ML20041F564
| ML20041F564 | |
| Person / Time | |
|---|---|
| Issue date: | 03/09/1982 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| Shared Package | |
| ML20041F565 | List: |
| References | |
| REF-10CFR9.7, TASK-A-49, TASK-OR SECY-82-097, SECY-82-97, NUDOCS 8203170159 | |
| Download: ML20041F564 (72) | |
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UNITED STATES OF ANERICA 2
NUCLEAR REGULATORY CONNISSION m
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PUBLIC NEETING j
5 8
BRIEFING ON STATUS OF l
7 PRESSURIZED THERNAL SHOCK ISSUE 8
l 9
Room 1130 l
to 1717 H Street, N.W.
11 Washington, D.C.
12 Tuesday, March 9, 1982 l
13 The Commission convened, pursuant to notice, 14 at 10:00 a.m.,
NUNZIO PALLADINO, Chairman, presiding.
15 PRESENTS i
16 NUNZIO PALLADINO, Chairman 17 JOHN AHEARNE, Commissioner 18 PETER BRADFORD, Commissioner i
19 YICTOR GILIN. SKY, Commissioner
[
l 20 THOMAS ROBERTS, Commissioner 21 STAFF NAKING PRESENTATIONS AT THE NEETING4 22 SHELDON TRUBATCH, Office of General Counsel 23 SAM CHILK, Secretary 24 FORREST RENICK, Commission Staff 25 STEVEN HANAUER, NRR ALDERSoN REPORTING COMPANY. INC.
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2-3
~~
NAHOLD DENTON, NRH 1
2 BAY WOODS, NHR 3 ALSO PRESENT:
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4 MR. RANDALL 5
MR. KLECKER 6
MR. VAGINS 7
i MR. THROM 8
9 10 11 12 13 14 15 18 17 18 19 20 21 22 l
23 24 25 l
l 1
ALDERSON REPORTING COMPANY,INC,
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l DISCLAIMER This is arr unofficial transcript of a meeting of the United States Nuclear Regulatory Cennission held on March 9, 1982 in the Cccurission's offices at 1717 H Street, N. W., wasnington, D. C.
The
- netting was open to public a.ttendance and observation.
This transcript
- has not been reviewed, corrected, or edited,. and it may contain inaccuracies.
The transcript is intended. solely for general infomational purcosas.
As provided by 10 CFR 9.103, it is not part of the forinal or infomal record of decision of the matters discussed.
Expressions of opinion in
.this. transcript do not necessarily reflect final deteminations or
~ beliefs.
No pleading or other paper may be filed with 'he Comission in any proceeding as the result of or addressed to any statement or argument A
conta.ined herein, except as the-Conmission may auth'orize.
I
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4 i
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PR0CEEDINGS 2
(10:00 a.a.)
i
)
3 CHAIRHAN PALLADINO:
Good morning, ladies and, 4 gen tlemen.
This morning the Commission meets to receive t
5 a briefing from the staff on the status of their effort i
6 to resolve the pressurized thermal shock issue.
/
i; 7
On August 21, 1981, the Director of the' Office
[
8 of Nuclear Reactor Regulation sent letters to eight 9 selected licensees requesting information on tF.e 10 pressurized thermal chock issue.
Eight licensees and L
11 two owners groups I understand have responded to the 12 request for information.
The staff has these submittals 13 under review.
I understand that they have not completed
~
14 their review.
They are here this morning to provide us 15 an interia report on the information they have obtained 16 so far.
17 I should also point out that this afternoon we 18 have a briefing on the same subject by representatives-
[
19 of AIF and EPRI, and we may get additional insight into 20 the status of this issue.
21 Unless other Commissioners have opening 22 remarks, I would propose turning the meeting over to Mr.
23 Denton to proceed with the presentation.
i 24 HR. DENTON Thank you, Mr. Chairman.
25 The dimensions of this problem have not i
I ALDERSoN REPORTING COMPANY,INC, I
5 1
changed significantly since our last briefing, but we do 2
have better knowledge of some of the details as a result
.1 3 of the submittals we receive from utilities and the
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i 4. owners groups.-
5-The presentation vill be made by Steve
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6 Hanauer.
We also have with us today Roy Woods, who is s
7 the project manager for this unresolved safety issue.
8 Steve?
i 9
HR. HANAUIRa' Thanks.
10 This status report will try and tell you what 11 ve have learned, which is quite a lot, and give you also 12 some feeling for what we still think is ahead.
In very 13 brief summary, things seem to be okay for design basis 14 kinds of' events.
Where we still have work to do -- and 15 I have been told in the last hour that work is under way i
16 in the, industry on a scale we had not known about before 17
-- is working in the land of multiple events and l
18 operations -- operator actions and the like -- which we 19 learned at Three Nile. Island and elsewhere is an area 20 not well encompassed by our stereotyped d4 sign basis, so 21 that although it was quite reasonable and proper, the 22 ansvers that we've gotten and the work that we have sc 23 f ar f rom the industry is largely focused on design 24 basis.
25 Help is at hand and more work is being done in ALDER $oN REPORTING COMPANY. INC,
6
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1 this other area.
I 2
(At 10:05 a.m.,
Commissioner Gilinsky entered 3 the room.)
4 MR. HANAUER:
The first vugraoh is just the i
5 title.
You have handed out to you a stack of vugraphs, 6 plus in the back some handout material, which is what i
7 rou got from us a couple of days ago.
r 8
(Slide.)
e The second vugraph, please.
10 This shows how we intend to attack the 11 problem.
We ove you this summer, the summer of
'82, our 12 initial position, which will be based on whatever we 13 know, which is quite a lot.
We intend to give you at 14 that time an updated evaluation of the safety of
'S con tinued operation of the plants and whatever initial i
corrective actions we beli+ Tee tre required or are te 17 prudent.
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18 Now, the intarrast.;oa ve vill have at that time
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39 is largely what's in the house nov and what's intended 20 to be furnished in the next little while, which will be 21 reviewed more on a later vugraph.
Then either in the x
22 summer of --
23 COMMISSIONER AHEARNE:
Steve, is that 24 primarily the 150-day report?
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MR. HANAUER:
Yes, which is this stack I have 25 I
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in front of me.
It's NRC-generated material and it's 1
2 additional material which we have been told just in the m
3 last few days is going to come in as a result of our 4
meetings and our questions and our discussions with the 1
5 owners groups and the owners which we have been having 6
the last couple of weeks.
7 The generic resolution --
8 COMMISSIONER AHEARNEa Before you nove to I
9 that, what is the eighth plant?
10 MR. HANAUERs Three Mile Island Unit 1.
They 11 asked for some more time and got it.
They are 12 scheduled, as are all BCW plants, to get a BCW vritten 13 plant-specific report, which they then have to review 14 and send to us.
The BCW owners have chosen to write a 15 series of plant-specific results rather than a generic 16 one.
17 CHAIRMAN PALLADIN0s Did THI-1 ask for more 18 time for the 1SO-day report?
19 MR. HA N A GER s.
Yes, sir.
20 MR. DENTON:
We granted them more time in view 21 of other difficulties that they have had.
We expect to 22 have it in hand before taking our initial position.
23 COMMISSIONER AHEARNEs Is that an open-ended 24 time for them or do they have a fixed time by which ther 25 were supposed to have it in?
ALDERSoN REPORTING COMPANY,INC,
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1 MR. DENTON:
My understanding is that BCW was 2 to provide an initial draft to the company this month.
-s 3 Then if it was adequate --
4 COMMISSIONER AHEARNE My question was, ther 5 asked for more time past the 150 days.
Were they given 6
an open-ended time?
7 NR. DENTON:
No, not open-ended.
Before 8 J un e.
We didn't pin them down to any particular time, 9 because there are a long list of B&W plants in the 10 pipeline for this review.
11 HR. HANAUER:
The generic resolution is the 12 set,of regulatory requirements for continued operation 13 throughout the plant lifetime, and it involves the 14 development of criteria which may or may not be proposed 15 by us this summer depending on what we know, for if it 16 were ever to be necessary, reactor shutdown or vessel 17 annealing.
18 Shutdown and annealing, of course, are very 19 expensive actions.
If they are needed soon, we will 20 tell you.
The owners have all said they are not 21 needed.
We believe this is surely true for the 22 short-tern, but the goal of the generic resolution is to 23 write down the required analysis and the criteria for 24 opera tion throughout plant lifetimes so we can know what 25 the requirements are.
And they will be based not only ALDER $oN REPORTING COMPANY,INC,
9
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1 on what we have in hand now, but on whatever else we 2 need, including sone NRC programs under way.
3 Finally, there's a confirmatory research 4
program that involves irradiation of large specimens, l
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5 the construction and thermal shock testing of large 6 model vessels.
That will go on for a number of years.
[
7 COHNISSIONER GILINSKY a Is that under way i
8 now?
9 HR. HANAUER:
Tes, sir.
10 COHHISSIONER GILINSKY:
Where is that being i
11 done?
12 HR. HANAUER:
Primarily Oak Ridge, as part of i
13 the heavy section steel technology program.
14 COHHISSIONER GILINSKY:
Thank you.
15 (Slide.)
16 HR. HANAUERt The next vugraph shows in i
17 somewhat more detail where we stand now and what we hope i
18 to do by this summer, the summer of
'82.
We vill of 19 course use all the information we have, and I have i
20 stacked up here in this notebook the 60-day and 150-day l
i 21 replies.
We have eight 60-day replies and, as we 22 discussed, seven 150-day replies and the generic 23 Westinghouse owners group report.
There was also a l
24 generic Combustion Engineering report which was too
)
25 heavy to carry, which deals with the smaller part of the l
1 ALDERSoN REPORTING COMPANY,INC,
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probles, small break loss of coolant accidents.
2 CONHISSIONER AHEARNE:
I gather f rom your 3 statement in the table that that itself was not a 4 generic pressurized shock report.
5 NR. HANAUER:
No, sir.
It dealt with 6
pressurized thermal shock and other aspects of small 7 break LOCA's.
It's a THI action plan item and there is f
8 some relevance to this problem.
e What we have to do this summer in particular 10 is to specify any plant-specific corrective actions, of i
11 which I give some examples in this vugraph.
In these 12 industry analyses we received from the seven plants, i
13 there is substantial reliance on operator actions, as i
14 there is for most long-time transients in our plants, 15 and we foresee a program to make those assumptions come j
16 true with regard to pressurized shock.
i 17 Those programs are in fact already under var 18 in connection with the procedures improvement program 19 and TMI Action Plan t.C.1, about which you were briefed 20 in connection with the case review some months ago.
And 21 ve expect to do some auditing and to see some attention 22 paid in these older, more embrittled plants to make sure 23 that those assumptions have a good chance of beinq 24 true.
i 25 CHAIRMAN PALLADINO:
Steve, are you going to ALDER $oN REPORTING COMPANY,INC, t
11
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1 get into these assumptions?
2 HR. HANAUERs Yes, sir, we will.
3 CONHISSIONER AHEARNEa You are going to get to
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4 these charts, then?
5 HR. HANAUER They obviously can't be 6
displayed.
I had not planned to discuss them in detail, 7
but can answer any questions about them.
8 In general, the point is that in their 9
analyses the owners have assumed that certain critical to operator actions do in fact take place at certain 11 specified times.
He have asked them two kinds of 12 questions.
One is, is this a cliff we fall over?
If 13 the assumed time is ten minutes, is eleven minutes a 14 catastrophe or is it only ten percent worse?
And there 15 are analyses under way to get us this information.
16 CHAIHHAM PALLADINO:
If you use minutes as you 17 did, it's one thing.
But if you speak in terms of 18 tripping the reactor coolant pumps in 30 seconds, that's tg an item we ought to talk about a little bit.
20 HR. HANAUER:
Yes, sir.
The tripping of the 21 reactor coolant pumps is something we instigated after j
22 Three Nile Island to protect ourselves against small 23 break LOCA's.
At Ginna and other incidents, they have 24 indeed been tripped promptly.
25 We do not think, but we have asked and we are ALDER $oN REPORTING COMPANY,INC,
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looking, that that was in fact essential to the 2
pressurized thermal shock business.
^-
3 COMMISSIONER AHEARNE:
But you do have -- for 4 example, on Maine Yankee operator action is considered 5 and there you have for the main steam line break the e
tripping in 30 seconds.
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7 MR. HANAUER:
Yes, sir, that's the assumption 8 they make.
l 9
Dr. Woods?
l 10 NR. WOODSt I believe the point is it tends to 11 make it worse, typically.
If the pumps stays on, you 12 have better circulation.
You have stagnation of the
[
13 cold safety injection water if you trip the pump.
So 14 that assumption tends to make the overcooling worse.
15 CHAIRHAN PALLADINos You mean the assumption i
16 they take that action?
17 dR. WOODS:
If it trips the pump.
18 CHAIRMAN PALLADIN0s What concerns me is if 19 he's going to take that action in 30 seconds I'm 20 concerned that 30 seconds is a rather short period of 21 time in which to try to assess what's happened, and I'm i
22 not clear that he vill know enough, the operator will 23 know enough, to do so, that he should trip or not trip.
24 ER. HANAUER:
That was the conservative 25 assumption they made and we wrote it down.
If he I
ALDERSoN REPORTING COMPANY,INC,
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doesn't trip the pumps, pressurized thermal shock is 2
better, but maybe small break 10CA is not as well 3
served.
4 CONHISSIONER AHEARNE:
Let me ask probably a 5
summary question.
And I recognize that just looking at 6
the summary charts can be quite misleading, as I was 7 aisled on that particular one.
But the conclusion I was 8
reaching on the charts was that if no credit is given 9 for either vara pre-stressing or operator action that 10 all these plants are in trouble.
11 NR. HANAUER:
That certainly has some elements 12 of my understanding also.
If you give no credit at all 13 14 (Laughter.)
15 HR. HANAUERs If you give no credit at all for 18 operation,these plants are all in trouble in a whole 17 variety of ways, and pressurized thermal shock is one of 18 them.
We have a substantial dependence on operator 19 actions in the longer.ters for many transients that can 20 get these plants into bad trouble, and this is one of 21 them.
22 COMMISSION ER AHEARNE:
What kind of time --
23 what's the shortest time that you found the operator has 24 to take an action in order not to have the plant get 25 into trouble on this?
l ALDER $oN REPORTING COMPANY,INC,
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1 HR. HANAUERt I can't answer that question l
2 direc tly.
The shortest time that was assumed for one of l
3 these actions was, I believe, ten minutes.
And we have 4 now asked them, is eleven minutes a. catastrophe or is l
5, there some longer time in which it can take it?
f e
CHAIRHAN PALLADINO:
Steve, are you saying the 7 decision that he has to make in 30 seconds is not 8 crucial?
9 MR. HANAUER4 Tha t's correct, it is not.
It's 10 something they assumed and we wrote down that kind of 11 assumption for further investigation.
12 CHAIRMAN PALLADINO Are you going to look at i
13 what happens if the individual makes a different I
14 decision?
15 HR. HANAUER:
Yes, sir.
Not all possible 16 different decisions, but the ones that seem essential.
17 NR. DENTON:
I think you hit one of the areas t
i 18 that Steve will come to as something we will focus on f
19 between now and June.
i 20 ER. HANAUER:
If you will look at page 5 --
l 21 CHAIRNAN PALLADINO Why don't you proceed, i
22 then.
23 NR. DENTON:
I want to make one point about j
f 24 tripping the pumps.
I think it does, as Roy said, 25 aggravate certain situations, and we may well find that l
ALDERSoN REPORTING COMPANY. INC,
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1 for such as Ginne when you trip the pumps and it r
2 aggravates the problem of thermal shock because you've
'N 3 got cold water coming into loops with no flow in th em.
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4 HR. HANAUER:
As usual, if you consider a
(
5 large spectrum of things that can happen, there is not 6 in some cases a completely unambiguous directive.
7 Tripping the pumps is not the best for everything that 8 can possibly happen, and this is true of some other 9 important activities also, and we do count on operator l
10 analysis and action.
11 For example, we have decided that he should 12 trip the pumps very quickly, but in some situations he 13 should turn them back on.
You will recall the 14 discussion of this in the Ginna incident.
15
( At 10:20 a.m.,
Commissioner Bradford entered 16 the roca.)
17 ER. HANAUER:
We have pretty much covered 18 number four.
If you will glance at number four for just 19 a minute, you will notice that we have things going at 20 several laboratories in order to augment the staff 21 a ctivities.
22 (Slide.)
23 (Slide.)
24 Number five summarizes the industry submittals 25 received so far.
They show, using their assumptions and ALDER $oN REPORTING COMPANY,INC, i
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their analyses, which may in fact turn out to be 2 -entirely acceptable -- we're still reviewing them 3
that with one minor exception all the plants vill 4 survive satisfactorily to the end of their life for all 5 the accidents analyzed.
6 The one exception shows 21 more years, which 7 is a lot, and therefore we don't feel the exception is 8 very important.
9 CHAIRMAN PALLADIN0s That's based on these 10 various assumptions?
11 HR. HANAUEB4 Yes, sir.
I l
12 In the Westinghouse generic report, which uses i
l 13 rather more conservative assumptions than the 14 Westinghouse plant-specific owners report, they show I
15 some plants in difficulty for the most limiting 16 transient in three or four or five years, which is of i
17 course very different from the plant-specific analyses, 1
18 which give 20 or 30 or more years.
l 19 CHAIRMAN PALLADIN0s And what's the reason for i
a) the difference?
l 21 MR. HANAUEHs The reason for the difference is 22 the assumptions, particularly on operator action, varm 23 pre-stressing and vessel properties.
The generic 1
I 24 Westinghouse report uses generic vessel properties, l
l 25 whereas the owners have gone back to the specific I
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properties as measured in their vessels and the copper 2
and nickel levels as measured in their vessels and made 3
what they believe are more realistic projections.
4 CHAIRHAN PALLADIN0s I was going to say, in C
the Westinghouse report they did take benefit of warm a
pre-stressing.
7 HR. HANAUER.
In some areas, yes.
8 CHAIRHAN PALLADINO:
I'm looking only at this 9 t able -- oh, yes, for small breaks and large LOCA's.
10 COHNISSIONER AHEARNE:
How much vara 11 pre-stressing are they counting on, what kind of 12 temperature rise?
13 HR. HANAUER:
I'll give an initial answer and 14 call on my warm pre-stressing experts.
15 (Laughter.)
to Thel have a vara pre-stressing model which 17 gives a mechanical picture of where it works and where 18 it does not work, which relates to the previous history 19 of stress and temperat.ure in the vessel.
They then 20 applied the model of what happens in the particular 21 transient, including the heat transfer at the metal, at 22 the water, and they predict a temperature stress time 23 history in the vessel, and where it fits the vara 24 pre-stress situat;on they use it.
25 Now, this means that f or that particular l
l ALDER $oN REPORTING COMPANY,INC, CG N__& lCoOm_M3&MG DM_____________________.
18 1
combination of pressure and temperature and time and for 2
that particular vara pre-stress model, what they do is 3
legitimate.
We are still reviewing the models.
Our 4
biggest problem is that that particular pressure, 5 temperature, time history is one of a large number that 6 could happen, and that depends on the assumptions and 7 that's the kind of thing we are still looking a t.
8 So the issue is not so much varm pre-stress j
9 per se, but the degree to which it is sensitive to 10 exactly what you assume in pressure and temperature, and 11 that is still being looked into.
12 COMMISSIONER AHEARNEa When you say the degree 13 to which it is sensitive, you mean the degree to which 14 it is actually beneficial?
15 HR. HANAUER:
The degree to which it is 18 actually beneficial and the degree to which some 17 apparently minor change in operator action or equipment 18 action or timing of events would change it from a vara 19 pre-stress success story to a non-vara pre-stress story, 20 and whether that really matters.
21 We have seen one calcula tion where they in 22 effect turned off the vara pre-stress by applying a 23 pressure change, a pressure increase such as was 24 actually seen in the Rancho Seco incident, and it 25 produced a somewhat deeper crack, but was not ALDERSoN REPORTING COMPANY,INC,
_ 00_VIRGlNIA AVE. 3.W., WASHINGTON, D.C. 20024_Ei) $84-2346 4
19 1
catastrophic.
2 COMMISSIONER AHEARNE What you're saying is
~'
3 that operator -- controlling operator pressurization can 4 be critical to find out how beneficial wars' I
5 pre-stressing is?
6 MR. HANAUER:
Yes, sir.
And the thing to 7
investigate is not the mechanical details of warm
~8 pre-stress, but the degree of confidence we have that i
9 the pressure and temperature vill go as predicted.
i 10 COMMISSIONER AHEARNE4 And that gets then also 11 to the operator procedures.
12 HR. HANAUER:
Yes, sir.
That turns out to be 13 a central point in pressurized thermal shock.
14 COMMISSIONER AREARNE Having all of that 15 background, could you then give me the approximate 18 amount of vara pre-stressing Westinghouse is talking 17 about?
18 HR. HANAUER:
No, sir, I can't.
But maybe Mr.
ig Randall can.
20 ER. RANDA1La In the analyses done to date, 21 vara pre-stress is a go-no go thing.
If they calculate 22 to decrease monotonically after you get in the brittle 23 range, they assume that safeguards against any factor.
t f
24 It's not a graduated delta.
25 COMMISSIONER AHEARNE How are they getting l
1 ALDERSoN REPORTING COMPANY,INC, t
20 i
t the vara pre-stressing?
2 MR. RANDALLs It occurs because the maximum 3
NK-1 occurs before *.he temperature is in the brittle 4 range.
5 COHNISSIONER AHEARNE:
And they are getting 6 that by what actual procedure?
7 HR. RANDALL:
That's simply something you 8 calculate the pressure and temperature versus time.
i 9
COMMISSIONER AREARNE:
But are they, for 10 example, heating up the water?
Is this just their 11 analysis of 12 HR. RANDALL:
It's just their analysis.
13 CONHISSIONER AHEARNE:
What does the operator 14 do in those cases in order to stay in that kind of 15 condition?
16 HR. HANDALL:
Well, mainly not repressurize.
17 I'm not the right man to answer that.
18 COHNISSIONER AHEARNE:
That 's the main thing 19 h e mu st do?
20 ER. RANDALL:
Yes.
l 21 COMMISSIONER AHEARNE:
And what is the 22 critical time that he has to make that decision ?
Is 23 this again also the ten-minute time?
i 24 MR. RANDALL Hay tells me it's ten minutes 25 for a steam line break.
I l
ALDER $oN REPORTING COMPANY,INC.
400 VIRGINIA AVE., S.W., WASHINGTON. D.C. 20024 (202) 554-2346
9 21 l
HR. KLECKER:
I'm Ray Klecker.
1 2
If you assume an instant'aneous double-ended 3
steam line break, that's.where we talk about the 4 ten-minute time f rame for operator action.
For a 5
stuck-open valve, in either the primary or the secondary 6
system, the time allowable for the operators is more 7 like 30 to 40 minutes typically.
8 CHAIRMAN PALLADINO:
But Steve, with the 9 uncertainties that we seem to have at the present time, 10 are there clear procedures for the operators at these 11 respective plants, and are they procedures reasonably 12 consistent so far as our analyses are concerned?
13
- 58. HANAUER We've been looking into this and 14 I don 't have a real answer.
Let me tell you what we so 15 far have found out.
We have explored this problem, 18 particularly with the Westinghouse owners, because we 17 vere ready and they had the right people in at a recent 18 meeting, so I know most about them.
19 Their procedures improvement program since 20 Three Nile Island has resulted in improved guidelines 21 which include some pressurized thermal shock considerations, and we are going to audit these in the t
23 seven or eight plants that we have chosen for our first 24 look and see.
25 Some plants have in fact submitted their ALDEREioN REPORTING COMPANY,INC, a m ana m aawwnw=m
22 1
procedures to us.
They have a variety of approaches, 2
none of which is the symptom-oriented kind of thing we j
3 expect to see in the next year or two as a result of our 4 longer-range procedure improvement.
5 What we are going to look at and what we have l
6 not yet managed to do so is what the plant-specific 7 procedures actually provide and what the operator 8 training programs actually do in these plants.
And in g fact, at least one plant has already told us they are 10 implemen ting and have already implemented some 11 retraining of operators in this area.
So we are going 12 to get, but do not have today, an opinion and evaluation 13 of how things are in the plants in this respect.
14 CHAIRMAN PALLADINO:
Are you satisfied that 15 the individual utilities are looking at the procedures?
16 MR. HANAUER:
He have asked then to.
The 17 seven replies we have all say that they have done it or j
18 are doing it.
i 19 CONNISSIONER GILINSKY4 Could you give an 20 example of just what it is an operator would be expected 21 to do under these circumstances?
What is it that we're l
r 22 talking about?
l 23 HR. HANAUER:
The principal activities are 24 turning on or turning off or throttling the aux feed or i
25 the main feed, which determines the cooling through the 4
l ALDERSoN REPcRTING COMPANY,INC, CIS%CDR$ Q Ek% NAS FG3 A P2}M
i
^
23 i
1 steam generators, turning off or throttling the high 2
pressure injection for the primary, which replenishes
~
3 the fluid, but also cools the primary, and some valve 4 manipulations if he has leaks in the primary or 5 secondary system, where he wants to control the loss of 6 fluid but at the same time not provide repressurization 7 if he has had an overcooling.
8 So the principal manipulations --
,9 CHAIRNAN PALLADINO:
How about reactor coolant 10 pumps?
11 NH. HANAUER:
He has to decide whether to turn 12 them on or off.
In general, as we discussed a while age 13 14 CHAIRHAN PALLADINO:
And whether to restart.
15 HR. HANAUERS And if they're off, whether to 16 restart.
17 In general, if he turns them on he gets very i
18 good mixing and the overcooling which can still occur l
19 through the steam generators seems to be moderated and 20 extended, made less abrupt.
But that's only a very 11 superficial aaalysis and it has to be looked at.
So 12 those are the kinds of things he has to do.
23 COMMISSIONER GILINSKYs I know, but can you 24 take it a step further?
What is it you expect him to 25 do, to throttle the HPI or what?
I l
l l
ALDER $oN REPORTING COMPANY,INC.
24
~
1 HR. HANAUER I can't recite it.
There's a 2
series of things and some difficult decisions he has to 3 make.
That's why we're glad it's 10 and 30 minutes, not s
4 the 30 seconds.
5 COHHISSIONER GILINSKIa Do you see those as 6 consistent with the other requirements?
7 HR. HANAUER:
Tha t's wha t. we ' re going to 8 evaluate and have not arrived at an assessment of.
9 COHNISSIONER AHEARNE:
Tell se if this is 10 vrong.
The impression I have is that we are not yet 11 sufficiently sure. what are the right steps to take, and 12 so at the moment we would be a little.hard-pressed to 13 review a set of procedures and say, this is right or 14 here are changes you should make to make it right.
15 MR. HANAUER:
Technical guidelines about what 16 the right steps are have been developed.
They are being 17 refined in the sympton-oriented procedure development 18 that is still going on.
But a set of technical steps 19 has been developed, has been reviewed, and has been 20 accepted.
We're re-reviewing them.
That's what is l
21 90180 08-22 COMMISSIONER AHEARNE:
Accepted by --
HR. HANAUER:
NRC in connection with the 23 1
24 post-THI improvements.
25 COMMISSIONER AHEARNE:
Yes, but are you saying ALDER $oN REPORTING COMPANY. INC.
400 VIRGINIA AVE., S.W WASHtNGToN. D.C. 20024 (202) 564-2348
25 1
that NRR now is confident that they know what are the 2
right steps to take in a variety of sequences?
3 MR. DENTON:
No, we haven't completed that.
4 That's an ongoing effort to review the vendor's l
5 guidelines, which encompass all possible scenarios that 6 ve vorry about, and then make sure that those guidelines l
7 are converted into procedures.
And that's a big part of 8 our effort.
9 CHAIRHAN PALLADIN0s And I gather you have f
i 10 criteria against which to evaluate them, is that right?
11 ER. DENTONs Well, once the guidelines are 12 approved from an analytical basis, then you make sure r
13 that each utility has converted those guidelines into 14 the proper procedures.
Now, we have gone through 15 several rounds and we have audited several rounds of 18 procedures each time.
But it's an area that is still 17 being approved.
i 18 CHAIRMAN PALLADINos But I gather he said l
l 19 criteria.
I don 't know what a typical criterion might 20 be.
l 21 MR. HANAUER:
The guidelines we are talking 22 about look like procedures, but they are couched in i
i 23 general terms.
They say turn on the HPI or throttle the l
24 HPI so as to m.sintain level in the pressurizer.
Now, in 25 each plant they have to say, turn valve number A-46B2.
l ALDERSoN REPORTING COMPANY. INC.
i l
400 VmGNA AG 0,W, WN 08 8 OH) 023 En3
26 1
They have to translate this both with specific L
2 equipment, names and numbers, and also with particular i
3 numbers, at 200 gallons a minute or whatever.
j i
4 MR. DENTON I don't want to leave the 5 impression that this area is clear and clean.
It 's on 6 our list at the bottoa line to review the training 7 program for operators and look at the procedures, and l
8 that will be a big focus in our review.
g What we have learned is that while you can do 10 a perfect analytical job for any given scenario, when 11 events happen the operators don 't always know what
[
t 12 scenario they are in.
So we are trying to push toward l
13 sympton-oriented procedures so the operator will do the 14 correct thing for the class of event, and then 15 eventually get into one pattern or another.
16 COHNISSIONER AHEARNEa Let se see if I can 17 understand.
Are you saying, A, you are confident that 18 You know what are the important event sequences for each 19 class of plant; and B, you know theoretically in each of 20 those sequences what the operator ought to do?
21 HR. DENTON:
I think you will find in another 22 slide that's part of the ongoing effort.
We don 't knov 23 that today, and that's why we're taking it through June.
24 25 MR. HANAUER:
Today's situation is that the ALDER $oN REPORTING COMPANY,INC,
l l
27 l
l i
1 PWR owners and two of the owners groups -- we haven 't 2 set with the third one yet -- h av e s aid this is true.
3 A, they know what to dos B,
the procedures are in place 4
to do it.
And we have.to review that, and that's what 5
is going on.
6 Now, it was reviewed with less intensity in 7 connection.with the post-Three Mile Island, but we are 8 re-reviewing it and looking harder a t it.
s COHNISSIONER AHEARNE:
But in post-Three Mile 10 Island, as I recall, there was not anywhere near as much 11 concern at the time on this particular --
12 NR. HANAUER:
Tha t's correct.
But it is 13 mentioned at least in the guidelines.
14 COHNISSIONER GILINSKYa Do I detect a change 15 in your attitude about operator responses?
Are you more 16 cheerful than you were before about relying on operators 17 to deal these situations?
I sensed in our earlier 18 presentations that there was less of an inclination to 19 allow reliance on operators.
20 NR. HANAD3R:
Perhaps more realism has 21 obtruded, and the realization that although we have 22 automatic actions for immediately required functions, 23 that in the many minutes to hours time frame we are 24 almost entirely dependent on our operators for a large 25 number of functions, including this one.
And so far at ALDERSoN REPORTING COMPANY,INC,
28 1
least we have not decided that we ought to change this.
2 MR. DENTON4 Since I had stressed that issue 3
earlier, I think it was because originally the industry 4 view was there was no problem because the operators 5
vould always do the right thing.
And of course, if ther 6 do the right thing they can control the repressurization 7 and keep it well in hand, and we said you cannot assume 8
that ther always do the right thing.
9 But obviously, as in most transients, 10 eventually you've got to give the operators credit for 11 performing the right actions.
And the time gets -- so I 12 think there has been a recognition on our part that 13 operator action in either 10 minutes or 30 minutes or 14 one hour is essential, as it is for maintaining most 15 essential core e.apability, where the plants are not so 16 forgiving that the operators can leave their stations 17 for long durations.
18 And it's trying to make the-plant as forgiving 19 as we can from an operational standpoint, and then make 20 sure the procedures are written to enab3e them to i
21 interpret conditions and assure a high reliability to 22 perform the right actions.
23 CHAIRM AN P ALLADINO:
Harold, you have some 24 supplementary help back there.
25 MR. MURLEY:
I'd like to add a point if I ALDERSoN REPORTING COMPANY,INC, 8N ERCA N f4GL A N
29 i
1 could.
I might have been some of the source of 2
pessimism on operator action when this issue came up.
I 3
think the point to keep in mind that always bothered me 4 and many of the staff is that there are competing l
5 demands on the operator during these complex 6
t ransien ts.
7 We saw it at GLnna.
At one and the same time 8
you have a loss of coolant event where you were losing 9 coolant and you're also potentially overcooling the 10 vessel.
So he has to do the right thing.
As someone 11 says, you've got to keep the core cold and the vessel 12 hot during all this.
13 At. the same time, he doesn 't know what valves i
14 are open and what tubes might be broken and so forth.
I 15 personally have not seen anything in the last several i
16 months that would kind of change my view about the i
17 importance of the operator action.
I don't think the 18 procedures are going to be able to cover all these 19 complex multiple failure events.
20 COMMISSIONER GILINSKY:
Well, what lesson do 21 You draw from that Ginna experience? I was going to ask 22 about that.
23 MR. EURLEY It personally, I think, confirmed 24 my concern that he is going to be confused during one of
'l 25 these types of transients, and his main concern is, j
ALDER $oN REPORTING COMPANY,INC.
30 1
properly I think, to maintain the core cool.
And you 2
will have the task force report I guess in a few weeks 3 on that.
I suspect it will say that they really were 4 not concerned about the vessel at all during that event, 5 and that's a pattern we have seen in many of these 6 overcooling events.
They just had other things on their 7 minds.
8 CONNISSIONER GILINSKY:
I think I agree with 9 you, but that seems to be at odds with what Steve is 10 saying.
11 RR. HANAUERs I hope not.
It's a proper 12 concern and it's why we 're going to go out and audit and 13 see whether the industry statements that this is in hand 14 are true or not, or to what extent they are true.
15 Perfection is not going to be achieved.
16 There is a real chance -- and we have had an 17 example in 1979, where the operators are really 18 vrong-headed about something going on and choose an 19 incorrect course of action which leads to bad trouble.
20 What we intend to do in the short term is to see to it 21 that the programs, the procedures, the training, the 22 understanding of the operating crews is such as to make 23 this adequately laprobable.
24 CHAIENAN PALLADIN04 Well, it will be 25 interesting to see the extent to which the owners have ALDERSoN REPORTING COMPANY,INC, GN6 NRM
31 j
1 taken into account the concerns such as were primarily 2 oxpressed.
G HR. HANAUERa It might be well to address that 4 question this afternoon.
5 MR. DENTON:
And the key obviously is the 6 degree to which the shift has occurred, that as the 7 vessel NDT shifts to higher and higher ranges, it's more 8 crucial that operators act sooner and correctly.
If we 9
were able to maintain the toughness down to very lov 10 temperatures, then we would have a lot more 11 flexibility.
12 COH'HISSIONER AHEARNE:
You used the word 13
" sooner."
Now, it wasn't clear from the previous 14 comments that there.vas a shift -- that the ten minutes 15 was a shift in time.
I can understand why it becomes 16 more and more important that they act correctly, but 17 does the time also shift?
18 ER. DENTON :
I'll let Steve answer that.
But 19 I would think if you had really high -- if you just let 20 the temperatures go up and up, I assume you would have 21 to act f ast.
22 MR. HANAUER:
This is surely true.
The 23 analyses we have, which are for the end of life, use 24 numbers like 10 and 30 minutes for these different 25 operations.
One would presume, although I have not seen ALDER $oN REPORTING COMPANY,INC, MN666
32 1
the calculations, that there is more time for a tougher 2 vessel, and of course for vessels in their initial 3 conditions there is nothing much they can do to hurt l
4 them.
Vessels with an RT-NDT of zero degrees or lower l
t 5 are not subject to overcoooling transients in that 6 range.
j 7
MR. DENTOMs Steve, do you have any 8 expectation that af ter these analyses have been 9 completed and the extent of operator action that is to needed has been analyzed, that we can get a clear course 11 of action for the operators, or'do you think we are 12 always going to be in a state where, in view of the 13 competing nature of the phenomenon involved, tha t you' re 14 going to have trouble deciding what to do?
15 You see, I don't mind depending on operators i
16 when it's pretty clear that if this happens you do 17 this.
It's when you've got competing actions that --
i 18 CONMISSIONER GILINSKY That was.the thing I
19 that concerned me, too.
It's one thing to rely on l
operators when you can lay out a pretty clear course.for 20 j
21 them to follow, but it's another thing if they have to 22 do what is described a s 'valking on. a knife edge.
23 NR. HANAUER:
Let me answer that in some i
24 apparently disconnected parts, and let me say, this
~ _..
25 answer is made in some ignorance because we hy?t not ALDERSoN REPORTING COMPANY,INC, 400 VIRGINIA AVE., S.We WASHINGTON, D.C. 20024 @ 564-2345
33 1
done the work.
2 I think the ideal situation -- there is one 3
thing they should always do and will probably not be 4 achie ved.
There won't b~e any unambiguous, always turn 5 on the high pressure injection or always turn off the 8 high pressure injection.
There are some sequences when 7 you want it on and some when you want it off, and 8
therefore we have set up the requirement f or choice and 9 understanding of decisionmaking.
10 CHAIRMAN PALLADINOs But would the 11 characteristics under which you would do one or the 12 other -- do you think there you have a chance of being 13 clear?
You called it symptom-oriented.
14 MR. HANAUZR:
The preliminary results from 15 procedures development have not shown any blind alleys 18 where they either cannot decide, don 't know enough to 17 decide in a situation where they have to, or where there 18 is not any good decision.
If such things showed up, 19 they would be very serious negative findings on the 20 safety of the plant, and we're so grateful that so far 21 at least that has not shown up and the work is well 22 along.
23 Proper pa ths have been delineated and in at 24 least one example'they have used what they call decision 25 trees to point the operator, and these paths have in ALDERSoN REPORTING COMPANY. INC.
34 1
f act turned out out to be ways the operator can deal 2
with the various combinations of symptoms.
3 This work is incomplete, so I cannot really 4 dot the "i", cross the "t",
and wrap a ribbon around 5
it.
So I gave you a partial assurance.
6 CHAIRMAN PALLADINO:
Hell, I guess we ha ve 7 interrupted you.
8 NB. HANAUEB:
Yes.
The other interesting 9 thing on this vugraph is the bottom one, and that is the to concicsions of the owners that, since they had shown 11 satisfactory safety for the lifetime of the plant, 12 little or no corrective action is required.
In some 13 plants low neutron leakage core loading patterns have 14 been implemented, and in some plants procedure and 15 operator audits and training have been initiated.
Other te plants have simply said, no, nothing is needed.
17 CONNISSIONER AHEABNE:
Not even revised 18 procedures?
19 HR. HANAUER:
No, sir.
20 He suspect -- we think that the indications 21 are tha t we vill be requiring something in these areas 22 this suaner.
23 CONNISSIONER AHEARNE:
I gather none of the 24 plants reached the conclusion that heating up the water l
l 25 was a --
ALDER $oN REPORT 1NG CoadPANY. INC.
400 VIRGINIA AVE, S.W. WASNINGToN. D.C. 20024 (202) 564 2346
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ER. HANAUER:
No, sir.
2 CHAIRMAN PALLADINO:
Would not the options
~
3 that the operator has to consider be reduced in number 4 if they were varming the ECCS vater?
5 MR. HANAUER:
Yes, in some events they would 6
be.
In others, in the secondary induced transients, 7
that would help much.
8 CHAIBRAN PALLADINO:
For certain situations 9
10 HR. HANAUERs For certain situations it 11 would.
But it would also decrease the effect of the 12 energency core cooling.
As usual, there are tradeoffs 13 here.
14 CHAIRNAN PALLADIN0s Is it a very difficult 15 ites to achieve if one decides to achieve it?
16 NR. HANAUER:
Yes.
The ECCS vator is in a 17 very large tank which is often outside.
18 CHAIRMAN PALLADINos But it would not be 19 prohibitive?
20 MR. HANAUERs It's not prohibitive.
If 21 needed, it can be done.
22 COMMISSIONER AHEARNE:
Can I ask a question on 23 the basis of your submittal?
You have them analyzing 24 certain design basis accidents.
In your paper you sent 25 out you had them analyzing certain standard design basis l
l ALDERSoN REPORTING COMPANY,INC,
36
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1 accidents.
Did you provide them a set of standard 2 accidents?
l 3
MR. HANAUER:
No, sir.
They used what ther m
4 have.
That's the space they are used to working in and 5
that's where they started.
There are also some 6 anticipated operating occurrences which are also the the j
7 chapter 15 kind of stuff they are supposed to do.
8 COMMISSIONER GILINSKYs I understand the staff g has been in contact with sono of the European requiatory l
10 agencies or operators.
Are you familiar with what they 11 have done on this?
12 MR. HANAUER:
Only secondhand.
I know that in i
13 some foreign PER's they have taken more severe sensures 14 than any of ours to decrease the flux, and they are 15 considering at least putting in dunar fuel elements in 16 certain strategic elements, rather than the more elegant 17 but less draconian fuel element shuffling that is being 18 proposed in this country.
19 CHAIRMAN PALLADINO:
But you said some have 20 done some adjustaent of fuel elements?
Did I understand 21 you correctly?
22 MR. DENTON:
I think that's correct.
We have 23 somebody in the audience who would know foreign 24 experience.
25 CHAIRMAN PALLADINO:
I was thinking in this ALD&tSoN RfPoRTING COMPANY,INC,
-__-__- -________-__-_ ___ _ - _ ~ _ _ - - ~ ~
37 1
country.
2 HR. HANAUERt In this country, there are lov 3 neutron leakage cores actually installed or planned soon 4
for some of the PWR's.
5 CORNISSIONER GILINSKI:
Was Tom Hurley going 6
to add something?
I 7
NR. NURLEY:
I had mentioned in briefings last 8 summer, there are three plants we know of where they g have taken the fuel out of the outer row and have 10 replaced it with dummy assemblies.
11 CHAIRMAN PALLADINO:
This is foreign?
12 HR. MURLEYs Yes.
In German y, the Schtada 13 Plant and Obrenheim Plant, they are about 500 megawatt 14 PWR's, early 1970's vintage, high copper veld material, 15 and they did it just for this reason, really.
16 The other is the Lovisa plant in Finland, and 17 on that we don't know the metallurgy of that vessel too 18 vell.
Now, I might add that those are f ar more -- they 1g reduce neutron radiation far more than the things that 20 are being talked about in these fuel management schemes, 21 an order of magnitude or more.
22 COMMISSIONER AHEARNE:
Was there at least one 23 plant that also vent to hea ting up the 24 HR. MURLEY:
Yes, the Lovisa plant heated up 25 its emergency cooling water.
i ALDER $oN REPCRTING COMPANY. INC,
38 1
CONNISSIONER GILINSKY Do they have a 2 different assessment of the probles, or are they just a 3 little more cautious or what?
4 HR. MURLETs At Lovisa, it was embrittling at 5 a much, auch faster cate than even the older plants are.
8 So they had to do something, and I think that's the 7 reason.
In Germany I think they projected that at the 8 end of their life they were going to be quite brittle --
g I don't remember the RT-NDT's, but I think they were 10 well under the 350-degree range Fahrenheit -- if ther 11 had done nothing.
So they took action about five years 12 ago.
13 CHAIRHAN PALLADINO:
And those areas where 14 they put dummy fuel elements, did they have to reduce 15 the power significantly?
16 NH. MURLEY:
Yes, that 's my understanding.
17 CHAIHEAN PALLADINO:
Do you have any feel for 18 how much?
ig HR. MURLEY:
I don't, know.
go CONNISSIONER GILINSKY s Is it significantly?
l l
21 NR. HUBLETs I don't even know that.
It i
22 sticks in my mind it's about a five percent type of
(
23 reduction.
24 CONNISSIONER GILINSKY:
I would think the 25 outer ring would have an overall small effect on the ALDERSON REPORTING COMPANY,INC,
39 1
amount of power.
6 2
MR. MURLEY:
That's right.
3 (Slide.)
4 NR. HANAUER:
The next vugraph is our present 5 set of numbers on these vessels.
I have some older 6 numbers for Three Nile Island, but of course we don't 7 have their 150-day response.
For Three Mile Island the a licensee's conservative value is 1-7-0, 170, and the 9
staff's conservative value is 160.
These are the 10 numbers from the previous evaluation.
11 The two left-hand columns are comparable in 12 many ways.
They are conservative evaluations based on 13 some bounding cui:ves for embrittlement and some 14 conservative views of what is in the vessels.
In the 15 right-hand colu n we have put down some numbers which we to would not use for regulatory purposes, but we have done 17 some probabilistic studies, and in order to do them we 18 had to make a stab at what our best guess would be of 19 the actual state of those vessels, that is to say the 20 number which is about a 50-50 chance that the RDT is 21 above and below.
22 CHAIRMAN PALLADIN04 I'm not sure what those 23 numbers are again.
These are the shifts?
24 MR. HANAUERs No, these are the absolute 25 values.
l ALDEASoN REPoMTING CoWP ANY. INC.
40 1
CHAIRHAN PALLADIN0s These are the values and i
2 not the shifts?
3 NR. HANAUER Yes.
And these right-hand 4 numbers, then, are our best quess, our best estimate of 5
where these vessels stand.
And as you can see, for most 6 of the vessels they are a good deal more favorable than 7 the conserva tiv view we have and the conservative view 8 the licensees have when they are asked to choose a e number that the vessel is not likely to exceed.
10 This can also give you the evaluation that 11 these numbers are uncertain by 50 or 100 degrees, and 12 that's probably correct.
That is to say, if you really 13 vant to be sure you have a conservative number you will 14 go 50 to 100 degrees above your very best scientific 15 estimate of where that vessel night stand.
16 CHAIRMAN PALLADINO:
If you were using 50, is 17 it plus or minus 50, or is it minus nothing, plus 50?
18 MR. HANAGERs I don't understand your 19 question.
20 CHAIRHAN PALLADINO:
Well, if you say the 21 uncertainty is 50, is i t --
22 HR. HANAUER:
It's plus or minus 50 on these 23 right-hand column values.
Let me check again with Mr.
Randall.
He says res.
24 CHAIRMAN PALLADINO4 So the uncertainty is 25 ALDERSON REPORTING COMPANY,INC, i
~
41 1
actually greater.
I'm just trying to understand.
2 (Slide.)
3 MR. HANAUER:
The next vugraph, number seven, 4
gives our preliminary findings, which are of course 5
based substantially, but not entirely, on what the e
industry has told us.
7 The Rancho Seco transient will not cause 8
vessel failure in any plant today or for the next few 9
years.
There has been a lot of use of the Rancho Seco 10 transient as kind of a benchmark.
It actually happened, 11 ve know what happened, and we can apply the pressure and 12 temperature curves directly.
Even though for other 13 reactors they are not what would happen if the same 14 sequence of events were to occur, they are a convenient 15 thing to use for analysis.
16 CHAIRMAN PALLADINO:
And this is independent 17 of operator a.ction?
18 HR. HANAGER No sir, this is whatever the 19 operator did at Rancho Seco and whatever the equipment 20 did at Bancho Seco.
You use the temperature and 21 pressure that actually occurred.
l 22 COMMISSIONER BRADFORD:
And which of the l
23 RT-NDT' temperatures do you use?
24 MR. HANAUER:
The conservative one.
25 So that none of the vessels in the U.S.
tcday ALDERSoN REPORTING Co&WANY,INC, I
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42 1
would be broken by that collection of temperatures and 2
pressures which actually occurred.
3 CHAIRMAN PALLADIN04 When you say a few years, 4
you mean at least two or at least th ree ?
5 MR. HANAUER It depends on whom you ask how e
many years.
7 CHAIRMAN PALLADIN0s It 's more than one ?
8 NR. HANAUER:
It's much more than one.
9 CHAIRMAN PALLADINO:
Much more.
10 MR. HANAUER In most plants, it's the 11 lifetime of the plant, given their assumptions.
12 CHAIRMAN PALLADINO:
This says next few 13 years.
14 MR. HANAUER:
Tha t 's as f ar as we 're villing 15 to go today.
16 CHAIRMAN PALLADINO But in your mind the next 17 f*W years means at least two to three?
18 NR. HANAUER:
At least two or three, yes.
We 19 think some things are going to turn out to be prudent
)
20 this summer.
Surely something in the operations area, 21 perhaps for the more embrittled plants, something in the 22 fuel management area.
There may be others.
23 The principal results, which we have already 24 discussed at some length, is highly dependen-on what i
25 you get for an answer, on what you put in for ALDER $oN REPoATING COMPANY,INC.
43 1
assumptions.
This is, of course, just a platitude until 2
you get more specific, and the specificity is for these 3
transients the highly dependent nature of the result on 4 what the operators do and what equipment turns on and 5
turns off and is told to do.
6 Thus the difficulty in deciding this issue 7
will not in general be a difficulty in deciding about 8 metalurgy or c brittlement, but will be in deciding 9
which transients could occur and which transients we to have to do something about and, whatever the result of 11 that is, how to make it come true that transients more 12 severe than.that have an acceptably low frequency of 13 occurrence.
That is going to be the hard issue in this 14 problem.
15 HR. DENTON:
I think we have recognized these 16 issues are the key, and that's why I mentioned earlier 17 the dimensions of this problem have not changed much in 18 a year.
We've learned a lot of details and a lot of 19 fine structure, but we do intend to bring it to a 20 conclusion and give you a recommendation on our original l
21 schedule of June, and try to have rste definitive 22 answers to these uncertainties.
23 NR. HANAUER:
There is also, inte restingly l
24 enough, a question of how you define success and i
25 failure.
ALDEASoN REPORTING COMPANY. INC.
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~~
1 (Slide.)
2 If you will look at number 12, it is called 3 acceptab1'e criteria.
You will see a display of the
~.
4 various acceptance criteria which have been proposed by
[
5 the different owners groups and in some cases even by i
6 different owners within the groups.
7 Calvert Cliffs and Fort Calhoun Combastion s plants have proposed two different criteria s one for 9 anticipated operational occurrences, which are high 10 frequency events, for which ther propose no crack 11 initiation; the other for design basis accidents, which 12 are low frequency events, which require crack arrest and 13 non-through crack f ailure of the vessel.
14 And as you see, there are other combinations 15 -- a quarter of the vessel crack, three-quarters of the 16 vessel crack, one-inch deep crack -- which need sorting 17 out, and this is an open issue how we will define 18 success.
It's something that we have to do between now l
ig and this summer.
20 COMMISSIONER AHEARNEs Capital "T" means 21 thickness?
22 MR. HANAUER:
Yes, sir.
23 Noving now back to the next in progression, l
24 number 8 --
25 CONNISSIONER ROBERTS:
What do you mean by the ALDGISoM REPORTING CoIWANY,INC,
45 1
statement, "aaterial properties seen better in hand"?
2 ER. HANAUER:
The measurement of them and the I
3 orediction of then seem not to present any serious 4 difficulty in resolving the issue.
We think we know hov 5
to do it.
6 (Slide.)
7 Yugraph number 8 gives the ingredients of the 8 generic resolution.
We have to have the criteria, we 9 have to have whatever analysis is required.
We have to 10 decide on this issue of wha t is acceptable, and we have 11 to tell them what to do.
12 Now, we have to do some of that this sunser.
13 If we get enough information we'll do all of it this 14 sunner, or there may be some further work left to So.
15 Now, in the next vuoraphs I tell what the to major issues are.
But in fact we have already gone over 17 them in substantial measure.
18 Number 9 talks about the initiating events.
jg This is back to the question of what has to be assumed.
20 We have asked the plants to go back, as Oconee already 21 did in their original submittal, and rack up their LER's 22 and tell us what kind of precursors they've had.
Let's 23 use the plant information to guide us in th e perhaps 24 different propensity of the different plant designs for 25 overcooling transients.
ALOGA8oN REPoMTING CoWPANY,INC,
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We already know that Oconee found a 2 substantial number of events they called precursors.
We 3 have been told orally that at least in one other plant 4
they had a good look and they did not find any 5
precursors.
6 This information is being sent to us for the 7 other plants.
We believe that it's necessary ta put 8 some more emphasis on likely events, and as I told you 9 at the beginning of this briefing we have been told in 10 the last 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that work is under var to organize 11 what is known about these.
12 CH AIRMAN P ALLADINO:
What is known about 13 what?
14 ER. HANAUEBs About the more likely events.
15 There have been calculations about transients of various 16 kinds, particularly in this procedure upgrading program, 17 and two of the three owners groups have already told us 18 they are organizing this material to see what it tells 19 them about pressurized thermal shock, in an effort to 20 get better understanding outside of design basis 21 accident space about the kinds of transients that have 22 to be considered.
23 What have we learned?
At Three Mile and many 24 other places, the events that actually occur are 25 sequences which involve many correct and typically ALDER $oN REPCRTING COMPANY,INC,
47 1
several incorrect things that happen.
At Ginna, not 2 only did the steam generator tube break, but the 3
power-operated relief valve stuck open.
At Three Mile i
4 Island the sequences of failures and mistakes is very l
l 5 voll known.
f 6
The things that do not give us -- that do not i
7 get registered in this exclusive list are the things 8 where things did not go wrong and the plant was e recovered without any significant incident.
- However, r
10 there ir a bunch of analyses of these things and these 11 people are digging them out and organizing them and 12 looking for their significance to pressurized thermal I
13 shock.
i 14 Dr. Woods?
15 HR. WOODS:
I'd like to add, when you start 16 getting into these multiple failure or multiple event 17 sequences, the probability of any given sequence that 18 you alght be looking at is admittedly very low.
The way 19 you get into trouble is there are such a large number of 20 those possible sequences, and that's also what makes 21 them very difficult to deal with.
22 CHAIRMAN PAL 1ADIN0s You say the pa rticula r 23 events are very low?
24 MR. WOODSa Yes.
The chance of that 25 particular sequence of events happening is extremely ALOGRSoN REPORTING COMPANY,INC,
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low.
~'
2 CHAIRNAN PALLADINO:
That particular 3 sequence?
4 NR. WOODS:
That particular sequence is very 5'
low.
But there are a lot of different ways you can get l
8 to the same end point.
And just putting an event up on 7 the screen and saying this involves 18 failures and
-9 8 therefore the probability is to and we shouldn't 9 consider it, that's not strictly correct if that's to representative of such a large number of sequences, and i
11 that's the difficulty of handling this type of event.
12 But yet, that's where we believe some fair 13 fraction of pressurized thermal shock risk is, in that 14 large number of possible sequences.
15 (At 11:04 a.m.,
Commissioner Gilinsky left the 18 COON.)
i 17 CHAIRMAN PALLADINO:
I guess we vill get a 18 handle on what that large number is?
19 NR. HANAUER:
We'll get some handle on it from 20 a number of programs.
The procedure improvement 21 program, some of the probabilistic risk assessments 22 which are being done, have some insight into this area, 23 although they do not consider the kind of detail that we i
24 are talking about.
They look at a bigger picture.
But 25 they tell us the probabilities of certain classes of l
ALDERSoN REPORTING CCMPANY,INC.
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49 1
events which form bounds on the kinds of things we are 2 looking at.
3 (Slide.)
4 Vugraph number 10 is the material that we have 5 already discussed in event sequences, the role of the 6 operator, the timing of events, and the need to consider 7 a variety of event sequences.
The role of the operator, 8
which has also gotten a lot of discussion already, is 9 given in vugraph 11.
.I don't think there is anything on 10 there that we have not already discussed at some 11 considerable length.
12 CHAIRMAN PALLADINO:
Let me make sure I 13 understand the question about the 30 seconds.
That's 14 where I get worried.
If something has to be decided in 15 30 seconds, it seems like an awf ully short period of 16 time.
Are you assuring me that these analyses or tables 17 show, where an action has to be U ken in 30 seconds, 18 that those are not significant actions with regard to 19 the events you have described?
20 MR. HANAUER:
I can give you even more 21 assurance.
They are significant when the unfavorable 22 direction was taken.
23 NR. DENTON:
The 30 seconds goes back to 24 events that transpired --
l 25 CHAIRMAN PALLADINO:
I'm sorry.
For these l
l ALDERSoN REPORTING COMPANY,INC,
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particular events.
It might be right for some other 2 events?
3 HR. HANAUER:
It is right for some other s
4 events, and that's why it was assumed to take place, 5 even though unfavorable for these events.
I would like 6 to check my backup for this.
7 MR. WOODS:
That's right.
I think Ed Throm 8 from the staff.
9 MR. THROMs The 30 seconds is typically not a 10 time that the operator has to consider the event and 11 act.
It's the fact that he does get a low pressure 12 safety injection signal within that time span and 13 current procedures call for tripping of the reactor 14 coolant pumps on low pressure safety injection 15 actuation.
16 CHAIRHAN PALLADINO:
Thank you.
All right.
I 17 just wanted to be sure.
18 MR. DENTONs But pumps on and pumps off is one 19 ve got into right after THI as recommended by the 20 vendors in order to preserve coolant inventory for 21 certain classes of small breaks.
And I think the more 22 ve look at it the more we are finding a need to be 23 circumspect in how that is applied, because we continue to find circumstances in which that goes the wrong way 24 25 for certain classes of events.
AA.DERSoN REPoR?tNG COMPANY,INC,
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It night have been the correct answer for a 2 certain narrow class of consideration, but not for 3
others.
j 4
CONMISSIONER AHEARNE You're in, but you're 5
not yet out of it.
l 8
NR. DENTON:
That's right, we're not out.
7 MR. HANAUER:
We have pretty much covered 8 numbers 11 and 12.
Perhaps you will turn to number 13.
9 (Slide.)
t 10 It is called generic resolution.
This 11 represents the steps in a program which is under way at 12 Oak Ridge National lab, los Alamos and Idaho.
This is 13 an NRC program to provide audit capability and some 14 audit calculations, to give us additional insight into 15 the problem.
18 We are taking three example plants, one for 17 each vendor, and we are doing our own calculations, both 18 probabilistic and deterministic, event sequences, tg pressure and temperature, fracture mechanics, and we 20 vill use tha t to get improved insight into the 21 development of criteria, the understanding of the 22 s en sitivities.
And we are also looking into 23 independently the possible corrective actions.
24 CONHISSIONER BRADFORD:
What are your criteria 25 you 're using in the lead plants?
Are they the ones that ALDetSoN REPORTING CoWPANY,INC,
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seem to have a problem?
2 NH. HANAUEBs We have only picked the first 3 one, which is Oconee.
It is one of the seven.
It is a 4
plant we know a lot about.
It's a plant whose owner is 5 willing'or is going to be told -- and in Oconee ther 6 have been very willing and very cooperative -- to give 7 us the required information.
8 There will be a Westinghouse and a Combustion, 9 and this choice is now being made.
10 (Slide.)
11 The next vugraph shows the longer-range 12 confirmatory research program in the real of both theory 13 and experiment in the behavior of these materials.
14 COMMISSIONER BRADFORD:
Before you move away 15 from the research program underway, is that sort of the 16 phase one research?
And if so, when do you expect it to 17 be completed?
18 NR. RANAUER:
That program is now scheduled 1g for completion, that program on the previous vugraph, in 20 October 1982.
21 (Slide.)
22 So we expect along in the winter to have 23 assimilated those results and to be able to use them.
24 COMMISSIONER BRADFORDa Let's see.
If you i
l l
vill not have the research program by June -- if I 25 l
I ALDERSoN REPORTING COMPANY,INC.
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remember right, originally this research was going to be 2
available a little sooner -- then how will you be in a 3
position to recommend actions over this summer?
4 MR. HANAUER:
We recommend actions based on 5
what we know and either confirm them or recommend 6 different actions when we know more.
7 HH. DENTON:
What I'm determined to do here is 8 not to let this turn into an ATHS situation, in which 9
the need for additional information postpones the to decision.
So I've told the staff I want the decision in 11 June, recognizing there will be a lot of research 12 ongoing and we'll have to take that into account at the 13 time.
14 But I think when we get into these very 15 complicated issues there is a tendency to avait the one 16 bit of information.
We might have 90 percent of what we 17 need to know by June, so we vill try to recommend 18 something.
We vill talk to the Commission in June, 19 based on what we know at that time, recognizing there's 20 still work being done, and we vill just have to take a 21 snapshot of it at the time.
But I am concerned that to 22 avait any given research might mean pushing the initial 23 position development on out for another year.
i 24 COMMISSIONER BRADFORD:
Am I right in thinking 25 that research han slipped?
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CHAIRMAN PALLADINO:
Has what?
2 COHNISSIONER BRADFORD:
Ha s slipped.
3 HR. HANAUER:
A small amount.
They still 4 project finishing on time in O'ctober.
Perhaps -- I 5 don 't think those people are here.
6 CONNISSIONER BRADFORDs Okay.
Wh y don't you 7 go back.
8 MR. DENTONs It would be desirable certainly 9 to have it all available as early as possible.
10 NR. HANAUERs We looked in some detail at 11 whether we could accelerate it to Hay or June, and the 12 answer is no, not and do an acceptable job.
We worked 13 pretty hard on that.
14 (Slide.)
15 Number 14 gives the longer-range heavy section 18 steel experimental and theoretical work which has been 17 put in place to deal with pressurized thermal shock.
18 There have been a number of thermal shock experiments 19 already in the heavy section steel technology program, 20 but they have not yet tested experimentally the 21 combination of applied stress and thermal stress.
And 22 so there is a series of small intermediate scale 23 experiments, including some integral experiments with 24 model vessels.
25 COMMISSIONER ROBERTS:
Where is that done?
l i
ALDERSON REPoMTING COMPANY,INC,
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HR. HANAUER:
Oak Ridge.
They already have a 2 boneyard of vessels that have been tested to destruction 3
in various ways and have accumulated a large amount of 4 lore in that area.
5 CHAIRNAN PALLADINO:
Steve, how did you arrive 6 at this test program being the right one?
The reason I 7 ask is, I heard people say different things about our 8
research program in this area.
Was this a battle of 9 experts?
Was it the staff that decided this was the 10 right thing to do?
11 HR. HANAUER:
All of the above.
The 12 contractor and the staff and some outside experts have 13 all been working on this.
14 CHAIRMAN PALLADINO:
The reason I ask, for 15 example, Dr. See at Lehigh says we really haven't gotten to a sound approach that we ought to have, and he is 17 getting the National Academy or some connittee at the 18 National Academy to look at what we are doing and come 19 up with a proposal.
And I was just wondering to wha t 20 extent people such as his have impacted on our program.
21 MR. HANAUER:
We have talked at some length 22 with Dr. See.
It's not in my own area.
Let me 23 characterize what I understand and then ask for 24 amplification.
25 My understanding of this point is that one has l
[
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to start with the fundamentals of solid state physics 2
and metalurgy in order to make sure that all modes of 3
failure on this microscopic and sacroscopic scale have j
4 been properly accounted for.
Our approach, lacking this 5 type of fundamental knowledge, has been with larger j
e scale engineering experiments under representative 7 conditions and fracture mechanics type characterizations 8 of the material properties and of the fracture modes.
9 We believe there is a great deal of both to theoretical and experimental justification for this.
11 But we think if the right kind of more fundamentally 12 based study can be done we would like to ree it, pending 13 some real proposal that we can review.
l 14 Mr. Randall again, perhaps.
15 NR. RANDALLs I was going to pass it off to to the man who runs the progra m.
17 (Laughter.)
18 HR. VAGINS:
I am Nel Yagins, program manager 19 of the HFSC program.
20 Professor See is a fundamentalist and has a 21 certain viewpoint.
It's unfortunate, though, that 22 approaching our problems from that direction may give an 23 answer, but it may be 15 or 20 years from now.
That's 24 my opinion.
l Also, I don't hesitate to say that I think 25 l
ALDERSoN REPORTING CCMPANY. INC, I
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it's the opinion of the vast preponderance of the pe o ple 2
working in the area of fracture mechanics in this 3
country.
We have made great strides in the last 15 i
4 years in fracture mechanics and we are continuing to 5 aake strides.
I do not agree that Dr. See's approach is a practical.
I further would state almost un equivocally 7
that you will not get answers in any kind of reasonable l
8 time f rame.
9 CHAIRMAN PAL 1ADINO:
We're not trying to get to you to evaluate the proposal, because I'm not sure we've j
11 got a proposal.
I'm just trying to see whether the i
12 various points of view have been factored in.
13 NH. VAGINS:
We have looked at it and in fact 14 over the years have made many attempts to integrate the 15 fundamental micro-structure approach to f racture 16 sechanics and have found it generally unsuccessful.
If HR. HANAUER.
In this connection, in order to 18 augment the substantial staff resources already working 19 on this, we are just finalizing a contract with Pacific 20 Northwest Lab to put together a multi-disciplinary team, 21 of which your friend and mine Spence Bush is a member, 22 to work with us and also to look over our shoulders in a 23 somewhat independent way, and also to organize a team of 24 technical outside specialists to act as peer review for 25 what we are doing.
l l
1
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The time scale involved makes it in our 2 opinion especially important that we get some 3 independent look at this set of requirements that we 4 intend to come up with.
5 CHAIRMAN PALLADIN0s Incidentally, if there 6 are good proposals for fundamental work that people 7 agree ought to be done, I would not necessarily dismiss 8 it because it takes a long period of time, because these 9 problems have a way of persisting for a long period of 10 time.
11 EH. HANAUERs I don't think we were dismissing 12 it.
13 CHAIRHAN PALLADIN04 I know you weren 't 14 dismissing it.
I just said that because my silence may 15 have led you to believe otherwise.
16 C00HISSIONER AHEARNEs I don't recall our 17 research program ever being faulted on that ground.
18 (Laughter.)
tg MR. DENTON:
I think this concludes our 20 presentation.
We are about three-quarters of the way 21 along in a program we set out to accomplish last year.
22 We have had several meetings with the ACRS and with 23 industry.
We are devoting I think over ten people, ten 24 man-years, to th e resolution of this within the NRR 25 budget, and there are millions of dollars going to the ALDERSoN REPCRTING COMPANY,INC,
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59 1
research program.
2 So it is a high priority USI and we do intend 3
to meet our June date with the best position we can give 4 you on these factors that remain to be assessed.
5 MR. HANAUERs Please say summer.
6 (Laughter.)
7 COMNISSIONER AHEARNEs Just like spring was a 8 long time coming in Washington, and summer may also?
9 MR. HANAUER:
Not too long, but summer is to easier than June.
11 (Laughter.)
12 CHAIRNAN PALLADINO:
Are there any particular 13 points that have not come out that maybe we ought to 14 address particularly to the industry people?
I know of 15 one at least.
16 MR. HANAUER:
Well, the thing I would hope you i
17 would learn from the industry is, first of all, a 18 delineation of the industry program in this area, both Ig in the owners groups and the vendors, and also the 1
20 Electric Power Research Institute.
Since the most l
21 difficult areas are the areas of event sequences and 22 f ailures of operator actions, I would invite you to 23 explore the industry spokesmen's viewpoints on what 24 should be done and what should be the conclusions, if 25 they have any, in these areas.
ALDOSoN REPORTING COMPANY. INC,
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There is one substantial program that the 2
industry is pursuing on the feasibility and cost of 3
annealing these vessels if it should turn out to be 4 necessary.
I information this program is essentially 5 completed and we are to see a report in a short time.
e Maybe they will be able to tell you about it.
7 CHAIRMAN PALLADIN0s Do you know whether ther 8 are doing any work on looking at, making changes in the 9 perimeter of the core, and what impact that might have 10 on the specific plants or generically?
11 MR. HANAUER:
I guess 'I don 't know.
12 CHAIRMAN PALLADINO:
Well, we could ask them.
13 MR. HANAUER:
Yes.
There is work in the 14 industry.
Whether EPHI is doing it, I can't tell you.
15 CHAIRMAN PALLADIN0s I guess I'm trying to to think of questions.
I guess they are the ones to 17 explore with the question of how dif ficult it would be 18 to warm ECCS and wha t consequences it would have.
19 MR. HANAUER4 Yes, sir.
That's on our list.
20 They have pretty much dismissed it on the basis that 21 it's not needed.
We have to explore it some more.
22 MR. DENTON:
I guess I would explore one 23 aspect, too.
This issue is different than many 24 unresolved safety issues in that the risk is not the 25 same year af ter year.
This risk is one which as each ALDERSoN REPORTING COMPANY,INC,
W 61
~
year passes a certain amount of more radiation has 1
.f 2
occurred and you may have foreclosed some alternatives.
3 So it 's not like many issues of risk that tend to stay j
4 the same year after year, and so they do have the option i
5 that if this area is not going to resolve itself cleanly j
6 to take certain steps to prevent further embrittlement, 7 for example by using lov leakage cores.
8 It will be interesting to see how they 9
approach this probles, because even in the year we have 10 taken to try to resolve it we have perhaps a ten-degree
[
11 shift in some of the vessels.
12 CHAIBHAN PALLADINO:
Does this low leakage 13 core concept have to be institued early, or is it a 14 concept that is workable even with cores that are well 15 along in their lifetime?
16 MR. HAN AITER s It's workable any time.
There 17 is a fairly long lead time involved.
You have to plan 13 far.shead in your fuel management program.
You have to 19 order the right enrichment.
If you're going to order 20 ' dummy f 91 or depleted fuel, you have to order it.
It 21 has to be manufactured.
You probably have to
.l 22 recalculate all the accidents again.
There is a l
23 regulatory burden on this.
24 COMMISSIONER AHEARNEa And the advantage of 25 doing it decreases, doesn't it?
ALDetSoN REPORTING COMPANY. INC.
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NR. HANAUERs It decreases.
But if you do 2
something fairly severe, if you do something which 3 reduces the flux by a factor of ten you essentially stop 4
the embrittlement in its tracks and you only get three 5 more years worth in 30 more years of operation, so even 6
if you are halfvar you can essentially stop it.
7 CONNISSIONER AHEARNE:
Are the core changes 8 that are being discussed in this country factors of 9
tan?
10 NR. HANAUER:
No, sir.
They are typically 30 11 percent to a factor of 2 degrees.
That has much less 12 stress.
13 But in the high fluence core,
-- in a high 14 fluence core that may be substantial.
15 CHAIRMAN PALLADIN0s Steve, you f righten me a 18 little bit s' ten you say all analyses and everything has 17 to be done.
Is there no var of scoping the problem and 18 saying, well, with this reduced flux thus and so can 19 take place?
20 NR. HANAUERs Oh, you can do that, all right.
21 But in the meantime you have changed the hot channel 22 factors and the behavior of cores in reactivity 23 transier.ts, and that has to be looked at to make sure 24 'you didn 't make something else worse.
I 25 (At 11:25 a.m.,
Commissioner Gilinsky entered j
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the room.)
2 CHAIPMAN PALLADINO:
It's still frightening.
3 MR. HANAUERs That's the expense of any 4 unforeseen reload.
5 MR. DENTONs I think that would be a good 6
topic to explore with the industry today.
7 COMMISSIONER BRADFORD:
Let se ask you to 8
review one thing f or me, and if you covered it before I 9 came in just say so and I'll look at the transcript.
A 10 year ago when the staff came in -- not quite a year ago, 11 nine months ago -- the basic proposition was that at 12 least in most plants the worry was something might have 13 to be done within a year.
The conclusion now is, as to 14 the Bancho Seco type of event, we have at least several 15 years more leeway.
16 Can you pinpoint for say the top four on your 17 list -- Fort Calhoun, Maine Yankee, Calvert Cliffs and 18 Bobinson --what it is that's changed?
19 HB. HANAUERs I don't think anything has 20 changed except perhaps our understanding.
21 COHNISSIONER BRADFORDs But as to what factors 22 has your understanding changed enough to produce the 23 additional year's time?
24 MB. HANAUERs In the first place, I was pretty 25 far from it a year ago.
But in reading the briefing ALDERSoN REPORTING COMPANY,INC, 400 MAGINIA AVE., S.Wo WASHINGTON D.C. 20024 (Ei) 584-2346
64 1
materials a year ago, I don 't get the same lapression 2
you did.
My impression of those briefing materials --
3 and I will ask Tom Murley to be sore specific -- was s
4 that we surely had a year and we didn't know whether we 5 had any more.
6 COMMISSIONER AHEARNE:
I would have to say 7 that was the impression I had, tha t the ph rase they kept 8 on using was "at least a year."
9 COMMISSIONER BRADFORD:
I don't have the to material in front of me.
It just seemed to me there 11 were calculations that showed beyond a year some of the 12 RT-NDT temperatures reached a height that was 13 troublesome in light of what had occurred in Rancho 14 Seco.
15 MR. DENTON:
We thought back at that time that 16 ve did have at least a year.
It wasn't that it had to 17 be done within a year.
We had also talked about 18 temperature limits of perhaps 300 degrees and there were 19 plants that, if the shifts continued, it wouldn't take 20 very long to reach 300 degrees if we started with 290.
21 COMMISSIONER BRADFORDs I just thought that 22 was the point, that some of those plants were likely to 23 get over 300.
24 MR. DENTON:
But we tend to pull the 300 out 25 of the air without having any kind of detailed ALDERSoN REPORTING-COMPANY,INC, m.
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information.
Now that we have got --
2 COMMISSIONER BRADFORD:
So what you're saying 3
is the 300 degrees is no longer a determining factor.
4 MR. DENTON:
We may eventually pick some 5
temperature in the criteria to be used.
But the 300, 6
when we picked it, we didn't have the benefit of the 7 plant-specific responses as to what the properties were 8
and how they responded to a Bancho Seco event.
9 COMMISSIONER GILINSKY:
I thought you were to also looking at events more severe than an Rancho Seco.
11 NR. DENTON:
Yes.
12 N'H. HANAUER:
He are, and the submittals have 13 acre severe events.
And with the assumptions they make 14 they are also all right.
And that is the detailed 15 review that we are still involved in.
16 CHAIREAN PALLADINO:
I think Tom Hurley had a 17 comment.
18 HR. MURLEY:
Could I add a point of Ig perspective to that?
Last year, as you recall, we had 20 just done the Rancho Seco transient and applied it to i
21 some of these older vessels, and we were faced with a 22 half a dozen that were up in the 280-290 RT-NDT range.
23 As best we knew it then -- and I think the staff will 24 bear me out -- we thought tha t was conserva tive, but we 25 didn't have it in hand at the time.
ALDER $oN REPORTING COMPANY,INC, 400 VIRGINIA AVE. S.W. V!ASHINGToN, D.C. 20024 (202) 554 2345
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The year that's passed has been used to good 2 advantage in the sense that the industry in particular 3
has gone to their archive samples and vessel fabrication 4
techniques and found that the initial RT-NDT's were 5
lower than we were using, and the analysis of the 8 embrittlement rates showed that they were less than we 7 vere using.
8 So both of those together show that the best 9
estimate values today are much less than our best 10 estimates of a year ago.
So I think that is the 11 difference in perspective.
12 COHNISSIONER BRADFORD:
Were you using best 13 estimates a year ago, Tom, or were you using 14 con se rva tive?
15 MR. MURLEY:
We were using what today we would to call conservative, but a year ago th ey were our best 17 estimates
-- well, I who had to get up and give the 18 talk thought they were the best estiantes, the Reg Guide 19 1.99 curves.
There vece not alternate 1.99 curves a 20 year ago, were there, to my knowledge.
So in that sense 21 they were still the best estimates.
But we today knov 22 that they were conservative.
23 CHAIRMAN PALLADIN0s Any other questions?
24 CORNISSIONER BRADFORD:
The answer to my 25 question, then, is that the best estimate RT-NDT numbers i
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have fallen quite a lot in the last nine sonths?
2 MR. HANAUERs That's true.
3 COMEISSIONER AHEARNE:
And also, last year 4
they said repeatedly there is at least a year.
5 COHNISSIONER BRADFORD:
But they also were 6
using a 300-degree number of being the point of concern, 7 and they 8
CONHISSIONER AHEARNE4 They made it clear that 9
was an arbitrary number.
10 CONNISSIONER BRADFORDs I don't think ther 11 did.
And they had plauts that crossed that number in 12 about a year or two years time.
13 CHAIRMAN PALLADINO Well, I gather you still 14 feel that we have problems.
15 MR. DENTON:
I feel and still continue to 18 think no immediate action is required today on these, 17 and that nothing is going tC lead me to recommend action 18 in the next. nonth on this issue because of the slow rate 1
l 19 of change that is occurring and the confidence I have 20 got about certain types of transients, anyway, that we 21 can wait until the date we oricinally selected to 22 complete the studies that are ongoing and make our 23 recommendation then.
24 CHAIRMAN PALLADINO:
This summer, you mean?
f 25 MR. DENTON:
Yes.
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CHAIRHAN PALLADINO:
You may make 2
recommendations on prudent action.
3 ER. DENTON:
Yes.
I think the forecast, as 4 Steve said, is we would expect it to be focused on this 5 question of operator action and adequacy of procedures 6 as a key area, to see in place are those procedures and 7 training as actually presumed to be in place when these 8 analyses were done.
9 CHAIRMAN PALLADINO:
Night you be including 10 such things as warning the ECCS vater?
I'm not saying 11 you should or would, but might. you?
Is tha t being 12 looked at, in other words?
13 ER. DENTON:
It was originally high on our 14 list of possibilities.
I guess I would have to ask 15 Steve how he sees that one.
l 16 NR. HANAUER:
It's possible, but it doesn ' t 17 seem like a very high candidate at the moment.
18 CONNISSIONER GILINSKY:
Any others?
19 CHAIRNAN PALLADIN0s How about lov leakage 20 cores?
21 NR. HANAUER:
That seems to be higher on the 22 list.
NH. DENTON4 I'm more f avorably inclined l
23 24 toward high leakage cores, because they do have a 25 potential to slow down and diminish the rate of ALDERSoN REPORTING COMPANY. INC, s
S 69 1
increase, these low leakage cores, and take some of the 2
plants that do expect to operate for another decade or 3
two.
I think it is important not to let it climb, 4 because we may have a different assessment of the l
5 situation a few years from now than we would have today, 6
and the lower we can keep the temperatures and the 7 embrittlement the better off we will be.
8 CHAIRMAN PALLADINO:
Well, do I also gather as 9
another observation from your report that you expect to 10 have most of the basic research -- most of the research 11 program that you have outlined here completed some time 12 in mid '83 or late '83?
Is that right?
13 MR. HANAUER The mediua term research, the 14 systems calculation that I discussed, is due toward the 15 end of
'82, and therefore it is consistent with that 16 period.
The heavy section steel work -- it tak'es a long 17 time to irradiate thick specimens and so on -- is a f
18 multi-year program.
39 CHAIRMAN PALLADINO:
Confirmatory type?
20 MR. HANAUER:
Yes, sir.
21 CHAIRMAN PALLADINO Okay.
Any other 22 questions or comments?
23 (No response.)
24 CHAIRNAN PALLADINO Well, we thank you very 25 auch and we look forward this afternoon to hearing i
l l
ALDERSoM REPORTING COMPANY. INC, 400 VIRGINIA AVE, S.W WASHINGTON. D.C. 20024 (202) 56&2348
6 70 further on the question from representatives of AIF and 1
2 EPRI.
We stand in recess.
3 (Whereupon, at 11:35 a.m.,
the meeting was 4 adjourned.)
5 6
7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 23 24 25 l
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