ML20148P752
| ML20148P752 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1988 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| REF-10CFR9.7, REF-GTECI-A-44, REF-GTECI-AE, TASK-A-44, TASK-OR NUDOCS 8804120113 | |
| Download: ML20148P752 (85) | |
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9 UNITED STATES OF AMERICA l
NUCLEAR REGULATORY COMMISSION i
Title:
BRIEFING OM PROPOSED FINAL RULE ON STATION BLACKOUT
--PUBLIC MEETING--
Location:
Washington, D.C.
i Date:
Thursday, March 31, 1988
(
Pages:
1 - 73 Ann Riley & Associates Court Reporters 1625 i Street, N.W., Suite 921 Washington, D.C. 20006 y
(202) 293-3950 4
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i 1
D i SC LA I M ER 2
3 4
5 0
This is an unofficial transcript of a niee t i ng of the 7
United States Nuclear Regulatory Commission held on 8
March 31, 1988 in the Commission's office at 1717 H Street, 9
'li. W., Washington, D.C.
The meeting was open to public 10 attendance and observation.
This transcript has not been i
11 reviewed, corrected, or edited, and it may contain 12 inaccuracies.
s 13 The transcript is intended solely for general 14 informational purposes.
As provided by 10 CFR 9.10S, it is 15 not part of the formal or informal record of decision of the 16 matters discussed.
Expressions of epinion in this transcript 17 do not necessarily reflect final determination or beliefs.
No 18 pleading or other paper may be filed with the Commission in l
1 19 any proceeding as the result of or addressed to any statement 20 or argument contained herein, except as the Commissio'n may 21 authorize.
22 23 l
24 j
i 25
1 l
l l
1 UNITED STATES OF AMERICA 2
NUCLEAR REGULATORY COMMISSION 3
4 BRIEFING ON PROPOSED FINAL RULE ON 5
STATION BLACKOUT 6
7 PUBLIC MEETING 8
9 Nuclear Regulatory Commission 10 Room 1130 11 1717 H Street, N.W.
12 Washington, D.C.
13 March 31, 1988 14 15 The commission met in open session, pursuant 16 to notice, at 10:02 a.m.,
the Honorable LANDO W.
17
- ZECH, JR.,
Chairman of the Commission, presiding.
18 19 Commissioners Present:
20 21 LANDO W.
ZECH, Chairman 22 THOMAS M.
ROBERTS, Commissioner 23 FREDERICK M.
BERNTHAL, Commissioner 24 KENNETH ROGERS, Commissioner 25 KENNETH M.
CARR, Commissioner
-. --. ~ -..
2 r
1 2
S'taff and presenters. seated at table:
3 4
S.
CHILK - SECY 5
V.
STELLO - EDO 6
W.
PARLER - OGC 7
T.
SPEIS 8
W.
MINNERS 9
A.
SERKIZ 10 A THADANI 11 F.
ROSA 12 13 Audience Speakers:
14 15 P.
BARANOWSKY 16 A.
RUBIN 17 R.
BAER I
18 19 20 21 22 4
23 24 25 s
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1 P R O C E E D I N G S 2
CHAIRMAN ZECH:
Good morning, ladies and 3
gentlemen.
Today the Commission will be briefed by 4
our Offices of Research and Nuclear ~ Reactor 5
Regulations on a proposed rule to require that 6
light-water reactors be capable of withstanding a 7
station blackout for a specific period of time.
8 A station blackout is a total loss of both 9
off-site power and on-site emergency AC power 10 systems.
11 The proposed requirement is based on 12 information developed under the Commission's study of 13 unresolved safety issue A-44 of station blackout.
14 The Commission designated station blackout 15 an unresolved safety issue in 1980, and studies were 16 initiated to determine whether additional safety 17 requirements were needed.
18 In March, 1986 a proposed rulemaking was 19 published in the Federal Register.
Based on the 20 Staff analynis of comments received, the proposed 21 rule has now been finalized and is ready to be issued 22 subject to Commission approval.
23 During the Staff presentation, we would be 24 interested in hearing about the revision to the 25 regulatory backfit analysis and the associated
1 4
'l regulatory guide for a review standard for the 2
acceptance of the specific blackout duration.
3 This is an information briefing.
The 4
Commission will not be voting on the final rule 5
today.
I understand that copies of the slides are 6
available in the back of the room.
7 Do any of my fellow Commissioners wish to 8
make any opening comments?
9
[No response.]
10 CHAIRMA!! ZECH:
If not, Mr. Stello, would 11 you proceed, please.
12 MR. STELLO:
Thank you, Mr. Chairman.
In a 13 moment I'll turn to Dr. Speis to begin the 14 presentation and to introduce others here at the 15 table with us today.
16 I thought I'd make a few points to begin 17 with.
Station blackout clearly has been with us for 18 some time now, and it is an issue that has been 19 recognized as a significant contributor to core risk.
20 In fact, those plants which are the latest plants the 21 Commission has done a fairly thorough analysis of 22 risk presented in flUREG 1150 that the Commission is 23 aware of, shows that even though the core melt j
24 frequencies are getting very low, the station 25 blackout remains a dominant contributor to risk.
l
9 5
1 With that background, we are proposing that 2
there are two approaches one can use to deal with 3
station blackout.
One approach is to show, depending 4
on the sources of power and site specific issues, if 5
you can cope with a station blackout for a specific 6
period of time that's acceptable or, on the other 7
hand, if you add additional sources of power to the 8
site, that's also an acceptable approach.
9 What the Staff will be presenting is why we 10 believe that's a correct way to go, and we are going 11 to suggest to the Commission *. hat we think because of 12 the issue that is raised that station blackout, even 13 when malfrequencies get to be low, remain a 14 significant contributor to risk and there are other i
15 generic issues that could be resolved, in fact, if 16 you had an additional source of power that the Staff 17 suggest, then the Commission ought to say in its rule 18 that those two options are.there but it prefers that 19 the solution of station blackout be by the addition 20 of an additional power source to the site.
21 And we'll identify that in the briefing and 22 have some particular words to suggest that Commission 23 may wish to consider' adding.
I think it's an 24 important consideration, and we'll get to.it in a 25 moment.
l
6 1
But that -- Dr. Speis, will you continue?
2-CHAIRMAN ZECH:
All right.
You may 3
proceed.
Thank you.
4 MR. SPEIS:
Mr. Chairman, Commissioners, to 5
my right I have Aleck Serkiz who has been the project 6
manager of this issue who will participate in the 7
discussion,, questions and answers.
r 8
Next, Minners, he's from the Office of 9
Resources, the Deputy Director of the Systems 10 Division; al.3 from the Office of' Nuclear Reactor 11 Regulation, we have Faust Rosa, Branch Chief of the 12 Electric Systems Branch, and Mr. Thadani, the 13 Assistant Director for Systems who'll give you the 14 NRR presentation.
15 Let me start by giving you -- can I have the 16 next viewgraph, please.
)
17 (Slide.]
18 MR. SPEIS:
In this viewgraph, I give you, 19 Mr. Chairman, the briefing that will give you the 20 dates.
We'll give you the briefing as Mr. Stello 21 said, it's in two parts.
The first part will deal 22 with the development of the rulo, the second part 23 will address the implementation of the rule.
That's 24 the part that will be provided by the Office of 25 Nuclear Reactor Regulation.
7 1
In my presentation, I will give you a 2
summary and background of the issue, I will summarize 3
the safety concerns associated with the blackout 4
issue, I will summarize the findings that we have put 5
together.
he have been working on the this issue for 6
the last three or four issues very extensively, as 7
you know.
8 We'll discuss the proposed resolution.
We 9
will discuss the benefits of the alternate AC power 10 source that Mr. Stello just mentioned to you which is 11 the preferred way of going, and go into some more 12 detail of the rule itself.
13 May I have the next viewgraph, please.
14 (Slide.)
15 MR. SPEIS:
Here we provide a summary and l
16 some background of where we are coming from.
As you l
i i
17 said, Mr. Chairman, a station blackout was designated 18 in a recent safety issue back in 1978.
The issue has l
19 been studied extensively since that time.
20 The issue has its origin basically in 21 operating experience and PRA studies, not only the 22
!!UREG 1150 studies, but mostly the studies that have 23 been done have identified station blackout as a i
24 contributor to risk.
l 25 Operational experience has been an important
'O l'
1 1
factor-in pushing us in this direction that we'll be 2
recommending to you today.
)
3 From 1968 to 1985 we had a large number of, I
4 something like more than 60 total loss of off-site 5
power events of a few minutes duration up to some 6
hours.
7 From 1976 to 1985, we had made hundreds of 8
diesel generator failures during testing as well as 9
actual demands.
10 And also from 1968 to 1985, we had the 11 number of station blackouts precursors involving 12 total loss of off-site power, most of them for a few 13 minutes, power was able to be restored.
14 So there is enough operational experience 15 that tells us that it's an important issue in 16 addition to the PRA studies that have been mentioned.
17 The other thing that tells us that this 18 issue is important is that it has severe 19 consequences, potentially severe consequences.
If 20 you lose power, you have limited capability of 21 removing core decar heat.
And of course in most 22 instances you lose compl'etely containment decay heat 23 removal.
24 We have found out that severe weather 25 conditions are a major contributor to loss of
~
9 1
off-site power; such weather conditions as 2
hurricanes, ice storms, tornados.
3 We have done extensive studies, as I said, 4
involving the total population of nuclear power-5 plants.
These studies have been documented in NUREG 6
1032.
From those studies, I have -- I'm sorry.
I 7
was jumping to the next viewgraph for sone strange 8
reason.
9 We had extensive interactions with the ACRS, 10 with CRGR.
The rule, as you said, Mr. Chairman, has 11 gone out for publi: comment, and the appropriate 12 comments have been incorporated.
1 13 We had extensive discussions with --
14 interactions with industry.
NUMARC sponsored the 15 working group composed of utility people as well as 16 technical consultants.
In fact they have put 17 together a document which has been identified as 18 NUMARC 8700 which provides the guidelines and 19 technical basis for addressing plant capability to i
20 withstand station blackout.
21 We have reviewed this document, and we have 22 found it acceptable with some exceptions which are 23 noted in the Reg Guide which I will discuss shortly.
24 NUMARC has agreed with these exceptions and 2S has commenced to conduct the workshops for utilities
)
10 1
1 to demonstrate the use of this document.
2 So it is our understanding that industry now 3
agrees with the way we are going about to resolve i
4 this issue.
5 MR. STELLO:
In fairness, I don't believe 6
the industry is aware that we are suggesting the 7
Commission add its preference.
I don't believe they 8
are aware of a particular issue before this meeting, 9
at least that's my understanding.
So the agreement 10 does not include any preference that the Commission 11 may have.
They are not aware of it.
12 COMMISSIONER ROGERS:
Are they in agreement 13 with the Rule?
14 MR. STELLO:
Everything except yes.
i 15 COMMISSIONER ROGERS:
They are in agreement 16 with the Rule?
5 17 MR. STELLO:
Yes.
18 MR. SPEIS:
With the two options.
And of 19 course one of the options is the alternate power 20 source, and Mr. Stelio is saying that is our 21 preferred option.
22 So we are here today to recommend that you 23 gentlemen approve the issuance of the final rulo 24 which would require all LWRs to be able to withstand 25 a station blackout for a specified duration and
4 11 1
maintain core cooling during that period.
2 I will discuss later on what are the -- what 3
is the specified rates and where it derives from.
4 Again the goal of this role is to reduce the 5
frequencies of occurrence of core damage from station 6
blackouts.
We feel that if this rule is implemented 7
it will reduce the contribution of station blackout 8
to core dominance by at least a factor of ten on the 9
average.
10 COMMISSIONER BERNTHAL:
Let me ask a 11 question about the fundamental assumption here with 12 respect to risk from blackout.
13 Is that a deterministic number in the sense 14 that you have not tried to carry out perhaps 15 independently an emperical study to see whether that 16 matches what might be a normally deterministic 17 methodology, if you understand what I'm saying?
18 MR. SPEIS:
I understand, yes.
19 COMMISSIONER BERNTHAL:
There are enough 20 events 21 MR. SPEIS:
Yes.
I
\\
22 COMMISSIONER BERNTHAL:
by now that 23 MR. SPEIS:
I think this issue, even without 24 rates, we have enough statistics and we know enough 25 about the consequences of station blackout to make us
12 1
1 probably propose the same thing.
2 But I think this is an ideal issue where'we 3
are able to compare the statistics and the 4
deterministic analogies with safety goals, and more 5
or less they've met both of them, okay, using.a
~
6 safety goal type of approach and using the i
7 experience, the operational experience, the i
8 deterministic analysis, consequence 7.nalysis, we're l
9 able to reach the same conclusions.
So one 10 re-inforces the other, basically.
t 11 So it's an ideal issue where the safety I
12 goal,,in fact one will come in the future to discuss b
13 implementation of the safety goal, we'll give you 14 this as an example of how one can go about 15 implementing the safety goal.
16 COMMISSIONER BERNTHAL:
So you've survoyed 1
17 all of the station blackout events, or perhaps l
18 precursor station blackout events, and carried out a 4
]
19 statical analysis of that l
1 i
l 20 MR. SPEIS:
Yes.
21 COMMISSIONER BERNTHAL:
independently of l
22 a calculation and deterministic procedure that of 23 course we normally do for PRA?
4
{
24 MR. SPEIS:
All of that is discussed in this 25 NUREG that I mentioned earlier, 1037.
13 1
COMMISSIONER BERHTHAL:
And the results are 2
rather similar --
3 MR. SPEIS:
Very similar.
4 COMMISSIONER BERNTHAL:
-- and they both 5
indicate that the severe core damage frequency, well, 6
it says here 10 to the minus 4,
10 to the minus 6.
7 MR. SPEIS:
Let's go to the next viewgraph 8
so we'll address a little bit those numbers.
9
[ Slide.)
10 HR. SPEIS:
I'm sorry, I was racing ahead 11 earlier in the core assembly information here, but 12 let me I won't repeat the first one as Mr.
13 Chairman mentioned what station blackout is all 14 about.
15 Again the genesis of this issue is both the 16 operational experience and the extensive PRAs.
The 17 potential is severe consequences involving limited 18 decay heat removal as well as no containment heat 19 removal; I mentioned the severe weather conditions.
20 Again from all the studies that we have done 5
21 involving the total population of nuclear power 22 plants, we have estimated the range of frequency of i
23 station blackout to be somewhere to be 10 to the i
I 24 minus 3 to 10 to the minus 5 per reactor year.
That 25 is station blackout.
l
\\
l
14 1
Now the contribution of station blackout to 2
the total core damage, has been estimated to be i
3 somewhere between 10 to the minus 4 and 10 to the i
4 minus 6.
l 5
And this is what I said earlier that the 6
goal of the resolution is to reduce the frequency of 7
station blackout contribution and hopefully this 10 8
to the minus 4 number will go to 10 to the minus 5,
9 okay, so that is the goal.
10 COMMISSIONER BERNTHAL:
I guess the thing 11 that's bothering me a little bit is that you have a i
12 range of frequency of station blackout:
Ten to minus
)
13 3,
10 to the minus 5.
That means that for a 14 population of a hundred reactors, we should only see 15 one every ten years, right?
And that seems like i
16 that's wildly out of sync with what we are really 17 seeing.
18 MR. SPEIS:
This is a complete station 19 blackout.
This is not loss of off-site power.
Let's 20 make sure, you know -- loss of off-site power in the 21 average of the United States is something like
.1 per 22 year.
This is a complete station blackout.
23 COMMISSIONER BERHTHAL:
Okay.
But you still 24 say you believe that I mean in the most 25 favorable case, the 10 to the minus 3 means that for
15 1
a population of 100, it should happen once every ten 2
years.
And you're saying that somewhere between once 3
every ten years and once every thousand years --
4 MR. STELLO:
Well, are you using 10 to the 5
minus 3 as the measure of the sample in the industry?
6 The range is 10 to the minus 3 to 10 to the minus 7
4 I mean 10 to the minus S.
8 COMMISSIONER BERNTHAL:
Yes.
9 MR. STELLO:
The average of the plant is 10 on the order of more like 10 to the minus 4.
11 COMMISSIONER BERNTHAL:
Fine.
12 MR. STELLO:
Okay.
And with 100 plants 13 COMMISSIONER BERNTHAL:
Once every 100 14 years.
15 MR. STELLO: Once every 100, and if you 16 look 17 COMMISSIONER BERNTHAL:
Which bolsters my 18 point.
19 MR. SPEIS:
We've had three or four so far 20 in the total operational experience.
)
21 MR. STELLO:
Which is consistent with that 22 number.
2 23 MR. SPEIS:
Which is 1500 to what, 1700 24 years?
25 MR. STELLO:
About 1500 reactor years of
16 1
experience that you would have expected 2
COMMISSIONER BERNTHAL:
Worldwide?
3 MR. SPEIS:
No.
No.
United States.
United 4
States.
5 COMMISSIONER BERNTHAL:
United States?
6 MR. SPEIS:
Yes.
7 MR. STELLO:
So it's inconsistent with 8
MR. SPEIS:
It's consistent.
9 MR. STELLO:
-- the numbers.
The frequency 10 range that you have, the rate is reasonably 11 consistent with the experience that you've had.
12 COMMISSIONER BERNTHAL:
How many actual r
13 station blackout events have we had?
14 MR. SPEIS:
Okay.
We have had four.
I'm 15 familiar with four of them.
They are a few minutes.
16 The longer one was the the other ones were a few t
17 minutes and we were able to restore I mean the 18 plants were able to restore power.
19 COMMISSIONER BERNTHAL:
So we've had four 20 events in 1300 odd reactor years.
That doesn't 21 comport with these numbers.
You're saying we have 22 MR. STELLO:
Yes.
23 COMMISSIONER BERNTHAL:
-- four station 24 blackout events.
25 MR. STELLO:
Right.
17 1
COMMISSIONER BERNTHAL:
1300 operating 2
reactor years.
3 MR. SPEIS:
It's more than 13, it's 17.
4 MR. STELLO:
About-1500.
5 COMMISSIONER BERNTHAL:
Well, okay.
1500.
6 MR. STELLO:
Right.
7 COMMISSIONER BERNTHAL:
Let's s a'y 1600,.i t 8
makes it easy here.
That means one in 400.
9 CHAIRMAN ZECH:
You've got somebody here 10 that wants to 11 MR. BARANOWSKY:
Could I clarify something.
12 My name is Pat Baranowsky and I'm the author of the 13 report that everybody is discussing the statistics 14 on.
15 The 10 to the minus 3 number is based on 16 blackouts of about a half-hour duration or longer.
17 So all the ones that we've had are lesa than a half 18 hour2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />.
19 So when Themis says there have been four 20 precursors which is what he'said is correct, they're 21 not exactly the kind of blackouts that we're talking 22 about in terms of high risk because they have been 23 less than a half hour.
24 COMMISSIONER BERNTHAL:
So these four were 25 all lesa than a half hour
18 l
l 1
MR. BARANOWSKY:
That's right.
2 COMMISSIONER BERNTHAL:
and the numbers, f
3 10 to the minus 3 to 10 to the minus 5 refers to 4
station blackout longer that one half hour?
I 5
MR. BARANOWSKY:
Right.
6 CHAIRMAN ZECH:
We haven't had any longer 7
than a half hour; is that right?
8 MR. BARANOWSKY:
No full blackouts that I
)
9 know of longer than a half hour.
10 CHAIRMAN ZECH:
All right.
11 COMMISSIONER BERNTHAL:
Okay.
12 CHAIRMAN ZECH:
All right.
Thank you.
Go I
i 13 ahead, please.
l j
14 MR. SPEIS:
Consistent with what Pat said, 15 the extended duration blackouts, that is more than 16 two hours, are the ones that we are mostly concerned, 17 Item No. 6 on the viewgraph.
18 In general, this is our assessment, you 19 know, that most plants possibly are able to cope 20 could be able to cope with blackouts for around two 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />, but we need to some evaluations to confirm 22 this.
23 At present there is no regulatory 1
24 requirement for plants to cope with station blackout.
t a
25 May I have next viewgraph, please.
4
19
,1
[ Slide.)
2 MR. SPEIS:
Here we summarize some of the 3
findings.
The key point here is that everything is 4
variable.
The reliablity of on-site emergency AC 3
power systems varies considerably.
The f r a t : ~. s here 6
are the variety of plant designs and configurations, 7
the emergency diesel generator reliability i
8 configuration.
9 What I mean by configuration, Mr. C h a i r m.s n,
10 is how many diesels you have and how many you need 11 for decay heat.
For example, some plants have three 12 and they need two, some plants have three and they 13 only need one.
So that's an important factor.
i 14 Common cause failures, design errors, human errors, 15 and things of that sort.
16 Frequency and duration of off-site power 17 also varies considerably.
Site is an important 18 consideration which of course is affected by the i
19 weather, the grid design configuration, and plant 20 specific factors associated with the CCR design, 21 transmission lines.
22 I've taken all of these things into 23 account then core damage frequency that can vary 24 considerably from plant to plant.
As we said 25 earlier, that can vary anywhere from 10 to the minus i
.20 1
4 to 10 to the minus 6 per reactor year which is 2
sources of magnitude.
3 Important factors here are the l
4 susceptability to station blackout and of course the 5
ability to withstand the loss of all AC power.
6 Here we're talking about specific _ plant 2
attributes.
For example, the ability of the reactor 8
coolant pump seal to' withstand station blackout, the 9
capacity of water, electrical power, air systems, all 10 these are important attributes that tell you about 11 the capability of a plan.t to withstand station 12 blackout.
13 Again our proposed resolution considers 14 plant unique characteristics and provides a cost 15 effective way of achieving a plant specific solution.
16 Our approach has been to look into this in a 17 grad (d way and the plants that have less reliable 18 power sources because of location or configuration, 19 they'll have to do more or less again depending on 20 how good or how bad they ax e.
21 So we don't want to come up with a blank 22 regulatory requirement that we'll treat all plants 23 equal.
Plants that are better should do less; plants 24 that need to do more, should do more.
So that has 25 been our approach.
Okay.
21 i
1 The next viewgraph goes into some more 2
details of the proposed resolution itself.
3 (Slide.]
P 4
MR. SPEIS:
Again the final solution 5
consists of a rule and a regulatory guide.
We are 6
proposing to amend 10 CRF 50 by adding Section 50.63, 7
Loss of All Alternating Current Power, which requires 8
that all plants be able to cope with station blackout 9
for specified duration.
10 Again this is the graded approach.
This 11 specified duration, I will discuss it later on, but I I
]
12 want to say right now that it will be based on plant 2
13 specific characteristics which affect the reliability 14 of both the on-site and off-site power system.
i j
15 An alternative AC power source is an 16 acceptable option.
As Mr. Stello said already, we i
j 17 prefer the alternate AC power source due to i
18 additional safety benefits.
19 Also as part of ;he resolution. we are 20 proposing to issue Regulatory Guide 1.155 which 21 provides general guidance of how to comply with the l
22 rule itself.
The guidance addresses such things as i
j 23 severe weather categories, required levels of
)
24 emergency diesel generator reliability, and other a
25 related assumptions.
22 1
Also it provides guidance on the station 2
blackout analysis, how does one go about 3
developing -- deciding the duration which depends on 4
these off-site and on-site factors.
3 Also it provides guidance on the use of the 6
alternate AC sources.
7 And also it 8
COMMISSIONER ROBERTS:
Pardon me.
9 MR. SPEIS:
Yes, sir.
10 COMMISSIONER ROBERTS:
What do you mean when 11 you say QA considerations?
12 MR. SPEIS:
What type of quality assurance 6
13 has to be considered.
This issue can be 14 COMMISSIONER ROBERTS:
What else can this 15 be?
i l
16 MR. SPEIS:
Mr. Roberts, this issue is not t
17 treated as part of as a design basis accident 18 because it is there for -- the requirements that wo 19 imposed on the additions to the plant itself to meet 20 the rule are not the same as the stringent 21 requirements that we apply for design basis i
22 accidents.
And these are described in the Regulatory i
23 Guide itself.
That's what we mean by -- for example, j
24 they don't have to be soismically qualified.
1 25 We think that losing power is more frequent
23 1
from other events than from a seismic event, for 2
example; therefore, if-they add something, it does 3
not have been to be seismically qualified and that's 4
what we mean by that as an example.
5 CHAIRMAN ZECH:
What you're saying is that 6
this rule,is in the category that is considered above 7
the design basis requirements?
8 MR. SPEIS:
Yes, if we look carefully 9
CHAIRMAN ZECH:
It enhances safety beyond 10 the design basis; is that correct?
11 MR. SPEIS:
- Yes, It's like ATWS.
The ATWS 12 category basically.
We looked very carefully at the 13 quality attributes of systems that have to be added.
14 CHAIRMAN ZECH:
I understand that, but it is 15 above 16 MR. SPEIS:
To some extent, yes.
It is 17 somewhere in between.
13 CHAIRMAN ZECH:
Somewhere in between 9 hat?
19 MR. SPEIS:
The design basis and the 20 non-design basis.
l 21 COMMISSIONER BERNTHAL:
It's designed to 22 allow you to cope with the design basis accident or 23 avoid the design --
24 MR. SPEIS:
Avoid --
25 COMMISSIONER BERNTHAL:
well, that's not l
24 1
the cortect terminology either, but 2
MR. SPEIS:
I guess I'll need the help from 3
the lawyers when it comes to defining 4
COMllISSIONER BERNTHAL:
It's a preventive 5
measure.
6 MR. SPEIS:
It is a preventive measure. yes, 7
but it goes beyond the regulations to some extent.
8 CHAIRMAN ZECH:
That's what I'm trying to 9
clarify.
10 MR. SPEIS:
Yes.
Yes.
Our regulations deal 11 with reliability, you know, there is GDC-17, general 12 design criteria 17, that talks about -- we have to 13 have a power source, it has to be reliable and so on 14 and so forth.
It does not address coping and we find 15 from experience, from the extensive experience that I 16 mentioned earlier, that we e t.1 further reduce the 17 risk from this issue by being able to cope with 18 station blackout.
Somewhat, it is beyond the design 19 basis.
Maybe Vic can 20 MR. STELLO:
Clearly this is an issue which 21 we believe merits adding the additional safety we get 1
22 by doing this.
It is safety beyond that now 23 contained in our regulations which set the design 24 basis for the plants.
25 CHAIRMAN ZECH:
Right.
That's what I wanted i
l 25 t
1 to clarify.
2 MR. STELLO:
This clearly goes beyond the 3
design basis as set forth.
4 CHAIRMAN ZECH:
Yes.
That's what I wanted 5
to clarify.
Thank you.
Let's proceed.
6 COMMISSIONER BERNTHAL:
Let me ask another 7
statistical nit here that's bothering me.
How did we j
8 get to 1500 reactor years ~in this country?
We 9
haven't had an average of 50 plants per 30 years, and 10 we're only getting 100 year right now.
Are we t
11 counting subs or something?
12 MR. STELLO:
Do you have the number, Pat?
i 13 MR. BARANOWSKY:
I guess I didn't hear the i
i 14 question.
15 MR. STELLO:
What's the total reactor years j
16 of operating experience for U.S.
reactors?
Do you 1"
have that?
18 MR. BARANOWSKY:
It's over 100C.
I don't 19 think it's 1500.
I don't know what it is right at i
20 this minute.
21 COMMISSIONEk SERNTHAL:
It is over 1000?
22 MR. B A R A !!O W S K Y :
Yes.
23 COMMISSIONER BERNTHAL:
Okay.
24 MR. STELLO:
If you'd like, we'll give 25 you
26 1
COMMISSIONER BERNTHAL:
It's not the sum.
2 That's a small point.
It can't be 1500, though.
3 CHAIRMAN ZECH:
I'm well aware that it's 4
over 1000.
I've got it in one of my statistics books 5
that I keep.
I don't recall the exact number either, 6
but I k'now it's over 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> of commercial nuclear 7
power operations'-- years of nuclear power operation 8
in our country.
9 COMMISSIONER BERNTHAL:
I guess I can 10 believe 1000; I can't believe 1500.
11 MR. SPEIS:
Next viewgraph, please.
12 (Slide) 13 MR. SPEIS:
We have listed here some of the 14 additional benefits of the alternate AC power.
We 15 say it provides a means to cope uith the reactor 16 coolant seal failure which therefore this additional 17 power source or this alternate AC power source can 18 be used to power independent pump seal cooling 19 systems.
20 At present, we have made the assumption that 21 as part of the resolution of A-44 that the seal does 22 not fail, but there is a degradation of some sort, 23 and the maximum leakage is 25 GPM.
And based on 24 that, there is no problem.
25 So the assumption that is made then is that
27 l
1 the seal is not going to fail.
But we have a f
2 separate issue dealing with the, seal issue, and if 3
from that issue we find out that the seal indeed 4
fails, given a station blackout, then that leakage 5
could go anywhere from 60 to 400 or so GPM.
In that i
6 case, they'll have to prove that their seals plant
[
7 specific analysis will have to be done to show.that 8
the seal does not leak or some independent system has 9
to be provided to be able to cool the seal itself and i
i 10 that's why we are'saying there is'a benefit by going i
11 with the alternate AC sources at this point this 12 time.
It will take care of the seal issue so that we i
c 13 won't have to argue with that issue later on.
14 Also it simplifies operator actions needed 15 to cope with station blackout.
Basically you go 16 directly into the alternate source so you don't have 17 to undertake activities that involve the loss of 18 power itself.
19 Also it alleviates environmental concerns 20 associated with station blackout.
For example, 21 overheating of electrical equipment and control room 22 habitability.
23 So we're recommending then that we add to 24 Section 50.63, Section 2, c.2, the thing that is i n-25 the parenthesis there.
If the potential for common
28 1
mode failures can be minimized, use of an alternate 2
AC source is a preferred option since this approach 3
will also benefit other safety concerns.
The next 4
viewgraph slide.
5 (Slide.)
6 MR. SPEIS:
The rule itself again -- its 7
licensed LWR plant must be able to withstand for a 8
specified duration and recover from a station 9
blackout.
Item 2, which is very crucial which goes 10 into the graded approach that I mentioned earlier, 11 Mr. Chairman, where the duration itself will be based 12 on plant specific characteristics as well as location 13 of the plant itself.
14 These are the four important factors that 15 the duration will be based on, the redundancy of the 16 on-site emergency AC power resources it's how many 17 you have and how many you need -- the reliability of 18 on-site AC power sources, the expected frequency of 19 the loss of off-site power, and the other one is the 20 probable time to restore off-site power.
21 The use of alternate AC power sources is an 1
22 option, we mentioned that already.
And of course the 23 Reg Guide provides the guidance for complying with 24 the rule itself.
25 This brings my presentation to an end, and
-29
+
r 1
Mr. Thadani now can continue from NRR to discuss the 2
implementation and the review priorities.
3 MR. THADANI:
Good morning.
l 4
CHAIRMAN ZECH:
Good morning.
Please l
5 proceed.
6 MR. THADANI:
Thank you.
If the station l
7 blackout grew, as is structured now it would require 8
the licensee to make an information submittal in 9
about nine months following the issuance of the rule.
10 (Slide.)
11 MR. THADANI:
The content of the submittals 12 would be expected to include the duration of that 13 plant as well as justification of that category; t
14 proposed modifications, if any, to meet the 15 requirements of the rule, and the schedule for l
l 16 implementation of the modifications.
17 We expect submittals covering over 100 18 plants, so it's clear that it's important that we 19 prioritize our activities and focus on those plants 20 which deserve early attention.
21 And our basis for looking at plants would be 22 relative safety significance.
The top priority will 23 be given to plants which, we believe, were most 24 susceptible to station blackout events, i
25 We have information from Office of Research
30 1
which has identified we believe approximately 17 2
units which belong in this category, and we would pay 3
early attention to those units.
4 We would also screen early on the licensoe 5
submittals to identify, determine if there are other 6
plant units that need early attention.
7 We'd use other other factors in assigning 8
priorities as Mr. Stello and Dr. Speis have mentioned 9
that if proposals come in with alternate AC power 10 source, we expect to assign higher priorities for two 11 reasons:
!! umber one, not only would that approach 12 resolve the station blackout issue, but it would also 13 likely resolve some of the other issues in some of 14 the operating reactors.
15 So we would assign high priority for that 16 reason, plus our review, I expect, would be minimal i
17 in those cases.
18 For the remaining plants we will include 19 consideration of residual risk.
For example, we 20 would expect to pay higher attention to plants with 21 Mark-1 and ice condenser containments over plants 22 which have large dry containments.
23 Our focus is going to be what's most 24 important in terms of again in safety we can 25 achieve.
Let's work on those plants first and go on
= _ _.
31 1
down.
2 Mr. Rosa is going to discuss what we're r
3 going to review, the content of our review as well as 4
the' schedules to these reviews, and I think it would j
5 become a little clear to you why it is important for 6
us to prioritize our activities.
And those are the j
7 kinds of thoughts we'd utilize in prioritizing.our i
8 activities.
i 9
CHAIRMAN ZECH:
All right.
10 COMMISSIONER BERNTHAL:
Let's see.
The 4
11 NUREG 1150 results -- just refresh my memory here 1
12 did show a station blackout to be the dominant risk 13 for the ice condensers 14 MR. STELLO:
BWR.
l 15 COMMISSIONER BERNTHAL:
and the Mark-l's.
l 16 MR. STELLO:
No, the Grand Gulf and the i
17 Peach Bottom, I think we were in the 90s.
One was 95
)
I j
18 and the other 80 something.
j 19 COMMISSIONER BERNTHAL:
And the ice j
20 condensers'as well?
ij j
21 MR. STELLO:
I don't remember.
I i
22 MR. THADANI:
The ice condenser was very i
1 23 significant.
1 I
24 COMMISSIONER BERNTHAL:
That's what I i
25 thought.
I i
_..____,__,..__-,,.1
32 1
MR. STELLO:
That's the ignitor problem.
2 COMMISSIONER CARR:
I have a little trouble 3
trying to figure out why you would put a high 4
priority on the ones who have alternative AC source 5
proposals since it looks like they would be solving 6
the problem and you could leave them until later and 7
go to the guys who might not have the problem solved.
8 MR. THADANI:
In fact, those licensees who 9
proposed alternate AC power source, we'd like to take 10 a quick look and make sure we're satisfied with the 11 proposal so they can go ahead and implement and make 12 the necessary improvements early on.
13 So that's really the motivation:
Not to 14 hold it back, not to delay implementation.
15 COMMIGSIONER CARR:
Okay.
la CHAIRMAN ZECH:
All right.
17 MR. THADANI:
Okay.
Mr. Rosa will 18 discuss 19 CHAIRMAN ZECH:
Thank you very much.
You 20 may proceed.
21 MR. ROSA:
Next slide, please.
22 (Slide.)
23 MR. ROSA:
The Regulatory Guide 1.155 24 describes the means acceptable to the Staff for 25 achieving conformance with the rule.
And the Staff
33 1
review will simply ascertain that by review of the 2
applicants' submittals, that the guidelines of the 3
Reg Guide have been implemented and thereby achieving 4
the attainment of requirements of the rules.
5 The review will focus on those aspects of 6
the requirements that are deemed most important for 7
verifying conformance with the rule, and the first is 8
the determination of the proposed minimum acceptable 9
station blackout duration.
The review will make sure 10 that the characteristics of the off-site and on-site 11 power systems and diesel generator reliability have 12 been adequately considered in arriving at the minimum 13 acceptable station blackout duration.
14 The next important element in assessing 15 conformance with the rule is the station blackout 16 coping capability that will be described in the 17 submittalt.
We expect that those plants that elect 18 to provide coping capability analyses will do so in 19 some detail and the review will verify that we are in 20 agreement with the assumptions and the results of the 21 analyses.
22 COMMISSIONER BERNTHAL:
Are you going to 23 make a suggestion as to what you think would be a 24 minimum acceptable coping time under any 25 circumstance?
I mean let's just say good engineering
34 1
judgment or common sense.
Would the' number be four 2
hours or two hours or one hour or what would it be?
3 MR. ROSA:
Well, the guidance has a category 4
of two hours for those plants that are most capable 5
of sustaining a station blackout.
They're least 6
susceptible to a station blackout.
I would expect 7
that that would be a minimum.
8 MR. STELLO:
I' don't understand that, but 9
let me clarify now before we get too far.
I thought 10 that if someone met all the requirements for 11 alternate AC they did not have to show any coping 12 capability, it was not required.
13 The answer is zero if you add additional 14 power supply that eliminates the blackout as a 15 consideration that you need not show any coping 16 capability; am I wrong?
17 MR. ROSA:
No, you're not wrong.
An 18 alternate AC source that can be started within an 19 hour2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> is acceptable, but coping capability has to be 20 demonstrated for that one hour.
21 If the alternate AC source provided can be 22 started and brought into play from a shutdown in ten 23 minutes, then no coping analysis is required.
That's 24 what the guidance states.
25 COMMISSIONER BERNTHAL:
I guess the thing
1 35 1
that bothers me a little bit about that philosophy is l
well, let me ask a question.
Have you looked f
2 that 4
3 at the comparison of what the world standard i s these 4
days -- compared this with the world standard to i
1 5
determine whether in fact you then will be going i
6 beyond the world standard in terms of alternate i
j 7
capability?
Because I'm using world standard j
8 generically.
The French, for example, I believe, 4
4 9
require something like 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of coping capability.
10 The Germans I believe require something like eight 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> if I remember correctly.
I'm not certain about i
12 these numbers any more.
l l
13 But generally the Europeans have required, 3
14 all other things aside, I believe, a fairly extended 15 period for coping, quote unquote, but I don't know, r
I l
16 quite frankly, whether the kind of analysis that you 1
i 1 */
are proposing, redundancy really, whether that sort I
13 of comparison has been carried out.
Maybe you could 3
I 19 comment on that, j
20 In other words, have they not paid the 21 attention that you intend to pay to the redundancy in j
i 22 a plant with alternate sources?
)
j 23 MR. ROSA:
I believe that considering the 24 differences in off-site power reliability and j
25 frequency of loss of off-site power that exists
,m
~
,--------,.-m.
gnwe
36 1
between, let's say, the Europeans and ourselves, that 2
rule is adequate for meeting the U.S.
requirements in 3
regard to station blackout.
4 Now the French, I believe, in their Palo S
Alto reactor do provide coping capability in the 6
order of 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />.
7 MR. SPEIS:
I will like to say something 8
because basically the French approach is not 9
different from our approach.
They have provided 10 cooling, direct cooling to the seals.
11 They have found from their analysis that the 12 Achilles heel is the coping domain, okay, and 13 therefore they provide an independent power source 14 and that is our recommendation, too.
15 To compare coping times, whether they are 15 16 or 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, you know, these are not very easily done.
i 17 For example, if you don't consider equipment 18 qualification or if you lose power for ten hours, 19 somebody has to make sure that the equipment is 20 operable that are needed for the duration of the 21 coping, and I don't think those analyses.have been 22 done to really prove that one can cope for eight i
23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> or 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.
24 Therefore, in fact, that is the reason, even 25 though they say that, that is the reason in their
)
,y
____.-y,._#-
, -...--.,...-,-,. ~_,,
,w..
37 I
1 last analysis they go and put an independent power 2
source to cool the seals.
So in that regard, yc 3
know, our proposal is not different than theirs.
4 CHAIRMAN ZECH:
We have a comment from 5
MR. RUBIN:
Yes, I'd like to amplify a 6
little bit.
My name is Alan Rubin, task manager of 7
the U.S.
Site 44.
Having visited the Palo Alto site 8
and reviewed the French experience, there is some 9
other reasons why the French and other countries have 10 gone beyond what we are proposing in this resolution.
11 One important part is the stability of the 12 grid and the frequency of initiating events of losses 13 of off-site power.
14 I believe the French have about a factor of 15 two higher frequencies of total losses of off-site 16 power than we have here, and that's a direct factor 17 in terms of the frequencies of core damage.
18 COMMISSIONER BERNTHAL:
A factor of two, 19 yes, that's not a terribly impressive difference.
20 What about Germany where I think it's'eight hours?
21 Isn't it six or eight hours?
22 MR. RUDIN:
I haven't seen the data for the 23 frequencies for German losses of off-site power, but 24 in Sweden I know they have had some large losses 25 which have affected a significant portion of the
____ _ _f
38 a
i i
country, I'd say about half the country and they got i
2 particularly concerned because of the north-south
'I 3
transmission lines in that country and they have 4
additional redundancy in terms of diesels and gas-i l
5 turbines at that site because of the transmission 6
t l
i 6
line situation.
7 COMMISSIONER BERNTHAL:
And you don't know 8
about Germany.
9 MR. RUBIN:
I don't know about the 10 frequencies of losses, but I know they have a
11 additional capability in terms of redundancy, i
12 diversity in power supplies.
t 13 MR. SPEIS:
The Germans rely on diesels 14 basically.
They don't have any extra cooling of the 15 seals.
They don't think it's a concern because of
[
16 the large number of diesels they have basically.
t 17 The English for their size, well, they rely 3
18 on seal cooling just similar to our proposal, and the 1
19 French, so I think in general, you know, we're not 20 inconsistent with --
4 21 COMMISSIONER BERNTHAL:
Well, the reason I i
1 22 make a point of it 4
and we should go on here, but 4
23 that's the first question that you and this 24 Commission is going to be asked, it seems to me, J
25 because whether we're playing on the same level field i
1 39 I
}
o l
and it sounds like what you're saying is 1
or not l
l 2
that we're not -- at least the word that's around is 3
the French have 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> and the Germans have eight j
4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the Swedes, I don't know how many hours j
S they have, I don't know what the Japanese have better be 6
either, and it just seems to me that we i
7 prepared to explain why what we are doing is the 8
functional equivalant of that.
I think that's what 9
you're telling us.
]
10 MR. SPEIS:
I think, yes.
And we have 11 looked very carefully at what the grid is, what the i
12 Germans and what the Swedes and what the French have i
13 done, and I think we're satisfied that we are, if I 14 use your words, functional equivalent.
15 COMMISSIONER BERNTHAL:
Okay.
Just so that 16 we've got that nailed down --
17 MR. SPEIS:
Yes.
18 COMMISSIONER BERNTHAL:
-- because I think 19 it's important.
20 MR. MINNERS:
A small clarification.
We 21 were just talking about two hour coping capability.
22 I think most plants will probably have a four hour 23 capability because the industry has indicated that
)
24 they will make a commitment to make changes to the 25 design and put everybody in a four hour category.
40 1
The rule allows or requires some plants 2
or allows some plants to have a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping 3
capability depending on those if they are unusuni 4
plants.
We don't expect to find many or any of 5
those, but there's a possibility that some plant 6
would have to have a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> capability.
7 CHAIRMAN ZECH:
All right.
Can we proceed?
8 MR. ROSA:
The next area of concentrated 9
review effort will deal with the modifications, 10 potential modifications that would be proposed in ICT 11 submittals.
j 12 These areas include alternate AC source 13 additions, reactor coolant pump seal failures, 14 features to prevent reactor coolant pump seal 15 failur battery capacity, addition of or adequacy of 16 existing batteries, condensate storage capacity.
l 17 Now the review will attempt to ascertain t
18 that any modification may in fact do -- provide the 19 intended enhancement in coping capabilities and it i
I 20 will also verify that whatever modifications are i
21 made, do not adversely impact existing safety related 22 systems.
23 An additional element of the review will 24 address what procedures in training are being 25 provided for station blackout,
41 j
l 1
It is expected-that regional audits may be l
W 2
performed to look at the procedures that are in place i
3 and the training that is being conducted.
4 Finally, the question of operability I
i l
5 requirements for station blackout equipment, how a
l 6
these are defined and implemented.
i 7
The question of possible imposition of 8
technical specifications has been discussed.
These f
9 requirements could also be contained in f
i 10 administrative procedures.
{
j 1
\\
11 If technical specifications are decided on, l
12 I believe they will be minimal in addressing perhaps i
13 at best the alternate AC source operability
[
l I
1 14 requirements.
l 15 In any event, whatever is decided on in J
16 regard to technical specifications will conform to 17 the commission's interim policy statement on i
18 technical specifications.
Next slide, please.
]
19
[ Slide.)
j 20 MR. ROSA:
The schedule shown on this slide j
21 assumes that the station blackout rule will be issued 1
22 on June 1st of this year.
It takes into account the 1
23 270 days allowed for industry response, and it i
I 24 assigns what we consider to be a reasonable 25 allocation of Staff resources to this task given the
42 1
other workload that has to be performed and the 2
amount of technical assistance funding that is made i
3 available for this task.
l 4
The rule states that 30 days after the l
5 notification to a licensee that their proposed fix 6
for the station blackout issue is acceptable, that 7
they should provide a firm schedule for 8
implementation which should not exceed two years 9
unless some very firm justification for extending 10 that beyond two years is provided.
l 11 So the completion dates or implementation l
t 12 dates shown on there fall two years and one month
[
13 following the Staff evaluation completion for the 14 particular sites.
l 15 The reviews ~have been based on site reviews
[
16 rather than unit reviews because in a site review, a I
17 unit -- a two unit site with essentially similar 18 plants would not require two reviews.
So it's shown 19 there in terms of site reviews.
20 The first 24 highest priority sites, the 21 review would be completed by !!ovember the 1st of '89; 22 the next 35 sites evaluation would be completed by 23 October 1st of '90; and the final 16 remaining sites 1
\\
24 evaluation will be completed on March 1st of
'91.
I 25 If things go according to plan, all sites
~-.
43 1
i l
1 should have implemented the station blackout rule by i
2 March 31st of
'93.
I l
J I might say one other thing about the review i
l 4
process.
We have interacted with the utility' working l
4 5
group that produced NUMARC 8700, their initiatives j
6 document, and have obtained an agreement in most t
7 areas.
]
8 We believe that this will result in a
- 1 9
standardized licensee submittal in both format and i
10 content which will ease the task of the Staff in i
l 11 reviewing it.
1 i
i k
12 I think that's a plus for both the 13 regulatory process and the industry.
14 CHAIRMAN ZECH:
All right.
i 15 MR. STELLO:
We're through, Mr. Chairman.
I 16 CHAIRMAN ZECH:
All right.
Thank you very J
l 17 much.
Questions, my fellow Commissioners?
i i
18 Commissioner Roberts?
19 COMMISSIONER ROBERTS:
March the 8th, we I
20 sent you a bunch of questions and you responded.
I i
1 21 think I read it last night.
Response to Question 4:
i i
22 "Plants with very short required coping times may be i
j 23 able to disband seal failure without core recovery."
1 l
24 Qualify that.
What is short?
l 25 MR. SPEIS:
Several hours, Mr. Roberts.
l
44 1
COM!!ISSIONER ROBERTS:
Several hours?
2 MR. SPEIS:
Yes.
A few hours, less than 3
four.
4 CHAIRMAN ZECH:
Do you want to come to the 5
microphone, please.
Identify yourself for the 6
reporter.
7 MR. BAER:
Yes, I'm Robert Baer.
It's a 8
complicated issue.
If all the seals 9
CHAIRMAN ZECH:
Identify your --
10 MR. BAER:
Oh, I'm Chief of the engineering 11 and issues branch in Research.
12 CHAIRMAli ZECH:
Thank you very much.
13 MR. BAER:
This generic issue 23 is assioned 14 to my branch.
If all the seals if the seals fail 15 completely on a given pump, leakage could be as great 16 as 480 GPM.
17 And with four pumps, it could withstand only 18 about an hour or so before the core is uncovered.
If 19 there was no other you know, if you don't cool the 20 seals.
21 So it could be for plants under an hour, you 22 could probably expect complete seal failure.
But for 23 tonger duration coping times, the seals have to hold 24 at least to some degree.
25 CHAIRMAN ZECH:
All right.
Thank you.
45 i
I 1
Anything else, Commissioner Roberts?
l 2
COMMISSIONER = ROBERTS:
No.
l 3
CHAIRMAN ZECH:
Commissioner Carr?
4 COMMISSIONER CARR: No.
5 CHAIRMAN ZECH:
Commissioner Rogers?
l 6
COMMISSIONER ROGERS:
Well, yes.
This
+
t 7
timetable, the 3-31-93, full implementation dt.te, is l
8 that set by the availability of NRC Staff resources l
9 to review licensee proposals?
f 10 MR. ROSA:
I would say that to some extent 11 it is.
We have considerable other workload.
Events 12 are occurring day by day that require Staff effort in-13 reviewing and resolving, and we have devoted what we 14 consider to be a reasonable amount of Staff resources l
15 for this task.
j 16 COMMISSIONER ROGERS:
Well, suppose a 17 licensee wants to go faster and get this thing out of 18 the way and behind them, are they limited by_your 19 identification of the highest priority sites?
20 Suppose somebody, in your opinion, has a low 21 priority site, wants to get it behind them and get it 22 off their books by moving more rapidly, will they be 23 prevented from doing so because of the Staff 24 limitations?
25 HR, STELLO:
No.
We encourage it.
And if
46 1
all of them want to do that, we'll find a way to get 2
them done.
3 COMMISSIONER ROGERS:
All right.
And it 4
seems to me that that's a rather long time to wait to 5
get this issue totally bundled up and put to bed, and 6
I would think, anyway, if we could move more rapidly, 7
it would be very desirable and I would hope that the 8
limitation just isn't simply our own Staff's 9
resources and inability to review proposals.
2n MR. STELLO:
Let me say what I have said a 11 number of times in the past, that I think the 7
industry ought to seize on this particular issue as 12 13 an opportunity to solve not only the station blackout 14 issue, but if they go about doing this carefully, 15 they can integrate and solve a number of other issues 16 that the pump seal being one, decay heat removal 17 being another issue.
There are other issues that are 18 out there and I think they could go a long way in 19 getting rid of when they look at the plant from their
)
20 own perspective, so I'd hope that the schedule allows 21 sufficient time for them to be able to take a pretty 22 good look at being able to integrate a whole base of 23 solutions into the plant.
24 COMMISSIONER ROGERS:
Well, I'd just like to 25 say that I really didn't have as much time as I would
47 1
like to really study the report, but everything I've 2
seen of it seems to indicate that it's an un usually 3
capable and fine piece of work, and tough issue, 4
thorny issue, and the detail and thoroughness with 5
which the Staff approached this problem, I felt to be 6
very impressive.
To try to get your arms around it 7
and get it in some kind of a shape for dealing with 8
what I thought was really an impressive piece of 9
work.
10 I want to compliment you on it, everyone who 11 participated in it.
12 COMMISSIONER CARR:
Can I follow up on that 13 a little bit?
Does the utility have to get our 1
14 permission to add on-site power sources?
I don't see 15 any reason they should.
They ' night have to get our 16 permission to hook it into our system. but I m,uld
)
17 think they can go all out and if they want to put in 18 a gas generator or something, they could put it on 19 site certainly without us telling them they couldn't.
20 MR. STELLO:
But the application of bringing 21 that onto the site to dealing with the compliance of 22 this rule 23 COMMISSIONER CARR:
Well, as I say, for that 24 they may have to have our permission to hook it up.
25 They could go a long ways to getting the problem
-48 I
solved before 1993, I'd think.
2 MR, STELLO:
They could do that now.
3 COMMISSIONER CARR:
Okay.
4 COMMISSIONER BERNTHAL:
Yes, I share the 5
concern, though, that Commissioner Rogers raises.
It 6
is an awfully long timetable and we've had one or two 7
cases of plants that were waiting for start up where 8
they have taken fairly rapid steps on their own, 9
bring in gas turbines or whatever it might be, 10 You know, you guys -- we have to worry about 11 hooking it up, as Commissioner Carr'says, but I would 12 hope that we don't get distracted by global solutions 13 here when we have one rather important item that as 14 you point out and as that page shovs represents 90 15 percent, 90 odd percent in -- well, one assume in 16 many of the boilers.
17 So that by taking care of that single item,
{
18 in effect I guess you dropped core melt probability a I
19 factor of ten.
I think that's pletty important.
We 20 ought to get at it, l
21 MR. THADANI:
Yes.
In fact, if I may just 22 make a comment, if the utilities were to come and 23 propose some alternate AC power souret. I's firmly 24 convinced that our review process is minimal in that 25 regard, and it gets down to the point of hooki M; it
)
i i
49 i
i
{
L i
up, essentially.
And if that were the proposal, then I
l 2
I don't expect the Staff would need to do much of a J
t 1
3 review and therefere the schedule would in fact be I
l 4
inappropriate as you see it.
i 5
The schedule is developed on the basis of a 6
substantial amount of analyses and reviews and back j
7 and forth, if you will, but nevertheless-the focus of 8
our review will be to address plants where we believe 9
this issue is very important as early and as quickly 10 as possible, and that's what we mean by dividing it 11 up in terms of number of sites that we have -- we l
12 intend to address early on.
So we are very sensitive f
13 to the point you make, Commissioner Rogers.
i
?
f 14 COMMISSIONER ROGERS:
I will hope that if i
15 this whole thing is approved and goes through and 16 goes into action ~, that we be would be kept informed 17 of how this implementation schedule is actually 18 working in practice and that I would hope to see some 19 modification of it once the process begins, that l
20 maybe some new things would come such as initiatives j
21 from the industry itself, to move more quickly and 22 rapidly to get this thing behind them.
l t
i 23 I would think that everybody would like to l
24 see this thing cleaned up and out of the way because 15 it's been hanging around for so long and it looks as
50 L
if you've got all the elements here to move fairly 2
quickly and rapidly to clean it up.
3 HR. STELLO:
We'll do our best to improve 4
the schedule and we will keep the Commission informed 5
if it goes forward with the rule on progress.
6 CHAIRMAN ZECH:
All right.
Commissioner 7
Bernthal?
i 8
COMMISSIONER BERNTHAL:
Yes, I had a couple i
9 of other things I wanted to ask ab;ut, and then a 10 suggestion.
11 I'm not sure I quite understood.
If we can 12 go back to one of your slides here, I guess it's No.
13 5.
I'm not sure.
You have this additional 14 recommendation which has, I believe, appeared between 15 the time you sent the package and now.
16 If I missed the point when you explained it 17 then you'll have to re-axplain it, but I didn't quite 18 understand why you have reached a technical judgment 19 that an alternate AC source is to be preferred over 20 whatever the other options might be.
Why is that?
21 MR. SPEIS:
Well,, we reached the point, I 22 guess, in the last few months or maybe few wewks that 23 we looked at the resolution of the seal issue, and if 24 we are not able to ascertain the integrity of the 35 seal, then it's possible that one of the requirements
51 1
will be to put a power source to provide cooling to 2
the seal itself.
So we are bringing this to the 3
attention -- we are bringing this right now on this 4
issue because it's an integral part of this issue.
5 Independent power sources provide it, it results for 6
the cooling of the seal, the reactor coolant pump 7
seal at the same time, so --
1 COMMISSIONER BERNTHAL:
I'm not sure I --
9 you're going to have to do a little more better.
I'm 10 not sure I follow you.
11 MR. STELLO:
Let me give you a few more 12 reasons.
Look at the 80 percent core melt 13 frequency 90 percent core melt frequency.
Those 14 plants will probably meet this rr'e without doing 15 anything.
Okay?
16 COMMISSIONER BERNTHAL:
Yes.
17 MR. STELLO:
So you are going to wind up 18 with still dominating.
If you add an alternate power 19 source, you're going to get a factor ten reduction in 20 those plants.
21 Remember, they have been re-analyzing in the 22 10 to the minus 6 range now.
23 COMMISSIONER BERNTHAL:
Yes.
24 MR. STELLO:
Excuse me, down two.
- Second, 25 there are the a lot of the intangibles that you 9
52 1
get as indirect benefits of having that' alternate 2
source especially if it's diverse.
You don't have 3
to worry about any common mode failures, 4
contamination of fuel supplies, common mode failures 5
due to maintenance or whatever, especially with the 6
diversification.
7 In addition, events in the plant such as 8
floods, fires, the kinds of things that again become 9
intangible that can affect a lot more equipment.
10 You add substance dimention to the 11 defense in depth that you have in the plant by having 12 the diverse alternate power source.
13 We aren't saying you're required to do, but 14 everything we know suggests that you have through it i
15 the mechanism to solve a whole host of other i
16 technical issues and further substantially improve 17 the safety of the plant.
18 COMMISSIONER BERNTHAL:
Okay.
- What,
- f. o r 19 example, qualifies, just for my information, as an 20 alternate AC source?
Does that mean, for example, 21 that you bring in a gas turbine or --
22 MR. STELLO:
A gas turbine, another diesel j
23 generator.
l 24 COMMISSIONER BERNTHAL:
Okay.
l i
25 COMMISSIONER CARR:
Let me ask you if I l
53 1
understood what you said.
It sounds to me like what 2
you're saying is that they may qualify adding 3
additional power source under the blackout rule, but 4
when we solve the pump seal problem we may require it 5
anyway.
6 MR. STELLO:
And that's why I said I hope to 7
make the statement that when the i'ndustry goes out 8
and they look at all the other things that are out 9
there on the horizon as they understand it, things 10 they'd like to do with this plant.
11 This may be a desirable thing for them to 12 do.
They wouldn't have to deal with the coping 13 analysis at all if they did have an alternate source.
14 COMMISSIONER BERNTHAL:
Okay.
I want to get 15 back just a little bit to the minimum, c.lthough I 16 guess the minimum is zero hours of coping capability.
17 You've been giving an explanation of why we 18 in the public should be willing to accept what on the 19 surface at least appears to be a different -- appears 20 to be a lesser standard for coping capability than --
l 21 it seems to be the mode now in Europe these days, and 22 I would just suggest that there needs to be put 23 together fairly coherent understandable comparison 24 and explanation of your arguments for why we are the 25 functional equivalent, if you will, if indeed we are,
54 1
to the requirements that Europe is placing on its 2
plants,'and included in that kind of argument and 3
justification it seems to me should be the 4
consideration of the differences of off-site power 5
reliability, for example, as you've mentioned, but 6
also included in it should be the fact that weather 7
conditions in this country, particularly in the 8
winter, very often can be much more severe than in 9
France and Germany, for example.
You don't believe 10 that?
11
~
MR. STELLO:
Down in the Alps?
12 COMMISSIONER BERNTHAL:
Oh, come on, Vic.
13 Most of France and Germany is not the Alps.
I 14 MR. STELLO:
But you've a lot of 15 interconnecting grid systems that go over the 16 mountains and there are problems.
17 COMMISSIONER CARR:
I remember last winter 18 when they froze up the river, they lost quite a few 19 of their nuclear plants because the intakes were 20 frozen.
21 MR. STELLO:
Let me -- I see where you're 22 going and I'm a little bit troubled because I don't 23 know that we even have enough information or if it's 24 wise for us to try to get into studying their 25 off-site power supplies, the weather problems, the
0 55 1
kinds of things that we have generated an awful lot 2
of data and had access to a lot of data in the United 3
States to really be'able to go through that.
4 COMMISSIONER BERNTHAL:
What I'm saying is 5
that it seems to me that one of the principal causes 6
of long-term loss of off-site power, at least in this 7
country, will be weather-related.
You don't have to 8
live in the Midwest very long or the Northeast or the 9
vast land mass of the United States of America to 10 understand that's far more likely in this country 11 than in the more benign climates of Europe.
I nie a n,
12 Europe is simply a more milder climate.
13 MR. MINNERS:
But I don't think the 14 statistics show that.
I'm no expert on this, and 15 correct me if I'm wrong, but I think the French have 16 a higher rate of loss of off-site power --
17 COMMISSIONER BERNTHAL:
But that may be for 18 different reasons.
Is that true?
19 MR. MINNERS:
But I guess the point I'm j
20 trying to make, you have to look at the overall loss.
21 COMMISSIONER BERNTHAL:
No, I agree.
And I 22 agree the reliabilty of the system is on the one 23 hand, but on the other hand are these factors that 24 are more severe in our country.
25 All that I'm saying is that those are the
56 1
questions that are going to be asked and we better be 2
prepared to answer them.
3 MR. STELLO:
Well, I could tell you this.
4 If they're asked anywhere in the foreseeable future, 5
we're not going to be able to answer and in order to 6
answer them, we're going to have to initiate a very, 7
very large program.
8 We do not have the kind of information --
9 you would need to know the stability of the grid 10 systems in each of those countries and that's going 11 to take a great deal of doing.
We don't have that 12 information.
13 COMMISSIONER BERNTHAL:
We have no 14 statistics on lo'ss of off-site?
15 MR. STELLO:
We could go try to get them, 16 but we don't have them readily available, and we 17 don't have very much information on the details of 18 what they've done for their coping analysis.
All we 19 do know is that the French started out that way.
20 When they did, they decided they had to go back and 21 add additional equipment in the plant for the coping i
22 with seals, I don't know what else they did.
I don't i
23 really know that we have a fairly good understanding i
24 of what the Germans did.
We'll have to go back to i
25 them and collect a lot of information.
57 1
We'll do that if the Commission wants us to, 2
but we don't have it now and it will take a 3
substantial effort for us to do it.
4 MR. SPEIS:
I think it is fair to say that 5
the Germans and the-Japanese
---we're not aware that 6
they have done any coping now because they depend on 7
this reliability.
8 You know, the Japanese, they overhaul their 9
diesels and every menth or every six months, 10 whatever, and they want to make sure they operate --
11 I don't think they have done any --
12 COMMISSIONER BERNTHAL:
I thought the 13 Germans had an eight hour coping standard or 14 objective?
15 COMMISSIONER CARR:
I'm not sure all that j
16 data would be of any value other than just a 17 discussion or an argument over who's doing it better 18 than somebody else is.
19 What we are really saying is that we don't i
20 have a problem, we're trying to make them safer in 21 the long run than safe and we are trying to get down 22 another factor of ten, not in the reliability of 23 power at the site, but we're trying to get down 24 another factor of ten in the contribution to a core 25 melt problem.
58 1
And I'm not sure it's worth going out on a 2
major exercise to find out a lot,of data just for 3
argument sake.
4 COMMISSIONER BERNTHAL:
Well, I think it's 5
worth being able to give the public fairly 6
convincing, straightforward, simple answers to the 7
question of why can we permit in principle, at least 8
zero hours when other countries are requiring rather 9
long coping periods and -- I'm not convinced that we 10 don't have the data at hand to make a coherent --
11 COMMISSIONER CARR:
I would think the French 12 citizens would be more on the other side arguing why 13 do they need 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of coping capability when we 14 get by with only six?
15 COMMISSIONER BERNTHAL:
It's all public 16 perception that 17 COMMISSIONER ROGERS:
Mr. Chairman, if I 18 could --
19 MR. STELLO:
Excuse me.
If I may say 20 something.
It's disturbing to me that there's a 21 suggestion that if someone comes in and adds 22 additional power supplies to the on-site system, a 23 diverse turbine generator, that somehow in any way is 24 less desirable or it's degree of goodness, if you 25 will, is somehow less than a plant that maybe has 10
59 1
hours, 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of coping capability.
I'd certainly 2
like never to have a station blackout is the better 3
objective.
4 COMMISSIONER BERNTHAL:
I'm not disagreeing.
5 If you are prepared to say that, that's what I'm 6
saying.
7 MR. STELLO:
That's exactly what we're 8
saying, is our preferred course is go to zero coping 9
capability because you will not have a blackout.
You 10 will need none, zero analysis to show coping because 11 you're not going to have a blackout.
12 COMMISSIONER BERNTHAL:
Look, what I am 13 saying is that I think you have,the data and the 14 arguments in hand to present to the public a coherent 15 explanation, a simple explanation of why we don't 16 have to do that's what you're telling us, we don't 17 have to have coping time because 18 MR. STELLO:
Oh, that we can do because 19 that's internal to us.
20 COMMISSIONER BERNTHAL:
How, you have 21 already mentioned today the lower reliability of the 22 European grid systems I don't know the statistics.
23 I don't know whether that's true, but you've 24 mentioned it and it seems to me that another element 25 of considera^. ion here on the other side of the 4
g e--
~
60 1
argument may well be the severe weather conditions 2
that we're always subject or often subject to_in this 3
country.
4 We do after all deal with tornadoes.
Other 5
countries don't, _for example.
So all that I am 6
saying is better put it together and be prepared to 7
deal with it, and I think it's worth doing that so 8
the public understands.
That's all that I'm trying 9
to say.
10 COMMISSIONER ROGERS:
Well, if you simply 11 present it in such a way that focuses on the 12 advantages of the alternative power source, just what
~
13 that does, that that reduces the time minimum that's 14 required to establish a coping policy, then you can 15 put those other numbers -- tae other countries in 16 some perspective and not have to use them as the 17 starting point for your argument, you know, it's just 18 background, and then you don't really need to do a 19 detailed study because you're not going to base your 20 reason on those data but on an alternate approach.
21 I'd like to just raise a little question 22 about the wording of some of the pieces of paper here 23 because it seems to me that it could be a little 24 confusing in that the proposed resolution is referred 25 to as one which requires that all plants be able to
~- -
61 1
cope with station blackout for a specified duration.
2 That's not what it is.
It's that each plant 3
be able to cope with station blackout for a specified 4
duration.
5 And there isn't a sinole number that applies 6
to all plants, and I see the public notice enclosure, 7
one, uses those same words to require that commercial 8
nuclear plants be capable of withstanding a total 9
loss of AC power for a' specified time.
10 That's not correct.
That's strictly not 11 correct.
It's that each plant has its own time.
And 12 I would suggest that you carefully review the wording 13 that goes out on this so that you're not subject to 14 some criticism of saying one thing and doing 15 something else that's different because it suggests 16 that it's a single number, and there isn't a single 17 number, there's a single approach, but there's not a 18 single number.
19 MR. SPEIS:
Al here brings to my attention 20 in another paragraph it stated the way you're saying 21 it so we'll better make sure it's consistent.
22 COMMISSIONER ROGERS:
Yes.
Right.
23 MR. SPEIS:
Okay.
24 CHAIRMAN ZECH:
Commissioner Bernthal, any 25 other questions?
62 1
COMMISSIONER BERNTHAL:
I had one other 2
peint I wanted to raise and I see there are industry 3
representatives here so perhaps if we are not 4
prepa' red to explain ourselves, the industry would 5
like to explain, though, why what we are ~doing is 6
good enough or is better, perhaps, than what the rest 7
of the world is doing.
8 The last question on the backfit analysis.
9 I have not had a chance to go through that element of 10 your presentation here and it hasn't really been 11 mentioned much here, but since this rulemaking and 12 step here does go beyond adequacy, I take it we will 13 have to base this rule on some sort of backfit 14 analysis, cost benefit analysis, will we not?
15 The last time around on this issue, I 16 thought it was a pretty shaky proposition, and I 17 don't remember exactly what the numbers were.
I 18 think it came down to a factor of two and I'd hate to 19 argue the errors on a number like that.
Are we 20 prepared to provide the arguments we need here or are 21 we going to rely on qualitative arguments?
22 MR. SPEIS:
Well, we have done the 23 arithmetic to the best of our ability.
I think the 24 latest numbers that we came up with was that the 25 value impact ratio showed numbers like two and a half
63 1
thousand person rems per mill _ ion dollars compared to 2
the thousand dollars that we use as a criteria.
And 3
that is of course with no on-site c o s t r..
If you use 4
on-site costs, that number goes to six thousand.
5 Now the thing I said earlier, Dr. Bernthal, 6
that we feel it meets the backfit rule and of course 7
this is in the category of safety improvements and it 8
does have to meet the criteria of the backfit rule.
9 COMMISSIONER BERNTHAL:
What's the cost 10 benefit ratio that you will argue now and what are 11 your uncertainties?
12 MR. SPEIS:
Well, I guess -- we discussed 13 them in the report, I don't remember them, but, you 14 know, that was our best estimate.
That number can be 15 anywhere from 500 to 5,000.
16 COMMISSIONER BERNTHAL:
I think it was a 17 factor of two.
Is it still a factor of two or 18 something like that?
19 MR. RUBIN:
It's in the report.
Alun Rubin 20 again.
I authored the regulatory analysis and on 21 Table 12 of the regulatory analysis there's a summary 22 of the cost benefit ratio.
The best estimate is 23
$2,400 excuse me.
2,400 person rem per million 24 dollars.
The high and low estimates, the high 25 estimate is 5,000 person rem per million dollars, the e
64 1
low estimate is 700 person rem per million dollars.
2 And the details of how those numbers were 3
developed are included in NUREG 1109.
4 MR. SPEIS:
With no on-site costs, right?
5 MR. RUBIN:
That is without on-site costs.
]
6 The number that somebody mentioned earlier of 7
including on-site costs would, double or triple the 8
value of that ratio.
1 9
MR. MINNERS:
It's 6100 with on-site.
10 MR. RUBIN:
With on-site, that's right.
1 l
11 COMMISSIONER BERNTHAL:
Is the Commission 12 going to rely -- I'm asking the General Counsel i
l 13 now -- would the Commission rely on that numerical 14 analysis or would it rely rather on a qualitative 15 argument in this case?
16 MR. PARLER:
Well, I'll answer it.
I think
]
17 the Commission always in matters such as this will 18 rely on the best information that it has.
19 If cost benefit analysis in a situation like 20 this were viewed as not favorable and not 21 comparative -- not, relatively speaking, favorable 22 with something else such as the costs standard, it is 23 my judgment that they could and should rely on both 24 including the qualitative judgment of the Commission 25 that under the circumstances having gotten and
O 65 1
received the best analysis that they could, that 2
either it is a right thing to do or it is not a right 3
thing to'do.
4 If under these circumstances they conclude 5
that it's the right thing to do, I have a very high 6
accomplished level, that if the backfit rule -- if 7
the rule is challenged on the basis that it doesn't 8
comply with the backfit rule that the rule will 9
survive on that challenge.
So it should rely on 10 both.
11 COFMISSIONER BERNTHAL:
Okay.
Thank you.
12 CHAIRMAN ZECH:
All right.
Well, let me I
13 just make a couple of points.
14 (Commissioner Bernthal left the room.)
15 CHAIRMAN ZECH:
Well, first of all, I'm 16 informed regarding reactor years in our country that 17 as of the end February of 1988, the 106 units that we 18 had on line at that time have accumulated 1,076 19 reactor years of operation.
And if you add the 20 reactor years of operation of those plants that had 21 been operating but are not permanently or 22 indefinitely shutdown down, that's 94 more reactor 23 years, so a total at the end of February cumulative 24 in our country would be 1,170 reactor years of 25 operation.
That's just for the record.
66 1
Well, first of all, let me j".st say this.
2 We are discussing a very, very important issue that's 3
been before the Agency for a long time as we 4
emphasized earlier this morning.
I think the Staff 5
frankly has done a very fine job in their analysis 6
both by the research people and the NRR people and 7
those who have supported them.
8 We're talking really about, as I understand 9
it, beyond adequacy.
It's an increasing enhancing 10 safety really beyond a design basis which is I think 11 very appropriate.
You've told us that it does meet 12 the backfit analysis.
13 (Commissioner Bernthal returned to the 14 room.]
15 CHAIRMAN ZECH:
I do think regarding 16 Commissioner Bernthal's reference'to other countries 17 that it is worth looking into.
I would think you'd 18 perhaps have the information available and if you 19 don't have, I would suggest that we could probably 20 get sufficient information from our association with 21 the European countries and I would suggest that you 22 do that.
23 I think it is worth at least being as 24 complete as we can to address that particular subject 25 recognizing there are differences in the approaches
67 1
and so forth.
It seems to me that's worth doing.
2 The alternate source approach -- I guess my 3
question would be on that, why have you concluded 4
that it would be acceptable for a utility to accept 5
an alternate source, for example, an extra diesel 6
generator' or gas turbine and not perform a c.oping 7
analysis so in ord'r to demonstrate that there would e
.8 be a high probability of handling a station blackout 9
in a reasonable period of time?
10 Why have you -- as I understand it, that's 11 what you've suggested.
I'd just like to know the 12 rationale for that.
13 MR. SERKIZ:
Mr. Chairman, the reason -- the l
14 way --
15 CHAIRMAN ZECH:
Maybe somebody ought to 16 MR. STELLO:
Warren.
l 17 CHAIRMAN ZECH:
We appreciate you're trying, 18 anyway.
Maybe you could colleague and write him a 19 note and he can try to explain it for you.
20 MR. MINNERS:
Well, I think the basis of it 21 is that the alternate AC source is going to be 22 connected up -- be able to be connected up to the 23 normal electrical distribution system.
So you're not 24 doing anything unusual and we are going to I guess 25 maybe iu lieu of a coping analysis, we will also
68 1
require licensees to perform a test.
So once'the 2
equipment is installed, they are going to have to 3
show that you can connect it all up and start it up 4
and operate the equipment.
So we are really having 5
an on-site test pretty much in lieu of a coping 6
analysis.
7 CHAIRMAN ZECH:
All right.
Go ahead.
8 MR. STELLO:
Let me try adding a dimension 9
to that.
And if I remember right, a diesel 10 generator, gas turbine, you can get 9.99 reliability 11 and you'd have a potential-there for a station 12 blackout, whatever the number is, X,
so you can add 13 this independent power source.
The potential of ever 1
14 having that problem can then be reduced by one to two 15 orders of magnitude.
16 Such you'd never have, you reduce it to a 17 residual risk so low as the likelihood of ever having 18 a station blackout that you don't need to do 19 anything.
20 On the other hand, if you don't have that 21 power source and you are dealing with just the 22 overall probability of happening of X, then you need 23 to add a dimension called coping or another way to 24 say it is it allows you to be to deal with a station 25 blackout for a length of time to provide you with the
69 1
time it takes to either have the off-site power 2
restored or perhaps to repair or modify whatever you 3
need to do to one of the diesels and get them 4
started.
5 And typically the numbers, if r,omeone would 6
help me, if you can extend the loss or cope with a 7
loss of off-site power for X hours, what's X, you can 8
get about a factor of three or four improvement in 9
having it restored.
10 What's the likelihood?
Does nobody remember 11 the number?
12 MR. BARANOWSKY:
Typically if you went from 13 say two to four hours, you get about a factor'of 14 three; in four to eight, about a factor of three 15 reduction.
Roughly, it varies.
16 MR. STELLO:
That's the likelihood of having 17 an off-site power restored.
18 CHAIRMAN ZECH:
All right.
i 19 MR. STELLO:
So it clearly is desirable to 20 have that source on-site.
21 CHAIRMAll ZECH:
All right.
Commissioner 4
22 Rogers, I think you 23 COMMISSIONER ROGERS:
Well, yes, on that, I 24 wonder if you could tell me how it would work if a 25 licensee installed, let's say, a diesel generator or
70 1
gas turbine or something of that sort, for emergency 2
power, without doing a coping analysis and then for 3
some reason after some period of time while this 4
thing has been in place and sitting there and some 5
routine test is performed on it, it's found that it 6
has to be torn down and something has got'to be 7
fixed.
8 What condition does that put the plant in 9
then?
Is that a condition for shutting the plant 10 down?
Is it a condition for -- is it a condition 11 what status is it in until that correction is made, 12 particularly in the absence of a coping analysis?
If 13 there were a coping analysis that said well, you 14 know, this plant is okay for eight hours or something 15 of that sort and that's all the length of time it 16 would take them to fix that alternative power source, 17 then they're all right.
But if it exceeds that, then 18 what kind of a situation would they be in?
l 19 And if it wasn't a coping analysis, aren't 20 they operating in a kind of a never never land under 21 a circumstance such as that?
22 MR. STELLO:
Well, if they put the alternate 23 source of power on, I would assume include it in the i
24 technical specifications and allow some reasonable 25 down-time and for repair.
71 1
If they exceed it, then, yes, they'd have to 2
shut down if they are able to repair it within that 3
period of time, just as they have for the on-site 4
diesels today.
Exactly the same philosophy.
5 CHAIRMAN ZECH:
Let me emphasize one other 6
point, too.
If we step back and see what we're 7
really trying to do in station blackout, of course, 8
as we know, it's a loss of power on-site as well as 9
off-site and the main thing that concerns all of us i
10 would be to keep that core covered.
That means we 11 need water, and in order to keep the core covered, we 12 need power and that's really fundamentally rhat we're l
13 talking about and that's why.it's such an important i
4 14 issue.
15 Whenever we have a real potential station 16 blackout, the first thing I think about is how is the j
i 17 power situation because you got to get water to cover 18 the core.
And I know you -- this is what it's all 19 about and so it really is an important issue and I 20 think our efforts to enhance the safety in this J
21 regard is absolutely the right thing to do.
22 I,
too, though, would like to make a 23 reference to the schedule.
I certainly hope we could
)
24 speed up that schedule.
I recognize there's many i
25 things involved that need to be analyzed and so
72 1
forth, but I would certainly encourage the utilities 2
to take the initiative to speed up that schedule.
I 3
think it's important.
4 If I were a utility executive, I would 5
certainly want to make sure that my facility would 6
adopt these enhanced safety measures and so that in 7
the middle of the night if I were a utility executive 8
and they called me, I would not have to think about a 9
shortage of power.
I'd like to think I had extra 10 power.
I think if I were a utility executive, I'd 11 put in not only an extra diesel engine but maybe two 12 of them or maybe three.
To me it's well worth the 13 assurance that you're going to have power.
14 So I think we are doing the right thing and 15 I hope the utilities will I think it's in their 16 own best interest to add this enhanced safety to 17 their plants.
18 So, I would also like to say to my fellow 19 Commissioners that we have heard the briefing now.
20 We all had a chance to think about this for a 21 considerable period of time.
He reflect on what 22 we've heard and make any comments we may have to the 23 Staff and perhaps we can move forward with this very 24 important rulemaking issue.
25 Are there any other comments?
j
73 J
1
[No response.]
2 CHAIRMAN ZECH:
All right..
With that we'll 3
stand adjourned.
Thank you for a very fine briefing.
4 (Whereupon at 11:33 a.m.,
the meeting was F
5 adjourned.)
6 7
4 8
9 10 11 12 l
13 14 15 16 17 18 19 20 21 22 23 24 25 1
l l
i CERTIFICATE OF TRANSCRIBER This is to certify that the attached events of a meeting of the U.S. Nuclear Regulatory Commission entitled:
i TITLE OF MEETING: Proposed Final Rule on Station Blackout PLACE OF MEETING:
Washington, D.C.
DATE OF MEETING:
Thursday, March 31, 1988 j
were transcribed by me.
I further certify that said l
transcription is accurate and complete, to the best of my ability, and that the transcript is a true and accurate record of the foregoing events.
I d-u f =...' RODRI s
- ~~
MARIO A.
's 2s Ann Riley & Associates, Ltd.
4
]
1 I
i 1
5 STATION BLACK 0UT (UNRESOLVED SAFETY ISSUE A-44) i C0mlSSION BRIEFING MARCH 31, 1988 i
- l i
i i
THEMIS P, SPEIS I
WARREN MINNERS l
ALECK SERK!Z OFFICE OF NUCLEAR REGULATORY RESEARCH I
i
~
i ASHOK THA!WJI FAUST ROSA 0FFICE OF NUCLEAR REACTOR REGULATION 1
l
BRIEFING OUTLINE i
DEVELOPE NT OF RULE:
Slft%RY no REC 0f100ATION 1.
i USI A-44 SAFETY CONCERNS 2
Slft%RY OF STAFF FINDINGS 3
l PROPOSED RESOLUTION 4
2 AAC BENEFITS 5
l 10 CFR 50,63 REC 8JIREE NTS 6
1 IWLEIENTATION OF RULE:
REVIEW PRIORITIES 7
)
SB0 REVIEW PROCESS 8
J SCHEDULE 9
i
1
^
Slft%RY AND REC 0ftENDATION COMISSION DECISION TO ISSUE PROPOSED STATION MARCH 5, 1986 BLACXOUT RULE FOR COM EtiT PUBLIC CottCNTS CONSIDERED AND If4CORPORATED l
AS APPROPRIATE ACRS AND CRGR REVIEWS JUNE 9, 1987 JUtlE 23, 1987 l
t DISCUSS 10f1 WITH Nll'%RC'S WORKING GROUP SPRING - FALL ON STATION BLACKOUT (NUGSB0).
INDUSTRY tlew 1987 AGREES WITH PROPOSED RESOLUTION I
STAFF RECOWEt1DS THAT Com!SSION ISSUE FlflAL RULE 1
USI A-44 SAFETY CONCERNS t
1 1.
STATI0f4 BLACKOUT (SB0) MEANS COMPLETE LOSS OF AC POWER TO ESSEliTIAL AND NON-ESSEf1TIAL' BUSES (LOSS OF OFFSITE POWER NiD THE UNAVAILABILITY OF THE ONSITE EfERGENCY AC POWER SYSTEM).
2.
LIMITEDDECAYHEATREf0 VAL (EHR)Af1DNOCONTAINMENTHEATREMOVAL(CHR) 1 W/0 AC POWER.
j 3.
SEVERE \\ GATHER CONDITIONS (E.G., HURRICANES, ICE STORMS, TORNAD0ES) ARE MAJOR C0ffTRIBUTORS TO LOSS-OF-OFFSITE POWER (LOOP),
4.
ESTIt%TED RANGE OF FREQUENCY OF SB0 IS 1E-3 T01E-5/Rx-YR.
{
l 5.
EST!f%TED RANGE OF CONTRIBUTION OF SB0 TO CORE DAf%GE FREQUEf1CY (CDF) is [
IE-4 TO 1E-6/Rx-YR.
I t
6.
EXTEllDED DURATION SBOS ( > 2 mS) CAff BE SIGNIFICANT CONTRIBUTORS TO RISK.
L l
i I
PRESENTLY THERE IS NO REGULATORY REQUIREMENT FOR PLAfiTS TO COPE WITH STATION i'
BLACK 0UT.
1 l
1 2
l 1
m
i SUWARY OF STAFF FINDINGS i
(NUREGS-1032 8 -1109)
RELIABILITY OF ONSITE DERGENCY AC POWER SYSTEMS VARIES CONSIDERA PLANT DESIGN AND C0f! FIGURATION EMERGENCY DIESEL GENERATOR RELIABILITY AND CONFIGURATION i
t Com0N CAUSE FAILURES FREQUENCY AND DURATION OF OFFSITE POWER LOSS VARY CONSIDERABLY i
SITE CHARACTERISTICS (WEATHER, GRID) t PLANT FACTORS (SWITCHYARD DESIGN, TRANSMI3SION LINES)
CORE DAMAGE FREQUENCY CAN VARY CONSIDERABLY FROM PLAE TO PLANT SUSCEPTIBILITY TO STATION BLACK 0UT (SBO)
ABILITY TO COPE WITH LOSS OF ALL AC POWER PROPOSED RESOLUTION CONSIDERS PLA W UNIQUE CHARACTERISTICS AND PROVIDE A COST EFFECTIVE WAY OF ACHIEVING A PLANT SPECIFIC SOLUTION 3
PROPOSED RESOLUTION I
1)
AMEllD 10CFR50 BY ADDING SECTION 50.63, "LOSS OF ALL ALTERfMT!?lG CURRENT POWER," WHICH REQUIRES THAT ALL PLNITS BE ABLE TO COPE WITH STATION BLACK 0UT (SB0) FOR A SPECIFIED DURATION. AN ALTERNATE AC SOURCE IS N1 ACCEPTABLE OPTION.
2)
THE STAFF PREFERS THE ALTERNATE AC SOURCE OPTION DUE TO ADDITI0fML SAFETY BENEFITS 3)
ISSUE REG 1.155, "STATION BLACKOUT" WHICH PROVIDES:
GUIDANCE FOR SEVERE WEATHER CATEGORIES, REQUIRED LEVELS OF EDG RELIABILITY AND OTHER RELATED ASSLfiPT10tlS.
GUIDAllCE FOR SB0 AtMLYSES, PROCEDURES, NID TRAINING FOR COPING WITH SB0, AND 0/A CONSIDERATIONS RELATED TO ALTEPJMTE AC SOURCES.
GUIDANCE ON THE USE OF ALTERtMTE AC SOURCES.
GUIDANCE ON EDG RELIABILITY tONITORING AND RELIABILITY PROGRAM.
4
[
ADDITIONAL BENEFITS OF ALTERNATE AC 1)
PROVIDES A MEAtlS TO COPE WITH RCP SEAL FAILURE (GSI-23)1 CAN BE USED TO POWER AN IflDEPENDENT PUMP SEAL COOLING SYSTEM.
2)
S!?fLIFIES OPERATOR ACTIONS NEEDED.TO COPE WITH $80.
i 3)
ALLEVIATES EfNIRONMENTAL CONCERtlS ASSOCIATED WITH SB0 l
(E.G., OVEPHEATING OF ELECTRICAL EQUIPMENT AND CONTROL ROCM HABITABILITY).
ADDITIONAL RECOB E NDATION I
THE STAFF REC 0ft1Ef0S ADDitJG THE FOLLOWING SENTEf1CE TO 50.63, SECTiON C.2:
"lF THE POTEtlTIAL FOR C0fti0t1 MODE FAILURES CAN BE MINIMIZED, USE OF AN ALTERf! ATE AC SOURCE IS A PREFERRED q
OPTI0fl S!tJCE THIS APPROACH WILL ALSO BEf1EFIT OTHER SAFETY l
CONCERNS."
i 4
5
f 50.63 REQUIREE NTS LOSS OF ALL ALTERf4ATING CURREtiT POWER 1.
EACH LICEllSED LWR PLMIT f4JST BE ABLE TO WITHSTNO FOR A SPECIFIED DURATI0ft NO RECOVER FRCN A STATION BLACKOUT.
2.
STATION BLACKOUT DURATION SHALL BE BASED ON:
(!)
REDUf0ANCY OF ONSITE EMERGEf4CY AC POWER SOURCES.
(!I) RELIABILIT( OF ONSITE EtERGENCY AC POWER SOURCES, I
(!!!) EXPECTED FREQUENCY OF LOSS OF OFFSITE POWER.
i (iv) PROBABLE TIME TO RESTORE OFFSITE POWER.
3.
USE OF ALTERNATE AC POWER SOURCES IS N1 OPT 10f4 PROVIDED C0f0!TIOfis STATED Ifl THE RULE ARE ffT.
I4, RG 1.155 PROVIDES GUIDAf4CE FOR COMPLY!f1G WITH THE RULE.
6
REVIEW PRIORITIES BASED ON RELATIVE SAFETY SIGNIFICANCE SUSCEPTIBILITY To STAT 10tl BLACK 0UT (~ 17 UllITS)
OTHER FACTORS ALTERf4 ATE AC SOURCE PROPOSALS MARK 1 AtlD ICE C0tlDEriSER C0!ITAltlMErlTS 7
SB0 PEVIEW PROCESS THE STAFF REVIEW WILL ASCERTAltl THAT THE GUIDELINES OF RG 1.155 HAVE BEEN IMPLEMENTED.
THE REVIEW WILL FOCUS ON:
THE DETERMINATION OF THE PROPOSED MINIMUM ACCEPTABLE SB0 DURATION o
OFFSITE AC POWER CHARACTERISTICS ONSITE EMERGENCY AC POWER CHARACTERISTICS EMERGENCY DIESEL GENERATOR RELIABILITY o
SB0 COPING CAPABILITY DECAY HEAT REMOVAL EoVIPM$NT ErivlRollMENT INCLUDillG CotlTROL Room o
POTENTIAL MODIFICATIONS ALTERNATE AC SOURCE REACToe COOLANT PUMP SEAL FAILUP.E BATTERY CAPACITY CONDENSATE STORAGE CAPACITY o
PROCEDURES AND TRAINING FOR SB0 o
OPERABILITY REQUIREMENTS FOR SB0 ECUIPMENT 8
a NRR SB0 IEVIRI AND IMIXNTATI(N SOMIF a_ FI SS II 8' rv 9e rv 9i y:";
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$2 c
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SB0 Pa E STAFFEVALUATIm STAFF EVALUATim IWLDENTATIG
[WLEMENTATIN ISSUED CaPLETE) FOR 24 Ep RR COMPL TED fm f0FLETEDfp (ASSUMED)
HIGEST 3RIM ITY IEXT blTES 24 lIGEST REMAINING 10 SITES PRIORITYSITES blTES ALL SITE RESPWSES RE&IVED STAFFEVALUATIm IWLEMENTATION f
E CDP FOR REMAINING lb SITES 9
i
-