ML20246K272
| ML20246K272 | |
| Person / Time | |
|---|---|
| Issue date: | 05/11/1989 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| ACRS-T-1738, NUDOCS 8905180017 | |
| Download: ML20246K272 (160) | |
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UNITED STATES NUCLEAR REGULATORY COhDdISSION In the Matter of:
SUBCOMMITTEE 0N ADVANCED BOILING WATER REACTORS OPEN SESSION l
Lo I
i Pages: 272-428/455 P1(C.Iosed sessim istcLue epges VA9 ~W$,
l ce: !!ethesda, Maryland Date: May 11,1989
________________________ g g. g.gh( M h u}jt h __.
HERITAGE REPORTING CORPORATION O
OficialReporters 1220 L Street, N.W., Suite 600 Washington, D.C. 20005 (202) 62M g905130017 890511 PD CR5 PDC
272
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1 UNITED STATES NUCLEAR REGULATORY COMMISSION 2
ADVISORY, COMMITTEE ON REACTOR SAFEGUARDS 3
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In the Matter of:
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4
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5 SUBCOMMITTEE ON ADVANCED
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OPEN SESSION BOILING WATER REACTORS
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6
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7
- Thursday, May 11, 1989 8
Room P-110 9
7920 Norfolk Avenue Bethesda, Maryland 10 The above-entitled matter came on for hearing, 11 pursuant to notice, at 8:30 a.m.
12 BEFORE:
MR. CARLYLE MICHELSON
\\
13 Retired Principal Nuclear Engineer Tennessee Valley Authority
-14 Knoxville, Tennessee and Retired Director, Office for 15 Analysis and Evaluation of Operational
- Data, U.S.
Nuclear Regulatory 16 Commission, Washington, D.C.
17 ACRS MEMBERS PRESENT:
18 MR. CHARLES WYLIE Retired Chief Engineer 19 Electrical Division I
Duke Power Company 20 Charlotte, North Carolina 21 MR. DAVID A.
WARD Research Manager on Special Assignment 22 E.
I.
du Pont de Nemours & Company Savannah River Laboratory 23 Aiken, South Carolina
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24 ACRS COGNIZANT STAFF MEMBER:
25 H.
Alderman HERITAGE REPORTING CORPORATION -- (202)628-4888 l
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NRC STAFF PRESENTERS:
(j 2
L. Rubenstein 3
4 5
6 7
8 9
10 11 12 13 14 15 16 27 18 19 20 21 I
22 23 l
24 l.
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PROCEEDINGS 2
CHAIRMAN MICHELSON:
The meeting will now come to
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3-order.
4 Today's meeting is a continuation of the review of I
5 the General Electric advanced boiling water reactors as
)
6 announced yesterday.
7 I am Carl Michelson, Subcommittee Chairman.
Other 8
members in attendance today are Charlie Wylie, David Ward, and 9
the staff representative is Herman Alderman on my right.
10 Due to unforeseen circumstances, a portion of 11 today's meeting will be closed to public attendance in order 12 to discuss proprietary material.
The closed session will be 13 at the end of each, will be at the end of.today.
We regret 14 the inconvenience to the public attendees at this meeting.
15 Do any of the Subcommittee members have any 16 comments before we proceed?
17 Seeing none, we will proceed with the revised 18 agenda, which I believe calls for rad protection as the first 19 item this morning.
Mr. Sawyer?
20 MR. SAWYER:
Good morning.
I'm Craig Sawyer 21 representing General Electric Company.
I am going to be 22 covering Chapter 12, radiation protection, plus a number of 23 other topics later in the morning.
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24 Just to give you an overview of what is in Chapter 25 12, it is broken into four sections; 12.1 talks about ALARA HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 considerations; 12.2 presents the source terms that are used f
2 to the various radiological analyses; 12.3 discusses radiation 3
protection throughout the plant; and 12.4 is dose assessment.
4 For purposes of today's discussion, I am basically 5
going to give you an overview of what is contained in those 6
various sections, and the status of where we are.
7 12.1 is ALARA.
One of the very beneficial things I 8
think that we have put together in the ABWR is the Japanese 9
experience with regard to maintenance and dose reduction 10 practices.
l 11 With our partners in Japan, we did a lot of studies l
l 12 of plant arrangements considering maintenance requirements and i
O l
U 13 what systems we needed, what the experience base has been on l
11 4 those systems with regard to maintenance, what can we 15 automate, what can we eliminate?
How can we change the 16 technical specifications from a point of view of making the 1
l 17 surveillance and maintenance more tractable?
So all of these 18 things were factored into the arrangement design, and, and i
19 including where necessary, putting the plant into smaller 1
20 packages, which were isolated from each other, to produce 21 cross-system contamination.
22 As you probably remember from the arrangement of the 23 plant, it is divided into clean zones and radiation potential
()
24 contaminated zones.
All this was done from the point of view 25 of trying to minimize the exposure to the operators.
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To give you a view of what the numerical J
2 quantification of our studies leads to, in 12.4 I have listed 3
on this chart the primary factors that have gone into what we 4
believe will be a substantial man-rem reduction for the 5
operation staff for the ABWR.
6 The use of internal recirculation pumps, of course, 7.
is a primary input in reducing the drywell radiation due both 8
to reduction in the pump maintenance itself, and because of 9
the large piping reduction reducing the, basically the 10 environmental dose rates within the drywell.
11 The use of the fine motion control rod drives 12 changes the amount of maintenance required on those drives, 13 and how the maintenance is to be done, so the, there is a 14 significant reduction in, in man-rem coming from that aspect.
15 We have automated a number of things, including the 16 fuel handling and inspection which reduce basically the time 17 that people have to spend in radiation zones.
18 We have paid a lot of attention to improving the 19 water quality and taking advantage of the best technology 20 available in the use of materials to reduce basically the 21 radiation levels from crud and other deposition on piping, and 22 as you have heard yesterday, the rad waste system is automated 23 to some extent to reduce also the need for personnel, and
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24 leads to lower radiation levels as well.
25 (Slide)
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1 MR. SAWYER:
In a moment, I'm, when I get to 12.4, I 2
will show you what the results of our evaluations have 3
. yielded.
j 4
12.2 is the source terms.
This is a chapter, some 5
of which has been submitted, some of which is still in 6
process.
7 The neutron sources area is complete, has been 8
submitted to the staff for review.
The analysis review is 9
basically two-dimensional transport theories as the basis for 10 calculating the fast neutron doses and as well as thermal 11 neutron doses of the critical places in the plant.
The other 12 source terms are in the process of being completed, will be 13 submitted very soon to the staff for their review, but at this 14 time, they are not complete.
15 (Slide) 16.
MR. SAWYER:
In 12.3, basically the purpose of 12.3 17 is to give the radiation maps for the plant for basically the 18 reactor building and the rad waste building, the control 19 building, and the turbine building for various 20 conditions--normal operation, refueling, design basis 21 accidents.
22 The reactor building normal operation is complete, 23 has been submitted to the staff for review.
The others are in
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24 process and will be submitted very shortly, but they are not I
25 available for review just yet, i
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(Slide) 2 MR. SAWYER:
The dose assessment basically follows 3
more from 12.1 than from the other two sections, and we talked 4
about features that the ABWR has in a summary way that lead us 5
to believe that the man-rem that the operators will be exposed 6
to will be a lot lower.
Let me give you some background on 7
some of the bases we use for doing our dose assessment.
8 As you are aware, the Swedish, most of the Swedish-9 BWRs are based on using internal pumps, and so--and using fine 10 motion drive similar to those that we are planning to use, so 11 we were able to derive from their operating experience what we 12 expect to see in the way of, of radiation levels, and also we f
13 derived a lot of information with regard to maintenance 14 requirements for those new features that the ABWR has.
15 By way of comparison, in 1984, the average U.S.
BWR 16 for a number of reasons was achieving exposures that 17 approached a thousand man-rem per plant per year.
Japan is at 18 about half of that value, including the entire BWR fleet, and l
19 Sweden at about a hundred man-rem.
l I
20 Since 1984, the Japanese experience with the new BWR 21 5 models which were going on line in Japan has been extremely 22 good.
You have probably read news releases that are 23 reporting, started reporting numbers first just below a
()
24 hundred man-rem per year down to where recently the first l
l 25 Kashiwazaki unit which has been installed reported the first 1
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cycle radiation maintenance number in the teens.
I forgot i
2 exactly what it was, but it was less than 20 man-rem.
1 3
Now of course, that's first cycle experience, and j
4 you expect some growth from that, but it is, it represents a 5
dramatic downward trend from where we have been in the past.
6 We are quite pleased with that experience because a lot of the 7
choices that we have made--use of hollow fiber filters, the 8
use of, minimum use of cobalt containing steels, and such 9
things--are all being factored into the ABWR as well, and of 10 course, the new features that we are putting in the ABWR give 11 us increased confidence that the Japanese experience on their 12 BWR Ss will be matched or exceeded in the case of the ABWR.
13 In fact, we have committed to meeting the goal of a hundred 14 man-rem per year for U.S.
application of the ABWR as part of 15 the EPRI requirements program.
16 MR. WYLIE:
Is there any attempt to break down the 17 type of radiation or do you have any feeling for it, that it 18 is gamma, beta?
19 MR. SAWYER:
It is mostly gamma.
This chart is a 20 pretty busy chart.
21 (Slide) 22 MR. SAWYER:
And I apologize for that.
The actual
'3 dose assessment in 12.4 hasn't been formally submitted, but O
24 the etert nee eexea the Guestsea. ema this ted1e renre emte 25 the response to that question, and this will be formalized in i
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1 our 12.4 submittal, but what I have got here is by plant area v
2 and by equipment type, what, what the typical BWR in the U,S.
3 now sees in the way of manhours spent per year, and 4
accumulated man-rem per year, and what-we anticipate the ABWR 5
will see for the two, for the two things, and to simplify the 6
comment section, what we have done is we have footnoted it and 7
binned it into one of five possible bins for what, the major 8
reasons for the reduction, whether it is reduced radiation and 9
no recirculation lines, improved maintenance procedures, use 10 of fewar components which require maintenance, reduced 11 radiation levels because of improved fuels, water chemistry, 12 or materials, and finally, automation.
<m 13 And if you go through and do the arithmetic, you 14 will find that the reductions in man-rem occur both because of 15 reduced hours spent and also because of reduced radiation 16 levels, and as you can see, the current average in BWRs is now 17 getting down to where the Japanese were in 1984, and for the 18 ABWR, we are slightly under the goal that we set for ourselves 19 for U.S.
application, and as I said, the sanity check on this 20 is, is that there are several BWRs of the current vintage in 21 Japan which are well under a hundred, and the latest one 22 being, as I said, even in under 20 for their current 23 experience, so that's, in summary fashion, gives you a capsule
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24 view of what is in Chapter 12 and what is going to be in 25 Chapter 12.
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1 Are there any questions?
If not, I think I'll pass 2
on to the next topic.
3 MR. WARD:
I do have one.
I'm trying to figure out 4
from this what part of the dose reduction is due to fuel 5
quality improvements or just maintaining the reactor coolant 6
at a lower level.
7 Is there something specifically attributed to that?
8 MR. SAWYER:
Well, basically the way the numbers 9
were arrived at is if you are interested, I can probably get 10 for you specifically the quantification of the reduced, the 11 reduced radiation from, from the leakers and what it 12 contributes to the, to the water soluble dose itself, as
(
13 opposed to the dose which is played out, dose from crud, but 14 both are considered here.
15 Offhand, I don't remember how much is due to each, 16 I suspect that it is mostly the latter from crud because we 17 have been--for a number of years now, even the U.S. experience 18 has been pretty good with regard to fuel contamination.
19 MR. WARD:
Okay.
But it is just the high doses in 20 U.S.
plants are just crud left over?
21 MR. SAWYER:
That is certainly true from the newer 22 plants.
Some of the older plants out there still have 23 residual contamination because of fuel, from leaking fuel in
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24 the earlier days.
It takes a while to clean it up, but most 25 of the U.S.
numbers currently that contribute to that 450 HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 number come from crud if it is, if that, you know, if it is 2
that area.
3 MR. WARD:
Thank you.
4 CHAIRMAN MICHELSON:
Do these numbers reflect the 5
possibility of hydrogen water chemistry?
6 MR. SAWYER:
They certainly do.
They take credit 7
for that.
8 CHAIRMAN MICHELSON: 'They don't take credit?
9 MR. SAWYER:
When we estimate the, basically ther 10 the radiation that we expect to see in the, in the zone, 11 coming from piping, and we worry about what that, that the 12 radiation level is, the experience that we have used to
(
13 estimate the radiation comes from plants that have adopted 14 hydrogen water chemistry.
15 CHAIRMAN MICHELSON:
Okay.
There is extra shielding 16 I guess already in the design?
17 MR. SAWYER:
To account for it, yns.
18 CHAIRMAN MICHELSON:
Okay.
19 MR, SAWYER:
Of course, most of these numbers come, 20 most of these numbers come during maintenance anyway, so the 21 shielding that you are talking about comes from the 16 man-rem 22 that you observe during operation.
23 CHAIRMAN MICHELSON:
That would, that could be more
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24 easily controlled by--
25 MR. SAWYER:
Right.
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1 CHAIRMAN MICHELSON:
Controlling the excess; 2
controlling the excess, as I understand the hydrogen water 3
. chemistry, is something you can turn on and off at will so to 4
speak, but the provisions will be in there, and I guess it is 5
not clear to me whether the actual equipment be in the design 6
also or just the provision that you could design and install 7.
it later.
8 MR. SAWYER:
Not equipment will be in.
We have 9
committed to hydrogen water chemistry, absolutely.
10 CHAIRMAN MICHELSON:
Okay.
Thank you.
11 MR. WARD:
So the lower doses, I mean you are 12 showing lower, the radiation effect from hydrogen water 13 chemistry in the turbine building doses, is that right?
14 MR. SAWYER:
The increase, if you are concerned 15 about not, the additional nitrogen 16, that dose level that 16 happens at power because of the use of hydrogen water 17 chemistry, that shows up in work at power.
The others are 18 basically work during shutdown.
19 MR. WARD:
Oh, okay.
I 20 CHAIRMAN MICHELSON:
Is there anything in the 21 material specifications to encourage the use of low cobalt 22 materials?
23 MR. SAWYER:
Yes, sir.
That's part of--
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24 CHAIRMAN MICHELSON:
That is reflected in here, too, l
25 I guess?
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1 MR. SAWYER:
That's part of our material l
2 requirements.
l 3
CHAIRMAN MICHELSON:
Well, in the case of valves, 4
for instance, what are you using as substitutes for present 5
hard facings?
6 MR. SAWYER:
Sorry, I don't know the answer to that, 7
but I know that we have a material specification that's paid a 8
lot of attention to using, basically either eliminate
,9 completely or as low as possible the cobalt contents.
There 10 is an actual number, but I don't remember what it is offhand.
11 CHAIRMAN MICHELSON:
But there apparently are 12 reasonable substitutes to, or at least better materials that 7
13 have less tendency to or less cobalt or less tendency to break 14 it off?
15 MR. SAWYER:
Right.
16 CHAIRMAN MICHELSON:
Okay.
Why don't we proceed to 17 the next subject?
18 11R. QUIRK:
Craig, the next two items are yours as 19 well.
The first item is GE position on containment 20 overpressure protection, the 30 minutes, to followed by break, 21 and then after break, we talk about severe accident design 22 features of EPRI ABWR.
23 Now I think it is your intent, Craig, to cover these
()
24 two topics in one, in one session?
25 MR. SAWYER:
That's correct.
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,MR.-QUIRK:
If it gets too long and we need to take 2
a break, that's fine.
.3-CHAIRMAN MICHELSON:
I think we are'doing pretty.
al -
well.
We are probably half an hour ahead of schedule'right 5
now.
6 MR.. SAWYER:
I think the schedule allocationcfor the 7
various topics today have been quite generous, so--
8 CHAIRMAN MICHELSON:
Just take whatever time you
.9 need, andLwhen you get tired whenever, we will take a break.
10 MR.' QUIRK:
I would like to precede Craig's remarks 11 with a reminder that the next, that the next Subcommittee 12 meeting, we will talk in detail on the PRA, GE's PRA, which is k
13 proprietary, and I have asked Dr. Sawyer to summarize and give 14 the bottom line of PRA and GE's philosophy on containment vent f
15 and overpressure protection in a non-proprietary way.
I think i
16 it is a topic that is of general interest and importance and 17 should be handled in a non-proprietary way.
18 CHAIRMAN MICHELSON:
But you are saying you will l
19 give us a summary of the PRA today?
20 MR. QUIRK:
Overview.
21 CHAIRMAN MICHELSON:
That's great then.
It will 22 help us in reading it.
23 MR. QUIRK:
However, I wanted to caution you a
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24 little bit.
It's always important to dive in and go for the 25 details, and if that happens, we have the option to answer the HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 question'in the closed session or to defor it until the next 2
meeting.
3 CHAIRMAN MICHELSON:
Sure.
I think an overview of 4
it now would be helpful just because, if we get into the depth 5
next time, then it is very helpful.
As I understand it, we 6
actually have it now.
I just haven't recognized that it is--
7 MR. SAWYER:
Nineteen.
8 MR. MICHELSON:
It's in two volumes, 19 1 and 2?
9 MR. QUIRK:
Yes, sir.
10 MR. SAWYER:
Okay.
So I guess--
11 MR. WARD:
We have the internal events part of the 12 PRA.
13 CHAIRMAN MICHELSON:
I guess why I didn't recognize 14 it is I was looking for something bir to come in, and it isn't 15 very big.
16 MR. WARD:
Five foot shelf, yes!
17 CHAIRMAN MICHELSON:
It's--but that doesn't mean it 18 isn't good.
It just means it isn't quite what I was watching 19 for, and didn't recognize it when it came.
20 MR. QUIRK:
If you want a big one, put the two 21 volumes together!
22 CHAIRMAN MICHELSON:
No.
I much prefer a smaller 23 one.
Let's you see what it is.
I'm sure it's going to take
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24 some time in itself.
We will have to keep that in mind on 25 that next Subcommittee meeting because a PRA of that sort, to HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 get into it at all, will probably take three, four hours.
x-2 MR. SAWYER:
I think you are right.
)
3 MR. QUIRK:
It is a substantial PRA.
It's done on a 4
standard plant, which is kind of unique, and it is enveloped 1
5 and I think we have. learned some things from the PRA and are I
l 6
going to discuss some features contemplating and discussing 7
what the staff has given us.
8 CHAIRMAN MICHELSON:
I am just wondering, for the 9
benefit of the Subcommittee whether we should entertain the 10 PRA on our own, or ask the PRA Subcommittee to look at it?
t 11 We could do it either way, of course.
12 MR. WARD:
Maybe we ought to combine it.
()
13 MR. MICHELSON:
We ought to at least appraise them 14 of the fact and ask them and make it a combined one.
That 15 obligates them to do something about it.
We will look at the 16 scheduling that particular day when we deal with the PRA so 17 probably we will have a joint meeting with the PRA 18 Subcommittee and they will also take a hard look at it 19 because we are kind of thin on this Subcommittee to be 20 looking at PRAs with all the other material.
I 21 MR. QUIRK:
Well, we would welcome a joint session 1
l 22 for the overview.
23 CHAIRMAN MICHELSON:
I'm sure they will be
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24 interested anyway, so Herman, when we schedule the next 25 meeting, I think that's the one in as I recall November or HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 something?
Does that sound right?
2 MR. QUIRK:
Sounds right,.yes.
l L3 '
CHAIRMAN MICHELSON:
At that time when we are going 4
.to get into the PRA in depth, and what we, the Subcommittee 5
would like to do is schedule a joint meeting with the PRA Subcommittee for that particular day in which we deal 7
strictly with the-PRA.
8 MR. QUIRK:
Perhaps that could be done in August or 9
September.
10 CHAIRMAN MICHELSON:
Well, it could be, but it is 11 not--we have got the SCR to do in August for the Chapters 4, 12 5,
6 and 15.1, and that's quite a, that's a full piece of work
(
13 by itself to focus on.
14 MR. QUIRK:
What I was thinking of, if you are going 15 to rely on the PRA Subcommittee, perhaps, you know, we could 16 go ahead with them in August.
17-CHAIRMAN MICHELSON:
Well, it is the same people.
18 MR. QUIRK:
I see.
19 CHAIRMAN MICHELSON:
It is just that it picks up a 20 few more people, 21 MR. QUIRK:
I see.
Okay.
l 22 MR. SCALETTI:
The August meeting is going to be an 23 extra meeting anyway.
The staff is willing to, if the ACRS
()
24 is, to put another meeting in.
If you--we don't object to 25
- that, i
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CHAIRMAN MICHELSON:
Do you think you would be ready U/
2 in August to get into the PRA?
3 MR. SAWYER:
Yes, from our point of view we would 4
be.
5 CHAIRMAN MICHELSON:
I am asking the staff because I 6
don't know where your review is.
I don't want to hit it too 7
early or too late.
8 MR. SCALETTI:
I don't think we would be ready by 9
that time to give staff conclusion.
We may be getting close, 10 but I wouldn't count on it for PRA substitution.
11 CHAIRMAN MICHELSON:
Why don't we just kind of leave 12 it open?
The fact is we may have a separate PRA joint meeting
(
13 along in September, October or something just to get that item 14 out of the way.
They may want more than one meeting on it.
I 15 don't know.
I will just have to see how they feel.
For our 16 purposes, I would prefer it only be one shot at it, but again, 17 we have to see how, how much--
18 MR. QUIRK:
Anticipating that, I think you are 19 right.
I would encourage you to see if we could fit it in in 20 August so we could have time.
21 CHAIRMAN MICHELSON:
The staff said they wouldn't 22 quite be ready.
23 MR. QUIRK:
Maybe we could give the GE overview at
()
24 the first meeting, and then if there is a second meeting, then 25 we could get the staff conclusion.
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1 CHAIRMAN MICHELSON:
Well, that's another 2.
possibility.
Let me go back and look at it now that I realize
~
3 I have it, and see-what it looks like, and we will try to. set 4
up'something to, to hit it as soon as convenient for' 1
5 everybody, and,I will ask the PRA Subcommittee to look at it.
6 The fact is I may ask them to write the letter on-7 it.
I don't know It.is kind of a separate subject-in many 8
respects,'and we get so close to the. hardware and so forth 9
that maybe we might, we might lose a little of our perspective 10 on the'PRA.-
A fresh look can sometimes be more helpful.
11 At any rate, we will work out something and try to 12 handle it a little separately in conjunction with the people 13 in our Committee who are much closer to the PRA.
14 MR. QUIRK:
I think Dr. Ward's point is important 15 that the PRA you do have is the internal events PRA.
We have 16' completed our external event PRA, and we will submit it soon.
17 CHAIRMAN MICHELSON:
I am hoping we would not review 18 the external events until the staff has reached a position on 19 external events.
They haven't done it yet so far as I know.
20 Is that' correct?
21 MR. SCALETTI:
We clearly will come to our position 22 on the ABWR external events PRA hopefully sometime this year, 23 put an SER in January of 1990.
.( )
24 CHAIRMAN MICHELSON:
It was my understanding the 25 external events position of the staff would be sometime this HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 fall.
Is that your understanding? ?
{}
2 MR. SCALETTI:
I can't talk to that.
3 CHAIRMAN MICHELSON:
I sure think it is--if we don't l
4 even know what our position is yet, how can we review an 5
external events PRA for any point?
6 MR. WARD:
We can hear what GE has done.
7 CHAIRMAN MICHELSON:
We can hear what they have 8
done.
9 MR. QUIRK:
We are required to provide an rcyrtns1 10 event analysis, and the staff does have guidelines on what 11 that means, and we have scooped up those directions and 12 guidance and have done external PRA, and we want to begin the 13 discussions so, discussion so that the staff position and our 14 review conclude and proceed.
15 CHAIRMAN MICHELSON:
That kind of suggests to me 16 that part at least would be a couple of meetings a few months l
17 apart.
I don't know how, without a position even, I don't f
18 know how we would do it.
19 MR. SCALETTI:
I guess I am not quite sure what you p
l 20 mean by the staff position.
We know the staff position on the 21 ABWR on the external events portion of the PRA.
We have to 22 have that.
l 23 CHAIRMAN MICHELSON:
Is that a published position?
()
24 MR. SCALETTI:
Only until we review it.
25 CHAIRMAN MICHELSON:
I thought you said you had it.
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1 MR. SCALETTI:
We will have one once we do the 2
review.
We are going to have to come up, draw conclusion on 3
the acceptability of the PRA, external events portion as well 4
as internal events, so the staff position with regard to the 5
ABWR will be developed during the course of the review.
6 I feel--I think the intent is somewhat addressed in 7
the Commission paper that was just signed out discussing the s
8 ABWR design enhancements.
IbelkevethatMr.Rubenstein 9
addressed that with the EPRI Subcommittee on the Palo Alto on s
10 a couple, four weeks ago.
That indicates that yes, we are 11 proceeding, we are going forward with the ABWR, and it does 12 discuss to a certain degree the PRA and the intent of the 13 staff, the intent of GE as far as what they have agreed to 14 provide to us, so we will have a position.
15 MR. WYLIE:
I guess what Carl is asking, though, is 16 the staff position on how to handle external events and PRAs 17 that--
18 MR. WARD:
Let Larry show you--and that's--let's 19 see.
Is that related to 1150 or what?
20 CHAIRMAN MICHELSON:
That's related, it is related 21 to the 1150, yes.
It is related basically, though, to the 22 question of how to handle external events, what is the Agency 23 policy on internal events?
It will generate that policy.
().
24 MR. SCALETTI:
The ABWR may help in establishing 25 this policy.
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1 CHAIRMAN MICHELSON:
It might force it.
2 MR. SCALETTI:
So it's--
3 CHAIRMAN HICHELSON:
Hopefully when you are done 4
they are the same.
5 MR. SCALETTI:
Hopefully so; I fully expect them to 6
be.
7 CHAIRMAN MICHELSON:
I would hope so.
Okay.
Why 8
don't you proceed?
9 MR. SAWYER:
Okay.
10 (Slide) 11 MR. SAWYER:
As Joe Quirk indicated, what I--for 12 logical reasons of presentation, I am combining the two topics
()
13 to talk about where we stand on severe accident design 14 features, and then the question that was asked about or what 15 is our position on containment overpressure protection into a 16 single presentation.
Actually, the order will be somewhat 17 reversed because I think it is good to have a perspective of 18 where the plant stands on an overall risk sense in order to 19 have a good discussion on the latter topics.
20 (Slide) l 21 MR. SAWYER:
We submitted our internal events PRA 22 for review at the end of.Tanuary of this year, and I am going l
l 23 to give you the, basically the bottom line numbers for that in
()
24 a moment, but a summary of that is it does show a high degree 25 of protection against postulated severe accidents.
l f
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1 It also indicated to us a few areas where some 2
design enhancements exist which have potential to come up with 3
even better results, give us more severe accident resistance, 4
and the adoption of those features is a subject of an ongoing 5
discussion between us and the staff, and part of the 6
evaluation process to decide mutually whether or not these 7
features do make, do make sense in the overall context of 8
reducing risk.
9 For today, I am just' going to review and summarize 10 the results and describe for you what these possible new 11 features are that we are kicking around between us and the 12 staff.
13 (Slide) 14 MR. WARD:
Let me ask you at this point when you are 15 considering new features, and the desirability of them, 16 what--are you considering the NRC safety goal as part of the 17 context for deciding whether something is desirable or not?
18 MR. SAWYER:
That's a good question.
I think when 19 you see our PRA results, we could afford to, to stand on the 20 pintform that we meet the safety goal as is, and we don't 21 need--really from a cost / benefit point of view in the 22 traditional sense, could make a good case for not, not, not 23 recommending anything additional.
()
24 However, in looking at the big picture, we saw some 25 areas where for minimal cost, we thought that we could make a, i
l HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 a,
what I would say a quantum change, at least in the PRA J
2 sense, in what we calculate the core damage failure or the 3
off-site dose to be, and so taking, taking a broad look at-4 that, we said it makes sense to evaluate these anyway, even 5
though, even though we think that the analyses we provided to 6
date and the anticipated results out of our, out of our 7
internal event analysis we could make a good case for not 8
doing anything.
9 CHAIRMAN MICHELSON:
That's based open your internal 10 events only, is that right?
11 MR. SAWYER:
Of course, in coming up with this, with 12 this set of additional features, even though we haven't 13 published the external events analysis, we know, you know, we 14 are in the process of generating that, and so some, some 15 thinking about what the meaning of those results are going to 16 be has been cranked into, cranked into this thought process, 17 too, particularly which of those features ought to be, you 18 know, ought to have some seismic capability versus which ones 19 don't need to have any, for example.
20 Before getting into what the new features are, let 21 me talk about what we have that has led to the results which 22 are good results that we have already submitted to the staff.
23 You have heard many times in the past from our
()
24 Chapter 4, 5,
6 and 15 presentation what we have in the 25 prevention area.
I'm going to pass over that today and talk HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 about mitigation more than prevention, because I think that's 2
the topic of greatest interest for today's discussion.
3 We have an inert containment which basically deals 4
head on with the hydrogen issues that usually come about when 5
you worry about severe accidents.
6 We have addressed ATWS in terms of reducing its 7
probability of occurrence by adopting the fine motion control 8
rod drives to--it lowers, it removes it from a dominant 9
sequence to a sequence that you need to worry about, but of 10 much less consequence.
We have three full divisions of RHR 11 which provides additional capability for removing heat from 12 the containment as well as, of course, its other functions for
(
13 prevention and normal plant operation.
14 CHAIRMAN MICHEhSON:
Now on this design, refresh my 15 memory.
Does all three divisions have heat exchangers, or two 16 of them?
17 MR. SAWYER:
Three divisions have heat exchangers, 18 and while we are on that topic, I ought to mention that the, 19 the size of the reactor water cleanup system is such that in, 20 if you bypass the regenerative heat exchangers, it is possible l
21 to remove all the decay heat generated by the plant through 22 the reactor water cleanup system at about the four hour mark, 23 so with, of course, that, that's only powered by off-site
()
24 power, but nonetheless, it represents an additional capability 25 that we have in this plant.
l lL b
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1 CHAIRMAN MICHELSON:
You said at the end of four i
2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />?
3 MR. SAWYER:
At about four hours, yes; the reactor 4
water cleanup system itself can handle decay heat.
5 We have a large body of water inside the 6
suppression, inside the containment, the suppression pool, 7
which acts as a filter particularly for iodines and solid-8 fission products, and we have drywell and wetwell spray 9
capability for the containment which provide additional 10 protection against the suppression pool bypass and/or local 11 high temperatures or whatever one worries about when you worry 12 about severe accidents.
()
13 (Slide) 14 MR. SAWYER:
With those features, our internal 15 events PRA in summary gave results that I showed here.
16 I have got basically three columns--what the subject 17 is, what the result is of your analysis, and what the goal is.
18 In core damage, for internal events, we calculate 19 about two times ten to the minus 6 per year.
That's, as of 20 this time, of course, that's internal events only.
The goal 21 is to be less than ten to the minus 5 per year.
That's a 22 commitment we made as part of the EPRI requirements program 23 and also on the licensing review basis document with the
()
24 staff.
That's, of course, for internal plus external, and we 25 think once our external is done, we will show that we meet the HERITAGE REPORTING CORPORATION -- (202)628-4888
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goal.
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i 2
This is a licensing review basis requirement for a
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3 conditional containment failure probability, and our analysis 1
4 shows that the goal is to be less than 10 percent.
Our 5
analysis that we submitted showed 8 percent, so we have met 6
that goal.
7 There is a commitment to show an off-site dose at a 8
half a mile, for events that have greater than ten to the 9
minus 6 probability, to have a dose of less than 25 rem, or 10 said another way, won't exceed 25 rem form any events that cum 11 to ten to the minus 6.
12 CHAIRMAN MICHELSON:
Go ahead.
^
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13 MR. WARD:
Craig, what sort of uncertainty banks do 14 you associate with those probability estimates?
15 MR. SAFYER:
Okay.
Now these analyses that we are 16 talking about here are, are the median calculations.
We have 17 a--
18 MR. WARD:
These are medians rather than means?
19 MR. SAWYER:
Or means really--means.
20 MR. WARD:
They are means, okay.
21 MR. SAWYER:
We have a commitment to look at 22 uncertainties, and we haven't done the uncertainty evaluation 23 yet.
However, it is very difficult to quantify that exactly r'(,)
24 because every time I point out that there is uncertainties in 25 the analysis, I can also point out quite a few areas that are HERITAGE REPORTING CORPORATION -- (202)628-4888
299
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1 important where because of uncertainty, we have taken a i
2 conservative stand as opposed to a mean stand.
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3 In other words, we have tried to analyze the mean 4
where possible, and where it is not clear how to-do it right, 5
we've taken a conservative stand.
So yes, I characterize 6
these numbers mainly as the mean, but uncertainties are the 7
subject of our future analysis, and based on our GESAR 8
experience, I expect the uncertainty bound to be about half an 9
order of raagnitude, something like that, and I don't have any 10 reason to believe that this analysis is enough similar to what 11 we did in GESAR that we shouldn't, we shouldn't expect to see 12 uncertainty banks that are any bigger than that.
13 CHAIRMAN MICHELSON:
Just to be sure I understand 14 your internal analysis, clearly that includes I assume all the 15 events described in Chapter 15?
16 MR. SAWYER:
- Yes, 17 CHAIRMAN MICHELSON:
Now one of the events I believe 18 not described in Chapter 15 is a pipe break outside of primary 19 containment.
Is that correct?
Or are you, or are you now 20 including that as a Chapter 15 event?
21 MR. SAWYER:
Well, we certainly include steam line 22 breaks outside of--
l 23 CHAIRMAN MICHELSON:
I was thinking other than main l
()
24 steam and feedwater.
25 MR. SAWYER:
Other than those?
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1 CHAIRMAN MICHELSON:
Yes.
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2 MR. SAWYER:
In the FRA, we have--if you are worried 3
about things like, I guess what most people call is the V 4
sequence, we have certainly taken that into account in the 5
PRA, even though we have--
6 CHAIRMAN MICHELSON:
Is that a Chapter 15 event?
7 MR. SAWYER:
No, because it requires multiple 8
failures for--
9 CHAIRMAN MICHELSON:
I am trying to find out what 10 the definition of internal event is.
It is more than just 11 Chapter 15.
12 MR. SAWYER:
It is more than just Chapter 15.
In O)
(,
13 other words, we basically go through and build up fault trees 14 and event trees, cascading down to as many failures as it 15 takes to cause core damage.
16 CHAIRMAN MICHELSON:
In the case of the classical 17 event in the reactor water cleanup because I assume here it is 18 still about a 6 inch line that you use?
19 MR. SAWYER:
It is something like that, 6 or 8 inch 20 also.
21 CHAIRMAN MICHELSON:
They vary from 6 to 8 depending 22 on the designer?
23 MR. SAWYER:
Yes.
()
24 CHAIRMAN MICHELSON:
If that is non-qualified, 25 non-safet'1 system, a break in that system has to be isolated HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 by one of two qualified isolation valves, and so that's a 2
scenario which you have done in a PRA I assume.
Finite 3
probability of the break, and I don't know how finite, you l
4 know, what the number would be, but there is a finite 5
probability of break, and it is a finite probability of l
6 failure to close.
7 MR. SAWYER:
Failure to isolate.
8 CHAIRMAN MICHELSON:
Yes, of the valves; now those 9
numbers of, of course, are subject to some conjecture 10 presently, but I assume are using the generic number for 11 valves?
12 MR. SAWYER:
Yes.
13 CHAIRMAN MICHELSON:
Traditionally used in the past,.
14 so that type of event, though, although it is not a Chapter 15 15, isn't part of your internal events analysis?
16 MR. SAWYER:
Yes, sir, it is.
17 CHAIRMAN MICHELSON:
Now what I am trying to find 18 out, when an event becomes external, is a fire internal to the 19 building considered an internal or external event?
20 MR. SAWYER:
Fire analysis that we are doing on the 21 PRA is considered external.
It is external hazard, so it is 22 coming later.
That is correct.
23 CHAIRMAN MICHLLSON:
Now the internal flood from
()
24 the, as a result of the pipe break of the reactor water 25 cleanup, you have got a flood and you have got steam release HERITAGE REPORTING CORPORATION -- (202)628-4888
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}
and so on that goes permeating around to wherever it can go.
1 2
MR. SAWYER:
Internal floods as a consequence of 3
pipe breal are considered in the internal events analysis.
4 CHAIRMAN MICHELSON:
PRA included consequential 5
events of that pipe break where it might permeate to.
6 Can you tell me briefly in the case of reactor water 7
cleanup, which is one of kind of major concern, how you 8
confine that break to certain areas?
9 MR. SAWYER:
Yes.
10 CHAIRMAN MICHELSON:
Are those all in kind of water 11 tight compartments that release to the outside or something?
12 Saw they are in reactor water cleanup specifics?
()
13 MR. SAWYER:
I'm sorry.
I don't have the, the 14 specific answer.
15 CHAIRMAN MICHELSON:
You have considered all that in 16 the process of doing the PRA I hope.
The PRAs sometimes have 17 not been what I would call plant-specific in this regard, but 18 this--
19 MR. SAWYER:
We have taken the specific arrangement 20 and compartmentalization of the, of the plant, into account 21 when worrying about the consequences.
1 22 CHAIRMAN MICHELSON:
Another thing that bothers me 23 about reactor water cleanup, since it is non-safety, the
()
24 ventilation system for it is perhaps non-safety, which means 25 that I might find that the steam that is entering the room HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 will back up through the ventilation ducts and come out.in a lot of places.'n the building whereas the dedicated single 2
t 3
train division, one's ventilation, for instance, as I 4
understood it yesterday, comes in at one place and goes out at 5
one place and never goes anywhere else.
6 MR. SAWYER:
The reactor water cleanup system, of 7
course, is located in the non-safety quadrant of the building.
8 CHAIRMAN MICHELSON:
Its effect can permeate a lot 9
further.potentially because they haven't received the same 10 degree of care as they have been given in the safety system.
11 MR. SAWYER:
The consequences are limited to the 12 non-safety quadrant.
k_)s 13 CHAIRMAN MICHELSON:
But that's a big quadrant of 14 the building.
15 MR. SAWYER:
I understand, but they can't, it can't 16 by itself cross over into the, one of the three divisions.
17 CHAIRMAN MICHELSON:
Hopefully you have done your 18 systems interaction between non-safety and safety correctly 19 and that will be a true statement and we will find out later 20 how you do that analysis.
21 MR. SAWYER:
Yes.
Now by the way, you keep 22 referring to the reactor water cleanup as non-safety, which is 23 correct, but the piping that, the piping classification and
()
24 the isolation classification between high pressure and low 25 pressure is all safety.
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1 CHAIRMAN MICHELSON:
Oh, I hope so.
i 2
MR. SAWYER:
Okay.
1 3
CHAIRMAN MICHELSON:
Yes, but it is operating 4
routinely.
5 This is one case, of all the cases we.have, it is 6
the only case I know of where we routinely circulate reactor 7
water in high pressure, high temperature arrangement without 8
comparable pressure boundary protection that we have wherever 9
else we pipe reactor water.
It is the only place we pipe it 10 routinely into a non qualified system, and it is a large 11 system.
It is not a 1 inch pipe.
It is a, in the 12 neighborhood of a 6 inch pipe, and--much of it is, and it is 13 exotic equipment.
It has got head down heat exchangers and so 14 forth that are just not straight pieces of pipe, and but it is 15 the one case where we, we have seen enough to worry about 16 providing a lot of good pressure boundary around reactor 17 water, and it is contaminated reactor water routinely.
18 MR. SAWYER:
Well, your concern is noted, and I 19 think when we give you, since you have expressed an interest 20 in this area, when we present you our detailed PRA, we will be 21 sure to pick that up as a specific area to make sure that you 22 are satisfied.
23 CHAIRMAN MICHELSON:
Yes.
It is a good area to look
()
24 at simply because it gets involved in the probability of valve 25 closure, which is an important subject for all of your PRA, HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 and it gets involved in the permention of the contamination 2
around the building.
By that I mean water and steam and 3
whatever else and potential effects of those on fire 4
protection systems, and whatever else.
It gets the whole ball 5
of wax from a break.
That's--I am also interested in your 6
probability numbers.
7 Does a non-seismically qualified system have the 8
same probability of random failure as a seismically qualified?
9 Well, it doesn't have the same QA or controls.
It doesn't 10 have the same material controls.
A whole lot of things are 11 not the same, and yet they are perhaps reducing the same 12 probability of failure, which doesn't seem to be quite
(
13 rational, but maybe you have correction for that.
14 MR. SAWYER:
I don't think we are using the same 15 probability of failure particularly.
16 CHAIRMAN MICHELSON:
I would think it is somewhat 17 higher.
18 MR. SAWYER:
And of course when, for seismic, that 19 gets into the seismic PRA.
Of course, in there what we do is 20 we generate fragility curves, and equipment that has been 21 specifically designed to meet SSE type requirements is going 22 to have basically more capability for larger earthquakes than 23 equipment which does not, and that will be accounted for in
()
24 the seismic PRA.
25 CHAIRMAN MICHELSON:
That's the sort of HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 thing--that's why reactor water cleanup is a good one to look 2
at to kind of get your general approach to this interface 3
question, and I think if we look at our reactor water 4
carefully, we can see what you are doing.
5 MR. QUIRK:
Mr. Michelson, may I just make a 6
statement with regard to your inference that the pressure 7
boundary standards for the reactor water cleanup seem to be 8
slight?
That's the impression I am getting.
9 I just want to remind you that the portion of the 10 reactor water cleanup system that is reactor pressure boundary 11 is designed to quality group A standards through isolation 12 valves.
13 CHAIRMAN MICHELSON:
Let me remind you that, that we 14 have a great deal of the reactor water in, in piping which is 15 not pressure boundary qualified.
16 MR. QUIRK:
I was going to get to that.
I wanted to 17 point out there is a portion of the reactor water cleanup 18 system that is quality group A, the highest standards of 19 pressure integrity, and it is at, through the isolation 20 valves.
21 Now there ie then the reminder of the system that is 22 not quality group A and is not safety-related.
23 CHAIRMAN MICHELSON:
Is routinely open.
()
24 MR.,
QUIRK:
Is functioning during operation, subject 25 to reactor pressure.
For the bulk of that system, we have HERITAGE REPORTING CORPORATION -- (202)628-4888
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opted to exceed minimum requirements and designed it to
)
()
2 quality group C, which is ASME and are high quality we 1
l 3
believe, so I just want to point that out.
I 4
CHAIRMAN MICHELSON:
I recall, though, that only a 5
small portion of it was quality group C.
We got into this 6
when we talked about that big low table at our first meeting 7
or second meeting remember, and I think there was a lot of 8
question about what was, how far did this go, and we can get 9
that cleared up at the appropriate time.
10 MR. SAWYER:
Okay.
I think your comments are well 11 noted, and we will be prepared in our future PRA discussion to 12 discuss it.
()
13 MR. WARD:
I want to ask you kind of a more general 14 question about the probability estimates again.
15 You gave a, an estimate of the uncertainty bank as 16 perhaps half an order of magnitude, which is rather I think 17 more optimistic than a lot of estimates one hears from PRAs, 18 and I realize that may be a matter of definition of the bounds 19 or it may be that it is very difficult to describe those 20 bounds.
With the state of the art maybe it is really 21 impossible, but you know, with regard to the safety goal, and 22 the fact that these numbers and numbers for other plants are l
l 23 coming out looking rather comfortable compared with the safety
({)
24 goals, I mean the soft area and the whole thing is the matter 25 of uncertainty and there is a commitment and the agreement BERITAGE REPORTING CORPORATION -- (202)628-4888
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that safety goals are expressed as probability numbers, are i
2 expressed as mean values, and PRAs are directed toward that.
3 I think that's fine, but yet the softness in the whole thing 4
is in the uncertainty.
5 Now have you done anything--in fact there could be 6
some argument made that the, we are in good shape on the mean 7
values, but what we need to do is to develop methods of 8
analysis or to design plants or to operate plants in a way 9
that these sorts of uncertainties are reduced, and that would 10 he directing the design toward reducing uncertainty rather 11 than reducing mean values of these risk, risk parameters.
12 I don't know whether that's possible or not.
It is (3
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13 something that has been discussed, but have you, have you
.14 thought about that sort of thing?
I mean in bringing to bear 15 PRA as a tool on the designer, to feed back the designer, have 16 you considered only the mean values, or do you consider what 17 the PRA is telling you about uncertainty?
18 MR. SAWYER:
I'm glad you asked that question 19 because one of the reasons why we are presenting an 20 opportunity for further enhancements is that we weren't, j
21 because of considerations such as uncertainty that you 22 mentioned, we weren't entirely comfortable at saying that, at i
23 claiming victory because we were just less than this, than the
()
24 goal.
25 One way in which you can handle uncertainties is to HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 beat the goal by a comfortable margin.
Okay.
That's one way 2
of handling uncertainties.
3 With regard to--that's probably the feedback that 4
you would see in the plant hardware.
Other than that, I don't 5
see how uncertainty analysis per se can tell you more about 6
the vulnerabilities, more about the vulnerabilities of the 7
plant.
8 You are getting more into the technology of how you, 9
how you estimate these things in PRA in the first place, and I 10 think our position is where we, where we see a chance to meet 11 the goal comfortably, in other words, where you look at the 12 areas and see the greatest sensitivity if you will to, to what fx
(_)
13 your assumptions have been, then that's why we have said well, 14 let's see what we can do to beef up that area, but that's l
15 really the only way in which we are addressing the uncertainty 16 analysis so far.
17 MR. WARD:
Okay.
Thank you.
18 MR. SAWYER:
In addition to the other two mentioned 19 goals, there is another way of looking at what the risk is 20 which has to do with off-site dose at a half a mile at ten to j
i 21 the minus 6 probability, and I mentioned that our goal is to 22 be less than 25 rem at that probability, and the analysis 23 which we have submitted shows that the cum at that ten to the
()
24 minus 6 probability came to about 15 rem.
25 One other factor in taking a look at, at their 1
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1 mitigation capability is how long does it take for the 2
containment to reach its failure pressure?
And of course, 3
this, this is saquence dependent, and you-come up with--there 4
is all kinds of ways of looking at it, but you can come up 5
with a kind of weighted number that depends, is weighted over 6
your dominant sequence, and typically our analysis has shown 7
for the ABWR containment that it takes, it takes well over a 8
day, approaching two dcys before you are talking about 9
containment pressures reaching failure pressures, so there is, 10 there is a comfortable amount of time that independent of PRA 11 considerations, give you shall I say a good feeling about the 12 resilience of the design.
13 As you know, once you begin to get out, once you try 14 to execute PRA type methodology, and you look at, at recovery 15 sequences, beyond a certain point, it is almost impossible to 16 quantify because your choices are too numerous, and so about 17 the only thing you can, you can do at that point is take a 18 look at whether or not there is enough time out there and make 19 a judgment that that's, that's a good result in terms of 20 giving the plant staff a lot of flexibility to deal with the 21 situation beyond what you can quantify in a PRA.
22 I said at the beginning, let me say again, these 23 results do not include the effects of external events.
We are
()
24 in the final throws of getting that written up and submitted 25 to the staff, and based on where we stand, we think we will HERITAGE REPORTING CORPORATION -- (202)628-4888
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{}.
'l meet the goals even with, even with external events accounted 2
for, although course, we will be closer.
3-MR. WARD:
When you say that the, for dominant, the 4
time to exceed containment pressure for dominant sequences, 5
are those dominent from the standpoint of core melt risk, 6
contribution to core melt risk, or off-site dose?
7 MR. SAWYER:
Both, okay, but the, it turns out that 8
if you look at the difference in off-site dose or an event 9
which fails containment in let's say five hours versus 10 condition in 40' hours, you are talking about a factor of 11 three, something like that.
It is not orders of magnitude 12 more dose delivered as a result of early failure, but, but the
()
13 number I am characterizing here is for dominant sequences 14 which are typically transients with no, with no makeup either 15 because I had a Station Blackout or because all my, one way or 16 another, all my, all my equipment which is in the plant to 17 deal with the situation wasn't available for a long time.
18 Those are really the dominant, that's really the dominant 19 sequence that we have identified for the plant.
20 (Slide) 21 MR. SAWYER:
Well, for all the reasons we have been 22 kicking around here, we decided to take a look at what some 23 additional features could do to further strengthen the design
()
24 from a severe accident standpoint, and there is a large number 25 of choices that can be made in principle, but the practical HERITAGE REPORTING CORPORATION -- (2021628-4888
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ones that we have chosen to zero in on for further evaluation 2
are these--the use of gas turbine to back up the diesels, the 3
use of an AC independent water addition system, a lower 4
drywell flooder, and containment overpressure protection, so 5
those are the four topics I'm going to talk about basically 6
for the remainder of this discussion.
7 (Slide) 8 MR. SAWYER:
In each of the systems, I am going to 9
give you a brief overview of what the thing looks like, why we 10 are doing it, how it works, and what we think the benefits 11 are, and then in our ongoing discussions with the staff, and 12 then eventually with you, we will quantify what, what we
()
13 perceive the risk / benefits in either core damage or in 14 off-site releases are as a result of adopting these features.
15 First, the gas turbine--it is basically an alternate 16 AC power source in the AAC definition as provided in the 17 Station Blackout role.
It is required by the EPRI ALWR 18 requirements program.
It is not seismically qualified.
19 Therefore, it doesn't give you much benefit in external events 20 analysis, but from a common mode failure potential point of 21 view for internal events analysis, it has great benefit, and o
L l
22 it just shows, this one-line sketch here shows basically how 23 we plan to plug a gas turbine unit into the plant with 24 capsbility to back up both the, two of the four operational
()
l 25 buses that have systems we would like to see keep running in HERITAGE REPORTING CORPORATION -- (202)628-4888
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I the event of a plant emergency, and as well as any of the, of 2
the emergency divisions in the plant.
3 Its operation is reasonably simple.
Our 4
expectations are we can get, get a gas turbine up and running l-l 5
in five minutes or so.
It is not intended that the use of 6
such a system would be to respond to DBAs in the traditional
- 7 DBA sense, but that it be basically used as a backup, and that 8
backs up basically our judgment based on our PRA that the 9
major threat isn't one of LOCA followed by all diesels failing 10 to operate, but it is really a transient'such as loss of 11 off-site power, which is dominating the risk in this area, so 12 its benefit is clear.
It reduces the frequency of Station O
\\/
13 Blackout for internal events analysis.
14 CHAIRMAN MICHELSON:
Roughly what would be the size 15 relative to the need of the three divisions?
16 MR. SAWYER:
Well, we wouldn't plan to size it to 17 back up all three divisions, but one of the three.
18 CHAIRMAN MICHELSON:
Just one of three?
19 MR. SAWYER:
Yes.
No particular reason to size it 20 to back, to back up all three, but because of the breakering 21 system, the operator can choose which one of the three is, is 22 it--is his choice which one to plug it into, but typically a, 23 each division typically takes between four and five megawatts
()
24 to run, and so we haven't chosen the final size of this 25 alternate AC system, but it would certainly overall be in the HERITAGE REPORTING CORPORATION -- (202)628-4888
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314 j) 1 range of,-I don't know, 6 or 7 megawatts.
2 CHAIRMAN MICHELSON:
Is your shutdown cooling i
3 non-LOCA case adequately handled by one division?
l 4
MR. SAWYER:
Yes.
5 CHAIRMAN MICHELSON:
If that's the case, you are 6
putting this in for no LOCA, no accident really?
Just loss of 7
off-site power.
8 MR. SAWYER:
That is correct.
9 CHAIRMAN MICHELSON:
One division will do that?
10 MR. SAWYER:
One division will do that, that's 11 right.
12 CHAIRMAN MICHELSON:
Now the gas turbine requires 13 certain auxiliary and fuel sources and so forth.
14 Are they going to be completely independent of any 15 one of the diesels?
16 MR. SAWYER:
Yes.
17 CHAIRMAN MICHELSON:
There will be no common fuel 18 supply other than the same truck?
It is the same fuel I 19 thi nk.,
20 MR. SAWYER:
I don't even think it is the same fuel.
1 21 I think--I could be corrected, but I think that the fuel used 22 for gas turbines is more like kerosene as opposed to diesel.
23 CHAIRMAN MICHELSON:
It may be.
I'm not that
()
24 familiar with the gas turbine.
If it isn't the same fuel, 25 there is also the common mode failure of bringing the gas l
l HERITAGE REPORTING CORPORATION -- (202)628-4888
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turbine fuel in and sticking it in the diesel tanks and vice O
2 versa.
3-MR. SAWYER:
You would find that out on your monthly
)
4 surveillance. pretty fast.
5 CHAIRMAN MICHELSON:
You would find it out in a 6
hurry, that's right.
7 MR. WARD:
Since--excuse me.
With the five-minute 8
start time requirement, is that an off-the-shelf gas turbine, 9
or is that enhanced in some way?
10 MR, SAWYER:
Our understanding, EPRI is really 11 taking'the lead in defining what the specific requirements are 12 for, for these gas turbines, but the kind of gas turbines that
()
13 General Electric, for example, supplies have start times at 14 the, that are of that order, without requiring any enhancement 15 in the technology.
16 MR. QUIRK:
Off-the-shelf.
17 MR. WARD:
Is the reason for specifying a gas 18 turbine there just to have something that is diverse from the 19 diesels where you don't worry about as much about common--
20 MR. SAWYER:
That is correct.
Are you saying that 21 why take a gas turbine.as opposed to a fourth diesel?
That is 22 absolutely correct.
23 MR. WARD:
Yes, fourth diesel, or if you are at the
()
24 site where you had a dam, you could have a, a--
25 MR. SAWYER:
I have--
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MR. WARD:
Water turbine perhaps.
2 MR.' SAWYER:: We have specified this.
I think our I
3
-intent would be that if a specific utility requested an 4
exemption on the grounds that he had, he can meet the AAC l
5 requirement with something else such as a. nearby dam, that 6
would be acceptable.
The intent basically is the power supply 7-is diverse from the diesels.
8 CHAIRMAN MICHELSON:
Was-this intended to be tornado 9
protected?
10 MR. SAWYER:
Excuse me?
11 CHAIRMAN MICHELSON:
Was it tornado protected?
.12 MR. SAWYER:
No, no external event.
The
()
13
. considerations that were put on the table between EPRI and the' 14 utilities that expressed interest in having this capability
.15 were that they didn't see the risk of external events being 16 the risk that they were worried about, and'so they made it 17
'very clear in their directives to the industry that they 1
18 wanted diversity from the diesels, but that they also didn't, 19 they weren't really worried about external events.
They were 20 really worried about common mode failures of the diesels just 21 due to normal operation.
That was their primary concern.
22 MR. WARD:
And the numbers come out that way even 23 though external events are surely a cause of loss of off-site
()
24 power in the first I, lace?
25 MR. SAWYER:
That is correct.
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1 MR. WARD:
It isn't real obvious out of hand.
It 2
must:be that the probability--
l 3
MR. SAWYER:
First of all, we are coming from a 4
position that says we believe that we are already adequate 5
enough in thia area as far as meeting the safety goal is 6
concerned.
7 The question is when do you stop spending money?
I 8
mean if you, if you come to a determination that seismic 9
events are the dominant risk, the natural question is let's go 10 in with the super-seismic gas turbine, but that that would 11 make it, I think it would make the costs of that, such a 12 system, prohibitive I don't think, I don't think the I
13 industry would be interested in a system on that basis.
14 MR. WARD:
So loss of off-site power from other 15 causes is of a much higher probability than loss of off-site 16 power--
l 17 MR. SAWYER:
In a seismic event, sure; sure.
18 MR. WYLIE:
I suspect EPRI picked the gas turbine 19 because of the cost, lower cost.
I mean you could buy a 20 bigger diesel, different manufacturer.
I'm sorry, but I didn't understand the first part of that question.
22 l
l 23 MR. WYLIE:
I said the EPRI picked the gas turbine l
()
24 since they are lower cost than the diesel.
1 25 MR. SAWYER:
Yes, they did.
By placing what I call, L
HERITAGE REPORTING CORPORATION -- (202)628-4888 l
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-(~)-
1 what I would call gentle requirements on the gns turbine, it v
2 is affordable.
3 MR. QUIRK:
I don't think that was the deciding 4
factor from EPRI.
I think they were looking for diversity 5
here.
6 MR. WYLIE:
You can get diversity with a different 7
type of diesel, That's something you could argue back and 8
forth.
9 MR. QUIRK:
To some extent you can.
They 10 chose--this would be a much cheaper,, diverse way.
11 Craig, I would like to put in perspective the fact 12 that the ABWR design with the three divisions has basically N 13 minus 2 capability when assessed against realistic 14 requirements, and that one could argue that three divisions is 15 adequate, and as such, no further backup needs to be made.
16 However, to, to be complimentary with the EPRI 17 program and provide the robust forgivable design that they are 18 looking for, we have, as Craig has shown here, augmented our 19 design with it, and we think it really is something that 20 provides a lot of capability and a lot of--and I just want to 21 point that out.
l 22 MR. SAWYER:
The second feature that I am going to l
23 discuss is the, what we call an AC independent water addition f-s fj 24 system.
25 There is an EPRI requirement where they want to have I
l l
1 I
i HERITAGE REPORTING CORPORATION -- (202)628-4888 J
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connection to decay heat removal lines for introduction of 2
water to the drywell directly independent of normal, 3
independent of normal systems, normal being defined as 4
basically the AC power, ECCS complement.
This is a Chapter 5 5
requirement in the'EPRI requirements program.
6 The way in which we are talking about implementing 7
this is basically to use the existing fire water system in the 8
ABWR., which among other things, has a diesel, direct drive 9
diesel pump, doesn't require AC power.
10 And the salient features of this system are there is 11 a dedicated tank which I haven't shown, a fire, for fire 12 water, and here is the fire pump, fire water standpipe,
()
13 capability for an external connection for a fire truck, which 14 that's new.
The capability to cross-tie it into one of the 15 three low pressure ECCS systems, this shows low pressure pump 16 either into injection mode, into the vessel, or into spray, 17 into the spray header to spray into the drywell.
~
18 The way it works is there is no high pressure core l
19 cooling available and no low pressure injection pumps 20 available, manually depressurize the reactor vessel, close one l
1 21 valve, which is this valve, open three valves, and you get
{
22 backup injection to the vessel.
l 23 CHAIRMAN MICHELSON:
How low pressure do you think
()
24 you have in tha vessel?
25 MR, SAWYER:
Well, if you depressurize the reactor, HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 depending on what time you are talking about, you can get the 2
reactor all the way down to ambient.
l l
3 CHAIRMAN MICHELSON:
The safety valve you are going 4
to lose will take you down to--
1 5
MR. SAWYER:
These kind of valves will stay open to 6
reactor pressures down below 50 psi.
7 CHAIRMAN MICHELSON:
Will stay open forever I think; 8
manual arms, as'I recall, which you suggested it was a manual, 9
it was a remotely operated manual arm, and the safety--
10 MR. SAWYER:
Yes.
These valves aren't pilot 11 operated.
They are power operated, and they will stay open.
12 CHAIRMAN MICHELSON:
Just pull the hand crank or 13 hand lever on them.
14 MR. SAWYER:
So from a severe accident viewpoint, we 15 have son:e options.
By introducing it directly to the vessel, 16 that's the, there is a prevention capability.
17 If, unfortunately, things have gone awry, and there 18 is a rupture, that water will end up in the lower drywell in 19 any case by this addition to the drywell.
20 Furthermore, as you may remember from the 21 arrangement drawings, the drywell is split into what we call l
22 upper drywell and lower drywell.
This pathway would address 1
23 water addition to the lower drywell.
This pathway would
()
24 address water addition to the upper drywell.
For primary 25 purposes, that would be, basically a washout of fission HERITAGE REPORTING CORPORATION -- (202)628-4888
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321 i
ry 3
products or reduction of local high temperatures,_ depending on U
2 what your concern would be.
3 CHAIRMAN MICHELSON:
You are suggesting this only 4
for one of the RHR loops?
5 i!R. SAWYER:
Correct.
6 CHAIPMAN MICHELSON:
And it still--then this is a 7
finite probability of opening the valve when you need to open 0
it and so forth?
9 MR. SAWYER:
The considerations that we have given 10 to that--now you are getting into the next level of design 11 detail.
The considerations we are giving to that is to makes 12 this valve capable of manual, manual operation by sending the
()
13 operator out there to open it.
14 CHAIRMAN MICHELSON:
Under there, the postulated 15 circumstances that we are talking about, do you think you will 16 get a volunteer to go that close to the reactor?
17 MR. SAWYER:
We would presume it would call for the 18 system well in advance of having lots of fission products 19 around.
20 In other words, I think the control, I think 21 the--this is not intended as a last ditch.
22 CHAIRMAN MICHELSON:
You don't mind putting the fire 23 water in earlier?
l 24 MR. SAWYER:
Put it in as soon as, I think our
[}
25 considerations are as soon as the operations crew deternine
~~
322
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1 that they have lost their traditional makeup capability 2
through their, through the other systems, they are going to 3
dispatch somebody to get this, this system on the line as soon 4
as they can.
5 CHAIRMAN MICHELSON:
It is a, you know,'it is a very 6
degraded circumstance already when none of the RHR will work.
7 I mean you probably have lost power to everything.
It is not, 8
it is the same situation as going down there today and doing 9
it.
10 MR. SAiTYER:
Yes.
11 CHAIRMAN MICHELSON:
It is a, it is very degraded 12 before you even start to worry about bringing fire water in, r's
(-)
13 Might not get a volunteer.
14 MR.-QUIRK:
Well, for that case, you still have the 15 RCIC available to provide makeup.
But I would, I would--
16 CHAIRMAN MICHELSON:
I would assume you don't use 17 RCIC.
You don't use this until RCIC is--
18 MR. SAWYER:
This is the--
19 MR. QUIRK:
Last ditch prevention system.
20 MR. SAWYER:
This is the last thing you try after 21 you determine the other ones don't work.
22 CHAIRMAN MICHELSON:
In the vicinity of the valve, 23 you are going to try to manually operate--how long do you n-( )
24 think it will take to open that valve manually?
25 MR. SAWYER:
Let me back up.
I think a better HERITAGE REPORTING CORPORATION -- (202)628-4888
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question is how long do you think it takes to get such a V
2 system working starting from scratch after you made the 3
determination our--I guess that is, that it is the order of 4
half an hour to an hour to get this system going.
It is not 5
intended as a, as an automated ECCS type backup system.
6 CHAIRMAN MICHELSON:
That manual crank on the valve 7
will probably take you 20 minutes alone after you get-to the 8
valve.
9 MR. SAWYER:
I understand that, okay.
And it 10 also--that's right.
11 CHAIRMAN MICHELSON:
That's a long time to reside in
.12 the degraded environment.
That's fine.
It is last ditch.
13 Hopefully you have got a brave volunteer; heroic action.
14 MR. SAWYER:
I wouldn't characterize it quite as 15 heroic yet.
Where that valve is operated, it woul6 take a 16 considerable period of time that I would guesstimate to be 17 several hours, that at least before, before you have what I 18 would call heroic actions required because of local 19 temperatures or whatever.
20 CHAIRMAN MICHELSON:
You don't know what the 21 situation was that finally led to the loss of all ECCS.
That 22 could have been already in a degraded core condition.
23 Everything was working fine, and then it, then the environment
()
24 of the building changed and the power crapped out.
Up to that 25 point, you were circulating whatever the crappy water from the I
{
HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 drywell or wetwell is right around through our RHR perhaps 2
trying to cool the drywell, I mean the wetwell area, and in 3
that case, man, it's hot as a firecracker on that valve.
4 MR. SAWYSR:
If that's the scenario then, and it 5
also turns out that that valve is not capable of remote manual 6
operation, then we wouldn't send a guy out, and it was a bad 7
day and we just lost the plant.
At some point you have got to 8
say, at some point you have to give up and say I cen't deal 9
with the situation anymore.
10 What we are proposing I think is sort of a 11 practical, a practical way of enhancing the capability without 12 trying to make it totally bunkered O
(_/
13 MR. QUIRK:
The capability of the plant to ride 14 through a blackout is like eight to ten hours?
Is that 15 correct?
16 MR. SAWYER:
The capability of the plant to ride 17 through the, through a blackout, we have promised a minimum of 18 eight to ten hours.
If you, if--this is jumping ahead to our l
l 19 next, one of our next discussions, but if you open, if you l
l 20 open the containment, you have essentially many day l
21 capability.
22 MR. QUIRK:
I was just trying to establish that for l.
23 the case where you have lost all your three divisions, with 3
1
()
24 the RCIC and DC batteries you do have the capability to ten 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> to keep things well in control.
HERITAGE REPORTING CORPORATION -- (202)628-4888 i
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l' MR. SAWYER:
That is clearly not available, either, 2
although I wouldn't even be talking about the system, Yes.
3 For drywell spray usage, the situation is pretty 4
much the same except it takes one more valve to access the 5
drywell spray to get the system running.
6 The benefits of it are it doesn't depend on AC 7
power, so it basically acts as additional backup to the low 8
pressure injection function, just like the RCIC acts as an AC 9
independent high pressure injection system, and also a backup 10 for the drywell spray function.
11 CHAIRMAN MICHELSON:
Did you really mean two valves 12 on that spray line, or one?
You showed two.
13 MR. SAWYER:
There are two.
14 CHAIRMAN MICHELSON:
You have to open them both, the 15 two valves?
16 MR. SAWYER:
That's right.
In this case, if you 17 look at the lineup that we have shown here, it takes a total 18 of four valves to get it going.
)
19 The entire system is--
20 CHAIRMAN MICHELSON:
The spray valves, how 21 accessible are they?
Are they such that you can get direct 22 access to the operator?
23 MR. SAWYER:
One of the GE guys may know.
Gail, do
()
24 you know?
25 MR. MILLER:
All of those valves are within six or HERITAGE REPORTING CORPORATION -- (202)628-4888
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eight feet.
-{}
2 CHAIRMAN MICHELSON:
You mean you put the spray' 3
valves on the RHR_ injection?
In the same room; they used to 4
be.way up.
RHR was one area and the others were 30' feet up in 5
'the air from'that because.they went up high.
6
'(Slide) 7 MR. SAWYER:
The last point I want to make on.here 8
is all the components of this system, since we are using the.
9 fire, basically the fire system as part of this protection, is 10 already seismically qualified, so this particular system as 11 opposed to the gas turbine has considerable capability, even 12 in terms of external events.
)
13 CHAIRMAN MICHELSON:
Wait a minute.
Are you saying 14 now that the fire protection piping would be seismically 15 qualified?
16 MR. SAWYER:
It is already.
17 CHAIRMAN MICHELSON:
Oh, you are going to use 18 seismically--
19 MR. SAWYER:
Yes.
20' CHAIRMAN MICHELSON:
I didn't realize it was a 21 seismic design fire protection.
22 MR. SAWYER:
Yes.
The fire protection system is 23 seismically designed.
()
24 CHAIRMAN MICHELSON:
Okay.
i j.
25 MR. SAWYER:
That's one of the reasons why we chose l
HERITAGE REPORTING CORPORATION -- (202)628-4888
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I this particular network as opposed to some other choices.
2 CHAIRMAN MICHELSON:
Okay.
The fire engine that's 3
required to accomplish this flow, how will that be treated?
4 Just as available locally?
The Fire Department or something?
5 MR. SAWYER:
Yes.
What we are doing is providing 6
the capability, the external boundary at plant for hookup.
7 CHAIRMAN MICHELSON:
That will put certain interface 8
on that fire pump that is in that, on the--
9 MR. SAWYER:
Yes, but our sutveys have shown that 10 the head capability of pumps--I didn't mention the head.
The 11 delivery head is somewhere between a hundred, 200 psi, okay, 12 and that's typical of the head you are going to have on fire 3e W
13 truck fire pumps also.
14 CHAIRMAN MICHELSON:
There will be a defined 15 interface requirement?
i 16 MR. SAWYER:
Yes.
17 CHAIRMAN MICHELSON:
Okay.
18 (Slide) 19 MR. SAWYER:
The third feature that we are 20 considering is the what we call lower drywell flooder.
This 21 is also required by the EPRI ALWR requirements program, and 22 what we, what we have been led to consider is a passive means 23 of accomplishing this by basically providing a number of
()
24 ennections between the suppression pool and the lower drywell 25 piping basically what we call fusable link valves, which means I
l HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 that the valves are actuated strictly by means of local high 2
temperature.
3 By local high temperature, we mean temperatures in 4
the order of six or seven hundred degrees'Farenheit, 5
temperatures in excess of what you.would expect to find unless
'6 you have a core on the floor situation in a lower drywell.
7.
Its operation is pretty simple.
High temperature, 8
high lower drywell temperatures after vessel failure will melt 9
the plug.
Pressure suppression pool water will come to 10 equilibrium between the suppression pool and the lower 11 drywell.
'12 CHAIRMAN MICHELSON:
Now how--to get 700 degrees j
13 Farenheit, you have got to have what, 4,000. pound steam?
14-MR. SAWYER:
No.
To get to 700 degrees Farenheit, 15 you have to have, if you have, if you have steam, then your 16 core on the floor is under control.
It's when you don't have 17 steam that you are worried about it, and that's the reason for l
18 this backup system is to, is to provide that capability for l
19 those scenarios in which all the water is gone.
6 f.
20 CHAIRMAN MICHELSON:
Yes.
If there is any steam 21 around the fusable link, it will not melt.
1 22 MR. SAWYER:
That is correct.
In fact, the design 23 of the system has to worry about that specifically to isolate
()
24 the fusable link from the water in the pipe for the same l
25 reasons.
l l
l HERITAGE REPORTING CORPORATION -- (302)628-4888
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CHAIRMAN MICHELSON:.How far up from the floor is
'2 that link going to be?-
3 MR. SAWYER:
What is it, Gail?
About a meter, half-4
- a. meter, something like that, right?
5 MR. MILLER:
One to 2 meters.
6 MR. SAWYER:
Okay.
We have worried about locating 7
it from that perspective whether or not--by the way, I just, 8
as a glance ahead to our, to our internal events PRA, I ehould' 9
also mention that this, this function will occur anyway in 10
.about ten hours.
11 CHAIRMAN MICHELSON:
It will go through the wall.
12 MR. SAWYER:
Yes, because as you know, we have v
13 vertical vent pipes at various locations in this separation 14 wall, and at those locations, the concrete thickness is a lot,
'15 lot less than it is for most of the pedestal, so our analyses 16-have said that in about eight to ten hours, you are going to 17 get this effect anyway.
The reason for putting this in is to
(
18 cut it off much earlier than that, and it'is relatively easy 19
'to do.
20 CHAIRMAN MICHELSON:
How many of these fusable link 21 valves do you think you will have?
22 MR. SAWYER:
Do you remember, Gail?
Is it four or u
23 six?
().
24 MR. MILLER:
We are talking the order of five to 25.
ten.
1
~
HERITAGE REPORTING CORPORATION -- (202)628-4888
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. CHAIRMAN MICHELSON:
How-large?
'2' MR. MILLER:
.Oh, 4 inches.
3-MR. SAWYER:' Four inch. lines I think we are looking 4
at.
5 To put these ideas in perspective a little bit,.let 6
me explain that we haven't completed the system engineering on 7
.these.
They basically were, if I recall,' composite level 8
engineering ideas that came out of the PRA,-and we have 9
described the functional requirements for them, and we are
.10 just in.the process right now of trying to get into the next 11 level of engineering detail, you know, what would the line 12 sizes be exactly, what do the valves look like, et cetera, et
- (
13.
cetera, so what'I am.trying to present to you today is more-14 the philosophy of-why we are doing it as opposed to the 15 detailed system design.
16 Benefits--it is clearly very reliable.
It is 17 passive, has high seismic capabilities.
Its function is
[
11 8 basically to quench corium as soon as possible, stop that I-19 core / concrete reaction and reduce the drywell temperatures and 20 therefore leak potential that can happen from the drywell 21 directly to the outside world that can occur because of 22 piping.
23 (Slide)
({}
24 MR. SAWYER:
Okay.
Now let's go to the fourth one, L
25 which I think is the most controversial.
This is a HERITAGE REPORTING CORPORATION -- (202)628-4888
331
~
1 many-faceted discussion.
2 Containment overpressure protection--I think we 3
already reviewed with you what our goals have been in terms of 4
core damage, dose, and the need to meet additiona1' containment 5
failure probability that you find in our licensing review 6
bases document.
7 One point of the, subject of discussion that led to 8
consideration of this feature was basically how do you define 9
containment failure?
And that is a subject of an ongoing 10 dialogue between us and the NRC, and I don't think we have 11 reached a final, final agreement on that yet, but I should 12 point out for, for the ACRS that our, that the current PRA
()
13 which we have submitted basically defined failure as orc..Ler 14 than 25 rem at a half a mile, our definition of failure.
It 15 is consistent with the goals that were laid down, 16 It was our thinking that that.was the intent of the 17 goal, that the containment failure is basically based on 18 functional considerations of the containment function as 19 opposed to considerations of the containment as a, as a 20 pressure vessel.
21 However, the staff in their review of our, of our l
22 submit, has come back and said please give us an evaluation of 23 what it means to consider a pressure boundary definition of
(}
24 containment failure, and it is this consideration that has 25 basically put on the table what do we do if that, what do we E --""" P^"" """ = "" ? "" " " " -- <2023e28-4888
l 332
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1 do in this area if that becomes the basis for, for the 2
definition of containment failure?
3 And if it does, an additional feature may be 4
required, and it depends, I think whether or not we actually 5
put in this feature will basically depend on the outcome of 6
those discussions, and we are not prepared today to, to tell 7
you the results of those, and I think that will be the subject 8
of our meeting with you the next time when we talk in more 9
detail about PRA.
10 But let me just, just to make things a little more 11 concrete in terms of understanding what it is we are talking 12 about here, if we need to put in some kind of overpressure 13 protection function, the rationale for it is as follows--we 14 would install a, a line between the wetwell air space and the 15 stack, rupture discs, and normally open valves.
16 The intent is to make this, when you get down to 17 where your only two choices are to stand back and watch the 18 containment fail wherever it wants to fail, or to have some 19 feature that causes a benign failure, and this is the system 20 that would accomplish that, and the intent is that the l
l 21 operator doesn't have to do anything.
We are not asking the l
l 22 operator to make a vent decision.
This decision happens due i
l 23 to design.
()
24 The operator's decision is to close it.
When the 1
25 containment, containment situation is under control in a l
HERITAGE REPORTING CORPORATION -- (202)628-4888 1
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1 l'
l 333
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1 recovery scenario, we want to make it passive.
It is our 2
intent that it,.it really, in real terms, quantifiable terms,-
l 3
is never used.
We want to design it so'it can't be misused.
4 There is other, I know there are other designs that 5
have been kicked around to address this area which involve the 6
operator directly in the, in this mitigation feature and 7
therefore lead to considerations of what if he had, panics and 8
inadvertently opens things too early when he could have waited 9
and something else could, in the plant would have happened and 10 he wouldn't have had to open it at all?
So it addresses that 11 issue.
12 It assures benign failure because we take advantage f^\\.)/
13 of the scrubbing of the suppression pool, elevated release, 14 and this would virtually eliminate doses in excess of 25 rem 15 from any scenario.
16 By failing in this manner, the, the considerations 17 of loss of core cooling water because of potential failures, 18 pressure boundary failures of valve load which could drain the 19 suppression pool are removed.
It has high seismic capability, 20 and because of its passive nature, low failure probability.
21 So that's the, that's what we would come up with to 22 meet, to meet a pressure boundary definition of, of 23 containment.
()
24 MR. WARD:
Are you saying you have designed 25 something that will do these things, or these are the HEnITAGE REPORTING CORPORATION -- (202)628-4888
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requirements for something you are going to try to design?
2 MR. SAWYER:
What we are saying is that the staff i
3 has asked us to evaluate other definitions of containment 4
failures than those that we have, that we went in with in our 5
PRA, and in the process of that, what we have done is, from a 6
hardware standpoint, come up with a design that looks in 7
principle something like this, which meets those requirements.
8 The rupture, the failure pressure of the rupture 9
disc would be set above design pressure and as close to 10 rupture, as close to the ultimate failure as we can from our 11 point of view and the staff from their point of view agree on.
12 The point is that to minimize the potential for the
()
13 concern of if I had only waited a little bit longer, something 14 else good might have happened, okay?
And so we are trying 15 to--basically this is, this is what I call the last of the 16 last ditch things that you put in the plant after everything 17 else has failed.
Joe?
18 MR. QUIRK:
Craig, I would like to make just a few 19 points.
20 The first one is that the three features that you 21 described before this one--combustion turbine, the AC 22 independent makeup pump, and the lower drywell flooder--those, 23 those are recommended by EPRI for future ALWRs, and as such we 24 are proposing those.
- )
25 This last feature is not recommended by EPRI.
From HERITAGE REPORTING CORPORATION -- (202)628-4888
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l
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1 a cost / benefit point of view, it cannot be justified for the.
}.
2 EPRI ALWR, and we agree with that.
Certainly, therefore, we 3
don't recommend it, and it is not appropriate for 4
consideration for existing plants.
5 However, this feature, if the ultimate event leading 6
to core failure is postulated, makes that event benign, and so 7
it's, it's looked at from that, from that perspective, and the 8
discussions are underway with the staff, and they are not 9
complete, and I just want to leave it at that stage with you 10 today.
11 MR. SCALETTI:
Point of clarification--we do agree 12 that discussions on containment failure evaluation of the
(
13 event are ongoing with the staff.
Discussion or definition of 14 containment failure is ongoing with the staff.
15 The sequence of events which Dr. Sawyer gave perhaps 16 are not totally correct.
The vent was offered in the initial 17 PRA submittal in early January.
The staff considers it to be 18 part of design.
The details of that design have not been 19 worked out.
It was not imposed by the staff.
20 That is not saying that eventually it might have if 21 GE hadn't offered it, but clearly it was offered by General 22 Electric, and it is in part of the design for the ABWR.
23 MR. SAWYER:
I agree with that.
The staff, the (f
24 staff did not impose this design on us, but the considerations 25 of how you define containment failure is what led up, is what HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 led us to this, this, basically thic option as being the way 2
to deal with that.
3 MR. QUIRK:
Correct me if I am wrong here, but Dino, 4
you said we offered this in our January PRA submittal, and the 5
context that we were talking about it there was as prevention 6
feature to enable passive decay heat removal prior to core 7
damage.
8 MR. bAWYER:
That is correct.
9 MR. QUIRK:
The context that we just--
10 MR. SAWYER:
This context is for a hardened vent 11 capable of basically handling overpressure of the containment 12 to avoid its failure.
13 In the January submit, you are right.
We took 14 credit in Station Blackout scenarios for the operation of 15 existing equipment, but it was in the ABWR already to remove 16 decay heat if you got to that point.
You are absolutely 17 right.
18 CHAIRMAN MICHELSON:
Well, I've heard some confusing 19 information here, and I would like to get it straight.
20 As I understand it, this is a part of the, of the 21 design.
We will review this pending feature of the design.
22 As far as the staff is concerned, it is now a part of the 23 design, is that correct?
()
24 MR. SCALETTI:
That is correct.
25 CHAIRMAN MICHELSON:
As far as GE is concerned, is HERITAGE REPORTING CORPORATION -- (202)628-4888
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'l that a part of the design?
2 MR. QUIRK:
Let me say it is not at this minute part l
l 3
of the ABWR design.
Now let me finish that, please.
We have l
4 offered it to the staff and will put it in the design if the l
5 staff gives.us credit for the benefits that we seek.
l 6
Otherwit>e there is no need to put it in, so we are 7
.saying we see these additional features as desirable, here is 8
the benefits we get from them, and if you agree, we will put 9
them in.
Okay.
The staff hasn't come back and said we agree.
10 CHAIRMAN MICHELSON:
At such time as the staff 11 writes their SER, it will be in one way or the other and then 12 see if there is a difference.
()
13 There may be a subtle difference--let me ask a 14 couple of questions.
Assuming--
15 MR. SAWYER:
It is not subtle.
Depending upon what 16 staff worries about, there is always, as you pointed out in 17 the critique, for example, what the offerings we have--you 18 never get any, something for nothing, okay.
There is a down 19 side to each one of these things that you might offer, and 20 our, our offer was contingent on the staff agreeing it did 21 good things.
22 CHAIRMAN MICHELSON:
Well, for the moment, I guess I 23 will have to assume thrit is a part of the design and ask yoe a
()
24 couple of questions as a part of the design so maybe you could 25 put your slide back up so we will get a couple of questions HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 answered and'we will get more later I suspect.
2 The ruptured disc shown, what do you intend the 3
rupture pressure'to be relative to containment design 4
pressure?
l 5
MR. SAWYER:
Containment design pressure is 45 6
pounds. gauge.
Our intent here is to design the ruptured discs 7
well over that, and we haven't--the number, of course, would 8
be definitely part of the negotiation between us and the 9
staff.
Our intent would be to pick a number somewhere around 10 80 pounds.
1?
CHAIRMAN MICHELSON:
The problem with the ruptured 12 disc aspect, of course, is if you want it, if you are getting 13 over 45, then everything was still not too bad, your option 14 obviously would be to start vent, then to keep the pressure 15 from getting any higher because you're guesstimating how the 16 containment might even fail.
17 MR. SAWYER:
There are other lanes that can be used 18 in the plant.
19 CHAIRMAN MICHELSON:
Is there ways of vent through 20 the dry, through the wetwell and removing energy that way 21 besides this proposal?
22 MR. SAWYER:
There are, there are ways, depending 23 upon the assessment by the plant staff.
They could lead to
()
24 local damage in the reactor building.
25 CHAIRMAN MICHELSON:
Unless described in the SER, or HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 in your, in the SSAR, I would assume there aren't any ways.
2 MR. SAWYER:
You can open--if what you are worried 3
about is inability to remove decay heat, among other things, 4
you can, you could choose to remove MSIVs, for example.
5 CHAIRMAN MICHELSON:
That depends on what, the 6
event, and you know, what power is available, how you can get 7
it out of the condenser and so forth.
8 MR. SAWYER:
I mean even at risk of blowing the 9
condenser, if it gets down to, if it gets down to a damage 10 control assessment for the, for the whole. plant, you decide 11 what to do.
12 CHAIRMAN MICHELSON:
I would suggest that if there
()
13 are easy ways to propose this, it would be certainly 14 beneficial to propose it in your documents just to, so we 15 could see that this is not really the last ditch, if there are 16 ways after you get over 45 pounds to do this.
Otherwise I 17 would question the ruptured disc because that means you have 18 got to wait until you get to that ultimate point before you 19 can even start venting, so it just, if there are ways, you 20 should expand on it.
21 MR. SAWYER:
There are ways.
I'm not sure I would 22 want to at this point proceduralize them.
We don't see any--I 23 understand your problem.
()
24 CHAIRMAN MICHELSON:
You can see my prchlem.
25 MR. SAWYER:
But let me respond by saying in the HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 risk evaluations we have done with these considerations, we 2
don't see, we don't see something that you are losing as a 3
result of waiting.
4 In other words, that because I chose to wait to 5
allow the containment pressure to increase before this 6
ruptured disc failed, that there, that that in itself caused 7
additional loss of capability in the plant.
8 CHAIRMAN MICHELSON:
Well, if you are confident that 9
the containment does not rupture until you get to 80 pounds, 10 then you are in good shape.
11 Let me ask a couple other questions.
I don't want 12 to dig into the details that far at this time.
The (3
\\_/
13 air-operated valves you show, are those failed close on loss 14 of air?
15 MR. SAWYER:
No.
Fail as--
j 16 CHAIRMAN MICHELSON:
But they are normally open?
17 MR. SAWYER:
Normally open.
18 CHAIRMAN MICHELSON:
I thought they were kind of i
19 there to make sure that if the ruptured disc ever 20 deteriorated, that you don't start blowing the containment l
21 right away.
i 22 MR. SAWYER:
No.
The rationale for them is 23 basically, is basically to put the operator in a mode of, of
()
24 recovery rather than in, than rather than in the direct act 25 of, of causing the opening.
l HERITAGE REPORTING CORPORATION -- (202)628-4888 l
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1 CHAIRMAN MICHELSON:
What are they actually in there 2
for then?
3 MR. SAWYER:
Isolation.
4 CHAIRMAN MICHELSON:
For what case?
5 MR. WARD:
Recovery.
6 CHAIRMAN MICHELSON:
After you think you have got 7
containment back and then you want to--
8 MR. SAWYER:
Want to close them.
9 CHAIRMAN MICHELSON:
Okay.
And now do you have air 10 to operate them at that point?
I guess you have shown somehow
.11 you dc.
12 MR. SAWYER:
Yes.
They would be powered off the
)
13 same dedicated air supply that we used for the ADF, so we will 14 have, we would have air for it.
15 CHAIRMAN MICHELSON:
It may be ADF air supply.
One 16 of their problems to begin with, but we won't get into that.
17 Let me ask, you show a connection of stack.
I l
18 assume that's hard pipe all the way to the stack.
19 MR. SAWYER:
Correct.
20 CHAIRMAN MICHELSON:
Is this going to be designed so 21 that you can relieve 80 pound gas?
This is what, an 8 inch 22 pipe or something?
23 MR. SAWYER:
That's being kicked around, too.
Right l
()
24 now, our, our thoughts on this are to design it to have the l
l 25 same capability as what the RHR system would have had had the l
l L
HERITAGE REPORTING CORPORATION -- (202)628-4888 t.
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1 RHR system been working.
l l
2 CHAIRMAN MICHELSON:
You don't have a feel for the
-3 size?
4 MR. SAWYER:
We--the size is probably more like to 5
14 inches.
It has got to handle a couple percent of decay 6
heat.
7 CHAIRMAN MICHELSON:
Ultimately this will have a 8
very large full capability, have 80 pounds--
9 MR. SAWYER:
Yes.
10 CHAIRMAN MICHELSON:
And does the stack blow up when 11 you try to push that much gas into that stack?
That has got 12 to be a real, real good stack, because it doesn't necessarily O) 13 have the pressure capability.
It is not an 80 pound or 14 hundred pound pressure stack partly.
It is a few. pounds at 15 best, so you have got to design the stack so that because a 16 discharge stack is where the pressure drop occurs, and it just 17 pressurizes the whole stack and it may fall apart, but maybe 18 that's okay.
I don't know.
But it is certainly something we 19 would ask you to look at, why the stack doesn't blow.
20 MR. QUIRK:
That is just before the--this ruptured 21 disc isn't going to operate until just before the ultimate 22 containment failure.
23 CHAIRMAN MICHELSON:
The ruptured disc isn't going
()
24 to open.
That's what prevents the containment--but whether or 25 not you want to have a stack failure, that depends on a lot of HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 things--on the, where the air intake control room, a whole lot V
2 of stuff which I don't know details off, but you would either, 3
you would either show stack failure is acceptable, or you 4
would show that the stack doesn't fail.
It would be a 5
question later.
6 MR. SAWYER:
Yes.
I think your comment is well 7
taken.
We, if we go the route of not, of not providing 8
sufficient pressure capability in the stack, then it is up to 9
us to prove that that failure in itself is okay.
10 CHAIRMAN MICHELSON:
Right.
11 MR. WARD:
How big is the stack?
I mean the 12 diameter?
O(_/
13 MR. SAWYER:
I don't know.
Do you know?
14 MR. MILLER:
What was the question?
15 MR. SAWYER:
What is the diameter of the stack?
Do 16 you know offhand?
17 M'.
MILLER:
No.
I wouldn't want to say.
18 MR. SAWYER:
Sorry.
I don't know the answer 19 offhand.
20 CHAIRMAN MICHELSON:
So far you show a rather small l
21 stack, but I wouldn't want to say the diameter.
It's a steel, 1
22 tin-type stack.
I don't know what its pressure capability is.
I l
23 Let's see.
Are you finished now I think with the
()
24 presentation, or do you have a little more?
25 MR. SAWYER:
I'm finished with the three topics, the i
HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 first three topics on the agenda this morning.
2 The next topic that I have is on, is I think--are we 3
ready to proceed to the left-over questions from last time?
4 MR. QUIRK:
Maybe this would be an appropriate time 5
for the break.
Let me ask the Chairman.
6 MR. WYLIE:
Has the Japanese run.a PRA on the plant 7
there?
8 MR. SAWYER:
Yes.
We have, we did a, a Level 1 PRA 9
about three or four years ago.
The Japanese are also doing 10 level three type PRAs for the Kasawaski 6 site.
11 MR. WYLIE:
Are the numbers similar to--
12 MR. SAWYER:
Their numbers are lower than ours
(
because they SCRAM once per five years these days, so their 13 14 initiating event frequencies are lower and so their numbers 15 are going to be better.
16 MR. WYLIE:
They are using their experience in their 17 PRA?
18 MR. SAWYER:
Yes, they are.
19 MR. WYLIE:
Much better; do you--let's see.
- Well, 20 do they have a three train system, or is it two?
21 MR. QUIRK:
It is three.
22 MR. SAWYER:
It is just like this.
23 MR. WYLIE:
Okay.
()
24 MR. WARD:
In the ABWR or Kasawaski?
25 MR. SAWYER:
Just a second; let me address that.
HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 They are not going to implement a gas turbine.
In their 2
rationale what they have is a pretty good one.
These two 3
units are the 6th and 7th units at a 7-unit site, and they 4.
have arranged their site network such that they have a lot of 5
capability for intertie of either generator output of other 6
units or emergency diesel output from other units, and so they 7
think they can meet requirement for on, or having a lot of 8
on-site power capability, in other ways.
9 MR. WYLIE:
That sounds reasonable.
It is the 10 intent if you get an order from U.S.
for this certified 11 design, that you would supply all U.S.
manufactured items, or 12 those by the Japanese in any part?
13 MR. SAWYER:
I think it is our intent we would go 14 out for competitive bid.
15 MR. WYLIE:
Worldwide or domestic?
16 MR. SAWYER:
It may turn out as to the state of the 17 U.S.
manufacturing capability in some key areas such as the 18 reactor vessel manufacturer, for example, it may turn out that 19 we procure equipment from Japan.
20 MR. WYLIE:
They are supplying their own valves?
21 MR. SAWYER:
Yes.
22 MR. WYLIE:
Not using Limitorque operators and l
23 Mitsubishi?
()
24 MR. SAWYER:
They basically have an indigenous 25 supply of almost everything.
Possible exception to that are HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 some, some computer type, process computer type hardware, or
.V) 2 neutron' monitoring equipment.
There are a few key high tech 3
areas where they still basically procure from, from us or 4
Canada.
5 MR. WYLIE:
So you would procure worldwide then on 6
the components of the plant?
7 MR. SAWYER:
Sure.
8 MR. WYLIE:
Okay.
Thank you.
9 CHAIRMAN MICHELSON:
Let's take a break until 10:30, 10 and then we will proceed.
11 (A brief recess was taken.)
12 MR. RUBENSTEIN:
My name is Les Rubenstein.
I'm the i
)
13 Assistant Director for Region IV and special projects on the 14 staff, and I would like to address a little bit about the 15 staff's position on severe accidents this morning.
16 This is essentially the, the same background 17 discussion that we had at the EPRI meeting, on the EPRI i
18 subcommittee at Palo Alto a few weeks ago, and it follows Dr.
19 Murley's discussion to the Full Committee on severe accident l
20 phenomena and design to accommodate those phenomena in the 21 ABWR which he gave a while ago.
l --
22 What I would like to do is trace the context of how 23 we got from the original Commission's policy statements on l
24 severe accidents and standardization and advanced reactor, l
()
l 25 advanced reactors, to where you are today, and give a little HET.ITAGE REPORTING CORPORATION -- (202)628-4888 j.
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insight to the staff's background and meetings on this.
1 2
This has been a large and involved and detailed 3
evolutionary process.
Basically our authority for dealing 4
with severe accidents for future designs flowed from the three 5
policy statements I just mentioned, and among other things, 6
they said in addition to addressing severe accident phenomena, 7
they said to meet the 5034 and 0737 TMI requirements, solve 8
medium and high priority generic issues, and do a PRA, and 9
consider enhancements to safety.
10 Well, after that, at about that time, the lead for 11 developing the severe accident policy requirements was placed 12 in Research, and a series of papers were delivered to the
()
13 Commission on implementation of severe accident policy for 14 evolutionary light water reactor designs, and concomitantly 15 with that, a series of public meetings were held, and at that 16 period, a year and a half or two ago, it was planned that two 17 severe accident rulemakings.
One would be conducted by the 18 Commission and perhaps result in additional guidance in two 19 regulatory guides.
20 As this process evolved, it became clear that EPRI 21 and the designers and the owners in industry were essentially 22 addressing most of the staff's concerns and the phenomena 23 which had been identified, and, and what we did was we
()
24 considered that additional requirements if needed could be 25 addres' sed by the staff, and as they would evolve through the HERITAGE REPORTING CORPORATION -- (202)628-4888
348 1
review process.
[
2 So as Research met with the public and the industry 3
in general, we worked with Research in their public meetings, 4
and it became clear through our earlier involvement in the 5
design review process that many of the features that were in 6
the thousand megawatt or the evolutionary designs would 7
address the phenomena.
8 We started to evolve to an NRR/Research position, 9
and the way we achieved that position is we went off and we 10 had two retreats.
We took the staff away to the Holiday Inn 11 at Crowne Plaza, and in the first retreat, we addressed not 12 the severe accident requirements, but the Commission's
/"
(_T
/
13 exhortation to consider enhancements to safety, ana i.' those 14 discussions, we evolved a number of items which were published 15 in SECY paper 89-013 last November, and tidied up within the 16 design basis some of those requirements.
I 17 Subsequently, we went off and we had a retreat in I
18 which Research presented the results of their contractors and l
19 their own thoughts.
The project managers who represented the 20 three designs before the Commission presented what the designs 1
21 were offering at that time, and then the NRR staff presented 22 their thoughts on the subject which synthesized on these two l
23 things, and it was agreed that at that time because of the
()
24 EPRI review, and the review going on with GE and Westinghouse, 25 that what we would do is probably write a staff paper saying HERITAGE REPORTING CORPORATION -- (202)628-4888 1
349
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1 this is what General Electric, who is probably in the arena at 2
this time, offered in the way of solutions to the severe 3
accident phenomena.
4 This paper was prepared, and on looking at it, it 5
became clear that there were very few things that the staf:!
I 6
were looking for that hadn't been offered, and it was our 7
decision at that time to accept it, recognizing that the 8
Commission had told us in their Statement of Considerations 9
and the discussions on Part 52 which incorporated and codified 10 some of these severe accident considerations, that if anything 11 arose that was special in terms of requirements, that you 12 should come to us and tell us about it.
(~s 13 At this time after the review, we don't see anything i
14 special that we have to go back and recommend for rulemaking, 15 so in effect, we are not in a position of meeting any 16 rulemaking at this time for severe accident requirements.
(
17 We have before us a body of items that General l
18 Electric has offered.
As of yesterday, Mr. Stello has signed l
19 our SECY paper which details in some more detail than, in 20 terms of scope than it was discussed to date, the severe l
I 21 accident design features of advanced boiling water reactor, l
22 for the ABWR, and we have furnished you a draft copy, and as 23 soon as we can, in the next day or two, we will furnish you a
( )-
24 formal copy.
25 In that time, at that paper, what we included were l
i l
1 l
HERITAGE REPORTING CORPORATION -- (202)628-4888
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(~)
1 some things that we may not discuss today, but which we wanted u
l 2
to tidy up.
We dealt with a couple of the precursors to the 3
major accidents which was the ATWS and Station Blackout items.
4 We discussed intersystem LOCA, which we think is 5
important.
We discussed hydrogen control, and I believe 6
before we got here we discussed that.
We discussed venting or 7
containment overpressure protection.
We discussed concrete 8
interaction and the ability to cool core debris.
9 We had some discussions of the source term and the 10 PRA that was to be done, and then we did a little tidying up 11 on areas of the BWR, We talked about thermal hydraulic 12 stability, and this sort of brings us up to where we are 13 today.
14 It was a fairly deliberate process which evolved 15 over the last few years.
As we see it today, it is a little 16 preliminary in the design to say that the particular features, 17 whether it is a 10 inch or 14 inch or an 8 inch vent which 18 will fully satisfy the equivalency of the RER or that is under 19 review, but over all, as we proceeded, we believed that the 20 phenomena are appropriately addressed.
We don't see any 21 phenomena that are leaking through that we should consider 22 that is not being addressed in the design, and we can talk 23 specifically about any one or all of these features in the
()
24 staff's preliminary review.
That is, today Mr. Fennern and i
25 staff are here.
They can answer questions.
If they are not l
I HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 here, we can answer it.
2 It is quite obvious that in terms of Station 3
Blackout, the GE design meets the main features of the Station 4
Blackout rule.
The EPRI requirement in terms of a gas turbine 5
goes beyond the alternate AC.
We would require explicid,1y a 6
minimum of an alternative be a different design diesel, but we 7
can go into some of those details.
They are here, and I would 8
entertain questions myself.
9 CHAIRMAN MICHELSON:
Let rue start of f by asking you, 10 under the venting portion, it talks about a hardened wetwell 11 vent capable of vent at pressures ur to approximately 80 12 pounds.
()
13 Should that mean that you had in mind that you could 14 select at what pressure you would start venting, depending on 15 the situation, or does it mean you simply didn't care, up to 16 80 pounds was okay?
17 MR. THADANI:
Dr. Michelson, I think that issue is 18 still open, and there are a lot of parameters that one has to 19 carefully consider before coming to that kind of a conclusion.
20 It seems to me one is the confidence in terms of 21 containment integrity.
That's one issue.
Other issues would j
22 be in fact things like time of the day, coordination with the 1
23 emergency planning evacuation capabilities, and so on.
I
()
24 don't think that's an easy answer.
I 25 CHAIRMAN MICHELSON:
But your intention was HERITAGE REPORTING CORPORATION -- (202)628-4888
352 1
depending on the situation, you may want to start venting at 2
60 pounds and not wait until 807 l
3 MR. THADANI:
That may be in fact the better thing I
4 to do, and so that issue has not been dealt with.
5 CHAIRMAN MICHELSON:
Okay, because the design we saw 6
today is kind of locked into one.
l 7
MR. RUBENSTEIN:
In fact, the design we saw at the 8
last meeting with GE, the ruptured disc is probably around 40 9
or 45 psi.
10 MR. WARD:
No.
He said it was--
11 CHAIRMAN MICHELSON:
He said the last discussion.
12
.MR.
RUBENSTEIN:
I want to show how fluid it is.
13 What you are getting is some very early deliberation.
14 CHAIRMAN MICHELSON:
I just want to make sure you're 15 not, that it is a selective process not locked into one.
16 MR. THADANI:
It is something one has to deal with 17 very carefully, and we haven't got there yet.
18 CHAIRMAN MICHELSON:
Okay.
19 MR. WARD:
Although on that point, the wording in 20 this draft paper would seem to--venting will require the use 21 of DC power and pneumatic pressure to open isolation valves.
22 Would that preclude depending on a ruptured disc as 23 GE seems to have proposed?
t h
24 MR. THADANI:
No, I don't believe so.
I think it 25 was a question of, it seems to me it was a question of the C*RITAGE REPORTING CORPORATION -- (202)628-4888
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capability of valves, being able to control those valves in
)
(}
2 the event that AC power is not available.
3 MR. RUBENSTEIN:
You would want to be able to stop 4
vent when you reached the appropriate pressure.
S' MR. THADANI:
If the language gives you that sense, 6
certainly we didn't mean that, to preclude the use of--
7 MR. SAWYER:
I think the intent is to get away.from 8
any reliance on AC power.
That was really the intent.
9 MR. THADANI:
That is really what we meant by that 10 language.
11 CHAIRMAN MICHELSON:
The way your language is 12 arranged, you say you probably did not even vent a ruptured
(
13 disc, although I guess you are saying you did.
14 MR. THADANI:
We did not exclude the use of ruptured 15 disc.
I think it is, it is--you have heard me say before on 16 the different class of plants, we would be concerned about 17 inadvertent use of this system as well.
I think it does 18 provide some protection.
19 CHAIRMAN MICHELSON:
Not having had time to read the 20 draft yet, it is a little harder for us to ask questions on 21 it.
22 MR. THADANI:
If I may just make a very brief, 23 general comment, I think while we don't have the details, but
()
24 we came at it from the perspective of body of knowledge that 25 has been developed up to now, and one of the key challenges to HERITAGE REPORTING CORPORATION -- (202)628-4888
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containment, and their ability to deal with those challenges,
[}
2 and what we did was we sort of went through a list of these 3
challenges starting with hydrogen control, what can one do to 4
deal with potential failure from hydrogen detonation and so 5
on, on down.
6 That was a thcught process we went through, and then 7
we said we would like to 1.'nd a way to assure that there 8
wouldn't be mechanisms, credible mechanisms that would lead to 9
relatively early containment failure, and so what you see in 10 front of you is a piece of paper that I hope deals with those 11 early challenges to containment, and then the other piece we 12 dealt with, and I think that sort of stopped on it, was the
()
13 sense that we would like to see enhancements in the future 14 evolutionary light water reactors, and where should those 15 improvements be focused?
16 I mean there are lots of places, but somehow one 17 needs to develop some focus, and what we did was to say okay, 18 we have learned a great deal from past studies and we selected 19 a lot of items.
Some of them were like ATWS has been 20 discussed.
Station Blackout hes been discussed.
Intersystem 21 LOCA, because of its potential for large releases, even though 2?
the likelihood may in fact be very low, it is still a cor.cern 23 for bypassing containment, was a consideration.
()
24 It was that kind of a thought process that led us 25 to, to look at specific areas to see how this advanced design HERITAGE REPORTING CORPORATION -- (202)628-4888
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was better than what we have today, and that's hopefully what Q
2 you see in this paper, and the earlier' November '88 paper.
1 i
f 3
MR. RUBENSTEIN:
Let me put it in a very broad l
l 4
context.
If you ask yourself what are the requirements to 5
license a thousand megawatt evolutionary plant, you have the l-6 existing basis of the rules and the regulations, and the SRP 1
7 which gives guidance in these areas.
8 You have the policy statements which say here is 9
what you have to do for severe accident, and these have been
.10 codified in Part 10, CFR Part 52, which also defines the 11 process on how to get a plant licensed for the future.
It 12 deals with early site permits, combined CPOL, and design
()
13 certification, so we incorporated and codified some of the 14 policy aspects that were in these early policy papers on 15 standardization, advanced reactors, and severe accidents into 16 Part 52.
We defined the process.
17 Then we asked ourselves okay, we have to go ahead 18 and give that set of information and needs for these future 19 plants that are not covered by these things, so in SECY paper 20 013, we listed a number more.
In the paper you have before
,21 you, the GE paper for the ABWR, we have those interactions.
I 22 don't think we have ever discussed within that the design 23 basis and the other auxiliary things that you are required to
()
24 do, and they include scope of design, 60-year life, fire 25 protection, tech specs, clearly going into design HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 certification, required fairly mature, well-defined tech 2
specs.
3 We have a statement on testing and maintenance.
We 4
talk about the industry use of the map and severe accident 5
phenomenological codes, which are very important to do PRAs.
6 We spoke early on about Station Blackout and electrical 7
systems.
We spoke about leak before break.
We gave our early 8
work on source terms.
We said we would take into account the 9
fact that containments would have decreasing pressure over 10 time, and we also discussed physical security, and the staff 11 also agreed that the OBG should not control the design of the 12 safety systems as now required by Appendix A.
We considered
()
13 this issue.
14 We talked about containment heat rates and hydrogen 15 generation, so back in November, we started mostly within the 16 design basis to set out those additional enhanced requirements 17 that were necessary to make a full and complete set for future 18 plant, and we think in the case of the ABWR today, recognizing 19 that the review process is well before us, much of it, and we 20 are still doing some of the EPRI work, but we think we have in 21 place a full set of enhancements and a way of dealing with 22 severe accidents, and the process which is defined in 10 CFR 23 Part 52 which will allow us to have a full set and have, take
()
24 a plant through the review process and get it certified, and 25 if there is an appropriate site in the United States and we HERITAGE REPORTING CORPORATION -- (202)628-4888
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want to deal with it, there is also a mechanism to do an early
-(
2 site permit review.
3 CHAIRMAN MICHELSON:
I was always a little puzzled 4
by the word enhancement in future plants.
You know, what do 5
we mean by an enhancement?
So I used the test case, the 6
security question, and I am still searching in my mind.
What 7
are we doing differently that we weren't already doing on our 8
present plants, including we are only considering the same 9
challenge to the plant, and it looks to me like the features 10 proposed are about those we already require.
11 MR. RUBENSTEIN:
Except that--
12 CHAIRMAN MICHELSON:
I am lost on the enhancement l
().
13 aspect.
14 MR. RUBENSTEIN:
Let's take one of */our favorites,
}..
I 15 fire protection.
16 CHAIRMAN MICHELSON: -Let's take security,.
The 17 subject that I was raising.
Fire protection we really haven't 18 heard yet, so I can't say for sure what they are doing.
I l
19 MR. RUBENSTEIN:
I will read it to you, sir.
20 Sabotage should be addressed in all future ALWR applications.
21 As a minimum, information should be provided to demonstrate 22 the existence of adequate physical barriers to protect fire 23 equipment in accordance with ten CFR 7355C and identity access l
()
24 control points to all vital areas in accordance with 10 CFR 25 7355B.
HERITAGE REPORTING CORPORATION -- (202)628-4888
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i
{}
1 Now many of the security vital areas were imposed 2
after the current generation of plants were built, and what we 1
3 are looking for and we are receiving I'll say candidly in the j
i 4
designs, it was for consideration that beyond controlled f
5 access and entry to certain areas, that it is just physically 6
difficult to get to two of the shutdown drains, just to 7
physically separate.
We are looking for well-defined vital 8
. areas which does this early in the design stage.
9 CHAIRMAN MICHELSON:
New plants mean present-day 10 plants, have that kind of physical--are you--
11 MR. RUBENSTEIN:
Well, they do.
12 CHAIRMAN MICHELSON:
In many cases, but some cases 13 don't, but I didn't detect any enhancement beyond the best 14 arrangements in today's plants.
That's the question.
15 MR. RUBENSTEIN:
I think you have to, you have to 16 get into the review on some of these, and see the layout.
l u
17 CHAIRMAN MICHELSON:
We did get into the review and 18 saw the layout.
They are not unlike many of the newer plants 19 today.
Certainly much different than the old plants, but that 20 isn't the issue.
I was just trying to say the enhancement 21 puzzled me because I didn't see the enhancements that I might 22 have perhaps thought would be there if we were really moving 23 forward and not just trying to maintain a status quo.
()
24 MR. RUBENSTEIN:
Well--
25 MR. THADANI:
I guess--did you mean in terms of HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 physical security, or you were talking in a broader sense?
2 CHAIRMAN MICHELSON:
No.
Physical security was the-3 subject.
4 MR. THADANI:
Okay.
I hope you didn't mean it in 5
the broader sense.
6 CHAIRMAN MICHELSON:
What broader sense did you have 7
in mind?
8 MR. THADANI:
Well, I guess I was--it seems to me 9
that there are several areas where we are quite satisfied with 10 things as they are, and it is, our intent clearly was not to 11 test each aspect so to speak.
12 CHAIRMAN MICHELSON:
The intent is apparently to use
()
13 the same threat as we use today, for instance?
14 MR. THADANI:
Yes.
15 CHAIRMAN MICHELSON:
No new threats; the old 16 threats, whatever they were, are still to apply in the future?
l 17 That was the intent, and then we looked to see what provisions l
l 18 c.re in the plant to tighten things up and we see provisions 19 that are well ahead of cid plants, but not necessarily well l
20 ahead of the present-day plants, so enhancement to me means 21 something better than I have got today.
I don't see it.
I 22 MR. RUBENSTEIN:
Well, let me--
23 MR. MICHELSON:
We aren't going into any detail,
()
24 either.
25 MR. RUBENSTEIN:
If you look at the total of the HERITAGE REPORTING CORPORATION -- (202)628-4888
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items which we looked at for enhancement, and recognize this
%)
2 is the thousand megawatt evolutionary plant, and these severe 3-accident items and the enhancements are limited to that, and I 4
think what you will see in the 600 megawatt plants that are 5
being offered by the General Electric and Westinghouse and 6
possibly Combustion, are these dramatic improvements, even 7
though these could be described as built on evolutionary 8
technology.
9 It is there where you get into replacement for the 10 RHR by a passive system with passive water contained in 11 containment or passive cooling of the containment above it, 12 where there is no need perhaps for, at all fer an emergency 13 diesel generator, so in that sense, if you are looking for the 14 dramatic steps, they will be in the next generation.
The 15 thousand megawatts are more evolutionary in that sense.
16 CHAIRMAN MICHELSON:
We are looking at the thousand 17 megawatts, of course.
l 18 MR. RUBENSTEIN:
Right, but--
19 CHAIRMAN MICHELSON:
And I don't find them more 20 evolutionary at least in the example I gave and some of the 21 other examples.
I don't know yet.
We haven't seen fire 22 protection in any detail yet, so I don't know, but it is 23 entirely possible there may be, indeed be enhancements.
(
()
24 MR. RUBENSTEIN:
The main enhancement if I can 25 generalize it on fire protection is clearly that we are not l
l HERITAGE REPORTING CORPORATION -- (202)628-4888 t
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using Appendix R as a guide,.and as you have pointed out to us
~}.
2 quite often, that was a backfit for existing plants, and we 3
are now moving toward fire barriers which, to the five areas, 4
which will allow you to shut down the plant independently of 5
losing an entire fire area, and this is a fairly good, strong 6
report, particularly when one takes into account we mean about 7
three-hour fire barriers and separation, with some-8 consideration given for difficulty in achieving this within 9
the containment and the reduction of the kind of gathering 10 together of the cable rooms and other areas, and with some 11 improvements in the control room, so I think we and the 12 industry have taken to heart that we want to go forward in 1
()
13 that area.
14 I think even more so we are getting into the testing 15 and maintenance, and having the tech specs well defined up 16 front, so I think in total, or cumulatively, we have got a 17 fair number of enhancements.
We may not have gone as far as l
18 individuals would like in certain given areas, but I think 19 cumulatively within the design basis they are better and they 20 are clearly a lot better in addressing severe accidents 21 overall.
i l
22 CHAIRMAN MICHELSON:
But the comment was originally 1
23 directed to what did you mean by enhancements, and I guess you 24 are still saying it means the over and above what we do today i
()
25 on the best plants we built.
l HERITAGE REPORTING CORPORATION -- (202)628-4888 l
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1 MR. RUBENSTEIN:
That's true.
%/
2 CHAIRMAN MICHELSON:
That's what I look for.
What 3
are we doing differently, better, beyond what we are doing 4
today?
And in some places I see enhancements, and some 5
places, I'm not sure I ree enhancements.
6 MR. RUBENSTEIN:
That's true.
There are a lot of 7
areas we haven't dressed.
8 MR. MICHELSON:
They are addressed in areas we think 9
we have addressed as enhancements, and that may be 10 argumentative.
11 MR. THADANI:
I think the example you used, that's a 12 pretty fair comment.
13 CHAIRMAN MICHELSON:
I think that's the worst case 14 where we seem to have done the least enhancing if indeed we 15 have enhanced at all, yes, but other areas, clearly I hope 16 fire protection is greatly enhanced, but we haven't had a l
17 chance yet to get to the details of that to see if indeed that 18 is the case.
19 Is security not an item addressed in this proposed 20 Commission paper?
I notice Station Blackout and intersystem 1
22 MR. RUBENSTEIN:
Security was addressed in, in the 23 November paper.
-( )
24 CHAIRMAN MICHELSON:
It was in the November 1,
- yes, 25 but this is, this is to--
l HERITAGE REPORTING CORPORATION -- (202)628-4888
1 MR. RUBENSTEIN:
This is specialized to severe 2
accidents.
3 CHAIRMAN MICHELSON:
Yes.
It is not thought somehow 4
to be an initiator of a severe accident I guess.
That's how l
5 you might get into a severe accident, for instance, is by an 6
act of sabotage.
7 MR. RUBENSTEIN:
It is really dealing more with the 8
mitigational aspect, although we did go back and pick up some 9
more detail on Station Blackout and ATWS and intersystem LOCA, 10 so we, it is not--
11 CHAIRMAN MICHELSON:
I was looking at the title.
12 The subject of this is supposed to be severe accident design 13 features, and I thought those were features that would handle 14 a severe accident, depending on how you got into it, or i5 perhaps even helped to, to prevent the severe accident 16 situation.
17 MR. RUBENSTEIN:
Mostly mitigational.
This is our 18 first opportunity to deal with that, but I do want to make 19 clear we picked up a few miscellaneous pieces like stability, 20 but we also tried to address, enunciate our policy a little 21 better on a couple of the major initiators like ATWSs and 22 Station Blackout.
23 CHAIRMAN MICHELSON:
We had a little question in our O
24 Subcommittee meeting about ATWSs as to how fast the boron 25 injection was really going to be, but I think GE is going to HERITAGE REPORTING CORPORATION -- (202)628-4888
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clear that up for us sometime today., and I assume that is 2
indeed an ATWS mitigator.
In the high pressure--
3 MR. THADANI:
That's an issue that is still open, 4
and GE is evaluating it.
PerhAps we will hear something.
5 MR. QUIRK:
We were visiting.
You asked the 6
question--
7 CEAIRMAN MICHELSON:
I was going to say were you 8
going to clarify for us sometime today the ATWS situation and 9
whether the, you know, your injection system is an ATWS 10 mitigator or not?
There was a request about two and a half 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> for ATWS.
Did you ever get a clarification of the 12 timing of that system?
13 MR. SAWYER:
The timing, you were told yesterday 14 about the, about the time to get all the boron in is correct.
15 Now we haven't, because SRPs didn't require it, we didn't do n 16 specific analysis, staff review under Chapter 15.
17 Nonetheless, we have done evaluations of the l
18 degraded SCRAM capability starting from the ARI works to the 19 FMCRD electric run-in works to both SLC works and one SLC 20 works, and those cases have all demonstrated that the concern, 21 of course, when jou get down to using just the boron 22 injection, is what happens to the containment heat storage 23 capability at that point or isolation type transients?
And
()
24 our evaluation shows that we keep the containment within the 25 denign basis even if we get to where there is only injection HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 with one pump.
2 CHAIRMAN MICHELSON:
Two and a half hours was one 3
pump?
4 MR. SAWYER:
Yes.
This is with one pump.
5 CHAIRMAN MICHELSON:
Well, I assume that somewhere 6
in the staff SER, they will evaluate ATWS and they will show 7
two and a half hours is fast enough.
8 MR. THADANI:
- Yes, In fact we will, but I might 9
point out that the regulation 5062 would require that there be 10 not only stand-by liquid control system, but that it be 11 automatically actuated.
That was not required for older 12 operating reactors, but it was required for plants that got
()
13 licensed after a certain date, and that's as far as I know, j
14 and Limerick was caught in that situation where they do have 15 automatic SLCS, and yes indeed, we would look at this very 16 carefully.
17 CHAIRMAN MICHELSON:
We were wondering since it 18 seemed to be a very slow system compared to the ones we are 19 used to seeing, we wondered if it was still fast enough, and I 20 would expect to read about that in an SER, 21 MR. THADANI:
And we expect to look at it carefully.
22 MR. SAWYER:
I'm not sure where the observation is 23 the APWR SLC capability is slower.
My understanding of the
()
24 existing plants is that they have a, basically two SLC pumps, 25 each of which is capable of injecting about 43 GPM, and with HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 both of-them injecting simultaneously, double that.
2 The ABWR has two 50 GPM pumps, a slightly larger l
3 system, so in terms of, you know, in terms of that comparison, 4
I can't see why you would draw the conclusion the ABWR is much 5
slower.
6 CHAIRMAN MICHELSON:
Well, if your numbers are all 7
indeed correct, I thought that they were somewhat higher j
8 injection rates than 43 GPM.
9 At any rate, the staff SER will look at it and tell 10 us it is okay, and I don't care if it is ten hours if it is 11 shown by evaluation to be adequate.
12 MR. WARD:
I guess they test two and a half hours to 13 get it all in.
14 CHAIRMAN MICHELSON:
That was it.
It was 90,000.
15 MR. SAWYER:
Far less than that to get--
16 CHAIRMAN MICHELSON:
That's the key.
How long, how 17 much does to take to turn it around?
And that was, I was 18 thinking it was faster than 43 GPM, but I'm wrong on many 19 things and I probably am wrong on this one, but at any rate, 20 there will be an evaluation on that because we don't have the 21 time to go into all the numbers.
I was hoping, of course, you 22 would have given me an answer like that as soon as I asked the 23 question yesterday.
()
24 MR. SAWYER:
Sorry.
I just arrived today.
25 CHAIRMAN MICHELSON:
Well, you, I mean General HERITAGE REPORTING CORPORATION -- (202)628-4888 4
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1 Electric, of course.
l l
2 Does the Subcommittee have any other quick 3
questions in view of the recent receipt of this document?
4 MR. WYLIE:
It seems to follow pretty much what we 5
have heard from General Electric Company over the last two 6
days in a lot of respects.
7 MR. THADANI:
In fact the letter or the memorandum 8
that you have in front of you is cast that way as well.
9 CHAIRMAN MICHELSON:
We haven't had a chance to look 10 at the PRA yet, of course.
We heard just a little bit about 11 it this morning.
We will make it the subject of a special 12 meeting at an appropriate time, and we will-get into the 13 details.
14 MR. THADANI:
Yes.
And we haven't got very far, 15 either.
16 CHAIRMAN MICHELSON:
Do you, are you doing the work 17 on reviewing their PRA?
l 18 MR. THADANI:
We have Research staff and some NRR 19 participation and some help from Brookhaven.
20 MR. MICHELSON:
Do you have an approximate idea of l
1 21 when you think you will be able to talk about it?
22 MR. SCALETTI:
The SER for the, which covers the
)
i I
23 PRA, is scheduled to be issued in January of 1990, so whether j
()
24 we will be ready to discuss this in advance of that, it is 25 questionable.
We would have to see--
l
)
l j
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1 CHAIRMAN MICHELSON:
It doesn't seem like it is 2
going to be much use of getting anything other than an 3
overview of it for a few months.
We were thinking of getting 4
an overview to see how it is headed and get a feel for it, but 5
in terms of substantive comment, it looks like it is the end 6
of the year or later.
7 MR. SCALETTI:
Clearly GE would be I'm sure willing 8
to give you an overview on the PRA any time you wanted to, and 9
if the staff has progressed to a point where they have an 10 opinion, it is--they will be able to draw conclusion, they 11 would discuss it with you also.
12 CHAIRMAN MICHELSON:
A real review of it by our PRA 13 Subcommittee, for instance, ought to be early next year then?
14 MR. SCALETTI:
You will not see the SER until--
15 CHAIRMAN MICHELSON:
January '90 for the PRA.
16 MR. WARD:
I don't see why we couldn't review it, 17 you know, review what GE has developed sooner than that.
18 CHAIRMAN MICHELSON:
You can't ask the staff.
We 19 can ask GE, and that's all we can review, but to get the staff i
20 input to write a letter on it would require--
21 MR. THADANI:
And the staff certainly would be happy 22 to, to meet with you and give you our sense of where we are, 23 and in fact we would be quite interested in your reactions and
()
24 views, and I don't, I don't really see why we have to wait 25 until we are finished our evaluation.
\\-
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MR. WARD:
Carl, I would sure vote for doing
(
2 something obviously sooner than that.
3 CHAIRMAN MICHELSON:
That's what I meant by 4
overview, having a meeting to write a letter.
It appears that 5
the letter would be sometime off.
6 I guess we are going to write off yet on a time.
7 Looking at the SER that you supply, are they going to have a 8
caveat concerning the PRA?
9 MR. SCALETTI:
Each of the modules, eech SER 10 certainly will identify what is to come, and it can have a 11 caveat with the understanding that it is not the final SER.
12 There is still more to come and the final staff decisions and
)
conclusion aren't going to be presented until the January 13 14
'timeframe, and then even in the July of 1990 safety 15 evaluation, which wraps everything up, the final conclusion 16 won't come forth until then, but clearly the, I don't see a 17 need to caveat each SER with, with, to a finished product.
18 CHAIRMAN MICHELSON:
Just an overall caveat that 19 says that if we find out, we learn more later about that, we 20 may have to go back and comment.
21 MR. SCALETTI:
In the first safety evaluation, 22 probably in a subsequent one, we will define the review 23 process and how we are undertaking this review, yes.
()
24 CHAIRMAN MICHELSON:
This is once kind of defined I 25 thought, though, as a sort of a, you know, when we agree we 1
E-_--
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are on Module 1, we don't go back to Module 1 unless some new 2
real significant evidence shows up.
It sounds like this may l
3 be just slightly looser than that.
4 MR. SCALETTI:
Well, I think that's the intent.
~
5 What I intend to put out is final safety evaluations on each 6
group of modules.
Clearly they'will have outstanding issues 7
in them which would have to be addressed in future modules, 8
future safety evaluations, but hopefully--I don't see a reason 9
to go back and to re-address issues unless there is a, a
10 significant reason to do so.
11 CHAIRMAN MICHELSON:
Unless you find out from the 12 PRA that there are issues.ad you haven't even addressed them 13 yet.
14 MR. SCALETTI:
Clearly, clearly.
15 CHAIRMAN MICHELSON:
And that's what I was concerned 16 about.
17 MR. SCALETTI:
Absolutely.
18 CHAIRMAN MICHELSON:
I have no problem with doing 19 that.
20 MR. THADANI:
I just wanted to add one comment, and 21 this is really in response to I think what General Electric 22 said earlier.
23 On the issue of containment overpressure protection,
()
24 I have a very firm view that when you are looking at severe 25 accidents and the PRA and so on, we ought to do that as HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 realistically as we can because it is in fact the expected 2
response that we are after, and in that regard, systems such i
3 as the one that GE discussed early this morning, and its role l
4 in dealing with a given severe accident, are to be considered 5
and there is no question that if it is valuable, it is useful, 6
it reduces risk and so on, credit ought to be given for that 7
system.
8 I was a little bit surprised at the statement, so I 9
would like to assure GE that in our severe accident
~10 considerations, we look at whatever is there to see what value 11
.that might have to give, and I think in that regard, as the 12 result of that activity, if we do find something different
('
\\
13 that we may have overlooked, an individual module, certainly 14.
we will pick it up.
15 MR. WARD:
Okay.
I guess I don't really understand 16 the nature of that controversy, and but when, I--maybe I ought 17 to be addressing this to GE, but when credit is not given, I 18 don't understand what that means.
What is the credit?
Is 19 there some tradeoffs there?
20 MR. THADANI:
I guess where I was coming from was in 21 the licensing review basis document, Gene 231 Electric had 22 proposed three elements that it would consider, and Craig 23 Sawyer talked about, talked about that, and it seems to me it
()
24 is a pretty good setup.
It seems logical, sensible, and 25 presumably plays some part in making sure that we are, they HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 are better than those guidelines that GE has proposed, and I 2
don't really see why we would deal with the containment 3
overpressure protection system differently than we would deal 4
with the flooders, for example, or, for example, any other 5
system as far as I am concerned,_for severe accident 6
evaluations.
7 MR. RUBENSTEIN:
General electric has to deal with 8
many interfaces.
They have to deal with the staff.
They have 9
to deal with their customers, and they have to deal with the 10 industry groups who are also developing the severe accident 11 requirements.
12 I think the issue between General Electric and the
/n d )'
13 staff is we both see the value of overpressure protection, and s
14 the benefits.
15 CHAIRMAN MICHELSON:
If I understand this draft 16 correctly, this is a sort of a supplement to the previous 17 letter.
Everything in there is, still pertains--just some 18 more.
[
19 MR. RUBENSTEIN:
Yes.
What I meant to say before 20 was with the existing body of regulations, Part 52, the 21 enhancement letter, and this severe accidents, I think there 22 is a full set of clearly articulated necessities to get a 23 license for a thousand megawatt plant.
()
24 CHAIRMAN MICHELSON:
When this process first 25 started, there was considerable talk about these--I forgot HERITAGE REPORTING CORPORATION -- (202)628-4888
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what the term that you used was, but in essence it was as you 2
come to certain kinds of basic issues maybe like severe 3
accidents, you were goi) to do a licensing, some kind of a 4
licensing basis agreement on each one of these or something.
5 MR. RUBENSTEIN:
Yes.
6 CHAIRMAN MICHELSON:
What is the status?
Repeat 7
what it was and how is that coming along?
What is covered so 8
far?
9 MR. RUBENSTEIN:
In the case of General Electric, 10 they and the Commission clearly wrote out before the onset of 11 the review process a licensing review basis, and we both 12 signed to that, and that included the schedule and the process
()
13 of which, by which the review would be done, and it included 14
-some very significant design guidelines.
15 CHAIRMAN MICHELSON:
That is still part of the 16 requirements package?
17 MR. RUBENSTEIN:
Yes.
That's what Dr. Sawyer and 18 Mr. Fennern alluded to when they spoke about the public safety 19 goal of ten to the minus 6, 20 CHAIRMAN MICHELSON:
As I recall, it was a rather 21 general 1:ind of document.
It identified certain areas where 22 things would be done, but the details--
23 MR. RUBENSTEIN:
Here--and this, it got fairly
(^T 24 specific like conditional containment failure probability,
%/
25 and--
HERITAGE REPORTING CORPORATION -- (202)628-48P8
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CHAIRMAN MICHELSON:
What I'm really asking is what U
2 happened to, what has gone on since?
3 MR. RUBENSTEIN:
I started to say in the case of GE, 4
it was well done, done well in advance.
5 In the case'of Westinghouse, it is their intention 6
to provide an equal and similar comprehensive licensing review 7
basis right after the PDA which we expect very late this 8
summer on the SB 90.
9 Similarly, we have had three drafts from Combustion 10 Engineering for the System 80 Plus, and we have been in 11 detailed negotiations over what the content should be.
12 I might add that because we have gone away'from a (w) 13 single rulemaking for severe accident phenomena, we will 14 publish an equal SECY paper when the Westinghouse and 15 Combustion reviews are mature enough, and at that time, we 16 will make a decision whether this would be necessary to have 17 any additional severe accident requirements, or whether they 18 have in fact in their designs been forthright in addressing 19 the phenomena that we are seeing today.
20 CHAIRMAN MICHELSON:
Well, I don't know that you 21 have answered my question.
Let me ask it again a o2ightly 22 different way.
23 As I recall, the licensing review basis letter 24 covered more than severe accidents.
Was that correct?
[}
25 MR. RUBENSTEIN:
Yes.
It deals with the cost of the HERITAGE REPORTING CORPORATION -- (202)628-4888 J
375 L'
r~s 1
review, the time period which would encompass some of the
(_)
2 design goals, and all the details of how the review would be 3
done.
4 CHAIRMAN MICHELSON:
As I recall, the document said 5
as you come to each of these issue resolution so to speak, you 6
issue a letter or something, a document which described how 7
you resolved the issue for licensing purposes.
Was that something I dreamed up?
9 MR. RUBENSTEIN:
I don't recall that.
Perhaps Mr.
10 Scaletti--
11 CHAIRMAN MICHELSON:
Reached, as you reach 12 resolution, you documented the resolution.
o
(_)
13 MR. SCALETTI:
Yes, indeed, through the development 14 of the SER.
15 CHAIRMAN MICHELSON:
You don't document it as any 16 special letter, but rather just I will see it as a paragraph 17 somewhere in the SER.
18 MR. SCALETTI:
You might be thinking of the ARSAP 19 program.
20 CHAIRMAN MICHELSON:
You are in the process now of, 21 I'm sure of negotiating a number of these areas as we come 22 across these chapters, but the first I really know of that 23 resolution is in the SER?
~T 24 MR. SCALETTI:
That is correct.
(G 25 MR. RUBENSTEIN:
Yes.
l HERITAGE REPORTING CORPORATION -- (202)628-4888
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CHAIRMAN MICHELSON:
That's why I haven't seen them, 2
and I have been kind of lookil.g for them, and I wonder, and I i
3 see--I thought you were going to document them as a, as an 4
individual letter, report--here is how we settle on fire and 5
here is how we settle on this.
Here is how we settle on that.
6 MR. RUBENSTEIN:
No, no.
7 CHAIRMAN MICHELSON:
Okay.
8 MR. RUBENSTEIN:
The LRB, the licensing review basis 9
was here is how we are going to do it, but I add to that it 10 had never been previously well defined as in the case of 11 severe accident.
As you see a SECY paper for General Electric 12 dealing with severe accidents, you can see a SECY paper
(
13 dealing with Combustion and Westinghouse, recognizing that wi 14 are also doing the same kind of negotiation process with EPR1 15 in Chapter 5, which deals with much of the same issues.
16 CHAIRMAN MICHELSON:
How are you documenting that 17 process?
18 MR. RUBENSTEIN:
I have a draft SER for Chapter 5.
19 CHAIRMAN MICHELSON:
I will go back and read that 20 old license review basis.
I don't know why, but I was perhaps 21 just not reading very carefully, but I sort of thought I had 22 been led to believe I would see some documentation as we went 23 along and not at the end of the game, but I guess that was f( )
24 just ry poor reading.
25 It says words to the effect and will be documented.
HERITAGE REPORTING CORPORATION -- (202)628-4888
l 377 (j
(
1 I thought that.means people write it down and I could. read it, 2
but not at the end of the game.
I could read it as we went 3
along.
4 MR. RUBENSTEIN:
The evolution of--then I will come back to severe accident again.
The evolution of severe 6
accident is very complex.
The staff at one time with Research 7
was going along looking at optimization issues that EPRI had 8
proposed simultaneously with the successor program to--the 9
ARSAP program, and all of these fed into our general body of 10 knowledge, and got focused ultimately on what the individual 11 designers proposed and what we responded to in the SECY paper 1
12 we handed out today.
I didn't--
l
()
13 CHAIRMAN MICHELSON:
Severe accident you see is not 14 one of the issues I am raising.
I think you have documented 15 it the way I thought things were going to be documented.
I am 16 read $ng it as I go along.
17 MR. RUBENSTEIN:
We didn't.
We never responded 18 formally to the topic papers that EPRI proposed, for example, 19 this is the way to deal with hydrogen.
This is the way to 20 deal with core flooding or core basis of that interaction.
We 21 never dealt with them on the topic individual basis, j
22 We are now dealing with them in the course of the 23 design reviews, and that's what I meant when I said we didn't j}
24 deal with the ARSAP. topic papers.
We are not dealing with the 25 optimization papers from EPRI for the most part, although we HERITAGE REPORTING CORPORATION -- (202)628-4888
378 1
may do it on an individual basis, but what we are doing is 2
take all that information, that dialogue that has been going 3
on for the last five or six years, and focusing them into the 4
individual reviews.
5 CHAIRMAN MICHELSON:
That's the way we have always 6
done it I think, isn't it?
I thought this was going to be a 7
little different.
That's all right.
8 Wasn't there in the licensing review basis letter a 9
discussion of the concept of topic papers?
Wasn't that where 10 I read it?
That was not there in the optimi7ation papers?
11 MR. SCALETTI:
No.
That is not in the licensing 12 review basis for General Electric.
fh
(_j 13 CHAIRMAN MICHELSON:
It was in the EPRI?
14 MR. RUBENSTEIN:
Yes, the optimization paper.
15 CHAIRMAN MICHELSON:
The letter didn't refer to any 16 papers as such?
17 MR. RUBENSTEIN:
No.
18 CHAIRMAN MICHELSON:
Now that I'm put straight, I 19 think I can follow what you are doing and ask different kind 20 of questions next time.
21 Any other Subcommittee questions on the draft that l
22 we have in front of us?
At least I see none at this time, but 23 that is partly because it has to mature a little bit.
24 MR. RUBENSTEIN:
As you notice, in the back we
()
25 mentioned to the Commission that we would be supplying you HERITAGE REPORTING CORPORATION -- (202)628-4888
379
-[ }
1 with this paper, and they may perhaps elicit your views on 2
this subject.
3 CHAIRMAN MICHELSON:
Yes.
We really haven't been 4
briefed on the paper since we got it simultaneous with your 5
being-here.
6 MR. RUBENSTEIN:
We appreciate that.
We were 7
waiting to get it signed for about three days.
8 MR. WARD:
This is kind of maybe a little bit of an 9
overstatement.
10 CHAIRMAN MICHELSON:
Little bit.
11 MR. WARD:
Well, we are going to talk later about 12 what we want to have the Full Committee hear?
O
/.
(_/
13 CHAIRMAN MICHELSON:
Right.
I certainly think the 14 Full Committee would probably want to hear about this.
By 15 that time, we may become a little better prepared to ask 16 further questions, but that usually is not the place we try to 17 go into much detail.
18 I guess I see no other questions on this subject.
I 19 believe that, that takes care of I guess all the staff wanted 20 to talk about today then?
21 MR. RUBENSTEIN:
That is correct.
22 CHAIRMAN MICHELSON:
Maybe.before we let you go, you 23 could just tell us a little bit about the, the SER schedule
()
24 since it is beginning to slip a little bit, and our original 25 agreement with the staff was that we would certainly assure HERTTAGE REPORTING CORPORATION -- (202)628-4888
380 1
you that within two months of getting a document, we would, we 2.
would hold a Subcommittee meeting and that the Full Committee 3
would write a letter at the ' irst meeting thereaf ter.
t 4
That is still our intent, but as your material slips 5
and their schedule will slip, we will try to make up for part 6
of your slippage, but we can make no assurances because there' 7
are so many other factors, but it does appear like if we get 8
your SER in June like it appears now, then we will review it, 9
we will have a Subcommittee meeting in August and Full 10 Committee in September.
That appears to be, unless after 11 looking at it, if it looks like the Subcommittee thinks it 12 can have a meeting earlier than August, we will try to hold (f
13 one earlier.
14 MR, SCALETTI:
We would appreciate that.
And be 15 aware that it may include some safety evaluations that were 16 not previously scheduled in the first one.
17 CHAIRMAN MICHELSON:
Would that be chapters, though, 18 that you already had a couple of shots at, or the first time?
19 MR. SCALETTI:
Yes, I believe so.
20 CHAIRMAN MICHELSON:
If it is something we heard 21 once--
22 MR. SCALETTI:
I intend to include the Chapter 17 23 evaluation because we spent a great deal of time doing that O
24 review.
(ul 25 CHAIRMAN MICHELSON:
What is in Chapter 17?
l HERITAGE REPORTING CORPORATION -- (202)628-4888
381.
1 1
MR. SCALETTI:
Quality assurance; you' heard that 2
yesterday, so I would intend at least to include that in the 3
next safety evaluation.
4 CHAIRMAN MICHELSON:
I don't think that would be an 5
undue position.
We might have to spend a little of our time 6
asking questions about it, but no more than we would on the 7
other chapters I think we have probably seen in an adequate 8
fashion already, but we will try to fit in whatever you send 9
us as quickly as we can, and certainly it will be no sooner 10 than July.
It is just not practical since you are coing to 11 get it to us in June sometime.
12 MR. SCALETTI:
I understand.
13 CHAIRMAN MICHELSON:
Yep, so we will, we will see if 14
-we can.
Otherwise, clearly we are scheduled for August, and a 15 September letter.
16 I believe I see no other questions for the staff at 17 this time on what we have heard so far?
The SER is really the 18 big thing we need to see before we can ask further questions 19 on the early material.
I think the review in general is going 20 quite well.
I think that GE has made good presentations and f
21 the staff has supported it to the extent that you feel is l.
22 necessary, and the real, the real heat on you comes when we 23 read your SER, because that's the part, that's the part we 24 write the letter on.
And so far, I think we are doing fine.
25 Seeing no other comments then, we will consider your f
f HERITAGE REPORTING CORPORATION -- (202)628-4888
[
382
}
1 part completed.
2 MR. SCALETTI:
Thank you.
3 CHAIRMAN tIICHELSON:
We have--what would GE like to 4
propose to pick up at this time since we do have about a half 5
an hour yet this morning to either start a new subject or pick 6
up some of your miscellaneous leftovers?
7 MR. QUIRK:
What I would propose, we have a 8
carry-over question from the last meeting which had to do with 9
reactor vessel overfill.
10 CHAIRMAN MICHELSON:
That's a good one.
11 MR. QUIRK:
We also have a question from, carry-over 12 question from the last meeting that we we e to cddress 13 yesterday but didn't have time.
14 CHAIRMAN MICHELSON:
What was this?
15 MR. QUIRK:
That had to do with SRB temperature.
16 That carried over from the last meeting.
We are prepared to 17 deal with it.
We were supposed to deal with it yesterday.
We 18 ran out of time.
We could do that here.
i 19 CHAIRMAN MICHELSON:
How long do you think that one l
20 will take?
21 MR. QUIRK:
That's a ten-minute thing.
22 CHAIRMAN MICHELSON:
The other is 30 minutes?
23 MR. QUIRK:
About ten minutes.
()
24 CHAIRMAN MICHELSON:
Let's start with the vessel l
l 25 overfill, which is the most important, and if time permits, we L
HERITAGE REPORTING CORPORATION -- (202)628-4888
383 1
will-go into the other one, and that will be noontime.
Okay?
/'}
(-
3 MR. SAWYER:
Are we ready?
3 CHAIRMAN MICHELSON:
I think so.
4 MR. SAWYER:
Okay.
I am Craig Sawyer again talking 5
about the topic of vessel overfill.
I wasn't party to the 6
discussion that, at the previous meeting, so perhaps what I 7
have responded to doesn't exactly address what your concern 8
was, but let me give it a shot.
9 As you know, this issue has been on the table for 10 quite a while, and in fact, there was a huge study done on 11 this after TMI by the BWR Owners Group as to whether or not 12 there is a significant probability of having vessel overfill
()
13 while the vessel is at high pressure.
14 One of the recommendations--two things that were 15 observed out of that, out of that study.
One was it was 16 believed to be a low probability event, that is to say, about l
17 the same order of magnitude as getting a LOCA in the first i
18 place.
19 However, they did identify improvements in trip 20 logic, the various systems that, for high pressure injection 21 systems, that could be made, and to our knowledge, virtually l
22 all of the BWRs have subscribed to that with a couple of 1
23 exceptions.
All of the modern BWRs at least have subscribed
()
'24 to those logic improvements.
25 In the case of the ABWR, we have gone even further, HERITAGE REPORTING CORPORATION -- (202)628-4888 i
384 i
1 and the table I have presented on this chart shows the
(
2 improvements that we have made in that trip logic, 3
What I have listed is the, the systems that, that 4
can deliver significant high pressure water, what the logic l
5 is, and then some commentary, and let me go over each one of 6
them.
7 I guess the, I guess the subject that keeps coming-8 up that is of most interest is feedwater, so let me talk about 9
that one first.
10 The logic for tripping feed pumps is, has been two 11 out of three on existing plants for quite a while.
The ABWR 12 difference is that the two out of three is going to be part of I) 13 our overall voting logic for control gate systems.
14 CHAIRMAN MICHELSON:
Which means what?
15 MR. SAWYER:
What that means is that at two out of 16 three, the two out of three have to agree there is a high 17 level, and if they agree, you trip.
18 CHAIRMAN MICHELSON:
All three channels may be off 19 the same power supply?
l 20 MR. SAWYER:
No.
That's the big difference in ABWR.
l 21 They all have, they all have their own separate power 22 supplies.
l 23 CHAIRMAN MICHELSON:
You have got an enhanced system
()
24 beyond normal control?
25 MR. SAWYER:
Yes.
That applies, that comment l
HERITAGE REPORTING CORPORATION -- (202)628-4888
385
/}.
1~
applies not just to feedwater control, it applies to pressure 2
control and recirc control also, but in this, but this case, 3.
we are addressing the feedwater control aspectiof that.
4 CHAIRMAN MICHELSON:
Would you tell us a little bit 5
of the detail on the two out of these three channels which do 6
the decision-making as to how they are powered and failure of-7 any one cannot affect the others and no common mode effects 8
and so forth if that's the case?
9 MR. SAWYER:
That is all the case.
I hope that in 10 the presentation that you had received on Chapter 7 would go 11 over, yesterday would have gone into that in some detail, but 12 let me try.
13 The, the power supplies are not safety grade, but 14 they are essential power, and independent power.
No single 15 failure can cause the power supply to go down.
No single 16 failure causes more than a single channel to go down.
That is 17 to say, the voting logic itself is also triplicated, so that 18 it really requires basically--and if one channel is removed 1
19 from service, for example, for surveillance, or for some other 20 reason, then the logic immediately defaults to two out of two, 21 okay, during that period of time, so basically it takes 22 multiple failures to cause the trip logic to not occur.
23 CHAIRMAN MICHELSON:
Since it is control grade, what
()
24 precautions, if any, do you take as far as physical separation 25 against floods, fires, other kinds of hazards?
HERITAGE REPORTING CORPORATION -- (202)628-4888
l 386 l
(}
1 MR. SAWYER:
I don't know the exact, I don't know 2
how to respond to that exactly.
I would have to get back to l
~3 you as to how the control systems are.
I remember, I'm sure 4
there is some separation.
I don't know that it has the same 5
high degree of separation in the barriers that the ECCS stuff 6
does.
7 CHAIRMAN MICHELSON:
What you have described here is 8
almost a pseudo safety system.
9 MR. SAWYER:
Certainly.
It is an enhanced control 10 system, recognizing that the feedwater system itself is not a 11 safety system.
12 CHAIRMAN MICHELSON:
Now the problem you still can
(
13 get into even with such enhancements is that you pay have put 14 all the wiring in one cable tray and a fire in that tray might 15 cause the feedwater valves.to go wide open and you lose 16
' control of the feedwater into the reactor as the initiating 17 event.
18 MR. SAWYER:
I don't believe that's the case.
19 CHAIRMAN MICHELSON:
It would be nitrogen--
20 MR. SAWYER:
We can confirm that, but as I said, I 21 don't know that we have gone so far as to have the, the 22 coupletely separated systems that you do when you talk about 23 your AC divisions, but I know some attention has been paid to
()
24 the common mode failure aspects that you are talking about 25 such as fire.
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1 CHAIRMAN MICHELSON:
But you have gone to separate
'2 power supplies and hopefully separate cables?
'3 -
MR. SAWYER:
Right.
4 CHAIRMAN MICHELSON: ' Hopefully.
5 MR. SAWYER:
Let's see.
One other thing I want to mention about.the feedwater system--oh, yes.
In fact,-let me 7-mention this about all of these.
8 The facts are that, that since the high level trips 9
have been implemented on BWRs, there hasn't been a' single case 10 where the high level trip failed to, failed to, failed to 11 cperate on demand.
12 There have been a couple of cases where during, f%'()
13 where particularly with the feedwater system, during the 14 course of the transient, the, the reactor vessel undergoes 35 some amount of depressurization which permit, permits the 16 condensate boost pump to pump through.
17 CHAIRMAN MICHELSON:
I think that one of the things 18 you would want to clarify also is I believe there is a manual 19 override wherein the operator takes over if two out of three 20 goes away.
21 MR. SAWYER:
The operator always has the capability 22 to override.
L 23-CHAIRMAN MICHELSON:
There was one case already I
()
24' think fairly recently in which a small amount of feedwater 25 overfill potentially occurred.
I.
I 388 b'~T '
'l MR. SAWYER:
There have been--I took a look,
{
2,
. CHAIRMAN MICHELSON:
Once you have got a manual 3
' switch which can do all of this, I will just put the fire in F
4:
the manual switch circuit somewhere and it will override and 5'
'the thing will go valve wide open and you still could, so you have got to look at the whole spectrum to see just what are 7
-the circumstances and how credible are they for feedwater
.8-overfill, seeing,-keeping in mind it was a control grade 9
design,.so there are some commonalities of all three logic 10 trains which wouldn't be allowed necessarily in the safety 11 grade design.
12 MR. SAWYER:
That's true.
( ),
13' CHAIRMAN MICHELSON:
That's the parts that worry me, 14-but_ clearly I am not saying this plant is a problem; just 15 trying to find out why you believe it isn't.
16 MR. WARD:
Are you saying because it is control 17 grade, there are some commonalities or there might be?
18 MR. SAWYER:
I think the comments you are hearing, 19 you are worried there might be, and you have asked us a good 20 question, which is to come back to you and tell you just how
.21 independent our control circuits are from each other, and 22 that's a good question.
I 23 CHAIRMAN MICHELSON:
I would like to think there are
()
24 three manual switches, one on each channel, not just one 25 manual _ switch that takes over three channels, but I don't HERITAGE REPORTING CORPORATION -- (202)628-4888
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i i.
389 (V~'t 1
know.
2 MR. SAWYER:
Well, I have to say that when you start 1
3 postulating operator errors of co-mission, you can always--
4 CHAIRMAN MICHELSON:
I'm saying fire.
5 MR. SAWYER:
But in terms of the event you were I
6 referring to that happened at a plant, last couple of years, 7
one of them anyway wasn't because of a fire, j
l l
8 CHAIRMAN MICHELSON:
That's right.
l 9
MR. SAWYER:
It was because of operator override.
l 10 CHAIRMAN MICHELSON:
When there is one circuit that I
11 can do this, then you look at what could happen to the other l
12 circuit.
l
()
13 MR. SAWYER:
Yes.
Okay.
Let me, before I finish on 14 the feedwater, let me point out that we have done, we have 15 done something about this potential for pump-through of lower 16 stage feed pumps, and as you are aware, the feed system in the j
17 ABWR is a variable speed motor-driven feed system, doesn't l
18 have control va; ve, but it does have discharge valves on the 19 pumps which can be closed, and in fact we intend to trip not 20 only the feed pumps but also the discharge valves so that when 21 the feed pumps go down, you don't, you don't have the 22 potential for any more problem until that isolation is clear.
23 CHAIRMAN MICHELSON:
Those are just normally full
()
24 open valves?
25 MR. SAWYER:
Valves are normally full open.
HERITAGE REPORTING CORPORATION -- (202)628-4888
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(}
1 CHAIRMAN MICHELSON:
We had a little question 2
yesterday.again about your adjustment, and I heard two 3
stories.
One is that two out of three of the trains were as 4
you described.
The third train had a control valve in it I 5
thought, but I must have misunderstood then.
6 You have no control valves on the feedwater?
7 MR. SAWYER:
No c'atrol valves on the feedwater 8
lines, variable speed motor' pumps.
Some of the confusion may 9
have arisen over a discussion over what is in Kashiwazaki 6 10 and 7 as opposed to what is going to be in the U.S. version.
11 CHAIRMAN MICHELSON:
No.
On your start-up then, 12 even the very lowest frequency on your power supply will give
(
13 you appropriate speed for your start-up flows?
14 MR. SAWYER:
That's my understanding.
15 CHAIRMAN MICHELSON:
So there is no full control 16 valve needed?
17 MR, SAWYER:
Right.
It turns out there is more than 18 one opportunity to isolate.
There is more than one 19 opportunity to isolate the feed system.
One is discharge of 20 the pumps and also containment isolation valves which could be 21 closed also, but our recommendation is to close it at the 22 discharge of the punps.
23 CHAIRMAN MICHELSON:
You are using one check plus l
l
()
24 one gate for containment isolation?
25 MR. SAWYER:
We are using three checks plus one HERITAGE REPORTING CORPORATION -- (202)628-4888 3
l 391 1
gate.
2 CHAIRMAN MICHELSON:
Three checks?
3 MR. SAWYER:
The reason for the large number of l
4 checks has to do with the tie-in of the reactor water cleanup l
l l
5 system and the other systems to prevent backlog.
l l
6 CHAIRMAN MICHELSON:
One of those three you are 7
calling containment isolation, and that's the one that is also 8
air-operated for testing?
9 MR. SAWYER:
That is correct.
10 MR. WYLIE:
There was something. mentioned yesterday 11 about the start-up pump.
Is there start-up pump, or 12 you--three or two full-sized or half-sized, 50 percent-sized
()
13 feed pumps?
14 MR. SAWYER:
I don't think we have any start-up pump 15 in the U.S.
version.
16 CHAIRMAN MICHELSON:
You have the control valve on 17 that start-up pump, 18 MR. WYLIE:
That is what was confusing me I guess.
19 MR. SAWYER:
I'll look--I apologize for not having 20 been here yesterday to engage in this discussion.
If there is 21 confusion on this, then I think what we ought to do is I will 22 have to review what it is that you were shown, and if it is in 23 error, we will correct the record,
()
24 MR. WYLIE:
We weren't really shown anything.
It r
25 was just a question.
HERITAGE REPORTING CORPORATION -- (202)628-4888
392
[}
1 MR. WARD:
Maybe you could just get us some--
2 MR. SAWYER:
I think what we need to show you is I 3
think, except for those who'are familiar with the feed system 4
photographs, those who know something about the ABWR in 5
general, even in our staff, there is sometimes a confusion 6
about what is the lineup for the Kashiwazaki 6 and 7 site as 7
opposed to what standard that EPRI and the utilities and GE l
8 have' agreed to for U.S.
applications.
9 MR. WARD:
You were starting to tell us that.
Can 10 you summarize what the difference is?
11 MR. SAWYER:
They have got turbine-driven high stage 12 pumps on 6 and 7 and a lower flow rate motor-driven backup.
]
()
13 MR. WARD:
Does that use the start-up pump then?
14 MR. SAWYER:
Yes.
I 15 MR. WARD:
Maybe that's what the confusion was.
16 HR. SAWYER:
Now in the U.S.,
what we have decided 17 to do is go with, with full capability pumps only, and 18 variable speed.
19 MR. WYLIE:
How many?
20 MR. SAWYER:
You've got me there.
I think it is 21 two.
l 22 MR. WYLIE:
Two full sized?
l l
23 MR. SAWYER:
Two full sized, yes.
()
24 MR. WYLIE:
These would be up about 30,000 25 horsepower?
l
393
/~'s 1
MR. SAWYER:
Yes.
V i
2 MR. WARD:
A piece?
3
.MR.
SAWYER:
Yes.
They are large pumps.
4 MR. WYLIE:
That is about what the feed pumps go 5
down.
If they are full sized, they would be 30,000.
6 CHAIRMAN MICHELSON:
Fifteen million gallons an hour 7
more or less.
8 MR. SAWYER:
Oh, they are big pumps.
Going on, the 9
HPCF and RCIC which are part of the ECCS network, but the--you 10 will recall that the way which we have the logic set up for 11 transients is that if the water level decreases to below the 12 SCRAM set point to a level which we traditionally identify as 13 Level 2, the RCIC comes on, and it will remain on until the 14 level reaches Level 8, and trip, and then, and then trip, and 15 if the RCIC is not capable or doesn't start turning the water 16 level around before the next level down which we identify as 17 Level 1 and a half on ABWR, is that both the HPCFs will come 18 on, and also they also maintain the water level between Level 19 2 and Level 8.
20 The way in which the logic is set up is, that is 21 that it is two out of four.
The whole ECCS is basically two 22 out of four, safety grade, order restart on lower level.
In 1
23 the case of the RCIC, there is additional protection for the 1
()
24 RCIC turbine in that not only is the discharge valve on the 25 RCIC pump closed at Level 8, but the steam admission valve is HERITAGE REPORTING CORPORATION -- (202)628-4888
394
/^)
1 also closed.
\\-
2 MR. WARD:
Okay, so for the high pressure core 3
flooder, the valve doesn't close.
It is just a motor trip?
4 MR. SAWYER:
No.
Never trip the motor.
We keep the 5
motor running so it goes into minimum flow bypass and close 6
the injection valve.
7 The rationale for that is that we don't want to 8
subject the system to basically a complete restart challenge 9
if you get to a low level subsequently, so the only thing that 10 has to happen if you get the low level subsequently is to f
11 reopen the valve.
12 MR. WARD:
Okay, so that's just trip, the trip
(
13 action is the valve closes?
14 MR. SAWYER:
Trip action is the valve closes.
15 MR. WARD:
Is it a single valve?
16 MR. SAWYER:
That is a single valve, because the 17 ECCS configuration typically is an outboard motor operated 18 injection valve and inboard check valve for containment 19 isolation.
20 CHAIRMAN MICHELSON:
The RCIC, of course, trips and 21 restarts.
22 MR. SAWYER:
Yes.
So does HPCF.
I 23 CHAIRMAN MICHELSON:
And the problem that you have
()
24 and concern in the past has been you can--once you get the 25 trip and you restart, you don't want to keep tripping that l
l HERITAGE REPORTING CORPORATION -- (202)628-4888
E.
395
{}-
1 RCIC so you, you go into manual mode, and you control it 2
manually, and of course in manual mode, the two out of four 3
logic disappears as I understand it in in the old plants.
It 4
does not automatically trip on the high level if you are 5
operating RCIC in the manual mode, but correct me if I'm 6
wrong.
7 MR. SAWYER:
I think that is incorrect on ABWR, that 8
the Level 8 trip, the Level 8 trip still has priority.
9 CHAIRMAN MICHELSON:
Cannot override the two out of 10 four on high level?
11 MR. SAWYER:
That's right.
Let me write myself a 12 note to confirm that.
(
13 CHAIRMAN MICHELSON:
Verify that because that would 14 be, of course take care of the, some of the difficulty we have 15 had.
16 You might check also HPCF, just make sure that it 17 does not have a manual override on it.
That would make it, of 18 course, much less credible to deliver overfill from those 19 particular source, and while you are doing it, see if you can 20 override high level.
There is a feedwater trip on high level 21 also I believe and make sure that cannot be manually 22 overridden, or can it be?
23 MR. SAWYER:
I'll check that also on the manual.
l
()
24 CHAIRMAN MICHELSON:
Those have been--the closest l
25 the boilers have ever come to this problem has been because l
HERITAGE REPORTING CORPORATION -- (202)628-4888 w _ ______-_ - _ _ _.
396 i{ )
1 people, I think has been because people are going to a manual 2
mode.
3 MR. SAWYER: -Well, the two cases that I'm aware 4
where there has been significant consequences of the overfill 5
have been on the, were the case like ARBA where, where that 6
was, it was in fact those events which-led to the installation 7
of a high level trip in the first place.
8 MR. WARD:
ARBA, was that Everton?
9 MR. SAWYER:
That's the project that has been 10 basically decommissioned.
11 MR. WARD:
I was going to ask--
l 12 MR. SAWYER:
Those events haven't been at full
()
13 pressure.
The instances that I am aware have all been this 1
14 intermediate pressure case where you have got pump-through and 15 that's what we want, to make sure we close the exit on that 16 one.
l 17 CHAIRMAN MICHELSON:
I always thought we had a high 18 level automatic trip of all the feedwater if you ever got to 19 high level, but it turned out in those cases you didn't, and 20 that's why I started asking the question to make sure what we 21 do have.
l 22 MR. SAWYER:
I will confirm what the situation is on I
23 manual.
My memory is that, that the manual control of a
()
24 system doesn't lose the trip, but my suspicion is if I check 25 into the details, if you send an instrument tech out there and HERITAGE REPORTING CORPORATION -- (202)628-4888
397 r-1 instruct him to disable the trip, that can always--that's
(
2 different.
3 CilAIRMAN MICHELSON:
This is just within the control 4
room we are asking.
Is there any way of ordinarily manually 5
overriding?
6 MR. WARD:
You are saying the experience at Everton 7
was there was not a high level trip?
8 MR. SAWYER:
At that plant, there was no high level g
9 trip because on those early plants, they were actually put in 10 service before there was an ECCS rule, and part of the backfit 11 grandfathering of those early plants was some allowance for 12 feedwater as part of the ECCS network, and as part of those
()
13 negotiations, there was a, basically a stipulation made that 14 at least in the first, first go-around, to not have a high 15 level trip because you wanted to have high, you know, higher 16 reliability of the ECCS injection function, but after that 17 event occurred, a decision was made to go the other way.
It 18 was better to avoid overfill because it was a more likely 19 event, without the high level trip.
20 For that to occur, Everton needs a system because of 21 a LOCA.
22 The only other thing to talk about that's a 23 potential big ticket item in terms of damage if an overfill 24 occurred, of course, in the main turbine itself is when the
(}
25 main turbine tripped off the same trip logic that trips the HERITAGE REPORTING CORPORATION -- (202)628-4888
398-rm-1 feedwater so if you have a.high level trip, the main turbine
'\\ b 2
stop valves and control valves will all be closed, too, to 3
protect the turbine system.
4 CHAIRMAN MICHELSON:
You will check that for manual 5
override as well?
6 MR. SAWYER:
On the turbine, yes, I'll check that 7
also, but I doubt that there is any manual override on the i
8 turbine.
9 CHAIRMAN MICHELSON:
I doubt it, but I don't know.
10 MR. WARD:
Now the relief valves, I mean the ADS I 11 guess you call it, has the capacity to relieve the supply.
12 from, from the RCIC or what?
()
13 MR. SAWYER:
The RCIC has its own branch off the 14 steam line that's, that's, that comes from inside containment 15 isolation valves directly to RCIC.
Now the SRVs are also, 16 also on those steam lines.
17 MR. WARD:
Yes.
Well, I am wondering--maybe it 18 doesn't matter, but I'm wondering about the relative capacity 19 of all the SRVs and the supply capacities of these.
20 MR. SAWYER:
Oh; the sum of all the E-is at the 21 design pressure of the reactor, that 1250 pounds which is a 22 little bit above operating pressure.
The relief capacity is 23 over a hundred percent, so all the valves handle all the steam 1
1 24 being generated.
[}
25 The RCIC in its operation requires very little steam HERITAGE REPOATING CORPORATION -- (202)628-4888
399' 1
to run.
I mean it continues to run, you know, it continues to
{}
2 run with the reactor in decay heat mode hours later, so it 3
doesn't take much steam to run a RCIC.
4 MR. WARD:
Right.
All right.
5 CHAIRMAN MICHELSON:
Did I understand you correctly, 6
there will be a hundred, full power steam bypass to the i
7 suppression chamber?
8 MR. SAWYER:
Yes.
9 CHAIRMAN MICHELSON:
I didn't realize it was quite 10 that high.
11 MR. SAWYER:
That question keeps coming up from time 12 to time in here, and the issue, there is some confusion about
()
13 the, about the percentage of the bypass system, which is 14 turbine bypass, which is the 33 percent number versus the 15 percentage of overpressure capability when isolated, which is 16 a hundred percent.
17 CHAIRMAN MICHELSON:
I think that in an earlier 18 plant, that was not the case.
It was around two thirds.
19 MR. SAWYER:
That was not always the case.
When we 20 evolved to the BWR Ss, 6s, the number got to be more like a 21 hundred percent capacity.
22 CHAIRMAN MICHELSON:
Okay.
Any--you really 23 appreciate, of course, the concern on overfill is if in the
()
24 unlikely event you got an overfill, what would be the 25 consequences?
I l
HERITAGE REPORTING CORPORATION -- (202)628-4888 L-__--____-_-
400 1
I guess you are arguing that you have adequate 2
provisions so you don't analyze the consequences?
3 MR. SAWYER:
We certainly don't analyze the 4
consequences in the context of design basis analysis.
5 In the PRA world, the worst that can happen to you 6
from one of these events is you create a steam break LOCA 7
basically.
That's the down, that's the down side.
8 CHAIRMAN MICHELSON:
I'm not sure PRAs have thought 9
through that one carefully enough then because I think it's 10 more likely that the main steam line will be the steam line 11 to, in the case of the older projects, the HPCI.
In your 12 case, the biggest steam line would be the RCIC, outside of
()
13 containment, and not in a steam case.
14 MR. SAWYER:
Except I told you that on the ABWR, we 15 do isolate the steam line.
16 CHAIRMAN MICHELSON:
Yes, and as I say, if you ever 17 overfill, don't open the RCIC steam line again because you 18 could very well bust the pipe at turbine, and that would, that 19 was the concern, because the release now is in an area outside 20 of containment which is not designed for releases.
You are 21 designing to close the isolation valve in a very short period 22 of time to terminate this.
23 It is not clear the isolation valves will even work
(}
24 under blowdown of the water slugs and et cetera, since they 25 have never seen such service in any kind of testing, so you HERITAGE REPORTING CORPORATION -- (202)628-4888
401 rg 1
just have to preclude this as any remote possibility, and you
\\s) 2 do that by extremely good designs of the safety logics.
3-MR. SAWYER:
Right.
4 CHAIRMAN MICHELSON:
And that's what you are--
5 MR. SAWYER:
The+"s our approach.
6 CHAIRMAN MICHELSON:
I think it is not an 7
unreasonable one necessarily, but we need to, we need to make 8
sure that it is not an easy manual override of it.
9 MR. SAWYER:
Okay, and that's what I will check for 10 you.
11 CHAIRMAN MICHELSON:
Thank you.
12 MR. SAWYER:
What is your pleasure?
Do you want to
()
13 go on to the next topic?
14 CHAIRMAN MICHELSON:
How much time do you want?
l 15 MR. SAWYER:
We thought we could cover this in ten 16 minutes.
It took half an hour for this one.
17 CHAIRMAN MICHELSON:
You have got a ten-minute--
18 let's do it.
1 19 MR. QUIRK:
I think that's optimistic.
I 20 CHAIRMAN MICHELSON:
Let's take a lunch break now.
]
21 We will reconvene at one o' clock.
22 (whereupon, at Noon, the meeting was recessed, to 23 reconvene at 1:00 p.m.
the same day.)
()
24 25 l
HERITAGE REPORTING CORPORATION -- (202)628-4888
402
(~\\
1 AETERNOON SEES 1ON 1:15 p.m.
I G.
2 CHAIRMAN MICHELSON:
We will come back to order now, 3
and I believe GE is going to pick up the last item from the 4
systems first.
5 We use your old auxiliary handout I assume?
6 MR. MILLER:
Yes.
I was going to say it is the last 7
three pages of the handout for Chapter 9.
I will give you a
'8 moment to find that.
9 CHAIRMAN MICHELSON:
Chapter 9, bottom of the pile!
10 MR. MILLER:
It is the foundation of the plant, the 11 auxiliary system.
12 CHAIRMAN MICHELSON:
Oh, yes.
Okay.
You are on the
()
13 relief valve?
14 MR. MILLER:
Right.
My name is Gail Miller.
I 15 would like to refresh your memory concerning the subject.
16 At the previous meeting, our Mr. James was talking 17 about testing and performance of steam relief valves, and was l
l 18 asked a question which essentially said do you test the valves 1
19 to determine also the effects of direct conduction of heat l
20 through the valve body to the sensitive parts in addition to l
21 testing the valve to determine the effects of the hot l
32 atmosphere that may be around the valve?
That was the 23 question that was asked.
({)
24 I have discussed this with the, our valve man, and 25 have received the following information.
}
HERITAGE REPORTING CORPORATION -- (202)628-4888 l
y 403 1
CHAIRMAN MICHELSON:
Who is your valve man now?
{}
2 MR. MILLER:
His name is Gary Moore.
His office is 3
across the hall from mine in San Jose.
4 CHAIRMAN MICHELSON:
Is he your MRV man?
i 5
MR. MILLER:
He is involved in that area, yes.
And 6
we would like to make the following points in that regard.
7 All of the models have been environmentally quali..sd.
This 8
means we actually test the valve.
We put the valve on a-pipe, 9
pass steam through the pipe, and let it up to the valve, and 10 we have thermal couples on the valve so that we can measure 1
11 the temperatures, especially in the sensitive parts of the i
12 valve.
(
13 I'll put up next the diagrams that we showed you'
]
14 last time concerning the two main types of SRVs, and just give i
l 15 you a general idea for the results that we have obtained from 16 these tests.
)
17 For the direct acting SRVs, we find that the heat l
18 conduction through the metal in the valve is a very minor 1
19 consideration.
We can measure it, but it is minor.
20 MR. WYLIE:
You do that in a lab?
21 MR. MILLER:
Shop I would call it rather than a lab, 22 yes.
23 MR. WYLIE:
You have a large steam source discharge l
l
()
24 and--
1 25 MR. MILLER:
That is correct.
J HERITAGE REPORTING CORPORATION -- (202)628-4888
404
./]
1 MR. WYLIE:
Fill up the room?
- (_/
2 MR. MILLER:
That is correct.
3 MR. WARD:
Fill up the room?
4 MR. MILLER:
There is an enclosure around the valve, 5
so that we can heat the air in the enclosure, and we can pass 6
steam through the pipe, so we are, we are simulating very 7
closely actual in-plant conditions.
8 CHAIRMAN MICHELSON:
What conditions do you normally 9
put for ambient around the valve?
10 MR. MILLER:
I can't give you the numbers on that, 11 but Mr. Moore assured me that we are duplicating in-plant 12 conditions--like I say, have a pipe, and a valve is on the
()
13 pipe.
We are running steam through the pipe.
We have gotten 14 closure around the vent.
We are heating the air inside the 15 enclosure.
16 CHAIRMAN MICHELSON:
Do you have an environmental 17 chamber of some sort?
18 MR. MILLER:
That is correct.
1 19 CHAIRMAN MICHELSON:
It is being pressurized with
)
20 the steam?
21 MR. MILLER:
That is correct.
As I say, with the 22 direct acting SRVs, we have found a rather minor heat l
23 conduction through the metal.
With the pilot-operated SRVs, 24 we have found a greater amount of conduction.
We have found
{}
25 some--
HERITAGE REPORTING CORPORATION -- (202)628-4888
405
('T 1
CHAIRMAN MICHELSON:
Do you insulate these valves
]
%/
\\
2 the way they are typically insulated or-proposed'to be l
3 insulated in in situ?
l 4
MR. MILLER:
That is correct.
5 CHAIRMAN MICHELSON:
Is this an air insulation?
6 MR. MILLER:
I'm not pe 4 ware of the type of 7
insulation.
8 CHAIRMAN MICHELSON:
I recall ABWR is using air 9
insulation on main steam line.
10 MR. MILLER:
Craig, do you have an answer to that 11 question?
12 MR. SAWYER:
Sorry.
I don't know the answer, O
's_/
13 either.
14 CHAIRMAN MICHELSON:
That was my recollection, but 15 it is subject to being flawed.
16 MR. MILLER:
Of course in using the information, we 17 look at differences in heat conduction, and that was added to 18 the environmental temperatures, and then using the established 19 technology, which is used to evaluate the aging of various 20 components, we calculated the, accelerated from the data the 21 aging time.
22 MR. WYLIE:
What did you conclude about the aging 23 time?
()
24 MR. MILLER:
Pardon?
25 MR. WYLIE:
What did you conclude about the aging HERITAGE REPORTING CORPORATION -- (202)628-4888
___--______--_-__---_--_--_-_-_______--_-_-______----_-----_--_-_-_a
406
'l characteristics of the valves?
2 MR. MILLER:
That they were satisfactory.
3 MR. WYLIE:
I know, but was that five years, ten 4
years, 30 years, 40 years?
5 CHAIRMAN MICHELSON:
Sixty?
6 MR. MILLER:
I don't know the answer to that 7
question.
If that is important to you, we could get that.
8 MR. WYLIE:
Yes, I think it is.
What your design 9
basis is I assume is 40 years I guess.
10 MR. MILLER:
We l '., if it were less than 40 years, we 11 would just simply have to perfctm maintenance on the valves.
12 MR. WYLIE:
It would be interesting to know what
'( )
13 your design basis is.
l 14 MR. WARD:
For the valves, or the whole plant?
1 15 MR. WYLIE:
For the valves; for the plant, it is 60 16 years, isn't it?
17 CHAIRMAN MICHELSON:
It introduces a more 18 fundamental question, of course, and that is we recognize that 19 not all components will necessarily last 60 years.
In those 20 cases, though, where you know they won't, what, what 21 provisions do we anticipate being able to see that determines 22 at what point in time you must replace this or that particular 23 part of the component or whatever?
(')
24 Is that level of detail ever prescribed as a part of
\\/
\\
25 the design certification since the 60 years is prescribed as a HERITAGE REPORTING CORPORATION -- (202)628-4888
407
[~}
'l part of the design certification?
U 2
MR. SCALETTI:
We agreed that we'would review 60 1
3 years as General Electric requested, and provide a 4
justification for 60 years of a component, and right now, I'm 5
not sure where we stand.
I don't know how many requests or 6
what parts of the plant other than the general statement we 7
would like this-to be for 60 years, and clearly the staff will 8
go into that in more detail on that if we do approve the 60 9
years.
10 CHAIRMAN MICHELSON:
Let's assume we only do 40 11 years even, which I think is the present-day situation.
12 MR. SCALETTI:
That is correct.
13 CHAIRMAN MICHELSON:
I'm not sure the staff 14 presently says that if you have a component whose life is not 16 40 years, but less, and does require certain periodic 16 replacement, I don't think you ever see those details, do you?
17 Or do you ask for them?
18 In other words, does the vender have to, the 19 designer have to justify any case where he must do something 20 to assure 40 years life?
i 21 MR. SCALETTI:
Clearly they have to justify 40 years 22 of certain components, and with a staff license--so when the 23 staff extends licenses, for, for a matter of just a few years,
()
24 in the old days we used to license for 40 years from the 25 issuance of a construction permit.
Sometimes that cut, you 1
HERITAGE REPORTING CORPORATION -- (202)628-4888 i
-408
/'T 1
know, five, ten years off an operating license, b
I 2
Now we are issuing operating license for a period of J
3 40 years from the date of, from the date of issuance of 4
operating license, so the older reactors, to justify the 5
extension of three, even two, three, four, five, ten years, 6
then we had the evaluation of certain components to determine 7
they, could--they would survive.
8 CHAIRMAN MICHELSON:
Let me ask the question f
l 9
differently.
Clearly in the case of this SRV that we are 10 talking about, and he will show on the next slide an outline 11 of it, clearly it involves certain O rings on the pneumatic 12 operator, which I doubt seriously have 60 years of life or
()
13 even 40 years of life.
Maybe five years or whatever, but to 14 what extent now when we talk about 60 year life on that valve 15 do we, to what extent do we discuss what must be replaced at 16 certain intervals to assure 60 years of life?
Do we get into 17 that?
18 MR. SCALETTI:
I don't know if we are talking 60 19 year life.
20 CHAIRMAN MICHELSON:
Assume 40 year.
21 MR. SCALETTI:
Even I don't know if it is i
i 22 necessarily 40 years where maintenance could take care of it.
j 23 We are going to, to get into maintenance programs, and with
()
24 the ABWR, it is going to be part of the design certification 25 process, so clearly it could be dealt with at that time.
HERITAGE REPORTING CORPORATION -- (202)628-4888
409
'A 1
-CHAIRMAN MICHELSON:
I don't think there~is anything
- s. -
J l
2 that.can't be made to last 60 years if you keep replacing a 3
hundred percent replacement of all parts.
4 MR. SCALETTI:
For one thing, the Japanese license 5
for one year at a time from our understanding.-
They do it one 6
year at a time except they have to come to some conclusion and 7
have some assurance certain components are going to last for a 8
certain lifetime, but I believe their actual licenses are 9
issued for one year at a time.
10 MR. WYLIE:
Is that the intent, that General i
i 11 Electric would develop a maintenance program list of
)
12 components that have to be maintained with some acceptance
()
13 criteria for continued operation of those components?
14 MR. MILLER:
That is correct.
We do develop 15 expected useful lifetimes for all components, and SRVs are 16 routinely removed from their position, taken out into the 17 shops, and given maintenance.
It's part of the--it takes a 18 good bit of equipment just to make it possible to remove one
{
)
19 of these valves and expediously move it into the shops, do the i
20 maintenance on it, and get it back into the plant, get it 21 installed without being on the critical paths, so we do, do go 22 to a great deal of effort.
I don't have at hand the number of l:
23 operating years that SRVs operate between, between
'; 4 maintenance, but it is figured into the design.
[" }
25 CHAIRMAN MICHELSON:
Now does that prescribe what HERITAGE REPORTING CORPORATION -- (202)628-4888 4
410 1
maintenance must be done.when they are removed to assure that
_(J 2
-lifetime?
3 MR, SAWYER:
Yes.
4 CHAIRMAN MICHELSON:
That's the sort of thing I 5
wondered about.
Will that kind of document be written for 6
every device which requires maintenance?
7 MR. QUIRK:
I was going to say--
8 CHAIRMAN MICHELSON:
To assure lifetime?
9 MR. QUIRK:
There are components that are 10 irreplaceable such as the vessel, the shroud, the grid plates, 11 and those are designed for the design lifetime, and there is 12 fatigue cycle analyses that are done that show over the plant
)
13 lifetime that these serve their function, as such are i
14 irreplaceable and warranted for say 60 years.
15 Then there are other components that are 16 replaceable, maintainable, and all major equipment in the 1
17 plant design has associated with it a plan of maintenance, a 18 maintenance plan for refurbishment, regeneration, and 19 reinstallment, and along with that goes any tools that are 20 necessary to facilitate this repair as well as rooms and 21 adjacent facilities to make this happen crisply and routinely.
22 CHAIRMAN MICHELSON:
Now-that's a part of the ABWR 1
23 package?
()
24 MR. QUIRK:
That is a part of the package.
25 CHAIRMAN MICHELSON:
At what point would that be HERITAGE REPORTING CORPORATION -- (202)628-4888
411 1
developed?'
r^)
(J' 2
MR. QUIRK:
In a lot of cases it has been developed.
3 We can tell you, for example, the number of that FMCRDs per 4
outage, number of recirc pumps per outage, the number of 5
6 CHAIRMAN MICHELSON:
Will this be developed prior to 7
certification?
8 MR. QUIRK:
This han been developed in many of the 9
components.
10 CHAIRMAN MICHELSON:
So those documents in essence 11 then provide the justification, provide the program which must.
12 be followed in order to meet target of whatever the design
()
13.
life in the SAR is, and I assume most cases probably 60 years, 14 but it doesn't have to be?
15 MR. QUIRK:
In most cases, probably is.
16 CHAIRMAN MICHELSON:
Those documents I guess, are 17 they looked at at all by the staff?
What do you think?
How 18 will you look at those?
19 MR. SCALETTI:
We have looked at and are aware of 20 the replacement of the internal recire pumps, I guess two 21 total replacement for, within ten years of all ten pumps I 22 guess.
We were aware of that.
We will look at it.
We will 23 look at all the maintenance documentation that General 24 Electric has developed.
(}
25 CHAIRMAN MICHELSON:
Let me ask it a little HER.ITAGE REPORTING CORPORATION -- (202)628-4888
412
{}
1 differently then, hopefully.get the same answer, 1
2 The problem that I foresee is that there are certain
- 3 programs that GE intended, were described in their maintenance 4
document, became a part of the package that was developed, 5
so-called ABWR design, were not necessarily, though, covered 6
by the certification process except maybe by inference.
7 Now you have gone into operation, you build a plant, 8
you start operating.
Our inspector comes back and says the GE 9
thing says you must do thus and so every three years and you 10 are not doing it.
The utility says no, I don't have to follow 11 that.
That's not a part of our commitment.
That's not a part 12 of the certification even.
I don't find that document
)
13 referenced anywhere in the certification.
14 And how, how do we assure that these good intentions 15 are, are enforced later by people who may not want to do quite 16 what GE had in mind to assure the life?
17 MR. SCALETTI:
Well, the intent is to develop a 18 documentation that assures that this design is built and 19 operated in accordance with the, the approved General Electric 20 design, approved ABWR design, the staff approved design.
l 21 Again, I don't know to what level the documentation l
22 will be referenced in there.
I assume that if, if it was part
'23 of the design process, that certain things had to happen, and (f
24 the staff has reviewed and approved and certified this design l
25 based on those things happening.
Then if the utility is 1
HERITAGE REPORTING CORPORATION -- (202)628-4888
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l t
1 operating this facility and is not doing that, then that is 2
outside the design certification and it shouldn't happen, and 3
I fully expect that it won't happen.
l 4
CHAIRMAN MICHELSON:
Even though you may not have 5
reviewed the documents per se, later on you feel that they are 6
enforceable?
l 7
MR. SCALETTI:
Well, to a degree; now clearly the l
8 fuels document, we review independently that reference.
We C
review the QA documentation independently, and it is 10 referenced in total in the ABWR SSAR.
11 There are other documents, and I don't know what 12 level they are located at, that may really be of no
()
13 consequence or they may be supporting information to the 14 design which just because the staff has reviewed and approved 15 that section or that SAR chapter, has not written it off in 16 the SAR, does not mean it has a generic approval from the 17 staff.
18 Now if this, GE references a document in the ABWR 19 SSAR which gives procedures or a way of doing things, and it 20 is just referenced, and the staff does not achieve that 21 document, that reference and review it, then we are clearly at 22 fault.
We should have ione that.
23 If this, if it is there and it is a document, a
{}
24 reference that, that the way it is used is specified and the 25 staff needs to use that document for its review to come to a HERITAGE REPORTING CORPORATION -- (202)628-4888
414 l
{
1 conclusion relating to the safety of the design, that document 2
is clearly approved for-the use of ABWR.
3 Now I am not saying that happens in all documents 4
because some of them may be of no consequence, and it, clearly l
5 it doesn't constitute a generic approval from the staff just 6
because it is referenced it. a SSAR Chapter that we have 7
approved.
8 CHAIRMAN MICHELSON:
Well, let's get back to the 9
specific case of, of a justification for the required 10 maintenance program to assure reaching design life, whatever 11 the design life was.
12 There is apparently a document generated by GE which
()
13 develops such a program which presumably has to be followed if 14 you are going to achieve the design life, and I don't think it 15 is necessarily even referenced anywhere in the SSAR.
16 Correct me if I'm wrong, but I hadn't seen 17 references to one yet, but maybe th?y are in there, but 18 assuming they are not referenced in the SSAR, they were not a 19 subject of a, of a staff review, they exist, the staff was 20 aware they existed, but that was as far as they go, now what 21 stature in terms of future commitment'does that kind of 22 document have?
And specifically what stature does the 23 maintenance documents have?
-( )
24 MR. SCALETTI:
The SRH, that is, the maintenance 25 documentation by General Electric will get staff scrutiny, so HERITAGE REPORTING CORPORATION -- (202)628-4888
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415 1
1 it is documented, and the intentions of the staff are to 2
-document in SECY 89-13--I believe it is the first Commission l
3 paper that went out, which laid out what we expected from the 4
standpoint of maintenance, reliability assurance, et cetera.
5 If you look at that, and I know Dr. Murley is concerned and 6
feels that maintenance is extremely importe.at, en we will 7
expect to get some sort of program from General Electric in 8
support of that maintenance program.
9 CHAIRMAN MICHELSON:
So you think we will get some 10 description later or commitment later on how we assure the 11 design life through maintenance?
12 MR. SCALETTI:
Yes.
I believe we will.
()
13 CHAIRMAN MICHELSON:
Will that b6 in a chapter then, 14 or how would I expect to see it?
It will be discussed in your 15 SSAR?
16 MR. SCALETTI:
Let GE address that.
17 MR. QUIRK:
Let me say the certification program 18 consists of basically two parts as we explained in our review 19 basis document.
20 The first part is that which is submitted in the 21 SSAR, and there goes staff research and questions and SER, and 22 that's listed.
There is about eight or ten examples of what 23 constitutes that information.
{}
There is a second part which is information that's 24 25 in the design files back in San Jose that's not submitted as HERITAGE REPORTING CORPORATION -- (202)628-4888
I
-416:
i 1
part of the SAR.but backs"up that design and as such is 2
auditable'by the staff, and:the staff then can come in on-a 3
case-by-case basis, audit.the design records, take a slice' 4
vertically through the design, go all.the way down to;the 5
bottom, and in some cases examine the purchase specs'and the 6
. maintenance-plans and everything else that they see, and 7
that's kind of the process we have described.
8 CHAIRMAN MICHELSON:
Where does the maintenance fall 9
in that process?
10 MR. QUIRK:
In the second category.
11 CHAIRMAN MICHELSON:
Only when you do the vertical 12.
slice and you ask the questions you find out.
O 13 MR. ouIRx:
Richt.
14 CHAIRMAN MICHELSON:
I would think, though, that-15 somewhere there ought to be a statement in an SSAR or 16 elsewhere that simply says that we are designing this plant 17 for whatever, this component for whatever number of years, and 18 that in order to achieve that design life, it will be 19 necessary to perform periodic maintenance and replacement of 20 portions of it, and that that is described in a, in a
=21 maintenance document which is a part of this full submittal.
22 I don't mean to say the maintenance document.
I 23 just know that that's the way you are going to do it.
If I 24 ever had any question I could fool with the maintenance
(}_
25 document, from the time the plant is built the inspector has a HERITAGE-REPORTING CORPORATION -- (202)628-4888
Il' l
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question, he can pull the maintenance document, but he has got f3
,V 2
a basis for saying this is what was agreed to in order to say 3
we got 60 years of life for this component.
It doesn't seem 4
like it is a very difficult thing to say in a very short 5
paragraph in the form of a commitment.
l 6
MR. QUIRK:
We don't have any trouble with saying i
l 7
that.
l l
8 CHAIRMAN MICHELSON:
That's, then that's all I would 9
want to know about it.
I don't want to get into detail, but I 10 would like to know the programmatic way in which periodic 11 maintenance that must be done to assure plant, to assure 12 component life is indeed done by the utility.
That buys one
()
13 of the plants.
We have only got one shot at this whole thing.
14 That's the shot we are dealing with right now.
15 MR. QUIRK:
I am struggling trying to figure out the 16 systematic recipe I guess for this, but it certainly involves 17 tech specs and it certainly involves the EQ program 18 commitments.
19 CHAIRMAN MICHELSON:
It may be in the tech specs.
20 That's something I understand--they are going to try to do in 21 the future.
22 MR. WYLIE:
Your procurement specs on at least 23 safety-related equipment would contain a section on equipment 24 qualification, would it not?
25 MR. QUIRK:
Yes.
HERITAGE REPORTING CORPORATION -- (202)628-4888
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MR. WYLIE:
And part of that would be the design 2
life that you are trying to achieve of that component, and it 3
only becomes reality after you have done the EQ testing, and 4
at that time, you just, you decide whether or not you have 5
really got the design life you thought you were going to 6
have--to have another one where you can base your maintenance 7
program on that--
8 MR. QUIRK:
Yes.
9 MR. WYLIE:
Procurement specification.
10 MR. QUIRK:
I agree with that, and we have committed 11 in part of our program to ensure that the licensing 12 commitments in the certification program are acceptably
()
13 translated into the specification.
14 CHAIRMAN MICHELSON:
You are not writing the 15 procurement spec per se.
You are writing the basic documents 16 and information down that leads to anybody being able to write l
17 the procurement spec.
At least that's what I thought.
I have 18 got to see this thing written down somewhere.
19 MR. QUIRK:
Separately for major equipment; we have 20 a maintenance plan for each specific--
i 21 MR. WYLIE:
I understood you are providing, you are 22 writing procurement specs.
l 23 MR. QUIRK:
Yes, sir, we are.
24 CHAIRMAN MICHELSON:
They may be, but that's not a
}
25 part.
That's what--
j HERITAGE REPORTING CORPORATION -- (202)628-4888
419 1
MR. WYLIE:
Wait a minute.
You are committed to the g-V 2
EPRI program, right?
3 MR. QUIRK:
Yes, sir.
4 MR. WYLIE:
It requires procurement specs?
5 MR. QUIRK:
And we have procurement specs.
It is in 6
the second category of information that I described earlier, 7
which is available for staff audit on an inspection.
8 CHAIRMAN MICHELSON:
But the Commission has not said 9
that you have to go that far.
Remember that's the 10 standardization.
11 MR. QUIRK:
That's not true.
12 MR. WYLIE:
The Commission said that they didn't
()
13 request that they be submitted for staff review for certain 14 occasions, but they would be on file for audit.
15 MR. SCALETTI:
Correct, to be available.
16 MR. WYLIE:
Well, at certification.
17 MR. SCALETTI:
There is a statement under, on--you 18 have the Commission paper.
If you will look--which is a 19 commitment in the LRB.
This doesn't deal with the procurement 20 specifications, but it--as far as maintenance goes, and it 21 states that GE has always agreed to provide an ABWR standard 22 safety analysis report to reliability and maintenance criteria 23 that a future applicant must satisfy to ensure that the safety 24 of the as-built facility will continue to be accurately 25 described by the certified design.
HERITAGE REPORTING CORPORATION -- (202)628-4888
420 1
MR. MICHELSON:
That will take care of it 2
completely.
3 MR. SCALETTI:
We have agreed to that, and that that 4
is in the LRB.
5 CHAIRMAN MICHELSON:
We will be able to read some 6
good words some day that meet that requirement?
7 MR. SCALETTI:
I certainly hope so.
8 MR. WYLIE:
I would assume then that the, the safety 9
relief valves, there is a procurement spec in the section on 10 what equipment qualifications that has been prepared?
11 MR. MILLER:
Yes, there is a rather lengthy 12 procurement specification.
/~)
(_/
13 MR. WYLIE:
We can look at that.
14 CHAIRMAN MICHELSON:
GE is lucky in that regard l
l 15 because they are building one of these.
The venders are not.
16 MR. WYLIE:
And that would cover all the replaceable 17 items I would imagine in there like the pilot relays and l
18 whatever?
1 19 MR. MILLER:
Anything called a replaceable item 20 would be defined.
21 (Slide) 22 MR. MILLER:
This is the cross-sectional diagram 23 that we showed to you last time of the direct acting SRV, and
()
24 I understand that your concern is things in this part of the 25 valve whereas the steam is over in this part of the valve, and HERITAGE REPORTING CORPORATION -- (202)628-4888 l-
421 1
our test results showed that the amount of heat conduction
(~.v}
2 through this metal part and through this metal part and maybe 3
radiation across there was rather minor, but it was, it was 4
measured.
5 (Slide) 6 MR. MILLER:
And the other type of valve that was 7
shown to you, the pilot-operated SRVs, again the concern would 8
be things over in this area of the valve, and there is a lot 9
more metal to conduct the heat than otherwise would be 10 expected if we saw more heat conduction through the metal in 11 this type of a valve, but it was acceptable.
12 CHAIRMAN MICHELSON:
Which type are you proposing?
()
~ 13 Which type are you proposing for ABWR7 14 MR. MILLER:
That I don't know.
15 CHAIRMAN MICHELSON:
You are mean you are still 16 considering both?
Is that what you are saying?
17 MR. WARD:
Are there some of both?
18 CHAIRMAN MICHELSON:
The last time we talked about 19 these, only the first type was, I thought the first type was 20 the one you were actually specifying.
This pilot-operated I
21 is--
l 22 MR. SAWYER:
That's for your information.
23 CHAIRMAN MICHELSON:
Okay.
I thought I understood.
{}
24 MR. SAWYER:
That is correct.
25 CHAIRMAN MICHELSON:
Okay.
HERITAGE REPORTING CORPORATION -- (202)628-4888
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422
{
1 1
MR. WARD:
Well, the first one, the direct acting, s-2 you know, the heat transport over, the transfer over there 3
from the main valve body might be restrictive, this thing is 4
in a tight enclosure.
The whole thing is in a tight 5
enclosure, so--
6 MR. MILLER:
Correct.
7 MR. SAWYER:
not in operation; upper drywell is 8
pretty open.
9 MR. WARD:
Okay.
It is.
Okay.
So this pneumatic 10 piston arrangement over there would be cooled by circulation 11 in the drywell?
12 MR. SAWYER:
Right.
()
13 CHAIRMAN MICHELSON:
Depending how they have 14 arranged the insulation.
People don't like to lose too much 15 heat.
They tend to overinsulate, and that's when you get in 16 trouble, and so I assume that GE will actually describe the 17 insulation?
18 MR. SAWYER:
It will be tested the way it will be 19 used.
20 MR. MILLER:
Now I will proceed and talk about 21 Chapter 14.
22 (Slide) 23 MR. MILLER:
Chapter 14 describes the initial test 24 operations.
I'll wait until things are passed out.
25 (There was a brief pause in the proceedings.)
HERITAGE REPORTING CORPORATION -- (202)628-4888
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1 CHAIRMAN MICHELSON:
Go ahead.
2 MR. MILLER:
Okay.
Chapter 14 describes the initial 3
test operation.
Part of the responsibility of constructing 4
and operating a nuclear power plant is that you prepare an 5
initial test operations, you perform initial test operations l
6 to certify that the plant is, does meet design, and will 7
operate safely.
8 The specific regulations are spelled out in 9
Regulation Guide 1,68 by the NRC, and GE has committed to 10 performing initial test operations to meet both the spirit and 11 the intent of Regulation Guide 1.68, 12 (Slide)
()
13 MR. MILLER:
Chapter 14 lists the commitments that 14 GE makes to meet the requirements of Reg Guide 1.68.
Reg 15 Guide 1.68 divides the testing program in four parts.
First 16 part are the construction tests for each of the systems and 17 structures in the plant, and to some extent, integrated 18 systems within the plant.
19 Generally speaking, all of the construction tests 20 have to be completed before you move on to the next phase.
21 Pre-operational tests are those cests which are performed to 22 certify that the plant has been constructed properly, has been 23 tested, and that the components are ready to move on to the
()
24 next phase, which is the loading of fuel, so the i
25 pre-operational test procedures would handle such things as
]
HERITAGE REPORTING CORPORATION -- (202)628-4888 I
424
(-
f3 1
making sure that all final details have been taken care of, NJ 2
all instrument set points have been adjusted, all interlocks 3
have been tested, and especially that all safety interlocks 4
and things of that sort have been met, and that the plant is 5
ready to move on to the next stage, and during the 6
pre-operational tests, it is the, it is required that you have-7 all systems in operation, in service ready to go to meet all 8
of your tech spec requirements, and at the end of-the 9
pre-operational test, you have completed all of the 10 obligations that you made during the construction permit.
11 Then move on into start-up tests, which involve, 12 which involves the loading of fuel and up through initial
()
13 criticality, power operation, ascension up through into 14-preparation for commercial operation.
These are the general 15 test phases for the plant.
16 (Slide) 17 MR. MILLER:
GE has committed that these test 18 operations would be performed under the guidance of what is 19 called a start-up coordinating group.
This is a group that 20 meets at the plant site and is composed of representatives of l
21 the plant owners, GE, the architect-engineer,. constructor, and i
22 other people who are involved such as manufacturers and 23 providers of equipment or services.
24 The main function of the start-up coordinating group
{
25 is to be the final approval of the procedures for the I
HERITAGE REPORTING CORPORATION -- (202)628-4888
425 1
individual test and to certify that the test schedule is 2
proper, which means that the system that is about to be tested 3
is in such situation that it can be safely at the time tested, 4
and that it fits into the overall condition of the plant.
5 Obviously the most dif ficult thing about testing a f
6 plant is that you cannot have all of the other systems tested 7
and operating properly before you test the system that is 1
8 occupying your attention, so it takes a great deal of effort 9
to make sure that enough systems are in operation to safely 10 test each system.
11 (Slide) 12 MR. MILLER:
GE is committed, we will have at each
()
13 site a resident manager who is the one voice of GE.
He has 14 the following responsibility of review and approving all test 15 procedures.
The function of reviewing can be partially 16 delegated, but the responsibility cannot.
17 He provides technical direction to the plant staff 18 as required, manages all GE site personnel, takes care of 19 liaison with San Jose, is a member of that start-up 20 coordinating group, and he has responsibility for all the GE 21 supplied equipment.
He has the responsibility for being the 22 spokesperson so that when GE speaks on site, it speaks with 23 one voice.
l
(}
24 MR. WARD:
Is that essentially what has been done at l
25 past GE plants?
l
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426' i
)
1 MR. MILLER:
That is correct.
l[
2 MR. WARD:
So that really isn't anything new?
3 MR. MILLERi It is nothing new.
We are not 4
. proposing anything radically new in this' area.
5 (Slide) 6 MR. MILLER:
We are also'committedfto have at each 7
site a start-up administrative manual to supplement and work 8
alongside plant. operating procedures.
9 The purpose of this manual is not to supplant or 10 replace the plant operating procedures.
It is merely to cover 11 those subjects which are not appropriate in permanent plant 12 operating procedures, so we cover this kind of thing in'the.
()
13 activities of the start-up group which would not necessarily 14 be in the plant operating procedures, because the start-up 15 group will finish their function before commercial operation.
16 We define the way we are going to prepare test procedures so 17 that they are all prepared in a uniform manner, how we are 18 going to review the test results, how we are going to 19 establish the requirements et cetera, et cetera.
20 This is so that it is all, all of the tests are done 21~
'following the same guidelines.
22 (Slide) 23 MR. MILLER:
We specify in Chapter 14 how we are 24 committed to handling test results.
Of course, the purpose of 25 this is to provide not only the successful tests are HERITAGE REPORTING CORPORATION -- (202)628-4888
427 1
adequately reviewed, but the unsuccessful tests are given 2
proper attention, and of course, these steps take place in 3
order.
Start-up engineers obtain the results.
Those results 4
are reviewed by the start-up engineers.
Then GE and who else 5
is involved review the results.
All these comments have to be 6
reviewed.
Start-up supervising personnel have to review and 7
approve the thing.
And of course, the-final responsibility 8
for review and approval belong to the plant management staff,
~
9 so there are many steps involved.
10 (Slide) 11 MR. MILLER:
Again, pre-operational tests, the start 12 of pre-operational testing is when the construction tests have
()
13 been certified as having been completed and the main method, 14 the main commitment during pre-operational testing is that the 15 standby, the start-up coordinating group will review and 16 approve all testing before it occurs.
17 (Slide) 18 MR. MILLER; Then in the start-up test phase, of 19 course the main function of the, of this phase and the other 20 phase is to make sure that the Reg Guide 1.68 requirements l
21 are, are followed.
22 This involves pre-fuel load checks and provides all 23 of the tests to make it possible to implement the plant
(}
24 technical specification.
1
?
l 25 The initial fuel loading is a test procedure.
The l
HERITAGE REPORTING CORPORATION -- (202)628-4888
428 r
1 fuel is loaded according to pre-approved procedures and
(
2 pre-approved data are obtained during each step of the fuel 3
loading.
4 Initial criticality is also a start-up test phase, 5
and we move into the more detailed low power testing, power 6
engine testing,'and the warranty demonstration, which would 7
lead to the successful completion of the test operations.
8 Are there any questions?
9 CHAIRMAN MICHELSON:
This is really, as you 10 say--anything new here?
This is pretty much what you have 11
.been doing on current plants?
12 MR. MILLER:
That is cor ect.
()
13 CHAIRMAN MICHELSON:
Questions?
I see none.
I 14 think that takes care of that item.
15 MR. MILLER:
Thank you.
16 CHAIRMAN MICHELSON:
It appears that we have no 17 other items except the closed item on control rod drive, is 18 that correct?
Do you need your meter break now?
19 MR. SCALETTI:
No.
I took care of that.
20 CHAIRMAN MICHELSON:
We will need to clear the room 21 because I think the next subject is proprietary.
I will have 22 an open meeting for the Subcommittee afterward, yes, and this 23 meeting, this discussion is supposed to take about 30 minutes.
{' }
24 (Whereupon, at 1:50 p.m.,
the Open Session was 25 recessed, and the meeting was convened in Closed Session.)
HERITAGE REPORTING CORPORATION -- (202)628-4888
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455 i
f~3 1
CHAIRMAN MICHELSON:
So we can reopen the meeting V.
2 for the Subcommittee discussion.
i 3
Do the--I don't believe we need to record the 4
Subcommittee discussion.
It is going to take just a few 5
minutes, so I believe we can terminate the record now if you 6
will, and we will have our Subcommittee discuusion.
7 (Whereupon, at 2:40 p.m.,
the recorded portion of 8
the meeting was adjourned.)
9 10 11 12 0
13 14 15 16 17 18 19 20 21 22 23 24 25 HERITAGE REPORTING CORPORATION -- (202)628-4888
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CERTIFICATE p.
O 2
L 3
This-is to certify that the attached proceedings before the 4
United States Nuclear Regulatory Commission in the matter of:
5 Name:
Advisory Coamittee on Reactor Safeguards--Subcommittee on 6
Advanced Boiling Water Reactors (Open Session) 7 Docket Number:
8 Place: Bethesda, Maryland 9
.Date:
May 11, 1989 10 were held as herein appears, and that this is the original 11 transcript thereof for the file of the United States Nuclear 12 Regulatory Commission taken stenographically by me and, 13 thereafter reduced to typewriting by me or under the direction i
14 of the court reporting company, and that the transcript is a 15 true and accurate record of the foregoing proceedings.
16
/S/ $ 0 N w n w
17 (Signature typed): Catherine S. Boyd 18 Official Reporter 19 Heritage Reporting Corporation 20 21 22 23 24 1
25 O
Heritage Reporting Corporation (202) 628-4888
_.