ML19309G931

Transcript of 800421 Briefing in Washington,Dc Re B&W Reactor Response & Vulnerability Task Force.Pp 1-66

ML19309G931
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Issue date:	04/21/1980
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REF-10CFR9.7 NUDOCS 8005080015
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U N ITE D STATES N U CLE AR R EG UL ATO RY COMMISSION in the matter of:

BRIEFING ON BABCOCK AND WILCOX REACTOR RESPONSE AND VULNERABILITY TASK FORCE j

Piace:

Washington, D. C.

Date:

April 21, 1980 Pages:

1 - 66 INTMNAWONAL VEmaAnM RzPonntas. INC.

m SOUTH CAPITOL STMET. S. W. SUITE 107 WASHINGTON. D. C. 20002 2nz -

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UNITED STATES OF AMERICA i

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2 NUCLEAR REGULATORY COMMISSION l

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_____________________________________x i

e In the Matter of:

i 6

BRIEFING ON B&W REACTOR I

7 i RESPONSE AND VULNERABILITY l

i TASK FORCE 9

---

X 10 i

11 Commissioners' Conference Room 1

1-1717 H Street, N.W.

Washington, D.C.

13 Monday, April 21, 1980 i

14 i

I l

is l

The Commission met, pursuant to notice, for i

16 I

l presentation of the above-entitled matter, at 2:05 p.m.,

17 l John F. Ahearne, Chairman of the Commission, presiding.

18

! BEFORE:

i 19 l

VICTOR GILINSKY, Commissioner I

i PETER A. BRADFORD, Commissioner g

l JOSEPH HENDRIE, Commissioner i,

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CHAIRMAN AHEARNE:

Harold?

The main purpose of meetin 2

! today is to hear from the task force that the director of the I

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office of Nuclear Reactor regulation established following the l Crystal River episode to address B&W reactor response and vul-3 nerability.

Over..the past. year plus we 've had a number of task 6

forces, efforts which have looked at various aspects of this I

l issue and at some stage this afternoon, I'm sure we'll be covering 3

many of those points.

And as I recall, this includes the fact 9

that Crystal River itself has been called out for s,pecial review IO of the sensitivity on the standpoint that it was used as repre-II sentative of B&W plants and you had underway, I guess working i

through research a review of the sensitivity of B&W plants per l

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i se.

So we are here to hear from you.

i Id I

MR. DENTON:

Thank you.

I have the chairman...and U

l cochairman of that task force with me, Bob T desco and Tom Novak I

I M

I did appoint this task force after the Crystal River event of l

t' l February 26.

At the time I did it I was also thinking about t

4 I

- the Oconee event which had h'appened later last year.

Reraising II i the question of why in just less than 40 reactor years B&W plands

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had so many undesirable incidents, involving loss of feedwater.

• 1 i And we were beginning to recognize that they were sensitive not i only to loss of auxiliary feedwater leading to undercooling butj i

i

! also the incidents that had overcooling by getting too much-i

• 1 water in the steam generator.

So I asked Bob to head up a taskj

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' force to give me an assessment of the acceptability of continued L_

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I operations and any recommendations that he might develop to i supplement those that were in the action plan as applying to all l reactors and to single out B&W's as a class and look just hard A

at their sensitivity of feedwater transients in light of every-J

! thing that we had learned including the information from the t

6 l IREP program and any other sources.

So with that introduction i

7

! let me turn it over to Bob.

What we are giving today is a statu s 1

I 3

report.

Bob's recommmendations are still under review by the i

9 ACRS and are still undergoing some internal review but I did

]

i 10 want you to hear where the task force has come out.

I 11 i

MR. TEDESCO:

Thank you. Harold.

I'd like to have the

.I 12 i first slide which is kind of an introduction to where we are 13 l on the task force.that Harold started.

I think.he next slide-i 1

14 i should give us a little background of where we are.

This j

l was established with a specific charter to give us some short l

14 term assessment on the B&W reactors considering their recent I

17, I

i operating history, namely Crystal River and the Oconee event i

18

! and just see why we are getting this response now.

And that we 19 were to consider and recommend additional requirements that mayj l

20 l arise as a result of our review. We designed our review of the 1

21 l three principal areas: 1) to deal with the sensitivity of the O

l response, not only to but a recovering from.the over ing andl t

C l under'

.ing transients.

considerations toward the i

Id Crystal River event when dealing with our f amous integrated 2

control systems and a nonnuclear instrumentation.

And as a l

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vom.m.numw.m =.

e = camen.smer.s,e awr e

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3 peor.w i

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,l j background to really ask ourselves some very hard questions.

i I

j If we are having these events and they are reoccurring, what l

is the effectiveness of all the actions that we have taken 4

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'since TMI considering our belletins and orders and our li-I i

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censing efforts.

So we wanted to kind of give ourselves a per'-

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spective of our approach toward stabilizing the transients and 7

iasking ourselves are we on the right track or is there more s

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i that should be done? May-I have the next slide please?

The 9

i resultsofourreviewwhichpresentlyconstitutethedraftref 10 l port 667 titled The Transient Response of the B&W Reactors.

11 l

j We released it as a draft to division directors as well as to; i

12 l

l l the B&W owners, the ACRS on April 2 of this year.

The report!

13 s

1 i

l did not contain section 7, which was part of a workdown.

14 i

i i

! Section 7 addressed in a semi-quantitative way an approach l

16

- toward assessing the effectiveness of the 20 some recommenda-l i

tions that we had made.

When we come up with a list of action t

g j the question was raised by Mrs.

the assistant direc-1 l tors, that gee whiz if we take all these items how do we 39 I

g really know what we are buying off on. Are we really improvinU 1

21 l our safety and if we are, by what amount?

Well with that as i

l the direction of the charter we went ahead with the risk I

i l assessment staff and asked if they couldn't help us put a l

34

! definition or some way of assessing the effectiveness of these U

items?

Now then we are prepared, a draft was written this i

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! weekend and we've had our first discussions this morning.

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! There's hope that we have for the expectation to complE.te l

2 I that section sometime this week.

The report and its contents

. have been discussed with the ACRS, at both the first subcom-i i

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i mittee and the first full committee meeting earlier this month.

i j renewal, well...our second meeting with the owners will be 7

![ held Wednesday of this week.

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~ I thought that you. missed the meeting CHMN. AHEARNE:

9 I of the ACRS?

10 MR. TEDESCO:

No we had a subcommittee meeting and

• 11

a full committee one.

Now we are going back again on the 29th i

12 i

I and also the full committee in May.

We are very anxious to I

13 get the committee's input into our recommendations.

The 1s i

I next slide is over very quickly, listing the members of the i

13 task force.

The main point that we've brought out here is 16 i

that we are an interdisciplinary group and not only inter-l I,<

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i disciplinary but interoffice still so we have taken a broad is i

I cross section of our capabilities to direct our efforts on 19 i

i this short term effort that we have.

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l CHMN. AHEARNE:

Anderson is what kind of a guy?

l 21

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MR. TEDESCO:

He's the ISC man.

He has helped with'

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n integrated control systems.

He has worked before with us on

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the B&W system.

He really.is helping us quite a bit.

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i MR. DENTON:

I think we have a technical assistance f

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l this area, perhaps as many as 10 I believe which help us in s

the routine case work.

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I MR. TEDESCO:

Now the general of the next point i

3 I was in fourth place that we,. paper have to be nothing new but 6

in a more confirmatory way, we have again seen the same as-I I

,! pects.

The B&W design manifests a more responsiveness to the 7

S I secondary site than the others..The other way to. treat this 9

principally is through the one steam generator and the inte-i 10 l grated control system.

Our review again has shown us that 11 i

generator design is technically sound but because of a small I

! capability to serve as a heat sink, does not require a high 13 interactive responses to tropism.

There is a high degree of 14 i

l overall plant interaction that in the control system, l'

in the generator.

Also the design of the plant and its response 16 i

to transient

, established that the operators are re-l 17 i

, quired to take a more rapid action to have a better understan'd-18 l

l ing of the instrumentation and the response of the plant that 19 l

l one might say for other BWR plants.

20 i

CHMN. AHEARNE:

There was a statement and I wonder 21 if you could expand on it?

It had to do with steam generator;..

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I I'm not sure it's the right place to raise the question.

i If..its the wrong place, just tell me.

Would you say that 4

replacement of the Oster steam generator does not appear to I i

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l be practical or a necessary reaction especially as a way to

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! get certain other safety advantages.

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l MR. TEDESCO:

As far as the aspects of a plant that I

! is operating...I didn ' t realize that there was very practical d

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I l difficulty, i

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No I was focussed more on what w CHMN. AHEARNE:

7

{ the safety MR. TEDESCO:

'O.K. The safety things that we have 1

9 I

seen, is that even though you have a small wall inventory 10 that creates a responsive characteristic if you tell me what e

11 l that insert pipe steam might break, you may reach the inven 1:

! tory, the toxic wastes would be less-. So on one hand you IU i have a benefit in that regard as well as the reestablishment 14 i

i

! of these things.

And here you need less water to reestablishI 13 I

I these things.

I 14 I

i MR. DENTON:

You may recall the ACRS provided their' 17 comments on the question of B&W plants under construction.

It j

I COMM. HENDRIE:

There is also the safety related 19 I

aspect that unlike the U-tube steam generators of the other 40

.i 21 two vendors where you come into a plenum with the bottom of i

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the steam generator, the primary fluid does and it goes up l

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l through a closed U-tube then down to a plenum at the bottom i

l of the gap, you get gas generation in the steam generator.

4 3

You get it up in those U-tubes.

You struggle with that prob '

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j lem and it probably won't happen enough to obscure all---

I' to prevent all cooling.

But there is clearly no good way to i vent some thousands of U-tubes inside steam generators.

So I

l that whereas the B&W design, primary fluid comes in.at the top l 3

l l to a plenum, goes straight down through the tubes and out the I bottom and you now have a perfectly obvious vent point at the';

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7 top of that primary pipe which goes up, bends over and comes s

! into the top of the steam generator.

And on the B&W machine, 9

you are in fact in a position to vent non-condensable gases 10 or even if you want to do tubes and steam, if you've got some i

i 11 steam binding in the system, by putting the vent on those l

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l places and you know it's a very clearcut proposition.

So youl i

know there are some aspects to this design that....

U Id COMM. BRADFORD:

Are there vents there now Joe or is l'e l

that for something..

COMM. HENDRIE:

That's one of the...back in the 17 l lessons learned days...that was one of the things that Harold 18 l

l decided...I guess his task force hasn't quite felt as strongly 19 I

8 as he did...but I think he decided if he ever got sent to 20 l another site he wanted to have some vents in place remotely 21 controllable so that he could order the vents open and not go' I

3 l

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through another set of hydrogen bubble matters.

As a matter of fact on the B&W plants, there is a possibility of that.

24 They are referred to as a candy cane.

Venting at the top of l 2

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also required because those things are probably pretty good 2

l up there.

On the other piece you are going to have to vent i

2 lon the vessel head..

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MR. TEDESCO:

Take the next slide please.

Talking 4

i l about.... generally talking about the recommendations. Here we i

5

' have a purpose.

We wanted.to minimize the frequency and conse-1 I

quences of nuclearization.... instrumentation and control systems wefocusedheavilyinourtaskforceeffortstogiveacontin!

3 l

ued assurance of the. availability to do things. We really felt to that if we keep that heat sink available it will go a long ways i

11 l toward mitigating the consequences of transient and thirdly, i

12 l' it proved our plant recovery capability from the transient.

13 What we are finding more and more is that if we can maintain la i

l the heat sink, we con't have to go into this undercooling and !

l' overcooling event that the situation that challenge unduly l

14 the engineer.. case decision.

transient and rise

7 l

t

' through it, reactor protection systems and not go beyond that la l

l point.

When you start to go.into a near postactive recovery 19 l

l mode.

So we had focused heavily upon that heat sink.

The 20 t

areas that we looked at are listed here are 2reeboiler systems, 21 l

the bnplementation control, certain design and operational j

y 3 matters and general areas of improvment assuming a long term l

i approach.

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MR. DENTON:

Our mission...Let me point out Bob, 3

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. ase surren sumr FrumeT. t w. marrt set l

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l turned out to have been a more complex issue than I first l

l i realized and that I thought perhaps a brute force way of get-l ting water into that steam generator under all conditions in 4

an assured manner would be a solution to compensate for the i

I lack of inventory in the steam generator.

That has its prob-i 3

1 ems, as Bob can tell you.

Because then it produces the l

6 i

7 overcooling transients, perhaps overfilling the steam genera-l 8

I tor too fast.

This desi.gn does present a unique problem, I

' in both you've got to get water in faster than in other plants IO and at the same time it's such a small volume, you can't get 11 j too much water in it.

So you have to control it within a l

1 much narrower bounds than with a steam generator that has 13 a large thermal capacity and large volume that can tolerate i

l 14 i

l loss of fuel transients.

13 j

COME. BRADFORD:

What is the concern in overcooling' 16 I

now?

What happens?

i 17 i

MR. TEDESCO:

When you start to shrink down and la start reducing the volume in your primary systems,1) you l

l l

start losing the level and the pressurizers and 2) you create 20 the potential for flooding in your system.

COMM. HENDRIE:

The rapid cooling of the water in j i

f the primary system entraps and then the level of the press-l l

i urizer falls and unless the heater grating is--which it isn't;

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i for this kind of fastmoving transient--is really enormous 3

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! you can't boil enough water up in the pressurizer to keep i

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the precsure high in that steambubble.

The pressure just 3

falls.

The pressure f alls then you may actually, you know j if its severe enough, I think the projections are that you I

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don't go below saturation on the kind of overflowing transients i

6 j we've seen or expect, but at least there's that potential.

7

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l You do drop the level and you drop the level out of the ob-3 servable range in the pressurizer so you can't see it anymore 9

which is pretty annoying and on.most of these--on a good over-li 10 cooling transient you do drop the pressure at least f ar enough 11 i

l to trigger the high pressure injection.

And that's the typi-12 l cal way to get into these sequences where the high pressure 13 i

is injection pumps are. triggered.

The rules after Three Mile 14 i

i i

are don't tinker wi'.h the ejection so it's allowed to go.

II 14 It refuels the system.

Comesolidandthenwehavewateronl i

the floor of the building.

So the overcooling isn't a great l problem.

There are some...let's see all of the plants we've i

j got..All operating B&W plants are I forget the designation...

3, 1

I

.g but there are those walkthroughs with the offspeed up high.

i l

21 MR. NOVAK: Yes. The offspeed water is high anu l

it 's the 177.

1 COMM. HENDRIE:

The 177. So that when you put the..

start the offspeed in...why it's spraying it up high over these 24 1

l'.

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hot tubes and avoided shell and the heat transfer rate is teregneavemen6 VeumsfMs AmmunguL lac, 4

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1 lprobablyenormous.

There are...I believe the 205...

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MR. NOVAK:

They feed from the bottom.

j COMM. HENDRIE:

Would feed from the bottom so that Ij ou were just grazing a liquid level in the shell and that y

a i

3

!would have I think, I think that's a change in the right t

fdirection.

I daink those generators as they come in would 6

l 7

l have a substantially smaller sensitivity to overcooling.

I i

8 I That is what Harold said,- just dry water in the of fspeed waterj l

9 and the exchanger, I think you can do it with the 205s but a j

10 concern about an overcooling transient that was severe enough 11 i to be_a problem.

12 MR. DENTON:

Tha't's one of the recommendations that Bob has.

COMM. HENDRIE:

Yeah I noted that a suggestion was p~

i j to take a look at what the practicality was for a low injection.

16 MR. DENTON:

In the absence of any guide the objective l

17 I wanted Bob to shoot for is to make the transient zesponse tQ 18 l

! these the sane as other PWRs in the sensc that we've had lots 19 l of reactor years of tr:se and have had very little of these 20

! Crystal River type--overcooling or undercooling events there--

21 and we won't know how close Bob has gotten until the risk as-;

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l sessment is completed, which is now underway.

And what he has l recommended are all the things that people can think of, sort;

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o' short of replacing the steam generator or the pressurizer l s

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l CHMN. AHEARNE:

I assume that what he's recommended i

is all the things that people can think of properly scrutinized.

4 1

MR. DENTON: Yes.

Well properly within our resources a

~

because now we are being scrutinized by others.

6 MR. TEDESCO:

The last item on this slide deals with' 7

the different quotations.

We had originally thought that I

j perhaps we could take some recommendations.

That after we 9

had thef t about a mystery perhaps that could have entered the '

l to task action plan.

Now we are moving toward closure on the 11 i plan and I'm sure that we won't be dealing with lessons learned I:

i and what's happened.

So we've need recommendations 13 i

! separately from the plan continuing on the prioritization and 14 i

' resources as we move along.

l 13 I

MR. DENTON:

I would not intend to hold these re-i id action plans.

I hope to lock the action plan up as being thel I.

l results of investigations that have been underway and this f

g i

will get incorporated into our own office program plan along g,,

20 with what other lessons come along.

21 j

CHMN. AHEARNE:

Well let's see what that means.

MR. DENTON:

It means that after we've come to I

n

, agreement on what to do we will implement it within the office l i

24 but not...I want to finish the action plan as being our re

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CHMN. AHEARNE:

No my question is more as a sense 2

j of the resources that you have to apply.

Because I understand!

i l that one of the things that the final stage of going through I the action plan which will be coming to us I guez, at the end 4

i of this month will be here's how the resources across the fagencywillbereadjusted.

Nowlet'usproposetosupposethat!

6 l

j the Commission agrees or modifies it and reaches a conclusion 7

i 8

! on here's now the new set of resources across the agency.

In l

9 I the absence of this being incorperated into it, what does that 10 end up meaning? That you will then have to readjust the re '

II j sources within NRR.

I l

i MR. DENTON:

Yes.

l 1s CHMN. AHEARNE:

But it doesn't mean that you wouldn't i

14 i

) do this?

13 MR. DENTON:

Yes.

That's right.

It.would.

.But 16 this would have to be factored in with whatever the competing' 17 I

priorities were at that time.

I think Bob estimates imple-It mentation of all there items on our part would take about 5 l

i man years.

We don't have 5 man years.

We're strained now, 20 l

but I set that decision aside waiting the results of the 21 review of these recommendations.

Because we are always going l

to be having new demands that we will have to program around.

l Since Tom is assuming the role of the supervising all the

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operating reactors as his first chore, I'll get him a job

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i i of finding a way to do this job efficiently less impact.

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MR. TEDESCO:

The next half a dozen slides will 3

go int.o all the that we!v.e rung up and the numbers I N,._

4 think have pretty well been handled within the context of the 1

3 I task action plan so what we thought we would do is take maybe I

6 about five of them and highlight them for yga and represent I

j some new aspects of it.

Then ws*11 go into each one.and 8

if you have any questions on this we can respond to them.

9 We'd like to kind.of highlight them more significantly.

10 COMM. GILINSKY:

Before you do that.

You may have 11

! covered this and if you did I apologize, but what is it that I understand that on the l 1:

caused you to rethink the problem?

13 Crystal River event you played a role in this but what did la i

l that do for you that previous experience.

15 MR. DENTON:

I think it's just the accumu---There i

l 16

.i was the Oconee event in which they'd lost..some. indications

! in November.

But I think recognition on my part that even 18 l

though Crystal River accident did not directly represent i

a public health and safety threat.

Just the amount of atten-

,0 4

tion that the public gets and has to give to such events and 1

4 that we have to give to such events...maybe I should rethink i 7

my threshold, but putting that much water in the basement of 4

containment even though this doesn't represent in any way j

i 3

core damage there's something we should avoid.

And here's i

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l l another instance where its a.B&W plant performing in a manner,

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completely unheard of in some of the other PWR designs for

! a relatively innocuous beginning transients.

Its just the

fact that its -- doesn't have the sluggishness to take the I

i l

ups and downs of the feedwater system.

I guess we also learn-i i

6 i

i ed that our order to B&W plants which was to enable manual ac I 7

- tion on.the ICS and to have automatic initiation of auxiliary l

8 I

feedwater whenever the main feedwater system was lost didn't 9

3 quite work in this case because the main feedwater was never l

l quite lost.

It ramped down to a very low rate so therefore, J

11

)

j it shows that there are some further changes that fulcrums =and i

g 1

I

! waters and lesssons learned didn't fully address the actual D

l l cvents at Crystal River.

I guess I just don't think in the 14 long 30 year time span for B&W plants we ought to face Crystal.

u Rivers or Oconees or some of these other kinds of events as nearly as of ten as we've been facing them in the past.

1.,

I COMM. GILINSKY:

The other day when we were down -

j l

at the ACRS, Hal Lewis, he thought Crystal River was more

'l 39 l

i important than, I can't remember whether he may have been 3

21 upset through ---

j j

CHMN., AHEARNE:

I wouldn't want to quote him.

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l COMM. GILINSKY:

I wouldn't want to quote him f

f either but he said, he made it sound, it was pretty.important, 24 I

"J to him.

Do you have any discussions with...I assume you've 1

1 i

sem venaams stupeersus lac.

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! talked to the ACS.

i l

2 1

MR. NOVAK:

I think one of his observations was I with regard to the f act that the safety injection systems i

l came on and you were pumping water through the safety valves 4

I I and that the potential then of not being able to isolate a i

e loss of coolant accident.

That's one comparison that I could!

l l make between that and Three Mile where you always had the 7

l 8

potential of isolating the leak at Three Mile Island but it l

9 j took a while to do it.

But I think we share his concern, that 1

IO j pumping water up through the safety valves today with the un-i derstanding that we have on their closing ability is a concer that I think we share.

I think..it wouldn't surprise us l

i that they leak at 2200 pounds.

But you are not going to stay 1s

! at 2200 pounds.

You are going to come down.

And I think the{

3 s

j spring loaded valves will probably effectively isolate most 16 kinds of leaks unless it really stuck open and then you've got 17 yourself with a loss of coolant accident that you've really is created through the system that was there to protect against 19 l

the locus.

20 COMM. GILINSKY:

Well I think that's 21 COMM. HENDRIE:

In part one leads into that situati,on i

by virtue of the provisions that we've felt it appropriate i

to ask these plants to implement and then procedures to use g

f after Three Mile Island.

Although I think you ought to be i

2 I

i 1

8 larTsenah Velumanas RapansrTWut last l

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l sort of f air to ourselves, I think we al-1 recognize that longer f term studies in optimization of that situation ware indicated I

! and that you know, the things we said right after Three Mile I

now let's do the following things.

I mean B&W plants to cut l

f i

down the rate of challenge to their release and so on were i

- appropriately sealed in the short term but I don't think I

j I

l 7

J j any of us believe that was a great permanent solution. And 3

! this just reinforces the' point of view, well go ahead and 9

look further and see if we.can find a better way so that we 10 l

\\

don't compel --drive with the safeties open everytime you i

11 get the UPI tripped.

I l

i MR. DENTON:

Bob will come to some criteria for 13

the design of feedwater systems.

We haven't had in the past.

I#

1 In the past our criteria have been to prevent fuel damage.

j te i

i That's a little different than saying don't put 50,000 gallon's 16 I

of water through the safety valves.

And I think we need to 1,,

i take a broader view of safety than just preventing fuel damag'e.

l l

. COMM. GILINSKY: Are you saying that the problem that 19 l

we are dealing with here is coping with rather lesser but 1

,.0 21 undesirable consequences or is this review something about f

the system that in f act does cause you to be concerned about i l

i fuel damage.

That's sort of the way I took Al Lewis's com-I f

ment.

He really was concerned about it and he's a guy who

4 i

doesn't get concerned...

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l MR. DENTON:

Well, I guess that I interacted with l

him directly to no source of his concern.

l j

MR. HANRAHAN:

There was a lot of concern about the 4

l PORV and so the set points were sort of hired to challenge I

i i

I e~

I those of ten and if we are getting the safeties challenged.

i 6

iNow the PORV can be blocked off where the safeties can't.

7 i

MR. DENTON:

This will come clearer to I think as I

8 l you see the kinds of things that Bob recommended.

Obviously 9

protecting the reactor from secondary system disturbances you 10

would ideally have a very large steam generator.

That way 11 l you could act with impunity to losses of the normal 1,.

I feedwater coming in.

You'd have lots of time for operator 13 action.

And this system does place a lot of demands and I i

! guess what I'm still trying to get an answer on...to answer,

! the chairman's question... is in the absence of this large l

g i

capacity, are there other things in the way of control systems g.

l and feedwater systems and operator training procedures that jg l

19 I can compensate for the lack of thermal inventory in the systems.

i l

i go COMM. GILINSKY: If I could just make one last com-i 21 ment, I thought I heard Al say that he felt we were under-

=

j reacting in Crystal River.

O l

CHMN. AHEARNE:

Yes.

24 l

COMM. GILINSKY:

Compared to other I

I CHMN. AHEARNE: Yes. But of course he hadn't seen i

(

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19 cacz sc

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8 2

COMM. GILINSKY:

Right.

i I

CHMN AHEARNE:

Was he at...

l 4

l COMM. GILINSKY:

I don't mean to say that this is an underreaction but at least...

I 6

MR. TEDESCO:

He walked in and walked out during 7

presentation but I don't think he was there for any length i

i I

of time.

I I

COMM. GILINSKY:

Maybe the part he saw was CHMN. AHEARNE:

He didn't get to this part.

f COMM. GILINSKY:

No, No.

I didn't mean to say l

t-CHMN. AHEARNE:

But he has...he had said that.

j 13 4

That's right.

j u

i COMM. GILINSKY:

But he took it as a pretty serious:

13 j event and I wouldn't that it was just because he was worried j M

\\

about some water spilling on the floor.

j 17 l

MR. DENTON:

He was not a member of the subcommittep 18 I

i e

i either.

j I

MR. TEDESCO:

No. No.

20 t

COMM. GILINSKY:

Well, you might want to talk to 21 l

him.

j i

MR. TEDESCO:

Well going back what we'd thought f

4-i t

we'd do was highlight a few of the items to give you a full l

3 3

insight to where we are.

And the other ones that we feel have I

i n

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I

20 caer.wc I

i l been somewhat or maybe to a certain extent in our j

l l

t i

i 7

l staff action plan and other actions by bulletins and others.

If you want to stop me anymore please do so.

i

, The first area that deals with the auxiliary feedwater system.

l 4

1 3

iUp to now the feedwater systems on the B&W plants have not i

6

' really been signficant as I require it to put them in a situa-;

j l tion where you might want to say that they are engineered.

7 I

l safety features.

They've been included in the plants in the

)

8 l

i 9

sense that they are nonnuclear or non-safety equipment, i

l IO

yet highly interactive in their operation.

We have files from i

e j

11

! our experience that adverse effec.ts and conservative actions I

3' l have caused malfunctions of the water system.

So that 13 the actions that we are recommending are ones to upgrade the 14 f auxiliary feedwater system to an engineer safety feature.

{

13

And that would address questions like single failure protectiop, 16 I

l reliability, the arrangement of power supplies, and would cer-17 l

l

! tainly address the issue of whether or not these systems have' 18 l

l to be designed to withstand earthquake requirements.

It will I

19 l also address the other matters like the high energy line 20 I

I break.

21 COMM. GILINSKY:

Can I ask you Bob, Bob, why C

i f didn't we reach these conclusions when we took a look at this I

i i

problem last May.

4 4

l MR. TEDESCO:

Well we started looking at this h

im?iesnae. Veumatus 8tsper,wus 84

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i

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pasc.we 21 I

I situation on the task force.

We did open up the r

I

question of the auxiliary feedwater systems.

And a part of 2

I the requirement that we have established they are orders that I

s i

the Commission issues-- was that the operators wouldn't be i

e~

able to operate the auxiliary feedwater system independent of, i

6 l the integrated control system.

But this would be a manual 7

j capability.

Since that time we 've gone.through Oconee and i

8 l

Crystal River and we fee 1 like we have to take a little more 9

. action right now and therefore we want to remove this system to l

completely from the control system and give it the proper i

11 j

capability that it will be an engineering safety feature.

12 I

l That it will be independent of any failures in the nonnuclear!

13 I

I l

instrumentation and the integrated control systems.

MR. NOVAK:

I think the order had two parts to it.

l There was a short term part which more or less said at least if you have an event the operator was capable of responding.

g 3,

l Second, we had a long term part of the order which all the I

l j,

j plants are still under which said there should be work done i

i 20 to see what improvements can be made in.the auxiliary feedwader

)

l l

21 l

system which I in turn, I view this: How can you make it a l

9 1

l

=

l more reliable system.

Now the B&W owners have since that i

22 time done reliability analysis to identify the weak links of, i

i i

l 2d the systems.

That work is ongoing right now.

We. view this-'

2 I view this as really a just pointing out that let's try to,

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l lbecomemorespecifictodayonwhatweshouldbedoinginterms I

i

of the long term requirements to the auxiliary feedwater syste'm.

1 1' In a way its almost going back to our old way of doing busi-a jness.

We don't have a reliability goal in mind for the e

t! auxiliary feedwater system that we can set.

But we do know

~

6 i

that if you have a system that you treat as a safety grade 7

! system, that it's going to be designed properly, it's going I

to have the right kind of equipment and it will be operated 9

I in a more attentive manner.

I think that's the thrust of 10 l what I see when we go after an engineered safety feature.

11 l

MR. DENTON:

One and two provide the umbrella.

I:

l l

The whole thrust of the bulletins and orders efforts last 13 year...the thrust was increased to the liability of these systems without necessarily calling it an engineering safety l t.

l feature.

Now by going all the way and calling it an engineer' 16 I

ing safety feature, sweeps in a few other requirements on the r

l i system that were different than the considerations you had.

3, I

last summer toward increasing reliability in normal operations.

39 i

I 20 These seismic requirements or other high energy line breaks 21 all go to protecting this. system against other less lively threats than loss of feedwater.

l COMM. GILINSKY:

I guess what I'm driving at here 2d

! is does this reflect a better understanding of the problem or; 3

l are we in effect reacting to all the publicity that these l

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jproblems have threatened.

i MR. DENTON:

I don't think I would -- Well.

l MR. NOVAK:

I think it is better understanding 4

ll from the point of view that for example, the order said that 3

i

,. the auxiliary feedwater system should be started if you trip 6

i j both feedwater pumps.

So there was a signal which initiated 7

! the auxiliary feedwater system itself. What we've seen now 8

by looking at the operating experience more carefully is that 9

! that signal alone is not enough to initiate the auxiliary 10 i feedwater system when it's needed.

So I think from the point!

11 I

j of view of saying let's be more sophisticated.

Let's make thel 1:

i designer take the time to identify that specific parameter 1.1 that should initiate auxiliary feedwater system.

Let's not j

Id i

i be that mechanistic that you only need auxiliary feedwater l

33 l when you trip main feedwater.

But I think its looking at the g

I

7 problem perhaps in a more sophisticated way and giving the ja l designer a tougher job to handle.

l 19 COMM. GILINSKY:

Let's see now. Why is that not I

20 sufficient?

21 l

MR. NOVAK:

Because in the Crystal River situation..

i the pumps ran back but they did not trip off.

1 l

MR. DENTON:

So they really weren't putting feedwat' r e

I 1

.d i

in but they hadn't quite stopped running either.

They weren't l

1 And you should have had a more direct signal j

putting much in..

i i

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I than...we were acting as though complete loss of feedwater..

the feedwater was a black or white situation instead of being 9

l shades of gray.

I think also..we 're trying.;to react to the 1

• recommendations that say be more alert to operating problems i

I

~

.' and stop and learn the lessons from each one.

And so you 6

i stop and you look into this in more detail than you might I

7 j have a couple of years back and see what we can extract from 8

i it.

I guess I look upon safety as not being a plateau but as a continuous learning experience and I would guess in the 10 j

next few years we will have other kinds of events where we 11 f.

will ask ourselves why didn't we do it two years ago but we 1_.

l l

just didn' t understand the entire process that well so...

13 l

I COMM. HENDRIE:

I think if we had treated Davis l

I#

i Besse in this fashion, we would have not enjoyed the events l

13 of the last 14 months.

VOICE:

Well I think that's one of the comments l.

e l

Hal Lewis was making.

I don't know if it's the specific one g

l 39 i

but I recall reading at least something he said which sugges-l 20 l

ted that he was concerned that the sensitivity of the plant 21 to a single failure in a non safety grade part of the system f

l resulted in Crystal Rive.- III.

That was his concern as I I

l i

see it.

That these plants -.. dais plant design...if its that I

24 sensitive to a single failurs in a nonsafety grade system re' i

2 sulting in the event that caused him concern.

They'll never 4

IwTwenafienien. Vennette EterestunuL last

.ewr w,

evamme.s...

m.e a c s-m

4 25 I

nez.we.

I I

i l get out all the single failures in nonsafety grade systems.

j I

i l You'll have to accept them.

So I think that's the thrust of f

1'.ql our approach here.

COMM. GILINSKY:

Well that's right.

I went down 1

l

=

~

there and took a look at it and if you lo6k at these: tiny 6

little prongs and I understand that these two little things 7

8 touching produces a sequence of dominoes falling and 40,000 S

} gallons of water on the floor.

It's a sobering thought.

9 i

MR. TEDESCO:

And you know you have to realize 10

, that when you deal with control systems they are not i

11

! against single failures.

When they fail, they fail. And they.

1*

i just start the And clearly what you want 13 to do is remove those pieces of equipment that are essential i

i for plant recovery.

And we feel the auxiliary feedwater sys !

15

!i I tem clearly is needed in a very real way because of its heat i 14 l.

sink.

to give it the proper attention that i

l it deserves g

CHMN. AHEARNE:

If I could get back to a point that 39 I

20 Vic was raising.

I'm puzzled by the last prong.

We had a l

21 l series of discussions, Harold with you on the sensitivity of l

=

the B&W reaccors and addressing the question of is the designl j

l l

2 l

so sensitive to transients that changes ought to be made and l

24 at the time your conclusion was reached.

It is not subject i

l 15 to any convict quick review.

That-..it.. required instead this i

i I

8 langennah Vemmattes Rementgut 14 l

3

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26 l

y P AGE NC 6

1 i

l I

3-6 month review, Iguessifyoucountthefirsthydroplant,j I

and in fact, in January, you pointed out that it was still l fairly too early to reach a conclusion that had to wait through 9-a

' the review of the IREP study.

Now, however, you have some I

I list of 18 and 20 recommendations based upon this task force !

i 6

j I guess I am kind of puzzled as the sort of same similar 7

j thrust of Vic's question of how are you sure this is now the S

l right set. It almost sounds like either the IREP review has 9

. now been overtaken ay this or this ought to wait until later, 10 l I'm not sure why.

11 l

MR. DENTON:==I-guess I' don't maybe haven't articu 12 l

1 lated the interrelationship; of all these studies, but I was I3 intended to assess the total risk of B&W plants visa vee i

other manufacturers designs.

Not only against feedwater i

13 upsets but recognizing that when you change the steam genera-tor design, maybe it would be better for certain types of 1.,

j i

g j

accidents such as steam generator tube failures or steam lined brakes than a U-tube design.

So IREP was intended to g

i

g take an integrated look at the total safety of the plant and i

21 dbat's still going forward and will be a comparison on a total risk standpoint.

But I thought with regard to its n

n vulnerability of just the feedwater system upset there was 24 one more piece of evidence that says maybe all these thinga 3

that we 've done on this plant to try to reduce this vulnera-i sem vemame stoewsm isw.

I me same apreek sfuer. s. w. sures not i

S. L aus

l

• • ar we.

27 l

l I

lbilitygivenlongertimeconceptsreallyhaven'tachievedour i

objective and let's take another look.

9 i

CHMN. AHEARNE:

Now when is the IREP on Crystal j

s Il River due to complete?

I MR. TEDESCO:

In May.

6 I

l MR. DENTON:

I'm not here today proposing to add on 7

l these 18.

Almost all these 18 things are in the action plan l 8

l to apply to all reactors and what Bob is talking about is 9

l looking at a subset of that action plan item in terms of doing 10

! a fast on B&W plants.

Giving B&W higher priority than other 11 i

i plants or some slight shift.

So you'll find almost all these.

12 l

l items have been identified in previous studies but Bob is 12 l looking at them merely from the standpoint of sensitivity of I' feedwater upsets.

l i

j CHMN. AHEARNE:

And you don't see for example the l

large pas 7ibility of the recommendation you are making to go g,

l l in this direction than in May when IREP comes in.

la MR. DENTON:

And I'm not making these recommendatiohs 39 i

g today.

Even Bob hasn't finished his supporting risk of assess-l 21 ments of the impacts.

All we can--once we get the risk assess-

=

l ment impact of these it will have to be integrated in with.

22 i

the IREP study which will be coming out about the safae time.

l l

24 MR. TEDESCO: These people who are doing IREP are i

11 all larTWenaTieunaa. Veumafies Repowygum last I

den SSWThe GAMT46 STUuWr. L w, afgTE ISP l

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CDE 13/1 28 l

c.ar uc.

I i

I a little more particularly about the auxilliary feed water system, but they are related, I

so I

1 I

we can move onto the next slide which is concerns.of non-i

'N l

nuclear instrumentation, based upon the experience --

4 CHAIRMAN AHEARNE:

I should have picked up one 4

point.

i l

7 MR. TEDESCO:

All right.

I 3

CHAIRMAN AHEARNE:

Number 3 on the previous line, 9

would you say a word about that?

i i

10 MR. TEDESCO:

Yes, I will.

This has to do with I

11 the Davis Bessie plant, i

l Now, that plant had been originally designed to 13 l

have two steam driven auxilliary feed water pumps.

The i

I4 steam driven pumps depend heavily upon the availability j

of steam from the steam' generators.

l-id We have talked to the Davis Bessie people, and 17 most recently on the task force, and they have indicated

! a willingness to provide an extra pump that would not be 18 I

l 19 driven by steam.

It would be an adverse driven pump, either j

20 electrical or a diesel driven pu,mp, so they would provide f diversity in their aux feed water systems.

Il O

l CHAIRMAN AHEARNE:

Had that been a requirement 3

C for one of for one of these other --

f j

I 14 i

{

MR. TEDESCO:

All of them have it except this, j

13 Davis Bessie's the only one that didn't have it.

Imh '#WumTten h 34 e ab,N SammTM. Frier *. E e. aNTT W

~

-2 I -- -

29 I

l I

CHAIRMAN AHEARNE:

Yeah, what I meant was, had 2

! they been required to put in that through one of those other --

I MR. LENTON:

We have -- Before, remember, we 4

did do a risk -- reliability study of all the designs and l

I I've forgotten where this design ended up originally.

t i

j It must not have been at the high end because I

l it showed up again in this review.

We are now moving with l

3 that utility to have another pump installed.

i 9

i CHAIMUW AREARNE:

I thought that some place over 10 the last year we had asked Davis Bessie to do that?

II l

MR. NOVAK:

Well, in the shutdown order, the order i

i 12 itself did not specify a need for an additional aux feed 13 l

water pump.

Id i

In our safety evaluation, though, it was the l

1 IJ i

Staff's conclusions that a diverse pump should be added.

I4 Now, what probably happened then is the Staff I7 decided, well, we have this reliability study underway.

We i

i l

la should then see the results of the reliability analysis to l

l see what they have today and to see what the improvement

~

19 i

l 20 would be from the redundant top,,so it was a question of f

just doing it in that order.

II U

l CEAIRMAN AHEARNE:

But the Staff had previously l

already reached that conclusion?

I i

i MR. DENTON:

And I think you will find that in i

U many of these recommendations some of them have already 1

i-w me

.I seunem m steer *.te um te i

-3 f

30

'e coac na.

l I

been implemented because there were ongoing actions while the task force was going on.

t MR. TEDESCO:

Take the next slide.

Let's start dealing with the non-nuclear instrumentation, the point i

3 l

that Crystal River experienced.

I I

6 l

The results of our review of the information that I

7 l

we have at this point recognizes that there is further 3

review going on by another group of Crystal River, that we 9

make the recommendation that there should be better separation 5

10 and channelizing of power buses and NNI, so that one failure 11 in une bus would not knock out snch a large extent of the i

instrumentations that happened at Crystal River.

O We would also recommend that evaluations be done 14 i

to consider the safety aspects of the failures of the l

i IJ l

instrumentation where they failed at mid-scale, namely i

i 14 the operator would read an indication at half-scale, which U

would result in confusion with him, and just what that really I

la l

meant, to the point where he ignored his instrumentation.

i 39 l

And so we're wondering whether or not there 20 should be preference to a '-- at full scale or at zero scale, i

.l l

in preference of a mis-fail type of failure.

i t

~.

Also, whenev'er you have failures of this type, l

l i

U the operator certainly should be aware of it and control 1

'A systems should have the capability where we do not fail i

~

' in such a manner as to cause gross failures.

~~

i

== v m

sum ea===u.smer.te w=T *e

A' 31 l

i caer

c..

i There should be a better arrangement of the power lbusessothatyoudo'havetheredundancyofyourdisplay.

i COMMISSIONER GILINSKY:

May I ask you, Bob, --We A

i were going to conduct a review of the control system.

Would

!thisreflecttheresultsofthat?

J MR. TEDESCO:

The next part of the slide talks 4

7 about that on-going evaluation of the B&W report, INSAC and ll INPO have referenced it and we have an I&E bulletin and 3

9 we're recommending that we continue our action.

They're to all related.

l MR. DENTON:

I didn't think the INPO report did 11 t:

very much with the control system, did it?

13 l

MR. TEDESCO:

Yes, they talk about the operator, the display that he had, and about the control systems.

There 14 i

I i

are three areas that they talked about based on their review l

u l

1 Id l

of the Crystal River event.

I 17 i

MR. NOVAK:

I think this slide is not aimed solely is at control.

I think it's aimed more at the response that l

can be expected from the operator to the event.

19 I

I i

20 You may have gained -- You may improve the sensi-

)

21 tivity of the plant, how it behaves in terms of failure in the control system, but what you're really trying to l

1 i

get out of this is to connect the plant to the control room j

l inafashionsothattheoperatorcantaketheproperresponse.l 04 l

(

l!

I look at this and I think the instrumentation l

3 on n

vemm me

., - ~...

1

5' 1

32 i

cm %

I I

is the key that I'm looking for, the operator's ability j

I to understand what is going on with the plant and then l take appropriate actions.

I think the Crystal River III event and probably f many others suggest that the operator can't distinguish I

i 5

l valid information from suspect information.

I I

l COMMISSIONER GILINSKY:

My impression is that I

they pretty much ignored all the information and just saw 9

the PORV open and just decided they're going to keep pumping i

10 water until things cleared up.

6 11 l

MR. NOVAK:

There are alot of ways of describing i

U it.

That's also a true statement.

U MR. HANRAHAN:

Vic, that was a procedure that l

they were training to do in that event, following Three Id U

l Mile Island, was to continue the H -- high pressure injection I4 until subcooling could be verified.

U They couldn't verify it until they had the power f

18 back on the non-nuclear instrumentation which took 20 minutes.

l 19 MR. TEDESCO:

He lost his level so he had to l

I I

20 do it.

l U

COMMISSIONER GILINSKY:

May I ask something else

=

about that event?

I went down there and asked them how I

i many alarms went off, I wanted to have an idea of just 2#

what had happened.

{

And, they said, well, they hadn't -- the computer i=v%.

1

,.= em r-=c t,

s.--rte

6_

33

.i maar.*c.

I 1

hadn't gotten all the alarms because it wasn't working quite i.

I I right but they got 1400 alarms.

I It sounded like a rather large number to me.

And, 4

! what can anybody do with that or is that just for historical l

f purposes and you review that later?

I I

3 j

MR. DENTON:

Well, -- Let's turn the page.

I 7

(Laughter.)

l 8

Well, one of the recommendations that everybody 9

who's looked at TMI and Crystal River have, is to define 10 some safety factor, som e grouping of plant parameters that 11 safety grade you can really focus on or should be reliable, 12 that do tell you heat is being removed from the core and 4

l the status of major systems.

Id l

But Bob has proposed his group focus on this problem i

for loss of heat sink.

l U

I4 MR. TEDESCO:

This is recommendation number 6 I7 that we have, based on our lessons learned action, that we 4

i 18 believe that a select data set should be provide so that l

19 i

the operator would have a high degree of reliability and 20 assurrance of certain data that, reflect the condition l

of the plant and that it would be completely independent 21 i

U of the other instrumentation and provide a high degree l

of reliability.

U t

So, for those conditions where he may use or l

~

may question his other instrumentation, if given a select i

.w%

_ '7 34 e m..c.

l l

l l

data set, that would define the state of the plant at any 1

l time.

l t

I l

MR. DENTON:

Now, the action plan is moving l

forward on a somewhat longer time scale and they're thinking 4

I l

about more parameters.

i t

4 l

I think what Bob is recommending, that this set t

f of perameters for these plants maybe should be on a little 7

I differene. time schedule -than to try to get the fuller set.

9 But these address just the kinds of issues ve're i

10 talking about today since we have the feed water transient.

11 i

I think EPRI is thinking about 30 parameters I:

i maybe as being the set of which skilled operators can draw 13 l

all the necessary conclusions.

I

!4 i

CHAIRMAN AHEARNE:

Now, Harold, how should I

we be looking at this?

Is this a set that Bob has recommended l

!4 through his task force and you still have under consideration?.

I 17 MR. DENTON:

Yes.

la CHAIRMAN AHEARNE:

It has not yet reached the l

19 stage where you are recommending this as being the set that 20 ought to be done or, in particular, ought to be done sooner f

than othera?

Il I

i bm. DENTON:

That's right.

The bottom line of O

Bob's conclusion is the continue plant operation is permis-l 04 sable while these are firmed up, and so based on that, I'm l

13 awaiting advice from the ACRS as to the exact subset tand i

i===w=m. me.ime..

- e - r-er...

-m w.

J3 '

O 35 t

cumc.wc I

i I

then I need to incorporate it in with a larger set of i

a I

! action plans and decide resources and that sort of thing, l

so it's just an early indication of what we think the l differences may be between this class of plants and other A

I PWR's.

4 l

CEAIRMAN AHEARNE:

Now, Bob, when you looked 7

l at the set of items that you were recommending, what is I

I it that you would see the operator being able to do with

{

l 9

that set, continue to operate the plant or take the plant 10 to a safe shutdown?

l 11 I

MR. TEDESCO:

Well, we would consider that he i

II would be under an abnormal condition.

He would raise 1:3 l

a question about.whether or not he had reliable instrumenta-14 i

tion and the plant would probably be going through a transient i

U and may have tripped already.

l l

14 And so the question would be, what action should 17 he take, what procedures should he be following.

And, we j

18 believe that these set of data would allow him to make 1

I l

orderly systematic decisions on how far, if it was a hot I

19 20 standby or hot shutdown or even cold shutdown.

II CHAIRMAN AHEARNE:

Yeah, but you -- I was 5

just wondering, for example, why your list is so different i

U j

than let's say EPRI's list?

I i

i D

MR. DENTON:

I think EPRI's list tends tc deal j

with transients of a wider class or upset conditions of a l

in

= v im. = m s

.I m e W fyme=. E o anT 'er

9 c.ar so. 36 l

l wider class than Bob has looked at.

2 i

I think that what we are really reacting to is i

i I

that B&W plants do, the more we look, seem to be somewhat I

i j

different in response of this kind of upset than others, A

I and maybe we shouldn't be so --

i 6

l CHAIRMAN AHEARNE:

By now, I think -- Come i

l on, Harold, by now nobody has a question that seem to be 7

a different than.the response.

They are different than 9

response.

10 MR. DENTON:

Yes, that's right.

6 11 i

CHAIRMAN AHEARNE:

.And the question is, is l

=-

12 l

that significant and if significant, what has to be done.

12 l

But clearly they are different.

l 14 i

MR. DENTON:

Yes.

I MR. TEDESCO:

7 and 8 deal with other matters that 13 l

Id i

are related, and we have talked about these before.

17 CHAIRMAN AHEARNE:

On 7, do all B&W plants have --

I i

18 MR. TEDESCO:

Yes.

19 MR. NOVAK:

They all have it.

It used to be, before i

20 TMI that at the option of the licensee he could disconnect Il the operability.

l l

I2 It was part of the startup.

They might get --

,i 22 CHAIRHAN AHEARNE:

I see.

So they're there, but I

i 24 not necessarily connected?

U MR. NOVAK:

That's correct.

l l

i es WWRe W N. L e. aprPt W i

10 '

37 caer *e.

1 MR. TEDESCO:

The task force needs some guidance i and some help from the industry where people who own and i

t i operate these plants should give us their best evaluation l

and understanding of what ways that they might come up with A

3 whereby we would be able to reduce the sensitivity of 6

these plant.s, the reaction of them to perform this evaluation, 1

7 i

and --

1 I

3 I might mentio'n a few ways.

I don't want to 9

mention them as hard and fast ways, but they might be con-I to sidered as examples of what they may look at, one about i

11 i

perhaps lowering the T average on the plant, changing the 1:

levels and the pressurizer of a steam generator, and maybe 13 even changing some of the s et points on the trips and so 14 on, or even asking themselves what might be done if they 1.!

reduce the amount of super heat on the once through steam l

14 generator, and put more water in there.

17 l

COMMISSIONER GILINSKY:

Could I ask you about these?

18 l

Are the utilities that operate these plants uncomfortable 19 with this degree of responsiveness and are they seeking 20 ways to make the plants, as Harold said, more sluggish f in response, or are they saying, you know, it's okay, we'll 21 l

put up with what you impose on us?

j I

C MR. TEDESCO:

We have met with them and I think l

i 24 their attitude is encouraging, that they would like to j

U define ways of doing it.

i u._

- _vm.

i 1

1

u __.

11' 38 i,

l s.

c a s a:

• c.

I

\\

I i

I don't think anyone wants to go through a crystal River event that they'll end up with all that water on t

l the floor like that.

N 4

l MR. NOVAK:

I don't think the licensing individually i

l can look for the answer on his own.

It takes alot of technical l

6

{

expertise *r. look at the sensitivity.

I 7

l CHAIRMAN AHEARNE:

Let me see if I can't follow up i

I 3

on Bob's point.

9 Is the -- You said that no licensee wants to end 10 up with 40,000 gallons of water on the floor.

Another way 11 of interpreting that could then be if the licensees are 12 interested in a continuing examination so that NRC would l

13 l

change and modify it's regulations to avoid getting 40,000 I

14 i

gallons of water on the floor, which is different than I l

IJ think the point that Vic was asking.

l i

I4 l

MR. TEDESCO:

We are going to talk'about that I7 point, the very point you raised.

We're going to bring 18 that up in a minute.

i.

l 19 CHAIRMAN AHEARNE:

But what sense do you get --

i 20

[

I think what Commissioner Gilinsky was asking is, what i

II i

sense do you get from the licensees?

Are they concerned about the design of the plan +

o-are they concerned about i

i l

the NRC regulations on tire pe t

, ?

i Id MR. DENTON:

I think thers is a range of -- As U

typically occurs, I think some of the utilities I've talked mw=m. m. e.

i

,I

.=~ m==. s..m

-12

~

39 c.aa: m I

to are on their own considering ways to improve the safety i

of tPo plant and improve the understanding of the process.

i I think there are some other utilities who are j more in a traditional mold, awaiting for NRC action.

A i

e COMMISSIONER GILINSKY:

I realize the sensitivity i

and we all do of the subject, and obviously the utilities 4

7 l

don't want to raise questions about the safety of the plant i

g I

in such a.ay to get - -

9 COMMISSIONER HENDRIE:

Vic, I haven't run into l

~

ic operating people who have experience with the B&W system i

1; i

who are particularly apprehensive about it_.as a system.

i 1:

l I think there's a general recognition that one 13 l

of the things that you pay for having more advanced and l

efficient thermodynamic machine and that once-through 14 i

j generator and being able to operate the reactor at a good l

id I

high T and so on, is -- this overcooling, undercooling f'

i I

17 sensitivity, when you get a transient and_when you get a la control system malfunctioning.

19 But, I have found the operating people to be-i 20 especially, you know, worried or apprehensive about it.

i

1 I think people are interested in --

l Are you talking about actual i

operators or managers?

l 04 COMMISSIONER HENDRIE:

Well, both.

People with some experience in opearting, Crystal River operators, such.

l i

lNN N

'4 e e awmm. sterr=. t e an=r*e

13.'

. t.. -

40 1

caer.ec.

i l

CHAIRMAN AHEARNE:

Of course, it gets really i

2 i hard to find someone who has operated both.

l l

MR. NOVAK:

Well, you know, the judgment is l

l 4

l these people learn on --

J l

COMMISSIONER HENDRIE:

there are a number of 4

l people in the operating, who are in the operating business I

7 l

who have gone back and forth from one plant to another.

3 MR. TEDESCO:

Alot of Navy people.

9 COMMISSIONER HENDRIE:

And, you know, there's 10 good things to say for that system too.

i 11 i

I've got some long-range type questions to ask.

i 13 i

MR. TEDESCO:

We can skip the next slide.

13 COMMISSIONER AHEARNE:

No, no.

Let me ask a ques-14 i

tion.

You have number 11, the modifications to the extent IJ feasible to reduce or eliminate manual immediate actions l

i l

14 i

for emergency proceedures.

17 i

Now, does that mean that 'diat you sant to do is I

14 have more automatic controls or does that address itself 19 to modifying the actual construction of the steam supply 20 l

system?

l II MR. TEDESCO:

Well, what we're saying, on the

{

operating plants, there's a need -- the operator's required to take actions right away given certain conditions and 2d they're always of a repetitive type of thing, that they 3

should aither be automated or else other means done to i

e-m v me e p 6 FMagt". E e afP"T *W

~1 41 l

cms: *c l

1 I

l reduce the requirements that you place upon the operator.

i f'

For example, on a trip, he's always called upon f to terminate letdown and stop the injection pumps to maintain

~

! the level, i

f Now, does he have to do that or is it something I

i 6

that is a good action.

i I

I l

And, this is what we're balancing now.

It's more I

3 like he's told to do it, but he's not sure he has to do 7

it all the time.

So, it would depend upon the action. Here to we're putting the responsibility on the licensees and we II l

examine that requirement.

II CHAIRMAN AHEARNE:

But do you have -- if the con-i

~

m j

clusions you reach is that yes, these are things that should i

Id i

be done, would you then intend to incorporate.those as part I

U i

of the actions of the integrated control system?

f Id MR. TEDESCO:

Well,'I'm not sure in the integrated II l

controls system.

It would depend on what they are, really.

18 I think we --

I9 l

MR. DENTON:

I think the answer is no.

l I0 i

MR. TEDESCO:

I want to shy away from that.

I

• 1 think that's being called upon too much.

j MR. NOVAK:

They are not very substar.tial actions In reviewing the procedures, we've seen some things that 2

i are almost routine for him to do as an immediate response j

~

to any reactor trip he isolates letdown.

i i=v~%

- ~~ w-m. m. s.,m a

-15 1 --

42

-s t

c a s a:.we.

I i

I Well, in the view of trying to make the operator l

fhaveanopportunitytoobserveandnotevendiverthim I

2 from going over and iso 2 ating letdown, the idea is to

.' see if some of these acc.ans couldn't be performed automati-e l cally.

I 5

There's not alot of benefit here, but there is l

I l

some and we think we ought to investigate it.

l I

CHAIRMAN AHEAP;NE:

Okay.

In the operator training that you mentioned there, in your report you say that lec-tures should be developed and given concerning the Crystall 10 l

River III event and then quizes should be included.

I was just wondering, is this sort of a recommended 1d approach that you would have each time that there is such k

an event?

l I'

1 I'm not being critical or anything.

I'm just i

14 probing.

l MR. TEDESCO:

It would depend upon the event, and N

it is whatever we can do to upgrade the capability of the i

I i

M operators.

On the Crystal River III event we want them to really understand that NNI problem.

I aj i

And, quizes were -- You know, an example of it, l

i

~

as well as the simulator training.

l t

i l

The next slide I didn't intend to dwell on because j

• l l

a it was pretty well covered in 4.

j

~

CHAIRMAN AHEARNE:

When you say 18, you expect May? j i

t.__

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- same m truar. t e ee

._ ~.

l ', _ '

.I 43

[

~~

caca: ec.

I I

l MR. TEDESCO:

I'm told by May, yes, early May.

l Number 19 is something I'd like to share with you.

When f we started the task force we were wondering just what we

! could do about terminating the transients and finding ways a

I f

i to reduce the sensitivity of these plants.

What we came up with was the realization that

+

l there has to be a way of establishing acceptable criteria I

for transient other than' field failure and increases in 9

j reactor coolant pressure.

10 So, we came up with the recommendation that there II should be criteria developed to deal with the anticipated f

transient, not only for B&W plants, but for all white water t*

j*.

i reactors.

~

We have talked to the B&W --

i l

l COMMISSIONER GILINSKY:

What do you have in I

j 14 mind here?

Could you give me an example?

l MR. TEDESCO:

I wil3., yes.

We have ta?.ked to is I

l B&W and the owner group about how we might approach the I

19 development of criteria for acceptable perfonnance.

'o B&W has expressed great interest in helping i

• j l

us aut with these actions and they have come up with some examples of ways that we might do it, one of which would l

~~

~

be that we -- for a given event that we would call an j

A i

anticipated transient, a loss of feed water event, that

~

the reactor coolant pressure would never go to a point I

= v

~ m dEP ME.FW45 ShPTS. FP4EE". L 9 RFT"T t.?

=. _

37

.. l __

44

~'

caca:

I i

I where you would get injection of your high pressure system.

l 2

i The pressure would never get above the point i

~

where you would actually reactivate your safety valves.

l The reactor cooland temperature would never exceed 4

I l

the limit established in the technical specifications, that i

4 i

the reactor coolant itself could be contained in either I

7 l

or both the reactor coolant system and the drain tank, so 3

that you would not release the coolant into the containment.

9 You would maintain the pressurizer level on-scale 10 and as far as the once-through steam generator, the level 11 would be maintained there.

l l

!I These are examples that the.B&W people had come j

II l

up with in response to this particular recommendation, and l

Id i

they're encouraged by it.

We're encouraged by it, and we'd I

i j

like to also get the other designers involved, as well as IJ 1d INPO to see if we cannot get an industry action here to I7 develop such criteria, that would enable us in a better i

18 way to approach acceptable behavior for transient.

I i

19 j

I think we realize that we need more now than 20 what we have, if we?re experienced in these undesirable

.I events.

E COMMISSIONER GILINSKY:

The criterion is a design i

I U

criterion for the system, is-that the idea?

j I'

MR. NOVAK:

The system response.

i Part of the problem is, in the standard review i

l I

i-= v

~ w. r.

. - - w

.s.

m w,

14 '

..l 45 1

cm c.

f plants when you review anticipated transients and we've I

i always had a family of them, the criteria were basically l

I i

j that you shouldn't have the potential for fuel damage f

1 l

and second, you shouldn'.t have an overpressure event which exceeded the upset stress condition which is 110 percent i

6 l of the design pressure.

7 l

Well, those are easily satisified.

Well, first I

of all, you do your anal-ysis and set your trip set points 9

so that your SCRAM operates early enough so that you don't 10 suffer the potential of fuel' damage due to over heating.

11 i

And on the overpressure transient, then it's i

l just a question of seeing that the safetys are sized 13 properly to compensate for that event.

34 l

But then that lets your whole plant operate over I

i i

a very wide band.

So, that's one of the --

M 14 COMMISSIONER GILINSKY:

Well, you are saying that I7 you want to stay some distance away from those conditions?

18 MR. NOVAK:

Right.

You would like to pick then I

19 j

a band around nominal instances for a class of transients l

20 that have an expected frequency and that's going to be i

Il a problem, because you just can't use the definition of anticipated transient which we've traditionally used once O

over the life of the plant.

1 4

M You're going to have to be more practicable about l

the kinds of transients you expect with a reasonable i

I ineweism vemman= memoimm i=

as sawvm m svuur*. s e. marrt 'e l

19'

~

~46 l

raar c.

l l

i 9'

j frequency during plant operation and then to identify 2

l a band, say in terms of pressure, for example.

Over the nominal, you shouldn't have swings plus or minus some number.

And that would say that then the plant behavior, 5

th response is acceptable because it's behaved.

Now, it l

7 will only go out of that when you begin to compound i

3 additional failures.

~

l So, you're going to have a problem stcrting out, 10 saying, what is the transier.c that I expect and does it 4

f 11 i

have to be limited to a single initiating event or do I expect routinely some supporting equipment to perhaps U

fail and I still want the plant response to be within that l

band, or do I more or less find some other approach.

t u

Well, there's two sides of the problem then. We're 14 i

gonna have to deal with the kinds of transients that we expect and thiin set suitable response spectrum.

We just is l

j haven't had tlat.

We haven't had response on the plant.

i MR. DENTON:

I think this is exact? 2 the right

.'g way to go because it deals with.the output of the system, I

• 1 or the swing.

So many of the things we do deal with the i

input, so to speak, and we try to do something to effect f

~

the initial state of the system or --

'A He re we're finally getting to the way we want the "J

i m m von.m.no.wom =

1

2 0-. '

47 l

r.

esas na.

~

I i

i I

i system to perform under certain conditions.

b CHAIRMAN AHEARNE-And, what kind of criteria ii would you use to set the extended reliable swing?

L I

MR. NOVAK:

Well, Bob mentioned some of the i

f i criteria which B&W in the preliminary proposed which would 4

suggest that he wouldn't initiate S-class, you wouldn't l

i 7

Il have HPI come on for an anticipated transient.

I 3

You wouldn't c'hallenge the safety relief valves.

9 You wouldn't need to bring on certain pumps.

10 I

CHAIRMAN AHEARNE:

Those are --

i II i

MR. NOVAK:

Yeah, those are system responses.

12 CHAIRMAN AHEARNE:

Those are functional.

13 l

MR. NOVAK:

Right.

14 f

CHAIRMAN AHEARNE:

And I'm wondering if you have t~e a different --

I i

14 MR. NOVAK:

I have in my mind -- I would like 17 to pick a parameter ground.

I would'like to say for that la kind of transient, the pressure swing should be plus l

19 or minus 150 PSI.

20 1

l In other words, design your system so that it

.)

swings within that band and then your other equipment i

~

have to stay outside of that band and then that's the I

~

i way your response should be dictated.

i 04 they probably come very i

In all fairness to B&W, 3

i i===

v ri me w.m.

.I l

e amm. m sms-

.s.

art'e

l

'21'

'~

48

[

s.

casa:.s I

I t

t l close to meeting that kind of criteria today, if everything i

I I

j works well.

The answer is that you do have additional i

i failures.

You could take the Crystal River III event-or any t

i event and say that it wasn't just a single event, other things happened.

e 6

And so then the question is, how do you define s

i 7

the probability of that event occurring at such that you'd l

consider it to be an anticipated transient, that's the 3

problem.

to COMMISSIONER GILINSKY:

One thing that worried me it about that event was that the control system was telling l

12 the reactor to go in the wrong direction, and I think that's is worrisome quite apart from how far it goes.

I

4 Obviously at some point it's a set point.

l MR. NOVAK:

That's right, the rods were being pulled!

IJ 14 l

before the reactor trip occurred.

17 MR. TEDESCO:

The average was goir.g down and i

1:

I it was respr. ding the way it was supposed to do, but it U

l 19 was the wrong thing for that particular event.

i Oc MR. DENTON:

As someone said, that's an integrated

[

control system with a capital I.

It's got more fingers than 1

l do any other parts of the plant, than anyone elses' control f

s j

system.

i 24 MR. TEDESCO:

All plants have an integrated control i i

2 system to some degree, but this one, I guess with capital I ul -

i

-m m en,n= m N. L e aptt te

l 2 2 49 1

c.ar s I

I 1

i l

1s more responsive.

I f

COMMISSIONER GILINSKY:

Now, does this reflect an i

l

~

analysis of the suseptibility of that control system to i

A false information?

(

~

i MR. TEDESCO:

These criteria --

6 COMMISSIONER GILINSKY:

That seems to be the thing l

l that we hadn't looked at before.

Becausa, from what I under-l 3

stand from talking with you on an earlier occassion, was j

that we have looked at the control system and it geems to do the right thing when it gets the right information.

l 11 i

But, here was a case where it didn't get the right r

information, and we hadn't looked at that side of it.

i

,i MR. DENTON:

That goes back to one of the larger 14 j

recommendations of the action plan, is that we break down l

I l~'

this barrier between safety related and non-safety related.

l 14 i

Obviously the control system can influence a number of 17 challenges and instead of just disregarding it, it ought I

18 to be reliable and fairly dependable and do the right things 19 also and we're beginning to fold into those areas more and j

20 I

more to what the impacts are.

• 1 l

We recently have issued confirmatory orders to l

t

~~

l most of those B&W plants so far as a result of our meetings j

l with INPO to demonstrate that there are procedures and l

~~

l t

i l

Id that operators are trained in enough instrumentation to bring i

I

,w = cm r== - t,, - c-

.27 50 cm

.,e, l

l i

the plant to a standback condition when faced with this

! loss of AC or any other power failure in the control system.

i i

MR. TEDESCO:

The last slide --

4 I

Wait.

Number 22, J

MR. TEDESCO:

All right.

l To what extent do you intend 4

7 to involve Michael's on that?

i' 3

MR. DENTON:

When we talked about that one, it 9

didn't turn out to be as high a rate as the slide might have 10 l

indicated, about 20 percent.

11 i

And, -- Have you talked to Jack Heltemes or Michelson 12 l

about that?

13 l

MR. TEDESCO:

Not yet, but what we wanted to do l

14 i

is we just found this thing in our quick look that we couldn't U

explain the basis for it, so we figured we want to find l

out a little bit more about it.

We probably would talk to 14 17 Mr. Michelson about it.

I la There's also a question of how well you define LER 19 and how accurate they are.

20 l

CHAIRMAN AHEARNE:

I would imagint that's one of i

1 i

the problems he's wrestling with?

I l

MR. TEDESCO:

Right.

i l

CHAIRMAN AHEARNE:

It just seems that if you're

=

l l

24 l

going to have as part of an effort to be reviewing a subset l

U

, of LER's, atleast you ought to co-ordinate so that you don't l

i

)

i===,*= vom.i mamma w am sm

t. eve 94n, fruar?. E e. surrt var

24 51 1

i saca: Mc.

I have two groups.

2 i

MR DENTON:

I don't think this is as strong from i

i l

looking at the detailed statistic _s.

N MR. TEDESCO:

Well, that slide is kind of a summary A

of where we are, that the task force made has made 22 recom-e t

4 l mendations.

I We believe that our actions, as well as those are 7

i 1

3 going on now, certainly' lend support to the improvement 9

of the plant safety.

to MR. DENTON:

I guess the point'I want to make is i

11 l

you saw the numbers beside each one of these that refer i

r2 l

back to the action plans.

f Almost without exception, these are some variation i

12 l

14 l

reaction plan recommendations already, there are not still l

14 i

not more things to do, do them faster or do them in a unique i

i i

14 i

manner for B&W plants.

l MR. TEDESCO:

And, it's the task forces' position U

i e

la that continued plant operation is permissable.

However, 19 we feel that the reaction that should be taken now as I

i.

20 far as the operator training goes --Nov, these, at the time 21 we wrote the report and where we are today, some actions.have f

already been taken by issuing our orders out based upon the input findings.

{

l l

24 l

So, that effectively, these things are already 2

being done.

l l

25 j --

52 i

=

se c.

h I

CHAIRMAN AHEARNE:

Now, by operator training, you i

i I

mean reviewing what happened at Crystal River?

?

I l

MR. TEDESCO:

Yes.

l CHAIRMAN AHEARNE:

Now, let me ask you -- One of 4

f the problems that you had identified as a result of your J

1 6

l reviews of Davis-Bessie, Rancho Seco before, had been the l

lack of transmittal to operators of the information, not 7

I necessarily a lack of us putting it out, but the system being 9

instructed in such a way that the information didn't get i

l to the operators.

10 i

I 11 l

And you have here a recommendation saying that this, i

12 the operator should be alerted and trained.

Does that 13 mean that the system still isn't working, that the informa l

I4 i

ion at Crystal River wasn't getting to the operators?

l IJ j

MR.,TEDESCO:

We have the I&E man.

Don, I wonder l

i I

14 i

if you can help answer that?

j I7 Don Quick from Region II in Atlanta who is the man i

18 on Crystal River.

19 MR. QUICK.

Yes, I've been project inspector on j

i 20 i

Crystal River for the' last two years.

I don't think it's I

U f

so much a problem of the operators being aware of a specific event that took place.

i 5

I do, however, think it is a problem of them being i

j 6

i I#

aware of the specific details of that particular transient with respect to the applicability to their facility.

i

~ ~,

26 53 a

c eaca:.aec.

l 1

For example, during the event of last November, i

we issued a PN, preliminary notification and also a bulletin l

I which called for all the licensees to look at the applicability l

l of that event to their facility, 1

i l

3 That particular event or bulletin was reviewed i

I 4

by the operators at Crystal River, however they did not get i

7 l

into the details of the specific things that went wrong at i

I 3

Acony and look at that from that standpoint on their particu-9 lar plant, until we basically emphasized that part of it, and i.

10 they then did a thorough review of their system.

I F

11 i

And I think that's the area where this is really i

II i

worth while.

13 CHAIRMAN AHEARNE:

Well, maybe I'm missing something, la i

but it sounds like the same kinds of A croblem and B solution l

j that we all have been saying ought to be done for over l

l 14 a year every time one of these events occurs and I guess I'm I

17 a little concerned that it has to be elevated to a specific i

i la i

recommendation.

j I don't take any exception to the recommendation, 19 i

20 l

but I would have thought by now we were getting to a system i

21 l

whereby when an avent occurs, that the information is i

distilled in such a way that operators of other similar i

i plants do get, as you say, the essence of --

l t

24 MR. DENTON:

I guess -- I don't have a good U

feel for whether it's getting there.

Doyouhaveaninspector!

t wTupunaftsuns% VWinavies Demarrgus seur.

27

,. ~

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54 cost sc.

I from another B&W plant?

i I

MR. QUICK:

If I could make one more comment on I

f this.

For example, when Rancho Seco had the light bulb incident, the Crystal River operators, per se, knew very i

I little about that event.

3 j

I think almost across the board, that is the type I

+

t l

of semination that you get.

It's disseminated to management I

3 within the facilities, b'ut not necessarily to the operators l

I 9

in the details that they need to recognize that particular 10 problem on their facility.

II CHAIRMAN AHEARNE:

But that is their -- and is I2 one of the critical problems that had been identified in 13 i

a previous review.

This doesn't really sound like it's a 14 Crystal River B&W problem, it sounds like we still have that i

same problem.

l IJ l

I guess whether I'm not sure whether it's NRR or Id i

II I&E problem, but I guess I will speak to them.

II MR. DENTON:

In this one, by following up with l

19 i

confirmatory orders, it does require that the licensee j

l i

demonstrate that the operators are trained and they Lave i

l II l

procedures to cope with this.

=

I CHAIRMAN AHEARNE:

I understand that.

l I

l MR. DENTON:

But, let me commit to looking into i

i t

how well this got disseminated.

l

~

CHAIRMAN AHEARNE:

Because it really is, it's i

mw-=, %.

28

• i 55 r

.e.

i i a product of question.

t l

MR. DENTON:

Yes, it may have been well dissemina-l I.

l ted and we may be redundant.

l l

i A

i CHAIRMAN AHEARNE:

Well, but the Crystal River I&E 3

inspector is saying, for example, that Ranch Seco information i

6 i was not.

i 7

1 MR. DENTON:

No, but I thought you were asking i

1 l

about --

3 9

COMMISSIONER HENDRIE:

That was kind of pre-TMI.

to Don, isn't it -- It's my impression from the contacts I

i 11 i

I've had in the field that there'is a good deal more discussion i

g:

these days of other people's transients than there used 12 to be, and more interest on operators part.

14 j

The problem you're emphasing is the-fact that 20 l

IJ j

licensed operators at Crystal River had scanned across an l

14 i

account of say the Acony event and have some general aware-17 l

ness of it.

i la l

That's valuable, obviously, in itself, but that's rather different than having the, whoever it is in the

9 j

i

c operations group that needs to do it and maybe their safety i

1 l

committee sit down and review Crystal River's particular l

l design and operating procedures and see where things might i

need to be changed and then implement that in terms of i

04 changes.

The latters are much more -- It takes alot more and I guess any operating organization is going to have to

?

i

'T_Y.U"U_

.~..

-29 56 casa: *c.

l i

l try to be selective with a number of events.

l 2

j MR. DENTON:

Those functions are being spelled i

j out in the new licenses where we define the on-site engineer-A i

ing group, and the technical advisor, review other people's 3

LER's, a much more specifically defined action than it was t

6 a year ago.

7 l

MR QUICK:

Just one short comment on that.

I i

l 3

think the amount of information that gets to the operating l

9 level is very dependent upon the view that the plant manage-1 10 ment takes with respect to that particular transient and i

I P

1; i

it's applicability at their facility, f

1:

l If, for example, Florida power decides that the is Acony event has very little applicability at their facility, i

14 due to the differences in design of the X &"Y power trains I

on NNI, then the event doesn't get disseminated very well.

le If it's decided that the event does have a high 14 i

I 17 l

applicability, then yes, they would know much more about i

is it, and I think that's the real key to this thing.

I Well,that'sunderstandable.i 19 COMMISSIONER GILINSKY:

I c

It seems to me that we regard the Rancho Seco event rather

1 I

lightly.

It wasn't -- an abnormal occurrence, so I think i

it's not surprising that others didn't pick up on it.

j COMMISSIONER HENDRIE:

But that's not the standard I

24 because an abnormal occurrence has a specific definition U

currently under the rules.

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l casa: ave.

57 I

I f

COMMISSIONER GILINSKY:

Well, I wasn't speaking I

in a strictly legal sense, but -- We didn't attach alot of importance to it.

4 I

In a way, I wonder if you could shed some light I

on why that is, why in fact we didn't?

I 5

i CHAIRMAN AHEARNE:

Once again, that's pre-TMI.

7 l

cqMMISSIONER GILINSKY:

No, I understand that.

?

I I'm just trying to understand what we thought about that.

7 In other words, why was it regarded as being something that i

f didn't have great safety significance?

10 11 CHAIRMAN AHEARNE:

It's because we didn't take i

II it to the staff and say what if one more thing had gone wrong, 13 l

how close were they to getting into a TMI situation or a i

{

Crystal River situation.

14 i

L!

We didn't take the LER's and through in one more l

l Id failure.

I7 COMMISSIONER GILINSKY:

Was it just that the effects i

18 were not all that extraordinary and therefore, they didn't 19 lose alot of water.

i 3

CHAIRMAN AHEARNE:

By looking at the consequences, U

the consequences were acceptable and we didn't postulate O

additional failures, which they might have been very close i

U to additional failures.

i i

MR. TEDESCO: Well, that finishes our presentation i.

as far as the status of our evaluation.

We are awaiting I

i in men.m. me ins.

I 1

31' l

58 l

pact se i

1 f

1 section 7.

We should have alot of interest for it, because f it's one way of --

I 2

l CHAIRMAN AHEARNE:

You say that's sometime this i

! week?

d I

3 MR. TEDESCO:

This week, yes, sir.

i I

6 CHAIR N AHEARNE: And you still are going back i

7 l to the ACRS?

i I

MR. TEDESCO:

'We are going back.

f 9

i CHAIRMAN AHEARNE:

I guess, what is it, they j

r 10 didn't finish, so they have not -- They're not yet ready j

11 l to send us a letter or anything?'

g7 I

MR. TEDESCO: They want Section 7 too.

I think 13 that's our milestone right now.

14 MR. NOVAK:

Could you before you finish say a l

13 1

\\

word about the event that took place at Davis Bessie.

I 16 got the idea there was some partial loss of instrument i

17 power?

18 l

MR. DENTON:

I know a little about that event.

19 l

i I was called over the weekend.

The plant had been shut j

,0 l

down for a couple of weeks and there was a loss of AC

,1 4

i power, but I don't remember that I knew the exact cause.

i This led to activation of the -- one of the 3

l emergency core cooling system pumps which was hooked up 24 3

to containment sump, the sump had very little water in it, i

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me SEnMes N FFIIST. E w. IBMTR 187 -

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32 59 I 2

raar sc i

i I

i led to air binding of the pump, and so in effect they i

2

! -- because of that AC power failure, they lost the ability 2

! to remove heat from a reactor that had been shut down for i

ftwoweeks.

The primary system temperature went up'for a 8

i couple of hours before they could get the RHR system working.

~

t 6

j again.

7 I

At the time I heard about it, the situation was t

t I back to normal and back.to control.

Maybe someone can 7

I i add a few more specific on it.

l 10 COMMISSIONER GILINSEI:

Well, I was more inter-i 11

ested in whether you thought it bore on anything that 1"

l we discussed today, i

13 l

MR. NOVAK:

Well, I asked that question of the 14 i

! plant superintendent just around lunchtime.

It may be l'

unfair to him, because in view of what we have been talking 16 l

i about in our task force, had you made these changes and 1,,

j if they were in place, do you think the event would have 18 I

been changed markedly.

And, his initial response was no, 19 i

I l

he didn' t think so, 3

l l

He did think, though, to be honest, that if we 21 I

hadn't responded -- He's got some licensing Emendments i

i pending.

I knew I asked one more question than I should i

l

! have.

i 24 3

He said, then it would have -- Then the course en WR,DeGaMPek STuuWT.& w. StNTEest i

1

4. & Juum l

.33 l

60

=

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l I

I l

1 I of the transient would have been a little different, so 2

he got his licks in on the second half.

2 They were -- This is their first refueling.

They

..were doing a steam generator tube inspection, so they had l

fdrainedtheprimarysystemdowntopermitthattobedone.

I i

j They had a nonessential buscfailure. Igain, i

I 7

! it's related to what we've been talking about in seme way l

5 I that I'm not prepared to' talk about.

l 9

j It did initiate an SFAST, but the loss of power --

l 10 l Again, this is the automatic feature, indicated that the 11

! water storage tank had already emptied, so what happened, 12 l

I is the system automatically went into a recircle --

13 l

COMMISSIONER HENDRIE:

Switched to the sump?

14 i

MR. NOVAK: Right, and then it was pumping.

It 13 I

I was just dry, and so the pumps were air-bound.

14 j

They experienced some difficulty in their first 17 1

approach in clearing the air from the pump, you sort of l

I8 l

try to bleed it locally.

li I

l l

They weren't as successful, and they finally 20 l

opened the valve from the BWST and let the head of water

,1 4

more or less push the water through and they recovered i

I quickly.

i n

I i

24 They did -- But for some -- And then you have a l

n clear path also, perhaps into the containment sump.

It's i

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34 61 i

I l

esas ne I

I l my understanding I&E does have people up there today.

They r

I left yesterday and they're at the site, so we'll await 4

~.l,their review of the matter.

e I

CHAIRMAN AHEARNE:

Joe, you had some more ques-i i

~

! tions?

l 6

j COMMISSIONER HENDRIE:

It doesn't sound very 7

l l profc3nd to me.

That's a general -- I guess more remarks 8

I than anything else.

9 I

I suspect that long ago we should have decided 10 that the auxilliary feed water systems were engineered to 11 i

safety features, and we got started off with them as just 1:

i i

good things to add to the secondary side of the plant and I3 i

as time went along, why we kept -- We've been upgrading 14 i

l auxilliary feed water systems bit by bit, for a good many i

ic t

l years it seems to me.

j Having let them be put into plants the way we have, even with the upgrading, I think we can go along 3,

i way in terms of the control features and the single 39 I

failure stuff.

I gg 21 I must say, I'm not very optimistic that it's very profitable to talk about making them sized in category

.l i

l 1, that they're bolted down in auxilliary buildings, auxil-l n

24 liary building or whatever.

'J l

And I further am not much perturbed about whatever t

f twrwoum venom stupemps, lac due Sant?te GeMMui. ffnugt. & w. surrt ser j

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35 1

i 62 l'

=

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nas um I

I i

jincrementalrisklevelthereisbetweenseismiccategory 1

I

! 1 and not for these plants at this time.on the thing.

2

'~

So, I must say for myself that I wouldn't sweat j

s il whether or not you could in fact come all the way up to I

5 i

present seismic category 1 requirements.

6 MR. TEDESCO:

In that regard, we are looking 7

at the capability for treating bleeds that wouldn't have 3

the capability of the backup --

7 COMMISSIONER HENDRIE:

Just so --

10 l

MR. TEDESCO:

Not necessarily then have to go 11 l

i in and rip out concrete and put in brand new systems, if I

the capability is already there.

I3 COMMISSIONER'5ENDRIE : Well, one of the things i

about the seismic business that worries me a little bit l

g l

is I would hate to s'ee us so enthused over trying to meet 9

i

7 some sort of earthquake standard that we find ourselves j

is l

going into plants and having people hang alot of additional s.

19 l

hangers, restraints, snubbers, and heavy duty hardware l

20 in general, aux feed water lines and connected things.

21 I guess I continue to feel that a certain amount i

l i

of flexibility in piping systems and willingness if push l

1 1

f comes to shove, in a big earthquake, to use the intrinsit 22 i

Id ductility of the piping system that isn't over restrained, l

i i

I

-e j

is a safer and better route than trying to tie everything i

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1 down where your chance of error in the restrain is sub-l 2

l stantially larger.

2 l

MR. DENTON:

Well, I think, if I can say what i

you're saying another way, there are some things for which I

a l

an engineered safety feature should operate, that are i

l sufficiently remote, and I think our main thrust here 7

l was to try to eliminate the challenges that come from 8

l normal operation and move out in probability space as 9

i far as we can reasonably go.

10 COMMISSIONER HENDRIE:

I think for the -- You 11 know, it's a good question for the long term and particularly 12 for new designs, if we're blessed with having an opportunity 13 to look at such, it's a question of residual heat removal 14 12 systems and auxilliary feed water systems for PWR's that i

f

!' seems to me, they're gonna run together and require a 14 very high reliability full safety grade, full after heat 17 i

and stored energy rated system, which may -- which could I

be a separate one like a full system pressure safety I'

l

)

l grade, RHR, with a heat rating to take the machine right 20 I

after SCRAM, or it could be in effect, an aux feed system g

which would use the steam generators as the Feat exchanger i

t I

g because they -- are there and do have te 'aang tocather.

1 24 So, it seems tc me for new designs, those i

I '

systems probably will end up combining into a single 5

t i

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{systemwhichwouldconsiderablyenhancereliabilityandso t

2 on.

That's probably a good way to go.

l I

3 I was out yesterday doint one of my field practices d

on a BWR-3 system, and you know, things go, the heat water l

3 system drops out of it and maybe some other thing, you u,

have some other failures and there doesn't seem to be much I

6 I

else handy to'do and you have your choice.

You can either i

I fwaitfor15ro20secondsandthevalvewill'opentopermit 9

the isolation and condensor to come into duty, or you can t

to go over and punch the button and save 20 seconds and then i

11 l

you can go sit down and have a cup of coffee and eat your l

12 lunch and after some hours, why you ought to get a fire f truck in, if you haven't got any power at all, to pour 14 i

i some water in the shell side of that condensor and outside 13 of that, why the plant just runs along taking care of itself i 14 l

just fine, black out or what have you.

e 17 I

And, the,t kind of -- That kind of very reliable, la 3

I very simple sort of system has an enormous -- It provides 19 i

a very high degree of confidence that you can get through 20 l

all kinds of events and multiple failure sequences.

,1 4

CHAIRMAN AHEARNE:

Bob, did you have a comment j

i I

l l

on that?

I i

l 3

MR. BUDMITZ:

Just one quick point.

There's a 5

i 3

assumption which underlines all of this which wasn't i-

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I spoken, and which the research program is addressing, and i

2 that's the assumption that the phenonema behave in these

[

3 transients the way we think they do.

l You know, you have a transient, an overcooling a

transient or another kind of small break.

i And, we're not yet in the posession of engineering 7

computer codes that can predict accurately all of the 3

l

.l phenonema here, although we have alot of confidence.

9 And the goal of much of the research program in the to next -- I'd say it's three-four years, is to develop thos 11 codes, test them, and then having found them acceptable 12 i

for use, then we're going to run them on all the different 13 l

l kinds of plants and all different kinds of transients, two i

of the plants, three of the plants, four of the plants, i

13 l

and so on, OTSG's, all the different parameters.

16 And although I think we're confident that the systems are going to behave as we think, until that's true, 18 i

that's still an assumption and people ought to remember 19 i

that it's not just B&W that's separate there, all the

,0 4

I different kinds of -- We're not gonna know until we're done.

3 1

COMMISSIONER HENDRIE:

Does that mean we shouldn'ti n

cut the research budget in '817 4

MR. BUDRITZ:

No.

i J

l 2

CHAIRMAN AHEARNE:

Ed, did you want to make any i

i n

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