ML20043G797
| ML20043G797 | |
| Person / Time | |
|---|---|
| Issue date: | 06/04/1990 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 9006210142 | |
| Download: ML20043G797 (85) | |
Text
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UNITED STATES OF AMERTCA i
NUCLEAR REGULATORY COMMIS SION e
A Tf(13l BRIEFING BY ALWR UTILITY STEERING COMMITTEE ON ADVANCED LIGHT WATER REACTOR CERTIFICATION ISSUES LOCatiODl ROCKVILLE, MARYLAND l
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Date-JUNE 4,'1990 l-Pag 6S; i
63 PAGES i
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NEALR.GROSSANDC0.,INC.
C00?f REPORTERS AND TRANSCRIBERS 1323 Rhode Island Avenue, Northwest Washington, D.C.
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oy DISCLAIMER This is an unoffi'cial transcript of a meeting of the United States Nuclear Regulatory Commission held on June 4. 1990.
in the Commission's office at One White Flint North, Rockville, Maryland.
Th6 meeting was open to public attendance and observation.
This transcript has not been reviewed, corrected or edited, and it may contain-inaccuracies.
The transcript is intended solely for general informational purposes.
As provided by 10 CFR 9.103, it is not part'of the formal or informal record of decision of the matters discussed.
Expressions of opinion in. this transcript do not necessarily reflect final determination or beliefs.
No pleading or other paper may be filed with the Commission in any proceeding as the result of, or addressed to, any statement or argument contained herein, except as-the Commission may authorize.
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>4 UNITED STATES OF AMERICA g
'J NUCLEAR REGULATORY COMMISSION j' f BRIEFING B,Y ALWR UTILITY STEERING COMMITTEE ON ADVANCED LIGHT WATER REACTOR CERTIFICATION ISSUES PUBLIC MEETING Nuclear Regulatory Commission One White Flint North Rockville, Maryland l.]
Monday, June 4, 1990 The. Commis sion. me t in open session, pursuant to notice, at 9:00 a.m.,
Kenneth M.
Carr',
. Chairman,' presiding.
\\
COMMISSIONERS PRESENT:
4-KENNETH'M. CARR, Chairman of the Commission KENNETH C.
ROGERS,_ Commissioner JAMES R.
CURTISS, Commissioner FORREST J. REMICK, Commissioner NEAL R. GROSS court RIPoRTIRS AND TRANSCRIBERS 1323 RHoDE 15 LAND AVINUE. H.W.
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t R9p STAFF AND PRESENTERS SEATED AT THE COMMISSION TABLE:
D SAMUEL J.
CHILK,. Secretary WILLIAM C.
PARLER, General Counsel E.E.
- KINTNER, C h a i r m a n',
ALWR Utility ' Steering
. Committee J.J. TAYLOR, EPRI W.R.
SUGNET, EPRI W.H. LAYMAN, EPRI i
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2 9:05 a.m.
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CHAIRMAN CARR:
Good morning, ladies and 4
gentlemen.
5 Commissioner Roberts will not be with us 6
today.
We expect Commissioner Rogers to join us 7
shortly.
8 The purpose of today's meeting is for the 9
ALWR Utility Steering Commit',ee to brief the 10 Commission on advancs?
light water reactor 11 certification issues.
This meetito was requested by 12 the' Steering Committee so that its views on the 15 13 certification issues currently before the Commission 14 could be presented.
15 The Commission was briefed on these issues 16 by. the NRC staff on May 3rd, 1990 and has received
'17 comments from the Advisory Committee on Reactor 18 Safeguards.,
19 I
understand that copies of the 20 presentation slides and the paper, SECY-90-016, 21 currently before the Commission, are available -' at the 22 entrance to the meeting room.
23 Do any of my fellow Commissioners have 24 opening remarks?
25 If not, who is proceeding first, Mr.
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. Taylor or Mr. Kintner?
"'li 2
MR '. KINTNER:
I guess I will.
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CHAIRMAN CARR:
Ed, go ahead.
4 MR.
KINTNER:
We really do appreciate 5
being able to talk to you on this subject this 6
morning.
7 I have with me today Byron Lee from 8
Pat Mcdonald, who I think you know, is a very 9
energetic member of our Steering Committee.
These 10 members will be speaking shortly and I thins you 11 probably already know them too.
12
.We appreciate the statements the 13-Commission'has made in the last few months regarding i
14 the function and the priority of the requirements 15 documents.
They've confirmed our belief that we're 16 dealing with many important, difficult, technical 17 issues we need to resolve to achieve a fresh look 18 towards the safer, better reactors for the-future.
19 We also want to thank the staff for the 20 many days of intense discussions which have taken 21 place in the last couple of weeks on these issues.
A 22 great deal of progress was made in exchanging and 23 understanding information which resolve the' issues and 24 we've made very significant progress which culminated
- )
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1 Thursday.
So, we'll report to you today on what's-2 happened in the meantime, as well as what was the 3
original reason for our request to get ~ together with 4
you.
5 Since we met on September 20th last,-
6 several things have happened which affect the ALWR 7
program positively.
The first is the Nuclear Power 8
Oversight Committee.
Senior utility industry 9
representatives adopted a resolution which, and here I.
10 quote, "specifically recognizes and endorses EPRI and 11 the Utility Steering Committee as representing the 12 nuclear utility industry to carry out the following 13 throughout the ALWR program: discuss and resolve with
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14 the NRC the priority of industry needs; discuss and 15 resolve with NRC _ issues of consistency between ~ ALWR 16 design requirements and NRC licensing requirements; 17 act as the nuclear utility's principal interface with 18 the NSS suppliers of ALWR plants."
That's-the. end of 19 the quotation.
Very strong endorsement of what we're 20 trying to do.
21 In the meantime, since September, the 22 Department of Energy has entered into two significant 23 contracts with GE and Westinghouse for the further j
24 development of the ALWR passive plant designs.
These
(,j 25 are, we believe, important considerations associated l
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1-with strengthening the effort we're embarked on.
2 When we met - with you in September was 3
- said, "We believe if there is to be a potential for 4
reinauguration in nuclear power plant construction, it 5
must be inspired by a fresh look at how nuclear plants
'6 are designed and built.
The advanced light water u
7 reactor program is an attempt to provide such a fresh 8
look."
-j 9
Now,-we requested this meeting because you
-l 10 had the two meetings, the last one the 3rd of May,
.11 which were briefings by the staff and which we 12 believed in many respects didn't fully appreciate what 13 we were proposing to do.
There are a number of 14 reasons for that, but I think we have now made so much i
15 progress in understanding each other there's no point i
16 in going into.those issues.
17 But there were really significant 18 differences, as we believe, between what we were 19' proposing to do in the requirements doc'ument and what 20 the staff understood we were proposing to do.
21 In the preparation of the requirements 22-documents, we worked towards a comprehensive and 23 cohesive approach to safety which we believe answers 24-some of the questions raised by several members of the
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25 ACRS about coherence.
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1 the definition of' coherence, but nevertheless it was 2
used and'we've tried to present in the requirements 3
document a cohesive, coherent view of safety and 4
reactor plants.
5 The value principles which we've used to 6
provide that coherence are simplicity and margin.
7 Simplicity because the very complexity of reactor 8
plants as they've evolved is a'significant part of the 9
difficulty of operating them safely.
10 This point has generally been agreed to by 11 those 'who are involved in the operations, the 12 utilities, the INPO and the NRC itself.
They are not 13 just words, they are significant safety matters and 14 they are not public relations ploys, as you might 15-conclude from the May 3rd briefing, they are honest to 16 God steps toward safety.. Simpler plants are easier to 17
- operate, easier to maintain and more forgiving of 18 human errors and maintenance staffs.
19 Similarly, increased margins, where it's 20 practical to do that, make future plants more reliable 21 a
safer.
This increases response times, decreases 22' temperatures and power densities, will further reduce 23 challenges to both equipment and personnel.
'24 We have in the requirements document
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25 emphasized these points throughout and not only in a NEAL' R. GROSS CoVRT REPORTERS AND TRANSCRIBER $
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reactor plant, 'but in the entire plant, the steam-2 plant, the electrical _ plant as well.
3 Now, these are new avenues toward safety.
4 They follow after years of development in which 5
competitive environment driving forces were far larger 6
and larger plants operating at higher. temperatures and 7
with smaller engineering margins.
Design and 8
regulation then required increased numbers of safety 9
components and systems.
It was inevitable.
The 10 results were greater challenges to the operators and 11 greater potential for equipment failure from the added
- 12 complexity and reduced margin.
-.s-.
13 We believe we're succeeding in moving 14 towards our goals of simplicity and margin and we have 15 in the requirements document established requirements 16 ' _
which go beyond those previously_ accepted or required 17 by the regulations.
We've been motivated to do that l
i 18 because we truly believe these are directions - towards 19 greater overall efficiency of operation.
They also 20 provide greater protection of investment, a goal which 21 has been vital to the utilities since THI-2.
This is 22 an important consideration which is very, very hard to 23 accept, that the utilities have a reason to design for 24 safety because they want to protect the investment.
_/
25 When one of these plants has an action like TMI-2, NEAL R. GROSS court REPORTERS AND TRANSCRIBERS 1323 RHoDI 15 LAND AVINUI. H.W.
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it 's obvious what that means and if an accident rc,
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2' doesn't happen in the first place, it protects - the 3
public just as well as if it happened and you had all 4
the other kinds of protective features.
5 We know no better way to improve 6
reliability and reduce potential for severe accidents 7
and we know of no better way to contribute to public 8
t,afety.
9 Further need for the utilities is, if 10 we're going to enter a new era of nuclear power 11 generation, is regulatory stability.
The Commission 12 has been pressed for years with pleas for further 13 stability in its processes.
Utilities simply cannot E
14 in the future risk the large investments a nuclear 15 plant requirements without greater assurance that that 16 investment can be p u t.. to practical use within a 17 reasonable time.
18 Therefore,.one of the reasons the 19 requirements documents impose requirements beyond 20
. existing regulation is to provide some additional 21 regulatory margin so that there. will be greater-22 assurance that plants designed and built to these-23 requirements could be licensed and operated without 24 long and 'cos tly delays.
We intended that the I
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mechanism-towards stabilization _through that means and 2
because this could be the framework'for the beginning t
3
'of' safety review.
If these matters are agreed to as a 4
ganeric matter in advance, then it ought to be easier 5-for the staff and everyone else to come to conclusions 6
about the matters affecting safety.
7 I would like to point out the requirements 8
documents are requirements, they are nct just targets.
9 It's intended that all reasonable steps will be-taken 10 to achieve' these requirements with or without 11 additional actions on -the part of the NRC staff.
12 These requirements are not a public relations ploy.
13 We do need to demonstrate to-the public that we're
{J"
.1 14 providing increased assurances of safety and we should 15 not apologize for that.
But we also'need to provide.
16 the~same assurance to the potential owners.
17-The sincerity with which the ALWR process 18 has worked towards those objectives seems, to some.
19;
- degree, to have been lost by the reviewers.
It's I
20-understandable that having experienced more than a 21 decade of opposite pressures, the staff would like to 22 take advantage of every opportunity to regulate the 23' higher standards wherever they seem to offer clear 24 advantages.
Doing that has negative aspects.
The h,,
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-resultL in deprociation of enthusiasm f elt-by the 2
utilities and their suppliers when their strong 3
effort's to provide additional safety and reliability 4
in fundamental ways are quickly absorbed in 5
regulation.
6 I would like to point out 'today we're 7
talking about severe accident issues, but this'is only 8
one side of the reactor safety considerations.
The 9
other is avoiding _ accidents-in the first place.
There 10 i's a balance <hich must be struck between these two.
11 That balance, we believe, was heavily in favor of 12 mitigating accidents once they occurred.
We've tried i
13 in requirements documents to strengthen the side that 14 looks at preventing the accidents in the first place.
.15 Then, after having done that, the maximum, practical-16 degree we have, in fact, also accepted the-requirement
- 17 that we must mitigate the consequences of anything 18 that should occur.
19 Another important factor of what we've 20' tried to do from the beginning of the EPRI effort was l.
21-to. assure that the great body of additional l
22 operational and research information ~ generated over 1
23 the last 20 years could be applied, revisiting many
.24 safety issues on a sounder technical basis than.was -
25 available when the regulations themselves were
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12 1-established.
Many considerations other than purelf 2
technical ~ determine regulat; on.
But a ti.'orough,
'3 dialectical process based on the best technical 4
information available is an important first-step in 5
moving towards the new generation of safer reactors.
6 The best practical technical understanding is needed 7
if designs and operating procedures are to lead to 8
improved safety and acceptance.
9 We had hoped that the requirements 10 documents and our discussions with the NRC staff would 11 elicit that -sort of
- open, thorough, technical 12 discussion.
To that end we submitted the safety 13 chapter for the ~ evolutionary plant requirements in b'
_ 14 late 1987 and we received a staff response in February 15 of 1990.
So, discussions since that time now have 16 begun, but we've simply not had time for a thorough 17 airing of these complex technical subjects and it may 18 be that such discussions not thought to be needed for 19 the evolutionary plant-because 'of the kinds _ of 20 chronology that's been involved in that certification 21 effort, but we believe that it is not too late to do a-22 thorough job of airing of the technical issues to the 23 maximum practical degree that either side can bring to
~
24 the table before we move on as required in the 4
.. s 25 requirements document.
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1 What: is decided now in these matters will d
2 very likely determine the course ci nuclear history 3-for a long time and a great deal is known that vasn't 1
4 known 20 years ago.
1 5
Now, we also.think there is no particular-6 need to rush to a conclusion on these matters even for i
7 the evolutionary plants, although we would not propose 8
to stand in the way of the certification process.
9 With that as a background, let-me now ask 1.
10 Bill Layman and Bill Sugnet of EPRI to talk to the:
11 individual process and technical issues which we 12 requested at this meeting to discuss with you.
13 MR. LAYMAN:
(Slide)
Gary Vine, could vs k
14-start with slide 3, please?
15 We don't believe that regulatory stability 16
'will be assured if generic issues resolution is on an l-17 application by application basis.
The requirements l.
18 document could supplant the case by case resolution l
s 19-for some of:the issues discussed in SECY-90-016.
l l.
20-The concept of parallel rulemaking l-i 21.
discussed on 5/3 appears unnecessary if'the ALWR DSER 22 is the acceptance basis and certification rule locks 23 in this resolution for the design.
Generic rulemaking 24 would cause a major delay in certification.
The r
./.
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areas as supported by-the technical basis.
2 (Slide)
Next slide, please.
~3 The Advanced Light Water Reactor ' Utility 4-Steering Committee has been working very closely with 5
the reactor suppliers and we want to emphasize that 6
the Committee does not want to stand in - the way of 7
evolutionary plant certification.
Although, as has B
been stated before in this case, we think the cart got j
9 before the horse in the certification versus the 10 requirements document.
11 The Committee does want to continue the 12 dialogue on open issues and we'd like to emphasize 13 that, as Ed mentioned, we believe there's time to have g
14 an open dialogue on issues and reach a technically 15 based stable resolution.
There are too many 16 expedients that have come back to bite us at a later 17 date.
18 (Slide)
Next slide, please.
19 COMMISSIONER REMICK:
Bill, could you just 20 be a little. bit more specific on that point?
I think, 21 Ed, you said there was no need to rush, but not
.22 interfere with certification.
Bill, you just said it 23 in a slightly different way.
Could you be just a 24 little bit more specific in what you mean?
25 MR. LAYMAf Yes.
We don't think that it w,,,..
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15
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1 will delay things in that there isn't somebody that l
{ " '
2 has a order in at this point in time.
We believe thr:
3 during this hiatus of nuclear construction,- it's the.
4 time to step back and to resolve some of these-5 technical issues that have been resolved by an 6
arbitrary fiat in the past where there had not been an 7
adequate technical basis established and there may 8
have been years of research and development that have 9
occurred since then that do give us the basis for a 10 relook at some of those particular points.
The source 11 term is an obvious issue in this area.
Also, the 12 hydrogen problem is another obvious issue in this 13 area.
14 COMMISSIONER REMICK:
Doesn't this mean 15 then on some issues though that if you're going to 16-proceed with certification, you're going ahead'on a case t
L 17 by case basis and selling some issues?
l 18 MR.
TAYLOR:
Forrest, we have accepted l-19 that.
The point is both the certification and the 1
20 requirements document evolution for the evolutionary i
21 plants have been carried out in parallel and it's not 22 practical to expect the series approach that otherwise
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23 would be ideal.
24 A reason for this from the viewpoint of 25 the U.S.
program is a
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1 standardization process. itself and that has some
.l b
j 2
urgency. in light of the complexity of-that l
l 3
demonstration.
l
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4 COMMISSIONER REMICK:
I understand what 5
you're seying.
6 MR. LAYMAN:
Could we have the next slide, l
7 please?
l l
8 The stability in the design process does l
t 9
aid in fostering investor confidence also.
The margin
)
10 helps to ensure stability in the design process, 11 Regulatory margin continues to be available for future 12 use.
It allows margin to deal with new technical.
l 13 issues in the certification review and to deal with
(.,
14 new issues after certification.
Margins should be 15
'available to subsequent designs for flexibility in 16 tceir certification - and to allow the designers the l
17 oppor? unity to improve on these initially-certified 18 plants.
f L
19 We believe that for reasons such.as these i
20 it's important that. the margin not be absorbed into l
21 regulation.
There are cases in SECY-90-016 where L
22 margin does get absorbed or is recommended to get-
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23 absorbed into regulation.
24 COMMISSIONER REMICK:
Could you be just J'
25 more specific there?
Which ones come to mind?
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1 MR. LAYMAN:
Let_me go to the next slide.
."7 2-COMMISSIONER REMICK:
Fine.
Okay.
3 MR.
LAYMAN:
There's one very good n
4 specific one there.
We have an example with station 5
blackout.
The ALWR requirements go very significantly 6
beyond the station blackout rule.
We.have required a s
7 large capacity alternate AC source.
This is a five to 8
ten megawatt combustion turbine.
This is one of our 9
requirements documents requirements which is above and 10 beyond that which is specified in the present station 11 blackout rule.90-016 does recommend putting that 12 into regulation, that that not be considered margin.
13 Now, we've done many.other things also to b
+
14 increase the margin over the station blackout rule.
15 We have an independent reserve transformer which is 16 independent from the switchyard.
The generator f
17 breaker has a load rejection capability, 100 percent l
18.
rejection capability in the case of the PWR and _40 i
19 percent in the case of the BWR.
The generator breaker 20-will stay shut on load rejection and furnish house 21 loads from the main generator, which gives us an l'
22 additional power source.
L l
23 We have six safety grade batteries on the 1
l:
[
24 PWR and eight safety grade batteries on the BWR.
l(;j -
25 There is a new concept that we've put in on the three l
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tier distribution system so that we have much more
~ '
2 reliability. for the important non-safety AC power 3
motors.
There's margin and the requirements have 4
provided capability that meet or exceed both the 5
alternate AC option and the coping option for the' 4
6 station blackout rule.
7 In addition to the combustion turbine, 8
which is required, we've required an eight hour coping 9
capability for loss of all off-site and on-site AC.
10 There are no non-safety loads on the safety buses ~.
11 We've required that.
We would hate to see things like 12 this absorbed' into the regulatory, so that the-13 designers of future plants then start with this as a 0?
14
-base line and then get ratcheted to a new level.
We 15 believe that some of these margins that we've 16 discussed here need to be preserved as margin so that~
17 there's a flexibility in-future designs.
18 COMMISSIONER CURTISS:
Your argument; here, 19 I take it, is that the existing regulatory base 20 established for the current plants ought to serve as 21 the point of departure that would in turn permit you 22 to add margin on top of what we require for the 23 existing plants.
24 MR. LAYMAN:
Definitely, yes.
I'd like to
(,.
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-19 1-process,.although it is'not in the regulation, the 2
certified plant has this margin specified; in the 7
3 certification.
So, it isn't something that the
+
4 operator can take away at a later date.
It's part of 5
that certifice.cion.
6 COMMISSIONER CURTISS:
I guess in a 7
broader sense, I take it what you're saying is that in 8
no respects as a regulatory matter should we as an 9
agency impose requirements that go beyond the existing 10 reactor. licensing basis?
i 11 MR. LAYMAN:
I wouldn't go that far.
12 COMMISSIONER CURTISS:
As you go through 13 the discussion, I guess I'd like you to give me
-g.
14 examples where you think that would be appropriate.
15 MR.
LAYMAN:
Well, I think ~ Bill Sugnet 16 will pick up on that, I believe, in talking about the 17 issues.
18 COMMISSIONER CURTISS:
Okay.
19-MR. LAYMAN:
I believe that we're at that-20 point now anyway.
21 So,
- Bill, would you address the next 22 viewgraphs?
23 MR. SUGNET:
(Slide)
Yes.
On the next i
24 two charts, I've listed the 15 issues addressed in
(_;, /
25 SECY-90-016 and I've broken them into two groups.
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20 1
first group is called potentially resolved issues
[D 2
because we thirk we are either at the point of
- s. -..
3.
resolution or co1 verging on a point of resolution in 4
our discussions with the NRC staff.
The second group 5
is unresolved and I'll speak to those individually.
6 But with respect'to the first group, the 7
first four items on this chart, we believe that we are 8
essentially resolved with the staff.
That is, we 9
think that they understand and accept the position 10 that we've expressed in the requirements document and 11 are ready to state that it resolves the issue.
12 On the last six items on the chart, while 13 we have made progress, particularly in the last two
(.~l
' ~_
-14 weeks in our discussions with the staff, there is 15 still some difference between our positions and there 16 are also cases
- where, as a
result of these 17 discussions, both our position and the staff's-18 position have changed.
l 19 For example, in the anticipated transient 20 without scram area, the ACRS commented that they would 1
21 prefer an approach of allowing.a plant to ride'through 22 an ATWS rather than requiring simply.a diverse scram 23 mechanism.
In the May 3rd Commission meeting, and in 24 our recent discussions with the staff, we think we are 4,_j 25 moving more in the direction of allowing either a NEAL R. GROSS COURT RIPoRTER$ AND TRANSCRIBER $
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1, diverse scram capability or a demonstrated capability 2
to ride this event out.
So, that's my understanding 6
3 of the direction where we're headed now, but I don't' 4
think that one.is completely closed yet.
5 COMMISSIONER REMICK:
Question.
You're 6
understanding I realize you can't speak for the 7
staff, but your understanding of staff positions on 8
these issues that you say are potentially resolved, 9
are these different than what the staff expressed in 10 90-016?
11 MR.
SUGNET:
We have three bases.
The 12 first is the draft safety evaluation report tha't the 13 staff has provided us on our requirements document,.
(,. ).,
14 and then the f urther - inf ormation that is required in 15 the SECY, augmented by our understanding of the 16 discussions that took place on May 3rd and the 17 discussions we've had with the staff over the last two 18 weeks.
So, that collective set of information forms 19 my information base on where I think the staff's 20 position is on these.
I agree with you, I'd certainly 21 hesitate-to speak for the staff.
I'm only giving you 22 our impression of where we think we are.
23 In a number of tl.e issues, we would like 24 to achieve an industry-wide resolution, as was y
25 mentioned earlier in the presentation.
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do that as early as practicable.
We would like not to 2
have to wait for application by application resolution 3
where it doesn't appear to be necessary.
4 An example of that from this first chart 5
is the OBE/SSE issue.
Both we and the staff have 6
expressed our view that the operating basis earthquake 7
should not be controlling for the plant design.
We've 8
put forward-a specific proposal on the magnitude of 9
the operating bacis earthquake and the rationale for 10 that magnitud..
We'd like to pursue that issue' to 11 closure with the staff on an industry-wide be. sis.
He 12
.think it can be.done and once done, then all of the 13 applications and plants can follow suit thereafter V 3y
"~
14 So, one of the themes that we'd like to 15 stress is generic resolution of issues across the 16 industry using our utility requirements document as a 17 vehicle for that.
18 COMMISSIONER. CURTISS :
Well, let me go 19 back to the earlier question I raised on the four that 20 you've described as resolved, the four at the top 21 there.
If I recall what the staff is proposing, at in fact, maybe on all four of them, 22 least on 23 they're proposing to go beyond the existing regulatory 24 requirements.
When you say they're resolved, is it 25 that they are resolved except for this question about j
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how you regulate margin?
2 MR.
SUGNET:
Yes.
Let me comment.
I 3
don't think we want to assume the position of telling 4
the Commission or the staff whether or not they should 5
make new regulatory requirements.
We think that's 6
your business and you're going ts have to make those 7
decisions.
We simply want to point out that if an 8
improvement that is volunteered by the industry as 9.
part of these requirements document is codified into 10 regulatory requirements, then it eliminates the 11 flexibility of the industry and the designers to 12 operate and to assure that they will be licensable at 13 any point in time.
That's a very valuable commodity
(=
s.
14 to us.
So, we would encourage that you not go further 15 than you think is absolutely necessary f or saf ety, that 16 you now jump to include additional features that we 17 have provided in the require'nents document simply 18 because they are there.
19-CHAIRMAN CARR:
When we certify that 20 design in a rule, that will become a requirement.
21 MR. SUGNET:
We understand. hat any design 22 certified'that includes those provisions is certified
'23 on that basis and that can never be taken away.
W.e 24 have no problem with that.
(,,,
25 CHAIRMAN CARR:
We want standardized HEAL R. GROSS court RIPoRTERS AND TRANSCRIBERS 1323 RHoDI 45 LAND AVENUE, N.W.
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designs.-
I don't want a lot of flexibility in the
[
2 designers.
3 MR. KINTNER:
That's the point.
Once this' 4
is certified, it is_then codified and for not just one 5
plant, but for that whole class of plants, all the i
6 sisters as well.
7 MR. TAYLOR:
It's our judgment that a real 8
contribution to standardization will occur if we-can 9
get generic resolution across plant designs as the 10 first step.
11 MR.
LAYMAN:
But there will have to be 12 future plants after this first certification.
13 COMMISSIONER CURTISS:
I'm still --
1,7. ;.
~
14 MR. LAYMAN:
Both designers will need some 15 flexibility to get-the model.
16 COMMISSIONER CURTISS:
I guess I'm still 27 grappling with what your benchmark is or your starting l
18 point for purposes of applying the rule - that w.e
'19 shouldn't regulate away the margin that you all 20 include, let's say, on station blackout, to take the 21 example that you've given.
22-Let me turn the argument around and ask 23 you, for some of' these issues that we have resolved 24 for existing plants, which I take it in the case of
,-(, '
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end point for the regulatory requirements with 2
everything else above that constituting your margin 3
for purposes of licensability.
4 But on that one, and perhaps on some of 5
these others, when we look at the requirements for the 6
existing plants, the evaluation that we go through, 7
including a cost benefit analysis, may actually take a 8
look at an issue'and decide what's feasible based upon 9
the fact that you've got an existing plant operating
-10 out there with concrete having been poured and options 11
-available to you that might be more constrained than 12 what you could do with the advanced reactors.
13 Wouldn't the. cost benefit balance if you
\\-
14 applied it for an advanced reactor be struck 15 differently in the case of some of these?
If that's if the case, is it appropriate to say that for the 17 resolutions achieved f or the _ existing plants, that 18 ought to be the end point for regulatory requirements
'19 and everything beyond that ought to be, let's say, 20 EPRI margin, if you will?
E 21 MR. SUGNET:
I think, as I said earlier, I
22 we would not presume to tell the Commission where to
\\--
l.
23 draw that line.
We think that's your business.
We h
24 simply want you to understand that it's valuable to us 1,
25 to have margin between what the minimum regulatory NEAL R. GROSS.
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26 1
requirements are and what the industry's requirements 2
of the-designer are so that we assure that we have a
(
3 wide white space between our design and the minimum' 4
regulatory requirements.
5 MR.
LAYMAN:
I think thgt we do know 6
historically how the margins have been absorbed.
7 COMMISSIONER CURTISS:
Right.
8 COMMISSIONER ROGERS:
Well, I don't know, 9
I'm having a little-trouble with this argument because 10 it seems to me that there's a question of whether 11 you're objecting to the margin or the mechanisms'for 12 achieving that margin.
I don't understand whether' 1
13 you're calling them the same or not.
I can understand a
L 14 locking into particular ways of establishing a margin 15 as a constraint on designers.
There may be some other 16 way to achieve that margin through some kind of 17 technical ingenuity, and I would be in favor of
'18 allowing that freedom, but it seems to me that safety-19 margins by themselves, if they are achievable ' and 20 generally achievable throughout the industry, can be 21 reached and are being reached, should then become 22 codified and expected by the regulatory agency.
23 I don't see t a regulatory agency can 24 maintain its credibility if it maintains its I,.,.
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farther and farther behind what the industry can, in 3
2 fact, achieve in safety.
3 MR.
TAYLOR:
The codification, 4
Commissioner, will occur in the certification process.
5 There's no que.stion that will be the case.
We're 6
suggesting that the approval of the requirements j
7 document, which will include this margin, not include 8
in that same sense a change in the regulations to, in
{
C effect, take the margin into regulation.
10 COMMISSIONER ROGERS:
Well, I don't know.
11 It seems to me what you're arguing for is codifying 12 the margins through the design certification process 13
- which, in fact then, is making specifi, ways of
(
[
14 achieving those margins codified.
I would just raise 15 the question whether it isn't fair for the regulatory 16 agency to consider those achievable at some point
)
17 without specifying exactly how those margins are to be 18 achieved.
I'm wondering whether you're really 19 addressing that question or not in your suggestion.
20 MR. KINTNER:
I think we are addressing 2
21 it.
This is, as you say, a question of mechanism more l
l 22 than anything else.
If you look at what has happened l
23 from the other side, ycu see that here is a case where i
24 in a number of steps we have taken actions which I l
! i.,,
25 think the staff would not on it own have been able to l
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I 28 I
carry cut.
2 One example is maximum temperature out of 3
the reactor vessel.
That was a retl battle with us 4
and the vendors.
The staff was, I think, prepared to B
accept temperatures much higher.
But now, that's in 6
this document.
It vill be codified when the plants 7
that are certified to this document are certified-and r
8 will become an equal mechanism for the regulator to 9
assure that the best safety practices are being 10 followed.
Obviously, we can't take the position that
~
11 we shouldn't be doing that.
12 But let me say also that, and you must 13 understand that this is a reasonable thing to have 14 occurred, when 1 *ese issues came up with us, many of 15 them were debated and debated intensively within the i
[
16 Steering Committee and with the vendors.
It was 17 argued to us that, "If you do that, it will quickly be 1S lost.
It's just going to be taken away."
So, that l
19 kind of interest in doing things which fundamentally 20 are correct from a safety point of view is deadened to 21 some degree if, in fact, you immediately lo.se it for r
22 an absolute fiat which then is extremely difficult to 23 change.
24 Now, what we've said is that what we hope
'l c..
25 would happen is that the requirements document, once l
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1
29 1
- adopted, once it has gone through the process of i(
2 resolving the issues with the staff and they have 3
issued us an SER which says, "This is licensable,"
4 that any deviation from it would have to be justified 5
on an ad hoc basis, which means that to some degree 6
the requirements document now is a part of the 7
regulatory process.
That allows the capability to do 8
additional work and additional design efforts without 9
the scnse that as soon as you do something good, it's 10 gone.
11 I go back to what I said previously, which 12 is the question of stabilization.
The industry is 13 just frightened of ratcheting, a
continually
(,
' ~ '
14 ratcheting process in the name of safety, which is 15 obviously hard to argue against.
But sooner or later i
16 it gets to the point where the design efforts and the 17 cons truction -ef f orts drag. out snd plants are not 18 feasible, they're just not feasible.
19 So, that's what's behind this.
As Bill 20 says, we can't possibly tell you you can't regulate to 21 the best safety considerations.
But the mechanism by 22 which you do that might be somewhat different.
23 COMMISSIONER CURTISS:
I find the argument
- t 14 more persuasive when it comes down to a question like 25 the 10- d versus 10-8 safety goal.
We talked about NEAL R. GROSS COURT REPORTER $ AND TRANSCRIBIR5 i
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...s
30 I
1 that at the last meeting and if the Commission should 2
decide to establish 10-4 as the target for both 3
existing and future plants, then it does seem to me 4
that it's imprudent. It takes away your margin f or us in E
the context of the EPRI requirements document to 6
regulate to 10- 8 7
The concern I guess I have and the 8
question that I'm raising is a narrower one and that 9
is take station blackout as an exa.ple.
Do you 1
10 propose, in that case or others, that the end poin*
t 11 for regulatory action be the existing set of 1
12 requirements for, say, station, blackout?
If you do, 13 how do you respond to the argument that those t
I 14 requirements were developed with the existing reactors i
i a
15 in mind and with the cost benefit considerations i
16 focused on existing as opposed to future reactors?
i 17 I'm not unsympathetic to the argument that 18 the ratcheting concern is one that we ought to be 19 careful to address.
I'm not sure at this point where i
20 you define the benchmark, but it's a question.
I 21 MR. TAYLOR:
It's not a simple answer, but l
I 22 that is a good example of what I was talking about.
23 We really wrestled with this question of how do you 24 provide insurance --
x 25 CHAIRMAN CARR:
- Well, I
think the NEAL R. GROSS COURT REPORTER $ AND TRAN$CRillR$
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31 j:
1 arguments boil down to is the next generation going to
(
2 be safer because we regulate it to require it to be 3
safer or is it going to be safer because you're going 4
to design it and build it to be safer?
We're not 5
going to solve that here, right now, but that's where 6
we're going.
7 In the interest of time, let's proceed.
6 MR. SUGl:ET:
(Slide)
On the next chart, 9
I've Idsted the issues not yet resolved.
The first 10 one, the safety goal issue, I think we and the staff 11 don't have any strong disagreements about the levels 12 of the various safety goals.
I think this does boil 13 down to the discussion of the margin between what the 14 designer works to as opposed to what the regulatory 15 requirement is.
I have a chart that describes that in 16 the handout, but I'm not going to speak to it further 17 in this presentation.
I think it's self-evident and I j
18 think we've talked enough about the margin question..
19 The other three are the hydrogen issue, l
20 the containment performance and vent issue, and the I
i l
21 source term.
I will speak to each of those I
1 22 individually in the following charts.
i-
23 (Slide)
With respect to the hydrogen 24
- issue, we have proposed that the deterministic I
25 evaluation case for hydrogen control should be based NEAL R. GROSS
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n
3g O
1 on 75 percent active fuel cladding oxidation as
['
2 opposed to the 100 percent active fuel cladding 3
oxidation that is in 10 CFR 50.34(f).
4 We have provided a technical report that 5
considers both the experimental data, the TMI data 6
- point, and a host of analyses and supports our 75 7
percent cladding oxidation as a reasonable upper limit 8
considering both hydrogen generated within the reactor 9
vessel during core overheat 1ng and after the reactor 10 vessel were to be failed.
11 One point that we'want to make, the ALWR 12 requirements relies on the strength and the volume of 13 the containment to deal with hydrogen.
In the case
- i..
14 that we have proposed, that is 75 percent active 15 reacted clad, when we perform our evaluation against 16 10 CFR 50. 34 (f ),
we would include the steam pressure t
17' from an accident coupled with the global burn of 75
('
18 percent hydrogen.
This would be a more demanding 19 evaluation case than an accident pressure with smaller i
20 incremental burns on top of that that are caused by a 21 control system.
1 22 So, we believe that the evaluation case 23 that we have proposed to deal with is a more 24 challenging one from the standpoint of containment
.,j 25 strength and capability.
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k' 33 I
1 With respect to prevention of detonation, i
2 the requirements document has proposed a criterion of 3
13 percent hydrogen concentration as the criterion for 4
prevention of detonation, as compared with the 10 5
percent criterion contained in 10 CFR 50.34(f).
We 6
have similarly provided a technical report that 7
supports this position.
8 We note that if the 100 percent /10 percent 9
criteria that are currently in 10 CFR 50.34(f) are 10 retained, this would pretty much force a large dry l
11 containment to rely on an active control system.
It 12 would not be practical to build a containment of the 13 size and strength required to deal with that without a 14 control system.
15 The strong position of the utilities is 16 that they wish to avoid putting in extra plant systems-17 and equipment, unless they're absolutely necessary for 18 some clear technical need.
19 We would like to continue the technical 20 dialogue with the staff to complete the discussions of 21 both the hydrogen generation question and the 22 detonability concentration question in order to arrive l
23 at a common technical understanding before we jump to l
i 24 any kind of an active hydrogen control system.
l l(..)
25 CHAIRMAN CARR:
I guess my only question NEAL R. GROSS court REPORTERS AND TRANSCRIBERS 1323 RHoDE ISLAND AVENUE, N.W.
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o 34 1
here is are you talking into consideration in your 2
calculations the experiments and the calculations that 3
INEL just got through doing on this that said that 75 4
percent may not be conservative?
5 MR.
SUGNET:
I'm not aware of any 6
experimental or calculation work that INEL is doing.
7 CHAIRMAN CARR:
Okay.
this past 8
MR. SUGNET:
But we do have 9
week we had a meeting with the staff.
It was the 10 first time that we've really gotten down to the
'11 technical issues.
We're going to have a follow-on 12 series of meetings.
I'm sure if those things are r',
13 being done under the commission sponsorship that we
\\
14 will hear about them.
15 COMMISSIONER REMICK:
What gives you 16 difficulty on the containment design?
Is it the 17 additional 25 percent of hydrogen that might burn?
I 18 don't see where the lower concentration would 19 necessarily challenge a containment.
20 MR. SUGNET:
The lower concentration --
21 COMMISSIONER REMICK:
Means igniters, 22 probably.
23 MR. SUGNET:
The lower concentration means 24 that you can' t stay below the 10 percent concentration s'
25 limit in a reasonable size containment.
To meet the NEAL R. GROSS CoVRT REPORTER $ AND TRANSCRIBER $
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35 1
10 percent concentration limit for an ALWR would 2
require something on the order of a four and a half 3
million cubic foot containment, and this is simply 4
larger than is economic to build and so this would 5
dictate an active control system.
We would prefer not 6
to go to that measure ' unless we are all convinced 7
technically that that's necessary.
8 (Slide)
The next chart gives a little bit 9
of the history of resolution of the hydrogen issue.
10 We submitted a technical report to the staff in early 11 1989.
We met with the staff in June of that year, and l
12 as a result of some of their comments revised some of 13 our analyses and did some more sensitivity cases and j
14 resubmitted a revised report in November of last year.
15 This past week we had a technical meeting.
16 We had tried to schedule one earlier and because of 17 our industry needs we had had to reschedule that l
18 meeting, but we had a good technical dialogue last l
l 19 week.
We did not get down all the way to,a comparison 20 point by point of our evaluation cases versus the 21 staff's and we'd like to do that to see if we can 22 understand the reasons for the difference of technical 23 position.
And we think once that's done, then we will 24 be in a
position to know better where these t -
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..A
E 36
,e-1 for any kind of control system.
2 (Slide)
With respect to the containment 3
performance area, on the next two charts I have shown 4
in summary form the requirements contained in the ALWR 5
requirements document to assure good containment 6
performance.
We've divided them into t'wo groups.
The 7
first chart addresses those that are part of the 8
design basis and the second chart shows items that are 9
what we call saf ety margin basis.
That is, they are 10 contained in the requirements -locument.
They are 11 called requirements, but' they are outside the i
12 traditional licensing cases.
13 on the first chart, in the design basis 14 cases, we absolutely require a rugged containment for 15 an ALWR irrespective of what the predicted accident 16 frequencies are.
We call for the containment.
We 17 specify its requirements.
It is a design pressure j
18 containment based on the double-ended break loss of 19 coolant accident pressure.
We evaluate the 1
20 containment integrity during an_ accident, including a i
21 global burn of 75 percent hydrogen.
And we include heat removal systems, 22 requirements for containment 23 cont.
Iment isolation systems, spray systems, and so to meet all the existing regulatory 24 forth v
25 requirements.
So that's our design case.
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37 1
In addition to that, in the safety margin j
!m 2
basis area, we have specified a core damage frequency 1
3 of less than 10-6 per year of exceeding a site 4
boundary dose of 25 rem; and in addition to that, a 5
number of deterministic design requirements that are 6
intendeck to cut off all of the identified mechanisms 7
for causing failure of the containment.
Let me give 8
you some specific examples of this.
l 9
We mentioned before the measures that we 4
10 have taktm to reduce the likelihood of a prolonged 11 station blackout to what we consider to be a 12 negligibly low likelihood.
m.,
13 We have improved the heat removal
+
14 capabilities from the containment, three full trains 15 for the boiling water reactor, a reliable two-train 16 for the pressurized water reactor.
17 We have specified higher pressure 18 interfacing systems to rule out the likelihood of an 19 intersystem LOCA that would cause a bypass of the l
l 20-containment.
21 We have specified a cavity area and a 22 capability to flood the cavity rapidly with large 23 amounts of water to cool core debris in the event of a 24 core damage accident that breaches the reactor vessel.
l{' (..,(
25
.We've specified a
large strong NEAL R. GROSS CoUR7 REPORTERS AND TRANSCRit(R$
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38 1
containment, as I described a few minutes ago, h
2 And we've included requirements for 3
reactor depressurization system capabilities to 4
minimize the possibility of a high-pressure core melt 5
ejection situation.
6 So we think that we have done a great deal 7
to address the issue of containment performance.
It's 8
our position that the ALWR requirements are 9
satisfactory from a standpoint of meeting the 10 commission's safety goal policy and the severe 11 accident policy statements.
12 Our preference is to address any credible 13 challenges to the containment frontall'y in the design, 14 so that there is no need for reliance on something 15 like a containment vent to assure that the containment 16 isn't failed early in an adverse way.
So our 17 preference is put in design requirements to deal with 18 the issue ~, as opposed to intentionally putting a vent 19 path into the containment.
20 There has been quite a discussion about 21 containment performance criteria, including the 22 concept of conditional containment failure 23 probability.
We have not included a conditional 24 containment failure probability criterion in our sc 25 requirements document.
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I x__--_______-__-__________---__-_
39 n.
-0.
1 not included it is because it would be a disincentive e
2 for a designer to reduce core damage frequency.
3 The simple example, if you have a design 4
that is exactly at 10-8 core damage frequency and 5
10-6 of the 25 rem dose, any reduction in core damage 6
frequency immediately would put you out of compliance 7
with the conditional containment failure probability.
8 We don't think we want the designer to be in that kind 9
of a predicament, 10 COMMISSIONER REMICK:
Isn't there still an 11 economic incentive, though, whether the designer cares 12 to do it or not, to keep that core damage frequency
~.
13 low?
N:;...
14 MR. SUGNET:
There is.
On the other hand, i
15 if he were required to meet a particular conditional
~
16 containment failure probability, then he would also 17 have to reduce the likelihood of significant release 18
.by'the same factor as he reduces core damage frequency 19 and this can be difficult to do.
The more you --
l 20 MR. LAYMAN:
It would not be economic, l
21 MR. SUGNET:
The more that you do to deal 22 with the easy sequences, the more difficult becomes 23 the residue to control.
'24 The other problem that we have with the C
25
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40 1
it relies on knowing how to define what constitutes
('
2 containment failure.
In other words, do you define it 3
in terms of dose to the public?
Do you define it in 4
terms of mass leakage from the containment, or some 5
other definition?
And it also relies on the numerical 6
calculations, which we know are uncertain.
7 Admittedly, the s anie uncertainty exists in our 10-8 8
and 10-6 criteria.
It would simply be compounded if 9
carried into another criteria.
10 MR.
KINTNER:
What we agreed with the 11 staff in our discussions Thursday, there really does 12 need to be some intelligent criteria on which 13 containments are tested.
Just saying
.1 doesn't seem (q,
- ., )
~
14 to be enough.
And I think the ACRS is working on this 15 subject.
I think Brookhaven is working on it too.
16 We've agreed to go back and try to write 17 down a set of criteria by which containments can be 18 designed and tested and to come back to the staff with 19 a proposal and discuss that with them.
This is 20 obviously a very, very significant subject in the 21 long-run and one which just
.1 doesn't do what 22 anybody wants to do, I don't think.
23 MR. SUGNET:
I'd like to reiterate that we 24 definitely are willing to discuss this, study it 25 further, dialogue with the staff further.
On the NEAL R. GROSS CoVRT REPORTER $ AND TRANSCRIBER $
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1 other hand, we would like recogrition that we have 2
gone a long way in the deterministic features that are J'
3 already included in the ALWR requirements document 4
towards cutting off the likely ca.ses of containment 5
failure in a core damage accident.
6 Let me move on to the last issue, the ALWR 7
source term issue.
Ed alluded earlier to the desire 8
to bring to bear recent decades of new information in 9
the design of advanced light water reactors.
We 10 believe that this source term area is a very fertile 11 area in that respect.
There has been a great deal 12 about radionuclide behavior learned in the last few 13 decades and we would like to capitalize on that to 14 modernize the source term from where it ic now.
15 The TID source term which is current 16 regulatory practice was developed in 1962.
As a point 17 of 6eparture, we would like to incorporate the new
-18 knowledge to bring that up to snuff and to help 19 produce a more rational system design basis in the 20 process.
21 The things that -- the kind of things that 22 would be affected, for example, would be a slower 23 valve closure time limit that could allow a better 24 valve design for leak tight isolation and reduce the 25 maintenance burden on the plant in this area; allow NEAL R. GROSS court REPORTER $ AND TRAN$CRlllR5 1323 RHoDE l$ LAND AVENUE, N.W.
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42 1
realistic credit for scrubbing from a boiling water h
2 reactor suppression pool; and realistic hold-up in the 3
piping systems and in the buildings for both 4
pressurized and boiling water reactors.
5 We would also like to relax slightly the 6
allowance on allowable containment leak rate to 7
provide the opportunity to reduce the maintenance 8
burden and the likelihood of repeating containment 9
leak tests, which are difficult and expensive, and 10 still have a very satisfactory protection of the 11 public.
So we foresee the pursuit of improvement and 12 modernization of the source term as providing the 13 opportunity to achieve some of these benefits.
14 COMMISSIONER REMICK:
I always thought i
l 15 that one of the advantages of the subatmospherie l
l.
16 containment was the fact that you had an ongoing check l
17 on the tightness.
Has this been considered in your l
l 18 requiroments document at all, the advisability of 19 that?
20 MR. SUGNET:
We have just discussed last 21 week with the staff a concept which we are probably 22 going to require in the ALWR requirements document.
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rates.
We would be able to -- probably not to detect 2
something as small as design basis leakage, but we 3
certainly could detect any significant opening in the 4
containment and we think that's a prudent thing to do.
5 It does not add any significant amount of equipment or 6
burden to the plant and we will require that.
7 COMMISSIONER REMICK:
Thank you.
8 MR.
SUGNET:
The kinds of things that 9
we're thinking of doing in the source term area are to l
10 broaden the consideration of fission isotope releases.
11 Currently, the TID source term, in simple terms, deals 12 with norle gases and iodine as the surrogate for ala 13 fission products.
There is new knowledge available I
(,.,)
14 now that can allow us to separately describe the 15 various fission products.
We think that that's the 16 way nature really behaves and we think that's the 17 right thing to do for the plant design considerations, j
18 The original prescription for source term 19 was to have an instantaneous release.
We think that 20 that is certainly not physically accurate and can lead i
21 to some bad design practices, so we want to pursue a 22 more realistic timing of the overheating of the core 23 and the release of fission products to the reactor 24 coolant system to the containment and then to j.
k.
25 atmosphere.
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We want to use the best available
('
2 inf ormation on the chemical and physical forms of the 3
radionuclides.
- Again, this points you in the 4
direction of a more effective and rational set of 5
containment systemt 6
More realistic treatment of deposition of 7
aerosols.
We understand that a large fraction of 8
fission products will be in aerosol form, therefore we 9
need to do a better job of characterizing the 10 retention of those aerosols.
11 We have undertaken a technical dialogue 12 with the staff.
Just this past week we had an 13 extensive meeting.
They told us what initiatives
(
14 they're undertaking.
We described to them the work 15 that we have done.
I think we are both moving in the 16 same direction.
We are very pleased with this 17 development, that there is a movement within the staff 18 now to revisit the source term and to try to make it a 19 better source term.
20 And we would like to achieve some 21 generically applicable statement of the source term 22 improvements that can be, again, relied on and used 23 industry-wide, rather than any specific application 24 type of treatment.
25 So that completes my discussion of the 15 NEAL R. GROSS CoVRT REPORTERS AND TRANSCRIBERS 1323 RHoDE ISLAND AVENUE N W.
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45 1
technical issues.
Let me ask John Taylor to
(
2 summarize.
3 COMMISSIONER REMICK:
Before going to 4
that, just a quick question.
Do you feel that there's 5
any international consensus of peers on that source 6
term issue?
7 MR. SUGNET:
We've had a --
8 COMMISSIONER REMICK:
I realize you'd 9
never have a perfect, but --
10 MR.
SUGNET:
We've had a six man group 11 working on this for a little lese than a year now, and 12 in that group we have represented people from the 13 Idaho laboratory who did a lot of the experimental
(
14 work early-on.
We have utility involvement.
It has a 15 fairly broad representation on it.
And that group has 16 come to a consensus on a number of points, so I think 17 there is hope in this area.
And I think that if we 18 get down to a careful description of what the event is 19 that we're trying to describe and then get the best 20 scientists together, I think they can come to a 21 consensus on this.
22 MR.
TAYLOR:
I don't
- believe, 23 Commissioner, there's yet an international consensus 24 on this subject.
We however have in the program t
25 representation, through the steering committee and.
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through staff involvement both, of most of the major
- Japan, Korea,
- Taiwan, I
2 organizations overseas and expect that to 3
France, the Netherlands, Italy 4
be enlarged.
And we're hoping that through this 5
process working it out in detail, we'll achieve 6
ultimately a consensus.
I think it's very important 7
we do.
8 MR. SUGNET:
John, let me add one other 9
comment about this issue, and that is we are trying to 10 arrive at a deterministic single source term to be i
11 applied for several design provisions, things like 12 qualification of equipment, calculation of exposures 13 in the control room, these sorts of needs for the
(
14 design, shielding.
i 15 We think, given that there will be a PRA 16 for these modern plants that will the whole spectrum 17 of events and for each of those events it will define 18 an appropriate source term based on the types of 19 failures that have occurred, that perhaps some of the 20 burden is relieved to be completely bounded for this 21 single deterministic case.
We think perhaps it m'ay be 22 more appropriate to try to come up with a realistic 23
- case, an expected case, and make the design source 24 term deal with that expected case and then consider
(-
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of the PRA and the risk evaluation, t
2 MR. TAYLOR:
- Well, let me sum up very 3
briefly.
As you hear, we really believe that the ALWR 4
requirements provide an opportunity and mechanism for 5
technical resolution of issues in keeping with the 6
standardization process by defining industry-wide 7
resolution in the safety evaluation report of the 8
requirements document, which then would be formalized 9
in subsequent design certification.
and we're very grateful for 10 We believe 11 your support for this approach, but have been 12 concerned from the discussions in the May 3rd meeting 13 and some of. the statements on case by case treatment 14 in SECY 9 0. 016.
But we see the process working, 15 although substantially more ' chnical dialogue is 16 needed in our judgement with the
'aff.
Since May 17 3rd, we've had four days of intensive discussion with 18 the staff, which is actually more discussion than 19 we've had on the evolutionary requirements since we 20 started working with the staff, so we're encouraged by-21 that movement ahead.
22 on the passive plant, we already have a 23 more favorable picture of that interaction.
A large 24 number of senior staff people visited EPRI and spent 25 two days with us discussing where we stood on the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHoDE ISLAND AVENUE. N W.
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passive plant work, and we understand that the staff il 2
is arranging for meetings with the reactor 3
manufacturers to go into substantial detail in the 4
test results they've achieved thus far and their 5
continued testing program plans.
We're very, very 6
pleased to see that.
7 But we want to be sure that this technical 8
dialogue is continued on a very timely basis in the 9
hope that we can resolve.
Not that we're demanding 10 that everything that we say is right, but that we sit 11 down as openly as we know how with all the data 12 available and come to the right conclusions.
13 We don't think there's a need for generic 14 rulemaking.
We've heard about those discussions.
As 15 we've talked in the meeting here today, think it's p
16 undesirable to absorb into the regulations the margins 17 that we're identifying in the requirements document.
18
- Finally, the Nuclear Power Oversight 19 committee, which as you know is the top executive 1
20 industry-guiding body, recently formally endorsed our l
21 program and its goals and reinforced their strong l
22 conviction that the regulatory stabilization which we 23 think can be achieved through the processes we're j
24 discussing here, is an essential enabling condition 25 for considering any new U.S. nuclear plant.
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Thank you for the time you've given us.
t i
's 2
CHAIRMAN CARR:
Okay.
Before we go for 3
questions, we ' re -- a couple of us are going to have-4 to leave in about 15 minutes.
So, if you can make 5
those questions crisp and the answers crisper, we'll 6
proceed.
7 COMMISSIONER REMICK:
You indicated that 8
you applaud the staff working with the vendors and 9
looking at experimental data and facilities.
10 MR. TAYLOR:
Yes.
11 COMMISSIONER REMICK:
Also, some vendors 12 have submitted what I would call conceptual documents.
13 Do you see this in any way undercutting your efforts 14 if our staff works with the vendors on those 15 conceptual documents?
16 MR.
TAYLOR:
It's awfully important, 17 commissioner, that the staff have full visibility of 18 the work that's going on.
So, we encourage that.
19 Now, if it's converted into try and make decisions and 20 get, for the passive plant, the cart before the 1:orse, 1
l 21 as commissioner Curtiss has described it, then it's 22 clearly wrong.
We've had recent discussions with the l-l 23 vendors and have their assurances that in these 24 discussions there's not going to be that the 1
l' 25 process isn't going to be subverted.
I'm reasonably 1
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confident that we will work that out in the proper 2
manner.
But to say to the staff, " Don't come and talk 3
to the vendors," to me would be in error, i
I 4
MR.
KINTNER:
What we're afraid of is 5
auctioneering.
6 COMMISSIONER REMICK:
Yes, I understand.
i 7
Okay.
8 I don't have any problem understanding 9
your concerns for the ratcheting and a preference for 10 having things codified in the certification rulemaking 11 versus regulations.
I wonder to what extent your 12 concerns include that we might codify in the 13 regulations certain requirements for the evolutionary
'\\
14 plants that would then lock your hands on what I call 15 the true advanced light water reactors that you 16 referred to earlier that DOE and EPRI are funding and 17 so forth.
Are those some of your concerns if we 18 codify --
19 MR. KINTNER:
Yes, they are some of our 20 concerns.
But we think, as John says, that the staff 21 is, in fact, beginning now to work with us in the 22 passive plant and trying to identify the differences 23 so that these can be sorted out.
In some cases, in 24 the May 3rd meeting, they identified that they l
25 intended this decision to carry on into the passive NEAL R. GROSS CoVRT REPORTERS AND TRANSCRIBERS 1323 RHoDE ISLAND AVENUE, N W.
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1 i
51 1
plant.
So, we do have that concern.
We do think that 2
there does need to be a somewhat different viewpoint 3
in the passive plant.
4 COMMISSIONER REMICK:
Okay.
I don't want 5
to put our General Counsel on the spot, but I wonder, 6
do you have any comments in light of what you heard 7
today on generic rulemaking?
I think at the previous 8
meeting, Bill, you indicated that ideally that was a 9
preferable route.
10 MR.
PARLER:
- Well, I
think that the 11 obvious has been tasked and will shortly be tasked in 12 looking at that.
I'd just as soon do it all at one i
13 time.
Of course, the word " requirements" has been 14 used quite frequently at this meeting this morning anc 15 where everything is fine if folks agree on the so-16 called requirements, but if the requirements are not 17 expressed in the regulations after a rulemaking action 18 or in the certification proceeding, the guidelines, 19 wnich are not requirements, could be fair game to be 20 challenged.
21 If you have a certification proceeding and' l-l 22 you're going to impose requirements which differ from I
23 the requirements in the existing regulations, that is 24 a fertile field for challenge and a prolonged process.
!k.
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52 1
tell you when I report to you formally.
(
2 COMMISSIONER REMICK:
Thank you.
3 CHAIRMAN CARR:
Commissioner Rogers?
4 COMMISSIONER ROGERS:
- Well, I know our 5
time is limited, but I wonder if you could say a 6
little bit more about your concerns with respect to 7
regulatory stability, just exactly what you're talking 8
about.
We hear these words constantly as an industry 9
concern, regulatory stability.
I have a feeling they 10 mean different things to different people.
11 What's your particula-cracern?
Are you 12 most concerned right now about the new designs, the 13 preoperational aspects of regulatory stability?
Are 14 you concerned about regulatory stability after plants 15 are built and in operation?
Where do you see this--
16 the real center of your concern with respect to 17 regulatory stability?
18 MR.
TAYLOR:
Commissioner, our concern 19 because of our role is in the preoperational stage.
20 It reflects the utility's strong conviction that they 21 don't want to be involved in major expenditures of 22 funding until they have an understanding of what will 23 be required in a - new plant by the Nuclear Regulatory 24 Commission.
25 The other issues are equally important and v
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7 9
+
53 I
would come after this phase and are being addressed 2
today by NUMARC in their ITAAC program and in the 3
dialogue which is underway with the staff.
That is 4
equally important and there are equal concerns in that 5
area which NUMARC is pursuing with you.
6 COMMISSIONER ROGERS:
Okay.
Thanks.
7 CHAIRMAN CARR:
Commissioner Curtiss?
8 COMMISSIONER CURTISS:
I just have two or 9
three quick questions here.
10 On your last graph there, I'm not sure I 11 understand what you mean when you say that completion 12 of the evolutionary requirements document roll-up 13 without NRC staff, DSER input will be necessary.
Why 14 is that?
15 MR.
SUGNET:
The process hat we had 16 followed was to provide-a chapter-to the staff, have 17 their review and get a draft safety evaluation report, 18 then deal with the issues in that report, finalize it 19 and get a final safety evaluation report.
Because of 20 the timing, we have to proceed to close out now and 21 finalize Chapter 6 through 13 without any further 22 draft safety evaluation input from the staff.
23 COMMISSIONER CURTISS:
Okay.
Based upon 24 what you've done so far with the requirements 25 document, where you see it heading on the passive NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE N W.
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plants, do you continae to see a need for a licensing 2
review basis type document for individual vendor 3
design reviews?
4 MR. SUGNET:
I think that there will be a 5
need for a licensing review basis document to deal 6
with some things other than technical things for 7
certain.
We have, in the last two weeks, reached 8
agreement with the vendors in the Department of Energy l
9 to work together to define what the content of the l
10 licensing review basis should be, which elements in i
11 that should be in lock step with the requirements 12 document and which of the.m can proceed independently.
13 Things like administrative review schedules, manpower s
14 commitments, these sorts of things certainly don't J
j 15 need to be held up for a review of the-requirements I
16 document.
l 17 COMMISSIONER CURTISS:
Well, to take the l
l 18 one that we've completed to date, the GE'ABWR, which
{
1 19 addresses a number of technical issues, from the i
]
20 standpoint of technical issues, you don't see a role j
21 for an LRB?
i 22 MR. SUGNET:
We will trrange for the LRB
\\
\\
L 23 to be.in lock step with the requirements.
It may be l
i l
24 desireable to deal with those in the liRB for the needs i
25 of the applicant and the staff, but if so, it should NEAL R. GROSS CoVRT REPORTERS AND TRANSCRIBERS 1323 rho 0E ISLAND AVENUE. N W.
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55
__O
1-be held until the - requirements document is resolved 2
and then implemented in that same way in the LRB.
3 COMMISSIONER CURTISS:
Okay.
All right.
4 On the relationship of the requirements 5
document to the individual vendor design. reviews, the 6
so-called horse / cart question, for the passive plants
-7 where we have decided that the Commission review of 8
the requirements document should be complete before 9
individual vendor LRBs are submitted - to the ACRS for 10 review and approval, assuming sufficient resources to 11 carry out the review of the EPRI requirements 6
12 document, is that a horse / cart relationship that about 13 approximates what'you all --
i.
4 14 MR. KINTNER:
We think that's great.
If 15 it's carried out that way, it will be very helpful.
y 16 COMMISSIONER CURTISS:
Okay.
One final 17 question, really not squarely on the topic here.
But 18 based upon the review that you've undertaken, do you 19 have any thoughts.on the question of level of design 20 detail or is that something that's going to be 21 addressed strictly in the NUMARC context?
22 MR. TAYLOR:
Again, as I mentioned, that's a..m 23 a NUMARC area and. Byron Lee is here.
I think I'm 0
24 going to ask him to comment.
.m 25 MR. LEE:
Yes.
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56 c:
1 CHAIRMAN CARR:
Would you go to the j[!':
2 microphone, please, and identify yourself?
l
-3 MR. LEE:
Byron Lee from NUMARC.
4
- Yes, we will be. handling the design 5
completion aspects, Commissioner.
In fact, we have a 6
meeting with the staff management later this vreek and 7
we have arranged a-briefing of the Commission on the 8
ITAAC design complation information on July 16th, I 9
believe it's tentatively set.
10 COMMISSIONER CURTISS:
Okay.
That's-all I 11 have.
12 CHAIRMAN CARR:
Can you give us a copy of 13 the-resolution that the utilities passed?
14 MR. K1NTNER:
Absolutely, yes.
l 15 CHAIRMAN CARR:
I'd be interested in --
l 16 MR. KINTNER:
'I thought we-already had.
l 17 MR.
TAYLOR:
I. sent a copy of that to=
L P
18 Commissioner Curtiss in light of some questions he had l
l 19 raised.
20 CHAIRMAN CARR:
- Okay, i
21 MR. TAYLOR:
I'll see to if that all of L.
the Commissioners get a copy.
22-23 CHAIRMAN CARR:
He'll share it with us.
.24 MR. KINTNER:
One other thing I was going 25 to mention and we should really have one if you NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. NW (202) 234 4433 WASHINGTON, D.C. 20006 (202) 232-6600
57 1
haven't already-seen it.
We've completed Volume 1, a
2-top level document for both evolutionary and passive 3
plant.
I think it's a very impressive piece of work j
4 by everyone who participated
)
-)
5 Have those copies been sent?
'6 MR.
SUGNET:
I believe -some copies have 7
been sent to the SECY Office.
8 MR. KINTNER:
We'll get you a copy of that 9
as well.
10 CHAIRMAN CARR:
How do you envision -- at i
1 11 the end of the time when the requirements document is 12' finished, what do you see as. the way we put our 13 imprimatur on this thing to make it -- as the General 14 Counsel
- says, how is it going
.t o.be really a 15 requirement?
16 MR. - SUGNET:
The way we envision that 17 occurring is that the staff safety evaluation report 18 will-state their agreement that the requirements 19 proposed will be licensable.
This would have the same 20 weight as a safety evaluation report on a-normal 21 design application.
22' CHAIRMAN CARR:
Well, are we net, in fact, 23
. making that part of our regulations?
24 MR. SUGNET:
I don't think you are.
l s
k 25 CHAIRMAN CARR:
It depends on how we write NEAT. R. GROSS court REPORTER $ AND TRANSCRIBER $
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1.
. it, I guess.
2 MR. SUGNET:
And then following that, that the proposed design and the 3
-the certification 4
certification process would actually make it a part of 5
the regulation.
At that point it would be locked out, g
.6
.MR.
PARLER:
Mr. Chairman, I realize the 7
time is important here, but you can't make anything a 8
part of regulations without going through rulemaking 9
procedures and opportunity for the public to be on 10 notice and to comment.
So, that's a detail --
11 CHAIRMAN CARR:
Yes.
I'm trying te figure 12 out how we're going to get this thing done in that 13 MR. SUGNET:
I think that the requirements s-
,m
- m' 14 document-review and staff acceptance in the'SER is an 15.
informal understanding and it's formalized when the w
-16 design is certified.
Ii 17 CHAIRMAN CARR:
Okay.
.It's interesting to l
18 me, you said something that I've kind ~of been saying Ji a.
n
.19 all along.
'There.'s not all the rush in doing this so I
,,.y-
[
20 that;we: don't do it right this time.
We don't want to 21 build another hundred like we built the last hundred, 22 and so we want to do this differently.
l 23 In your -- the reason I ask for that 24 resolution, I'm trying to find cut'if there's an i
25
. indication of us still having time to do that or are l
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the utilities getting eager to get one of. those D
2 evolutionary advanced designs certified so they can s
3 start construction?
Do you get any indication of that-4 in your --
5 MR. SUGNET:- Maybe John could talk to --
m
'l,
6 CHAIRMAN CARR:
Do you get a sense of v
~
7 urgency that there are people pressing you to get your 8
work done?
I
, MR.
KINTNER:
We're working with this o
10 INPOC subcommittee and I think the fact that such a 11 statement was made and such an effort tb begin is P
12 itself significant.
But I don't see, quite frankly, a G.(
13 great urgency from any utility in the United States to
- \\',)
14 go buy a reactor plant.
Now, it may very well be that
~
15 there; is or it may also be that once certified and 16 everything is worked out, they can feel comfortable 17 with proceeding and' they will proceed.
But I don't 18 see that as a driving force on getting it right before 19 we step off in the next generation.
i 20 CHAIRMAN CARR:
It certainly appears to me 21 that you're concern about regulatory stability goes 22 away if we have what we have defined as an essentially 23 complete design when we certify it.
Then there isn't 24
-any lack of stability to be if you build that i.L 25 plant, you build that plant.
Is that not --
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MR. TAYLOR:
The'first step, which we are k
2 trying to pursue, commissioner, is to have an 3
understanding of what is needed before a trem'endous 4
expenditure of money is placed on getting that 5
detailed design.
A second step which NUMARC is-6 fo31owing will be a process by which verification can 7
be established that the principles have been agreed to 8
in the regulations that have been --
9 CHAIRMAN CARR:
Is that money that's--
10 MR.
TAYLOR-sent through the 11 certification will be met as the plant is designed, 12 detailed and constructed.
13 CHAIRMAN CARR:
That money that's going to 14
.have to be spent on that detail design is going to 15 have to be spent at some point in time.
16 MR.
TAYLOR:
And the issue is spend it 17 with some assurance you're going to get your money 18 back in terms of a plant that will run.
19-CHAIRMAN CARR:
The more complete that 20
. design is when it's certified, the more likely 21 everybody is going to know what's in it.
That's 22 motherhood, right?
23 Commissioner Remick, you had one more 24 questions?
25 COMMISSIONER REMICK:
Does EPRI envision a NEAL R. GROSS COURT REPORTERS AND TRANSCRl8tR5 1323 RHODI ISLAND AVENUE, N.W.
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requirements document for either the advanced liquid I
- f. g M ')
2 metal react.or, as it's called now, or the modular
\\;p 3-HTGR?
4 MR.
TAYLOR; The concept-of the 5
owner / operator establishing as a base a set of 6
requirements that_ reflect his needs as the ultimate 7
owner and operator has been accepted not only by the 8
advanced systems such as gas-cooled and liquid metal 9
in the U.S.
Department of Energy is sponsoring 10 developing requirements for both of those.
But also 11 in the new production reactor program where DOE is 12 also asking for requirements and by movement overseas,
~
13-in individual countries and by the International (g%
W 14 Atomic Energy Agency to establish requirements.
15 Hopefully, and I think that'is the case at 16 this point, a substantial -amount-of-leaning on what 17 we've done to date is going on.
18 COMMISSIONER REMICK:
But you have no 19-specific plans at EPRI now for req:.irements documents 20 for those two --
21 MR. TAYLOR:
We do not have-the resources 22 to sponsor requirements for the liquid metal and gas-23 cooled systems.
That would have to be done by those 24 who are more directly involved in funding those 25 programs.
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62 1
COMMISSIONER REMICK:
Thank you.
2 MR. LAYMAN:
GCRA has written requirements 3
document for that.
4 MR. TAYLOR:
They've taken a step.
5 MR. LAYMAN:
HTGR is the equivalent, maybe 6
half an inch thick at this point in time.
7 COMMISSIONER REMICK:
Okay.
8 COMMISSIONER CURTISS:
Ken, I just have
'I 9
one quick question.
10 Awhile back we set out in a NUREG the 11 process and the relationship _between the staff.and the between the staff and EPRI on how we're going 12 NRC 13 to review the requirements documents.
I've assumed c
14 throughout this discussion that that document which 15 was promulgated in, what,
'86 or
'87, thereabouts, 16 still provides a useful and relevant approach.
Is now that it's two 17 there anything that the document 18 or three years old, I'm assuming that it still 19-provides the framework for how we intend to approach 20 this.
21 MR. SUGNET:
I'm not sure which document 22 you're referring to.
But my response in general would 23 be we think that we r.eed to have more freedom to have 24 open dialogue with the (M.a f f on these issues.
Our
- )
25 understanding du that a lot of the discussion priority NEAL R. GROSS ~
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and process in the staff's eyes has constrained them-
'k
'2 not to discuss some of these technical issues with us.
3 We think that that hasn't been helpful.
So, we would 4
suggest as open a process as you think is appropriate.
5.
CHAIRMAN CARR:
- Well, I'd like to thank 6
the ALWR Steering Committee for providing the 7
Commission with your views on advanced light water 8
reactor certification issues.
The Commission believes l.
9 the requirements document is a valuable vehicle for j.
l' 10 identifying those advanced reactor design 11 characteristics desired by the utilities who will-12 purchase the new designs.
13 I'n addition, it provides the mechanism for-
.s
.i -.
14-resolving issues in a generic way as opposed to i
i 15 dealing with them individually for each specific L
reactor design.
Recognizing-the value of this 16 17 document, the Commission has set its review priorities 18 for advanced reactors accordingly.
1 L
l 19 Do any of my fellow Commissioners have l
l.
20 additional comments?
l 21 If not, we stand adjourned.
22 (Whereupon, at 10:29 a.m.,
the above-l 23 entitled matter was concluded.)
1 1
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25 NEAL R. GROSS COURT REPORTER $ AND TRANSCRIBER $
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- ,1
'.~s CERTIFICATE OF TRANSCRIBER
--:+
s-This is to certify that the attached events of a meeting of the United States Nuclear Regulatory. Commission entitled:
TITLE OF MEETING: BRI5FING'BY ALWR UTILITY STEERING COMMITTEE ON
' ADVANCED LIGHT WATER REACTOR CERTIFICATION ISSUES PLACE OF MEETING:.ROCKVILLE, MARYLAND DATE OF MEETING:
JUNE 4, 1990 were transcribed'by me. I further certify that said transcription is accurate and complete, to the best of my ability, and that the transcript is a true and accurate record of the foregoing' events.
dA mu
' "U '
~
Reporter's name:
Peter. '.fnch Ly e
i I
D k
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~.,_,.. _._
.f g J
r L.
l' i
PRESENTATION TO NRC COMMISSIONERS UTILITY / EPRI ALWR PROGRAM RESOLUTION OF EVOLUTIONARY PLANT KEY REGULATORY ISSUES m
E. E. Kintner Chairman, ALWR Utility Steering Committee J. J. Taylor / EPRI W. H. Layman / EPRI-W. R. Sugnet / EPRI l:
June 4,1990 L
y
i Utility /EPRI Presentation to NRC Commissioners ALWR Program Resolution c
of Evolutionary Plant Key Regulatory issues a
June 4,1990 Advanced LWR Program ALWR Program is a UTILITY-driven Program ALWR Utility Requirements are technically based, with major emphasis on simolification and margin industry recognition and support formalized by Nuclear Power Oversight Committee endorsement of ALWR Utility Steering Committee and EPRI ALWR Program
- The ALWR Utility Steering Committee represents utility industry with NRC and vendors
r Utility /EPRI L
Why We Requested l
This Meeting.
. ALWR Requirements not fully represented in the 5/3/90 Commission Meeting Extensive recent progress in resolving
.keyissues
. SECY 90-016 would absorb some margin into regulatory requirements Advanced LWR Program
~
L Current ALWR Requirements for severalimportant issues were not fully
' ~
represented in the 5/3/90 Commission Meeting lack of technical dialogue between Staff and ALWR Program (Chapter 5 l
DSER took 27 months; process discussions major contributor to delay)
Staff review did not completely account for a few ALWR Requirements and 4
I i'ssponses 8 month delay-in Chapter 5 DSER between completion and issuance Effectiveness of ALWR Requirements in resolving key issues is greater than could be inferred from the 5/3/90 meeting discussion:
Mid-loop Station Blackout 1
- Fire Protection Inservice Testing of Pumps and Valves
. - Unresolved issues for which ALWR position not fully represented:
Safety Goal Hydrogen H
Containment Performance / Vent L
Source Term On some issues, SECY 90 016 proposes to adopt ALWR Requirements as regulatory requirements, thus eliminating margin to regulation E
l
J.-
Utility /EPRI Industry-Wide issue Resolution
. ALWR Requirements Document SER E
provides mechanism for NRC Staff to indicate acceptance of issue resolutions prior to Design Certification
. Thus generic rulemaking for ALWR issues may be unnecessary
. Generic rulemaking would cause major delay and is thus undesirable Advanced LWR Program Re' gulatory stability not assured if issue resolution is on application 3
by application basis.
l ALWR Requirements provide sufficient basis for generic resolution.
Where PWR/BWR distinctions are necessary, Requirements provide that detail This mechanism could supplant case by case resolution for some of the issues discussed in SECY 90-016 Generic severe accident rulemaking prior to Certification EPRI and NUMARC letters of January 9,1989 explained why
_ generic rulemaking is neither necessary nor desirable
- Concept of " parallel" rulemaking discussed 5/3 appears unnecessary if ALWR DSER is acceptance basis and Certification rule locks-in this resolution for the design.
Generic rulemaking would cause major delay in Certification Regulatory optimization is appropriate in selected areas, as supported by technical basis l
l 1
l '
7-l.
4
'Jtimy/EPRI Relationshia to Evolutionary Plant Certification
. ALWR Utility Steering Committee working closely with reactor suppliers
. The Committee does notwant to stand in the way of Evolutionary Plant Certification
. The Committee dent want to continue dialogue on open lasues to a technically-based. stable resolution Advanced LWR Program The ALWR Utility Steering Committee is working closely with reactor suppliers on implementation of the ALWR Requirements-to develop designs that meet the perceived 'need of the utilities for Saig,- reliable and economic ALWRs
. - The Committee does not want technical d!alogue on the Requirements Document to stand in the way of Certification of Evolutionary Plant designs that will demonstrate the Certification process, and will provide near term options to the marketplace The Committee do.ca want to continue dialogue on open issues to a technically-based, stable resolution l
l
= - - _ _ _ _ _ - _ - _ _ _ _ - _ _ _ _ - _ - - _ _ _ _ _ _ _. - _ - - _ _ _ _ _ _ _ _ _ _ _
'g.,
{ Utility /EPRI D
i Design Margin to Regulation
. Stability in design process sids in fostering investor confidence
. Regulatory margin available for future ese
. Assured licensability at Combined Operating License stage i
I L
Advanced LWR Program u
Margin helps insure stability in design process through Certification for a particular design, helping to foster utility s
management and investor confidence
.i Assured licensability at Combined Operating License stage Regulatory margin continues to be available for future use g
l-Deal with new technical issues in certification review l
- Amendment to deal with new issue after Certification i.
- Available to subsequent designs Public acceptance is added benefit, but not the reason for regulatory margin l
7 tility/EPRI 1
U
(
Regulatory Margin Example--Stat on Blackout
.. ALWR features significantly beyond SBO rule -
large capacity Alternate AC Source
- independent reserve transformer
- generator breaker with load rejection capability j;
. ALWR Requirements overwhelm SBO Issue generically Advanood LWR Program ALWR Requirements go significantly beyond SBO rule:
large capacity Alternate AC Source (AAC) (powers non-safety loads on loss of offsite power; capable of backing up safety loads if needed) independent reserve transformer generator breaker with load rejection capability three tier distribution system improved DC power redundancy and capacity capability to cope for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> before core damage Margin -- requirements provide capability that meets or exceeds hq1ti the AAC option and the coping option in the SBO rule ALWR Requirements resolve SBO issue generically ino'ependent of site characteristics staff approval of SBO issue resolution can be unconditional
9 4
Utility /EPRI Potentially Resolved Issues
. Fire protection
. Mid-loop
. Station blackout Pump and valve inservice testing -
o ATWS i
o intersystem LOCA t
o OBE/SSE o High pressure melt ejection j
o Core debris coolability o Equipment survivability Advanced LWR Program l:
The technical basis for resolution of these issues has been I
developed over.the last two years and ALWR Requirements and NRC Staff positions are converging Further technical dialogue has taken place over the last two weeks on these issues L
Issues marked " " are considered resolved, pending L
confirmation from the NRC Staff Issues marked " o " are converging. Recent technical dialogue has resulted in progress, and in some cases changes in the NRC Staff position.
Once achieved, resolutions of these issues can be accepted in
-the Requirements Document SER, and implemented via the Certification rule for each design that conforms to the requirements L
q l.
t u
-i Utility /EPRI i
)
i lasues Not Resolved
. ' Safety goals
.- Hydrogen
. Containment performance / vent
. Source term i
Advanced LWR Program E
- Current list of unresolved issues for which there are major technical disagreements between the ALWR Requirements and the Staff Positions:
Safety goals L!
Hydrogen -
Containment performance / vent For Source Term, agreement on need for change; differences in approach and technical aspects are under discussion.
Although progress has been made in the last two weeks, technical dialogue needs to be completed on these issues l
1
e s.n.a.
e.
.,.a
,_.x-
..an_
Utility /EPRI Safety Goals and Regulatory Margin Dealqin Procana PRA for Certification Design meets ALWR n g LWR 4
Ta a r and De
-1 Reaulatorv Review
,'g I'*
wh i
p N
AdvancedLWRProgram )
/
L
- - Safety Goals should be the framework in which technical issue priority and resolution are evaluated and decided ALWR Requirements'on Safety Goals are utility requirements
- to vendor, not proposals to NRC for new regulatory requirements This figure shows schematically how the concept of margin to regulatory requirements can be effectively used to provide licensing stability The designer develops his design with the necessary capability and features, and conducts a detailed PRA showing the design complies with the ALWR Requirements for Core Damage Frequency and Offsite Dose -
The NRC Staff reviews the design and the PRA, and confirms that the design is consistent with the Quantitative Health Objectives in the Commission's Safety Goal Policy Statement While there are bound to be uncertainties and technical disagreements over the details of the analysis, they are not likely to be large enough to prevent a successful conclusion p
}
q 1
Utility /EPRI ALWR Hydrogen Control 1
Cladding Oxidation 75% active fuel cladding vs.100%
Prevention of Detonation Concentration < 13% vs.10%
a i
ALWR rolles on containment strength and volume i
Advanced LWR Program Claddina Oxidation The ALWR Requirements document has proposed a Regulatory Optimization to base the deterministic case for hydrogen accommodation on 75% active fuel cladding oxidation.
. ' 10CFR50.34(f) specifies 100% active fuel cladding oxidation as the requirement for hydrogen accommodation; technical basis not well defined A technical report has been submitted to the Staff that considers existing experimental data, analysis results, and ALWR Requirements' supports the 75% considering both in vessel and ex-vessel hydrogen generation.
We note that accommodation of 75% without reliance on a control system requires a i
L more stringent 10CFR50.34(f) evaluation than accommodation of 100% with reliance QD a control system, and can result in a stronger containment Prevention of Detonation L
The ALWR Requirements document has proposed a Regulatory Optimization to establish 13% hydrogen concentration as the criterion for prevention of hydrogen l
detonation i
10CFR50.34(f) requires hydrogen concentration less than 10% as criterion for preventing hydrogen detonation; technical basis not well defined
. A technical report that considers the existing experimental data, energy of realistic t
ignition sources, and ALWR containment conditions and supports this 13% criterion has been submitted to the Staff If the 100% /10% criteria are retained, it will not be practical for a large dry containment strength and volume alone to meet these criteria, and designers will be forced to add the complexity of a hydrogen control system to the design u
i a
Utility /EPRI
)
Hydrogen issue Resolution
. Technical report to Staff early 1989
. Meeting with Staff in June 1989
+ Revised report in November 1989
. Recent technical meetings--dialogue not yet complete Advanced LWR Prognwn Technical report to Staff early 1989 Meeting June 1989 indicated some additional Staff concerns Additional analysis cases in revised report in November 1989 Technical meeting planned for April 1990 aborted due to logistics problems on industry side Technical meeting held May 30. As a followup, the Staff has committed to participate in the near future in a technical dialogue -
on the ALWR Requirements, and the technical basis for the Staff 100% /10% positions.
Q i
y Utility /EPRI
(
\\
Containment Performance i
ALWR Requirements: Licensing Design Basis
. Rugged containment required; design pressure based on LOCA
+ Containment integrity maintained during 1
accident with hydrogen generation from 75%
active clad oxidation (and hydrogen burning j
if not inerted) l
. Containment systems (e.g., heat removal, l
containment isolation) shall meet all regulatory requirements Advanced LWR Program
'i Licensina Desian Basis -- The following summarize the principal design basis requirements for containment:
A rugged containment shall be provided, irresoective of o
assessed core damage frequency, with design pressure based on LOCA Containment integrity shall be maintained during an accident with hydrogen generation from 75% active-clad oxidation (and hydrogen burning if not inerted)'
Containment systems (e.g., heat removal, containment isolation) shall meet all regulatory requirements n
l 1
l l.
i e
f Utility /EPRI i
Containment Performance i
-ALWR Reaulraments: Safetv 18-rain Basis
. Coro damage frequency < 10*per year
. Site boundary dose < 25 rem for 4
accidents with frequency > 10
. Many features that prevent early containment failure (e.g., system to flood corv debris in reactor cavity)
L Advanced LWRProgram i
l l
4
-h Examples of specific requirements for severe accident issues:
Prolonged station blackout made even less likely by combustion turbine l
Improved containment heat removal capability Use higher pressure interfacing systems to prevent intersystem LOCA Cavity / lower drywell spreading area and flooding capability to cool core -
y debris PWR containment size / strength to accommodate hydrogen; control system if necessary BWR containment -- control system required: inerting or igniters Reactor depressurization to address high pressure melt ejection concern 1
i e ***
u-r m.-.
...m.
m
- ^
Utllity/EPRI 4
Utility Steering Committee Position
. Address credible sequences frontally in the design requirements so there is no need for a containment vent Conditional containtnent failure probability can be a disincentive to designer to reduce core damage frequency
. ALWR requirements are sufficient to meet the Commission Safety Goal Policy and Severe Accident Policy Advanood LWR Program The ALWR Requirements are sufficient to meet the Commission Safety Goal Policy and Severe Accident Policy in that they provide a rugged containment with margin and a higher standard of severe accident safety performance than prior designs The Committee considers that any identified issue regarding the adequacy of the severe accident provided by the ALWR Requirements should be addressed frontally in the design as opposed to relying on a containment vent
- philosophically inconsistent for advanced plants to design in a vent path in a rugged leaktight containment
- technical need for vent is eliminated by design features
- there is significant concern for operationalissues related to a containment vent; no existing regulatory policy Use of conditional ccitainment failure probability is not considered necessary, and is not included in Requirements Document because it could be a disincentive to Plant Designer to further reduce core damage frequency l
. 9 e
Utllity/EPRI Scurce Term lasue
. Base ALWR safety on technical knowledge.
updated according to regulatory and industry research
. More reliable containment isolation valves
. Realistic suppression pool scrubbing and holdup in main steam lines and condenser
. Reduced maintenance and test burden for containment and MSIV Advanced LWR Program TID 14844 was developed in 1962 as a " point of departure" a
Incorporate source term knowledge gained from research over the past three decades Desire for ALWR safety to be based on technical facts as opposed to non-mechanistic assumptions which may not be physically realistic Basis for more rational mitigation system design a
Slower containment isolation valve closure time allowing better valve design for better leaktight isolation and less maintenance Suppression pool scrubbing credit including consideration of j
realistic timing of fission product release More rational basis.for evaluating leakage holdup in main
~
steam lines and main condenser allowing elimination of MSIV.
leakage control system Justification of slightly higher allowable containment and MSIV leak rate test limits leading to reduced maintenance burden and reduced likelihood of need for repeated tests
,y
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5
- ""O "O'*
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' ^
t' Otility/EPRI E
ALWR Source Term l
Consider other fission isotope releases More realistic release timing Best available data on chemical and n
physical form L
More realistic basis for aerosol deposition j
L Pursue technical dialogue on generic improvements Advanced LWR Program Retain the approach currently embodied in regulatory guidance which calls for a single source term intended to represent an accident resulting "in substantial i
meltdown of the core with subsequent release of appreciable quantities of fission products" Consider fission product releases to containment other than noble gas and lodine; be more technically realistic with respect to release timing
- - Use best available data on chemical and physical form; use a more technically-
~
realistic basis for aerosol deposition in containment (since the physical form for nearly all of the non-noble fission products is particulate).
-ALWR proposed source term improvements are under active discussion with staff Objective is aenerically anolicable realistic source term for ALWR that allows more rational basis for mitigation system design l
l
o y,-
l Utility /EPRI Conclusion I
. ALWR Requirements provide opportunity maid mechanism for technical resolution of lasues
- Define Industry wide resolution in SER for Requirements Document
- Formalize in Design Certification
. This process is working, but more technical dialogue is needed Advanced LWR Program Technical dialcgue between the Staff and the ALWR Utility Steering Committee on several of these Key Issues has not been completed No Staff response 12/87 - 2/90 (27 months)
Little technical dialogue between the Staff and the ALWR Program occurred on 15 issues prior to 5/3/90 brief Recent meetings 5/22-31/90 have resulted in significant progress Opportunity exists to take advantage of this industry-wide resolution mechanism to pave the way for individual design certification reviews
{
~
1 0
Utility /EPN 1
L Conclusion E
. No need for generic rulemaking
. Undesirable to absorb regulatory margin by adopting new regulatory requirements
. Utilities view regulatory stabillastion as necessary enabling condition for new U. S.
nuclear plant
'l Advenood LWM Program More timely review of ALWR Requirements is needed Chaptms 6-13 DSERs all overdue; no schedule for completion at this time Completion of Evolutionary ALWR Requirements Document l
l "rollup" without NRC Staff DSER input will be necessary Staff resources dedicated to ALWR Requirements review appear to be inadequate Preparations must be made for a much faster review of ALWR Passive Plant Requirements; initiatives being taken now by NRC L
Staff on Passive Plant analytical base and testing are in the right j
direction Utilities consider that regulatory stabilization is an enabling l
condition for new U. S. nuclear plants
. - - - a -
. -