Text

Transcript of 870206 Briefing on Chernobyl in Washington,Dc. Related Documentation Encl.Pp 1-68
	ML20210T885
Person / Time
Issue date:	02/06/1987
From:	; NRC COMMISSION (OCM)
To:	;
References
	REF-10CFR9.7 NUDOCS 8702180333
	Download: ML20210T885 (85)
	v • d • e

!'

ORIGINAL I

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION

~

Title:

Briefing on Chernobyl (Public Meeting)

Location:

Washington, D.

C.

Date:

Friday, February 6, 1987

't Pages:

1 - 68 t

I s

j 870210g3g870206 3

$9". 7 PDR N

Ann Riley'& Associates Court Reportery 1625 1. Street, N.W., Suite 921

(~

Washington, D.C. 20006

~

(202) 293-3950

..w

4 1

D I SCLA 1 MER 2

3 4

5 6

This is an unofficial transcript of a meeting of the-7 United States Nuclear Regulatory Commission held on e

2/06/87 In the Commission's office at 1717 H Street, 9

'ii. tJ., Washington, D.C.

The meeting was open to public 10 attendance and observation.

This transcript.has not been 11 reviewed, corrected, or edited, and it may contain

f 3

12 i naccurac i es.

13 The transcript is intended solely fer general 1

14 informational purposes.

As provided by 10 CFR 9.103, it is 15 not part of the formal or informal record of decision of the 16 matters discussed.

Expressions of opinion 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 19 any proceeding as the result of or addressed to any statement 20 or argument contained herein, except as the Commission may 21 authorize.

22 23 24 a

25

_]

^

- +

1

.s 1

UNITED STATES OF AMERICA 1,.a

, ~,

2 NUCLEAR REGULATORY COMMISSION 3

4-BRIEFING ON CHERNOBYL -

5 6

(PUBLIC MEETING]

7 8

Nuclear Regulatory Commission J'

9

. Room 1130 10 1717 H Street, Northwest 11 Washington, D.C.

12 13 Friday, February 6, 1987 s

14 15 The Commission met in open session, pursuant to 16 notice, at 10:06 a.m., the Honorable LANDO W. ZECH, JR.,

)

i 17 Chairman of the Commission, presiding.

18 COMMISSIONERS PRESENT:

3 19 LANDO W. ZECH, JR.,

Chairman of the Commission 20 THOMAS M. ROBERTS, Member of the Commission 21 JAMES K. ASSELSTINE,. Member of dhe Commission 22 FREDERICK M. BERNTHAL, Member of the Commission 23 KENNETH M. CARRj Member of the Commission 24 STAFF AND PRESENTERS SEATED AT THE COMMISSION TABLE:

25 WILLIAM C. PARLER

2 1

SAMUEL J. CHILK 2

VIC STELLO 3

HAROLD DENTON 4

THEMIS SPEIS 5

BRIAN SHERON 6

AUDIENCE SPEAKERS:

7 BRUCE BOGER 8

HOWARD RICHINGS

'l 9

RALPH MEYER 10 SHELDON SCHWARTZ 11 12 13 7

\\.

14 15 16 17 18 19 20 21' 22 23 24 25

3 1

P R o C E'E D I N G S 2

CHAIRMAN ZECH:

Good morning, ladies and gentleman.

3 Today's meeting is an information briefing by idun NRC Staff 4

for the Commission on the U.S.' government factual report on 5

the Chernobyl accident.. The report was completed and q

6 published in January of 1987, and I understand a limited' 7

number of copies are available'at the back of the room.-

8 I might say-that the Commissioners just received 9

this yesterday so we really have to have a little time to 10 study it in more detail ourselves, 11 The NRC Staff this morning will brief the Commission 12 on the contents of the factual report and on the preliminary 13 Chernobyl implications assessment.

This-is an information 14 briefing, I repeat, and no commission votes are anticipated 15 today.

16 Do any of my Commissioners have opening' comments?

17 COMMISSIONER ASSELSTINE:

No.

i 18 CEAIRMAN,ZECH:

All right, Mr. Stallo, will you 19 proceed?

20 MR. STELLO:

Thank you, Mr. Chairman.

There are at 21 least a few points that I think are important to make.

One is 22 the ACRS has had an opportunity to review our views on the 23 implications of the accident, and there were two letters.to 24 that effect which the Commission has copies of.

25 As you already said, the fact-finding report is

4 1

available and there ara' copies in the back of the room.- our 2

report.on the implications has not been released publicly 3

yet.

Our view is -- and we recognize that the Commission has-4 had not a long time -- in fact, only a very, very brief time 5

to even glance at the report.

But what our plans are is to ---

6 and we have suggested to the Commission that we think it's 7

important to get public comment before the Commission takes 8

any final position on this matter.

9 I think that the Commission ought not only have the 10 views of the regulatory Staff before it reaches its final f

11 conclusion, but it ought to have the benefit of public comment 12 which we intend'to be very broad in nature to ensure that i

13 anyone who has anything that they can add, that we have the 14 benefit of whatever additional information or insight that we 15 can get from any source in order to bring that to the 16 Commission for its decision.

17 Finally, on the impact, we recognize that what we're 18 going to say here today is based on our understanding of.the 19 accident based on all the information available to us.

We 20 have attempted and tried faithfully to identify issues even if 21 our instincts were that this issue was resolved.

We decided-22 to still leave the issue there, to consider it, and would err 23 on the side of the further consideration to make sure that we 24 tried to the best of our ability to raise all of the related 25 issus.s and what it might mean to us so that we have the full

~._

l 5

1 benefit of the understanding of that accident.

2 We would urge the Commission to try to determine 3

whether the course that we've laid'out and the comment process 4

is the right one and to get on with that as soon as'we can 5

because I think that there might be a great deal of interest-6 nationally and internationally on what we have said.

7 With that I'll ask Mr~. Denton to begin the briefing 8

and others will join in and we'll be happy to respond to any 9

questions the Commission may have_in either our' implications 10 as we understand them or the accident itself.

You were 11 briefed previously on the accident but now we'll -- though 12 most of what we say today in terms of understanding what'the 13 impact of that accident might mean to us as regulators.

J 14 CHAIRMAN ZECH:

All right, thank you.

Mr. Denton?

15 MR. DENTON:

I'd like to give a short overview, 16 Mr. Chairman, and then ask Dr. Speis to give the details from 17 our effort today.

18 This has been a major effort by the Staff since the 19 accident happened and the reports today that we're providing 20 you have their genesis back with the formation of the

.21 intergovernment, interagency task force when the accident' 22 happened.

23 Since that time the agencies with special expertise 24 in reactor safety and environmental health have periodically 25 met and have pulled together in this report, that we call the 1

..ea,-.

'n-s

-e, 3

--e5

.e

- - - -,,, - - - - + - -.

,-w.

6

.1 factual report, their best views with regard to various 2'

aspects of the accident.

.It relies-heavily on the written

'3 report that the Soviets provided at the IEA meeting.

.I think 4

every author of the factual report attended'the meeting in t

5 Vienna and had the benefit of those direct presentations by 6

the Soviets.

7 We had a number of meetings with the Soviet 8

representatives on various aspects, so the factual report 9

should be viewed as representing the various agencies best 10 efforts to describe what happened and the consequences of what 11 happened.

12 MR. SPEIS:

Next viewgraph, please.

13 (Slide.]

14 MR. DENTON:

It includes a detailed bibliography of i

15 the various materials that we were able to find that described I

16 the reactor and the approach that the Soviets use'to reactor 17 safety.

4 t

18 At the same time we were attempting to describe the 19 accident we formed up a task force under Dr. Speis to 20 determine what the implications of the accident were for the l

21 NRC.

As Vic said, we did not do this with any pre-judgment of 4

l 22 what the issues were.

We tried to take every issue that 23 contributed to the accident -- and we briefed you before on 24 those, such as the lack of attention to detail in performing 25 the test, the human errors, the bypassing of safety systems,

_,, _ - - _ _ _ _ -. ~., _ _.,.. _.. _ -,. _. _.

= -

7 1

the fact that it was a reactivity accident ---and go look at 2

what our practices were and what the implications might be.

3 So we didn't attempt to prejudge when we went-at.

4 And Themis has had between 12 and 40 people at various times 5

working on the various aspects of the Chernobyl implications.

i 6

So you'll find in the implications report a treatment of each j

7 of the elements that were involved in Chernobyl and our 8

assessment of what it might mean.

1 9

As Vic has said and as you are aware, there's no i

i 10 direct nexus between the design of that system and the 11 U.S.

light water reactor.

So it's more taking the issue like 1

1 12 reactivity transients and looking at how we approach it and 13 see what the lessons are.

14 There was a great deal of international cooperation 15 in this effort.

We've met on a number of occasions with the 4

16 Nuclear Energy Agency in Paris which includes essentially all 17 of the countries outside the Soviet Union.

And we coordinated 18 our technical views widely with those.

19 The second slide --

20 MR. SPEIS:

Next viewgraph, please.

21 (Slide.]

22 MR. DENTON:

-- just provides a brief overview of l

23 the factual report.

We've not received essentially any new 24 detailed information since the Vienna meeting, and most of the i

25 time since that time has been reading all the material that is 4

,,r..-__,.-,y-.,,-

,,,.--p.v

,,,,---,,_,,,,----.,,,.,-__,_,--..,-_--.,,r%-m-----

.,-+..

-r--

g-e,-e--

1 8

1-available, background and:doing analyses and' studies and 2

producing this report that we-call the factual report.

3 The next viewgraph gives you sort of an overview of 4

that report.

5

[ Slide.]

j 6

MR. DENTON:

We played the role in compiling this 7

report and publishing it for the agency.

But there is a 8

description in the factual report of the plant design that was 9

provided by-the Department of Energy.

EPRI contributed a 10 chapter on the safety analysis of that RBMK design under 11 various conditions.

We wrote the section on what happened at 12 Chernobyl, the so-called scenario section.

INPO contributed a 13 section on the role of the operating personnel at Chernobyl.

14 We wrote the section on the source term and the atmospheric 15 dispersion issues.

FEMA wrote the'section on the emergency 16 preparedness within the Soviet Union.

And EPA did the 17 assessment of the environmental consequences.

~

d 18 Each chapter in this report is the responsibility of 19 that agency.

We did not attempt to achieve a consensus view, 20 and it's really a compilation of various agencies views.

And i

21 the intent was that each agency would take this report and 22 take whatever lessons it wanted to draw from it in carrying 23 out its own responsibilities.

24 COMMISSIONER ASSELSTINE:

Harold, on that, two of i

25 those organizations are industry organizations.

To what t,,

r,,,_.,-

,,,,y,--.-

,,,_v-,,,

D 1

extent did the Staff review those chapters of the report?

2 MR. DENTON:

We had people, as you know,'in Vienna 3

and we reviewed all the areas ourselves.

But right after 4

Chernobyl when there seemed to be an immense amount of work to 5

be done to pull it all together we said, each person will take i

6 an area to right up.

So we have access to all the same 4

7 information that EPRI or INPO'had.

But as you know, 8

representatives from those two organizations attended the IEA 9

meeting, so with their special expertise we thought they could i

10 write the chapter in there.

i 11 So this is not intended to provide advice and a

12 recommendations to the Commission, but rather just an 13 accounting of what happened at chernobyl.

J 14 COMMISSIONER BERNTHAL:

I think it's also very clear 15

-- although not on the cover and the front page here -- that 16 this is not strictly an NRC document.

17 MR. DENTON:

That's right.

18 COMM SSIONER BERNTHAL:

It carries the NRC 19 imprimatur on the cover but lots of other things on the back.

20 MR. DENTON:

Yes, sir.

Because of our overall 21 interest in all of these areas we sort of took the lead in 22 trying to get out what I call a unified document.

A document 23 that could serve as a reference when people want to look back 24 and determine what happened.

And the implications report was i

25 written by NRC senior management from each of these areas.

l

t 10 1

The next page gives a little bit of background 2

about:the implications report.

3

[ Slide.]-

4 MR. DENTON:.

I've described the resources.

I think 5

overall we spent two or three man-years in writing the 6

implications report all total.

We' assigned principal 7

responsibility of'each one of the'various sub-elements.

We 8

set up a management group consisting of ths. office directors 9

from all of the' senior offices and some of the regions to 10 review the implications report.

11 We had several meetings with the ACRS and you have 12 their letters.

If I had to summarize their letters, I think j

13 they said that the Staff proposals are sound and that they had 14 no major suggested changes in the direction we were going and j

15 we would, as Vic said, propose that you after your review 1

16 authorize the release of that for peer review and public 17 comment.

i 18 The next page just gives a slight overview of the 19 way we approached it.

20 (Slide.]

21 MR. DENTON:

We attempted to identify all the issues 22 that were candidates for examination.. In this we looked at i

23 operations, design, containment, emergency planning, All the 24

' issues that I have previously briefed you on as contributing I

25 to the accident.

We tried to look at what were the present

-..--.I

s 11 1

practices within the. agency, what was the work in progress, 2

and what was our assessment about the implications of that 1

l 3

particular. area for-our approach.

4 I think maybe at this point would be a good time to' 5

turn to Themis and have him take the next slide which are the 6

issues themselves'and give you a bit more detail about what i

7.

issues we actually did examine, and then the remainder of the 8

briefing will be a summary of the conclusions we came to 9

regarding the implications in each issue.

10 CHAIRMAN ZECH:

Now we're talking about the 11 assessment paper now, is that what we're-talking about?

12 MR. DENTON:

No, sir, the implications.

I had not 13 planned to go into the assessment in any more detail because 14 it hasn't changed that much from a briefing I think we gave 15 you.

16 CHAIRMAN ZECH:

All right, so we're talking about 17 this publication; is that right?

18 COMMISSIONER ASSELSTINE:

We're switching from that 19 20 MR. DENTON:

We're switching from the factual' l

21 report, which is basically the information we presented in i

22 September with a lot more supporting documentation and

i 23 references to the implications document.

24 CHAIRMAN ZECH:

All right, fine.

Just make sure we l

25 know what we're addressing.

.)

s 12 j

l 1

MR. STELLO:

The bound document is the one that's in.

~.

4.

2 the back of the room and has been released.

3 CHAIRMAN ZECH:

I understand, fine.

4 MR. STELLO:' The one that the Commission needs to 5

decide on is the implications report which is not publicly l

6 available.

7 CHAIRMAN ZECH:

And that's what we're going to talk 8

about here.

This is the one'we haven't read yet.

i 9

MR. STELLO:

Now we're going to summarize -- this is 10 the one that you have not read yet.

11 CHAIRMAN ZECH:

I haven't-anyway.

I got it 12 yesterday.

i 13 MR. DENTON:

I think there should be few surprises 14 in the factual bound report.

It's basically what we have 15 briefed you on all along, much better summarized and backed up 16 with supporting details.

17 CHAIRMAN ZECH:

Right.

18 COMMISSIONER ASSELSTINE:

But by and large the 19 information base is pretty much the same; the Soviet Union's 20 report and the INSAG report?

21 MR. DENTON:

And our own conversations with a few i

22 representatives.

23 CHAIRMAN ZECH:

So you're telling us we shouldn't be 24 surprised by what we see in here?

25 MR. DENTON:

That's correct.

I noticed there were j

)

s 13 I

some reports in the media about the EPA environmental 2

assessment of the consequences-of-the accident, but they fall 3

within the same range, I think, as we've briefed you 4

previously and have been. reported by Dr. Gale and others.

5 CHAIRMAN ZECH:

Fine.- So now we're going to talk 6

about the assessment.

7 MR. DENTON:

Yes, sir.

8 CHAIRMAN ZECH:

All right, proceed.

Thankyou,Mr.\\ Chairman.

We will be 9

MR. SPEIS:

talking about the implications, our conclusions and the 10 11 approach that we took.

As both Mr. Stallo and Mr. Denton 12 said, the issues selected for evaluation were those with some 13 analogy to the various significant factors of the Chernobyl 14 accident.

And Harold also said that no pre-judgment as to

+

15 whether these analogies are close enough to cause 16 U.S. regulatory concerns.

We let the issue be assessed and 17 then the conclusions will show themselves in a natural 18 fashion.

19 he took every issue and our main objective was to 20 assess every issue separately.

We separated the issue in 21 terms of trying to define the issue as precisely as we could, 22 describe the work in progress, then proceed with the 23 assessment and then proceed to draw conclusions and 24 recommendations on every issue.

25 We were attempting to seek broad or raw conclusions

14 i

1 as the main focus.

Not to get lost in the details even though 4

,m 2

avery issue, as I said, has been assessed separately. LThe 3

report contains a brief summary of the total effort.

And in 4

addition to that, every chapter has an overall assessment of 5

that chapter.

6 Chapter 1, of course, discusses the overall 7

assessment.

Chaptars 2 to 6 go into the details which you 8

will see in the next viewgraph, please.

9

[ Slide.]

10 COMMISSIONER ASSELSTINE:

Themis, one question.

11 obviously, we're not the only ones doing this.

I assume 12 virtually every country with a nuclear power program and 13 particularly those with advanced nuclear programs are looking 14 at Chernobyl for its implications.

15 Do you have a sense based upon discussions that q

16 you've been able to have with other country, particular for 1

17 example, say the European countries for the kinds of issues 18 that they have identified, the kinds of conclusions and 19 recommendations that they are drawing since they have 20 western-style reactors?

And have you been able to do a i

i 21 comparison of what you've been able to come up with both 22 in terms of issues and conclusions and recommendations as 23 compared with what other countries are doing?

24 MR. SPEIS:

Yes, I think we have done a pretty good 25 job.

Our comparisons at this point in time are kind of t

.-_--.-.-_,___--.,_--.-...,.c,

.- =.

15 1-qualitative. The haven't done a very precise, one for one.

We 2

have been participating with them in Nuclear: Energy Agency, 3-CSNI.

CSNI is coming up with its own implications assessment 4

for the European reactors which are mostly similar to..ours.

~

5 That report should be out in the late spring sometime~and all 6

the' countries are participating.

)

7 In addit' ion to that we have had one-to-one contacts 1

8 with the French, with the Germans, with the Swedes, with the i

9 Finns.

And I can say -- maybe Harold can correct me -- that 10 in general.our approach and theirs kind of overlap.

There are 11 no surprises.

They stress some things than others, and I l

12 think some of those things might show up as I go-through the 1

i 13 conclusions of our assessment.

14 COMMISSIONER ASSELSTINE:

Good.

15 MR. DENTON:

I think we've covered almost every one t

i 16 of these issues in international meetings just on those i

i 17 topics as groups of experts.

So I think that aspect has been 18 covered and I think you will find the CSNI report very similar 19 in conclusions to ours.

And we've tried to indicate in this 20 report where there are unique solutions like in the filtered 21 venting area and some others.

I 22 COMMISSIONER ASSELSTINE:

Right.

j 23 CHAIRMAN ZECH:

Now we should point out that there's 4

24 been a number of meetings overseas.

Harold, you've j

l 25 participated.

Themis has too, I know.

So the international

16

.1' effort going on, I think has been one of rather open and-2 candid exchanges.

That's what I understand. 'Could you talk 3

about that just a little bit?

Perhaps the trips you've made j.

4.

overseas and how the international cooperation in this event.

5 is taking place.

6 MR. DENTON:

I think all three of us here at the i

7

. table have been at and participated.in those meetings on-8 several occasions.

And I think the whole international l

9 community felt the need to meet often.and reassess these 10 issues.

So it's been a great deal of meetings, both'in Paris 11 with the Nuclear Energy Agency and in Vienna at the IEA.

And

]

12 I think some of -- we'11' continue to meet on some of the l

13 details of the chernobyl accident, but I don't think the 14 implications will change a heck of a lot from what you hear 15 today.

f 16 CHAIRMAN ZECH:

I think the point is, it's important i

17 to recognize that this has really been an international effort 18 and a lot of countries participating.

Within our own 4

19 government there's been a rather significant contribution by i

20 various branches of the government.

And I think that's 21 important to recognize that it has been internationally as i

22 well as a rather strong U.S. government participation as well 23 as industry and other experts that you've recognized already.

)

24 Let's go ahead.

25 MR. SPEIS:

Thank you.

I have listed in this i

i

-,-__-_,...m,r,

.___,,~,..,m,_,_.._,--.w---,-_.

17 1

viewgraph the areas.that we have. assessed.

You see that we 4

2 have taken a number of important areas like operations and.we 3

have identified seven sub-issues under the area of operations 4

that we have assessed in' great deal.

5 We have, for example, administrative controls to 6

assure that procedures are followed and procedure adequacy.

J

~

7 We have looked at the approval'of tests and other unusual 8

operations, bypassing of safety systems.

These, of course, 9

are issues that all of them have some analogy to the accident

. 10 itself.

Availability of engineering safety features; 2

11 operating staff attitudes towards safety; management systems; i

12 accident management.

13 Under design we have looked very carefully at the l

14 way we evaluate reactivity accidents in our reactors.

Also we 15 have taken a look at the accidents at low power and when shut 16 down and whether -- I will discuss this, of course, in more 17 detail later on.

18 Multiple unit protection, if you have an accident in 19 one unit what are the consequences for the other. unit; are the 4

20 operating personnel protected in the control room, and things 21 of that sort.

And again, I will talk about that in more a

22 detail.

We have looked at fires.

i 23 In the area of containment we have looked at what 24 are we doing and what the lessons of chernobyl for accidents 4

25 that go beyond design basis accidents.

Filtered venting is

--_,,,----,--.m.w,.-c.---,,-,-,,,-,,ri,-w,

,-.-_m-_..m.,.,,,-,y----. -. - -w--.v-w-_-----,-------..%.,.

,,--e p

---e,-yyw,.,,

18

-1 something that some European countries are using to manage 2

some aspects of severe accidents, and this is part of our 4

.3 programs and I will discuss that.

4 COMMISSIONER BERNTHAL:

You say you are going to-i 5

discuss that today?

I 6

MR. SPEIS:

In the summary, I will just give you --

4 I

7 of course, yes.

8 COMMISSIONER BERNTHAL:

You're-going to do very well 9

if you discuss all these things today.

t 10 MR. SPEIS:

I will tell you what our conclusions and 11 what the ongoing programs in some of these areas.

12 Mr. Bernthal, we have programs ongoing and we will be 13 stressing some, or we will be telling you that things -- we 14 feel that what we have been doing are adequate.

These are the 1

15 type of things I'm telling you.

16 CHAIRMAN ZECH:

All right, go right ahead.

We've l

17 got a long way to go.

i j

18 MR. SPEIS:

Emergency planning is an important area l

j 19 that was also discussed in the newspaper this morning.

Severe

]

l 20 accident phenomena; of course, source terms, steam explosions, i

21 combustible gas and graphite moderated reactors.

22 I will start now with -- the next viewgraph will l

23 summarize our conclusions of the implications of the Chernobyl j

24 accident for our reactors.

25 (Slide.]

i

19 1

MR. SPEIS:

I think the most important lesson of the 2

Chernobyl accident is what I have.put down on this viewgraph.

3 I would like to read it.

4 "The Chernobyl accident reminds us of the continuing-5 importance of safe design in both concept and implementation; 4

6 of operational controls, of competence and motivation of plant 7

management and operating staff ~to operate in strict compliance a

with those controls; and, of course, of backup features of 9

defense in depth against potential accidents.

i j

10 "Although a large nuclear power plant accident I

i 11 somewhere in the U.S.

is unlikely because of design and 12 operational features, we cannot relax the care and vigilance t

j 13 that have made it so."

l 14 This most important lesson is shared by both the-i 15 Europeans.

The letter that was sent by the ACRS to

{

16 Mr. Chairman on January 15th basically agrees with that and s

17 stresses that point.

18 The next viewgraph I will summarize some of the i

i 19 other important overall conclusions regarding the regulation I

20 of commercial U.S.

reactors, t

21 (Slide.)

22 MR. SPEIS:

We feel that there is no immediate 23 regulatory action needed as a result of the Chernobyl j

24 accident.

The basis for this is that accidents of the type of j

Chernobyl we feel are precluded by nuclear design, shutdown 25 i

i i

,,,-,,,,-.-.---,,...----,-.,-e,-,--,

,.-n-.

.,-n,-----..e..----n--g.,n-

.--,-,,,-,, _ m-., - -, -, - --,,,,,,- -----

.- ~, -,

20 1

margin, containment and operational controls.'

2 The accident's lessons have been largely anticipated t

3 and accommodated, though further consideration of certain 4

issues would be recommended.

5 We want to reinforce some aspects of requirements 6

already existing or being developed.

For example, areas J

7 involved here include operational controls, emergency planning E

and containment performance.

i 9

We feel that research in some specific-10 j

Chernobyl-lesson areas are needed to provide additional 11 foundation for subsequent consideration of action.

In this i

L 12 category we include some additional work on reactivity.

l 13 accidents -- and I will describe what that means -- accidents 1

14 at low power or shutdown, and some work dealing with source 15 term characteristics.

Some additional phenomena made their 16 appearance in the Chernobyl accident and we feel that we want 17 to take another look at them to see what effect, if any, they l

4 18 have on our assessment of source terms.

19 l

The Chernobyl experience will remain, of course, a 20 continuing part of the background information taken into I

21 account in a variety of reactor safety areas, even apart from j

22 from any actions that may be taken in direct response to it.

23 There's no question that it will always be in our minds a

24 whatever we do in the future.

25 Having provided these overall conclusions, I'd like 1

_ - -., _,.. _ _ _ _ _ _ _ _. - _. -. _. _ __-~ _ _

,.. ~.. _ _. _.. - _ - _ _ _ _. _ _,

21 1

to go into some detail on each one of these areas.

2 CHAIRMAN ZECH:

Go right ahead.

3' MR. SPEIS:

The next viewgraph, please.

4 (Slide.]

5 MR. SPEIS:

I will start with the area of 6

operations.

The principal conclusions for specific issue 7

areas are as follows.

In the-area of operations we-feel that 8

administrative controls based on existing regulatory i

I 9

provisions are generally ~ adequate to assure a safe operating 10 envelope.

When we talk about administrative controls, of 11 course, we mean plant operations and we include the NRC rules 12 and regulations, facility license conditions, technical 13 specifications and procedures that exist in plants.

14 These controls address procedural adequacy and 15 compliance, approval of tests and unusual operations, 16 bypassing of safety systems, engineering safety feature i

17 availability, operating staff attitudes,toward safety, and 18 management systems and accident management.

We have looked at 19 all of these areas in detail and in some of these areas we i

20 have decided that things that we have in place are adequate.

21 But in some other areas we think that some 22 additional things should be looked at, and those areas are l

23 listed below.

Of course, these are in the area of operations.

i d

24 We want to reinforce attention to human factors.

We j

l 25 are recommending that a consideration be given to a high-level

---._,n,,--,-

+-..--n.

.a

-.---n

o 22 1

.on-site nuclear safety manager with no other responsibilities 2

or duties.

This issue has been, of course, discussed 3

previously and the conmission had some views on it.

We want 4

to take another look at it to make sure that the lessons from 5

Chernobyl does not make us change our minds about this.

6 COMMISSIONER ASSELSTINE:

Themis, is that the senior 7

manager.on shift concept?

Is that what you're basically 8

talking about?

i 9

MR. SPEIS:

Yes, exactly.

If you.see our report 10 there are some pluses and minuses discussed there already.

11 And there are concerns if you have a senior management who has 12 all the safety responsibilities the other people might tend to 13 relax.

That's one of the minuses that has been discussed.

14 But anyhow, this is something that we would like to take 15 another look at it basically.

16 COMMISSIONER ASSELSTINE:

But basically what you're 17 talking about is having a degreed engineer on shift in charge 18 of the shift.

19 MR. SPEIS:

Some type of safety crew there.

I don't 20 want to characterize it like that.

21 COMMISSIONER ASSELSTINE:

That's what I want to o

22 know, is it the same as the senior manager on shift, and that 23 was the heart of that concept as I recall.

24 MR. SPEIS:

Generically, yes.

But going into any 25 other details we haven't worked that out yet.

s 23 1

COMMISSIONER ASSELSTINE:

Okay.

2 MR. SPEIS:

Vic, you want to say something?'

3 MR. STELLO:

I think it's just identifying an area 4

that needs more work.

I think it's broader than that.

I 5

think it needs to have consideration of what is the shift 4

6 complement, the training and the expertise and the education 7

of those people as to their commitment to follow procedures, 8

as well as to having someone clearly above them.

9 To say that this recommendation means any more than 10 suggesting that because of the interaction of people at the 11 plant during that accident it raises the question.

It needs 12 more work.

But to suggest that any firm, specific concept is 13 here, I think would be a mischaracterization.

j 14 Especially you have to take into account and 4

15 recognize that there is an issue that we are considering l

16 related to this question as well and all this does is 17 reinforce that it's something that needs very careful looking 18 as an entire concept.

This is a very synoptic way of 19 summarizing it, and it has not been studied to the point that 20 there's any firm recommendation here at all.

21 MR. DENTON:

If I could add, all of these areas were 32 intended to be broad areas.

We didn't want to -- I did not 1

23 task this group with developing detailed, cost effective 24 solutions, but rather identify areas with implications.

The 25 work will be done later if the commission agrees that we've 4

,m.

---__.,r,-

-. -,,,-<+--,,,,- - -,- <

m

,y...,--y.m

.m---.--

,wy,-

,,--m____

-....%~,

y

24 1

identified the proper areas.

2 COMMISSIONER ASSELSTINE:

Okay.

This one, it just i

3 struck me in particular, sounded very specific and I guess 4

that's what I was trying to get a feel for whether you had r

i 5

something broader in mind than the old senior manager on 6

shift.

i 7

CHAIRMAN ZECH:

What they're saying is that it might i

8 be broader than-that'apparently and you haven't come down with j

9 anything too specific yet.

l 10 MR. STEIIC:

That's correct,.yes.

11 CHAIRMAN ZECH:

All right, fine.

Go ahead.

1 I

l 12 MR. SPEIS:

The next area is consideration of a 13 program of preparedness for accident management.

Here we talk i

i 14 about training and procedures for coping with severe core 15 damage and for management of containment.

If you recall, both i

16 the Chernobyl and the TMI plant operators and technical teams 17 were confronted with unexpected events for which they were 18 only partially prepared.

l 19 Now we plan to address this area as part of the

)

20 Commission's severe accident policy implementation.

We plan 21 to -- an integral part of the implementation will be the 22 development of an accident management for each nuclear power j

23 plant.

This is something that will be coming to you.

I 24 The next area is review administrative controls to i

25 strengthen the process of technical reviews and approval of i

,,..__-.._.,_,..,_,,_.___.___.-_...-_-__.-,,__.-.._,-..-=_.._,...-.....__..,_m

-._...--,_--..,,__m,.--...,.

,_e...._

_~

s 25 1

changes, tests, and experiments.

This area presently is 2

handled under 10 CFR 50.59.

Changes are initiated by the 3

licensee and he makes a judgment whether the process can 4

proceed without involving the NRC.

Many thousands of those 5_

things are done over the' period of years.

6 Mostly this process has been very successful, but we 7

have noticed some inconsistencies between plants and there are 8

some issues that need additional attention in this area.

Also 9

the industry has been involved in this area and they will be 10 coming to us with a proposal sometime in the spring, how they l

11 can strengthen further this area.

But we feel that this area l

12 needs some additional attention.

13 COMMISSIONER ASSELSTINE:

Isn't this an' area where, i

i 14 in fact, the trend over the past couple of years has been to b

15 give the licensees more discretion?

Things that come to mind 16 are fire protection, tech specs, as a couple of instances or 17 examples where, in fact what the commission has done has 18 simply turned more over to the licensees in terms of 19 flexibility to make judgments under 50.59.

20 MR. SPEIS:

This is true, but that doesn't mean from j

21 what I said that we want to bring it back to the commission.

22 We want to make sure that --

23 COMMISSIONER ASSELSTINE:

Okay, you're going to look 24 at the process?

25 MR. SPEIS:

Yes, look at the process itself.

f i

l

1 26 1

COMMISSIONER ASSELSTINE:

See if the 50.59 process 2

really is as tight as it should be.

3 MR. SPEIS:

Yes, exactly.

4 COMMISSIONER ASSELSTINE:- Okay.

5 MR. STELLO:

Now you recognize that clearly the i

6 kinds of things that were violated at Chernobyl are clearly i

7 outside of anything that would'even be allowed or permitted or j

d considered under 50.59.

But it's again an extrapolation of a l

l 9

lesson learned to where, are the administrative controls there i

10 for something of far less significance?

Are they good enough j

11 and is it worth considering?

j 12 We have been doing it.

It is an issue that we've i

(.

talked about a number of times in the past, and it just 13 i

j 14 reinforces that this is an area that we want to do more in.

15 This is not new, we've already been doing it.

l 16 COMMISSIONER ASSELSTINE:

I take you're going to 17 look both at the scope of activities covered by 50.59 as well l

18 as the process itself?

i 19 MR. SPEIS:

Yes.

i I

20 COMMISSIONER ASSELSTINE:

Or are you just going to j

21 focus on the process.

22 MR. SPEIS:

Both.

23 COMMISSIONER ASSELSTINE:

Good.

l I

24 CHAIRMAN ZECH:

I'd like to emphasize that the 25 implication should not be that, as far as I'm concerned, we've 1

-,,---,,-y--

.,-.--%-.,,,,-w w--,-w

-w,,,.,,,,-. - - - -.,-,y,i---w-- -, - - -,

_---,y-,,,,,-,v-y,-

, -.,,.,,+,

.w-,_......_m..---,r-

-,-,_,.r--+T

---ev v,w-a,-~~ee

- ic s

27 1

lessened our emphasis in this area.

I think we've tried to i

s

-2 involve the utilities and the industry more in this area.

And 1

3 I think that they have, in my judgment,1made some considerable t

1 4

effort to improve.

v.

.i 5

So I think what we're looking for is overall 6

improvement.- And I think the review that you've suggested is 7

entirely appropriate.

But I don't think we should feel that 8

we haven,'t given this a fair amount of emphasis.

And I think 9

the utilities should get the credit for a fair amount of 10 initiative they've taken in this area to strengthen that.

But s

1 11 we'll see what your review brings forward and I think we s

12 should look at'it very' candidly.

i

,\\

13 MR. SPEIS:

As I.said, Mr. Chairman, the AIF will be i

comingwithaproposalsome$1meinthenextfewmonths.

l 14 They l

15 have been undergoing -- they've been doing this review --

b 16 CHAIRMAN ZECH:

Review is appropriate.

We want to i

17 do better if we can.

That's all there is to it, and that's 18 what you're telling us, I guess.

l 19 MR. SPEIS:

Yes.

1 20 MR. STELLO:

That's correct, exactly.

4 5

s 21 CHAIRMAN ZECH:

Okay, go ahead.

i 22 MR. SPEIS:

The next area that we want to take a 23 look at is review the engineering safety feature safety system

'l 24 status displays and availability for potential worthwhile P

l 25 improvements.

s

(

J

-__m,._--.~

,_.._.m_--

.... - -,. -,..~

28 1

There is a question here'about the -- excuse me,-I 2

was going to amplify this about the safety analysis and 3

technical specifications.

The safety analysis sometimes, 4

especially from low power -- which.I'll discuss later on --

4 i

5 whether it is bounding and whether appropriate consideration q

6

.is taken of some engineering safety features which are not'in 7

place at that time'when you at some months of low power, and 8

we want to take another look at this area.

9

. COMMISSIONER ASSELSTINE:

I was just going to ask a 10 little bit more what you had in mind in terms of the safety l

11 system display systems; elaborate a little bit on the kinds of i

12 things you're interested in looking at there.

9 mat's not i

13 covered now by our safety system display systems that you're 14 interested in taking a look at and how you tied that back into 15 the accident?

16 MR. SPEIS:

I would like to call up one of our key j

17 reviewers in this area, Bruce Boger.

1 I

18 CHAIRMAN ZECH:

Come up to the microphone and 19 identify yourself, please.

20 MR. BOGER:

I'm Bruce Boger from the NRC Staff.

l l

21 Basically in this area we're taking a look at the types of j

22 indications that are available to indicate that equipment is j

23 out of service.

This was ongoing work before the accident,

[

24 but I think it keyed in on which aspects we need to really 25 take another look at, and in fact, whether or not to take a 1

29 1

look at the older plants as well.

2 COMMISSIONER ASSELSTINE:

Okay, thanks.

i 3

MR. SPEIS:

The next viewgraph, please.

4 (Slide.]

5 MR. SPEIS:

We'll be addressing now the areas of i

l 6

design, and the first issue will be -- issue identified, II.1,

[

7 reactivity accidents.

8 Positive void coefficients,-of course, had a central 9

role in the cause and course of the Chernobyl accident.

These 10 positive void coefficients are generally absent in commercial I

11 U.S. reactors.

The nuclear design of U.S. reactors provides 12 assurance against a Chernobyl-type superprompt critical 13 excursion.

But we feel -- the group that did the work -- that i

14 we should review the risk from specific sequences by using PRA 15 and other deterministic tools.

i 16 What I mean by this, when we make judgments about i

i l

j 17 what type of reartivity insertions are creditable or possible 18 these judgments, of course, have been based on engineering l

19 '

analysis, whether the design is such that it prevents rapid 20 ejections or rapid withdrawals.

Even though if you start 21 postulating multiple failures it is possible to introduce 22 additional reactivity into the system.

23 So we want to sit back and take a broader look into 24 this whole area of using a PRA perspective, assuming failures l

25 and trying to judge what type of probabilities we can

.,,--e

e-.--

-=

" " ~ ~ ' ' '

i 30 1

associate with those failures.

Those type of things have been 2

looked at in the past, but again, we felt that we wanted to 3

take another look.

And our ' initial judgment is that this 4

expedition or this search is not going to return anything, but 5

we feel it's such an important area that we want to take 6

another look and document the basis of our findings.

7 CHAIRMAN ZECH:

Good.

8 COMMISSIONER BERNTHAL:.

I wish you could be ever so 9

slightly more specific about your specific sequences.

I 10 presume that there is no sequence that we have in mind here 11 and that you are talking about, for example, where one can 12 achieve the apparent prompt criticality that seems to have 13 cccurred in the Chernobyl incident.

14 What are you talking about?

Are you talking about 15 return to criticality, or what are we talking about here?

16 Under certain sequences, I assume that's what you're talking 17 about.

18 MR. SPEIS:

We are talking basically, for example, l

19 possibilities of unlimited boron dilution that will take you 20 back to criticality.

21 COMMISSIONER BERNTHAL:

Okay, right.

22 MR. SPEIS:

So that's one example.

23 COMMISSIONER BERNTHAL:

But there's no sequence, I 24 assume -- or tell me if X'm wrong -- that would envision the 25 prompt criticality that seems to have characterized the

31 1

Chernobyl event.

2 MR. SPEIS:

There are some extreme situations if you 3

assumed many failures to take place simultaneously you can 4

even get to that situation.

I would like to have Mr. Richings 5

give --

6 COMMISSIONER ASSELSTINE:

You're saying it is l

l 7

possible?

[

8 COMMISSIONER BERNTHAL:

But not reasonably credible.

9 MR. SPEIS:

It is not credible.

Anything is 10 possible.

l 11 MR. DENTON:

Plants are designed for ejection of a 12 single control rod, for example.

If you postulate multiple 13 control rods and you insert the reactivity, that way you can 14 get enough to be prompt critical, but it involves failure of

\\

15 all the housings and more than one housing.

So that's the 16 kind of issue.

In boiling water reactors, remember we have 17 grid support structure underneath the control rods.

i d

18 So it's those issues which have been considered in 19 the past often.

And I think you might have the feeling we're 20 reaching at some of these areas.

It's not that we've 21 identified a specific troublesome sequence.

It's more that 22 these certain aspects are worthy of a second look.

23 With more boron dilution, you could add a lot of 24 reactivity by boron dilution but we have a lot of controls to 25 prevent it.

So that's the concern.

O 32 1

CHAIRMAN ZECH:

All right, come to the microphone, 2

please, and identify yourself and give us a little more on 3

that subject, please.

4 MR. RICHINGS:. Howard Richings, I review core 5

physics problems.

i 6

CHAIRMAN ZECH:

You're NRC Staff.

I 7

MR. RICH'INGS:

NRC Staff.

It can't be said that I

8 some of our standard events do not reach prompt critical.

A 9

rod ejection accident or a rod drop accident can, indeed, 10 reach and go above prompt critical.

11 These events are turned around by inherent 12 characteristics of the core, primarily Doppler, and are 13 controlled by the scram characteristics which are much faster

(

14 than the Chernobyl-type scram characteristics.

And that is l

15 one of the things that makes a primary difference in the 16 control of large reactivity accidents in our reactors.

17 But what we are indeed looking at are extremes of 18 compounded errors, compounded mechanical-failures, which gets 19 beyond the standard events, an example being multiple rod 20 ejection, multiple rod drop, to see whether they can indeed 21 occur with any reasonable probability, and then what their 22 consequences might be.

l 23 We have done calculations which are relevant to 24 those, in the past, and our indications are you can indeed 25 survive many multiple failures without really getting into a

33 1

Chernobyl-like event.

But that's what we want to look at.

2 CHAIRMAN ZECH:

Thank you.

3 MR. SPEIS:

The next area that we're proposing to 4

take another look is accidents at low power and shutdown.

5 COMMISSIONER ASSELSTINE:

Themis, before you leave 6

the reactivity accidents, the report says that positive void 7

coefficients are sheent in commercial U.S.

reactors.

Is that 8

true at all times in the life of the core?

9 MR. SPEIS:

It is generally true, but there are some 10 points in time where the coefficient is slightly positive.

11 Mr. Richings, do you want to pursue this further?

12 CHAIRMAN ZECH:

Go ahead, please.

13 MR. RICHINGS:

There are ranges of operations in 14 which the moderator coefficients can be positive.

This is 15 particular true of PWRs, particularly at beginning of cycle, 16 particularly at lower power operation.

It's very uncommon to 17 be true at full power operations in any of these reactors.

18 But there are events analyzed, if the reactors are 19 allowed to operate with positive coefficients, that events are 20 analyzed with positive coefficients.

The coefficients are 21 small, in general, compared to what was involved with 22 Chernobyl and they do turn around as power rises, which did 23 not appear to be a characteristic of the Chernobyl event, 24 though the coefficients for Chernobyl are still not very clear 25 to anybody.

Calculations of those are difficult.

I e

34 1

COMMISSIONER BERNTHAL:

When you say-they turn 2

around, you mean they'rs self-correcting?

3 MR. RICHINGS:

They become negative as power rises, 4

yes.

5 COMMISSIONER ASSELSTINE:

Also we keep talking about 6

prompt criticality and in the report you say the 7

Chernobyl-type superprompt critical excursion.

Does that mean 8

the accident was like a nuclear explosion?

9 MR. SPEIS:

No.

We mean that the reactivity 10 insertion was about -- the timing between a nuclear explosion 11 and the Chernobyl event, which was superprompt is hundreds or q

l l

12 thousands of magnitude in terms of-power rise.

It's

)

13 nanoseconds versus milliseconds.

14 CHAIRMAN ZECH:

All right, proceed.

15 MR. SPEIS:

Accidents in low power and shutdown, we 16 want to take another look, in view of presumption sometimes 17 that full power operations limits -- I think I discussed this 18 already -- especially for particular situations in which not 19 all full power engineering safety features are available.

20 Getting into the next area, multiple unit 21 protection.

We want to make sure that if an accident takes 22 place in one unit of a multi-unit site the people running the 23 plant are able to bring the plant down -- shut down the plant 24 properly.

And of course, we have regulations in place, but we 25 want to take another look to make sure that a severe accident l

l

-~

1

~

35 l

i source term is properly accounted for in this type of.

l 2'

situation.

3 We plan to use source terms that we calculate from i

4 our new methodology that has been put in place, and use.those l

5 source terms to see is there any impact on the control room of 6

a plant situated next to another plant that experienced the 4

l

~

7 accident.

8 We are proposing that for future plants, systems 9

should not be shared.

For example, the thing that happened at 10 Chernobyl, the common ventilation ducts led to the 11 radioactivity and other hot gases escape from Unit 4 into Unit 12 3.

So we are proposing that at least for future plants this 13 sharing is eliminated between plants and multi-unit sites.

14 COMMISSIONER BERNTHAL:

Back to back control rooms i

15 would be out?

16 COMMISSIONER ASSELSTINE:

Or common control rooms?

j 17 COMMISSIONER BERNTHAL:

Is that what you're saying?

l 18 MR. SPEIS:

No.

No, I'm not saying.that.

I'm i

19 saying common ducts.

This is something that'we're going to 4

20 take another look at it.

Again, as Harold said, it's a broad 21 area but we feel that some systems:that are shared, maybe it's 22 cost effective to eliminate them on new plants.

23 COMMISSIONER BERNTHAL:

What about safety systems-24 though where you have -- something I guess I've always s

25 believed and have urged from time to time that you have lots 4

snn~--

~, ~.,, -.

-n

-.--.,w,,,_

e,,,,-

36 1

of possibilities for coping with a situation.

I'm big on 2

multiple coping capability.

3 For example, if yon have diesels on -- you have two-4 plants on one site and you have three emergency diesels 5

perhaps with each plant.

Typically, there's no way that you 6

can interconnect those if push really came to shove and you 7

had a serious problem and for some reason you had multiple 8

failures at one plant.

9 Does that mean that you would prohibit 10 cross-connecting safety systems of that type?

11 MR. SPEIS:

No.

12 COMMISSIONER BERNTRAL:

I would hope not.

13 MR. SPEIS:

No.

In fact, I mentioned passive 14 systens like ducts.

That's an area, as I say, we're going to 15 take a good look at it.

But it could go also in the other 16 direction, and that's the direction that we would probably be 17 going as part of resolving A-44 station blackout; that some of 18 those things should be allowed basically to happen.

19 COMMISSIONER BERNTHAL:

You're basically talking 20 about any system that would allow a pathway for the 21 consequences of one accident to reach the other plant.

22 MR. SPEIS:

To really affect the other plant in such 23 a way that you're not able to bring the plant into a safe 24 shutdown condition.

25 COMMISSIONER ASSELSTINE:

Themis, are you also

37' 1

talking about though plants that have. shared safety systems, a

~

2 common set of safety systems for multiple units,;1ike the 3

emergency feedwater systems or the emergency diesel generator 4

system at Turkey Point for example; avoiding that' type of 5

situation?

Or is it just the common pathways for radiation?

6 MR. DENTON:

I think there are two issues.- One, the 7

need to intertie has been a question around long before 8

Chernobyl.

The thrust of this was, I think with regard to the 9

consequences and the possibility of contamination preventing 10 successful operation.

So it wasn't intended to be a broad 11 study that maybe deserves study by itself.

But just to be 12 sure that if you had systems that failed and areas i

13 contaminated you could take the proper actions.

l 14 MR. SPEIS:

But the overall objective is not to 15 reduce safety.

If interties and things of that sort help you, 16 they should be allowed.

If not and the judgment is made that-17 they hinder safety, then --

18 COMMISSIONER ASSELSTINE:

Yes.

19 MR. SPEIS:

So it's just the overall concept, we're 20 not going in one direction or the other.

21 COMMISSIONER ASSELSTINE:

I'm not talking about the 22 intertie situation so much as the shared --

23 MR. STELLO:

There is no yesEor no answer to the 24 question.

There is no better way for any particular 25 arrangement.

Interties have been'shown to be significant

38 I

contributors t'o risk and they've also shown to he significant.

2 contributors to reducing risk depending. n how it's done..You 3

have to allow for the option, but you have to be very careful 4

if.-you do it.

5 I think you're going to see when we get to a 6

briefing later on 1150 where these kinds of issues come up 7

again and you'll be able to see it quantitatively what that 8

means.

9 COMMISSIONER ASSELSTINE:

Do we have an-idea how 10 many of the 107 plants in this country that now have one form 11 or another of an operating license have shared systems that 12 are part of the shutdown capability?

Obviously, the single-13 unit sites won't.

But what percentage of the multiple unit 14 sites?

Do we know or not?

15 MR. DENTON:

I'd be happy to get back to you.

If f

16 you take it to mean all the way through swing' diesels and that 17 kind of thing and ventilation systems, I think many dual sites 18 have some shared systems.

But overall, the Staff has tried to 19 keep them separate.

So you have to explore it in some 20 detail.

Plants like Palo Verde are truly separate.. Dresden 21 2,

3 probably has quite a fcw. systems that can be shared.

22 And we don't want to stretch Chernobyl to -- I mean, t

23 what we were looking at here was the lessons just from 24 Chernobyl in this report.

25 COMMISSIONER BERNTHAL:

I guess the bottom line here i

i

~^c'

. 39 1

is that I'm not sure that that sentence is quite what yut 'want p

2 to say.

That there is a flat rule that you never want to

-3 share systems that are part of the shutdown capability 4

because, for example, I think diesels in a station blackout 5

circumstance could be considered part of shutdown capability.

6 And'I would not want to make a statement like that-in that 7

circumstance.

8 MR. SPEIS:

We share that.

It could have been 9

worded better.

10 Under fires -- of course, there was a fire at the 11 chernobyl accident immediately following the prompt reactivity 12 excursion.

One of the difficult problems facing the Soviets 13 was fighting that fire and extinguishing it.

And the problem, 14 of course, was compounded with the presence of radiation.

15 our people have taken a good look in this area and 16 we feel that this area has been -- it doesn't nesd any 17 additional work.

We have to keep this always.in our minds.

t 18 The way we approach the issue of fires, you know, defense in 19 depth, prevention, detection, and of course, availability of 20 essential plant safety systems even if a fire takes place.

21 So we feel that the lessons of~chernobyl, as I said, 22 we look at them very carefully what happened there, how the 23 fires were extinguished.

But_we think in this area that the 24 regulations and the process that we have in place is adequate.

25 The next viewgraph, please.

i i

i w

w i-r

-r---

Tr

--m y

d-er+

e e

-+o e

.we+

m

-a

~. _,

<40 O

1

[ Slide.)

2 MR. SPEIS:

I'll get into the containment area now.

3 It's an area that, as Mr. Stallo said, will be discussed in 4

great detail when we come to brief you on the results of 5

1150.

But basically, the performance of containments in 6

severe accidents exceeding the design basis-is under review as 7

part of the imple' mentation of the Commission's severe accident 8

policy.

Everybody knows that containments are important.

9 Again, we will be talking to you more about this.

I 10 don't think there is anything to learn from Chernobyl except 11 what we already knew.

The policy statement of the commission 12 of two years stressed the fact.

13 One of the things that we will be doing and coming 14 to you is to proceed with an individual plant examination that 15 will look for vulnerabilities both at the front end.

or look 16 at the systems that contribute to core damage or core melt, 17 and also look at the containments and see what type of i

18 balance, what additional things can be done to reduce both the

)

19 core melt vulnerability as well as the vulnerability to the 20 containment.

21 It's going to be, as Vic has said many times to you, 22 it's going to be a difficult decision.

You know, where do you 23 put your money.

But a proper balance has to be reached.

But 24 this is an ongoing effort and all of us are sensitive to 1

25 this.

And as I said, it told us again but it was nothing

41 1

new. -We all knew about it.

s 2

The reason we have put down specifically.the issue 3

of filtered venting, the Europeans - -some of the Europeans 4

have or are also planning to implement venting as a strategy 5

to prevent containment failure for some sequences.

We are 6

also looking at that.

So'there is nothing new here.

We just l

7 want to make sure that --

8 COMMISSIONER BERNTHAL:

What is the status of the 9

French initiative in that area?

The Swedes, at least at one 10 plant, have put in a Cadillac system.

But I understand the 11 French are looking at a Renault system.

Could you tell us a 12 little more about that?

13 MR. DENTON:

I'll speak to that, Themis.

I visited 14 one of the plants that they do plan to install their filter at l

15 and they said, I think, by the end of next year they intended 4

16 to have their sand filter installed at all of the plants.

17 COMMISSIONER BERNTHAL:

By next year.

18 MR. DENTON:

By the and of next year.

And it's a 19 reasonably straightforward filter of sand about a meter deep 20 and 40 square meters in surface area using an existing 21 penetration on the containment.

They tend to have two-unit 22 sites, so they have one filter per site.

23 And the authority to open and vent through the 24 filter would have to come from Paris in their scheme, and it s_

25 would be vented through stacks at the site.

And they're still

42 1

developing the detailed procedures for the use of the filters, 2

but the filters are being manufactured and delivered.

3 COMMISSIONER BERNTHAL:' The cost of that system is 4

still estimated to by roughly a million dollars, or under a~

~

5 million dollars, or well under a million dollars?

6 MR. STELLO:

$300,000.

7 COMMISSIONER-BERNTHAL:

$300,000.

8 MR. SPEIS:

It's somewhere, half a million or 9

something like that, yes.

This doesn't include research-or --

10 MR. DENTON:

It is not being built to Class 1 11 standards, and it's not being designed for earthquakes.

It's 12 a pragmatic sort of approach that they don't think they would 13 need it, but if they do it's one more way to prevent long-term 14 overpressurization in the containment.

15 COMMISSIONER BERNTHAL:

What is the projacted 16 effectiveness of that system?

Have they done a PRA on it?

17 MR. SPEIS:

They haven't done a PRA and they haven't 18 done any risk studies or any cost-effective or how much risk 19 reduction.

20 As you know, Mr. Bernthal, we did such'a study for 21 one of our plants back three or four years ago which was 22 litigated.

And at that time, based on what we knew at that 23 time, we didn't find it to be effective at all.

24 COMMISSIONER BERNTHAL:

By I believe that was for 25 the Cadillac system, wasn't it?

m v

w.,,

n

-,.--n.

n+

43 1

MR. SPEIS:

Yes, it was much more expensive than the 2

French.

But in terms of risk reduction, and as I said earlier 3

and I strongly believe'that we should really take a good look 4

at vulnerabilities and decide where we should put_our money.

l 5

And not just theoretically, just because somebody else is 6

doing something we should arbitrarily go that way. -There was 7

a time --

8 COMMISSIONER BERNTHAL:

No, of course not.

We all 9

agree with that, but we now know the cost.

It will be very 10 important to do the benefit calculation for that system.-

11 MR. DENTON:

And the French weren't alone.

As you 12 know, the Germans were adopting such a system, and the 13 Swedes.

And they did convince me, at least at the one plant I 14 visited, it would have no impact on normal operation.

In 15 other words, they wouldn't know it was there.

It was isolated 16 by several safety class valves and it would only be used in 17 the event of an accident where there was no other alternative 18 to avoiding overpressurization.

19 CHAIRMAN ZECH:

Failproof system you're saying?

20 MR. DENTON:

It's sort of a safety valve on the-21 containment.

22 CHAIRMAN ZECH:

You were convinced it was failproof, i

23 were you, Harold?

24 MR. DENTON:

Since the system wasn't there, it 25 sounds like it could be made reasonably failproof, and they I

44 I

have worried about the same thing.

/~'

2 CHAIRMAN ZECH:

Close to that anyway perhaps.

3 MR. DENTON:

They were putting in two valves in 4

series and would maintain controls on those.

And I think we'd 5

be happy to brief the Commission.later in more detail on all 6

of these systems.

We are attempting to follow those.

7 CHAIRMAN ZECH:

I'm sure we'll want more details on 8

that and looking into it more.

9 COMMISSIONER ASSELSTINE:

Harold, maybe you could 10 just quickly summarize the status of the German metallic f

11 filter effort.

12 MR. DENTON:

My understanding there is that the 13 ministry that regulates. reactors in Germany has required a 14 filter for their newest PWR.

And instead of being made of, 15 basically a sand bed filter which has been used in some DOE 16 facilities in the U.S.,

they're using a stainless steel mesh 17 and they think it has certain improvements over the sand bed 18 filter.

19 In that case, Mr. Chairman, the filter is not 20 directly connected to the containment.

They think they have 21 enough time to connect it later.

So in effect, they are not l

22 breaching containment until they need to, but they're making 23 provisions that if they need the connection all the tools and 24 piping is there and that they would have the time to --

25 CHAIRMAN ZECH:

It's not part of the automatic.

45' 1

.MR. DENTON:

No, it's not automatic and it would 2

require manual installation of a connecting _ piece of piping.

3 COMMISSIONER ASSELSTINE:

So it would be really for 4

later overpressurization.'

5 MR. DENTON:

For late overpressurization failures.

6 MR. SPEIS:

It's part of what they call their 7

emergency procedu'res, basically.

8 CHAIRMAN ZECH:

Very interesting.

We'll want to get 9

SUMMARY

RE. PORT FORMAT:

CHAPTER I:

OVEPALL ASSESSMENT CHAPTERS II-VI:

STATEMENT OF ISSUE AND PRESENT PRACTICE, l

WORK IN PROGRESS, ASSESSMENT, CONCLUSIONS AND.

RECOMMENDATIONS.

l I

N

-. 1

ISSUES I.

OPERATIONS (ADMINISTRATIVE CONTROLS)

I.1 ADMINISTRATIVE _ CONTROLS TO ASSURE'THAT PROCEDURES ARE FOLLOWED, AND PROCEDURE ADEQUACY.

I.2 APPROVAL OF TESTS AND OTHER UNUSUAL OPERATIONS I.3 BYPASSING SAFETY SYSTEMS 1.4 AVAILABILITY OF ENGINEERED SAFETY FEATURES I.5 OPERATING STAFF ATTITUDES TOWARD SAFETY i

I6 MANAGEMENT SYSTEMS i

I.7 ACCIDENT MANAGEMENT II.

DESIGN II.1 REACTIVITY ACCIDENTS II.2 ACCIDENTS AT LOW. POWER AND WHEN SHUT DOWN h

11.3 MULTIPLE UNIT PROTECTION II.4 FIRES III. CONTAINMENT III.1 BEYGND DBA CAPABILITIES III.2 FILTERED VENTING IV.

EMERGENCY PLANNING IV.1 EPZ SIZE IV.2 MEDICAL SERVICES IV.3 INGE.CTION PATHWAY MEASURES IV.4 DECONTAMINATION AND RELOCATION V.

SEVERE ACCIDENT PHENOMENA V.1 SOURCE TERMS V.2 STEAM EXPLOSIGHS V.3 COMBUSTtBLE GAS VI.

GRAPHITE MODERATED REACTORS

,.,.-,,,,--._._-.___..,__,,,,..._?

--r-_.,

.c a... -... -.... - -

w--

MOST IMPORTANT LESSON THE CHERNOBYL ACCIDENT REMINDS US OF THE CONTINUING IMPORTANCE OF SAFE DESIGN IN BOTH CONCEPT AND IMPLEMENTATIONJ OF OPERATIONAL CONTROLS, OF COMPETENCE AND MOTIVATION OF PLANT MANAGEMENT AND OPERATING STAFF TO OPERATE IN STRICT COMPLIANCE WITH CONTROLSJ AND OF,BACKUPFEATURESOFDEFENSEINDEPTHAGAINSTPOTENTIALACCIDEN[S.

ALTHOUGH A LARGE NUCLEAR POWER PLANT ACCIDENT SOMEWHERE IN 111E U.S. IS UNLIKELY BECAUSE OF DESIGN AND OPERTIONAL FEATURES, WE CANNOT RELAX THE CARE AND VIGILANCE THAT HAVE MADE IT S0.

e e

i f

I

(

t e,-,-.-

e--

,-,,,e

,, -, ~. -, -,, -

v,.,-,,-

,r

e i

OVERAtl CONCLUSION.S REGARDING COMMERCIAL U.S. REACTORS 1.

NO IMMEDIATE REGULATORY ACTION NEEDED:

ACCIDENTS OF THE TYPE OF CHERNOBYL PRECLUDED BY NUCLEAR DESIGN, SHUTDOWN MARGIN, CONTAINMENT, OPERATIONAL CONTROLS.

I ACCIDENT'S LESSONS HAVE BEEN LARGELY ANTICIPATED AND ACCOMMODATED, THOUGH FURTHER CONSIDERATION OF CERTAIN ISSUES IS RECOMMENDED.

2.

REINFORCES SOME ASPECTS OF REQUIREMENTS ALREADY EXISTING CR.

BEING DEVELOPED.

(OPERATIONAL CONTROLS, EMERGENCY PLANNING, CONTAINMENT PERFORMANCE).

J 3.

RESEARCH IN SOME SPECIFIC CHERNOBYL-LESSON AREAS, AS FOUNDA-4 TION FOR SUBSEQUENT CONSIDERATION OF ACTION.

(REACTIVITY ACCIDENTS, ACCIDENTS AT LOW POWER OR SHUT DOWN, SOURCE TERM CHARACTERISTICS).

4.

CHERNOBYL EXPERIENCE WILL REMAIN A CONTINUING PART OF THE BACKGROUND INFORMATION TAKEN INTC ACCOUNT IN A VARIETY OF REACTOR SAFETY AREAS -- tVEN APART FROM ANY ACTIONS THAT MAY BE TAKEN IN DIRECT RESPONSE TO IT.

1 l

i

- -. _ _ -. _ _. _. ~.. _ -. _ _ _.. _.. _ - _ - - _ - _ _. _ _,.. - _....,, _.. - _ _, _... _.. _..

SPECIFIC AREA CO.NCLUSIONS i

I.

0PERATIONS:

' ADMINISTRATIVE CONTROLS BASED ON EXISTING REGULATORY PROVISIONS.ARE GENERALLY ADEQUATE To ASSURE A SAFE CPERATING ENVELOPE.

(PROCEDURAL ADEQUACY AND l

COMPLIANCE, APPROVAL OF TESTS AND UNUSUAL OPERATIONS, BYPASSING OF SAFETY SYSTEMS, ESF AVAILABILITY, OPERATING STAFF ATTITUDES TOWARD SAFETY, MANAGEMENT SYSTEMS, ACCIDENT MANAGEMENT).

REINFORCE ATTENTION TO HUMAN FACTORS:

CONSIDER A HIGH-LEVEL.ON-SITE NUCLEAR SAFETY MANAGER, WITH NO OTHER DUTIES.

CONSIDER A PROGRAM OF PREPAREDNESS FOR ACCIDENT MANAGEMENT.

(TRAINIllG AND PROCEDURES FOR COPING j

WITH SEVERE CORE DAMAGE AND FOR MANAGEMENT OF CONTAINMENT).

j REVIEW ADMINISTRATIVE CCNTROLS TO STP.ENGTHEN i

PROCESS OF TECHNICAL REVIEhS AllD APPROVAL OF CilANGES, TESTS, AND EXPERINENTS.

l REVIEW ESF SAFETY SYSTEM STATUS DISPLAYS AND AVAILABILITY FOR POTENTIAL WORTHWHILE IMPROVEMENTS.

I

9-8 REACTIVITY ACCIDENTS: POSITIVE VOID C0 EFFICIENT 11.1 h8SENT.

BUT SHOULD REVIEW RISKS FROM SPECIFIC SEQUENCES (PRA AND DETERMINISTIC).

II.2 ACCIDENTS AT LOW POWER AND SHUT DCWN: REVIEW, IN VIEW l

OF PRESUMPTION SOMETIMES THAT FULL POWER OPERATION.

LIMITS.

(RECOGNIZE ESF STATUS.)

11.3 MULTIPLE UNIT PROTECTION:

~

ASSESS ADEQUACY WITH " REALISTIC" SOURCE TERMS (VS.

PRESENT ASSESSMENT PER TID-14844).

FOR FUTURE PLANTS, DO NOT SHARE SYSTEMS THAT ARE f

PART OF SHUTDOWN CAPABILITY.

II.4 FIRES: FIRE FIGHTING WITH PADIATION PRESENT: ASSURE ADEQUATE PROVISIONS.

k i

,..,--.-w-,

,,,,7-w_.-,..-,..,y.~,,

-.--w

, ___ _ -, _ _ _ _ ~ _ _. - _. ~. -

..,,,,-..-...,,e,,

111. CONTAINMENT / VENTING: TAKE CHERNOBYL-INTO ACCOUNT IN CURRENT EVALUkTIONOF:

CONTAINMENT PERFORMANCE IN SEVERE ACCIDENTS.

FILTERED VENTING AS A SEVERE ACCIDENT MITIGATION STRATEGY.

IV.

EMERGENCY PLANNING:

NO BASIS FOR CHANGING 10-MILE PLUME EPZ. (INCLUDES CONCEPT OF PROTECTIVE ACTION OUTSIDE IT IF NECESSARY)..

STUDY EFFECT!YENESS OF RELOCATION AND DECONTAMINATION EFFORTS !N U.S.S.R. AND RELATIONSHIP TO U.S.

CAPABILITIES.

(WITH FEMA.)

~

i V.

SEVERE ACCIDENT PHENOMENA:

I RECOGNIZE MECHANICAL DISPERSAL MECHANISMS.

CHEMICAL STRIPPING OF FPS FROM FUEL PARTICLE SURFACE (V!A OXIDATION TO U 0 )

38

- - - -.,.,, -. -.. - ~.

,-v.

VI.

GRAPHITE MODERATED REACTORS (FORT ST. VRAIN HTGR, MODULAR HTGR CONCEPT):

ENO DIRECT ASSOCIATION WITH DESIGN WEAXNESSES THAT CONTRIBUTED TO CHERNOBYL ACCIDENT (HTGRS HAVE HELIUM COOLANT,. CERAMIC CORE,: NEGATIVE OVERALL REACTIVITY COEFFICIENT, DIVERSE ALTERNATE SHUTDOWN AND C00L!t!G SYSTEMS).

No NEW CONCERNS RE HTGR SEVERE ACCIDENT PHENOMENA, BUT REINFORCED DESIRABILITY OF:

TARGETED PRA GRAPHITE THERMAL STRESS EXPERIMENTS 1

I

..n.,,

,,,,--..n,

,e e'

RECOMMENDATIONS THAT THE COMMISSION:

APPROVE THE IMPLICATIONS REPORT FOR PUBLICATION FOR COMMENT.

NOTE THAT THE STAFF:

WILL NOTICE AVAILABILITY OF'THE FACT-FINDING AND IMPLICATIONS REPORTS IN THE FEDERAL REGISTER WILL PREPARE PROGRAM TO COMPLETE ALL FURTHER STUDIES INDICATED.

EXPECTS PROGRAM COMPLETI0fl WITHIN ONE YEAR. -

WILL CONTINUE TO COORDINATE WITH ANY ONGOING INTER-

~

NATIONAL EFFORTS.

WILL CONTINUE TO MONITOR FOR NEW INFORMATION CONCERNING LHERNOBYL (E.G., IAEA FOLLOWUP EFFORTS) AND WILL INFORM COMMISSION OF ANY SIGNIFICANT NEW INFORMATION.

INTENDS TO ISSUE FINAL FACT-FINDING AND IMPLICATIONS REPORTS FOLLOWING APPROPRIATE INCOPPORATION OF PUBLIC COMMENTS.

l O

0

---.c,....

-,,,,----,-,,,--n,m._,

-,-----,--,,r.

.,---,w-,,

, + -. -

--w.,.

j----

--...........uu un m r v er nwn:vywwwwwwygy, g l

.I g;

TRAMSMITTAL T0:

V Docu'nent Control Desk, 016 Phillips Il L

fs

!1

'si ADVANCED COPY TO:

The Public Document Room j

3:

I 1

DATE:

}

l k

'h 33 E

33 FROM:

SECY (,orrespondence & Records Branch F.

3 3:

g, 3:

3 Attached are copies of a Commission meeting transcript and related meeting

{'

3 i,

' document (s). They are being forwarded for entry on the Daily Accession List and j i' placement in the Public Document Room. No other distribution is requested or ll

.a required.

Meeting

Title:

30MkshA 00 b Oobt 3 ll.

.)

3' 3

9 3

5 i Meeting Date:

1 (o

Rl Open X

Closed k'

3 ;

9 5 !

!b 3

$R' 3 !

Item Description *:

Copies 3

Advanced DCS 5 i to PDR Cg

8 3

3 :

3 h

1. TRANSCRIPT 1

1 3 :

g i w/ n,Lm con i

3 :

i 9

3 3!

3

$ f

2. 3 C.c.a.A 27 -14 1

l h!

3 :

!E

S

s

3. Nwft a-l >_ En

)

k:s a

l l

2l 3

3 ".

4.

333 3 ll R

3 5

33 3=l 3i:

5.l 6.

i 33 3 ""

33 i

PDR is advanced one copy of each document, two of each SECY paper.

3 :

C&R Branch files the original transcript, with attachments, without SECY j l papers.

3 !

3 J

~

ML20210T885

Contents

Text

Title:

SUMMARY

Title:

Navigation menu

ML20210T885

Text

Title:

SUMMARY

Title:

Navigation menu

Search