ML20246A221
| ML20246A221 | |
| Person / Time | |
|---|---|
| Issue date: | 06/20/1989 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7 NUDOCS 8907060199 | |
| Download: ML20246A221 (77) | |
Text
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F UNITED STATES OF AMERICA NUCLEAR REG'ULATORY COMMIS SION 1
k6 BRIEFING ON THE APPLICATION OF THE SEVERE ACCIDENT POLICY TO THE LEAD APPLICATION FOR ADVANCED LIGHT WATER REACTORS LOCatiOD ROCKVILLF, MARYLAND 1
03I6l JUNE 20, 1989 l
Pages:
54 PAGES
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NEALR.GROSSANDCO.,INC.
COURT REPORTERS AND TRANSCRIBERS 1323 Rhode Island Avenue, Northwest Washington, D.C.
20005 (202) 234-4433 Iji 8907060199 890620 PDR 10CFR PT9.7 PDC
= - _.
- j s
O DISCLAIMER i
This is an unofficial transcript of a meeting of the United States Nuclear Regulatory Commission held on June 20, 1989, in the Commission's office at One White Flint
- North, Rockville, Maryland.
The meeting was j
i 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 7-.
informational purposes.
As provided br 10 CFR 9.103, it is not part of the formal or informal record of decision of the matters discussed.
Expressions of opinien 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 e
addressed to, any statement or argument contained herein, except as the Commission may authorize.
9 NEAL R. GROSS couar nemontras Ano inansemias 1S23 aHo0E I!!.AND AVR4Us, N.W.
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' 4 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION' i
I q
i BRIEFING ON THE APPLICATION OF THE SEVERE ACCIDENT POLICY TO THE LEAD APPLICATION FOR ADVANCED LIGHT WATER. REACTORS i
PUBLIC MEETING I
1 Nuclear Regulatory Commission
' l One White Flint North j
Rockville, Maryland l
I i
Tuesday, June 20, 1989 l
i The' Commission met in open session,... pursuant I
i to notice, at 10:00 a. m.,. Lando W.
- Zech, Jr.,
'l Chairman, presiding.
COMMISSIONERS PRESENT:
i LANDO W.
- ZECH, JR.,
Chairman of the Commission i
THOMAS M. ROBERTS, Commissioner l
KENNETH M. CARR, Commissioner KENNETH C.
ROGERS, Commissioner i
JAMES R. CURTISS, Commissioner F
6 NEAL R. GROSS i
COURT REPORTERS AND TRANSCRIBERS.
1323 RHODE ISLAND AVENUE, N.W.
(202)234 4433 WASHINGTON, D.C. 20005.
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STAFF-AND PRESENTERS' SEATED AT THE-COMMISSION TABLE:-
./
SAMUEL.J. CHILK,' Secretary WILLIAM C..PARLER, General' Counsel i-DR. THOMAS MURLEY LESTER RUBENSTEIN CHARLES MILLER THEMIS SPEIS JAMES-TAYLOR l
ASHOK THADANI DINO SCALETTI 4
ee e
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1 P-R-0-C-E-E-D-I-N-G-S 10:08 a.m.
2 CHAIRMAN ZECH:
Good morning, ladies and 3
gentlemen.
This morning the NRC staff will brief the 4
Commission on the application of the Commission's 5
Severe Accident Policy to the lead advance light water 6
reactor for design certification, General Electric's
~
7 advance boiling water reactor.
This is an information 8
briefing and no formal Commission vote is planned for 9
this meeting.
10 I understand thr.t copies of the slides to be 11 used.during the presentation are available as you 12 enter the meeting room.
13 Do any of my fellow Commissioners have any 14 comments before we begin?
15 Mr. Taylor, before we begin then, let me 16 welcome you and the staff and in particular note that 17 Mr. Rubenstein, who is here with us today, is going to 18 be retiring soon.
He'll be joining me.
And I know 19 that you've been very mindful of the public service of 20 trust and confidence that our country has placed in 21 you and the publi c service you've given after 30 22 years, I understand, and we want to specifically thank 23 you for that significant public service and for your 24 service to our agency and for our country.
25 MR. RUBENSTEIN:
Thank you, sir.
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CHAIRMAN ZECH:
Mr. Taylor, you may proceed.
2 MR. TAYLOR:
Good morning, sir.
Dr. Murley 3
will introduce the topic and the staff will then give 4
a detailed briefing.
1 i
I 5
CHAIRMAN ZECH:
Thank you very.much.
You 6
may proceed.
7 DR.
MURLEY:
Mr. Chairman, this briefing l
8 today, I think, represents a major step forward in the I
i 9
Commission's standardization policy.
We are l
10 essentially on the schedule that we established over 11 two years ago on the advanced boiling water reactor 12 and there have been three, I would say, significant 13 licensing hilestones during that period so far for the 14 ABWR, and this is the third.
15 The first one was the licensing review basis
.1 16 document.
This was issued in August of 1987.
It set l
l 17 the guidelines on how we, the staff, were going to I
18 review the application because we knew we were c-19 entering unchartered territory to some extent.
This i
1 20 was a GE initiative; they wanted such a licensing 21 review basis document.
We agreed with them and it has 22 held up very well.
It's guided the staff, I think, i
l 23 quite ' well the last two years.
We're encouraging 24 other applicants, as a matter of fact, to work with 4
v' 25 us on a licensing review basis document for their l
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i 1
5-4 4
1
.1 plants as well.
.)
2 The.second major licensing step was last i
i 3
January when we described to the Commission how the j
i 4
staff proposes to treat what I would. call traditional j
5-safety issues, like design basis accidents, fire 6
protection, technical specifications and those sorts 7
of things.
The staff and GE wera in agreement on
"]i
)
8 those issues.and we are proceeding on the. basis that' 9
we outlined for the Commission.
10 Today we're going to describe how the staff 11 proposee to handle severe accident, issues in the ABWR l
12 review.
This is a thorny issue, as you know, and i
13 rather tha'n let the issues bubble up to the top from 14 staff reviews, which has'been the traditional method 15 of review for new plants, we've tried.to d.efine the 16 policy issues early and develop resolutions.
And 17 that's what we're bringing to the Commission today for 18 discussion.
19 We've had many meetings with the staff.
.I 20 took my seni.rc staf f. out to San Jose in March for a 21 two day meeting where we discussed these issues and GE 22 and the staff are in general agreement on: the issues 23 we're going to discuss today.
There are still, of 24
- course, some design details that we have yet to 25 settle; things like leakage control system for MSIVs, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1325 RHODE ISLAND AVENUE. N.W.
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charcoal filter bit questions and those sorts of 2
things.
I do not regard those as major policy issues, 3
but rather the normal kinds of design details that the 4
staff reviews and settles.
So with. this policy 5
guidance in-- place, then the staf f-reviews can move 6
ahead over the next year.
7 Let me talk about schedules for a moment.
8 We expect to be able to issue what I would call final l
9 draft SER next spring.
We'll be issuing SER chapters 10 as we go along.
But this final draf t. would be 11 something that we would go to the ACRS with and expect 1
1 12 a letter from the ACRS.
We will be and have been 13 working With the ACRS all along, but prior to 14 beginning the hearing process, we would expect to have 15 this final draft next spring.
i 16 We would then put out a final SER - and an j
1 i
17 FDA, which is a final design approval, next summer.
1 18 With that in place, we would then begin.the hearing 19 process in late summer of 1990.
That hearing process l
20 would then, we expect, take about 14 months leading up 21 to certification of the ABWR in October of 1991.
That 22 has been the schedule that we've been adhering to and, 23 as I said, with these policies guidance in place we 24 see no impediment to meeting those schedule.
It, of
(-v 25 course, depends on GE sending the material to us on NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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time and it depends on no major diversions of the 2
staff.
Again, I don't see any problem with either of 3
those.
4 I
GE and others have spent some $250 million 5
on the design and development of the ABWR and the 6
design is in quite good shape and staff review can 7
proceed.
~
8 With that introduction then, Les Rubenstein 9
will discuss the severe accident guidelines that we've 10 worked out.
11 CHAIRMAN ZECH:
Thank you very much.
You 12 may proceed.
13 MR. RUBENSTEIN:
Good morning.
14 I'm going to start with the second view 15 graph.
The first view graph states the purpose of our 16 meeting, which the Chairman and Dr. Murley have both 17 stated quite directly.
And as Dr. Murley said, I'm 18 going to discuss some specific features of the ABWR 19 design and their relationship to severe accident 20 phenomena, 21 The topics of discussion are grouped into 22 three general parts.
The first grouping, station l
l 23 blackout, Intersystem LOCA and ATWAS, really deal with 24 phenomena which are substantial initiators of core tL 25 melt sequences.
And we'll discuss these specifically NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N W.
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1 1
in terms of the ABWR design features which address I
2 them and which, I
might
- say, address them 1
I 3
satisfactorily.
I 1
4 The second group deal with severe accident 5
phenomena, particularly as they affect containment 6
performance, design and the management of core debris
,l 7
and-core cooling -- pardon me, debris cooling.
i
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8 And the third list of items are some miscel-1 9
laneous subjects which will be prominent during the i
10 review and preparation of the final design approval
, l) l 11 and the design certification rulemaking itself.
l l
l 12 The second group on view graph three deal 1
h 13 with design goal for the containment and the plant 14
- itself, hydrogen control venting and core debris 15 coolability.
And as I said before, the miscellaneous l
16 groups range from source term through to BWR thermal-17 hydraulic stability.
I 18 If I might have the fourth view graph.
As 19 we've stated a couple of times this morning, we're 20 addressing the phenomena on a design specific basis.
21 And on the first group, the first item I'm going to 22 address is station blackout.
23 At the outset I would say that the design 24 goes beyond the station blackout rule and it is sized 25 such that the plant can be brought to a shutdown with NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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1 ono. train.
This in accomplished through three p
2 independent electrical divisions and three 100 percent l
I 3
capacity diesel generators.
In addition to the diesel
{
generators which deal with the design basis accidents, l
4 a
I
-5 there is also an alternate AC combustion turbine 6
generator to deal with the internal events and as a
'7 backup to the design basis emergency diesel 8
generators.
This is an oft-the-shelf type item with a 9
very quick start.
i 10 The station blackout ' design also has 11 robustness which is reflected in a ten hour blackout 12 period survivability during which period one can use 13 the RCIC a'nd station batteries.
And this would allow 14 one time to restore station power.
15 In the unlikely event that station power 16 were not restored, f.t also has an AC independent water 17 addition system which relies on fire protection
~ l 18 equipment.
.1 19 DR. MURLEY:
I should mention, Mr. Chairman, I
}
20 the RCIC is the reactor core isolation cooling system, 21 and that's the one you use when the isolation valves i
n 22 have bottled up the reactor and so you cool the core I
23 by - using water from the pool.
It's an' important l
)
24 safety system.
I 25 CHAIRMAN ZECH:
Yes.
Thank you.
NEAL R. GROSS-COURT REPORTERS AND TRANSCRIBERS h
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MR.
RUBENSTEIN:
Well, on the next view l
2
- graph, 5,
it's our conclusion regarding station j
f
{
3 blackout preliminary to final review the staff 4
believes that with these features we will have a l
1 5
sufficiently lower risk of station blackout compared 1
l 6
to the previous BWR designs.
7 If there's no question about station 8
blackout, I'll move along to the second phenomena 9
which the ABUR addresses on dealing with intersystem 10 LOCA.
Here there was clearly a need and a capability 11 of eliminating concern of a LOCA outside the 12 containment.
And the goal.was such that with high 13 confidence that the probability of an interfacing l
14 LOCA, which will lead to an unisolable LOCA outside of 15 containment was very low.
We wanted to fix this 16 problem, we wanted to make it go away through the 17 design and GE did this.
And to do that they put on a
~
18 testable capability for the ECCS in-board check valves 19 with position indication in the control room.
In 20 addition, the ABWR low pressure systems **e adequately 21 protected from reactor coolant system pressure.
This 22 means their design standards for the piping are such 23 that it would require a number of malfunctions before 24 the low pressure piping would see system pressure and 25
- they, in and of themselves, would be designed to--
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where
- 4. hey're tied to the primary system to be capable 2
of accommodating system pressure.
System pressure is 3
about 1,000 PSI.
4 With these features that the ABWR has, the 5
staff is confident that - the potential threat of an 6
intersystem LOCA is resolved for the ABWR.
~
7 Can I have view graph 7, please?
In regards 8
to the ATWS rule, 10 C.F.R. 50.62 the G.E.
design has
.k 1
9 a number of interesting features.
They've gone to 10 both hydraulic and electrical rod control run-ins.
_j 11 They have a recirculation pump trip capability.
12 They've done away'with the old SCRAM discharge volume 13 system whi'ch gave us quite a u't of trouble in years
)
l 14 past.
And they have a --
15 COMMISSIONER CARR:
Just out of curiosity, 16 how did they do that?
J
)
17 MR.
RUBENSTEIN:
- Well, they've gone 18 basically to the dual hydraulic, which is a water
-]
19 backed up nitrogen system and the mechanical system on i
20 live run-in.
21 COMMISSIONER CARR:
Okay.
I'll look into it i
22 further.
j 23 MR. RUBENSTEIN:
They have offered'a manual 24 standby liquid control system.
The ATWS rule' l
25 stipulates automatic.
.The staff has asked GE to do a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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reliability analysis to confirm acceptability.
And if i
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2 it is found acceptable, we will recommend an exemption
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from the ATWS rule for this.
Thus,.in effect, the 4
ATWS rule will be satisfied.
S-COMMISSIONER-ROGERS:
Well, will we set our I
6 own criteria for that acceptability?
1 7
MR. RUBENSTEIN:
We have not yet, but this 1
8 is early in the review part.
l 9
DR.
MURLEY:
I should add that we have 10 required and requested GE to submit a reliability 11 analysis to us.
That reliability analysis is to 1
12 justify that manual SLCS is acceptable.
Based on that 13 review, th'en that will be the basis that we agree-or l
14 disagree on.
We haven't yet accepted it.
l 15 CHAIRMAN ZECH:
Do we know that anyone has a 16 fully automatic standby liquid control system?
17 DR. MURLEY:
Well, the current designs now 18 are automatic and the maybe I'd better, before-I 19 get in too deep, let Ashok Thadani tell the details.
20 CHAIRMAN ZECH:
All right.
Fine.
Please i
i 21 identify yourself to the reporter, please?
22 MR. THADANI:
I'm Ashok Thadani, NRR staff.
23 There's only one plant today that has 24 automatic standby liquid control system, and that's 25 Limerick, Unit 1.
And the rule, the ATWS rule, did NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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not require automatic standby liquid control systems 2
for any plants except those that went into operation 3
after, I believe, it was 1986.
But I may be off on 4
the year.
5 And if I-might also address the other 6
question that was raised in terms of the SCRAM 7
discharge volume as to where the discharge goes, it 8
goes in the reactor vessel itself.
9 CHAIRMAN ZECH:
All right.
Thank you very 10 much.
11 MR.
RUBENSTEIN:
Moving on to view graph 12 number 8.
We're now getting into the second grouping 13 of design features, Moving from the initiators of core 14 melt sequences to some of the more containment 15 performance oriented design features.
16 As you may recall from our discussions with 17 you about the progress on EPRI and previously on
~
18 Genr' -! Eleu cic's design, that the EPRI requirements 19 document has a goal of ten to minus five core melt 20 frequency and it has a public safety goal for a 21 significhn: sf.te boundary release, that is an off-22 site dose release of 25 REM at a half mile of ten to 23 the minus six probability.
i 24 As Dr. Murley said, previously GE and the l
25 staff in the licensing review basis document also NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N W.
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-addressed a containment design goal of performance.
(.
2 And this was a conditional containment failure 3
probability of ten to the minus one over credible core 4
damage sequences.
5 These conditions apply to that-definition of 6
ten to the minus one.
We define containment failure 1
7 as an uncontrolled release of fission products from 8
the containment and we assume in the analysis, or 9
General Electric assumes that the sequence starts with 10 the onset of core damage.
In effect, we keep the 11 debris in the containment.
And with these three I
l 12 design goals resulting in these specific design ~
I l
13 features 6f the ABWR, that is design goals of ten to 14 the minus five core melt frequency, ten to the minus 15 one conditional containment failure probability and 16 ten to the minus six significant site boundary 17 release, we believe that the design offers a balanced 18 accident prevention and mitigation capability and will 19 achieve defense in depth for the plant.
So we've 20 dealt with the initiators of the accidents, the severe i
21 accidents.
We have a containment performance goal and 22 we have a value which is more conservative than the 23 health objectives of the safety goal.
24 So we believe with that driving some of the 25 design features of the containment and severe NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N W.
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accident, we have a balanced approach.
2 Specifically some specifics of near accident s
3 phenomena and the ABWR design features are hydrogen 4
control.
As you may recall from 10 C.F.R. Part 52 and 5
its predecessor 5034(f) that the design would have to 6
accommodate 100 percent metal water reaction and a 7
less than a 55 percent uniform hydrogen concentration.
8 Well, the ABWR design deals with this by inerting the 9
containment with a nitrogen atmosphere. In addition, i
10 it has a hydrogen recombiner capability.
And with 11 these features we believe that the hydrogen control 12 features of the ABWR design are acceptable.
'iew graph 10, please.
To provide 13 V
14 containment over pressure protection, that is 15 containment pressure integrity for the ABWR, General 16 Electric has proposed an additional feature which is a 17
" hardened" wetwell air space vent which would allow 18 venting to the stack at a controlled release rate and 19 would be emitted at an elevated value above the plant.
20 This vent operation would be AC independent.
21 That is, only direct current and pneumatic pressure 22 would be required for closure of the two vent valves 23 which are in series with the vent and which are 24 normally open.
It includes a rupture disk, which is 25 set slightly above the containment ultimate rupture NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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strength and the vent itself would allow a reasonable
(
2 amount of time to restore long term containment 3
cooling without major failure.
4 Some of the designs of this detail are still 5
being-worked out, but it would include something like 6
a 12 or 14 inch diameter piping.
7 COMMISSIONER CARR:
What controls the 8
release rate then?
A venturi, the size of the pipe 9
or--
10 MR. RUBENSTEIN:
Size of the pipe.
11 COMMISSIONER CARR:
Size of pipe.
12 DR. MURLEY:
Commissioner, we may still be 13 needing to' review some details on that.
For example, 14 I haven't seen what the release rate is, so it could 15
- very well be that you may want to put a venturi in the 16 line or something.
17 COMMISSIONER CARR:
Two valves and a rupture
~
18 disk doesn't give you a lot of control normally.
19 MR.
RUBENSTEIN:
However, it is sized to 20 take out about three percent decay and this 21 would be equivalent to 1RHR train.
22 Moving on to view graph 11, which is an item 23 in addition to hydrogen control, the containment over
'l 24 pressure protection, which the ABWR design addresses, 25 is core debris coolability.
The suppression pool is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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I 17 1
physically between the debris, which would be in a 2
lowered dry well, and the containment liner.
And this 3
would deal with the containment liner degradation 4
problem.
In effect, it would provide a physical 5
barrier between the lower dry well and the liner.
6 In addition, the design is also constructed 7
in such a way to enhance core debris coolability.
It
)
8 has a passive lower dry well flooding capability, 9
which is provided by fusible plugs between the 10 suppression pool and the lower dry well.
We don't 11 have all the details on this, but it would be 12 something where between five and ten roughly four inch 13 plugs which would melt at about 500 degrees fahrenheit 14 and provide water from the suppression pool and flood l
15 the lower dry well.
l 1
1 16 In addition to provide limiting suppression l
17 pool fission product bypass, if the vessel did melt 18 through and in that unlikely event, there would be a l
19 controlled pathway for the debris.
It basically 20 assumes that the water quenches the debris and would 21 provide some fission product scrubbing capability.
It 22 would also cool the gases and to make sure that 23 there's no back flow, the vents would be covered by 24 water throughout the course of the accident.
Some of 25 these details await further study and discussion with NEAL R. GRO$S COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N.W.
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the staff.
But on view graph 12 we come to the 2
conclusion that we really do not expect containment s
3 failure by melt through of the base mat or the liner.
4 There's a fair amount of work to be done on 5
some of the details of this, but we're optimistic that 6
it will work out in a positive way.
7 Now, getting into the third grouping of more 8
miscellaneous items, as regards the source term and 9
considerations, we're really dealing with two separate 10 applications of source term.
The first one was with 11 our normal Part 100 citing requirements and the second 12 one how we're going to calculate the GE or the EPRI l
13 large release safety goal.
i 14 In the case of the first one, the licensing 15 basis continues to be 10 C.F.R. Part 100 citing i
i 16 criteria with its associated source term as they're l
17 represented in TID 14844.
Now, to meet this GE needs 18 a little credit for certain design features which are 19 under discussion with the staff.
Dr. Murley mentioned 20 those before, it's the MSIV leakage.
They need 21 probably 140 or 150 standard cubic feet per hour.
22 This is in contrast to maybe 11 1/2 standard cubic 23 feet per hour in the Tech specs.
They need some 24 credit for steam line condenser hold up fission 25 products and for in containment iodine removal.
And NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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we're optimistic that in discussions with the staff 2
that these proposals will be acceptable.
3 Now, for the more realistic source term that 4
they will use to demonstrate that they meet their 5
safety goal, the 25-REM 1/2 mile one in a million 6
probability of exceedance, we would consider
~
7 departures from the assumptions of Part 100 and allow 8
a realistic assumptions regarding fission product 9
behavior. And --
10 COMMISSIONER CARR:
More realistic means 11 more realistic than we're using.
J l
12 MR.
RUBENSTEIN:
Well, best estimate and j
1 13 calculations and hold up and much more database in f
14
- f. arms of particulate matter, stuff like that.
1 15 COMMISSIONER CARR:
So it's a departure from i
16 the licensing basis then?
17 MR. RUBENSTEIN:
Yes, it clearly is, sir.
~
18 COMMISSIONER CURTISS:
Why are we using--
19 in January the staff apprised us that you were 20 concerned with the licensing basis and it wasn't 21 consistent with the current knowledge that we have, 22 TID 14844 This looks to be the first time where the 23 staff is proposing to use a source term for licensing 24 basis that essentially reflects old knowledge and a 25 different source term for evaluating beyond DBA type NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N W.
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20 1-activities or safety goal compliance.
2 I guess I have two questions.
One, if there 3
is, in fact, more realistic information, more accurate 4
information that we've acquired in the source term i
5 that is reflected-in the source term code package,.why l
l 6
don't we use that across the board for both 'DBA and 7
severe accident?
And two, if ' not, what's the basis 8'
for using two different source terms?
I 9
DR.
MURLEY:
I think I can address that, j
i 10 Commissioner.
The answer is actually fairly simple.
11 That is, we would have to have a rule change to' change i
12 the source term.
And we embarked on that path some 13 years ago'and we found, in fact, in order to support 14 the type of certainty that we'd need for a rule 15
- change, there was not uniform agreement in the 16 technical and scientific community.
And so we do not 17 have a revised rule that takes into account all the 18 most recent data with general agreement in the 19 scientific community.
20 COMMISSIONER ROBERTS:
Isn't that still an 21 objective?
22 DR. MURLEY:
Yes. 'But we thought we'd --
23 COMMIS SIONER' ' ROBERTS : -
-I understand.
I 24 understand.
25 DR. MURLEY:
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1 21 1
way this time.
- Rather than delay all of our
~
2 standardization activities until we can get a rule
}
3 change, we decided to move ahead this way.
We believe l
4 it is not a penalty, a big penalty for the design.
5 And so we're moving ahead with Part 100 with TID 14844 6
source term for the citing licensing basis.
7 COMMISSIONER CURTISS:
It's not clear to me "l
i 8
whether you're saying that we'are using the existing i
9 TID for licensing basis because there isn't the q
10 consensus necessary.
support a rule change or to l
11 whether there's some other reason that has lead to 12 that response.
13 DR.
MURLEY:
- Well, we know it's 14 conservative.
15 COMMISSIONER CURTISS:
Remember,.the design 16 certification itself.is going to be a rulemaking.
17 DR. MURLEY:
Yes.
18 COMMISSIONER CURTISS:
It won't amend the.
1 19 current rule, but if it's a procedural question as to i
20 the defensibility of-that change in rulemaking, we are 21 using a new source term in'the context of a rulemaking 22 to certify the GE ABWR.
23 DR.
MURLEY:
Yes.
What we're doing, l
24 Commissioner, is we 'll be using the old standard, 25 tried and trua, TID 14844 source term, which we are NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUF, N W.
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23 1
confident is conservative for citing purposes.
- Now, 2
there is another criterion which is not one of our 3
regulations.
It is an industry criterion, which is 4
that the dose during an accident, the dose at a half 5
mile from the plant should be no more than 25 REM 6
whole body with a probability of ten to the minus 7
sixth per reactor year.
I got that correct?
8 MR. RUBENSTEIN:
Yes, it is.
9 DR.
MURLEY:
- Now, that is not our 10 regulation, but it's their criterion and we've more or 11 less, adopted it as, yes, that's a good criterion to be 12 using.
It is that criterion where we will discuss.
13 with GE and with the industry more realistic source 14 terms.
I 15
- Now, insofar as it's a basis, I haven't 16 thought about that, whether it becomes a part of the 17 basis upon which we license the plant and therefore
~
18 becomes part of the rule itself?
I guess we'd have to 19 chat with somebody from the General Counsel's office.
20 COMMISSIONER CURTISS:
I guess I'm touching 21 on a procedural question.
It's an issue of timing or 22 legal defensibility, narrow concern with rulemaking 23 that seems to me that we've got a rulemaking here 24 underway or contemplated culminating in 1990 or
'91 25 that will, in fact result in use of the new source NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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~
23 9
1 term information for evaluating this plant.
I don't 2
disagree that the current source term information is s
3 tried and true, or maybe put a little more accurately, 4
it's tried and not quite true.
It's not consistent 5
with the current knowledge is the question I have.
6 I'm not disagreeing with the use of the source term 7
for beyond DBA type activities in thic context.
My 8
only question is, is'there also a basis given what the 9
staff has said in January about the inconsistency of 10 the current source term with current knowledge for 11 applying that same realistic source term uniformly for 12 DBA and beyond DBA?
13 bR. MURLEY:
Now it's one thing to say that, 14 namely that current knowledge has shown that the old 15 source term is conservative.
But it's another thing 16 to have something firm to take its place and can 17 withstand rulemaking.
We faced up to that some years
~
18 ago and we concluded that the science was not in place 19 to support a rulemaking.
Now, whether we have 20 concluded dif f erer.tly today, I don't know that we 21 have.
Would Themis Speis would like to answer this?
22 COMMISSIONER CURTISS:
We have for severe 23 accidents, in this context.
24 MR.
SPEIS:
- Yes, I would like to add one 25 thing; that even though we're using the same source NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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)
24 1
term as far as.the source term that you introduce into ys 2
the containment, you know, the 25 percent iodine, we 3
have made two changes within the design basis of the-
]
4 LOCA which current information supports.
And those 5-changes involve the credit that you give to the 6
suppression pool for cleaning up some fission products
- I 7
and also to the behavior of iodine insofar as this' 8
praise in PWR.
So we have moved, even though we have l
l l
9 moved slowly, but we still have moved in some areas 1
10 within the design base.
11 COMMISSIONER CURTISS:
I'd like to pursue, 12 but I won't hold up the briefing.
Why don't we go 13 ahead.
14 COMMISSIONER CARR:
When do you expect the.
l I
data to begin change the source term, bring it up to 1
15 l
16 dats?
i l
i 17 COMMISSIONER CURTISS:
That's my point, it's
~j 18 in now for severe accidents.
That's - what this paper 19 is saying.
20 MS.
SPEIS:
- See, the source term is a 21 complicated issue because it's tied to containment 22 performance.
For example, the source term that has 23 been used now, the 25 percent iodine, is'not far out 24 of line if you have early containment f ailure.
So 25 it's a very complication that it's tied to-the whole NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N.W.
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25 1
severe accident issue.
It's a conflict of how we 2
close severe accident issue and then we have to go 3
back and see what changes we make to the source term 4
which addresses the design bacia type of 5
considerations.
6 COMMISSIONER CURTISS:
- Well, there are 7
severe --
l 8
COMMISSIONER CARR:
If that was an answer to l
l 9
my question, I missed it.
i 10 COMMISSIONER CURTISS:
- Well, there are 11 severe accident considerations that in new Reg 1150 12 need to be resolved, Commissioner.
But from what I 13 understand', the source term code package, that part of 14 new Reg 1150 is essentially complete and gives us 15 enough confidence to say that for advanced reactors in 16 the severe accident arena we have sufficient 17 information that will in turn have to be defended in 18 the context of a rulemaking to use that source term 19 information.
What I am pressing you all to address is 20 the question of whether if all of that is true, and 21 recognizing the complexities that new Reg 1150 poses 22 for that purpose, isn't it also true that source term, 23 that that source term revision could equally well be 24 used for DBA considerations, design basis, licensing 25 basis?
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Since I don't want to pursue it here, it is
(~
2 a question I have about --
s 3
MR. TAYLOR:
I think we may write up a paper 4
and address this for you.
Why don't we do that?
5 DR. MURLEY:
I think the Commission needs a 6
separate briefing on the source term thing.
But I 7
don't want to leave the impression that we're very 8
close to having a uniform agreement on a new source 9
term for licensing, because I don't think we are.
I 10 personally have not seen what's in 1150, for example, 11 and I don't think many on my staff, if any, have 12 either.
So I'd certainly want to take a look at that.
13 I think it' deserves a special -- we'll do that.
14 MR.
RUBENSTEIN:
I would add in another 15 dimension in terms of the ABWR and the severe accident 16 source term, that's a propose'd industrial investment 17 protection public safety goal ten to the minus six and
~
18 it is substantively more stringent than our own health 19 objectives of the safety goal.
So while we haven't 20 adopted that in any sense as a requirement we have, in 21 effect, said you propose this, we're very interested 22 and see how you meet this goal yourself.
We've had 23 discussions with all the vendor designers in EPRI l
24 regarding this and we're not ready to adopt it, nor l
25 should we probably adopt it as a requirement.
So in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RQDE ISLAND AVENUE, N.W.
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i i
that kind of a discussion where you know you have a j
2 substantial amount of margin over our requirements, it J
3 makes the dialogue on severe accident source term 4
features more relaxed.
I 5
CHAIRMAN ZECH:
Can we proceed?
l 6
MR.
RUBENSTEIN:
View graph 15, as the
/
l 7
Commissioners may remember, 10 C.F.R. 52 required that 8
all future plants do a probabilistic risk assessment.
9 This would include both internal and external events l
10 in the PRA.
And in addition to that requirement, in 11 discussions with General Electric and the other 12 members of industry, we have also asked that they j
13 provide a' reliability and maintenance criteria to l
14 ensure that the as-built design and the assumptions I
15 regarding the components and systems used in the PRA 16 be maintained throughout the life of the plant.
17 They're addressing this and it's a very difficult 18 question.
GE and NUMARC are addressing it, perhaps, 19 on a different schedule and at the same time with each 20 other and they're working on it.
So I can't really 21 say much more about this at this time, except that we 22 find it's important throughout the life of the plant 23 to make sure that the key assumptions and commitments 24 of the PRA are maintained.
25 COMMISSIONER ROGERS:
How were you assessing NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE (SLAND AVENUE. N.W.
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28 1
that and reviewing that i
. PRA?
Are we doing that
]
]
2 currently ourselves or using contractors?
3 MR. RUBENSTEIN:
Research has got the main
.j l
4 review force and they're using Brookhaven National 5
Labs.
6 COMMISSIONER CARR:
When does GE say they're j
7 going to provide the reliability of maintenance
.?
8 criteria?
9 MR. RUBENSTEIN:
Do you have a date on that?'
10 CHAIRMAN ZECH:
Well, wait a minute now.
11 tiould you care to step to the microphone and' identify
)
12 yourself for the reporter so we can hear your answer, l
13 please?
Thank you.
14 MR.
SCALETTI:
My name is Dino Scaletti.
1 15 I'm with the NRR staff.
16 We don't have a date for the submittal yet.
17 We expect it to come in sometime in early 1990 --
~..
18 CHAIRMAN ZECH:
Thank you very much.
19 MR. SCALETTI:
which it will be in well 20 before the certification begins.
21 CHAIRMAN ZECH:- Thank you.
22 COMMISSIONER CURTISS:
Just a quick question 23 on that subject of maintenance.
24 CHAIRMAN ZECH:
Yes, proceed.
25 COMMISSIONER CURTISS:
I take it what's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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_ = _ _ _ _.
_ _ ~ - -
'I 29 i
i 1
envisioned here is that the Japanese. into this 2
initiative will lead to a plant that meets all the-2 3
requirements that we think are important and address 1
4 all the issues that we think are important and, 5
conversely, the U.S.-version of this plant will. do the.
6 same.
The Japanese, as I think we all have seen.and 7
known, require their plants to. shut down every three 8
months for a periodic required maintenance period.-
9 Two questions.
One, do they intend to apply'
~
10 that regulatory regime to this1 plant?
And two,.is-
,l 11 that something that we are.considering as an important 12 and essential regulatory ingredient of the approved i
13 process of'ABWR7 J
l 14 DR. MURLEY:
liet me try to answer.
We met i
15
- with the regulatory. authorities in Japan.
And my 16 understanding is that they do intend. to follow: the
. :. 1 17 same regulatory criteria for the advanced BWR as they
)
18 do for their current plants, which would mean that 19 there be a period of every year where they shut down 20 for a f ew -months and carry : out.certain defined 21 maintenance activities.
They go,. of -course, further 22 than we do by quite a bit.
They tear down their1 23 turbines every year as-well-as 'certain other.
24 equipment.
25 We are not considering that as a
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- - - _ = _ - _ = _ = _ =
30 well, I guess I
'1; requirement.
I think we're not 2
shouldn't go much further than that.
It's not clear 3
to us that that is required, as a' matter of fact, for 4
good maintenance.
It may be possible that their 5
preventive maintenance goes too far in terms of--
6 beyond what's required.
And I think they're thinking-7 that themselves, although they. haven't changed to back 8
off a bit because they don't know how far to back off.
9 But in private discussions, they think that maybe-10 tearing down the turbine every year is not required 11 for every instance.
12 But to answer your question, directly, they 13 are s till ' planning, to the best of my knowledge, to 14 adopt those same criteria for this plant and, no, we l
l l
15 are not considering that.
I iil 16 COMMISSIONER CURTISS: '
In that respect, the 17 two initiatives are not complete technical parallels.
18 There are some differences in the requirements that 19 they would impose, perhaps, on the significant issue' i
20 depending upon how you view the significance of
]
l 21 mandatory outages for maintenance.
22 DR. MURLEY:
Yes.
The design -- whether it j
23 has an impact back in. design, that -is whether the i
24 Japanese maintenance rules and requirements would 4
1 25 impact the design such that the design of'the Japanese I
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.u-.
+
A
31 1
plant, the Rashuwazaki plant, is different from ours, 2
I don't know.
s 3
COMMISSIONER CURTISS:
Okay.
4 CHAIRMAN ZECH:
All right. Let's proceed, 5
-please.
6 MR. RUBENSTEIN:
And finally, in the set of 7
miscellaneous items that we have, we' have the BWR
~
8 thermal-hydraulic stability, the staff believes that 9
the design eliminates the need for operator action and 10 reduces the potential for exceeding fuel damage 11 limits.
This is accomplished by vent operation in the 12 region of least stability being prevented and selected 13 control ro'd run-in initiated by trip of at least two 14 reactor internal pumps.
15 COMMISSIONER CARR:
Is that an 16 administrative prevention in the first one?
17 MR. RUBENSTEIN:
Yes, primarily.
You have 18 to stay out of that section in the power flow mode.
19 That concludes the specific ABWR design 20 featuras and if you have no more --
21 DR. MURLEY:
Let me just make sure that this 22 last one is understood.
This would preclude, we 23 believe, the type of event that heppened at LaSalle in 24 1987.
So it's relatively easy to design out and they I
25 believe they have done it.
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d 13 2 4
1 CHAIRMAN ZECH:
All right.
We'll proceed.
2 DR.
MURLEY:-
We'll move on to the j
J 3
conclusions then, Mr. Chairman, that the GE and the 4
NRC staff are in agreement with the approach that j
5 we've just.- described to you on these severe accident 6
issues.
The staff believes that its review will l
7-confirm th'e effectiveness of these f eatures.in
]
1 1
8 addressing severe accident goals that are defined'in l
9 10 C.F.R. Part 52 and Commission's policy papers.
10 If the review does, in fact, confirm the
,3 J
11 effectiveness, then the severe accident ' closure will i
12 be achieved for the ABWR.
I regard this as highly-
)
1 4
13-significan't that more than a year before we are to
)
14 enter into the hearing process for certification,. we 1
15 will have reviewed and settled and agreed, at least on q
16 the broad outlines, of the policies associated with i
17 severe accidents.
And'with these policy guidelines in
~I 18 place, then the staff review can move ahead on the 19 details and I think be much more effective.
20 Of
- course, the staff will inform the j
21 Commission if an;* additional requirements arise that 22 are necessary to resolve severe accident concerns.
We 23 do not see any on the horizon, but there may be some-t 24 that do arise.
25 That concludes our briefing.
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33 l
1 CHAIRMAN ZECH:
All right.
Thank you very j
2 much.
3 Any questions from my fellow commissioners?
ll 4
Commissioner Roberts?
l 1
l 5
COMMISSIONER ROBERTS:
There is an advanced j
6 BWR being built in Japan now?
7 DR. MURLEY:
That's right. I should have 8
mentioned, Mr. Chairman, there.are plans for two units 9
at the Kashuwazaki site.
Their licensing review and-2 10 regulatory review is moving in parallel with ours and 11 we are working very closely with them, with the-1 l
i 12 authorities in Japan.
J i
13 Their schedule is that construction will 14 begin in February of 1991.
They plan to pour the 15 basemat in July of 1992 and begin commercial operation 16 in 1996.
There will be two units..
The second unit 17 will follow beyond the first unit a little. bit.
18 COMMISSIONER ROBERTS:
Well' at this stage 19 will those units essentially be what you've described 20 this morning?
21 DR. MURLEY:
Yes.
22 COMMISSIONER. ROBERTS :
I know there's some 23 unresolved less important issues.
24 MR. RUBENSTEIN:
It's ersentiallv yes except 25 for a couple of minor things like turbine orientation NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISt.AND AVENUE, N.W.
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34 i
1 and how they inject water into the core.
That's'the 2
essential major change.
1 3
DR.
MURLEY:
The major features that we 4
described oday, the severe accident ' f eatures, my S
understanding is.will be in those. plants.
)
6-MR. RUBENSTEIN:
It's a joint design between i
i 7
General Electric, Tobashia.and Hatachi.
'-l 1
i 8
CHAIRMAN ZECH:
Commissioner Carr?
)
9 COMMISSIONER CARR:
On the equipment that's 10 required to mitigate the severe accident not being 11 safety related, if that's going to run a long time and 12 take care of its intended function,.isn't it, in 13 effect, going to be safety related?
Won't you have EQ 14 requirements and power supply requirements and 15 earthquake requirements if it's really designed - to 16 handle the severe accident?-
17 DR.
MURLEY:
- Well, the intention, Mr.
18 Commissioner, was that we not require these features 19 for low probability events to be what I call gold 20
- plated, namely meet all the seismic requirement,
)
21 single failure proof requirements and so forth that
)
22 your first line safety systems would have to meet.
We 1
23 didn't really see the need for that.
'I 24 The short answer' to your question is no we.
25 don't see them becoming --
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35 1
COMMISSIONER CARR:
I guess my curiosity is 2
if you don't need them when you need them, then you 3
probably don't need them at all?
I mean, I can't 4
imagine having to rely on that piece of equipment.
I 5
guess what I'm really trying to figure out is why 6
require it at e 3 'i you don't require it, do you?
7 Are you saying you don't require it you don't 8
require the equipment?
9 DR. MURLEY:
We're requiring it in the sense i
10 that the equipment is -- we expect it to be there.
We 11 don't expect that it has the same kind of reliability 12 that we want, for example, for emergency cooling 13 systems and that sort of thing.
14 COMMISSIONER CARR:
I read that e.s you want 15 it to be there, but you don't expect it to ever be 16 used?
17 DR. MURLEY:
We don't expect it to be used, l
18 no.
But that, nonetheless, making it single failure 19 proof and gold plating it does not necessary it 20 adds a lot to the cost we know.
We don't know that it 21 adds all that much to its reliability.
22 COMMISSIONER CARR:
I'm not talking about 23 single failure proof.
I'm just talking about having 24 to be used in a long time in a tough environment and--
25 DR. MURLEY:
Let me ask Mr. Thadani to speak NEAL R. GROSS COURT REPORTERS ANDTRANSCRIBERS 1323 RHODE ISLAND AVENUE, N W.
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.36' 1-
'to this because there are some details.
,~
2 COMMISSIONER CARR:
Fine.
3 MR. THADANI:
Again Ashok Thadani.
4 Commissioner, the intent is clearly that the 5
equipment such as the vent or the fusible plugs or 6
various features.to deal, with severe accidents,.the 7
intent clearly.is that they'be able to perform their 8
functions in the environment that they'are expectedLto.
9 see.
That demonstration should. be provided.
But 10 beyond that, there are many 'other requirements of 11 safety grade systems that would have really no impact 12 for the kinds of conditions and situations we're 13 discussing'.
14 Dr. Murley pointed to single failure proof 15
- consideration, which would require two. of the same 16
- things, so to speak.
It would be :one example.
17 Another example you mentioned in the seismic.
If the 18 system were required to mitigate - some accident 19 scenario for seismic events, then that - would be an 20 element in itself because of the very fact that it had 21-to perform its function in that environment.
- However, 22 if a severe accident comes about because of combina-4 23 tions of f ailures' from internal events, then this l
24 system would not be designed to those strict seismic 25 standards and that's really the top process that went NEAL R. GROSS COURT REPORTERS ANDTRANECRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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i 37 j
J 1
into saying they don't have.to be safety grade.
2 COMMISSIONER CARR:
Okay.
All right.
I 3
CHAIRMAN ZECH:
Commissioner Rogers?
4 COMMISSIONER ROGERS:
I understand that you 1
l 5
intend to address compliance with the ABWR severe.
6 accident requirements on a design specific banis 7
rather than through generic rulemaking for certain i
l 8
practical reasons; to minimize scheduling impacts and I
9 such.
And what assurance do we have on the Commission
]
i 10 that as each issue gets resolved on a design specific 11 basis that we're not drifting into some kind of j
12 difference in requirements for different advance J
13 reactor designs?
14 DR. MURLEY:
Let me-try to answer that..
15 You're correct, Commissioner, it's primarily for 16 scheduling reasons that we're approaching this.
But 17 many of the issues would be the same.
Of course, i
i 18 hydrogen control will be the same for -- we'll have to 19 address that issue for other plants.
ATWS we will 20 have to address, 21 As we go through the review process, it 22 could very well be that other designs choose to meet 23 the severe accident issue in another way.
For example 24 GE has chosen and we've agreed with it, I mean we've 25 kind of encouraged it, that they have over pressure NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N.W.
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__-_______a_-
-a 38 9
1 protection by a vent.
It could be that other plants 2
may decide that they can maintain containment 3
integrity without a vent, and we'll have to review 4
that.
5 So, I guess what I'm saying is that. the 6
bas'ic requirement, I think, will stay pretty much the 7
same but how the individual designs choose to meet the 8
requirements may differ as we move through.
Now, I 9
recognize 'this will lead to different certified 10 designs and because the certification is, in itself, a 11 rulemaking, in essence we will have different rules in 12 place that meets the severe accident issue.
13 I do not see that personally as a major 14
<trawback and problem. I think the staff can maintain a j
y 15 consistency in'the sense that the basic requirement'to
]
l 16 address ATWS, to address hydrogen, to address the l
17 issues is still there.
'I 18 COMMISSIONER CURTISS:
What you're saying 19 is, do you view the design certification rulemaking as 20 a vehicle strictly to ensure that the applicant l
21 complies with existing requirements that are, in turn, l
22 generic in nature and set forth in other parts of the 23 regulations or and to set forth any design specific 24 requirements that might be necessary for individual 25 applications?
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.]7 4
39 j
1 DR. MURLEY:
Well, I would say both.
That
)
I 2
we expect that the design that goes through j
3 certification will meet all the regulations that are i
'1 4.
on the books for severe accidents unless, of course, 5
there's some feature where we decide to give -- where 6
they get an exemption.
We mentioned one today on the l
7 ATWS rule.
There may be some cases like that if we an
- 1 l
i 8
agree with them that their reliability is good enough, 9
then there may be some narrow areas of exemptions.
10 But we do expect them to meet the current regulations 4
11 and we also expect them to meet the severe accident i
12 issues that we've defined that go beyond our current 13 regulation's.
l 14 COMMISSIONER CURTISS:
I guess it's the 15
- converse of that that I'm concerned'about.
I - didn ' t.
16 mean to interrupt you.
.]
17 DR. MURLEY:
No, that's fine.
i 18 COMMISSIONER CURTISS:
It's worth pursuing 19 because I did, I guess, see that as the most.
j i
20 significant policy question in this paper, the 21 decision to change course really 180 degrees from the 22 recommendation last September in 88-248 to pursue 23 severe accident issues in a rulemaking and now, and-
']
1 24 for what I thought were a number of very good reasons.
j i
25 to do that, and now with very little discussion a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N W.
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,1 decision that I thinkLis probably the most'significant'
(/
this paper,: and that is to pursue severe 2
one. in i
3 accident in the context of -individual design 1
4-certification step-in addition to the. concern ' that 5
Commission Rogers has about-the potential f or :
. 4 6
proliferation ofldifferent' requirements for different 7
' plants, Les' leaves and somebody comes on board and you 8
get into that design specific review process.
9 I
guess I.' m-also concerned that the 10 potential exists f or ' the'- design. certification 11 rulemaking'to.do one of two things.- one, to establish' 12 a general generic policy that the' Commission really is 13 effective 1~y saying we're going to apply-to all these.
14 Source term is a good example of that.
One of the 15 reasons I'm concerned about what the staff has-16 proposed on source term, differing treatment,.or the 17 design certification ' becomes the vehicle for making 18 what amount to generic changes-in existing regulatory 19 requirements.
And the one there that occurs'to me'is 20 the relationship = of the operating basis serving with 21 the SSE that was addressed in the last briefing where 22 it looks to me like for the GE plant they.'re going to-23 decouple those two in a' manner that effectively omits 24 Part 100.
That's my concern ' ai - we say that we're i
U 25 going to approach these issues on a design specific' s
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basis when, in fact, the issues themselves for both 2
DBA and severe accident may well be generic in nature.
3 DR. MURLEY:
I share your concern that we 4
could -- it is possible to drift apart and I think the 5
way to prevent that is close oversight by the 6
Commission as well as close oversight by the staff.
I 7
get back to it, it's an issue of timing.
I wished we 8
had a severe accident rule, you know, five years or so 9
ago.
But we don't, we don't have it and it would be l
10 enormously disruptive now to the reviews that have 11 been going underway to stop and to develop a severe 1
12 accident rule.
It could be done.
I mean, to me it's 13 clearly a ' policy question for the Commission. But we 14 are on the path of reviewing these on design specific 15 basis and we're going to do everything we can.
And we 16 think we can keep them consistent.
17 COMMISSIONER ROGERS:
Well, I had hoped that 18 you would bring to the attention of the Commission any 19 decisions of that sort, you know, as a package or 20 however, not necessarily one by one, so that we're 21 aware of those as they come up.
And from our point of 22 view, we'll have an opportunity to ask that question 23 again from time-to-time.
24 DR. MURLEY:
I think we can do that on a 25 regular basis.
We ought to plan on doing that, yes.
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42 1
COMMISSIONER ROGERS:
'Just somewhat along 2
these lines, have the safety enhancements that General' s
3 Electric has offered in their design, ' are they also 4
reflected in the EPRI advanced light water reactor 5
requirements document or do they exceed-the 6
specifications in that guide?
7 DR..MURLEY:
In1some cases they exceed them, 8
in other cases they meet them.
For example, the one 9
' in the area of' electrical systems to cope with station 10 blackout, the ALWR requirements document requires an 11 alternate AC combustion turbine generator, which I i
12 think the early design of the ABWR did not have, but 13 they decided to. agree with it and put it in.
So in 14 that sense it meets those requirements.
15 In other areas, for example in hydrogen, the c
16 ABWR essen'ially side steps the issue because they've 17 gone to inerted containments.
And we're having 18 discussions -- I'm having a meeting yet this week with 19 EPRI on what should be the design basis for hydrogen 20 for containments and that there's some -- well we're 21 having disagreements at the staff-level, at least, on-1 22 what that should be.
23 But in a sense, the ABWR goes beyond that 24 requirement.
They have installed a vent to protect
(.J 25 for over pressure.
That goes beyond the-ALWR NEAL R. GROSS COURT. REPORTERS AND TRANSCRIBERS
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requirements document.
1-2 COMMISSIONER ROGERS:
Well, are we staying 3
in touch with EPRI as we sort of come to decisions on 4
these matters so that they have an opportunity - to 5
incorporate them back in their documents?
6 DR. MURLEY:
Yes, we are.
This does not set 7
a precedent-or a
requirement for the EPRI 1
8 requirements.
In fact,.some areas they disagree that
]
9 this has gone too far.
So we're still discussing with 1
10 them what should be the ALWR requirements.
11 COMMISSIONER ROGERS:
- Well, I'm just-12 concerned about that they're aware of these?
l 13 DR. MURLEY:
Oh, yes.
Oh,. we're in very 14 close contact with.them.
15 COMMISSIONER ROGERS:
They can decide 16 however they want, but at least they should have.the l
17 information as to what our position is.
j f
18 MR. RUBENSTEIN:
19 subcommittee in Palo Alto about a month ago and we 20 went over these very specifically and they had an 21 opportunity to make their case and, as Dr. Murley 1
22 said, that they don't necessarily agree with some of I
23 the offerings or our decisions and we're going to meet-24 with them again on Thursday.
l 1
25 COMMISSIONER CARR:
All right. Good.
Good.
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MR. MILLER:
Commissioner Rogers?
2 COMMISSIONER ROGERS:
Yes.
3 MR. MILLER:
requirements or state to us where they differ so in 5
the review process we are acutely aware -of where the 6
differences occur.
Where the differences do not l
7 occur, they are in conformance and agreement with the 8
rest of the requirements.
l 9
CHAIRMAN ZECH:
Commissioner Curtiss?
10 COMMISSIONER CURTISS:
Let me just close the 11 loop on the question that Commissioner Rogers has 12 raised, because I do think it is a significant one and 13 this decision will say a lot about how we review 14 design certification in the future, how we treat 15 issues like severe accident and DBA issues.
I guess I 16 remain to be convinced based upon the rather brief 17 discussion in this paper that rulemaking is not the
~
18 way to go.
The staff has talked about the concerns 19 with the schedule, but what I would like to see in 20 more detail, particular in view of the detailed 21 discussion in 88-248 and the two workshops that have 22 been held and the considerable discussion that's gone 23 on, I'd like to see from the staff a more detailed 24 discussion of just what the schedule impacts would be.
25 The original schedule called for a 17 month v
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45
'o' 1
rulemaking, proposed to final in a manner that, at 2
least in September, the staff knew to be compatible l
3 with the schedule for review of design certifications.
4 And I guess I'd question what has changed since 5
September of last year and June of this year in terms 6
of a reversal of the position on that.
7
- Secondly, there were benefits that were 8
identified at that time in 88-248 to proceeding by 9
rulemaking, from a legal standpoint, from the 10
. standpoint of uniformity which Commissioner Rogers has 11 touched upon and from the standpoint of fleshing out 12 the requirements of the safety goal and severe
~
i 13 accident policy statements.
And I guess I'd like to 14 reserve judgment on the wisdom of the course that the 15
- staff has proposed, albeit in an information paper 16 here to see that kind c' discussion and discuss the 17 pros and cons at this point' and if there is a sound 18 schedule reason for while we can't proceed, be 19 convinced of that as well.
20 7 do have some particular questions.
Source 21 term I've already discussed and I gather we'll be 22 having more detail come in on that.
23 Just some loose ends that I'll tie up.
Has 24 the ACRS reviewed this paper?
What's the status of 25 that?
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'I i
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MR.
RUBENSTEIN:
Yes, they have.
We met-2
- with them just about a week.ago.
It was not. involved i
3 opportunity to review it.
We proposed that they may 4
want to consider giving comments and I believe that i
5 they decided because of the early nature of the review j
i 6
with the design, that they would not give comments.at
]
)
1 7
this time.
I 8
COMMISSIONER CURTISS:
.The question on that-9 is really sort of a tangential question.
The ACRS has 10 been tasked to develop containment criteria.
Can you I
i 11 explain to me how the ACRS initiative relates to what
-(
l 12 you've got going on here and in other contexts?
13 f(R. SPEIS:
They had a task force in trying 14 to address this issue.
Basically the issue is whether q
'i 15 we should have a containment criteria that encompasses j
l 16 both design base accidents / severe accidents. And as
- . j 17 you heard from the staff today, our approach is kind l
1 18 of truncated.
You know, we go forward with design 19 base accidentu and then we add margin to make sure 20 that we accommodate the severe accident concerns.
And 21 the ACRS, you know, when we talk to them they said, 22 "Well, that makes sense, but maybe it's more
.i. t 23 makes more sense to do it in a more global way, to 24 come up with precise criteria," because right now the 25 containment criteria, for example, are those that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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47 d
1 1
derive from LOCA from steam line breaks and pressures
)
.J i.
2 in the temperatures.
And then we'll see if we can add 3
margin to the containment to accommodate augmented 4
pressures and temperatures from severe accidents and 5.
the ACRS says, "You know, maybe we-should come up with 1
l 6
one pressure and tempere.ture to globally consider both j
l
- l 7
design basis and severe accidents."-
8 I'm sorry I drug out the one issue.
9 COMMISSIONER CURTISS:
Well, I guess the s
10 question that I have is it appears to me that there's j
i 11 some potential for conflict.
You all, I take it, have 12 made the decision that this plant could be licensed
~
13 with hardened vent 45 PSI and the size of the wetwell i
14 volume that you've got.
Where are we if the ACRS I
15 comes in and says we ought to have 60 PSI, we 16 shouldn't have a hardened vent mass reactor, we should l
17 have a larger wetwell volume?
Where are ;with this 18 initiative at that point?
19 MR.-SPEIS:
I don't feel what we're talking 20 with the ACRS will effect that basically.
And as I j
21 said earlier, the ACRS didn't see anything wrong with 22 what we're doing, but they wanted to study this some
-l
.I 23 more and --
l 24 DR.
MURLEY:
Excuse me.
But a direct 25 answer, though, Mr. Commissioner, is if they come in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVEN'JE, N.W.
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48 1
with.a f undamental. dif f erence like that it will
.c wind up at this table, I'm sure, the i
2 ultimately 3
Commissioner's.
But we'll do our:best to work with' 4
them to accommodate their concerns and so forth.. But 5
if there is a fundamental design change like that, 6
then it could well wind up with the Commission.
7 COMMISSIONER CURTISS:-
Okay.
One final' 8
question.
On the performance criteria that GE has set
~
9 out to meet here, do you have any feel _for whether-you 10 think they can meet those when external events are 11 factored, given the. numbers that we're seeing on 12 external events?
13 MR.
RUBENSTEIN:
We've seen. some very 14 preliminary numbers and we've only had the PRA for 15 about a month'no" and just taking from a presentation 16 that they gave us, we believe they can.
17 COMMISSIONER CURTISS:
Okay.
18 DR. MURLEY:
But I think until we see the' 19 details, we can't answer that for sure, j
20 MR. RUBENSTEIN:
Again, it's a summary table l'
21 and the summary table clearly showed that it met it 22 with the over pressure protection capability.
23 COMMISSIONER CURTISS:
Okay.
That's all I 24 have.
25 CHAIRMAN ZECH:
Well, it does seem to me NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE, N.W.
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49 1
)
1 that a paper on the status of the source term work 1
2 would probably be appropriate, as we mentioned earlier 3
in the meeting.
And perhaps after that paper comes to 4
the Commission, the Commission wou?d like to consider
.i a
5 a meeting to discuss it.
1 I
6 DR. MURLEY:
Yes, sir.
I 7
CHAIRMAN ZECH:
And frankly, I agree with 8
the staff's approach toward the severe accident in i
1 9
this ABWR design and'I commend the staff on their work 1
J 10 towards certification of an advanced light water i
11 reactor.
I'd also commend General Electric - Company 1
12 for their leadership role in bringing forth the lead 13 advanced light water reactor design for certification.
14 I agree with my colleagues that it would be 15 important to try to bring forth the convergence of the 1
l 16 generic rulemaking on severe accidents at the 17 appropriate time to realize the full. benefits of 18 standardization. I think that's the right the thing to l
19 do. On the other hand, I really do believe that the 1
1 20 efforts can be done in parallel and that we can 21 continue with your efforts along the ABWR-22 certification process and not stop the progress you've 23 made.
I think that would be a mistake, personally, to 24 do that.
But I do agree that we should do what we can 25 to work towards a rulemaking.
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I personally feel that what you're doing in 2
the ABWR effort could really contribute to a better 3
rulemaking.
It would give us experience to work in 4
this area mindful of the plant specific requirements 5
of this design would also I don't think they need 6
be incompatible with what we'd want to do for a 7
generic rulemaking.
So it seems to me that you should 8
continue to do what you're doing as regards this 9
certification process and certainly not hold it up, 10 thct would be my approach, and wait for generic 11 rulemaking.
12 Generic rulemaking, of course, as we all 13 know would have been nice to have in place right now.
14 We don't have it in place.
I don't think it 15 doesn't wouldn't bother me, though, to go in a 16 parallel effort in this regard recognizing that we do 17 eventually want to get to a generic rulemaking that 18 would, again, realize the fu]1 benefits of the Part 52 19 effort that we've made and standardization program and 20 so forth.
But I would certainly recommend that the 21 Commission not bring a halt to this very important 22 effort that really is the lead effort towards a 23 certified design and, as far as nuclear energy and our 24 country for the future is concerned, it has to be i
25 viewed upon as a very important effort.
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51 1
COMMISSIONER CURTISS:
Let me add I agree 2
with what the Chairman has said.
I di-dn't mean to 3
leave the impression that I think we ought to in any 4
way slow down this effort.
I think the schedule that 5
you have adhered to is a-remarkable testament to the 6
close work that you've undertaken and the commitment 7
of the staff and I really is one of the few
~
8 instances where the schedule's really stuck as we've 9
had each of our individual briefings.
And I want to 10 commend you all for that.
11 I do think the Chairman's suggestion to take 12 a look at the parallel effort with an objective--
13 having a ' severe accident rulemaking of a generic 14 nature would address a number of the concerns that I 15 have and is a sound suggestion.
16 MR.
TAYLOR:
Mr. Chairman, the staff is 17 discussing actively in this evolutionary phase based 18 upon our current regulations and then these changes 19 like in the ABWR being sure our current regulations 20 are revised if necessary, cleaned up for the 21 evolutionary designs.
Then we're talking about what i
22 about the advanced light water reactor and so on.
So l
23 the staff is in parallel with this effort to take this l
24 design that GE has worked up concerning with bringing 25 the rulemaking efforts in parallel.
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52' j
1 CHAIRMAN ZECH: ; Good.
I think it's'--
']
-2 MR.
TAYLOR:
To struggle.with. this both--
-3 there 's' some.. things that should be changed and we've 1
4 talked about that with.the commission.
So-we are not d
5
-- we continue to' be. conscience of - the necessity ~ to 1
6 get our rules' updated.
l
'l 7
CHAIRMAN ZECH:
Good.
.Well,, I think it's-
- I important that'we continue that effort.
8 1'
9 MR. TAYLOR:
'And. the~ advanced light water 10 reactor designs will be-a whole dif f erent~ approach. -
_j 11.
We're very happy to see this treatment-of severe tl 12 accident since we're struggling with the existing 1
'I 13 plants on'that, and that's-the ---GE'has.done'a'very l
~
14 fine' job, as you have ' said, trying. to. address' these j;
15 issues.
'l 1
16 CHAIRMAN.ZECH:
All right.
Thank you.
)
17 Well,. I do think - it 's importantl that you 18 continue that effort.
19
- Well, let me thank the staff for this 20 important briefing today on the status of application l-21 of the severe accident policy to the standard plant'-
22 design.
As the staff knows, the Commission is very l
23 supportive of the standardization ' initiatives and 24 strongly supports your work in this area.
Advanced l
25 boiling water reactor along with the other advanced l
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design that we're aware that are underway are all very 2
important initiatives as they directly relate to the 3
future use of nuclear power in our country.
I'd 4
encourage the staff to continue to work closely with 5
all of the vendors of these advanced designs and to 6
address and resolve as best you can all the technical 7
and safety issues that are so important to the 8
certification process and to the mission of our 9
agency.
Many of them involve the severe accident 10 issues and challenges that we've talked about here 11 today.
It's important that we continue work in that 12
- area, I Delieve, in order to ensure that these 13 advanced designs are the best that can be designed 14 using the experience we have in these many years of 15
- operation of commercial nuclear power plants in our 16 country.
17 So I'd also encourage the staff to continue 18 to keep the Commission advised in the review of these 19 new applications and the criteria that are so very 20 important to the eventual, perhaps, approval and 21 licensing process that could be foreseen in the 22 future.
23 We do need to evaluate the generic nature of 24 all the issues and I appreciate the fact that you're 25 continuing to work in a parallel effort in that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVENUE. N.W.
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54-1 regard.
2 But thank you very much for a very important 3
briefing and for your efforts that you've made towards 4
providing really a future for nuclear energy in our 5
country in these advanced designs and the 6
certification process that you're working on so hard 7
and so effectively.
~
8 Are there any other questions or comments by 9
my fellow Commissioners?
If not, thank you very much i
l 10 for an excellent briefing.
i l
11 We stand adjourned.
l 12 (Whereupon, at 11:32 a.m.,
the public l
13 hearing wa's adjourned.)
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~..
a.
CERTIFICATE OF TRANSCRIBER This is to certify thatsthe attached events of a meeting of the United States Nuclear Regulatory Commission entitled:
TITLE OF MEETING: BRIEFING ON THE APPLICATION OF THE SEVERE ACCIDENT POLICY TO THE LEAD APPLICATION FOR ADVANCED LIGHT WATER REnCTORS PLACE OF MEETIpG: ROCKVILLE, MARYLAND DATE OF MEETING:
JUNE 20, 1989 were transcribed by me. I further certify that said transcription is accurate and complete, to the best of my ability, and that the-l transcript is a true and accurate record of.the foregoing events.
f!
(NLb
_ C L-:__
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r-v v
Reporter's name:
Miles Anderson i
l l
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PURPOSE--
,1 IC INFORM THE COMMISSION OF CERTAIN FEATURES OF GENERAL' ELECTRIC'S'ABWR THAT STAFF BELIEVES ~WILL ENHANCE SAFETY Af!D WILL SATISFACTORILY ADDRESS SEVERE ACCIDENT CONCERNS' UFON COMPLETION OF:THE-STAFF'S' d
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- HYDROGEN CONTROL
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STATION BLACK 0UT DESIGF GOES'BEYOND STATIcN BLACKOUT 1 RULE THREE INDEPENDENT' ELECTRICAL DIVISIONS THFEE 100% CAPACITY DIESEL 16ENERATORS
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ABhis PROVIDES SIGNIFICANTLY LOWER I'iSV FROM STATION BLACKOUT COMPARED To PREVICUS BWR DESIGNS i
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IF MANUAL SLCS Is ACCEPTABLE, THE STAFF NILL RECOMMEND AN EXEMPTION FROM ATWS RULE 1
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SOURCE TERM LICENSING BASIS CONTINUES TO BE-10 CFR PART 100 SITING CRITERIA WITH ITS ASSOCIATED SOURCE. TERM'(TID.14844)
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SCllRCE TERM:(CONT'D)!
MORE REALISTIC SOURCE TERM TO BE USED' L
TO DEMONSTRATE GE SAFETY GOAL CAN BE ATTAINED
-' SAFETY G0AL:
PROBABILITY OF 0FFSITE DOSE 25 REM BEYOND 1/2 MILE FROM REACT 0P 1
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- I PROBABILISTIC RISK ASSESSMENT-(PRA)
- LEVEL-3 INTERNAL / EXTERNAL EVENTS PRA
- GE To PROVIDE RELIABILITY AND 1
MAINTENANCE CRITERIA To ENSURE I
l iHAT AS-BUILT DESIGN DESCRIPED BY-l CERTIFIED DESIGN.IS MAINTAINED.
APPLICATION TO INCLUDE KEY. ASSUMPTIONS 1
l AND COMMITMENTS OF PRA VG-15 I
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MiR THERMAL-HYDRAULIC STABILITY PLANT OPERATION IN REGION OF LEAST STABILITY PREVENTED SELECTED CONTROL rod RUN-IN INITIATED UPat TRIP OF AT LEAST Two REACTOR INTEF.NAL PUMPS DESIGH ELIMINATES THE NEED FOR OPERATOR ACTION AND REDUCES POTENTIAL FOR EXCEEDING FUEL DAMAGE LIMITS VG-16 0
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CONCLUSIONS
- GE Al?D STAFF IN AGREEMENT HITH APPROACH TO SEVERE ACCIDENT CONCERNS.
- STAFF BELIEVES ITS REVIEW WILL. CONFIRM EFFECTIVENESS OF THESE FEATURES IN' l
ADDRESSING SEVERE ACCIDENT GOALS-DEFINED IN 10 CFR PART 52 AND THE C0rMIsSIct!'s. POLICY PAPERS VG-17 e
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i 20NCLUSIONS (c0NT'D)
- IF EFFECTIVEf4ESS IS CONFIRMED, SEVERE ACCIDEllT CLOSURE WILL BE ACHIEVED FOR THE ABWR
- STAFF WILL INFORM COMMISSION IF ADD'l REQUIREMENTS NECESSARY To RESOLVE SEVERE ACCIDENT CONCERNS VG-18
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TRANSMITTAL. TO:
Document Control Desk, 016 Phillips
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ADVANCED COPY TO:
The Public Document Room
$/A N
DATE:
FROM:
SECY Correspondence & Records Branch j:
~
Attached are copies of a Commission meeting transcript and related meeting document (s). They are being forwarded ~for entry on the Daily Accession List and placement in the Public Document Room. No other distribution is requested or
.l required.
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Meeting
Title:
[
Aca a'84(s&hhu W 1
Meeting Date:
6/Ro /f6 Open /
Closed 1:
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ll Item Description *:
Copies ll Advanced DCS-
- 8 ji-to PDR-
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- 9 l l d
- 1. TRANSCRIPT 1
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- PDR is advanced one copy of each document, two of each SECY. paper.
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C&R Branch files the original transcript, with attachments, without SECY j;1.
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papers.-
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