here.
We're looking forward to the deliberations.
We'd 3
like your feedback.
We're very attentive during this time.
4 And, thank you very much.
5 DR. MOELLER:
Excuse me.
I thought you said you 6
had a three-pronged program.
I heard two prongs.
7 MR. MCGOFF:
That's because I folded the 8
regulatory attributes into the other attributes.
9 DR. SHEWMON:
Let me ask about prongs in a 10 different direction.
In the Japanese project, at least, 11 there was a PWR -- Westinghouse-Mitsubishi, probably.
Is 12 there one in this country also?
Or is that coming through
<s-)
13 in this same program?
14 MR. MCGOFF:
Westinghouse is working with the 15 Japanese on an advanced PWR.
I believe that's before the 16 Commission now, looking towards a preliminary design 17 approval.
18 We're going to be assisting Westinghouse in that 19 activity on severe accident analyses.
Combustion f
20 Engineering also has its System 80 advanced reactor, a 21 modification of System 80, which you'll be hearing about in 22 :
the near future, also under T&V sponsorship.
l 23 l DR. SHEWMON:
I understand that, but I figured 24 l G.E. couldn't tell me too much about the PWR, so I'll ask
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you.
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'MR. EBERSOLE:
Is this just a philosophical 2
endorsement of this, or.are there material aspects that 3
you're-talking about?
4 MR. MCGOFF:
DOE'is funding on a cost-shared 5
basis the safety analysis and certification activities of 6
the G.E.
reactor.
7 MR. WARD:
A followup.
It's funding'to what 8
extent?
What's the funding level?
9 MR. MCGOFF:
Roughly, over a three-year period, I 10 believe the funding level is something on the order of $8 11 million in DOE funding.
i 12 DR. REMICK:
No further questions?
13 (No response.)
14 DR. REMICK:
We're ready for the second 15 G.E. presentation.
Thank you, Mr. McGoff.
16 MR. WILKINS:
Thank you, Dave.
17 Mr. Chairman, Members of the Committee, I'm Dan 4
18 Wilkins, General Manager of the Advanced Boiling Reactor 19 Program.
I very much welcomed the opportunity to be here 20 and speak to the full ACRS committee today on our advanced 21 BWR program.
22 i I am going to try in a very short overview 23 presentation to give you a summary of the ADWR program, and 24 try to leave a lot of time for discussion.
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25 l (Slide.)
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'Let me begin by reminding you of the objectives 2
of the program.
This program was started back in the late 3
seventies.
Its objective was to come up with an advanced 4
boiling water reactor which would have improved operability, 5
capacity factors, safety performance and reduced 6
occupational exposure, reduced rad wate and reduction in all 7
elements of plant cost.
8 I'll show you shortly how we think we've come out 9
on that.
10 (Slide. )
11 Our development approach was to pull together the worldwide BWR suppliers.
We assembled a team in San Jose of 12
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13 approximately 25 senior engineers from Acea in Sweden, 14
-Hitachi and Toshiba in Japan, General Electric, Salvo, 15 Italy, a number of architect-engineers and asked them to 16 pool their worldwide design technology experience and come 17 up with the best BWR that you could possibly como up with 18 from a total, worldwide perspective.
19 That was the basic concept of the ADWR, that 20 it was completed in 1979, for the past roughly five years, 21 the program has been focused in Japan under the sponsorship 22 I of Tokyo Electric Power Company and a consortium of Japanese i
23 utilities.
24 And the technical offort being carried out in
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partnership betwoon General Electric, Ilitachi and Toshiba.
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That development effort is now essentially 2
complete.
It has brought the design to a fairly advanced 3
state.
It has supported that design by a major test program 4
and overall, today, the effort is on the order of $250 5
million of investment in it.
And it's ready for lead plant 6
application.
7 And we expect to see the lead plants proceeding 8
in Japan in the near future, with a target of having it 9
operate in the mid-nineties.
10 (Slide.)
11 Just to summarize the key features, and I won't 12 go into those in any detail this morning because we did go V
13 through them yesterday at some length, and each of you has a 14 book that summarizes the key features of the ADWR.
15 And since most of you attended the subcommittee 16 meeting yesterday, I'm going to try to save some time by not 17 l going into these.
I 18 l But the basic features are shown here.
We 19 adopted the internal recirculation pumps from the European 20 ;
designs of Acea.
And the fine motion drive was an early 21 !
G.E. design that was later further developed by 22 Kraf twek-Union and we' re now in ef fect bringing it home.
23 Digital solid state control and multiplexing are 24 )
technologies that we're really applying for the first time (O
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advanced fuel that is being used in all of our BWRs 2
worldwide.
And the containment and reactor building is an 3
advanced design.
4 That is an evolution beyond our Mach III.
And 5
we've gone to an optimized, and I might say somewhat 6
simplified emergency core cooling system that has both 7
greater redundancy and greater simplicity.
8 (Slide. )
9 This chart summarizes the key characteristics of 10 the ABWR.
It's a large plant, 1,350 megawatts.
It's 11 engineered for construction in 48 months from first 12 concrete to turnover.
It's expected to have a high capacity 13 factor on the order of 86 percent, a 55-day refueling 14 outage.
We designed it for load following capability, for 15 50-100 percent of power range.
16 Our probabalistic risk assessments indicate a 17 coro damage probability of loss than 10 to the minus 6 per 18 year.
i 19 DR. S!!EWMON:
What did your own plants rate on 4
20 that, just so we can calibrate it?
21 MR. WILKINS I would say this is about a decade i
22 !
better.
They're generally in the 10 to the minus 5 region.
23 And our estimates of occupational exposure are under 100 24 man-rom por year.
O 25 !
Wo expect loss than 100 barrois of waste por i
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year.
2 DR. SHEWMON:
Again, would you compare that with 3
the BWR?
4 MR. WILKINS:
The average BWRs in the U.S.
today.
5 DR. SilEWMON:
Let's go to Susquehanna, or 6
something that's not the oldest plant around.
7 MR. WILKINS Let me give you two numbers.
The 8
fleet average is maybe in the vicinity of a thousand man-rem 9
per year.
The best plants in the world are now running 10 around 100.
Under 100, actually.
11 So this is really taking the best that has 12 already been accomplished and making sure we repeat it.
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13 Rad waste.
That represents on the order of a 14 factor of 5 reduction over what's currently being achieved.
15 DR. MOELLER:
What is a typical refueling outage 16 for existing plants?
The time compared to the 557 l
17 l MR. WILKINS:
Typical, I would say, is probably 18 more in the vicinity of 75 days.
So we think we have made 19 significant stridos forward with this design on virtually t
20 all fronts.
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(Slide.)
2 From a safety perspective, we have incorporated 3
into the design many features which we think give it a major 4
step forward over what we have done in the past.
5 I have listed some of the key ones here on the 6
left side of this chart.
7 The elimination of the recirculation piping is of 8
course a very key issue.
This has eliminated a major source 9
of radiation in the dry well.
It has eliminated the 10 existence of large pipes below the core in the vessel, and 11 it has made a loss of coolant accident by eliminating that 12 large break.
Akl 13 We have made the loss of coolant accident a much 14 more mild event.
Because of that we have been able to size i
15 the emergency core cooling system so that the core does not 16 uncover for any pipe break.
We never go through the 17 uncovery and reflood and heatup that is characteristic of 18 current designs.
19 We have gone to a diverse control rod drive, 20 which is scrammed hydraulically, inserted electrically, 21 which gives us a little diversity we haven't had before, and 22 at the same time we have eliminated the scram discharge 23 volume.
i 24 Three full divisions of decay heat removal and O
25 core cooling, both mechanically and electrically, and F
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physically separated.
2 We have gone to the full power and 3
self-diagnostic control and instrumentation, which is,a 4
major improvement in reliability.
5 Of course, we used all of the latest technology, 6
materials and water chemistry that we have for the BWR, and 7
we have used our latest fuel pellet clad interaction 8
resistance.
9 All of those add up to a great improvement in 10 safety.
At the same time we have optimized some features in 11 the safety area.
We plan to use the leak before break 12 criteria in terms of piping designs.
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13 Because of the better fuel performance that we 14 are now experiencing, we have done some down-sizing in the 15 areas of off-gas and standby gas treatment systems.
16 So that is a very quick overview in the safety 17 area.
18 (Slide.)
l 19 I mentioned that this design has been supported 20 by a very large test and development program.
I won't take 21 you through that, although in your book if you care to leaf 22 through you can see the basic content of the test and 23 development program that is laid out there.
24 l What we did is we adopted a philosophy that overy O
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experience or proven by test in this program.
So every 2
feature that we could not point to operating experience on 3
we conducted test programs to make sure.we didn't have any 4
surprises.
5 In all, there were on the order of 20 or 22 major 6
test programs, and the way we worked that out is we divided 7
it up equally between ourselves, Hitachi, and Toshiba.
We 8
did roughly a third of them, and then we shared rosults.
9 So we have leveraged our effort.
s 10 Yes, sir.
11 DR. SHEWMON:
One that you htave skiiiped as you 12, went through and talked about the containmentireactor 13 building, could you tell me what the SSE is for the base 14 plant?
15 MR. WILKINS:
We intend to meet the.3 G that is 16 in the EPRI requirements document.
17 DR. SHEWMON:
Okay.
18 MR. WYLIE:
This test is true of your solid state 19 instrumentation and control?
20 MR. WILKINS:
Yes.
21 (S lide. )
i 22 i Now, I mentioned that the development is l
23 !
essentially complete at this point.
The project is moving 24 ahead toward lead plant application in Japan, and we are now O
25 taking steps to bring the design home really to the U.S.
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'As Dave McGoff mentioned earlier, we are doing ry --
'$this as part of the three-part program, in which the 2
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3 b ilities through EPRI are establishing the requirements for
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4 the next generation plants. LWe are very much involved in 5
Ithat program.
6 The industry task is to bring forward the 7
des igns.
We have been very fortunate to have the support of 7
8 Che Department of Energy to support this regulatory review
-9 and eventual recertification program.
10 Those three packages -- the utility effort, the 11 design effort, and the certification effort -- are a very 12 integrated set.
('
13 (Slide.)
14 This chart summarizes the schedule for those 15 activities.
What I have shown in the green bars on the "e
16 chart is the schedule for the requirements effort under 17 EPRI's ALUR program.
And you can see the various schedules 18 for the various requirement modules to be created and go 19 through the review process.
(
20 The rod bars show our plans for the ABWR 21 certification effort.
I 22 Wo intend by the middle of this year to have in 23 place a licensing banis agreement which will provide the 24 framework for the follow-on preparation of the safety O
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carried out over the next roughly three years, with final 2
design approval targeted for 1990, and then we expect to go 3
on from there into a certification step which would be 4
completed in 1991.
5 The purpose of the licensing basis agreement is 6
to get up-front agreement on all of the requirements.
7 We have tried in this program to pull together 8
the worldwide technology into a single design.
We have 9
built on our GESSAR experience.
We have addressed every 10 unresolved safety issue and every one of the generic' safety 11 issues.
12 We have factored into the design all of the n)
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13 lessons from Three Mile Island, and we think that we are 14 bringing forward a design that meets all of the 15' requirements.
16 But in order to make sure, we have scheduled this 17 licensing basis agreement up front to make one last survey 18 of the landscape, and if there is anything we missed, we 19 want it brought out on the table up front so that we can 20 then proceed through the safety analysis report and the 21 licensing effort in a smooth manner.
22 That is really the fundamental purpose, in our 23 view, of that licensing basis agreement, is to make sure 24 that we have caught and brought together all of the 25 requirements.
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. Our focug; in that agreement is really to address 2
the ones that any of us think might be trouble spots 3
downstream.
If any of the participants.are concerned about 4
a possible misunderstanding on requirements, we wanted to 5
find that out up front and get it resolved before we proceed 6
on with the effort.
7 So that is the purpose there.
8 The end point of the program is a certified 9
design, which we would expect to be a certified 10 U.S.
standard plant which could be built by multiple 11 utilities on multiple sites without further review, other 12 than of course compliance review to make sure that it was in O
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13 fact built as represented.
14 But the idea is once that certification is in 15 place that design is an improved design for a 10-year 16 period, with an option for renewal, and it would not be 17
. subject to further review beyond that.
18 DR. OKRENT:
Is this a point of information?
19 MR. EBERSOLE:
It has to do with documentation.
20 MR. WYLIE:
Before he leaves that slide, I think 21 it would be a most appropriate time to talk about scope, for 22 which the certification is sought, particularly since it 23 shows Item 3 here under Task 2, turbine island, which is 24 confusing to me a little bit.
25 In other words, would you explain the scope of ACE-FEDERAL REPORTERS, INC.
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what certification is sought for?
2 MR. WILKINS:
We plan to bring for certification 3
a nuclear island design roughly at.the same scope as it was a
4 in GESSAR, which includes all of the safety significant 5
portions of the~ plant and pins down interfaces with balance 6
of plant.
7 MR. WYLIE:
What is confusing is the turbine 8
island and the SAR, and so forth.
9 MR. WILKINS:
The EPRI requirements program is 10 addressing the entire plant, including turbine island.
That 11 is what the green bar reflects there.
12 What we would do in that area is interface.
13 MR. WYLIE:
You would just write an interface 14 document, okay.
15 MR. EBERSOLE:
On the subject of the degree of 16 detail, can you give me an --
17 DR. OKRENT:
Can we come back to degree of detail 18 questions if it is a specific one, Jesse, because it is 19 broader?
20 (Slide.)
21 MR. WILKINS:
Let me just finish.
I have one 22 more chart.
23 (Slide. )
24 What we request from the ACRS is your working I
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table up front.
2 We, as I'have mentioned, have put a lot of work 3
into this design ~, a major investment.
We are not eager to 4
.make changes to it, but if, on the other hand,'you are 5
looking.at the design and looking at what is needed for the b
'6 future and you find things we have missed or things we.ought-
~
7 to have done, we want.to hear about them and consider them,.
8 and we want to do that up front.
9 That is really our immediate request, is your 10 assistance in helping us get the. requirements defined 7
i 11 quickly, and then of course we will~be looking for your j ~
support throughout the review on the schedule we have laid 12-j 13 out, which is roughly a three-year schedule..
if 14 That is my speech.
15 DR. OKRENT:
We have about 25 minutes now for i
{
16 questions.
I
.17 MR. EBERSOLE:
Let me ask you this'.
The old j
18 GESSAR II produced a licensing document, an FSAR of a i
~ 19 certain size, magnitude, degree of detail, et cetera.
I 20 How do you envision the expansion of this to 21 include the detail necessary to get this plant in place?
22 I can see a vast expansion of detail.
What do i
23 you see?
24 MR. WILKINS:
I would expect it would be roughly O
25 comparable to GESSAR.
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MR. EBERSOLE:
Now, you know the typical-FSAR has 2
got very little in it in the context of detail, far less 3
than I would anticipate in a standard plant.
4 You are telling me you don't see any finer 5
structure than you see in the current FSARs?
6 MR. WILKINS:
That is correct.
We intend to have 7
-- we have in' place the information that is consistent with 8
the AIF's policy position paper on standardization.
That 9
level of design information will be available for this 10 review, and that represents, I think, a fairly well thought 11 out position on what is needed to support a standardization 12-review.
k-)J r
13 That is what we intend to provide.
j 14 MR. EBERSOLE:
The problem has been in 15 interpretat on of the generalities in the FSAR.
)
16 Are you telling me there is going to be reference 17
. documents that you can be led into from the licensing 18 documents?
19 MR. WILKINS:
Certainly there is for any standard 20 plant a vast amount of low-tier information that is always l
l 21 available to support what is in the safety analysis 22 reports.
23 MR. EBERSOLE:
And that will be open for 24 inspection by the regulatory process?
)
l-25 MR. WILKINS:
Oh, yes.
l l
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'l DR. OKRENT:
Will it be part of the application, 2
the supporting material, a legal part of it?
3 MR. WILKINS:
Our safety analysis report would 4
follow -- what is it -- the Reg Guide 170 format,.and we-5 will provide the information that is specified there.
6 DR. OKRENT:
That is-a different. question'you are 7
answering.
I think Mr. Wylie and Mr.'Ebersole and'others 8
'are trying to ascertain the extent to which the design will 9
be specified, and if I understood you correctly,'it will not 10 be specified beyond what you said was ^ in the AIF 11 recommendation, which I assume is somewhat like what was in 12 GESSAR II.
-v 13
-Correct me if I am wrong.
i --
14 MR. WILKINS:
Rudy, can you help me there?
15 MR. VILLA:
Yes.
I think we are again dealing l
16 with the issue of what information is submitted in the safety analysis report versus what information actually 1,7.
l 18 exists in terms of defiaing the-design.
19 DR. OKRENT:
No.
What information is part of the
}
20 record in the certification process?
21 MR. VILLA:
The information that would be part of 22 the record would be that information supplied in the safety s
23 analysis report, which would be consistent with the information supplied as with GESSAR.
24 25 In addition to that, any information that the ACE-FEDERAL REPORTERS, INC.
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Staff requests for their review.
s 2
MR.-EBERSOLE:
Would the -- I will call it an 3
PSAR -- would it be an index to this other information and 4
there would be open access if the Staff desires to go in and 5
penetrate this?
6 I am talking about detail.
7 MR. VILLA:
Yes.
8 MR. EBERSOLE:
So it would serve as an index or a 9
table of contents as to where all the massive documentation 10 is?
11 MR. VILLA:
Yes.
12 MR. EBERSOLE:
That really defines the design b)
N/
13 because, as you well know, the FSAR is a very sketchy 14 thing if people want to look at real plant design.
15 MR. VILLA:
Sure.
There is not more than about 16 two or three hundred documents in an FSAR.
17 MR. WYLIE:
Maybe to clear this up a little bit, 18 what I think I heard you say was that you would supply or 19 have available for NRC review and supply with the 20 application what the Staff has identified in the AIF report 21 dated November 1986, Appendix B, which details design 22 information requirements.
23 Is that what you said?
24 MR. WILKINS:
Yes.
25 MR. MICHELSON:
Could I follow up on that ACE-FEDERAL REPORTERS, INC.
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question?
2 In your opinion, at least, what do you think is 3
being certi'fied when you receive your certification?
What 4
documents are being certified?
5 These are the documents now that are frozen,.so 6
=to speak.
1 7
MR. VILLA:
Right.
8 MR. MICHELSON:
What set of documents do you
-9 think are frozen at that point?
10 MR. VILLA:
Design description.
11 MR. MICHELSON:
First of all, the FSAR or the 12 equivalent is frozen clearly.
Beyond that, what are you 13 committing to freeze?
14 MR. VILLA:
Pretty much a level all the way down 15 to procurement type documents.
16 MR. MICHELSON:
Are those identified somewhere as 17 a listing, for tidiness at least, so we know what' documents 18 have now been frozen in design?
19 MR. VILLA:
Currently, they are not in terms of 20 the FSAR.
They are not included.
Of course, that was an 21 issue that we discussed at length at GESSAR, and I think we 22 have to resolve that, and we haven't resolved it as yet.
23 MR. MICHELSON:
That didn't seem to be treated in 24 the licensing basis document.
I think it should be before O
25 the document is approved as to what is being certified and 1
I l
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how will it b'e identified.
2 Thank you, Mr.. Chairman.
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\\j DAVbur 1-DR. SHEWMON:
When we discussed -- I guess GESSAR 2
was named.for the plant we wrote a letter on last' year?
3 DR. OKRENT:
GESSAR II.
4 DR. SHEWMON:
When that came through, one of the 5
systems that was unspecified had to do with how one could 6
get water into the well in the case of a severe accident, I 7
think.
8 DR. REMICK:
UPPS, wasn't it?
9 DR. SHEWMON:
There was some acronym like that.
10 One of the problems the committee had, or some members had, 11 was they said, yes, this will do wonderful; the thing is we 12 don' t know exactly what it is yet because we haven't been 13 forced or called upon to spell it out.
14 Is it any better spelled out in this plant?
15 MR. WILKINS:
Yes.
The system you are referring 16 to, the UPPS system, was an add-on system that was put in 17 from the GESSAR design relatively late in the design 18 process.
19 In this plant you will see an integrated and 20 optimized set of ECCS and decay heat removal systems which 21,
have been engineered as a package, which we believe provides 22 an even greater level of capability.
23 DR. SHEWMON:
Where will I see that if I wanted 24 l to look sometime?
(~T
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l MR. WILKINS:
First, there is a brochure in the 25 l ACE-FEDERAL REPORTERS, INC.
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1 back of your handout there that gives you a first
-2 description of it.
But the details would come in through 33 the safety analysis report, which we will be submitting 4
later in the year.
5 DR. SHEWMON:
And you feel that is now specified 6
adequately or at the same level as the rest of the plant?
7 MR. WILKINS:
Yes.
We don' t have a system by-8 that name in the ABWR.
9 DR. OKRENT:
There is not a UPPS, as it turns 10 out, in the ABWR.
11 MR. WILKINS:
You will find a number of 12 terminology changes as we have integrated and optimized the O4 13 design.
14 DR. SHEWMON:
Let me stay with that.
15 If I wanted to find that, then, what hea61ng 16 would I look under?
17 MR. WILKINS:
It would be under the combined 18 emergency core cooling and decay heat removal systems.
19 DR. SHEWMON:
Thank you.
20 MR. EBERSOLE:
The plant, too, is a suppression 21 pool design which rejects its heat through a closed system, 22 l a pool, and as you well know, one of the problems of this 23 has been cooling that suppression pool.
You require the 24 l persistence or recovery of electric' power.
O 25 Now, the boiler has the unique privilege of ACE-FEDERAL REPORTERS, INC.
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doing a very simple two-cycle cooling process.
You have 2
sacrificed that on the grounds that you have added a third 3
train.
That is all I have seen you have done.
4 I don't think the addition of the third train 5
. compensates for the loss of that unique, simple, extremely 6
simple -- even Chairman Zech says he must have simplicity --
7 ultimate final cooling process, and I personally regard the 8
absence of UPPS as a serious fault i'n this design because I 9
am not talking about post-accident.
I am talking about 11 0 pre-core damage utilization of that sort of system.
11 It is not costly.
It is not complex.
It is 12 ultimately simple and will operate in the most simple sort s
13 of way.
x 14 You have thrown it to the winds, and I don't like 15 it.
16 MR. WILKINS:
That is an item we can go into 17 during the course of the review.
We can give you the logic 18 that we went through in arriving at what we did, and that is-19 a fair item for discussion.
20 DR. OKRENT:
Mr. Moeller.
21 DR. MOELLER:
Go ahead and follow up.
I am 22 j changing the subject.
I 23 l MR. WYLIE:
Okay.
The plan is part of this I
24 l ability to prepare the emergency operating procedure?
(*)
25 MR. WILKINS:
What is the question?
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MR. WYLIE:
Do you plan to have those available?
2 MR. WILKINS:
We would have, I guess, the 3
equivalent of our emergency procedure guidelines, the 4
requirements for the emergency procedure.
We wouldn't 5
expect to actually write the plant procedures as part of 6
this effort.
7 MR. EBERSOLE:
What about the normal operating 8
procedures?
9 MR. WILKINS:
Rudy, where does the AIF --
10 DR. MOELLER:
Generally, we would write the 11 normal operating procedures.
12 MR. EBERSOLE:
But not the emergencies?
13 MR. WILKINS:
Maybe we have got a terminology 14 problem.
15 DR. MOELLER:
Yes.
We probably do have a 16 terminology problem.
17 Which-procedures are you referring to 18 specifically?
19 MR. EBERSOLE:
When I get in trouble, I want to 20 know how to get out.
I want to know the track of the 21 operator as he follows the course of some transient or 22 cascade, and I don't know how you have a design until you 23 know how he does that.
l 24 DR. MOELLER:
In those kind of procedures we rm i
I
's ) '
l 25 would be writing the guidelines.
l l
l l
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MR. EBERSOLE:
I realize the guidelines, sure.
2:
DR. OKRENT:
Would they go,beyond the core damage 3'
phase into what sometimes is called the accident management 4
phase?
5 DR. MOELLER:
At this point I don' t believe we --
6 have an answer to that question because we have at this 7
point not done it, and we haven't defined necessary actions 8
beyond the severe' accident phase.
9 You remember our discussion.
10 MR. WILKINS:
Beyond severe accident?
The BWR 11 emergency procedure guidelines for existing plants go well 12 into the degraded situations, well beyond the design basis, r')
k/
13 and provide guidance to the operators.
14 MR. EBERSOLE:
One of the most nervous of these 4
15 is the post-ATWS procedures.
16 Would you anticipate not having to do that here, 17 or would you do it?
18 MR. WILKINS:
This design has major improvements 19 in the ATWS area.
20 MR. EBERSOLE:
I know, I agree with them.
n 21 MR. WILKINS:
Whether that would impact it --
22,
well, it would certainly impact what the procedures say in 23 the ATWS area.
Whether it would take out that whole section 24 of the procedures or not, we haven't really dealt with.
(
25 DR. OKRENT:
I think there may be a difference ACE-FEDERAL REPORTERS, INC.
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in what you mean by severe accident and I do.
2 I am not aware that there are emergency operating 3
procedures for BWRs in which it was accepted that severe 4
core damage or core melt has occurred, and-things are now 5
looked at under a variety of what might be available or not, 6
what might happen or not, and procedures developed.
7 You can't certainly use the symptoms you used in 8
the first set of symptom operating procedures because those 9
didn't work presumably.
For one reason or another, you got 10 beyond that stage.
11 I don't think you have got those.
Correct me if 12 I am wrong.
p)
(-
13 MR. WILKINS:
Greg, you may want to comment on 14 this.
15 I would say our emergency procedure guidelines go 16 into some areas.
17 MR. SAWYER:
The procedures that are on the 18 record go down to the point of severe core damage.
As I 19 say, they take on the issue of doing everything possible to 20 avoid core damage.
21 l The BWR Owners Group is presently wrestling with 22 whether or not to take on the issue of what to do beyond 23 that.
l 24 DR. OKRENT:
I agree with what you said as far as O
25 the status, and I was asking whether for this plant you ACE-FEDERAL REPORTERS, INC.
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currently envisage going the next step, which has in. fact 2
been pursued in some countries, and within the NRC there 3
have been considerable expressions of interest.
4 MR. SAWYER:
We hadn't planned to do it.
5 MR. MICHELSON:
Just for a point of clarification 6
on this question, at least for the case of Susquehanna there 7
is a procedure for containment control under severe 8
accident.
It calls for venting at 53 pounds in case all 9
else fails.
10 So at least one utility that I have found so far 11 does search into how to handle beyond the design basis j
12 conditions.
It was written back-in 1985, as a matter of 13 fact, in July of '85.
14 DR. OKRENT:
It is unfortunate the procedure 15 wasn't brought into the ACRS for review because we have 16 asked to review that.
17 MR. MICHELSON:
This is the only one I have found 18 so far.
Perhaps other exist as you start scratching around 19 in the industry.
But some people are at least thinking 20 about it.
21 Now, this isn't much of a procedure, to be 22 perfectly frank, but at least it addresses the issue, and 23 perhaps others are as well.
24 DR. MOELLER:
In your printed literature, it said 25 that the collective dose goal was something like 49, or the ACE-FEDERAL REPORTERS, INC.
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-estimate was 49 person-rem a year.
2 In the slide that you showed us this morning on 3
performance characteristics, it says occupational exposure 4
is less than 100 millirem a year.
5 MR. SAWYER:
That was a typo.
6 DR. MOELLER:
Do you mean less than 100 man-rem?
7 MR. SAWYER:
Man-rem.
That is a typo on that 8
chart.
9 DR. MOELLER:
You have also said in the written 10 material that some 60 percent of the reduction would be 11 accomplished'through moving one set of pipes.
12 Could you show me that a little more in detail or
.p
\\_/
13 tell me a little more about it?
14 I thought it was quite significant that 60 15 percent of the reduction could be accomplished by one basic 16 change.
17 (Slide.)
18 MR. WILKINS:
The ABWR has internal recirculation 19 pumps at the bottom of the vessel.
20 DR. SHEWMON:
Does this show -- that is in your 21 l handout.
It shows, I suspect, the pipes you are talking i
22 about.
That is just before one of the pretty colored 23 pictures.
24 MR. WILKINS:
I am talking about the elimination O
25 of the recirculation piping in the dry well, which has ACE-FEDERAL REPORTERS, INC.
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always been the largest radiation source and source of 2
occupational exposure.
3
' DR. MOELLER:
So with the internal pumps you have 4
been able to remove these pipes?
5 MR. WILKINS:
Yes.
6 MR. SAWYER:
May I clarify something?
7 I think there was a misunderstanding on the 8
extent of the emergency operating procedures.
There is a 9
Revision 4, which is under negotiation right now between the 10 BWR Owners Group and the Staff.
11 In this revision, items such as containment 12 integrity are on the table and are being discussed.
We k -
13 intend to be consistent with those.
We are going to go at 14 least as far as those procedures go.
15 DR. REMICK:
We have spent 45 minutes so far on 16 the 40-minute part'of the agenda.
I don't know if.you want 17 to shorten the other section.
18 DR. OKRENT:
Well, if the committee has more 19 questions of GE at this time, according to the agenda we 20 have a few more minutes.
21 ;
DR. REMICK:
I don't believe so if I am reading 22 i it correctly, but that is up to you.
23 DR. OKRENT:
How do you read it?
24 l DR. REMICK:
Those are minutes, including 25 questions that you have, and we are down still on new l
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features of the ABWR.
2 DR. OKRENT:
No, we are on GE views on the 3
licensing basis agreement.
4 DR. REMICK:
Oh, I am sorry.
I apologize.
5 DR. OKRENT:
In fact, I will pose a question to 6
GE in that area.
7 What do you view now as the most sticky issues 8
concerning the possible adop' ion of a licensing basis 9
agreement?
10 MR. WILKINS:
I would say two areas.
I think on 11 the technical front the severe accident area is probably the 12 most important one to reach an up-front understanding on, q(/
13 and then there are many areas which I think are much more 14 routine to deal with that need to be dealt with and have to 15 do with laying out the whole process for arriving at a 16 certified design.
17 That gets into the areas, some of which we talked 18 about this morning -- the level of information and what is i
19 actually being certified and what is the process for going i
20 l through all that.
21 !
DR. OKRENT:
Let me, if I may, add a personal 22 !
thought to that for the benefit, or not, of the committee 23 members.
24 There is no doubt that there are a host of
(~)
25 specific kinds of questions that are still being asked on ACE-FEDERAL REPORTERS, INC.
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existing plants.
2 Carl was interested in knowing -- not only Carl, 3
but Carl was interested in knowing can ventilation' dampers 4
malfunction in a way to let the hot air get from a fire to a 5
region where you have solid state control equipment that 6
will throw your plant into a very awkward state, and so 7
forth.
8 There is a wide range of these.
9 Secondly, there is the question of just what role 10 the PRA is going to play.
There is a requirement that there 11 be a PRA.
We had the experience in GESSAR of this partial 12 PRA.
There is still some kind of a PRA.
' x/
- 1. 3 How do you deal with that particular part.of the 14 plant, but also how do you judge its accuracy?
15 There may be an issue.
You are trying to say 16 that this plant, it is going to meet the Commission's safety 17 goals and some of these performance kind of high level 18 goals, like the 10 to the minus 6th thing.
l-19 Whose numbers are used?
What is the role of 20 uncertainties?
What do you do?
21 Maybe some responsible people say we really can't 22 give you a distribution.
It is nothing more than a wild 23 guess, and other questions of this sort.
24 So there are a range of different kinds of O
25 questions, some of which are quite specific, like this ACE-FEDERAL REPORTERS, INC.
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damper question, and somo kind of environmental 2
qualification questions.
3 There may be some questions that relate to the 4
adequacy.of some of the equipment in here that is different 5
from at least what we have operating experience in in the 6
U.S.
7 They have the internal pumps, with which there is 8
some experience abroad, but we don't know till in fact we 9
have a plant, whether they are identical and running under 10 identical conditions, that we are okay or there is something 11 funny here.
12 Maybe there is another kind of thing in the BWRs 13 that have recirculation piping while it was still being 14 postulated that there was a large break.
At least during I
15 the review of Newbold Island, GE argued that even if a 16 vessel failure occurred but it was less than this largest 17 break, they wouldn't have such severe damage to core 18 internals that there would be a problem.
There was enough i
19 core spray no matter where it occurred.
So they weren't 20 automatically in a problem.
21,
They now have eliminated any liquid breaks except 22 for small piping.
The main break is a steam line.
There 23 just are no more recirculation pipes.
24 So there is a family of things which are
)
25 different.
Some of them may be trivial to consider.
l l
ACE-FEDERAL REPORTERS, INC.
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We mentioned the question of what does one do 2
with regard to severe core damage.
There is the question, 3
of course, of sabotage.
They have not done anything beyond 4
what is required by the current Staff approach.
5 And then there is one related legal kind of 6
issue, and the Staff hopefully will tell us a little bit 7
about this.
8 If there are some things where we think.we just 9
can't tell from the current information -- that solid state 10 system really has sufficiently redundant H factors, cooling, 11 or they know enough about the possible effects of steam line 12 or they have sufficient backup for a range of losses of AC
(~)
(_)
13 power or whatever -- until you get into the nuts and bolts 14 of the actual design, which we are not going to do in this j;
15 first few months -- there isn't enough information for a 16 committee position -- but things may evolve in some of these 17 areas where the committee thinks a certified design like 18 this, which one hopes might be the basis for a real family 19 of reactors, these things should be done, modified, and so 20 forth.
21 22 l
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25 ACE-FEDERAL REPORTERS, INC.
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DAV/bc 1
At least in the discussions that were held over
-2 the subcommittee meeting yesterday, it was unclear to me how 3
things which are not spelled out in the licensing basis 4
agreement are picked up during this three to four-year 5
review.
6 Now, the staff may or may not tell us how these 7
are picked up.
That's one of the things you should watch 8
for.
9 There is some question as to is it backfitting.
10 Is it something that wasn't specifically called out in the 11 licensing basis agreement?
12 They don't call it backfitting, but they've got a
("
( )s 13 set of screening criteria.
14 DR. SHEWMON:
Who is "they" here?
15 DR. OKRENT:
The staff worked out, I think, 16 through apparently G.E.,
as I understand it.
So that's 17 something you want to look at in the next presentation while 18 you're thinking about what does the licensing basis 19 agreement mean.
(
20 This, I think, is the first time -- correct me if 21 l I'm wrong -- that this is being tried.
And so we have to 22 think about it whether, on the one hand, provides as much 23 stability as is practical, but on the other hand, provides j
24 necessary flexibility without what I will call the possibly rr l
25 severe impediments of backfitting; particularly the way we 1
1 ACE-FEDERAL REPORTERS, INC.
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(_/
DAV/bc-I heard it described yesterday, for example.
A rule of thumb-2 is that if something doesn't reduce the core melt-frequency 3
by a factor of 3, it's probably not something to pursue.
4 That's a pretty big effect.
Anyway, so I'm just 5
trying to give the committee some of the more complex things 6
that we're going to have to think about over the next few 7
months, that as we hear the staff, ask them what questions 8
you want.
9 DR. SHEWMON:
I have a couple of nuts and bolts 10 if we have the time.
11 DR. OKRENT:
We have time for a couple of nuts 12 and bolts.
Dr. Shewmon?
q
- k. l 13 DR. SHEWMON:
Do you want to respond to that?
14 MR. WILKINS:
Let me make a statement in response 15 to what Dave has said.
We are not trying through this 16 licensing basis agreement to have it substitute or preempt 17 the review process which we expect to go through over the 18 next few years.
And there will be literally hundreds, maybe 19 even thousands of issues that will come up in the course of i
20 l that three-year review, which we have the obligation to 21 bring our case forward and convince the regulatory community 22 ;
that what we've done is sound.
23 What we're looking for in the licensing basis 4
24 agreement is the very fundamental issues.
We want to be I) l 25 '
sure that we don't have any big philosophical disconnects ACE-FEDERAL REPORTERS, INC.
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'l on fundamental issues up front.
2 For example, if the concensus decision is that 3
the U.S.
should move to filter vented containments on light 4
water reactors, you know, we don't want to find that out 5
three years from now.
6 If the concensus is that future plants should be 7
designed to N minus 2 logic, we don't want to find that out 8
three years from now.
9 If the concensus is that only four division-ECCS 10 systems are acceptable, that's the kind of thing we don't 11 want to be surprised on.
12 As far as convincing you that within an agreed n-)
13 upon set of fundamentals, we've implemented them correctly, 14 that's what the three-year review process is for.
And we 15 don't intend to try to preempt that through the licensing 16 basis agreement.
17 Now let me say at the same time, as far as the 18 legal status of this agreement is concerned, we look at this l
19 agreement as a memorandum of understanding going into this l
20 program by the management of the various participants 21 involved.
l l
22 l Obviously, if new information comes up, there may 23 be a need to change the thing downstream.
But, basically, 24 we look at it as a going in, understanding, which, barring l
25 !
significant new information, we expect to be honored I
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throughout the program.
2 That doesn' t mean it's a legal document or a 3
backfit issue or those kind of things.
But that's the way 4
we.look at it.
We don't want surprises downstream on 5
fundamental issues in this program.
6 DR. SHEWMON:
Some nuts and bolts.
Will hydrogen 7
water treatment be a part of the plant design or just an 8
option at the discretion of somebody?
9 MR. WILKINS:
We plan to include it in the 10 design.
11 DR. SHEWMON:
Okay.
That's it then.
Thanks.
12 DR. MOELLER:
And your inclusion of it includes O).
(_
13 evaluation of the associated exposures, the increase that 14 might accompany that?
15 MR. WILKINS:
Yes.
16 MR. MICHELSON:
I'd like to comment on your 17 remarks on the licensing basis agreement.
I appreciate your 18 remarks.
I think that that is the right tone.
19 However, that doesn't seem to be the tone that 20 comes across when you read the licensing basis agreement.
21 It's a much more legalistic document.
The precise numbers.
22 l Then you say we will do this, we won't do that if 23 something comes in after a certain date.
I 24 '
MR. CARUSO:
As one who wrote it, I apologize for 25 its tone.
I just came off a project that was very involved ACE-FEDERAL REPORTERS, INC.
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1 in some legalisms.
s 2
(Laughter.)
4 3
MR. MICHELSON:
I think it's probably all right 4
to leave it that way, but to put in a preamble to the 5
document that really sets the stage, the intent of the 6
document.
And then let it sound legalistic thereafter, h
7 recognizing that the intent --
8 DR. SHEWMON:
Because there are lawyers in this 9
world.
10 MR. MICHELSON:
It came across as a very 11 legalistic document.
12 MR. CARUSO:
I think, if you read the abstract, I
,m
\\J 13 think the abstract really conveys that.
14 MR. MICHELSON:
In a way, it does.
But I like 15 his thoughts even better.
If somehow you get into that 16 feeling, you sort of realize this is kind of an 17 understanding but, certainly, as the situation evolves and 18 changes, we may have to do things differently.
19 MR. CARUSO:
It's just a draft document right 20 now.
21 !
MR. HERNAN:
I would point also, Carl, to the I
2 2 l-abstract does clearly say in terms of issues relating to the 23 ;
safety goal policy on severe accidents, in this document, 24 they are intentionally very fuzzy.
25 MR. MICHELSON:
Then, later on, the document is 1
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very clear,'you know.
It says, you know,. generic issues 2
after July 1st of last year won't be considered if they are 3
pushed and they are going _into'backfits, and things like 4
that, which is I think blowing the whole-idea.
5 MR. HERNAN:
The other thing, too, the committee 6
cannot disconnect what's going on here with the EPRI program 7
because the two are very much married.
The two are going on 8
simultaneously.
9 DR. OKRENT:
We're getting into the NRC staff 10 presentation, so why don't we have them give it.
11 (Slide.)
12 MR. CARUSO:
Good morning.
My name is Ralph 13 Caruso, the senior project manager of the ABWR project, in 14 the Division of Boiling Water Reactors.
15 I'm here this morning to talk about the staff 16 review plan and mostly the licensing basis agreement for the 17 ABWR.
18 (Slide.)
19 As just a highlight, the ABWR represents a number 20 of interesting licensing concepts that have not been seen 21 before in other plants.
The fact that it is a new 22 standardized BWR design, the use of the licensing basis 1
23 l agreement for the first time, the design certification and 24 l the use of the EPRI light water reactor requirements 25 document.
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In addition, because of the coordination between 2
G.E.
and Japan on the design, we anticipate that there will 3
be a coordination on the review effort between the~ United 4
States and the Japanese regulatory agencies.
5 That effort hasn't been started yet, but we 6
understand that the Japanese are very interested in 7
coordinating their review, and so on.
8 We will be discussing those matters with them in 9
the spring.
10 (Slide.)
11 The three most significant licensing concepts are 12 the international technical cooperation with the Japanese,
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13 the EPRI requirements document and the interface between the 14 ABWR and the EPRI program, and the licensing' basis 15 agreement.
16 As-Dan said, the idea of the licensing basis i
17 agreement is to define some issues before the technical 18 review begins, to provide a process for incorporating future 19 changes and to provide 4t"e procedures for certain technical 20 reviews.
21 Now I'd like to expand upon this a little bit.
22 This is a slide I used yesterday.
23 (Slide.)
AndIthinkalittlebilh5'kY8rsummaryofthe 24 O
'/
25 LBA and how the staff used the LBA.
We view the LBA as an ACE-FEDERAL REPORTERS, INC.
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agreement concerning the ground. rules and procedural 2
arrangements for-the ABWR review.
~3 We.think it will describe the_ scenario for the 4
review.- And, where possible, and when they are available, 5
it will provide the technical design bases for issues ~that 6.
have been troublesome in the past.
7 It's important that: you note that it 1says "Where 8
possible and when the technical design bases are 9
available".
_10 Then, in those cases where we have had problems 4
11 in the past, we.will include those issues in the LBA.
There I
12 will be some issues where we don't have those technical p/-
13 bases.
ss 14 Where those technical bases are not available, 15 then we want to establish a procedure in the LBA for 16 evaluating new issues as they arise.
17 During the review, I should note that the LBA is 18 not required by any regulation.
And as a matter of fact, we 19 don't have any regulatory basis for either its format or its 20 content.
It's not legally binding.
l 21 As Dan said, we think of it as a reasoned i
22 expression of intent by the staff and by the applicant, by 4
23 the parties involved.
A memorandum of understanding.
j '
24 There was some confusion yesterday about
_O L
25 backfitting and how backfitting applied.
We do not consider t
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'that-the backfit' regulations would apply to the ABWR until 2 ~
the final' design application.has been approved, the. final i
3 design approval has been issued.
4 Until then,.we intend to use the procedure in 5
Section 8.2 of the.LBA.
That'is the procedure that we'll be 6
.using for issues whose technical bases are not currently 7
available, but which are arrived at later.
8 This procedure in Section 8,.2 of the LBA-is 9
derived from the procedure that is being used by the EPRI' 10 program for new issues which arise during the review of the 11 EPRI program.
t 12-DR. OKRENT:
Are you going to show us that 13 procedure?
[
14 MR. CARUSO:
I wasn't going to put it up on the
~
15 board.
16 DR. OKRENT:
I thought I'd asked that that was 17 one that you would have.
~
18 MR. CARUSO:
I'm sorry.
I didn't realize that j'
19 you wanted a slide.
It is in the document that you have.
20 And I'll answer any questions on that, specifically.
21 DR. OKRENT:
Just let it go.
It's unfortunate 22 because --
23 DR. SHEWMON:
He said it's in the document we 24 have.
Is it in the notebook or what document?
25 MR. CARUSO:
There's a document that you have ACE-FEDERAL REPORTERS, INC.
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8 of'that document.
3 DR. SHEWMON: 'That's a separate handout?
4 DR. OKRENT:
Yes.
Not too easy to put your hands 5
on.
6 The page number is?
7 MR. CARUSO:
The version-you have doesn't have a 8
page number, but it's Section 8.
9 DR. OKRENT:
The point of interest is, while he 10 says there are no backfitting requirements, which is 11 certainly the legal position, since there is not an FDA, 12 there are proposed screening requirements which are 13 nontrivial.
14 MR. CARUSO:
In coming up with this procedure, in 15 defining this procedure, the staff was really led by the
+
16 fact that for-previous reviews of custom plants, of I
17 standardized plants, new issues arise and they're dealt with l
18 on an entirely ad hoc basis with regard to applying them to 19 the design.
20 There is no reasoned criteria or structure or 21 process for determining whether those issues should be 22 applied to a particular plant.
And the options that we 23 considered here were, one, to allow that situation to
't 24 continue essenti~ ally on an ad hoc basis for each item; or
('
25 try to define a procedure.
I ACE-FEDERAL REPORTERS, INC.
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l 2
procedure.
One of tb? reasons we want to talk to the ACRS 3
is to ask for your comments on that procedure, whether you 4
think it's a good procedure, a poor procedure, whether there 5-shouldn't be a procedure at all.
6 MR. EBERSOLE:
On this matter, I'd like to 7
comment on just the suppression bypass aspect as one of 8
100 or may 1,000 other matters.
The present design has 9
rather poor suppression bypass design.
10 They. commented yesterday that they anticipate 11 using jackheaded double role pipes like the Germans do, or 12 else getting rid of the suppression bypass piping system.
)
13 I wanted to point out that it's very important 14 that this be decided in the beginning because you'll never 15 find yourself able to do those things after you get into the 16 backfit mode, as we can' t put them, for instance, in Mach 17 II's.
18 MR. CARUSO:
The backfit rule does not apply to 19 this plant until the FDA has issued.
20 l MR. EBERSOLE:
I'm just saying you'd better not 21 l be caught with matters like this hanging over in the backfit l
22 l phase because the backfit process ryecludes conservatisms of i
23 that character.
24 MR. CARUSO:
Maybe that is an issue that O
25 >
G.E. will have to consider right now and say to themselves:
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Is this an issue we want to have to find up front?
2 That was, as Dan said, those sorts of major.
3L issues are the things we should be thinking about'now for 4
possible inclusion.
If those are a problem, we'll sit down 5
and we'll talk about it.
We'll try to include it.
6 LMR. EBERSOLE:
I can' t help but admire the change 7
in policy by G.E.
to do such things as this.
It's not
[
8 compatible, for instance, with the present GESSAR-2 designs 9
where we have single pipes.
And here we're going to do 10 something about that, whereas, in GESSAR-2, we cannot.
MR. CARUSO:
Well, we're not here to talk about 11,
12 GESSAR-2.
13 DR. REMICK:
Before you proceed, you said twice 14 that the backfit applies to the FDA.
But the draft 15 licensing basis agreement does not say that.
It says after 16 design certification.
17 Now, it's a small point but I just point out to 18 you what you're saying is not consistent with what the 19 document says.
20 MR. CARUSO:
Thank you.
I'll have to check 21 that.
As I say, it's a draft document.
It may be 22 inconsistent right now.
23 MR. EBERSOLE:
Correction.
I meant Mach II, not 24 i GESSAR-2.
'~
~
25 MR. CARUSO:
The draft LBA currently has a number ACE-FEDERAL REPORTERS, INC.
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of technical issues in-it.-
It has a blank spot for-the 2
-probabalistic risk assessment and the severe accident policy 3
statement.
4 Right now...
5 (Slide.)
6'
...the staff is in the process of preparing a
~
7 NUREG documer.t on the severe accident policy statement.
8 That is scheduled to be issued this spring.
The document 9
will also include some containment performance criteria this 10 spring.
4 11 As I understand it, the ACRS will be briefed in 12 late February, or the staff is looking to brief the ACRS in 13 late February on these documents before they're issued for 14 public comment.
15 Public comments will be incorporated into a 16 future reg guide which will be issued sometime-in 1988.
The 17 containment performance NUREG, I understand, may eventually 18 result in a rulemaking on containment performance criteria.
19 Until these reg guide and rulemakings are issued, 20 the staff will use the draft versions of the severe accident 21 policy statement reg and containment performance criteria.
22 t
23 t
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24 l (1) i 25 ACE-FEDERAL REPORTERS, INC.
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-1 Because'they will be available in the spring, we 2
think we will' be able to incorporate them into the LBA 3
= before Lthe' LBA is completed in June.
4 Yes, sir.-
5 RDlR. OKRENT:
I am going to pursue the point on 6
your screen and frame it in a certain way.
~
And on the bottom of'this unnumbered page it says 7
[
8 after something has' passed some initial screening. criteria, 9
which we can-ask is this relevant mostly.
10 It says:
{
11 1
.One, will the core melt frequency goali
[
12 established in the EPRI requirements document be exceeded as 13 a result of this issue?
'14 Two, will the offsite accident radiological i
15 consequence, dose limits, established in'the requirements 16 document -- and I am not sure what those are -- be exceeded 17 as a. result of this issue?
18 Three, would the Commission's safety goal limits 19 be exceeded as a result of this issue?
20 I would maintain that many, if not most of the 21 safety improvements that the French and the Germans have 22 chosen to put in existing reactors and that the British have 23 proposed to put in Sizewell B, if it is built, would fall 24 these criteria.
O.
25 Therefore, the Staff would say, I assume, these ACE-FEDERAL REPORTERS, INC.
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need not be considered for ABWR, contrary to opinion of ms 2
sophisticated LWR countries elsewhere.
3 It seems to me if I am correct one, as a minimum, 4
has to understand why the Staff would adopt such a 5
position.
6 MR. CARUSO:
The Staff decided to start 7
somewhere, and the procedure that the Staff chose to start 8
with was the procedure that is being used in the EPRI 9
prcgram.
10 That procedure has already been published.
It 11 has been reviewed by the ACRS.
12 DR. OKRENT:
For what purpose?
I am sorry.
h, (J
13 MR. CARUSO:
I understand you reviewed 1197.
14 MR. HERNAN:
Not true.
15 MR. CARUSO:
I apologize then.
That is where 16 this procedure came from, and as I say, we are here to ask 17 for your comments.
18 DR. OKRENT:
Well, I am suggesting in fact that 19 before you bring this into the Commissioners or to the 20 committee for some kind of final review, you take a look at l
21 t a large family of improvements that have been either 0
22 !
implemented -- I will just mention France, Germany, and I
23 England -- or are proposed for implementation in the case of I
Sizewell B, place them against your test and make the 24
-( )
25 necessary estimates and see what you get out.
I I
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Then the second thing is tell me how s
2 uncertainties are factored into this screening process.
3 MR. CARUSO:
I think we would be using the 4
methodologies that would come out of the severe accident 5
policy statement documents.
6 DR. OKRENT:
Which methodologies?
7 MR. CARUSO:
There is going to be included in 8
this document acceptable methodologies for doing 9
probabilistic risk assessments for severe accidents.
10 DR. OKRENT:
It is not going to include external 11 events as a minimum, and there will be certain kinds of 12 internal phenomena which are excluded from the internal n
(,)
13 events.
14 So I don' t know what you mean when you tell me --
15 if you really think that those methodologies are it, I 16 suggest you review the situation again.
17 MR. MICHELSON:
Could I follow up on that?
18 I have a considerable concern about what 19 constitutes a new issue.
I believe we discussed this at the 20 l subcommittee, and you are going to go back and do some l
21 I thinking on the definition.
22 MR. CARUSO:
I have got some information for 23 ;
you.
1 24 MR. MICHELSON:
Okay.
Well, the important thing 25 g is to make sure that issues which are already on the table, t
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'well understood, but not necessarily yet prioritized are 2
carefully considered as to whether they are included or 3
not.
4 For instance, the question of system interaction, 5
which is a resolution that is on the table now.
A portion 6
of that resolution says we understand the problem now, we 7
are going to create a '.iew issue to tackle, which means that 8
the issue is already well identified.
It is just going to 9
get a new issue, reprioritizing, and so forth.
And that 10 will not be included.
11 And the reason for the concern that I have is 12 that we are using heavily solid state electronic controls jD(-)
13 for this plant.
The system interaction concern is the 14 spatial interaction between the loss of the water chillers 15 that keep this equipment cool and the response of the 16 equipment to the loss of coolant.
17 This kind of interaction would not necesssarily 18 even be considered because it is not yet prioritized, 19 although it is well understood, it is identified and 20 everybody understands what the problem is.
We just haven't 21,
prioritized it.
22 So under your rules, since it was passed last i
23 l July it would have to pass all these other.
l 24 '
MR. CARUSO:
Let me give you some information.
4 i
25 Every issue that had been identified, given a number, ACE-FEDERAL REPORTERS, INC.
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whether it was prioritized or not, every issue that was 2
identified in the NRC' tracking system was considered as of 3.
July 1st, 1986.
4 MR. MICHELSON:
Now, what happens to the new 5-spinoff issue because you only solved part of this number --
6 what is it, A-17?
7 MR. CARUSO:
Every new issue that is entered into
~
8 the tracking system, which means it has got a number,~will 9
be considered under this criteria.
10 DR. OKRENT:.It will be screened.
11 MR. CARUSO:
It will be screened.
It will go 1
12 through this process.
13 MR. MICHELSON:
And it has to pass all of these t
14 hurdles?
15 MR. CARUSO:
Yes.
16
- MR. MICHELSON:
Even though it is a spinoff from 17 one that you couldn' t get resolved.
You resolved only a 18 part of A-17 and the rest of it is going to become a new 19 number.
When it becomes a new number, it has now got to 20 pass the hurdles, even though we all understand what the f
21 issue is.
22 DR. OKRENT:
For a plant looking for a 23 certification about four or five years from.
l~
24 MR. HERNAN:
Carl, let me say a few words.
I i O 25 hate to repeat myself, but the real issue that you are i
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attacking is part of the EPRI program, which we fully 2
intended to have a subcommittee meeting this month.
We 3
found it necessary to go back to EPRI with a number of 4
questions.
That has been deferred about two months.
5 The screening process has been used by the Staff 6
and EPRI mutually for about three years now to get to where 7
we are.
ACRS has been briefed at least twice on what this 8
process is.
9 We are heavily committed to such a process.
It 10 is necessary to provide stabilization in the regulation 11 process.
12 We are looking for ACRS comments relative to the r~,
(
13 review of what is going on in the EPRI effort, on whether 14 the screening criteria are appropriate or not.
15 In terms of ABWR, I think the issues you are 16 concerned about will be fully aired in terms of the 17 technical review as applied to this particular design.
I 18 feel the ACRS will have ample opportunity to pursue that.
19 We do not intend to bury valid technical issues 20 and say, no, we can't consider those.
We have to consider 21 !
all safety issues.
22 MR. EBERSOLE:
The validity is the question.
4 23 That was the catchword there.
The validity could be an 24 issue previously identified, discussed, and then dismissed, O
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25 perhaps largely on the basis that it represented an ACE-FEDERAL REPORTERS, INC.
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expensive backfit to a preexisting plant.
2 That problem is no longer with us.
3 I see the heavy hand of lawyers here all over the 4
place with a precedent type thing.
The precedent thing is 5
we hope, without recognizing it, this is a new plant still 6
on the board, and Ne are going to do things we never did in 7
the backfit program.
8 MR. CARUSO:
Well, as I say, every generic issue 9
is being considered through the EPRI program.
NUREG 10 considered every one of them that existed.
11 MR. EBERSOLE:
But I see here, for instance, you 12 say you will not consider it further as having any impact on fs
(,)
13 the construction if it has been previously identified or 14 prioritized -- at the bottom of that page.
15 MR. HERNAN:
If it has been determined by the 16 Staff to not be appropriate to this plant design, yes, it 17 will not be considered.
18 MR. EBERSOLE:
No, no.
I am taking parenthetical 19 one.
If the answer to any of these following questions is 20 yes, then the issue will not be considered further.
21 MR. CARUSO:
Does the issue duplicate an issue 22 previously identified or prioritized?
23 MR. EBERSOLE:
And of course it could duplicate 24,
it, but the entire solution could because it has been
(
25 compromised by the fact that you had to rebuild the entire ACE-FEDERAL REPORTERS, INC.
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plant to accommodate it.
2 MR. CARUSO:
I think we will be reasonable in 3
applying that criteria.
.4 MR. MICHELSON:
Appendix R, and so forth, only 5
applies to old plants.
6 MR. EBERSOLE:
Of course.
All of Appendix R.
7 Appendix R is a case in point.
8 DR. OKRENT:
Can I ask, do you have more 9
viewgraphs to show yet?
10 MR. CARUSO:
I think I just have one more.
t 11 DR. OKRENT:
Would you do it because we want to 12 have the last 30 minutes for the last topic.
(~'/
s
(-
13 (Slide.)
14 MR. CARUSO:
In the way of ACRS support, we would 15 like to have your views and comments.
We are certainly I
16 getting them today.
17 DR. SHEWMON:
Only some of them.
Just wait.
18 (Laughter.)
i 19,
MR. CARUSO:
We had hoped to go to the Commission 20 with an LBA in late March and we had hoped to have your 21
' comments before we went to the Commission.
If that is not 22 possible, we would like to have committee or individual 23 comments as they would be available.
i 24 There is no need -- there is no hard schedule for 25 your comments or the Commission comments because the LBA is i
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.not scheduled to be completed until-June.
So there would be 2
time to incorporate and consider those comments in the' final 3
document.
4 I just wanted to state that.
5 DR. REMIC K:
A couple of minor things.
6 In your Section 11. 2 on the CPML regulations 7
-there is a very definite statement there that future utility 8
applicants who reference the ABWR design will be required to 9
provide plant specific simulators.
10 What I am suggesting here, I think that is 11 inconsistent with Part 55 that is just about ready to come.
12 out.
I think you want to make sure that that is 13 consistent.
14 I don't think it is necessarily a specific 15 requirement, although in practice it works out to be that.
1 16
!k) I think you ought to look at Part 55.
17 Along another line on Section 13.6, on the l
18 rulemaking, you have a very specific thing there that says:
19 "As a condition to participating 20 in a hearing, however, Intervenors 21 would be required to state the
[
22 issues they wish to have considered 23 at the hearing and commit to 24 providing expert testimony on those l
25 issues."
1 ACE-FEDERAL REPORTERS, INC.
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On several occasions, the committee has talked to 2
the Commission about the fact that how the rulemaking will 3
be conducted has not been very clearly specified in the new 4
policy statement on standard plants and urged the Commission 5
to give thought to being as specific as they could.
6 You are being more specific here than I think 7
they have been to date.
8 MR. CARUSO:
I can only comment to say that 9
Section 13 is consistent with the current Staff draft NUREG 10 on standardization which is before the Commission for 11 consideration.
12 DR. REMICK:
That could be.
I haven't seen it.
(~')
(_/
13 In that the Staff has been a little bit more 14 specific perhaps.
If it is consistent, that is all I am 15 asking.
16 MR. CARUSO:
It is.
17 DR. REMICK:
The last time I saw it, it was not 18 thrt specific.
It had gone beyond the standard plant design 19 !
certification policy.
I 20 '
MR. CARUSO:
Right now that section is 21,
consistent, and it will remain consistent with whatever the I
22 i Commission finally approves.
DR. OKRENT:
Would an Intervenor be abl6 to raise 23 an issue that the LBA had been identified as a nonissue?
24
<n k>
25 MR. CARUSO:
Since the LBA does not have a legal ACE-FEDERAL REPORTERS, INC.
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' standing, I don't see how the LBA would come into a 2
hearing.
An intervenor would.have'to show that'a regulation 3
had not been complied with. 'That would be the operative.
4 DR. OKRENT:
You have to show that a regulation?
~5 MR. CARUSO: 'The 'LBA does not relate to a 6
regulation.
7 The standards for admitting contentions would 8
have to be complied'with.
.That is in Section 2.
I would 9
have to look that up.
10 I mean, you are asking an off-the-cuff legal 11 opinion.
j i.
12 DR. OKRENT:
All right, let it go.
i
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13 I think we had best' move to the next topic, which 14 was intended to serve not as something we try to solve today 15 but just as a topic which might or might not be easy to 16 handle with an LBA.
17 I think the way we have this set up, GE is on 18 first.
19 MR. SAWYER:
Before I put my chart up, let me 20 mention a couple of things.
21 One is that as part of the EPRI program we are 22 right now in the throes of defining reasonably precisely 23 what the severe accident requirements for light water 24 reactors should be, and those will be coming through NRC for O
25 review, and so these kind of things are being dealt with ACE-FEDERAL REPORTERS, INC.
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not just by General Electric but by utilities as a whole.
2 To date, we have received some guidance from the 3
utilities on their wishes, and they are represented in 4
Chapter 1.
That is already before the Staff for review, and 5
Dr. Okrent referred to those two, which I will briefly state 6
as follows.
7 The requirements in those documents say that core 8
damage probability for a new plant should be less than 10 to 9
the minus 5, which is a little more specific than the goal 10 that came out of the Commission statement, which doesn't 11 partition the 10 to the minus 6 into how much is core damage 12 and how much is containment integrity.
T's
( ',
13 l Furthermore, it goes on with a second tenet, 14 which says that in any event don't have more than 25 rem at 15 half a mile from the plant for events that are calculated to 16 be greater than 10 to the minus 6 probability.
17 Now, that is an easy statement to make.
We are 18 in the process with EPRI and the Staff of trying to define 19l:
what the methodology is that is used to measure those, and 20 i we are in the throes of doing that, too.
21 ;
Nonetheless, there is an attempt in the EPRI 22 i program to define what requirements new plants should meet.
l 23 f DR. OKRENT:
Excuse me.
This is 25 rem over some i
24 l period?
rs
(
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t 25 i MR. SAWYER:
Forever.
It is 25 rem whole body ACE-FEDERAL REPORTERS, INC.
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integrated over all time.
2 (Slide.)
3 Of course, along with that number has to go a 4
methodology for how you calculate numbers like that, what 5
kind of weather you use, et cetera, et cetera.
The rules 6
for that analysis are being defined, but it is our 7
presumption that they are reasonably similar to the-kinds of 8
analyses which we did in GESSAR in the PRA we provided.
9 DR. MOELLER:
How does that correlate with the 10 safety goal?
11 MR. SAWYER:
I think it actually goes beyond the 2
12 safety goal, which at this point just says 10 to the minus 6 13 for significant release, or some words to that ef fect.
14
" Substantial release" I think is the words that 15 is used.
16 17 18 19 i
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21 22
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1 Let me turn from EPRI's program to General 2
Electric's opinion.
Our design philosophy on containment, 3
severe accident capability, although the agenda says 4
filtered vents, I think we're happy to entertain this 5
discussion now.
As Dan Wilkins mentioned, this is probably 6
one of the stickiest issues that the whole advanced light 7
water reactor program is going to deal with.
8 We really need to try and understand what the 9
rules in this area are going to be and give guidance up 10 front, because it has the potential for significant economic 11 impact, much less plant layout and other considerations, 12 depending upon what's decided upon.
n k-)
13 But let me at least acquaint you with the 14 philosophy behind what we're doing.
15 DR. MOELLER:
Excuse me.
Economic impact.
Can 16 you give us an estimate because we've had estimates from 17 others.
18 MR. SAWYER:
Well, we don' t know very much about 19 the gory details of that design, for example.
But we 20 understand that that particular solution is the order of $20 21 million or so, and that's at a location which is not a high 22 seismic location.
And for a smaller power level plant.
23 So I can only guess what trying to meet a 24 requirement to implement a design as complex as that for a 25 standard site in the U.S.
is likely to be several times ACE-FEDERAL REPORTERS, INC.
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_DR. OKRENT: ~ I wonder if that's the whole story 3
though.. You ought to give an estimate of.what 'the French 4
are spending for their PWRs, the balance of the story, 5
shouldn't you?-
6 MR. SAWYER:
Yes, I should.
I think we're 7
jumping ahead a little bit.
But, as long as we're on the 8
topic of filtered vents, I suspect that the approach that 9
was implemented at Warzbeck in Germany is probably the least 10 expensive of all the options that are being offered to date.
- 11 '
I'm not acquainted with how much that is, but 12 certainly an order of magnitude at the least less investment
(
13 than what was done at Warzbeck.
14 I do understand the Swedes are now saying-that 15 the next one they do in Sweden isn't going to be as 16 expensive either.
So it's an ongoing process, you're 17 right.
There is a balance to be struck here, and that's 18 what we're trying to achieve, too.
I 19 It's our view that a dedicated system for a 20 filtered bed isn't necessary.
Let me carry you through why 1
21 we believe that.
22 MR. EBERSOLE:
As you get into that, the very 23 first topic, the very first bullet, in order for you to 24 claim that 10 to the minus 6, you have had to reach out and O
25 invoke a recovery of comparatively heavy AC pumping power ACE-FEDERAL REPORTERS, INC.
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if you've lost it.
Over-pressure simply by heat 2
accumulation in the suppression pool design.
And you've had 3
to reach out and grab something, which I think is recovery 4
of the AC power sources to get the pumping system going 5
again.
6 In doing that, in that philosophical step you 7
took, apparently you then said, with that sort of 8
philosophy, I don' t need to retain the open cycle process 9
represented by UPPS, which is extremely cheap and simple.
10 I find a conflict right there with the first 11 bullet in this context.
You've got that to 10 to the minus 12 6.
And built into that is a philosophy that you want to get
/(_)
13 power back, if I've lost it, or I never lost it anyway.
14 There's nothing in this design I see that enables 15 this plant to recover from that situation, with a purely 16 mechanical and relatively low horse power.
17 MR. SAWYER:
Let me address that.
In our 18 preliminary evaluations of risk assessment for the ABWR, in 19 achieving what we believe is less than 10 to the minus 6 20 probability of core damage, that number did not assume any 21 credit for recovery.
Okay?
22 !
First of all, we're just talking about 23 prevention.
When you talk about recovery, we're talking 24 about mitigation.
25 !
MR. EBERSOLE:
You're talking about prevention of ACE-FEDERAL REPORTERS, INC.
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core damage.
2 MR. SAWYER:
In the prevention alone of core 3
damage, we believe we've achieved a number like that 4
primarily through the reliability and the number of systems 5
and number of options to solve the various threats.
6 MR. EBERSOLE:
This is all, however, dependent on 7
the persistence of the recovery of AC power.
8 MR. SAWYER:
The most dominant sequence that we 9
have for the ABWR, in our opinion, is the loss of off site 10 power threat.
11 And the dominoes that fall over, that get you to 12 that sequence.
Or you lose off site power, you lose all
(')/
13 three diesels of on site power and your steam-driven system s-i 14 fails.
15 Okay, if you count up those number of dominoes 16 and go through the exercise, at least consistent with the 17 methodology which we've done on other PRAs, the kind of 18 number you calculate for that sequence is less than 10 to 19 the minus 6.
20 l Now that's not to say that an aux system, if you 21 had one, would be even better.
22 MR. MICilE LSON:
Your steam system doesn't remove 23 heat.
24 MR. SAWYER:
No, the steam system doesn't remove 25 heat.
That's another event.
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1 MR. MICHELSON:
It's not another event on loss of 2
off site power.
If you don' t get the power back in time, 3
pumping water isn't going _to do you any good.
4 MR. SAWYER:
But I'm saying to you that it is 5
more likely in the risk assessment that you don't have the 6
pump available at time zero.
Then you have it available at 7
time zero and sometime later, you have a heat problem.
- Yes, 8
that also is a possibility.
9 But that doesn't dominate the sequence.
The 10 sequence that is the most troublesome is you don' t have your 11 pumps at time zero.
You're right.
Once I solve that 12 problem, if I can make that problem go away, the next 13 obstacle I f ace is what do I do about the heat?
Which is 14 further downstream.
15 MR. EBERSOLE:
And in that further downstream, 16 you must be invoking recovery of pumping power.
17 MR. MICHELSON:
You have to.
18 MR. EBERSOLE:
And that's the crux of it.
19,
MR. SAWYER:
Yes, that's right.
You are 1
20 correct.
In that regard, we've taken credit for recovery of 21 l off site power to the 95th percentile or something like that 22 within 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.
23 MR. EBERSOLE:
And the rational basis for that 24 comes up as a problem.
(
25 '
MR. MICHELSON:
Can he stand 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of loss of ACE-FEDERAL REPORTERS, INC.
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. coolant with solid state controlled dev' ices, and so forth?
2 Do you ever get recovery 'back?
3 MR. EBERSOLE:
By the way, the temperature rises, 4
an aspect to the_ equipment.
It's not helped by the steam-5 driven equipment.
6-MR. MICHELSON:
I'm not sure that -these 7
probability numbers include loss of ventilation and the i
8 effect on solid state.
9 MR. EBERSOLE:
I can see a number of problems 10 here which are not a part of this simple, open-cycle-i 11 system.
12 MR. SAWYER:
We appreciate your comments, don't 13 get me wrong.
I'm trying to outline, however, the way in 14 which we would prefer to spend our money.
Okay?
4 15 If you perceive that there's some vulnerabilities-16
.that we haven' t addressed so that that isn' t being achieved, 17 then we should address those.
18 MR. EBERSOLE:
The money I'm talking about can't 19 even be found in the noise.
20 MR. WYLIE:
Let me ask a question.
Do you not 21 though have additional redundancy in your normal decay heat 22 I removal capability and diesel generators over, say, 23 GESSAR-2?
24 MR. SAWYER:
Yes, we do.
25 MR. WYLIE:
So there's additional redundancy ACE-FEDERAL REPORTERS, INC.
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here.
2 MR. MICHELSON:
I'm not sure --
3 MR. WYLIE:
He's shaking his head.
,Let me ask a 4.
question.
Can you remove any component safety systems out 5
for maintenance and still meet single failure?
6 MR. SAWYER:
Yes.
7 MR. EBERSOLE:
He's got three tracks.
8 MR. WYLIE:
So, I mean, you know, there's 9
additional redundancy.
10 MR. EBERSOLE:
He's tacked on an increment but he j
l 11 hasn't invoked diversity and simplicity.
l 12 MR. MICHELSON:
The power is lost to all three f')
(/
13 trains.
14 MR. WYLIE:
In effect, you've got N plus 2 in g
I l 15 your design.
16 MR. MICHE LSON:
I don' t care how many N 's you've j
17 got, if you lose power in all of them and it heats up --
18 MR. WYLIE:
You've got to buy something or you 19 don't do it.
20 i MR. SAWYER:
Let me proceed because, otherwise, 21 the staff won't have time.
22 I DR. OKRENT:
Mr. Shewmon had his hand up, 23 however.
l 24 '
DR. SHEWMON:
Are you on that next -- mitigation
~
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25 of overpressure yet?
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MR. SAWYER:
I'm about to get there.
2 DR. SHEWMON:
Tell me what metal is included in 3
MWRs.
Just the cladding?
4 MR. SAWYER:
It's the fuel cladding itself.
In 5
the PRAs that we've done, and that others have done 6
also, itindicates that, in actuality, the quantity of 7
hydrogen generated by the time the core is on the floor is 8
the equivalent of only half of the cladding, not of all the 9
zirconium in the reactor.
10 So this is a substantial increment beyond that.
11 DR. SHEWMON:
I know, but if you pay attention to i
12 the severe accident research, the people who do those
()
13 calculations are now upping the estimates they have.
And 14 your estimate may not be what they've given today.
15 The other question I wanted for information is, 16 the cladding is part of the zircalloy in your core.
What 17 fraction of it is?
Because you've got your channel walls 18 are ziralloy, too?
19 l MR. SAWYER:
The channel walls are, too.
So l
20 i there's about half is cladding and half is channel.
And 21 i there's twice as much zirconium in the core as there was in 22 l the fuel cladding.
23 i And I was going to say there are other things 24 which have the possibility, given the right conditions, to
(
)
25 I create hydrogen also.
ACE-FEDERAL REPORTERS, INC.
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(~/ DAV/bc-1 DR. SHEWMON:
Stainless steel will burn if you 2.
get it hot enough.
.3 MR. SAWYER:
So, at some point, you have to reach
'4 out and pick a target and say this is the basis and this is
.5 what we've done.
6 In any event, we prefer to spend our resources 7
here first and down here last.
So this is our priority:
8 prevention in the mitigation.
We've addressed some things 9
in the ABWR design that se think answer some of the concerns 10 on our existing containments.
11 We are' planning to demonstrate no early failures, 12 predominant sequences, and the major one of those is ATWS.
13 And we've done that primarily through diversity in the 14 drives that we're applying to this plant.
15 We are designing for a combination of more 16 noncondensibles than previous plants, and we have an extra 17 increment of heat removal for prevention of containment over 18 pressure.
-19 We've taken a direct frontal attack on hydrogen 20 '
burning by basically using an inert atmosphere.
And the 21 other way in which you can get into trouble with 22 containments is the core debris attack on the containment 23 boundary, and our attack on that front is the division of 24 two divisiens of drywell sprays.
25 In any event, going beyond mitigation, we are I
ACE-FEDERAL REPORTERS, INC.
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incorporating into our design philosophy the philosophical 2
process which will lead to retention of the suppression pool 3
if, and when, you ever get to ultimate failure.
4 What that means basically is we are planning to 5
demonstrate that the containment fails in the wet well air 6
space.
And that the dry well and the suppression pool are-7 stronger than the wet well.
8 That's an important feature because that provides 9
you with a filtering path for fission products which 10 initiate the possibility of getting out in the dry well.
11 And we're going to pay a lot of attention to 12 detail, as we have in GESSAR and other plants to make the
\\_-)
13 possibility of bypass highly unlikely.
14 One of the subjects that was raised yesterday, 15 for example, what are we doing about wet well/ dry well 16 vacuum breakers?
What are we doing about safety relief 17 ialve discharge piping, and so forth?
18 And all of the likely ways in which it's possible 19 that the fission products can get to the outside world, 20 getting around the pool.
21 A fourth tenet of what we're doing is, in any 22 event, the plant has provisions for a vent that means that l
23 the 10 CPR 5034(F) rule that says:
Please make sure you 24 don't rule out the possibility for regulatory insistence on
~
25 event -- we have accommodated that by keeping room for it.
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MR. EBERSOLE:
That vent (hough is particularly 2
characterized as a post-core melt vent, isn't it?
3 Therefore, it's large.
It's got to perform under. duress of 4
all sorts.
It's an expensive vent.
5 MR. SAWYER:
We haven' t engineered it at this 6
point.
All we've done is left a provision for it.
7 MR. EBERSOLE:
It's a different caliber than a 8
pre-core melt vent, an entirely different caliber, far more 9
complicated and expensive and difficult to rationalize the 10 use of.
11 MR. MICHE LSON:
It's not a heat removal vent?
12 MR. EBERSOLE:
No, it isn't.
, ~.
13 MR. SAWYER:- It's a pressure relief vent, that's
~
14 right.
15 MR. EBERSOLE:
I want to separte that kind of 16 vent from the other kind of vent and say that one is chicken 17 feed and the other is not.
18 DR. OKRENT:
Well, I think it's relevant to 19 observe that an increasing number of countries seem to be 20 unwilling to assume that the so-called slow failure mode of 21 containment is preferrable to a controlled filtered 22 release.
l 23 If you're in an accident that is threatening this i
24 over-pressurized failure of containment, you may say this is O
25 a matter of judgment.
I guess my own judgment if I were the t
l ACE-FEDERAL REPORTERS, INC.
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governor, the president, I would much prefer to have the 2
ability to have the controlled release and not the concern 3
that, as this pressure creeps up, I don' t really know quite 4
how precise we know the failure point or the failure mode, 5
when you're getting to ultimate or near ultimate.
6 And I'll just observe that we see an increasing 7
trend that way.
And I, myself, think that a philosophic 8
approach by either the industry-or the NRC in this country 9
that's counting on getting up to near ultimate or even 10 through ultimate is going to be a short-lived philosophic 11 approach.
12 MR. EBERSOLE:
In either case, modulated relief 13 certainly makes more sense than control.
14 DR. SHEWMON:
You want a rupture disk down there.
15 MR. SAWYER:
Your comments are well-taken.
We 16 understand that there are countries that are concluding that 17-venting containments is the thing to do.
18 One of the reasons why it's on the table now is 19 because, at the present time, the United States doesn't have 20 a position.
And one of the things we were getting on the 21 table right now is:
22 What should the United States position be?
23 My own judgment is that we're arguing in an area, 24 personally, we're taking on an issue with the presumption 25 that the core is on the floor and that's going to happen.
ACE-FEDERAL REPORTERS, INC.
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(m)' DAV/bc l-And that's going to happen next year or the year after.
2 A lot of people, I think, since Chernobyl, have 3
at least philosophically left from this 10 to-the minus 6 to 4
10 to the minus 1.
And I think, in deciding how much to 5
spend in this area and whether it's worthwhile to do it.
6 One of the things that has to be considered, I 7
believe, is are we going beyond what's really necessary?
8 MR. MICHELSON:
Was the core always on the floor 9
before the containment can potentially be destroyed?
10 MR. EBERSOLE:
No.
11 MR. MICHELSON:
Not necessarily.
We're not 12 necessarily in a scenario where the core is on the floor.
}
13 And this is the last resort.
14 The core may be in good shape until the 15 containment blows.
You lose your penetrations and the core 16 melts.
17 MR. SAWYER:
That's a dif ferent kind of event.
18 MR. MICHELSON:
But it's still on the list.
f l
19 MR. SAWYER:
Because I don' t think that you'll 20 have trouble getting the governor of a state to sign up for 21 steam releases that are clean.
22 23 24 i
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MR. MICHELSON:
It's an overpressure.
2 MR.. SAWYER:
The. difficulty you have is the 3
terrible decision that has to get made of whether to attempt 4
to try and keep retaining fission products, or whether to 5
deliberately release them.
6 MR. EBERSOLE:
Don't you think it's the NRC's 7
responsibility to take on a long overdue problem, which is 8
to strike a balance'between radiation release, to prevent 9
worse release?
And hand it to you?
10 DR. OKRENT:
Jessie, I'm going to ask that we use 11 the remaining seven minutes to let the staff get up because i
12 I only have 'til quarter of.
And that's not quite seven r^x d
13 minutes.
14 So let me thank General Electric for opening up 15 the subject and giving their current point of view.
Let's 16 hear what the staff has to say.
17 MR. CARUSO:
Well, I think it's been pretty much 18 stated already that the staff doesn't really have a firm I
19 position on filtered vents.
In some cases, at some plants, 20 we have taken the position that there should be vents 21 installed on containments.
22 The ABWR design though hasn't been presented to 23 us.
And without any more information, it's really difficult 24 for us to establish a position one way or another.
25 The only thing I can say is that, in the past, we ACE-FEDERAL REPORTERS, INC.
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have taken a position in favor of uncertain plants, and it's 2
possible we may decide that, that that may be the way to go 3
for the ADWR.
4 But, right now, we don't.have a position on it.
5 MR. MICHELSON:
Why did you state a position in 6
the licensing basis agreement?
It says:
There will be 7
filtered vents on the containment, in Section 1.2.
8 MR. CARUSO:
Well, that was the thinking at that 9
point.
10 MR. MICHELSON:
You had a position at that point 11 and now you do not have a position.
Is that the situation?
12 MR. CARUSO:
It's not been completely firmed up.
1 13 MR. EBERSOLE:
Isn't that due to the fact that 14 the ground rules for using it are not present?
15 DR. OKRENT:
I don't know that that's the basis..
16 MR. CARUSO:
I think there is also a little bit 17 of confusion because when it was drafted up, we may have 18 understood that G.E. was providing a filtered vent.
And now 19 there is some disagreement.
20 MR. WARD:
That's strange.
You were going to 21 require it if they were offering it, but not required if 22,
they weren't offering it?
i 23 MR. EBERSOLE:
It sounds like it.
24 MR. CARUSO:
The wording, as has been noted OG 25 before, in some of the sections was a little bit unfirm.
I ACE-FEDERAL REPORTERS, INC.
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MR.-WARD: 'Let me ask you this.
Three-foot 2
opening.
Is that intended to be consistent'with the-type of 13 filtered vent that the' French and the Germans are~ including, 4
which is just to protect against late containment failure?
.5 It'doesn't do any good at all for early containment' failure?
6 Is the three-foot diameter hole, or whatever it's 7
- supposed to be, you know, intended to provide for a. vent 8
that would offer some protection against early' containment i
9 failure?
10 MR. CARUSO:
I really can't_ answer that 11 question.
I don't know what the rationale was.
12 MR. WARD:
Does_anybody know?. Do you, Dave?
~
13 DR. OKRENT:
I think it's a smaller hole than the 14 three-foot-that'the-Germans and the French use.
15 MR. WARD:
That's something that I think, in our 16 discussions, that we need to make very clear.
For: example, 17 the Warzbeck design, do you know what that is?
18 DR. OKRENT:
Warzbeck is for a BWR.
And I don't I
19 know what design or load basis it is.
That's a fancy, fancy
[
20 filter, you have to understand, in which the intent is to 21 capture, I think, not only everything --
i 22 MR. WARD:
But the ability to filter is one 23 thing.
But the capacity, whether it's intended to do 24 something for early failures or just late failures, is a big
[
25 item.
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DR. OKRENT:
If there's a hole in the containment a
2 the size of a door, it's hard for a filter to compete unless 3-you've got a great big blower pushing the material into the 4
filter.
And I haven't seen any designs like that except in 5
university beasts, of which there was one at UCLA.
6 But if you're talking about trying to prevent 7
failure by slow or sudden overpressurization, that's an 8
issue I think that is design-dependent and 9
accident-dependent.
10 The argument here is that the chance of ATWS is 11 very small.
12 I have around 30 seconds.
Could I ask one 13 question of G.E. just for my own education?
14 It used to be ala Oyster Creek and before that i
15 there was a 100 percent relief capacity, I think, in 16 reactors and then the pressure vessel, where it was 17 changed.
18 So, at Dresden, there were only a few safety 19 relief valves.
I mean, I'm talking about turbine bypass.
20 MR. SAWYER:
There's 100 percent relief capacity 21 in this plant through the relief valves.
i 22 DR. OKRENT:
The ABWR doesn't have 100 percent as 23 I remember.
24 MR. SAWYER:
Yes, it does.
We have 18 safety 25 relief valves.
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DR. OKRENT:
It has 100 percent relief to the 2
suppression pool?
3 MR. SAWYER:
Yes.
4 DR. OKRENT:
Therefore, would you argue that 5
given an MSIV closure suddenly, you won't get much or as 6
large a pressure transient, and that that the ATWS is not as 7
severe?
Or how does that turn out?
8 Let's forget --
9 MR. SAWYER:
The answer comes out very close to 10 the.BWR-6 answer, which also has 100 percent relief 11 capacity.
In other words, the peak pressure that we 12 calculate, given a delayed scram, shall we say -- let's say
-(m
(_)
13 that the hydraulic scram failed and we are now counting on-14 the two-minute run-in for the dries.
15 The peak pressure will be less than 1,375.
16 DR. OKRENT:
Where does your power level end up 17 at, which is a key thing so far as the heat generation 18 afterwards in the load to the core?
Any different?
19 MR. SAWYER:
Philosophically, they're not the 20 same.
In other words, the actions that are taken to reduce 21 the power level are to run the recirculation pumps back and 22 ;
you get cooled down to natural circulation.
That gets you 23 to about 50 percent power to run the feedwater control 24 system back to deliberately lower water level.
25 And there is some debate over what that number ACE-FEDERAL REPORTERS, INC.
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is.
And, right now, through the studies done by EPRI and in 2
our owners group, there is some debate about how low a water 3
level should you permit yourself to go.
4 But, in principle, you can basically shut the 5
nuclear reaction off.
6 DR. OKRENT:
But the greater relief capacity 7
doesn't have a very big effect on residual power?
8 MR. SAWYER:
All that does -- no, it doesn't.
9 No, all that does is guarantee you get past the first 10 pulse.
But you then will drop to some quasi-steady state 11 power level, which you have to take some action on if your 12 backup scram also doesn't work.
k-)
13 You then have to take the action of getting your 14 liquid poison in because you can't stand but 15-20 minutes 15 of such high power levels to the pool before your pool is 16 too hot.
17 MR. EBERSOLE:
Do you invoke deliberate ADS 18 functions to get the pressure down, increase the void 19 fraction and help out?
Or do you just wait for the pressure l
l 20 to hel'p safety's?
t i
21 n MR. SAWYER:
There is no signal that says at the i
22 l front end this is an ATWS.
The transient is, let's say, 23 i MSIV closure.
At that point in time, you don't know whether i
24 j you have an ATWS on your hands.
(
)
l 25 i MR. EBERSOLE:
You'll know pretty quick.
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MR. SAWYER:
You'll know pretty quick.
s 2
And if you don't get your fast hydraulic scram at E
3 that point, you are depending on your safety's for your 4
overpressure control.
5 MR. EBERSOLE:.But you wait until they go up?
6 You wait until they get to high pressure and the void 7
collapses as a result.
8 MR. SAWYER:
I'm not sure where you're headed.
9 The safety is on there to guarantee that you don't exceed 10 the emergency levels.
11 MR. EBERSOLE:
But, in order to get to that 12 pressure, you have void compression.
-13 MR. SAWYER:
Yes.
- s 14 MR. EBERSOLE:
Are you open then?
Prior to 15 exceeding that pressure, you-reduce the power level?
16 DR. OKRENT:
Jessie, I'm out of time.
I'm only 17 trying to ascertain whether or not they had full bypass 18 capability, which they do.
And what it was.
19 MR. WARD:
Relief capability.
20 DR. OKRENT:
Sorry, relief, which is different 21 than some of the intermediate BWRs.
22 DR. REMICK:
I thank G.E.
and the staff for the 23 presentation, and Dave for managing it in the time so we 24 have approximately 15 minutes.
We'll take a recess until 11 O
25 o' clock.
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(Recess.)
2 DR. REMICK:
I suggest we proceed with our 3
meeting with the director of the office of the NRR, Harold 4
Denton, who is with us.
And for the staff who might be 5
going to be on the agenda for the safety goal _ policy, which 6
was scheduled for 1:30 to 3, I think we're running about a 7
half hour late.
8 So that will probably come about 2 o' clock.
Two 9
to 3:30 would be my guess, this afternoon.
10 Harold, we welcome you to join us.
For members 11 of the committee, under tab 3 are the four items which I 12 believe Harold has been alerted to as possible topics for m
s 13 discussion.
14 MR. DENTON:
Let me apologize for being late.
15 The Commission was meeting this morning on the safety goal 16 philosophy and the role of the ACRS in developing that
-17 policy.
18 In view of time, let me just quickly cover the 19 three points I wanted to cover and I'll cover any others 20 that come up.
21 I wanted to talk first about the Chernobyl 22 accident, and our response to that.
I think we briefed you 23 and you subcommittees a number of times on what we're 24 doing.
We finally have two reports in near publication 25 form.
We will be publishing within the next several weeks ACE-FEDERAL REPORTERS, INC.
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two reports.
One will be on interagency compilation of 2
facts about the accident that will deal with the causes and-3 effects of the accident.
4 That should be available probably by the next 2
5 time we meet, and we intend to send that out for general 6
comment.
7 That's heavily based on the information we 8
received in Vienna.
Dr. Kerr was there with us, on the NSAC 9
- report.
That was later released.
I have some copies of 10 that.
And on published literature about the accident.
11 The other report will be our assessment of what 12 the accident means for the NRC.
That's a totally in-house 13 document.
I've briefed you on that.
14 We also intend to seek-comment on that.- We've
~15 tried to incorporate in that document the ideas that you've 16 brought to our attention in discussions, but since we're 17 just writing a letter, I believe, this turn on that, we 18 probably won't cover all the details; plus we're having it
'19 published before we would receive it in a letter, instead of a
20 providing it after we've written the letter and gotten the 21 views of the Commission.
22 We've also labored mightily to coordinate our 23 efforts with the world at large in this area.
We've had a 24 lot of meetings with the French and the Germans and the
)
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this area, since we have similar reactor designs.
2 That's about all I wanted to say about the status 3
of the report.
Both reports will be available.
4 DR. REMICK:
Any questions on the Chernobyl 5
reports?
Dade?
6 DR. MOELLER:
One thing.
Is there anything in 7
the data relative to the reactions -- meaning the health 8
reactions -- of the people to whom KI was administered?
d
'4 MR. DENTON:
I don't think we've ever gotten that j
information.
That sort of information was on our IJ 11 agenda.
12 We planned a meeting with the Soviets.
You may 13 recall that Commissioner Bernthat had initiated the plans to 14 have a meeting the day before Chernobyl happened.
And since 15 that time, we've changed agendas and we have put on our 16 names on a list of people to attend the meeting --
17 individuals from NIH and DOE, who are health specialists.
18 They are very interested in those types of 19 areas.
I don't know if we'll obtain from the Soviets any 20 more details than they gave out.
21 DR. REMIC K:
Any other questions on that subject?
22 '
(No response.)
23 <
MR. DENTON:
Next I wanted to cover strategic 24 planning.
The Commission has asked the staff to develop a O
25 i long-range strategic plan.
It's a very important priority ACE-FEDERAL REPORTERS, INC.
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DAV/bc-1 to the chairman.
We've taken a lot of senior managers and 2
the staff trained them in what strategic planning is all 3
'about, and tried to work toward developing the plan.
4 We were very fortunate to have your input dealing 5
with long-term planning within the agency.- So we relied a 6
lot especially on the list of assumptions.
We will look at 7
those very shortly.
8 We have given the Commission one briefing on 9
strategic planning.
The intent is to complete the first 10 phase of this activity by the end of February and try to 11 develop what goals should be and what some strategies for 12 developing those goals would be, so the Commission can n/
s_
13 choose among those alternative strategies.
14 It's been useful I think for the staff to be able
-15 to sit back and take this longer term view.
We don't see 16 dramatic changes that would affect that.
We think we're at 17 the end of an era in NRC with regard to licensing.
18 Up to now, it's been largely organized to review 19 applications, review construction and design criteria, and f
20 so on.
We foresee that all coming to an end, as you well 21 know, and having 120 plants or so that will be in 22 operation.
23 Many of the new problems will mean interacting 24 with the federal government.
The high level waste area is a O'
25 federal government activity.
New reactor designs are a ACE-FEDERAL REPORTERS, INC.
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federal government involvement.
There's increasing state 2
involvement in the whole matter.
3 The states are asking to accompany us on 4
inspections and' attending enforcement conferences'and, in 5
some areas, are attempting to set more stringent standards 6
than the NRC.
7 So that's one area that we see as certainly being-8 more important.
So we're attempting to develop in a very 9
short time goals that the Commission would like to pursue 10 and strategies.
And given that report, I'm sure it's going 11 to take a lot longer than the time I'm talking about to 12 really get agreement on what they are and what the strategy I
\\_/
13 is.
14 The Commission is very anxious to get started in 15 this area.
Your efforts are very helpful.
16 DR. REMICK:
Dave?
17 DR. OKRENT:
Let me offer what you might call'an 18 anticdote as a way of raising a question and making a 19 suggestion.
20 There was a guy who was associate director or 21 general counsel of the FDA.
I can't recall.
It's not 22 important.
But he was at some meeting where people were 23 talking about risk management, and so forth.
And he said 24 that every year they asked themselves what do we think are 25 the most serious questions?
What does the public think are ACE-FEDERAL REPORTER 5, INC.
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'the most serious ~ questions?'
2 Where do we think we~can make the most impact
-3 with the resources that we have-available?
4 5
6 7
8 9
i 10 11 4
12
'13 14 15 16-i
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l 18 i
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21 22 23 l
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-1 They would take this cluster of information and 2
arrive at a strategic plan.
You can do it for a year or for 3
five years.
4 Why am I bringing this up?
5 It really isn't clear to me where this 6
question -- what does the public think is the most 7
important -- gets into the NRC's at least thinking, whether 8
you accept it or not.
9 The FDA didn't necessarily accept it, but at 10 least they asked themselves the question.
11' I will just leave it at that.
12 MR. DENTON:
A very good point.
("/
X i
A-13 MR. EBERSOLE:
Dave, I would like to comment on 14 that.
If we can have a public perception that we can stop 15 the reactor process, the scram system, and then we can 16 invoke'something -- as you know, I have been struggling, for 17 as an advocate in this ABWR, the concept -- which is 18 publicly understandable of an extremely simple open cycle 19 boiling that the public can perceive as no more than a 20 pocket just for steam and low pressure water, I think the 21 public perception would be turned around.
22 MR. DENTON:
We get a lot of public input.
23 t Yesterday I had calls from every elected official in the 24 State of North Carolina.
(
25 (Laughter.)
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MR. DENTON:
And what the public wants is no 2
possibility of a major release of reactivity in their area.
3 That is very clear.
4 DR. SIESS:
Is that the way you define the 5
public, Harold?
6 MR. DENTON:
Well, coming from ' elected 7
officials.
8 DR. SHEWMON:
They represent the public.
9 What halpened in North Carolina?
10 MR. DENTON:
Only that their plant is coming up 11 for licensing, that is all.
12 And we get a lot of input from Congress in this
(~h s/
13 area.
We think there will continue to be.
One of our 14 assumptions is there will continue to be divergent public 15 views on the need for and the safety of nuclear power 2
~
16 plants.
17 Public opinion changes very slowly, and big i
18 events can change it, such as Chernobyl.
But at the same 19 time, we are developing a plan, largely based on our present 20 perception of what is needed, for the NRC to do a better 21 job.
22 DR. OKRENT:
Let me pursue this for a minute, if 23 I may.
Of course,~I will be pursuing my not so hidden 24 agenda.
25 In fact, I think that is a broad public desire, ACE-FEDERAL REPORTERS, INC.
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the one you mentioned -- it is not just their-s 2
representatives -- that there be no large release from the 3
U.S.
reactors.
4 My own opinion is if they look at some kind of 5
. cost / benefit calculation, either the thousand dollars per 6
man-rem or this current matrix approach, and they say, gee, 7
is that what they are doing to decide this, then they would 8
say we don't think that is the way to go.
9 They tend to say, what is the best practicable 10 technology, the best practical technology, or something of 11 this sort, and I think the NRC is in a dilemma, whether they 12 know it or not.
(3.
)
(..)
13 They have got this backfit rule.
They have got 14 an industry pounding on them in one direction, and there are 15 not too many voices for what I think is really a very strong 16 majority of public opinion, which you say these 17 representatives from North Carolina said, and I think they 1
18 were -- I don't see right now that the NRC is being i
19 responsive.
20 In fact, I am concerned that those people who 21 might try to be responsive to that would be given other 22 offices.
23 I will leave it at that.
24 MR. WARD:
I think you have made a connection 25 there.
I mean, the last thing you said.
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I am not sure the activities of the people you
%s 2
are talking about were related to responding to indications 3
from the public of what is needed.
4 DR. OKRENT:
I'can't say that.
I do know that 5
after Chernobyl I heard a talk.on MacNeil-Lehrer in which 6
Ellen Weiss from UCS tried-ta) make the point that even 7
though the Chernobyl reactor was different from light water 8
reactors it is possible to have an accident involving a 9
large release from the light water reactor.
10 And the representative from the NRC who was on 11 that same program who happened to be the Executive Director 12 for Operations sidestepped that issue, leaving the public f--)
~
{
(d.
13 the' impression that from the NRC's point of view, you know, 14 we had containment.
15 MR. DENTON:
There has been in fact in some 4
16 people's minds that Bob Bernero and I are having a change of-l 17
' jobs, somehow having to do with advocating this change in 18 the Mark I.
19 DR. OKRENT:
It is in my mind --
20 MR. DENTON:
He and I have advocated and a lot of 21 others have advocated a lot of other changes.
22 There is no connection.
I began talking to the 23 Chairman about a new assignment at the Agency a long time l
24 ago before I started talking about the Mark I, and I think O
25 that is an invalid connection.
4 b
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When you think about a reorganization where a lot 2
of people get shifted, it is not over Mark I.
3 But this area of what does the Commission want 4
the safety goal of the Agency-to be is very important.
That 5
is what they are meeting on today, and the fact that there 6
were'no'early fatalities at Chernobyl, for example, yet it.
7 was labeled by the Soviets an economic disaster.
8 So I think there'are a lot of us regulators who
.9 are reconsidering what is the right definition of 10 containment.
Is it.something that doesn't fail early, fail 11 late?
Is there a possibility of remigration of nuclides?
12 Is there a possibility of bypass containment?
~
13 So that sort of thinking is going on.
But in the 14 role of strategic planning, we are going to deal'with things 15 that are more tractable, I guess, in a sense, and' set goals 16 where you get Commission input and develop strategies to 17 achieve those goals, if that would be possible.
i 18 DR. REMICK:
Harold, on the strategic plan, what l
19 time horizon are you saying -- five years, one year?
20 MR. DENTON:
Five years.
21 DR. REMICK:
Is it going to be tied to internal 22 budgeting for next year?
In other words, once you have a I
f 23 plan in place and goals set, will that be used in budget 24 planning or not?
C:)
25 MR. DENTON:
We are trying to untie it at the ACE-FEDERAL REPORTERS, INC.
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moment.
We think it is vital.
2 Think of it as a pyramid and define what the NRC 3
mission really is.
We h' ave our statutes.
Those can mean 4
various things.
5 So we think what we are doing is developing 6
overall goals, basic NRC responsibilities, and some specific 7
strategies by which those goals, specific goals may be 8
pursued.
9 Now, this group is going to drop that, and we are 10 not going to do the dollar-by-dollar work of developing 11 budgets which tie together those strategies and those goals 12 to actual budget implementation.
That is a much bigger
(/
13 effort than the group that has been put together can 14 handle.
15 So since you always have to do budgeting all the 16 time, once the Commission approves the overall goals, then 17 the total Agency budget should move over, and it does have 18 such concepts in there as increasing attention to material 19 licensing or the sort of goals that we see as increasing 20 l communication with the states and their increasing role in 21 l transportation of high level waste.
i 22 So it is in the early development stage, and you 23 probably have received somewhere copies of the first 24 briefing we gave the Commission, and they were very high O
25 l level goals.
l i
t l
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So we are now dropping down a level and trying to 2
develop more specific goals.
3 DR. REMICK:
I had a question while you were 4
addressing that before the Commission.
Is there a Steering 5
Committee that you are on?
6 MR. DENTON:
Yes.
I am Chairman of the Strategic 7
Planning Steering Committee, and that includes Erich 8
Beckjord, who tells us he did the first strategic planning 9
for Westinghouse, for example.
It includes Tom Murley.
It 10 includes some people from our resource management and a 11 number of other senior managers.
12 We had one meeting with industry representatives, 13 not to get any input on what NRC ought to be doing but to 14 find out what they do with regard to planning their own 15 activities.
16 So we got a major supplier describe to us their 17 efforts in regard to strategic planning.
18 So I think because of your interest in this I 19 just wanted to let you know that the effort is going on and 1
20 f it is in an embryonic stage.
21 DR. REMIC K:
Any further questions on strategic 22 planning?
23 (No response.)
24 DR. REMICK:
If not, your third topic, Harold.
(\\ )
25 MR. DENTON:
The third topic was the reliability l
t 8
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of auxiliary feedwater systems.
2 We had exchanged views on that area.
We made 3
several attempts to try to get closure in this area after 4
the Davis-Besse event. - I felt, I think, somewhat burned by 5
having someone sent out a PRA.
It takes a long time to 6
review to review the PRA, and it takes a long time to 7
straighten it out.
8 I wanted it to move ahead.
I took the approach 9
at wanting to take a stem-to-stern look at auxiliary 10 feedwater systems that we had concerns about, look at the 11 design and configuration of the plant and look at the way 12 that it had been maintained over the life, what are the G
lt/
13 operator training aspects, the procedures, the 14 instrumentation and controls.
15 So we plan to do that at those seven or eight 16 plants that we really want to focus on, and I think we'have
(
17 sent the committee a report on Prairie Island, which was our 18 first integrated look, to send out a five-person team that 19 had written a report.
l 20 We have concluded that that issue is resolved for l
21 the Prairie Island plant.
We have been to another plant, I.
I 22 '
think, and that schedule that we provided you to go to the i
23 other plants.
j 24 This is our way to take an integrated look at i
25 this thing and look at all the information that is l
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available and not just look at the PRA by itself.
2 MR. EBERSOLE:
Can I ask a-question, Harold, on 3
the topic of challenge frequency?
4 It would be my own position -- and as a matter of 5
fact, I was just writing a couple of improvements -- that 6
the aux feedwater system ought to be regarded as a safety 7
system whose challenge would be extremely aware and always 8
be reported out, and the feedwater should come from the main 9
feedwater rampdown so that you are never really on a turbine 10 trip, or whatever, never entered a region of the safety 11 equipment other than the scram itself.
The scram would 12 always be a retreat to a more conservative state without r%(-)
13 invoking the need for some new set of equipment to jump up 14 and save your day.
And if you got outside that boundary, 15 that was always reported and looked upon with considerable I
16 disfavor.
17 MR. DENTON:
That certainly is an interesting 18 comment.
19 MR. EBERSOLE:
Westinghouse doesn't do that.
GE 20 tries, but there is a random package as to how this is 21 done.
There is no set pattern at all.
There is no 22 philosophy.
23 MR. DENTON:
I think that is something we want to 24 consider in talking about advanced design.
2 5
'l Unfortunately, we are stuck at the moment with a l
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lot of two-train systems out there, and they are the ones 2
where this problem is interesting.
ft 3
DR. REMICK:
Dave Ward would like to address that 4
subject, also.
5 MR. WARD:
I guess, Harold, I was disappointed in f
6 the Staf f's response to our letter of last September.
We s'
7 felt this sort of thing had reached a level of maturity and n
8 we are entering an era where you are going to attempt to use 9
to a greater extent more objective criteria and quantitative 10 criteria for judging acceptability of those systems.
11 The original plan, this aux feed system problem 12 for the seven plants, you know, is not a new one.
It is f
13 sort of a mature problem.
14 I guess I was disappointed that you had to kind i
15 of revert to the old days methods for this, what seemed kind 16 of a potentially clear-cut application.
17 And I appreciate that you are under some time 18 pressure but you are going to have that time pressure in the
?
19 future as you more and more try to use objective criteria as i
20 '
opposed to the subjective opinions of often relatively low l
21 level people in the Staff.
22 4
MR. DENTON:
I knew that the committee wasn't 23 really pleased with the approach, and that is why I did want l
24 to be sure you got the first one we have issued, and perhaps 25 after you have had a chance to look at that we can meet l
l ACE-FEDERAL REPORTERS, INC.
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I again on the topic.
2 I actually think this particular plant didLhave a 3
PRA.
So we were able to use that, also, in the ' course-of 4
the review.
But I' guess from listening to the day-by-day-5' plant problems there are so many' things that contribute to 6
system failures, such as inadequate lighting in the area, 7
lack of accessibility to key equipment, improper training of 8-the people,.these things are very difficult to work into 9
PRAs and use sort of generic failure rates on PRAs.
10 You remember when Davis-Besse happened there were 11 a slough of things that occurred in that system, and that is 12 where the random failures had come, and our consultants had L
13 been talking about the feedwater systems.
14 It does seem ultimately that the technology is 15
-run by humans and you need some way to factor in how the 16 humans really are maintaining and operating the systems and 17 using sort of generic failure rates.
18 MR. WARD:
I don't disagree with that.
I think l
!19 the program of looking in detail at the systems as they sit, 20 as they operate, is useful.
But you are still not using any l
21 objective criteria in judging whether what you see with that i
22 detailed look is adequate, and I think that is the point.
23 MR. DENTON:
We might note, too, we didn't go 24 through a cost / benefit evaluation and used PRA in this 25 Prairie Island case.
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.1 What was identified wereuthings that would 2
further-enhance the system, and the_ licensee agreed to_do
?'
those things.
4 Once you-get in the PRA and you get into a 5
thousand dollars a man-rem and you try to consider _ generic 6
.backfit and show it is really justified, it'is an extremely 7
= laborious task.
8 MR. WARD:
Are-you saying'that you think the 9
methods of PRA and the safety goal =are not really going to 10 be practical tools in the future to make these regulatory 11 judgments?
i-12 I mean, here you have almost a miniature case 13 study for the application of quantitative. criteria, and you 14 have chosen not to use it, and you are sort of describing it 15 as not a workable approach.
16 So what does that say about the general approach 17 for safety goals?
18 MR. DENTON:
If you look, for example, at the 19 IDCOR PRA results, we have received f rom the IDCOR a -half 20 dozen or so PRAs.
They show that in their view the 21 probability of core melt is somewhere between low times 10 22 to the minus 5 or high times 10 to the minus 5, right below 23 10 to the minus 4.
i 24 *
'(2)-
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We'll probabaly come out in the same ballpark.
2 If that's really the case and then you find areas where you 3
-might make improvements below 10 to the minus 4, I think, in 4
general, industry really thinks that the 10 to the minus 4 5
maybe is a threshold below which the staff should work 6
pretty hard.
7 We're proposing sort of a sliding scale, but even 8
with the sliding-scale and making improvements in plants in 9
that range, using the thousand dollars a man-rem, there's 10 very little change that you can justify.
11 So what that says is that, for plants in that 12 range, the types of goals that are being discussed is not a 13 particular force or function for change.
14 MR. WARD:
But you don't accept that answer?
15 What the analysis is telling you then is that something I'
16 doesn't need to be changed, or you're unsatisfied with the 17 analysis.
18 MR. DENTON:
At the moment, the Commission hasn't 19 fully adopted the safety goal practice.
I felt the 20 systems needed a good, hard look to see if they did need to 21 be changed on an individual basis.
22 But, to try to pursue a generic backfit, using 23 the plants already down low, and using the thousand dollars 24 per man-rem, there's not many changes you can make in any of I~3 l
\\
25 l the auxilliary feedwater systems.
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I think that would be the result of going through s
2 just the PRA area.
And I wasn't satisfied with that 3
outcome.
I wanted to look through.and see if the systems 4
really were that good or not.
5 They look at things and they reached the judgment 6
and a number of improvements were identified that:the 7
licensee agreed with.
8 So, in that particular plant, we are now 9
satisfied.
10 VOICE:
Could I also add that the licensee did 11 reliability analysis and, based on his reliability analysis, 12 he made some changes to the plant.
In addition to the stuff 13 that we identified.
14 MR. WARD:
Reliability analysis of that sort, you.
15 aren't requiring that of the other six plants, I guess, are 16 you?
17 MR. DENTON:
No.
A number of them will have it, s.
18 but we've not required it because even requiring it requires 19 a showing that it's worthwhile.
And they're not 20 inexpensive, so it gets right back to the safety goal.
21 It is very important where the goal is.
If it's 22 defined one way, it says very few changes are needed in 23 present plants.
If it's defined another way, it says 24 perhaps major changes may be justified.
'"i 1
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1-agreed on the safety goal.- It's a very key area.
s_
2-MR. EBERSOLE:
I. don't know if you remember how:
p 3
often?these aux feed systems must fire up cnd do their thing 4
-on.these plants.
How of ten they have to do their thing.
5 How many times a~ year?
6 MR. DENTON:
I've gone-through that.
I don't-l 7
remember at the moment.
It does vary considerably, but some 8
plants are called on-quite often.-
9' MR. EBERSOLE:
Yes.
10 MR. DENTON:
You know, we're struggling with a 11-number of generic issues-trying to close those issues.
And 12-on a generic basis, using the-reduction of risk and using-
~
- - (
13 all the way through to outside health effects, and'using the-L 14 thousand dollars a man-rem, as Dave said, some people may 15 think that's not the right thing, what we should be doing.
16 But, at the mcment, that's'the way we've elected i
17 to do it.
And it doesn't result in very many changes from 18 plants who are below the 10 to the minus 4 core melt 19 probability, to start with.
And to get.down to the 10 to b
20 the minus 5 level, certainly there are very few changes that 21 the agency could justify in a plant with that low a core 22 melt probability, assuming the containment is reasonably 23 immune to early failures.
24 MR. WARD:
But your strategy now with these 4
l 25 plants is really by persuasion by involving yourself with I
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the licensee's people and pulling-out things that could be 2
. improved,.and so forth.
3 You're going to persuade them to make 4
improvements in these particular systems.
5 MR. DENTON:
I may not want to persuade them.
I-6 think it's more -- maybe my energy' level is winding down or 7
something with the new job coming up, but take AWS.
You.
8 know, trying to do something on a generic basis and making 9
it fit the differing plant designs and the differing systems 10 and configurations that are out.there is an enormously L
11 time-consuming job all the while the public is aware of the 12 risk there is from that possibility.
E13 I felt, after getting into this auxilliary
.14 feedwater system issue that there were enough differences-15 between the challenge rates and the maintenance and the 16 training and so forth, that we really should do it on a 17 plant-specific basis.
l 18 And if I find a plant and it's acceptable, then I 19 can work on that.
We're not going to try to promulgate some i
l 20 universal auxilliary feedwater reliability and showing that 21 that is requiered for all plants, when their probability of 22,
core melt varies differently anyway.
23 So, if we were the French regulators and all the 24 plants were basically the same, I might have gone a I
25 different way here.
But we've dealt with this collection of i
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plants with different vendors, different architect-engineers 2
-and on the advice of the staff, we elected to just go plant 3
by plant.
4 And I would suggest-that what I would like for 5
you to consider is don't prejudge it.
Let us give you a few 6
more reports and see how we've:come out.
If that hasn't met 7
the mark, well, we can do something else.
8 DR. REMICK:
Any other questions on this issue?
9 (No response.)
10 DR. REMICK:
Harold, did you have others?
11 MR. DENTON:
These are the only ones that we 12 specifically identified, but I'd be happy to address any 13 other --
14 DR. REMICK:
Are there other topics you'd like to 15 raise with Harold?
16 (No response.)
17 DR. OKRENT:
I'd like to just make one comment.
18 You mentioned that IDCOR was coming out with numbers, 10 to 19 the minus 5, and something times 10 to the minus 5.
There's 20 a family of PRAs or quasi-PRAs, a considerable number that 21 are relatively recent, where the numbers are several times 22 10 to the minus 4.
l 23 We've seen Conn Yankee, Turkey Point, a lot of 24 those done in connection with A-45.
The conclusion is that
(
25 just the decay heat removal is several times 10 to the minus ACE-FEDERAL REPORTERS, INC.
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4.
2 So I think one needs at least some caution ~when-3 one discusses the subject in making sure, 'for -whatever 4
reason, there appears to be.
5 MR. DENTON:
I think 1150 is going to show 6
numbers below 10 to the minus 4 also in the plants.that they 7
inspected.
Certainly for plants that get above 10 to the 8
minus 4.
Then the system is much more in a stronger forcing 9
function, to force directions in systems.
10 But I'm just making a general observation, if 11 it's below 10 to the minus 4, it's not a strong forcing 12 function for change.
If it's above 10 to the minus 4, it's 13 stronger.
14 DR. OKRENT:
I agree.
And I think that's one 15 place where the proposed matrix, or the cost benefit 16 approach that the Commission is proposing is not in harmony
.17 with the majority wish of the U.S. people.
18 MR. DENTON:
I think you're meeting with Vic this 19 afternoon.
20 DR. REMICK:
On safety goals?
We're meeting this 21 afternoon with staff on safety goals, that's correct.
And 22 Vic tomorrow on reorganization.
23 MR. DENTON:
I do think that whole system, the I
24 whole issue of safety goals and what should be put in the
("/T
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backfit or not, is as important a_ piece of strategic 2
planning as the Commission has underway.
3 DR. REMICK:
Any other questions or comments?
4 MR. MICHELSON:
Did we cover.this prioritization 5
of generic issues?-
6 DR. REMICK:
No, we did not.
Harold said he had 7
three.
Were you aware of that one as a possible topic?
8 Prioritization of generic issues?
9 MR. DENTON:
No, I wasn't.
Maybe we can talk 10 about it.
11 DR. REMICK:
The comment here is that the 12 concerns were expressed that the NRC staff's-system for p( >.
13 prioritization can sometimes leave an urgent item lie fallow 14 for a period of time, until it's prioritized.
15 Do you want to add to that?
16 MR. MICHELSON:
It wasn't my item.
I had a 17 related question on it.
18 DR. REMICK:
Why don't you raise the question?
l 19 MR. MICHELSON:
Whoever raised the issue ought to 20 of course make sure that the points are covered.
I was l
l 21 going to raise another issue.
l L
22 DR. REMICK:
I'm not sure who raised it.
Why I-L 23 don't you proceed?
l l
24 MR. MICHELSON:
One thing that concerns me a 25 little bit is the process of resolution of generic issues.
l 1
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It turns out a case in point being a 17 systems
'2 interaction.
This has been around a long time.
It's been 3
discussed a long time..
4 It was thought to be understood.
And now~we find-5 at-the point of resolution, the claim now is made:
Well, we 6
didn't really understand the problem.
And now that we do, 7
we'll make that a new generic issue.
But we will in.the 8
meantime resolve A-17, the portion we understand and want to 9
resolve now.
10 This bothers me a little bit because now people 11 say,-oh, A-17 has been resolved.
Well, A-17 really wasn' t 12 resolved at all by the resolution.
They would simply agree O
\\./
13 that there would be a new generic _ issue that would really 14 tackle the problem.
15 So I wanted to get your thoughts on when is the 16 generic issue finally resolved?
And how?
What do we do?
17 Do we hold up A-17?
Or do we just do it a piece at a time?
18 How should these be approached?
19 When we finally understand the problem and 20 finally realize what needs to be the definition of the 21 unresolved issue or the generic issue?
i 22 l MR. DENTON:
I think part of integrating the l
23 USI's and making sure you've got a relationship between one 24 and the other has been a problem for us.
Some of those seem 25 to lend themselves to resolution easier than others.
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I'd like to think that pressurized thermal shock, 2
even though it had many different disciplines involved in 3~
it -- transients, metallurgy, it did seem to. move along with 4
all the components coming in and they were resolved more or 5
less as an entity.
6' There's something about systems' interaction, and 7
it's hard to say what it is, we've never been quite able to i
8' grasp, I think, fully what the committee wants to do.
We've 9
talked about it back and forth for years and years.
10 I proposed one' time a solution for. systems 11 interaction would be to send Jessie to every power plant for 12 a month, and maybe that would be the best generic r't) 13 resolution.
14 But we had trouble identifying a pathway to 15 success.
16 MR. MICHELSON:
I think it's now understood 17 finally what the problem really is.
And now that it's 18 undernstood, now that we understand it, it will become a new 19 generic issue.
20 In the meantime, A-17 was resolved.
21 MR. DENTON:
I guess I wasn't aware that it had 22.
taken that turn.
I 23 l MR. MICHELSON:
I believe that's essentially i
24 where we're at.
O 25 MR. HERNAN:
That's part of it, Karl.
The other ACE-FEDERAL REPORTERS, INC.
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part is that we are providing guidance.
We're doing two 2
things in terms of the industry.
3 We are providing a letter that tells what we've 4
. discovered in our study of this issue.
5 MR. MICHELSON:
The difficulty is we have 6
narrowed the issue down to the part we easily understand, 7
and we're implementing it.
-Yet, we're claiming the issue is 8
resolved when the broader aspects of the issue, the ones 9
which really should have been addressed all along, are'now 10 finally understood and they're going to be identified as a 11 separate issue.
12 MR. HERNAN:
That's a common problem.
O
(_J-13 VOICE:
Even the PTS issue that Harold says is 14 resolved -- and I won't challenge him on that -- but 15 questions have been brought up about what happened.
And 16 that was excluded from PTS.
17 We have to circumscribe these issues in some way 18 and say, hey, for a purely administrative purpose, I at l'
19 least did that part of it.
And there are other generic 20 l issues, but that's just a matter of administrative control 21 of.giving the things a number and somebody taking 22 responsibility for resolving it.
I 23 !
MR. MICHELSON:
I guess it's a matter of 24 everybody that's involved understanding that system i
25 interaction really isn't solved, even though it's now been l
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resolved, that the solution will have to await this new 2
generic issue and its resolution.
3 If that's all understood every time you say 4
" systems interaction", then that's fine.
But people don't
-5 really communicate that way.
They say, oh, systems 6
interaction has been resolved.
7 MR. DENTON:
I think some things will never be 8
completely resolved.
Let's take water hammer.
We'll never 9
eliminate water hammer.
Until we define and access that 10 kind of thing, there will probably continue to be systems 11 interaction.
12 So you have to bite off a piece that you know how w
x-)
13 to solve.
I guess it would be like operator training.
If 14 we had called that a USI, I don't know whether we'd call it 15 resolved or not.
We've done a lot, and I'm sure we'll 16 continue to do more.
17 I'll look into that one, Karl.
18 MR. MICHELSON:
I've been trapped in the past 19 when I said, okay, we all understand.
We didn't really 20 resolve the problem, we just made a new one.
And then I got 21 l trapped later and then they said, oh, we thought that was 22 all taken care of.
And it wasn't all taken care of.
23 DR. SHEWMON:
Okay, you've made the point.
t 24 DR. REMICK:
Harold, we thank you for coming down
[)
i 25 again and joining us and sharing your views.
We understand l
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you'reftaking over the office of Governmental and Public 2
Affairs.
We want to wish you well in that.
3 We hope in that new function, you will come back 4
and talk to us again.
5 MR. DENTON:
Thank you.
It won't occur for 6
probably a couple more months, when we-settle down.
But I 7
will look forward to having the ACRS participate in the 8
meetnig with state and local officials.
9 (Laughter.)
10 MR. DENTON:
With Congressional involvement and 4
11 national involvement.
12 DR. SIESS:
We'll write them a letter.
13 DR. REMICK:
A concise letter.
'14 Thank you once again.
I suggest we adjourn and 15 reconvene at 2 p.m.
for Safety Goals.
16 (whereupon, at 12: 50 p.m., the meeting recessed, 17 to reconvene at 2:00 p.m.,
this same day.)
18 19 20 21 i
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AFTERNOON SESSION 2
.(2:00 p.m.)
13 DR. KERR:
(presiding)
We will begin our 4~
afternoon session, with thanks to Dr.'Remick for. chairing 5
the morning session.
6 We have a chance to do the implementation of the 7
NRC safety goal policy, and I will turn things over to 8
Mr. Okrent.
9 DR. OKRENT:
Thank you,-Mr. Chairman.
10 According to the original agenda, we had an hour.
11 and a half for this, and I will assume that is what we still 12 have.
m k_)
13 I am not going to give a long subcommittee report i
14 to try to discuss issues, and so forth, now.
I do want only 15 to make the observation that this is an important topic.
16 We heard Mr. Denton earlier today say, in fact, 17 it is a very important topic as part of strategic planning, 18 if you want to look at it that way.
19 I believe that even if we weren' t asked to 20 comment within the next two months -,this is what, January 21
-- by March -- we ought to try to have comments on the draft 22 of a final memorandum that the Staff has prepared, a final 23 interim memorandum that the Staff has prepared.
l 24 And so what I urge is that you start to think O
25 seriously about the matter in this hour and a half.
It i
i l
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will be for some a rehash of what we did in the subcommittee 2
yesterday, but for others, parts of it at least are 3'
'substantially different from.the things we talked about:
1 4
before.
l 5
My proposal is that next month we have a draf t 6
talking letter, where we try to get at the main points and 7.
see what the committee opinion is on this and then shoot for 8
a letter in March after we think we know-what the committee 9
opinion is.
10 And I suggested to Savio that we ask for four 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> rather than the two that I think I had mentioned to 12 Ray earlier.
- O 13 So with that introduction, let me note that I 14 have advised the Staff that we recommend that we.give them a 15 chance to go through this presentation.
I think we said 16 uninterrupted, didn't we, so they can get their story out 17 peaceably, and ask that-they emphasize particularly what I c
18 have called the matrix and the rules of thumb, and so l
[
19 forth, where I think some of the heart of the matter is.
l I
(
20 And then that would leave a reasonable time for 21 questions, roughly an hour.
i I
L 22 So unless the subcommittee members want to make 23 any special points before the Staff is up or other members, l
24 I would suggest we hear from Matt Taylor.
(
25 MR. TAYLOR:
This is Matt Taylor, from the NRC i
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Regional Operations and Generic Requirements Staff.
2 What I would like to do over the next-hour is to 3
give you a recap of the implementation framework we have put 4
together, the beginning of implementation of the safety 5
goal.
i 6
I do want to emphasize that we are'certainly not 7
hard and fast on the number of areas.
We are interested in 8
moving forward.
9 I would also add one other thought.
We briefed-10 the Commission this morning on this implementation 11 framework.
They did express an interest in actively hearing 12 the ACRS views on this matter.
O)
(-
13 I believe I told the subcommittee yesterday that 14 we would be happy with some feedback by the EEO, which the 15 Commission has requested also from the advisory committee.
16 With that, I will move in to the presentation.
17 (Slide.)
18 As I pointed out, what I have to say is basically 19 what we presented to the Commission this morning.
20 (S l ide. )
i 21 The presentation -- what I would like to do is 22 l briefly recap some of the major features of the policy I
23 !
statement.
I would like to discuss the interim framework 24 that we put together for beginning the safety goal O
25 implementation and some of the guidelines that we set forth i
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for moving. forward with more detailed implementation gui'elines in certain. areas ~of the regulatory program.
- 2 d
3 (Slide.)
'4 On August 4th, the Commission published in the 5
' Federal Register its policy statement.
I believe you 6
-gentlemen have seen these qualitative goals that-were 7
contained in the policy statement a number of times.. We 8
have discussed this over the past two. years.
9-The first safety goal is that individual members 10
,of the public should be provided a level of protection from 11 the consequences of nuclear power plant operations.such that-12 individuals bear no significant additional risk to life and 13 health.
f:
14 The second safety goal, societal risk to life and 15 health from nuclear power plant operations, should be 16 comparable to or less than the risks of generating 17 electricity by viable competing technologies and should not 18 be a significant addition to other societal risks.
19 (Slide.)
20 In the policy statement, the Commission 21 established two quantitative bases or guidelines to help us
~
22 determine whether or not the intent of the policy statement 23 had been achivved.
24 These were with respect to mortality risks, from O'-.
i 25 prompt fatality, the risk to an average individual in the l
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vicinity of a nuclear power plant.
Prompt fatalities that 2
might result from reactor accidents should not exceed 3
one-tenth of one percent of the sum of prompt fatality risk 4
results from other accidents to which members of the 5
U.S. population are generally exposed.
6 The risk to the population, second to the latent 7
cancer fatality objective as the risk to the population near 8
a nuclear power plant of cancer fatalities that might result 9
from nuclear power plant operations, should not exceed I
10 one-tenth of one percent of the sum of cancer fatality risks 11 resulting from all other causes.
12 (Slide.)
f-)s
(-
13 In its policy statement, the Commission commented 14 on the need for Staff to develop additional guidelines for 15
. regulatory implementation.
They pointed out several 16 guidelines that were needed.
17 These concerned plant performance guidelines with 18 respect to core melt, guidelines for cost / benefit analysis, 19 and we should address indicators of operation performance.
20 This is sort of a separate program.
The 21 indicators of operational performance is a separate program 22 at this point in time, which the Commission has recently 23 l approved for the Staff to undertake.
24 l The Commission also pointed out that they would 25 like to review and approve these guidelines.
The guidance ACE-FEDERAL REPORTERS, INC.
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to be developed would be based on a proposed general 2
performance guideline, which is to be further evaluated by 3
the Staff.
4 This guideline that was offered by the Commission 5
is as follows:
6 Consistent with the traditional defense in depth 7
approach and the accident mitigation philosophy requiring 8
reliable performance of containment systems, the overall 9
mean frequency of a large release of radioactive materials 10 to the environment from a reactor accident should be less 11 than one in 1 million per year of reactor operation.
12 I have added that we have tried to craft our 13 implementation strategy around this particular guideline 14 that the Commission offered.
15 I would also note that this is quite similar to 16 a guideline that the advisory committee itself proposed back 17 in April of 1986.
I believe that is the correct date, 18 April.
19 (Slide.)
l 20 With respect to our current status, we have 21 developed an interim quantitative and integrated 22 interpretation of the safety goal policy, including the 23 general performance guideline, to provide a framework for 24 the development of specific Staff guidance over various O
25 areas, program areas and decision areas, within NRC's ACE-FEDERAL REPORTERS, INC.
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. regulatory programs.
2 A specific guidance that is to evolve from.this 3
framework will be presented'to the Commission-for its 4
. approval prior to adoption 1as. final Staff guidance.
5 I would like to just point out we met with the 6
ACRS subcommittee and briefed them on the status of this 7
work on December 10th of last year. and again yesterday, and 8
today we are meeting with you.
9 I pointed out yesterday at the subcommittee we 10 would like the ACRS views and support in favor of moving.
11 forward with the' implementation framework.
12 (Slide.)
13 In looking at how the safety goal might be 14 implemented in the NRC. regulatory safety decision process, 15 we had to look across a number of program areas, and we had 16 to determine what are our available resources.
We do 17-recognize that NUREG-1150 is an important work.
We could 18 use this as a starting point to develop further tools to i
19 help us make safety goal comparisons.
20 This work in NUREG-1150 represents rebaselined 21 PRA studies that are in existence, and it is reflective of I
22 the state of the art as we know it today, as many attributes 23 will include the effects of the new source term.
They will 24 show the effects of safety goal comparisons, and it also
\\#
25 includes a substantial treatment of uncertainty.
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We also recognize the need to have some tools for 2
the Staff to assist in making quantitative estimates of the.
.3 effects of said decisions.
We.have those well under 4-development at this point in time.
These are what is called 5
here the SARA and the IRRAS program.
6 The systems analysis and risk assessment program 7
is basically a software program that is suitable for the PC 8
XT.
It enables -- or will enable the Staff to look at the 9
effect of a certain generic requirement and look across the 10 handful of plants and to gauge what might be the 11 significance in terms of core melt and what might be the 12 significance in terms of overall risk.
(G./
13 The IRRAS program basically is a tool that is 14 system level and would enable the Staff to do some hands-on 15 analysis of the reliability of systems.
Basically, it is a 16 fault tree tool.
17 DR. SilEWMON:
Are these something you will put on i
18 for technical assistance projects to get developed or have 19 at hand?
20 MR. TAYLOR:
I might add now that we already have 21 the framework of SARA on the XT in our office.
I am advised 22 '
that these have been updated to include four of the Plan 6 23 plants that are in NUREG-ll50, and I might add this is the 24 front-end core melt portion of the data and this is in-house 25 right now.
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So the framework is developed.
It'is a matter of 2
data and data validation and bringing on board the 3
additional NUREG-1150 plants and other PRAs, get the data 4
_into the PRA, peer review, and so forth.
5 So these are tools that should enable the Staff to do some hands-on estimation.
We also -- in developing 6
i 7
the framework for safety goal implementation, we recognize 8
we must have a feedback loop from the data that might appear.
9 on the horizon in terms of component failures, system level 10 failures, and adverse operating experience.
We need to have 11 that feedback loop.
12 We intend to take a closer look at both the
/~~.
-(_)
13 health effects and the economic effects that we see from 14 Chernobyl to make sure that we have those adequately 15 covered.
16 We don't see at this point in time major changes 17 being needed, but we will reconfirm that.
18 In terms of the package that you have before you 19 and the one that we provided to the Commission on January 20 2nd, we have offered once again an integrated safety goal 21 matrix to be used as sort of a template to gauge the Staff's 22 proposed requirements.
l 23 We have offered some general implementation 24 guidance -- that is certainly not the end-all and be-all O~/
25 that the Staff may have -- to mold this in a way that fits ACE-FEDERAL REPORTERS, INC.
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certain decision areas.
Some may be more quantitative.
2 Some may be less quantitative.
3 We have offered some plant performance guidelines 4
with respect'to core melt frequency for existing plants and 5
future plants.
6 We have also proposed a conceptual approach, the 7
large release' definition.
We plan to take a look at what 8
might be other definitions that would be suitable for 7
9 defining large release.
10 (S lide. )
11 With regard to where we see we might find some 12 benefit from the use of the safety goal comparisons in our b
V 13 decision process, we looked across a number of program 14 areas, and we saw that there are a number of generic issues, 15 numbering in excess of a hundred, I believe, at this point 16 in time.
17 Perhaps the NRR staff can make that more 18 specific, can give a more specific number.
19 But we saw that comparisons of the safety goals 20 l might benefit the decision process in terms of the I
21 !
resolution of generic issues.
22 We also saw that certainly our generic insights 23 that might be acquired through carrying out a severe 24 accident policy as well as plant specific items that the O
25 Staff might have to make decisions on and in terms of ACE-FEDERAL REPORTERS, INC.
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changes related to the source term changes, we see the 1150 s
2 work and safety goals potentially important factors in the 3
decision process here.
4 I would like to emphasize throughout all of these 5
safety goal comparisons and implementation of safety goals 6
this will remain but one factor in the decision process.
We 7
have that intent.
8 I don't mean to imply at all that sound 9
engineering judgment is going to be tossed out the window.
10 That is certainly not the effect.
11 Covering some of the other areas, as I have said, 12 there are plant specific requirements that might come about,
. -s-)
13 depending on the results of carrying out the severe accident 14 policy.
One might find some outliers that you could benefit 15 by taking a test of the significance against safety goals.
16 We see safety goals -- this is more PRA-oriented, 17 but in assessing regulatory priorities, perhaps research 18 priorities, or priorities in terms of the generic issue, we 19 see safety goals as potentially being useful in assessing 20 the significance of operational events.
We feel as though 4
21 the integrating tools we had can be ultimately made useful 22 for that purpose.
23 We also note that although this may be a moot 24 point at this point in time, that there are about 30 final 25 environmental statements that we have set forth to the ACE-FEDERAL REPORTERS, INC.
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public that contain a fairly extensive treatment of severe 2
accident risk, and it seems logical to perhaps include how 3
safety goals might be related to these severe accident risks 4
in the final environmental statements.
It may be a moot 5
point.
6 In terms of implementing procedures, over these 7
various decision areas, implementation areas, we would see 8
most areas to be completed in about one year.
That is our 9
present schedule.
Obviously, that is an overall schedule.
10 I believe the package you have in front of you 11 lays forth some of the projections that we have as of a 12 month ago.
13 We would plan to periodically brief'the advisory 14 committee and of course the Commission itself, and we would 15 solicit Commission review and approval before we adopted the 16 final implementation procedures in these areas.
17 Now, I will cover quickly this next viewgraph.
18 Ilow does this all fit together?
19 (Slide.)
i 20 l That is intended to show generally how it fits 21 together.
22 l We see the safety goal policy as being a logical 23 umbrella to be brought to bear over these various 24 implementation areas, and as I have pointed out, I have O)
(_
25 listed a number of the attributes that I have observed in ACE-FEDERAL REPORTERS, INC.
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the NUREG-1150 update, including the new source term 2
technology and_ WASH-1400 certainly with respect to the 3
common cause models, attention to the human operating 4
procedures that are operating today in France.
5 This essentially captures, as is seen by the 6'
Staff, it captures much of the improvements that may have 7
gone on subsequent to TMI, including the resolution of 8
generic.ssues and reupdates, if yc will, the'PRAs to 9
capture some of the improvements and some of the upgrading 10 procedures, or what have you, that have taken place since 11 TMI.
e 12 This-is a useful snapshot on the risk as well as 13 the state of the art modeling that we have today, and I see 14 this as a useful resource to begin the implenentation.
15 16 17 i,
l 18 19 20 '
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We would expect to feed much of this data into sa 2
the SARA and IRRAS integra ting tools.
I would add _that by 3
no means does this preclude the introduction of additional 4
PRAs.
5 I think the major limit is machine capacity.
As 6
I point out in the paper you have before you, you do have 7
some specific guidelines that would be folded into 8
developing the implementation procedures over these areas.
9 (Slide.)
10 This next viewgraph highlights some of the 11 principal ground rules.
There are others in the paper.
12
_These are the principal ones that we believe are consistent 13 with the instructions in the Commission's policy.
14 Safety goals will be used in conjunction with 15 traditional review methods.
That will be one factor and not 16 the sole factor, or not the dominant factor, or one 17 authoritative factor that is brought to bear.
18 We recognize, when I say sound plant management 19 remains an issue, we recognize that there is human 20 complacency, if you will.
Lack of attention to maintenance, 21 performance of the operators at the plant, and so forth, 22 that still remains a variable in this process.
That one has 23 to keep their eye on.
24 And I see the initiative tha t is one way of O
25 addressing this issue.
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In use of the safety goals, we need to recognize 2
that there are considerable uncertainties around our 3
quantitative projections.
And we need to recognize or 4
characterize these.
And we believe 1150 has done a fairly l
5 extensive job to this end.
l l
6 If we are to introduce additional PRAs into this l
l 7
framework, we would want to assure that they are peer-8 reviewed, that they're acceptably okay from the standpoint l
9 of the NRR staff, research staff, NRC staff, you gentlemen.
10 We intend to use both internal and external event 11 initiators as was specified by the Commissioners' policy 12 statement.
And also we would not intend to use these for 13 evaluations of security or sabotage issues.
14 We will use the safety goals as an important 15 authoritative factor in arriving at regulatory decisions, 16 ctor in arriving at regulatory decisions, 17 On the other hand, it must be clearly recognized 18 that the licensees must still meet regulations.
Safety 19 goals are not an excuse for escaping regulatory t
20 requirements.
21 The implementation strategy we put together in 22 this framework is expected to address existing and future 23 plants and the resolution of outstanding generic safety 24 issues.
O 25 DR. SHEWMON:
Will you tell us later today how ACE-FEDERAL REPORTERS, INC.
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you will take external events in?
Or is that' decided yet?
2' MR. TAYLOR:
I would note that NUREG 1150 -- let 3
me go back to figure one here.- NUREG 1150-in its present 4
form does not have external events included.
There is an 5
effort at followon that is planned to update the NUREG 1150 6
plants for this purpose.
7 What we do know is we have'other PRAs that are 8
available where you account for the treatment of external 4
9 events in one form or another.
We'll perhaps have to take ' a 10 look to see if we cannot use those as perhaps surrogates.
11 Now, I would add one other thought also.
In i
12 looking across the outstanding generic issu ss, one does not n
ss 13 find this as a particular inference because most of those do 14 not address external events.
15 I'm talking the numerous generic safety issues 16 that are prioritized.
And, for example, 0933, I can't give 17 you a fraction of those.
Perhaps someone in the audience 18 can.
19 But I think it's a fair characterization tha t 20 most of those do not relate to external events.
21 DR. SHEWMON:
He says tha t the external events 22 are unimportant because the USI is going to address them.
23 DR. OKRENT:
Or it could mean that the staf f 24 is--what's the word -- myopic.
.O 25 DR. KERR:
Please continue.
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(Slide.)
m 2
MR. TAYLOR:
In considering the Commission's 3
guidance for implementation, they did offer the general 4
performance guidelines and also helped us draft the 5
framework on implementing safety goals.
6 Some of the thoughts we had as we were going down
~7 this path were that, gee, this should apply to existing and 8
future. plants.
And we proposed that framework that we set 9
on the table here.
It should be consonant with the 10 Commission's policy on mortality risk, meaning tha t it 11 should not be too wide of the mortality risk by orders o,f 12 magni tude.
\\-)
13 It should capture accident uncertainties, and it 14 should.certainly capture the risk dominant releases.
And it 15 should, of course, include.Chernobyl.
But Chernobyl 16 undoubtedly was a large release, even though it had ef fects 17 that might be somewhat dif ferent than for U.S. plants.
18 It should also capture the early containment 19 failure possibilities and the possibilities of bypass.
In 20 other words, other release paths might exist.
I 21 We have settled on one definition and this is 22 being studied in the context of NUREG 1150.
This does not 23 rule out others.
And this would be the subject of further 24 consideration.
g-25 We have settled on one at least to take a look at ACE-FEDERAL REPORTERS, INC.
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and this is the complementary cumulative distribution 2
function that I believe most of you have seen as part of 3
most of the PRAs that I'm aware of.
And also this 4
complementary cumulative distribution function, which has 5
been displayed already in about 30 final environmental 6
statements.
7 What we would propose to do is constrain the 8
ordinance at less than or equal to 10 to the minus 6 9
frequence for one early fatality.
This is applied to all 10 distances and all affected populations beyond the site 11 boundary.
.12 As I pointed out, NUREG-1150 will display the 13 effect of this CCDF approach and our present insights are 14 that this will indeed be one of the more limiting 15 definitions if this definition is followed.
16 We would see this as being useful or capable of 17 being used as a surrogate to assure high confidence that we t
18 have achieved the Commission's mortality risk goals.
19 The quantitative 0.1 increment.
As I pointed 20 out, we will txa considering whether alternative approaches 21 have merit and what these might be.
22 (Slide.)
23 The next viewgraph is sort of a cartoon on what 24 this concept is.
It's not much that's really new.
What we O
25 would propose to do would be to put a limit lin@ or a tap on l.
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the CCDF curves as shown in the figure.
In effect, this 2
would constrain -- let me point out the CCDF.
The area 3
under this curve does represent the mean value.
And this 4
would be applied to all sites and all populations.
5 So it would ' constrain the release magnitudes for 6
all sites.
This does capture the intermediate-release 7
magnitudes.
It might be of high frequency.
It captures the 8
very large releases with their associated frequency.
9 It would capture the lower frequency at very high 10 releases, so it would capture the entire spectrum of 11 releases as we best can define those through probabalistic 12 risk assessment.
n
(_)
13 As I pointed out, this is a traditional display 14 that's used in PRA and Lit is not much new; the basic data 15 that goes into this display is that data that you would use 16 to massage a little bit. further to calculate the individual-17 risk objectives.
18 DR. MOELLER:
What was EF?
19 MR. TAYLOR:
I'm sorry.
What we have done is --
20 EF means early fatalities.
Now, as I said, this CCDF is 21 nothing but a traditional display of the probability versus 22 the outcome, or the probability of exceeding a certain 23 outcome.
24 This would be property damage, thyroid nodules, O
25 whatever your risk outcome of interest might be.
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case,'we are interested in-the mortality risk increment that 2
i's set forth in the Commission's policy statement.
As we 3
see it at'this point in time, our PRAs' do indicate that the 4
early fatality risk would be the controlling risk.
~5 DR. - KERR:- Are you going to talk later on about 6
how this dif fers from the early fatality guideline?
7 MR. TAYLOR:
In terms of magnitude?
How much 8
more restrictive it might be?
9 DR. KERR:
I would assume that it'is.different.
10 MR. TAYLOR:
It is different.
i 11 DR. KERR:
It sounds to me as if-it isn't 12 different the way you are presenting it.
13 MR. TAYLOR:
It's somewhat more restrictive than 14 the
.1.
15 DR. KERR:
But it's the same sort of guideline.
16 MR. TAYLOR:
It's the same sort of a guideline.
17 DR. KERR:
So-you are saying that the safety goal 18 is not good enough, you need a more restrictive guideline?
l 19 MR. TAYLOR:
I'm just saying we don' t need to L
20-necessarily go to that further calculational step.
And if 21 we meet or achieve this kind of definition, we have 22 adequately accounted for what we see as the uncertainties in 23 approaching or engaging the achievement of the 0.1 percent.
24 DR. KERR:
It just doesn't sound like a large O
25 release criterion to me.
It sounds like another version of ACE-FEDERAL REPORTERS, INC.
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4 2
MR.' TAYLOR:
It is not 'a dose itself.
-I t is not.
3
'a: risk level' dose.
It's a mortality risk.
- 4 DR. KERR:. I thought I was missing-something.
5 DR.~ SHEWMON:
It would have meant that if there 6
was an early fatality off site, it probably would be a 7
pretty large release eventually.'
8 MR. TAYLOR:
That's correct.
9' DR. KERR:
You might admit it.
I might not.
10
-You're perhaps more logical than I am.
11 MR. TAYLOR:
I think I've already made those 12 bottom points.
It is intended toLeapture the results of all 13 the severe core damage core melt accident release 14 mag nitudes, frequencies, pathways.
And it doesn' t - really 15 take into account passive features that might.be there to do
'16 mitigation.
'17 It takes into account the nature of the 18 containment response.
And it takes into account the 19 possibility of bypass.
20 DR. KERR:
But, in principle, it could be 21 satisfied in principle with no containment at all.
-22 MR. TAYLOR:
I do not read the Commission's 23 guidance that way.
-24 DR. KERR:
I don ' t ei'ther.
But what-I'm saying O
25 is what you're proposing, I think, could.
Couldn't it?
I ACE-FEDERAL REPORTERS, INC.
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-. don't see why it couldn't.
2-MR.LTAYLOR:
I. guess it does not' say that Thou 3
'Sh' alt Have A Containment.
It does not, no.
It does not say 4
that.-
5 But the guideline 'that we're operating under says 6
' consistent with traditional defense indepth.- -
[
7 DR. KERR:
I rec 6gnize that.
j-8 MR. TAYLOR:
This is more constraining.. A chancel 9
of the first mortality risk independent of distance, j
10 independent of location.
11 (Slide.)
12 Now, again, we are back with what we'have s
[
13.
discussed with you in the past, the integrated safety goal 14 matrix.
There's not an awful l'ot that's new -in there except -
15 the large release we have introduced.
The frequency of 16 large release.
The approach that's in the integrated safety:
I 17-goal matrix encourages as we presently see it, encourages 18 accident prevention.
19 But the degree to which it encourages accident-20 prevention depends on the achievement of the health effects i.
!~
p 21 as specified by the Commission policy.
l 22 This includes a sliding scale where the-safety 5
23 goals are achieved for averted on site costs as a benefit of 24 a cost benefit equation.
- O-25 Where the safety goals are not achieved, either 26 31 ACE-FEDERAL REPORTERS, INC.
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one of them, that would be the earlier, prompt fatality.
2 That would be the most controlling, as we said.
We would 3
propose to use 100 percent of the averted on site cost as an 4
incentive to achieve the safety goal, or safety 5
improvements.
It would achieve the safety goal.
6 Now, this use of 100 percent of averted on site 7
costs is of course biased towards preventing the accident 8
and preventing the core melt.
Where we have very high 9
frequencies either observed or revealed through operating 10 experience, the issue of a cost benefit approach included is 11 fixed at no cost or fixed at old costs, I should say.
12 I would note that in terms of the person-rem
(_]/
/
13 valuation, we would propose to use a thousand dollar per 14 person-rem as a surrogate to cover the societal health 15 ef fects of f site, which provides a surrogate and coverage of 16 property damage costs.
17 It does vary somewhat with the population density 18 at the site.
High population densities, the thousand 19 dollar per person-rem does lead forward in its conservatism 20 considerably with respect to covering the property damage 21 both on site and off site.
22 We also would propose to include the on site 23 occupational health effects that might be incurred as a 24 result of averting the accident or as a result of requiring f~)-
l
\\'
l 25 safety improvements.
To that end, they would both be valued l
l l
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at a thousand dollars per person-rem..
2 I would also note that in NUREG 1150 that there 3
is rather extensive discussion and display of various cost 4
benefit algorithms, with and without the averted on site 5
costs included.
6 (Slide.)-
7 I have to apologize.
I think you'll have to look 8
pre tty :losely at your handout.
That's not really legible.
9 I believe you gentlemen have seen before with, I would say, 10 not great enthusiasm, this rather complicated pictorial.
11 We are still proposing to go forward with this as 12 a template.
We believe this is useful in focusing the (m
\\-
13 issue.
We're proposing to resolve a generic issue.
14 If you're proposing to resolve a generic issue in 15 one way or another, the argument is that you' re either
-16 operating on accident prevention, you're trying to reduce 17 the frequency of a large release, you're trying to achieve 18 the Commission safety goals and you should have, I would 19 point out these three have to do with safety, and this last 20 column really relates to what might be judged as the 21 commensurate costs for achieving that safety.
22 Again, note that even when the Commission's 23 safety goals are achieved, there are still some justifiable 24 improvements that might be made at justifiable costs, if it l')
25 shows a safety improvement.
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With respect to the top of the chart, I'd like to 2
encourage future plants to do better in terms of the core 3
melt frequency.
4 DR. KERR:
What is going to be the definition of 5
"large-scale core melt"?
6 MR. TAYLOR:
Large-scale core melt in this case 7
is one that is not arrested prior to penetrating the reactor 8
vessel.
9 Why we've stuck with this large-scale core melt 10 frequency is -- and I'll give you my version of it.
There 11 are different viewpoints on how you can define this, I 12 guess.
13 My viewpoint is that the PRA has an inability 14 once the core starts to degrade, it really doesn't have a 15 good capability of predicting if you can arrest it before it 16 penetrates the reactor vessel.
17 1.8 19 20 l
21 22 l
23 24 n -
25 L
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As the studies seem to indicate right now, you do 2
increase the threat to containment integrity once you 3
penetrate that reactor vessel.
That is not to say that you 4
don't have threats without penetrating the reactor vessel.
5 You do.
6 But such issues as the way the containment or the 7
reactor pressure vessel is penetrated, direct heating, the 8
threat that might come f rom that phenomenon are quite 9
important in terms of possible early challenge to the 10 containment integrity, and if we do not penetrate the 11 reactor vessel and the rest of the core, then the challenge 12 to containment integrity is somewhat reduced.
13 And of course we are concerned in terms of the 14 mortality risk objectives.
Those are more serious 15 accidents, but proceed to that point and challenge 16 containment integrity and present life threatening forces.
17 DR. SHEWMON:
You feel that you do have a good 18 handle and do have good models and can do a reliable 19 calculation on the probability scenario between having a 20 core which doesn' t meet Appendix K any more, for example, 21 2200 F on the cladding, and when it starts going through the 22 pressure vessel?
23 MR. TAYLOR:
No.
My point is once we start 24 losing the core geometry --
f s
')
25 i CR. SHEWMON:
A minute ago you said when it goes ACE-FEDERAL REPORTERS, INC.
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1 through - the vessel.
2 MR. TAYLOR:
I said 1that 'is when it presents the 3
greatest-threat to containment. integrity.
I said:PRA has.an 4
inability to discriminate, but>once you start degradation of 5
the core, loss of geometry, will you arrest that or will you 6
not b'efore. it goes through' the vessel?
7 DR. SHEWMON:
So the answer to Professor-Kerr's.
1 l
8 question was as a large release you will take ' getting the
'9 cladding above 2200 F?
10 MR. TAYLOR:
No.
Maybe I misread the question.
11 He asked me what.large scale core melt frequency. meant, and j
12 I said that means, in my language, in my view, penetration.
~
'13 of the reactor vessel.
j, 14-DR. SHEWMON:
Fine' That is what I heard, too.
15 My.next question was:
do you feel you can handle l
16 the scenarios between damaged, melted cladding and going 17 through the vessel well enough that you can indeed -- you 18 said af ter it coes through the vessel you aren' t sure you l
l 19 can handle it.
I am not sure you can handle it before it
[
20 gets to the vessel.
Perhaps I misread my comments.
My 22 comment was probabilistic risk assessment cannot-f-
I.
23 discriminate between when the core starts to degrade and go l
24 into a melt state and the point where it might be arrested fs r
25 within the vessel or go through the vessel.
That was my l
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1 DAVbur 1
major point.
2 Once you go through the vessel, there is a 3
greater challenge threat to the containment integrity, and 4
it is that challenge threat that brings about the greatest 5
concern to the Commission's safety goals.
6 DR. SHEWMON:
Are you clear, Professor Kerr, how 7
he' is going to calculate when he has a large release because 8
to me it is extremely unclear what happens and what is done 9
by whom after he has got overheated cladding.
10 DR. KERR:
I think that is a rather large 11 release.
So I don't think he answered the question about a 12 large release.
13 I asked him what he meant by a large scale core 14 melt.
I think I know what he means by a large scale core 15 melt.
16 DR. SHEWMON:
That is going through the cladding, 17 going through the vessel.
18 DR. KERR:
That is core on the floor, to put it 19 briefly.
20 DR. SHEWMON:
So I am hung up on whether or not 21 he can calculate that with any certainty.
22 DR. KERR:
That was not the question I asked 23 him.
24 DR. SHEWMON:
Okay, let me take as a substitute 25 for this core melt, or how we get data out of the PRAs or i
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whether we substitute for 2200 K in the cladding is still 2
unclear, or did you answer that and I missed it?
3 MR. TAYLOR:
No.
I said once you go beyond that 4
point you cannot discriminate.
The PRA cannot do that at 5
this point in time, not well.
It is attempting to try to do 6
that with certain scenarios in 1150.
That is my 7
understanding.
8 DR. SHEWMON:
It sounds like once you have dried 9
out your core you are going to say that is equivalent to a 10 one in a million or a one in 10 to the 5th?
11 MR. TAYLOR:
No, that is equivalent to a large 12 scale core melt in our definition.
13 DR. SHEWMON:
That is a large amount of 14 conservatism.
15 MR. TAYLOR:
It depends on the particular 16 sequence, I would guess, yes.
17 DR. OKRENT:
There is a hand up.
18 MR. MARTIN:
This is Jim Martin, from Research.
19 Let me put an "if" at the beginning here.
The 20 "if" is very important with regard to how PRA can handle 21 this.
22 If there were in existence operating procedures 23 which the operators would use once a core starts to melt and 24 it were written down in the procedures tha t this, that or l
a 25 the other thing would turn that around and get cooling ACE-FEDERAL REPORTERS, INC.
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back, if that were.part of the plant procedures, then that 2
could be taken into account ~in the PRA, considering the 3
human factors, the efficacy.
4 Right now we don' t have those kinds of 5
procedures, and that is why, you know, you can assign then a 6
probability.
Well, once it starts will it go all the way to 7-the end?
8 DR. SHEWMON:
Did the people at TMI-2 have those 9
procedures that you would accept?
10 DR. KERP:
Mr. Shewmon, I think this is an 11 extremely important issue, but I-don't think it is one that 12 we are going to settle at this particular meeting, and I
?f.b x
13 would urge that we go ahead with Mr. Taylor's presentation.
14 DR. MOSLLER:
Excuse me.
Before you take the i.
15 chart down, I see what you are doing, and we have seen some 16 others before.
I 17 But what concerns me is whether we have met the l
18 health effects goals.
Prompt and latent will depend upon I
19 sheltering or evacuation or KI pills and even on the degree 20 of medical care.
21 Now, are you just factoring in an average case?
22 MR. TAYLOR:
The mean value, yes.
In other 23 words, would we go to an extreme case like heroic medical i
24 trea tment?
g-t
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sensitivity or the uncertainty.
2 DR. MOELLER:
Is it a northern plant or a 3
southern plant?
Do they have basements?
4 MR. TAYLOR:
I guess we are getting to the 5
consequence modeling itself.
6 DR. MOELLER:
All of that is important because 7
the health effects are your goal.
8 MR. TAYLOR:
That is correct.
Your individual 9
- risk,
.1 percent, would have to be assessed with those same 10 kinds of questions in mind.
11 DR. MOELLER:
Then what assumptions have gone 12 into this chart?
13 MR. TAYLOR:
I believe when I talked about the 14 large release, I would enter at first unity f atality with 15 the CCDP.
I would recognize the uncertainty around tha t 16 first fatality, and that uncertainty could come from a 17 number of things, including the assumptions of sheltering.
18 DR. KERR:
Let me try something.
I don't believe 19 you are answering his question.
Maybe I won' t ei ther.
20 But my impression -- tell me if I am wrong -- is 21 that the assumption is going to be made that if you are less 22 than 10 to the minus 5, you meet these other things anyway 23 because certain other PRAs have been done and they indicate
, - - x 24 that you won' t be in trouble.
t J
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there is some uncertainty.
So you have to go further.
I' 2-'
Is ' that sort of the spirit?
~
h 3
MR. TAYLOR:
That is' basically the approach we j
-1 take.
I 4
.5 Now, 10 to the minus 6 is tentative.
It includes 6
._some of the uncertainties in. consequence modeling,;the 7
accident projections, probabilistic estimates..
~
8 DR. KERR:
Is that what you are trying1 to get at?
9
'DR.'MOELLER:
Yes.
So enough PRAs-have been done
- 3 f-10
.to show.
11 DR. SIESS:
That is not consistent with PRAs 12 being plant specific, is it?
'13 MR. WARD:
Are those northern or southern PRAs?
14 MR. TAYLOR:
Both.
15 DR. KERR:
Go ahead.
i 16 MR. TAYLOR:
I believe Dr. Okrent said he~would
[
17-like us to spend some time on this particular viewgraph.
i; i
18 DR. OKRENT:
Well, we have already spent 20 19 minutes on history, which I asked you not to do, and I am 20 afraid if you spend too much more time there won't be any 21 time.for some probing questions.
22.
So I think, Matt, you had better present whatever 23 it is you are going to in the next five minutes.
24 MR. TAYLOR:
Fine.
I will jump over this.
L.
25 (Slide.)
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I won't dwell on this.
2 This is basically some illustrative examples of 3
what the range of justifiable costs for safety improvements, 4
safety improvement costs might be with use of the matrix as 5
a function of core melt, with or without the health effects a
6l being met.
7 I believe we have shown this relationship to the 8
committee in the past, and so I will not dwell on that.
I 9
think the important point is that for the average plant 10 there is not an awful lot of money available if one is 11 looking to use the overall money available to justify safety 12 improvements.
~~
13 The money does grow, however, with this 14 integrated matrix, with high core melt frequencies.
This 15 is largely dominated by the inclusion of onsite costs in the 16 equation.
17 DR. MOELLER:
What was the dif ference in the two 18 graphs -- tne black and the white?
19 MR. TAYLOR:
One would be with health effects 20 objectives would be met and one without.
The black would be 21 where they are not met.
22 In that case you would have a greater 23 con tribu tion from the averted onsite costs as a benefit 24 included in the cost / benefit equation.
.j l
25 '
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Did you have to assume some onsite ACE-FEDERAL REPORTERS, INC.
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costs for that?
2 MR. TAYLOR: - Yes, we did, and I can get into that j if you wish.
4 DR. SIESS:
Is it one number?
5 MR. TAYLOR:
We used basically what was set forth 6
in the April 1985 Steering Group report, about $3.7 7
billion.
8 (Slide.)
9 In your package we also have an example that we 10 would be exposing for use in the interim for trial use to 11 see how we might go about making the safety goal 12 comparisons.
O-13 DR. KERR:
What does trial use mean?
Trial use 14 on what?
15 MR. TAYLOR:
Trial use with respect to new 16 generic requirements, proposed generic changes.
17.
We completed this last month.
We would hope tha t 18 this might serve as a benchmark to help develop other 19 recommended procedures.
20 At present we are proposing, subject to serious 21 objections, one-year trial use of this.
We will put this 22 through revision.
We would begin -- basically, we would 23 seek Commission approval tf ter trial use for possible update 24 of the CRGR charter.
j-sg V
25 Basically, what we are proposing to do in this l
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procedure is to commence addressing the safety goals and the 2
regulatory impact analysis that is conducted on any proposed 3
generic requirement.
4 In the package you have Enclosure 2.
We have 5
offered some general rules of thumb based on our current 6
insights of uncertainty or what might constitute a 7
substantial increase in the overall protection of public 8
health and safety as measured by accident prevention or 9
accident mitigation.
10 In general, we have offered a rule of thumb that 11 a factor of 3, for example, improvement in the overall core 12 melt.
The Staf f might argue very successfully that there
'~'
13 is a very substantial increase in the overall protection.
14 We acknowledge in offering this rule of thumb the 15 uncertainty ranges.
Again, I would point out that the 16 uncertainty cuts two ways.
17 In trying to estimate where you might be in an 18 absolute sense when you state a risk, you have to contend 19 with uncertainty, but also in trying to improve the state of 20 risk you also have to account for the uncertainty.
21 DR. KERR:
When you talk about a factor of 3 risk 22 improvement --
23 MR. TAYLOR:
No, I am talking in terms of core 24 melt, such things as if we were to have one issue.
L,,
25 DR. KERR:
It was a factor of 3 when core melt ACE-FEDERAL REPORTERS, INC.
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was 10 to the minus 3, a factor of 3 when core melt was 10 2
to the minus 6?
3 MR. TAYLOR:
I wouldn' t think so.
I am talking 4
about a reasonable range, somewhat above 10 to the minus 4, 5
somewhere below 10 to the minus 4.
That is generally a 6
reasonable rule of thumb based on what we have seen thus 7
far.
8 That may be subject to some change.
But I see 9
factors of 2, 3, for example, between the mean, best 10 estimate mean and the upper 95 percent of the mean.
11 Also, in the procedure we are calling for 12 improvement in the cumulative accounting process.
f_s b
'13 I think we all recognize that our checkbook has 14-not been balanced perhaps with the best processes.
We do 15 have a lot of individual generic issues, some of which if 16 imposed in the wrong sequences end up fixing the same system 4
17 perhaps several times.
18 Perhaps that is not the cost effective way of 19 doing business.
We should then start keeping track of what 20 our projected risk reduction benefits are as well as costs i
21 of the proposals to improve safety and also for any 22 proposals that might be aimed at relaxing requirements.
23 We have offered a general rule of thumb for I
g3 24 relaxations, also.
The cumulative should not be more than I
(_)
1 25 10 percent.
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We would propose also to use the integrated 2
saf'etyngoal matrix in_ terms of the cost-and safety 3
. trade-of f s predicted ' there.
i 14 That basically recaps what I have.
+
5 DR. OKRENT:
What I would like to do now, if the 6
committee = will permit me, is to spend ~.about 10. or 12. minutes 7
just identifying what appear to me to be some of the issues 8
that you need to think about, and that should leave you 9
roughly 20 minutes for discussion with Mr. Taylor on 4
10 whatever you wish.
11 But I will use a few of his viewgraphs.
'Did.you 12 bring the viewgraph with the statement about' reasonable
-( ) -
13 assurance that you didn't use today, which you were asked to 14 bring?
f 15 MR. TAYLOR:
I thought you wanted to strip that l
1 16 out.
I have it.
l 17
'DR.
OKRENT:
Okay.
While he is bringing that 18 one, let me note a few things to think about.
19 The first is there is a considerable reference to 20 1150 as sort of a starting point, and I think you will find 21 1150 not only doesn' t treat external ef fects and certain l
22 internal effects, but that the reactors that have been I
2:3 examined in 1150 are not necessarily -- probably in my 24 opinion are not representative, at least with regard to core fg
.V 25 melt frequency of the family to which such estimates exist.
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.In that family the core melt estimates are much 2
larger.
That is again a personal opinion.
3' Again, a second thing of course is how far can 4
you go without including fire and seismic and some of these 5
other effects in' making decisions?
Should we press the 6
Commission to require the Staff to provide on an accelerated.
7 basis fire and seismic?
8 These were estimated at Indian Point and Zion.
9 That goes back to four or five years ago.
It was reviewed 10 by the laboratories 'for the NRC Staf f and either concurred 11 in or modified, and so forth.
12 So that is a second thing to think on.
O 13 14 15 16 17 18 1
l 19 l
20 l
21 22 l
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24 25 r
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(Slide.)
2 I want to call attention to this part of the 3
safety goal statement.
It's not our statement, but it's in 4
the safety goals, which says:
5 The Commission intends to continue to pursue a 6
regulatory program that has as its objective providing 7
reasonable assurance while giving appropriate consideration 8
to the uncertainties involved that a severe core damage 9
accident will not occur at a U.S.
nuclear power plant.
10 So I guess working backwards, that may be an 11 estimate of what does it mean to say:
12 I have a reasonable assurance that a severe core O
13 damage accident will not occur at a U.S.
nuclear power 14.
plant.
To whom we own the lifetime of the current family.
15 And after you've thought about that, you can 16 derive from this some mean core melt frequency which my 17 guess is is likely to be less than 10 to the minus 4.
18 That's my guess.
19 MR. WARD:
Less than or more than?
20 DR. OKRENT:
My guess is that you will want to 21 have reasonable assurance.
Not mean, but reasonable 22 assurance, I am making a guess.
And since some plants will 23 have extended life, and so forth.
Maybe I'm wrong.
That's 24 my guess.
Something less than 10 to the minus 4.
3 J
25 (Slide.)
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-1 But there's a need to have at least a ballpark.
2 number in mind in any event.- If one looks at this. row, this 3_
is.the core melt, 10 to the minus 3, 10 to the - minus. 4 4
mean. LIf I'm correct that you need less than 10 to the 5
minus 4, you pretty much have to remove any large family
~6
' from here unless they' re riding the upper limit, or they're 7
going to keep you from having this mean, because'one 10 to 8
the minus 5 and one 10 to the minus 3 do not add up to 10 to.
9 the minus 4.
10 So, in general, that particular hortatory 11 statement, or whatever it's called, it seems to me would 12 tend to push toward 10 to the minus 4.
And in effect, the 7_
13 ACRS had.a statement, you may-recall:
14 We think you should work toward 10 to the minus 4 15 using prudence with due regard to uncertainties.
16 DR. KERR:
It seems to me that that may be a good i
17 argument, or 10 to-the minus 4.
But that statement does not i
18 seem to be one of them.
I don't think it has any i
19
. quantitative significance.
r 20 DR. OKRENT:
It's there.
I'd pointing it out.
21 Look, I'm just saying these are some things --
22 DR. KERR:
I think you could make a better case 23 for 10 to the minus 4 than that.
24 DR. OKRENT:
I'm not trying to make a case, I'm 25 trying to point out this is in the safety policy statement, ACE-FEDERAL REPORTERS, INC.
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and this is supposed to be a matrix to implement it.
2 But the pressure in this row is not very great to 3
get this less than 10 to the minus 4.
So I just want to 4
note that.
5 Then, a second thing, which I think Kerr already 6
noted in a sense is that, when you get up to about 10 to the 7
minus 5 or less, it's not clear that there's much of a 8
requirement for containment performance in this set of 9
criteria.
And it's not clear that there's any pressure to 10 meet that part of the defense indepth concept.
11 So that independent of other aspects and keeping 12 in mind that according to Rowsome, uncertainties in risk are
^
13 I guess of the order of from "O on the one side to 200 on 14 the other side, or something like this.
Big, in other 15 words.
16 So that there is a problem as to whether this 17 particular matrix, even if you accept the sliding scale as 18 it's been provided, the idea, whether it provides the 19 incentives to achieve an appropriate defense indepth 20 regarding containment.
21 A third thing, I think, which is applicable, it 22 would be useful to take this matrix and see whether the 23 changes that the French and the Germans have implemented and 24 that the British have proposed in Sizewell would come
,~
O 25 anywhere close to being in the ballpark with this matrix.
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'If not, at least we ought to have a rationale of 2
why we mentioned that to the staf f. - But I think it's 3
something for the committee to think about.
m 4.
One other point, which is really not the fault of 5'
the matrix idea, I think was alluded ' to a little bit' in what -
6 Matt said.
7 That is, you can have accidents with large 8
releases.that don' t necessarily have very large health 9
effects but that affect national resources and are very.
I 10 expensive-in that' sense.
And that is just not in the 11
~ current safety policy, and it's something to think on.
12 And let me note just a couple of other' things.
It's not clear to me that this alternate criterion that Matt
-13.
[
-14 mentioned, if the likelihood of accidents killing one or I
15 more people is less than 10 to the minus 6_ per year, tha t -
r i
16 that's equivalent to the health effects.
l.
'17 It's much more conservative to the health ef fects l-18 criterion, and so forth.
Let me know what my question is 1
19 and I don't have an answer in.my own mind.
l l
20 But I do recall from WASH-1400 that the 21 likelihood of accidents which kill one or two people is not i-22 much different in early fatalities than the likelihood of i
23 accidents which kill a hundred to a thousand people.
24 That's a very flat curve.
And then it dips L:O l
25 down.
And so you could indeed have -- and now this gets I
p.
l l
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back to Kerr' d comment in not needing a containment.
2 You could have 50 accidents all out of frequency 3
of 10 to the minus 8th, each of which kills a thousand
[
4 people.
Ye t, it wouldn't exceed the criterion of a 5
probability of 10 to the minus 6 of killing one or more.
6 Now you say that's ridiculous, isn't it?
7 Well, I'm thinking of the Balsa Island site, 8
where the wind essentially always blows on shore and where 9
there was a huge population two miles from the reactor.
l 10 They didn't build that one, but it's not quite so impossible 11 to happen.
12 Anyway, that's one to think on.
O 13 DR. KERR:
Your time is up.
14 DR. OKRENT:
Okay, one more minute.
15 It seems to me you want to think very hard about 16 the rule of thumb of three.
Read about it, see what it 17 says, see how they propose to use i t, and see whether you 18 think that is something you want to endorse.
19 DR. SHEWMON:
Three what?
Rule of thumb is three 20 what?
21 DR. OKRENT:
I'll say what it is.
It was alluded 22 to.
I asked that he spell it out, but it wasn't in his 23 talk.
There's a statement somewhere in one of the handouts 24 you hava.
And we will not have read it in this meeting, but 25 by next month, I assume you'll know it by heart, if you can ACE-FEDERAL REPORTERS, INC.
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find it, which says that if some particular change won' t 2
affect the core melt frequency by at least a factor of 3, 3
it's probably not significant.
4 That's the rule of thumb of 3.
5 And what Bill asked was is it still the same 6
rule?
And it's the difference between 10 to the n.inus 3 and 7
3.3 times 10 to the minus 4, and 10 to the minus 5, and 3.3 8
times 10 to the minus 5.
9 DR. SHEWMON:
I've got it.
Thank you.
10 MR. TAYLOR:
May I read that?
11 DR. OKRENT:
Please.
12 MR. TAYLOR:
In 20 seconds.
i 13 DR. KERR:
Twenty seconds.
14 MR. TAYLOR:
That's on page 8, enclosure two.
It 15 gives the general rule of thumb.
The staff may elect to use 16 with little aryiment, little rebuttal offered, if the 17 improvement is a factn: of 3 or more, that constitutes a 18 substantial.
19 It's not a constraint.
It doesn' t say it must be 20 more than 3.
It says that is we'll accept that with little 21 argument.
22 DR. KERR:
Also, I think, in defense of 23 Mr. Rowsome, who is not here, my memory of what he said was 24 not that an uncertainty existed, but that he wouldn't be
-s 25 surprised if there was uncertainty.
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DR. OKRENT:
Sorry.
2 DR. SIESS:
He wouldn' t be surprised -- dif ferent 3
from saying with reasonable assurance?
4 DR. KERR:
Are there questions?
Mr. Moeller.
5 DR. MOELLER:
I still have a comment, or I 6
continue to beat the drum a little bit.
On page 3 of your 7
handout, the display viewgraph number three has the prompt 8
fatality risk and the latent cancer fatality risk for the 9
goal.
10 The drum I'm beating is that it would be 11 extremely helpful to everyone concerned if we had some 12 ballpark estimates of the doses that are associated with 7,
13 these go.1-.
14 The dose is related to the degree of medical 15 treatment and a few things like that.
Let me, I hope, 16 illustrate my point with this latent cancer fatality risk.
17 You could put an asterisk by that and a footnote 18 and say:
This is comparable to 40 CFR 190.
Now why do I 19 say that?
20 I say that realizing there are some nuances in 21 here that aren't quite straightforward.
But if you have a 22 person who receives 25 millirem a year for 70 years, they 23 get, you know, about one in three-quarter rem.
24 If you take a 10 to the minus 4 risk per rem, 25 that's 1.79 times 10 to the minus 4 risk of dying of a fatal ACE-FEDERAL REPORTERS, INC.
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cancer.
2 And if you then assume that 17.5 percent of our 3
population naturally dies of cancer, you're at your safety 4
goal at 25 millirem a year.
5 And I think it would be very helpful to begin to 6
have people understand this.
Now, it was either brilliance 7
on the part of the NRC staff that this latent cancer 8
fatality toll coincides with the EPA's 40 CPR 190.
9 MR. WARD:
Let's assume that.
10 (Laughter.)
11 MR. EBERSOLE:
What was going to be the other 12 word?
s
(
13 DR. KERR:
Next topic?
14 DR. MOELLER:
I would like to see doses done for 15 latent cancer like I've just done and doses done for prompt 16 fatalities, because releases don't mean much of anything if 17 I realize the goal is expressed in health effects.
18 MR. MARTIN:
Doses are produced by the codes and 19 the regulatory analysis as an intermediate step.
And in the 20 environmental reports that Matt was talking about, there are 21 doses displayed as a function of distance, and so on.
22 DR. KERR:
Mr. Moeller was not asking that 23 question.
24 MR. MARTIN:
I don' t see any problem with
(-
s.-
25 displaying this as part of a PRA.
I don't have any problem ACE-FEDERAL REPORTERS, INC.
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with.that.
But, when you get down to the bottom line, you 2
still have to go to the safety goal.
3 DR. KERR:
Did you have other questions, 4
Mr. Moeller?
5 DR. MOELLER:
You can take the safety goals which 6
are-way off over here and back up two or three steps and 7
give us laymen something to work with, that we could get our 8
hands on.
9 DR. FERR:
Next question?
Do you have further 10 questions?
11 DR. MOELLER:
No.
12 DR. KERR:
Next q'uestions?
f 13 MR. WARD:
Are we in the general category?
14 DR. KERR:
Yes, general, on this topic.
15
( Laugh ter. )
16 MR. WARD:
Matt, you've made the point that a 17 licensee or an applicant will not be able to point to 18 conformance with a safety goal as a reason for not 19 conforming with some other or with some particular 20 regulation.
21 MR. TAYLOR:
Excuse me.
22 MR. WARD:
That's not my question.
That's just 23 the beginning.
Is there going to be any explicit effort 24 within the staff to do something that the ACRS has asked in
(-]
s_/
25 a couple of letters?
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That is, to judge the body of regulations.
And I-2 guess, the body of regulatory practice against the safety 3
goal?
'4-MR. TAYLOR:
I believe this ef fort generally is 5
ongoing right now.
We have looked at some existing 6
requirements.
And there is a report.
I don't know how far 7
beyond that we can go.
8 MR. BURDICK:
This is Gary Burdick from the 9
Office of Research.
That program is being worked in a 10 division which I'm not in.
But it is starting out looking 11 at regulations which they think are pretty much a priori, 12 self-evident at this point in time, and not very risk-b 13 limitation-affected.
I 14 In the future, I think, yes, they will be going 15 to look at other regulations vis-a-vis the safety goals.
16 MR. WARD:
Where is that program?
Whose 17 responsible for it?
Does it have a name?
i 18 MR. BURDICK:
I believe it's called the risk 19 limitation effectiveness of regulations program.
That 20 program is i-Carrl Galler's division.
The branch chief, I 21 believe, is Jim Norberg.
22 The program manager is Tony Hsi.
23 MR. TAYLOR:
I might add risk significance of 24 regulations, regulatory guides.
I believe that's in your q\\ j 25 package.
We do envision bringing safety goals to bear on ACE-FEDERAL REPORTERS, INC.
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assessing the significance of regulation requirements.
2 MR. WARD:
Is there anything written?
3 VOICE:
There are several reports.
Do you want 4
me to have Tony Hsi send you all the reports?
5 MR. WARD:
Yes.
I'd like to see them.
6 DR. KERR:
Further questions?
7 (No response.)
8 DR. KERR:
I'm not sure.I know how to ask this 9
question, but let me ask it and see if it makes sense.
I'm 10 trying to see whether the safety goal and its implemer.ta tion 11 is meant to be used as what I call a primary standard in the 12 NBS sense of the word, or a secondary standard, or none of 13 the above.
14 I almos t ge t the impression from listening tha t 15 it's going to be applied on a plant by plant basis.
To me, 16 that's not a primary standard.
I had thought tha t the 17 safety goal would be something that I'd call sort of a 18 primary standard and that one would then craft regula tions,
19 procedures that would carry out the spirit of that, but 20 wouldn' t depend directly on it.
21 MR. TAYLOR:
I guess I would answer what I think 22 the question is.
We don't see any prohibition against using 23 this as a test of perhaps on a plant-specific basis, this is 24 not a licensing requirement.
But we could use that on a 7
~
25 l plant-specific basis in judging whether the forecast -- for ace-FEDERAL REPORTERS, INC.
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- ""E 2
DR. KERR:
I'm talking about the safety goals 3
here.
Not the implementation plan.
The safe ty goals.
4 5
6 7
8 9
10 11 12
(_./
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24 (v) i 25 l
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I am told, for example, and I haven't looked at 2
it in detail, that almost all the plants that have been 3
reviewed meet the safety goals.
4 MR. TAYLOR:
I think that is correct.
Most we 5
would expect to meet the
.l.
They would not necessarily 6
meet the 10 to the minus 6th definitions.
7 DR. KERR:
I have heard that.
So I am trying to 8
understand what the safety goals mean.
9 That seems to say you have got the safety goals, 10 almost everything, but we don' t really think that is good 11 enough.
So we are going to implement the safety goals by 12 making the plants better than the safety goals.
13 I may be oversimplifying, and maybe I 14 misunderstand.
15 DR. SIESS:
What do you mean by safety goals?
16 The health effects?
17 DR. KERR:
Yes.
18 DR. SIESS:
There's three other things in the 19 safety goals.
20 DR. KERR:
Those are guidelines.
I mean, 21 somebody tell me what the safety goals are then.
22 DR. SIESS:
The safety goals are the first two 23 qualitative statements.
Then there's two quantitative 24,
guidelines.
-s l
25 f DR. KERR:
That is right, which tell you?
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DR. SIESS:
There is the not in our lifetime 2
guideline and then there is 10 to the minus 6.
3 DR. KERR:
Where is the core melt guideline?
4 DR. SHEWMON:
10 to the minus 6.
5 DR. KERR:
Let me read you one.
6 DF
.ENT:
The not in our lifetime guideline is 7
the core melt. guideline.
8 DR. KERR:
This says the guidance will be based 9
on the following general performance guideline which is 10 proposed by the Commission for further Staf f examination.
11 I don't know what that means.
That is the 10 to 12 the minus 6.
13 I get the impression that the Staf f has examined 14 that and has accepted i t.
I was told it was being 15 implemented.
16 MR. TAYLOR:
What I am saying is that we have one 17 concept that is being examined as part of 1150 right now.
18 There is to be expected further work to look at whether or 19 not the risk of exposure could be crafted in another way 20 that would acceptably define safety goals or not or perhaps 21 looking more heavily into some definition of frequency and 22 dose.
to my or -(nal question, i
23 DR. KERR:
Getting back 24 is it the purpose of the implementation procedure to make s
v 25 plants better than the
.1 percent fatalities and the
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percent of the latent fatalities?
2 MR. TAYLOR:
I think I would answer it this way.
3 With recognition of the uncertainty and 4
recognition of the general performance guideline of 10 to 5
the minus 6, we are exploring what that means.
6 I have some illustration here of the fact that it 7
is more restrictive than the
.1, and it does account with a 8
fairly high confidence that you should achieve the safety 9
goals if you meet the 10 to the minus 6.
10 May I show those?
11 DR. KERR:
Sure.
12 (Slide.)
13 MR. TAYLOR:
Let's look at what we have so far in 14 the 1150 plants.
15 This is the individual risk of early fatality, 16 which is found on these plants to be the most controlling 17 risk.
Now, this is measured
.1 objectives in the safety 18 goal policy.
19 You can see there is fairly high confidence that 20 the safety goal is met.
21 !
DR. KERR:
Those are uncertainty bands?
22 MR. TAYLOR:
Those are uncertainty bands being 23 projected right now, 1150.
24,
(Slide.)
-)
25 Let's look at the CCDP limit line approach that ACE-FEDERAL REPORTERS, INC.
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we talked'about.
2 These same plants.
You see part of the 3
uncertainty band can extend above that.
4 DR. SIESS:
Didn't they say "mean"?
5 MR. TAYLOR:
That is right.
This is a range of 6
means here, based on sensitivity and so forth.
This is the 7
95 confidence on the mean, the predicted mean.
Calcula ted 8
mean, under this spectrum would be.-- and I am guessing at 9
this point in time -- probably a factor of 10 below that.
10 And I am guessing.
I may stand corrected.
11 DR. SHEWMON:
How would I recognize a CCDP if I 12 ever bumped into one?
13 MR. TAYLOR:
It is in almost every PRA.
I will 14 show you one.
15 DR. SHEWMON:
This is a probability of fatalities 16 or a probability of large releases?
17 DR. KERR:
Early fatalities.
18 DR. OKRENT:
It could be either.
19 MR. TAYLOR:
I apologize.
20 DR. OKRENT:
It is the cumulative probability 21 distribution.
22 DR. SIESS:
This is the one you were looking 23 for.
24 MR. TAYLOR:
Yes.
I just don' t have it.
I got V(~g 25 it in my briefcase there.
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DR. SIESS:
That is not the complete 2
distribution.
That is just above 1, right?
3 MR. TAYLOR:
That is correct, 1 or more.
4 DR. SIESS:
That is why it looks so funny.
5 MR. TAYLOR:
Obviously, you can calculate less 6
than 1.
7 DR. KERR:
Are there further questions?
8 (No response.)
9 DR. KERR:
How does the safety goal fit in to the 10 severe accident policy implementation, at least that part of 11 it that deals with independent plant examination?
12 Are these entirely separate, or are they to be 13 synchronized at some point?
14 MR. TAYLOR:
We are hoping these will be 15 synchronized.
There are implementation procedures.
16 DR. KERR:
I understand that in a regulatory 17 sense.
18
( Laugh ter. )
19 MR. TAYLOR:
We plan them to be synchronized.
20 DR. SHEWMON:
Do you feel that 1150 as it now 21 exists provides enough detail to go from the scenarios you 22 might postulate to the fatalities you need for this, or is 23 that a hope that it will evolve into something which will be 24 l the tool to do that?
25 MR. TAYLOR:
As a matter of fact, what I just ACE-FEDERAL REPORTERS, INC.
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showed here is nothing more than a display of the 2
uncertainties around that point on the CCDP.
3 DR. SHEWMON:
And this is from 1150 for some 4
scenario?
5 MR. TAYLOR:
Right.
6 DR. OKRENT:
Some plant.
7 MR. TAYLOR:
Right, some plants.
8 What this is basically -- and what you are 9
seeing -- the black lines are basically what is shown here 10 with respect to the CCDP.
It is the range of uncertainty 11 around that value.
~
12 DR. SHEWMON:
And that is for a group of 13 scenarios?
14 MR. TAYLOR:
That is all the scenarios that have 15 been identified, both core melt and the of f site risk.
16 DR. SHEWMON:
Sorry, your horizontal axis has 17 names on it, so I assume that all of those things except may 18 Zion --
19 MR. TAYLOR:
Zion, the results are not available 20 yet.
21 l This is the surry plant.
This is with the severe 22 l direct containment heating challenge which causes a very i
23 early failure of the containment.
This is without the 24 l direct containment heating.
This derives from when the 25 reactor pressure vessel is breached.
It is postulated tha t ACE-FEDERAL REPORTERS, INC.
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phenomenon causes direct containment heating and early 2
failure.
3 This is the Sequoyah plant.
4 This is the Peach Bottom plant.
5 This is the Grand Gulf plant.
6 These are the results that are available today 7
with 1150, and I understand the Zion results are in hand.
d They just haven' t been received to date, I don't think.
9 DR. KERR:
Paul, are you finished?
10 DR. SHEWMON:
Yes.
11 DR. KERR:
Mr. Siess?
12 DR. SIESS:
I want to change the subject
(
e 13 slightly.
14 How do you as a representative of the Staf f 15 interpret the not in our lifetime guideline?
16
( Laugh ter. )
17 DR. SIESS:
One interpretation Dr. Okrent 18 suggested is that reasonable assurance means maybe 95 1
19 percent confidence that it won' t happen in our lifetime, 50 20 years.
21 MR. TAYLOR:
I know the probability is -- I am 22 not trying to sound flippant -- between zero and 1, but zero 23 chance of core melt I don' t have a probability dif ferent 24 than that.
25 DR. SIESS:
You don't interpret -- Dr. Okrent ACE-FEDERAL REPORTERS, INC.
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was taking an approach that it would be-high confidence that 2
it wouldn't occur in the.next'50 years.
3 MR. TAYLOR:
I believe the word was " reasonable
.4 assurance."
5 DR. SIESS:
But you have to translate " reasonable
~
6 assurance" into something.
I assume it is a Poisson 7
process.
8 DR..OKRENT:
When I once asked Staf f what 9
reasonable assurance meant in the context of high level 10 waste, they said 90 to 95 percent confidence.
11 DR. SIESS:
I assume some sort _of a process will 12 take the curve set.
So I can find out what that curve set 13 has to be. for a 95 percent probability that it won' t happen 14 in the next 50 years.
15 MR. TAYLOR:
Yes.
One can make some estimates.
16 DR. SIESS:
Right now what are you doing?
Are 17 you doing anything?
18 MR. TAYLOR:
I am not trying to hook a frequency 19 to that.
I understand from the Commission's discussion this 20 morning they would be adding a frequency, giving us guidance i
21 on that, on what that means.
22 So I would not prejudge the Commission's 23 guidance.
24 DR. SIESS:
What I gathered you were saying was 25 that it is zero, and zero is unachievable.
Thetefore, you ACE-FEDERAL REPORTERS, INC.
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are taking -- there is something that you should work 2
toward?
3 MR. TAYLOR:
As I spelled out.
4 DR. SIESS:
That is reasonable achievable?
5 MR. TAYLOR:
I see reasonable assurances.
6 The intent to pursue a regulatory program such 7
that there is reasonable assurance of no severe core damage 8
accident.
9 I am paraphrasing, I believe.
10 DR. SIESS:
Those are the words.
I just don' t 11 know what they mean.
12 MR. TAYLOR:
I interpreted -- I believe page 20 m
13 of Enclosure 1.
I said that is the pursuit of a rigorous 14 regulatory program that will spot, detect, track any 15 encroachments.
It will head off the possibility of core 16 melt.
17 I don' t know how to chacacterize tha t in terms of L8 particular frequency.
They have specified zero.
That is 19 the only frequency I can hang my hat on.
20 DR. KERR:
I think you have done a good job of 21 i explaining that.
22 Thank you very much.
23 Mr. Rosztoczy.
(
24 MR. ROSZTOCZY:
Mr. Chairman, as part of the
, ~
,1 25 severe accident implementation program, we have done some ACE-FEDERAL REPORTERS, INC.
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090114 10 174 DAVbur 1-calculations which go in this direction that might be of 2
some help toithe committee.
3 Just as you stated, you.cannot start-from zero, 4
so you have to start with some assumed number.
The 5
Commission stated that they do not want to see an accident 6
.in this country.
7
~First, we limited it to 40 years, and they 8
assumed 125 reactors, which is a little bit ~ more than 9
presently-but not much.
So using the 40 years,.we asked the 10 question what does the Commission's statement mean that they 11 don' t want to see any?
12 We interpreted it that by not wanting - to see any O
13 means they want to see-something significantly less than 1, 14 in this big.1 order of magnitude less.
15 So we start with that one and work back from 16 that.
Then comes the question of the uncertainties.
17 Uncertaintywise, we make one assumption, that the 13 distribution is lognormal, and that is a relatively good l
19 assumption.
20 All the data which we have seen that goes into 21 the PRAs show it is closer to lognormal than any other I
22 distribution.
We assume lognormal distributions.
4 23 In addition to that, we assume 90 percent
(
24 probability; that is, reasonable assurance, and the mean and s
25 the 90 percent probability distance, how much they are i
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apart, is the measure of the uncertainty.
2 It turns out that that number can be bounded 3
somewhat.
Independent of exactly how the distributions 4
are, you can use that number to bound the uncertainties.
5 Then you put all of these together and you see 6
what core damage frequency should be met in order to meet 7
this overall s tatement, and you come up with something just 8
slightly less than 10 to the minus 5.
So 10 'to the minus 5 9
is a very good number.
10 This is one of the reasons why we are proposing 11 it.
12 DR. KERR:
I hope someone will explain to the 13 Commission that this is what they mean because they don't 14 know that that is what they meant.
15 MR. ROSZTOCZY:
The Commission asked just exactly 16 for that this morning.
17 DR. REMICK:
Did they accept that answer?
18 DR. KERR:
Gentlemen, the schedule calls for a 19 break.
We will start again at a quarter of.
20 (Whereupon, at 3:35 p.m., the committee was 21 recessed, to go into unrecorded session.)
22 23
(~
24
~.-
25 ACE-FEDERAL REPORTERS, INC.
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CERTIFICATE OF OFFICIAL REPORTER
.A v
This is to certify that the attached proceedings before-the UNITED STATES NUCLEAR REGULATORY COMMISSION in the matter of:
NAME OF PROCEEDING: ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 321TH GENERAL MEETING DOCKET NO.:
PLACE:
Washington, D. C.
DATE:
Thursday, Ja'nuary 8, 1987 were held as herein appears, and that this is the original transcript thereof for the file of the United States Nuclear Regulatory Commission.
(sigt)
(TYPED)
DAVID L.
HOFFMAN Official Reporter
~
fffbhfEk#
Reporter s O
CONTAINMENT SEVERE ACCIDENT CAPABILITY O
LEVELS OF DEFENSE DESIGN APPROACH e PREVENTION e REDUCE CORE DAMAGE PROB-ABILITY (<10-6/RY) e MITIGATION
- OVERPRESSURE
- NO EARLY FAILURES FOR DOMINANT SEQUENCES
- ACCOMMODATE 100% MWR HYDROGEN TO FACTORED LOADS
- THREE DIVISION HEAT REMOVAL
- HYDR 0 GEN BURNING
- INERT ATMOSPHERE
,O
- CORE DEBRIS ATTACK
- DRYWELL SPRAYS - TWO DIVISIONS e FAIL SAFE e RETAIN SUPPRESSION POOL AT ULTIMATE FAILURE e P0OL SCRUBBING e MAKE BYPASS UNLIKELY e PROVISION FOR VENT l
ADDITIONAL FILTER VENT SYSTEM NOT NECESSARY O
_ _.