ML20197C834

Transcript of the Advisory Committee on Reactor Safeguard 675th Full Committee Meeting - July 10, 2020, Pages 1-189 (Open)

ML20197C834
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Issue date:	07/10/2020
From:	Advisory Committee on Reactor Safeguards
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Snodderly, M, ACRS
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NRC-0962
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Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION

Title:

Advisory Committee on Reactor Safeguards Open Session Docket Number:

(n/a)

Location:

teleconference Date:

Friday, July 10, 2020 Work Order No.:

NRC-0962 Pages 1-182 NEAL R. GROSS AND CO., INC.

Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.

Washington, D.C. 20005 (202) 234-4433

NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1

1 2

3 DISCLAIMER 4

5 6

UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7

ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8

9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.

15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.

19 20 21 22 23

1 UNITED STATES OF AMERICA 1

NUCLEAR REGULATORY COMMISSION 2

+ + + + +

3 675TH MEETING 4

ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5

(ACRS) 6

+ + + + +

7 OPEN SESSION 8

+ + + + +

9 FRIDAY 10 JULY 10, 2020 11

+ + + + +

12 The Advisory Committee met via Video-13 Teleconference, at 11:30 a.m. EDT, Matthew W. Sunseri, 14 Chairman, presiding.

15 COMMITTEE MEMBERS:

16 MATTHEW W. SUNSERI, Chairman 17 JOY L. REMPE, Vice Chairman 18 WALTER L. KIRCHNER, Member-at-large 19 RONALD G. BALLINGER, Member 20 DENNIS BLEY, Member 21 VESNA B. DIMITRIJEVIC, Member 22 JOSE MARCH-LEUBA, Member 23 DAVID A. PETTI, Member 24 PETER RICCARDELLA, Member 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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2 ACRS CONSULTANT:

1 MICHAEL CORRADINI 2

STEPHEN SCHULTZ 3

4 DESIGNATED FEDERAL OFFICIAL:

5 CHRISTOPHER BROWN 6

CHRISTIANA LUI 7

QUYNH NGUYEN 8

MICHAEL SNODDERLY 9

10 ALSO PRESENT:

11 ANTONIO BARRETT, NRR 12 BRUCE BAVOL, NRR 13 JOSHUA BORROMEO, NRR 14 TRAVIS BOYCE, NRR 15 ANNA BRADFORD, NRR 16 BEN BRISTOL, NuScale 17 LARRY BURKHART, ACRS 18 MARK CHITTY, NuScale 19 PAUL DEMKOWICZ, Idaho National Laboratory 20 MICHAEL DUDEK, NRR 21 SARAH FIELDS, Public Participant 22 CRAIG HARBUCK, NRR 23 JORDAN HOELLMAN, NRR 24 PAUL INFANGER, NuScale 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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3 MARIELIZ JOHNSON, NRR 1

SHANLAI LU, NRR 2

MICHAEL MELTON, NuScale 3

SCOTT MOORE, Executive Director, ACRS 4

ETIENNE MULLIN, NuScale 5

TONY NAKANISHI, NRR 6

STEVEN NESBIT, EPRI 7

RYAN NOLAN, NRR 8

REBECCA NORRIS, NuScale 9

REBECCA PATTON, NRR 10 TOM SCARBROUGH, NRR 11 JEFFREY SCHMIDT, NRR 12 JOHN SEGALA, NRR 13 ALEXANDRA SIWY, NRR 14 ANDREW SOWDER, EPRI 15 DINESH TANEJA, NRR 16 CARL THURSTON, NRR 17 CHRISTOPHER VAN WERT, NRR 18 YUKEN WONG, NRR 19 PETER YARSKY, RES 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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4 P R O C E E D I N G S 1

11:45 a.m.

2 CHAIR SUNSERI: This is Chair Sunseri.

3 It's 11:45 and we are going to reconvene the ACRS 4

meeting. Let's start with a roll call.

5 Ron Ballinger?

6 MEMBER BALLINGER: Here.

7 CHAIR SUNSERI: Dennis Bley?

8 MEMBER BLEY: Here.

9 CHAIR SUNSERI: Vesna Dimitrijevic?

10 MEMBER DIMITRIJEVIC: Here.

11 CHAIR SUNSERI: Walt Kirchner?

12 MEMBER KIRCHNER: Here.

13 CHAIR SUNSERI: Jose March-Leuba?

14 MEMBER MARCH-LEUBA: I'm here.

15 CHAIR SUNSERI: Dave Petti?

16 MEMBER PETTI: Here.

17 CHAIR SUNSERI: Joy Rempe? Joy Rempe?

18 Pete Riccardella?

19 MEMBER RICCARDELLA: I'm here.

20 CHAIR SUNSERI: Okay, we have a quorum.

21 So, let me first start off by saying I appreciate 22 everyone's patience with the Committee as we work 23 through the previous P&P agenda. We ran slightly over 24 and we needed to take a short break before we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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5 reconvened this session, so I do appreciate everyone's 1

patience on that.

2 We are going to start the letter, the 3

report preparation phase of our review of the boron 4

distribution issue regarding the NuScale DC 5

application. This is going to be a little different 6

than what we have historically done.

7 We don't have a draft letter yet to 8

review, so I've asked Walt. He's going to conduct, 9

Member Kirchner is going to conduct a facilitated 10 discussion of what the content of that letter should 11 be with the members.

12 During that discussion, we are going to 13 have transcription going on. So, we have a 14 transcriber that will capture this discussion so that 15 we will have the information available to us as we 16 prepare our report, and it will also be of public 17 interest, I am sure, as well.

18 So, we will keep the transcription running 19 until the point of which we have either ended our 20 discussion or are ready to put up some kind of draft 21 letter in front of everyone, which I don't anticipate 22 that happening until very late this afternoon, if at 23 all.

24 So, let me ask members, are there any 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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6 questions with where we're proceeding before we get 1

started? Okay, and let me just confirm that the 2

public line is open.

3 MR. SNODDERLY: The public line is open.

4 CHAIR SUNSERI: Okay, and with this, I 5

will now turn it over to Member Kirchner, lead for the 6

NuScale DCA review.

7 MEMBER KIRCHNER: Thank you, Mr. Chairman.

8 Good morning, everyone. I want to keep my opening 9

remarks brief because, as the Chairman has indicated, 10 we would wish to have a facilitated discussion with 11 the Committee, but before we get there, I want to do 12 the following.

13 I just want to thank both the applicant 14 and the staff. I know there has been a lot of work 15 done in a very compressed time. We are aware of that 16 and appreciate it.

17 The preparations over the last several 18 months, the presentations I should say, have been very 19 informative, and that will help our discussion today.

20 I again think we're at a point now -- I 21 don't want to get into my personal views at this 22 point. There will be a chance for me to also join the 23 conversation in a bit, but I'd like to summarize where 24 I think we are.

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7 We had a very nice summary from Meghan 1

McCloskey of NuScale yesterday morning. Thank you, 2

Meghan. That was a good summation of where things 3

are, and we had excellent presentations from the 4

staff.

5 I would single out -- I shouldn't single 6

out anyone, but I do want to point out that in Jeff 7

Schmidt's presentations, we had what I'll call figures 8

of merit for gauging the boron dilution issue, and it 9

appears, at least in this member's opinion, that the 10 design changes that have been made by the applicant 11 certainly address the DHRS cooling part of the 12 equation.

13 I think in general, the concern now turns 14 to the post-ECCS boron dilution of the downcomer, 15 dilution of the downcomer, and I'm going to turn next 16 to Jose March-Leuba, who has been our lead on this 17 issue. He is going to try and establish some points 18 of reference, I'll call them, as to where we are.

19 And I'm then also going to turn to Member 20 David Petti who has put together a nice flowchart that 21 may also help facilitate focusing our discussion, and 22 then turn to you, the members, for your input, and 23 also to our two consultants.

24 And with that, I will hand the microphone 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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8 over to Jose.

1 MEMBER MARCH-LEUBA: Here I am. Mike, did 2

you get my write up?

3 MR. SNODDERLY: Yes. Sandra, if you could 4

share your screen? In that same folder where Dr.

5 Petti's flowchart, I have placed Dr. March-Leuba's BD 6

summary. Could you please bring that up? Thank you.

7 MEMBER MARCH-LEUBA: All right, so while 8

Sandra is working on that, I think what --

9 MEMBER KIRCHNER: Jose, just one quick 10 thing. In my opening remarks, I didn't -- I wanted to 11 call special attention both to Dr. Peter Yarsky's 12 presentation and a differing view from Dr. Shanlai Lu.

13 Those both were excellent and will help inform our 14 discussions, so thank you both.

15 MEMBER MARCH-LEUBA: So, before the 16 Committee writes a letter, we have to have an 17 underlying agreement on what the facts are as we know 18 them today.

19 To start with, there is very little 20 documentation on this issue. All -- almost everything 21 you're going to see now on my write up is either I 22 rationalized myself or it was said orally by either 23 the applicant or the staff, okay. Sandra, are we 24 making any progress?

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9 MS. WALKER: It's loading.

1 MEMBER MARCH-LEUBA: Yeah, there it goes.

2 Now, I made an effort to not put any numbers in here 3

that I wasn't 100 percent sure they were not 4

proprietary, so I think -- I'm pretty sure this is not 5

proprietary, but at any moment, if anybody sees 6

something proprietary, please let's stop sharing the 7

screen and we'll go into closed session, okay.

8 So, again, this is trying to establish 9

facts so we can then transfer them to our letter, 10 right? On the positives, they're having two design 11 modifications.

12 Number one is the riser holes which 13 prevent downcomer deboration during controlled passive 14 cooling events, and both the applicant and the staff 15 have done analysis that show that they're effective.

16 That's good. That's excellent.

17 An additional problem was ECCS actuation 18 too late, and for that, they changed the ECCS end 19 points, and through exhaustive analysis, both the 20 applicant and the staff confirmed that that problem 21 has been solved.

22 So, we have two positives, okay? When you 23 end up into uncontrolled passive cooling events, you 24 don't deborate anymore, and ECCS involves, not mainly, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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10 the RRV opens early enough so that the rush of 1

deborated water does not get into the core.

2 Sandra, can you move up to 17, line 17?

3 All right, however, the modifications fix those two 4

problems. Late ECCS actuation or deboration of the 5

downcomer or with circulation with DHRS did not fix 6

the problem with ECCS actuation.

7 So, after ECCS actuates, we now know from 8

NuScale, they admitted yesterday, it's not only 9

possible, it will deborate, and it will deborate in a 10 few hours. NuScale or the staff have not performed an 11 accurate calculation of how many hours it takes.

12 So, they used conservative numbers from a 13 calculation that was performed for something else, 14 okay, but we know it deborates and we know it 15 deborates certainly within the 72-hour period we 16 considered.

17 We also know that the downcomer volume 18 that has been deborated now is 14 times larger than 19 the core volume. So, if we push any of that downcomer 20 into the core and some mixing occurs, which it will 21 even though we don't have any evidence that it does 22 because we don't have any calculations, you still have 23 14 volumes, 14 core volumes coming behind it. So, 24 even if the fresh run mixes and gets some boron, you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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11 keep bringing deborated water behind it. It is 1

unreasonable to say that you are not going to end up 2

with a non-deborated, a non-borated core if you start 3

CFDS or CVCS.

4 Furthermore, there were some statements 5

yesterday that we don't believe that 20 dollars, that 6

there are -- it's going to shut down by 10 dollars.

7 There were a lot of blanket statements 8

orally by the applicant, but when the staff asked the 9

applicant to calculate what is the probability, what 10 conditions would result in criticality in the core 11 using the standard methodologies that they would ask 12 Browns Ferry, or Brunswick, of Susquehanna to use, the 13 return to power is predicted and a critical boron 14 concentration that requires minimum deboration.

15 And I can't tell you the number because 16 that's proprietary, but it does not require to 17 deborate the whole downcomer down to zero. I mean, it 18 is a very small deboration of the downcomer that gets 19 you to the CVC.

20 Furthermore, the return to power is 21 possible for the whole cycle, beginning of cycle, 22 middle of cycle, and end of cycle. The end of cycle 23 was analyzed. Maybe that's Chapter 15.0.6, I believe, 24 and we agree that was GDC-27.

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12 We agree that that was okay, that that 1

could not violate SAFDLs and everything would be okay, 2

but BOC and MOC return to power has not been analyzed.

3 The consequences are known, but the potential core 4

damage cannot be discarded.

5 You have 20 dollars worth of reactivity 6

with 14 times the volume of the core coming into the 7

core, coming into the core, coming into the core. It 8

has not been analyzed, okay, but the consequences are 9

terrifying.

10 Furthermore, the MCNP calculation, when 11 the staff asked the --

12 MEMBER KIRCHNER: For the record, Jose, 13 the consequences are unanalyzed.

14 MEMBER MARCH-LEUBA: The consequences are 15 unanalyzed, but 20 dollars worth of reactivity coming 16 into the core are terrifying, okay. I mean, it is --

17 MEMBER KIRCHNER: One more time, we need 18 to -- let's be objective, and this is just one 19 member's view. We're on the record.

20 CHAIR SUNSERI: And I would just add, 21 Jose, I mean, you are asking us or describing to us 22 facts as you put it, as you said. I don't know that 23 it's been established that the 20 dollars is a fact.

24 It's a supposition on your part. We heard a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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13 supposition from others of a different value, so --

1 MEMBER MARCH-LEUBA: Oh, no, no, hold on 2

a minute. Hold on a minute. That is a fact. At the 3

beginning of cycle, you have 1,200 ppm of boron in the 4

holders, and the boron coefficient varies from seven 5

to 14, and the recommended value to use from NuScale 6

is ten.

7 So, 1,200 ppm of boron results in 12,000 8

pcm of reactivity, which is 20 dollars, maybe 25 9

dollars. Some people said 21 dollars. Some people 10 said 29 dollars, and the staff in their SER says it's 11 29 dollars. That is a fact.

12 MEMBER RICCARDELLA: I object to the word 13 terrifying. I don't think that's a fact.

14 MEMBER MARCH-LEUBA: Okay, that terrifying 15 is not a fact, but if you insert that much reactivity 16 into the core and you don't do an analysis that tells 17 me that you have sufficient feedback reactivity, what 18 do you think is going to happen? I don't have an 19 analysis.

20 MEMBER BLEY: Jose?

21 MEMBER MARCH-LEUBA: Yes, sir?

22 MEMBER BLEY: Maybe this would go better 23 if you stick to your bullets.

24 MEMBER MARCH-LEUBA: Yeah, okay. So, back 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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14 to the ability to make the core critical with this 1

front. When the staff asked NuScale to calculate how 2

far the deborated front had to move into the core 3

before it would get critical, using the standard 4

methodology that any other reactor would have to use, 5

which includes this stack rod, for example, they 6

calculated that when you get, and I don't remember the 7

exact number and it's proprietary, but a few feet into 8

the core, not even halfway to the core, it would reach 9

criticality.

10 As the flow progresses toward the end to 11 the top of the core, a tremendous amount of reactivity 12 gets inserted into the core and nobody has bothered to 13 analyze that condition.

14 Okay, Sandra, can you move to line 36, to 15 the top? There have been some arguments made by the 16 applicant and the staff that no mechanism exists to 17 drive the deborated downcomer water into the core, and 18 to me, they are unconvincing.

19 First and foremost, they are opinions from 20 the applicant, not calculations and not documented.

21 So, we are to the point at which designing the safety 22 of the reactor based on engineers' opinions, I don't 23 know where we're at for that now, okay. Secondly, 24 actuation of non --

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15 MEMBER KIRCHNER: Jose, this is Walt. I 1

don't want to quibble with words, but I'm going to say 2

that engineering judgment, not calculations. Clearly 3

the applicant and the staff have thought about this 4

very hard. We may have a differing view of their 5

interpretation, but I would not use the word opinion.

6 Let's give them the benefit of the doubt that good 7

engineering judgment is being applied to this issue.

8 MEMBER MARCH-LEUBA: It is undocumented, 9

unreviewed, and as far as we've been told orally by 10 these members, there are no calculations behind it.

11 I mean, we were told in the record in 12 early June that no calculation had been performed for 13 this. We were told on the record that no calculation 14 exists. This is my opinion.

15 I mean, calling it engineering judgment is 16 the same thing, but no calculation performed, no 17 calculation recorded, no calculation documented, no 18 calculation reviewed.

19 In my opinion, if you actuate any of the 20 three non-secondary systems that I talked about 21 yesterday, it would create sufficient extra pressure 22 in the top of the downcomer to push the 14 core 23 volumes of deborated water into the core, and on line 24 42 --

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16 MEMBER KIRCHNER: No, stop. Stop, Jose.

1 Remember, you prefaced this by facts, so let's stick 2

to facts. That's what's available. There is no -- we 3

haven't -- there is no way that has been demonstrated 4

for the 14 --

5 MEMBER MARCH-LEUBA: It is on --

6 (Simultaneous speaking.)

7 MEMBER KIRCHNER: -- times the core volume 8

to be instantaneously introduced to the core. So --

9 MEMBER MARCH-LEUBA: No, no, you said --

10 MEMBER KIRCHNER: And that's where we get 11 into what you're driving at, but don't --

12 MEMBER MARCH-LEUBA:

You said 13 instantaneous. I never said instantaneous. When you 14 turn in CFDS, that's 100 gpm of liquid on the top of 15 the CMV, which then drives flow positive to the left 16 on the RRV, which now raises the level on the 17 downcomer and pushes the bottom of the downcomer into 18 the riser to raise the level higher, and that 19 calculation has been performed --

20 MEMBER KIRCHNER: That's a rate-dependent 21 thing if it's driven by external forces --

22 MEMBER MARCH-LEUBA: It is --

23 MEMBER KIRCHNER: -- and it may be a U-24 tube manometer oscillation if it's driven by upsets 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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17 within the system, so that's --

1 MEMBER MARCH-LEUBA: Have you --

2 MEMBER KIRCHNER: -- available. That's 3

available, I agree with you, but it's not clear that 4

all 14 volumes go through the core.

5 MR. NGUYEN: Excuse me, Chairman, we may 6

have a factual clarification that may aid in 7

discussion.

8 MR. BORROMEO: Yeah, hi, this is Josh 9

Borromeo from the staff. The volume of deborated 10 downcomer is 14 times the volume. It's the downcomer 11 plus the containment, and that's above the RV.

12 MEMBER MARCH-LEUBA: Above the RV, okay.

13 So, and all of that water is deborated, correct, you 14 are sure?

15 MR. BORROMEO: That's what Shanlai stated 16 in his presentation yesterday.

17 MEMBER MARCH-LEUBA: All right, what is 18 your opinion?

19 MR. BORROMEO: I haven't reviewed that.

20 MEMBER MARCH-LEUBA: Okay, my opinion is 21 all of that water is deborated. The bottom line is 22 whether it includes the CMV or not. It is a lot of 23 water that you can push into the core. Even if you 24 have some mixing, you are going to flash everything.

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18 But I won't say the 14 anymore, okay, but 1

you do confirm that between downcomer and whatever is 2

on the core, on the containment above RRV, you have 3

that much volume of possibly unborated water? So, 4

where were we?

5 So, if you have -- I'm on line 42, okay?

6 So, there are four -- yes, sir?

7 MEMBER BLEY: A question. All of that 8

deborated water used to be borated --

9 MEMBER MARCH-LEUBA: Correct.

10 MEMBER BLEY: -- without putting it in the 11 flooding system.

12 MEMBER MARCH-LEUBA: Correct.

13 MEMBER BLEY: And all of that boron that 14 used to be in that water remains in the core region, 15 right, or mostly?

16 MEMBER MARCH-LEUBA: In the core and 17 riser, correct.

18 MEMBER BLEY: Yeah, so back to what Walt 19 was saying, this really is a rate problem. Depending 20 on how fast you put in the borated water, either the 21 core sees unborated water or there's mixing, and if 22 there's good mixing, and we don't know that now, it 23 will never be worse than it started if you had 24 complete mixing.

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19 MEMBER MARCH-LEUBA: It is an interesting 1

theory. You have to have complete mixing with the 2

core and all of the riser because either can 3

accumulate in the core, either accumulated in the core 4

and riser.

5 So, you will have to mix all of that 6

deborated water. You have to mix it not just with the 7

core where it's coming through, but the other 15-foot 8

of riser. It's possible. It is possible. I don't 9

see any analysis that tells me that.

10 MEMBER KIRCHNER: Yeah, so, Jose, Dennis 11 is right. It's a rate and mixing problem, and 12 depending on what upsets the status quo, that will be 13 a major factor in the rate of mixing and injection, so 14 15 MEMBER MARCH-LEUBA: Okay.

16 MEMBER KIRCHNER: It's a difficult 17 problem, as Jose said, without a lot of documentation.

18 MEMBER MARCH-LEUBA: I'll agree. I'll 19 agree with everything you said, and now but I will ask 20 you, Walt and Dennis, have you seen any calculation of 21 what --

22 (Simultaneous speaking.)

23 MEMBER KIRCHNER: -- already documented 24 it. We've also -- and it was presented in view graphs 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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20 by the applicant, and it's one of your upper bullets.

1 So, they did look at what the intrusion of clean 2

unborated water front into the core would do. And as 3

you point out --

4 MEMBER MARCH-LEUBA: No, they have not.

5 MEMBER KIRCHNER: -- by the time it 6

penetrates the core, probably just a foot-and-a-half 7

or so, I won't hang up on the exact number, you would 8

go critical and return to power again. It's in your, 9

one of your facts above, so they did --

10 (Simultaneous speaking.)

11 MEMBER KIRCHNER: -- do analysis.

12 MEMBER MARCH-LEUBA: Are you talking about 13 the MCNP calculation?

14 (No audible response.)

15 MEMBER MARCH-LEUBA: Okay, my point to all 16 of the members is --

17 MEMBER RICCARDELLA: Educate me. What is 18 MCNP?

19 MEMBER MARCH-LEUBA: MCNP is the Monte 20 Carlo --

21 MEMBER KIRCHNER: Monte Carlo, yeah, 22 neutron particular code. It's the benchmark standard, 23 Pete, in the industry. By the way, it's a Los Alamos 24 code.

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21 MEMBER RICCARDELLA: All right, thank you.

1 MEMBER MARCH-LEUBA: And that MCNP 2

calculation, it probably was extremely conservative.

3 I'll give you that.

4 So, as I said yesterday, there are four 5

non-safety grade systems, no, safety grade systems and 6

four non-safety grade systems which can inject borated 7

water in the core. Three of them put the water on top 8

of the downcomer and push the deborated water into the 9

core, okay.

10 So, if the ECCS injection line fails and 11 is not repairable, for example, if it breaks its high 12 containment, all recorded mechanism created unborated 13 core flow into the core, and not a single one of them 14 has been analyzed.

15 The SER has a very short paragraph that 16 makes a high calculation that says that the injection 17 of reactivity from this event will be roughly one 18 dollar per minute depending on whether one or two CFDS 19 pumps are started, okay, and if two CFDS pumps are 20 started, then it takes half the time, and that one 21 dollar keeps coming like the tide, okay.

22 The argument the staff makes there, and 23 this is not on the bullets, is that because it's only 24 one dollar per minute, the core will reach thermal 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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22 equilibrium with that reactivity, and that feedback 1

reactivity will compensate for the positive reactivity 2

and everything will be okay, but no calculation is 3

performed of that.

4 I mean, 20 dollars of feedback reactivity 5

is a lot when one considers that what we call the 6

power defect, which is the fuel temperature at nominal 7

conditions, it's only three dollars.

8 So, three dollars of reactivity is all the 9

feedback you get from the fuel if you reach 100 10 percent power, and we're putting 20, 25.

11 And there are other feedback mechanisms.

12 There is a super cool and there is -- and you shut 13 down maybe at.98. There are other things that you 14 can create for, and if you do the analysis, you might 15 see that you can survive it, but I have not seen any 16 analysis. You have not seen any analysis.

17 We have been told in the June full 18 committee meeting that such analysis does not exist, 19 or didn't exist in June, so this is basically what the 20 paragraph on 48 says.

21 MEMBER KIRCHNER: May I add something?

22 MEMBER MARCH-LEUBA: Yes.

23 MEMBER KIRCHNER: My concern is, having 24 looked at this very hard like you have and a lot of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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23 other people have, what we have here after ECCS 1

actuation is a depressurized system, and we have a 2

standing manometer design at that point. We've got 3

two levels, one in the core, one in the downcomer.

4 So, with the perturbation of the system, 5

for example, the containment fill and drain system 6

being actuated, as Jose says, that will come in at a 7

certain rate that a static analysis would suggest is 8

about a dollar a minute or something as the staff has 9

reported, if the system returns to power in any way, 10 it will probably then create the potential for an 11 oscillation.

12 And then it's my -- this is not fact now.

13 I'm going into kind of just judgment and experience 14 with other systems, in this kind of situation where 15 you will get oscillations driven by power, the 16 feedback with power.

17 So, that's a concern and that's something 18 to be avoided, and that doesn't seem to have been 19 addressed either even --

20 MEMBER MARCH-LEUBA: It really has. It 21 has been addressed. I mean, the Peter Yarsky white 22 paper addresses those possibilities.

23 MEMBER KIRCHNER: Well, so, anyway, go on, 24 but --

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24 MEMBER MARCH-LEUBA: Since you brought it 1

up --

2 MEMBER RICCARDELLA: But Walt, wouldn't 3

those oscillations also enhance mixing?

4 MEMBER KIRCHNER: They would.

5 MEMBER MARCH-LEUBA: Possibly.

6 MEMBER KIRCHNER: And this is where it 7

would be good to analyze whether they amplify or they 8

are self-extinguished, so to speak.

9 MEMBER RICCARDELLA: I understand. Thank 10 you.

11 MEMBER MARCH-LEUBA:

Not a

single 12 calculation exists that A,

manometer type of 13 oscillation will assist. I would claim, and I don't 14 want to waste your time, Walt, but you're not right on 15 this.

16 The creation of voids in the core that has 17 not produced any change in the manometer because it 18 doesn't change the weight of the column. The creation 19 of voids creates oscillation when you have another 20 circulation loop, and the riser is uncovered and you 21 have another --

22 MEMBER KIRCHNER: Well, I disagree, but we 23 have -- neither of us analyzed the problem.

24 MEMBER MARCH-LEUBA: Yeah, yeah.

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25 MEMBER KIRCHNER: But the potential is 1

certainly there and --

2 (Simultaneous speaking.)

3 MEMBER KIRCHNER: -- if you had a large 4

return to power, you definitely would get an 5

oscillation.

6 MEMBER MARCH-LEUBA: If it's fast and you 7

have dynamic loads, but if you are going through a 8

slow raising power like we claim it as, one dollar a 9

minute, it will be minimal. And Peter analyzed it in 10 his paper and he --

11 MEMBER KIRCHNER: I don't claim it's a 12 dollar a minute. I'm just saying the potential exists 13 for it, so it --

14 MEMBER MARCH-LEUBA: Okay.

15 MEMBER KIRCHNER: -- remains unanalyzed.

16 MEMBER MARCH-LEUBA: All right, Dennis had 17 a question.

18 MEMBER BLEY: Yeah, I had a question and 19 a comment. So far, I don't have any objection to 20 anything I've seen in the written document you have 21 before us, except I agree with Walt. I'd change 22 opinion to engineering judgment.

23 Two other minor things, I know you like 24 talking in terms of dollars, but dollars are much more 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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26 complicated than they might appear to somebody 1

listening to the discussion, and the amount of dollars 2

you get into the core region really has to do with all 3

of this flow, and possible mixing, and the rate at 4

which things are going.

5 And the other thing is you talk about 100 6

gpm, and just for everybody, that sounds like more 7

than it is. It's a couple of garden hose flow vents 8

really, but it's still 100 gpm.

9 MEMBER MARCH-LEUBA: And that's why it's 10 coming in slowly. It takes 2,000 seconds to fill the 11 whole core. I mean, what --

12 MEMBER KIRCHNER: Dennis' point though is 13 a good one for the record. These static equivalent 14 dollars of reactivity worth, this is a kinetics 15 problem. This is a dynamic problem.

16 It's not a static problem, so there is no 17 way physically to instantaneously introduce that much 18 reactivity, so it all depends, as Dennis said earlier, 19 on rate and mixing.

20 MEMBER BLEY: But the paper doesn't say 21 any of that so far. That's just been in the 22 discussion.

23 MEMBER MARCH-LEUBA: I wrote this paper 24 this morning at 7:00 a.m., okay, so let's not give it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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27 too much credit. The rate of -- if you enter CFDS, 1

there are three, two other ways that you could insert 2

deborated water into the core.

3 CFDS is the one that was addressed in the 4

SER and they calculated the flow rates, and estimated 5

that the front, if it doesn't mix, would take 2,000 6

seconds to cover the whole core, and that would result 7

in roughly one dollar a minute of reactivity 8

insertion, which is not dynamic.

9 I mean, that essentially causes static.

10 So, at every second as the ramp comes in, the reactor 11 will reach an equilibrium condition where it produces 12 sufficient feedback to compensate for however much 13 reactivity you have introduced.

14 And the only number we know for reactivity 15 is when before the front starts and the k-effective is 16 whatever, whenever the front reaches to the top and 17 you have a deborated condition in the core, that 18 number has been calculated in Chapter 4 of the FSAR 19 and is 10 pcm per ppm and is roughly 20 dollars.

20 So, at the outset, how -- whether the ramp 21 is linear, or exponential, or something in between, I 22 don't know, but all --

23 MEMBER KIRCHNER: But that, again, Jose, 24 that's a very misleading thing to go to. That's just 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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28 a static number. That's the potential maximum worth 1

if you somehow instantaneously replaced the black 2

boron concentration with a cold front in the entire 3

core. That's nice, but it's not relevant here to the 4

discussion.

5 MEMBER MARCH-LEUBA: I don't understand 6

you, Walt. Anyway, can I continue?

7 MEMBER KIRCHNER: You can continue, but, 8

you know, we really need to be careful here because 9

there's no credible mechanism to take what's 10 essentially a heavily borated core and replace it 11 instantaneously with cold deborated water. That's the 12 only way you could get to that number you're citing.

13 MEMBER MARCH-LEUBA: I --

14 MEMBER KIRCHNER: So, I don't find that 15 very relevant to this discussion.

16 MEMBER MARCH-LEUBA: Okay, Walt, let's try 17 to convince you because -- okay, so let's do a miracle 18 and we start injecting this ramp one dollar per 19 minute, we know that, slowly, and 2,000 seconds, and 20 according to you, nothing happened to the core, and 21 2,000 seconds later --

22 MEMBER KIRCHNER: No, the core is going to 23 react to that. It's not --

24 MEMBER MARCH-LEUBA: But listen --

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29 MEMBER KIRCHNER: -- going to --

1 MEMBER MARCH-LEUBA: Listen, listen, yeah.

2 MEMBER KIRCHNER: It's not going to be 3

passive.

4 MEMBER MARCH-LEUBA: Yeah, listen to my 5

question. Two thousand seconds later after all of 6

those core reactions, the whole front will have moved 7

all the way to the top of the core. What --

8 MEMBER KIRCHNER: Where will that have 9

gotten critical and returned to power long before 10 then.

11 MEMBER MARCH-LEUBA: Well, that's my 12 point. That's my point. Shandeth, you are muted.

13 That's my point, that you're never going to get here, 14 but --

15 MEMBER KIRCHNER: At this point though, 16 let's stick with the facts as you have stated. Let's 17 not do the analysis here in real time. Let's go 18 through the rest of your --

19 MEMBER MARCH-LEUBA: Walt, Walter --

20 MEMBER KIRCHNER: -- talking points.

21 MEMBER MARCH-LEUBA: You're questioning 22 basic physics, okay? If --

23 MEMBER KIRCHNER: I'm not questioning 24 them. That's what's theoretically available. I'll 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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30 agree with you.

1 MEMBER MARCH-LEUBA: Try to think --

2 MEMBER KIRCHNER: Let's move on and go 3

through this.

4 MEMBER MARCH-LEUBA: Try to think through 5

this, through the problem, okay?

6 MEMBER KIRCHNER: I've thought through it 7

as much as you have, so go through the --

8 MEMBER MARCH-LEUBA: Okay, but at least 9

let me put it on the record for all of the people that 10 are willing to listen, okay? At the end of the 2,000 11 seconds, you will have, the front will have reached 12 the top of the core, and the k-effective, the 13 calculations from NuScale tells us, will be 12,000 pcm 14 higher than it was at the beginning.

15 That's what the boron -- so if nothing 16 happened to the core and you are able to reach, the 17 front is able to reach to the top of the core, the k-18 effective will be 12,000 pcm higher, and that --

19 MEMBER KIRCHNER: What I'm trying to say 20 is I agree with you, but in a physics sense, in a real 21 system when you analyze it, that's not what will 22 happen. The core will react to that --

23 MEMBER MARCH-LEUBA: Yeah.

24 MEMBER KIRCHNER: -- and go critical 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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31 before as we -- you already -- and on the top, which 1

is out of view right now, the MCNP calculation 2

suggests that the reactor goes critical within a foot-3 and-a-half or something of the entrance of the front 4

into the core.

5 So, you're not going to get that entire 6

core deborated. It's going to go critical and return 7

to power, and then what do you think is going to 8

happen? It's going to --

9 MEMBER MARCH-LEUBA: Well, what I think is 10 going to happen is the front will continue to borate 11 because you're still pushing it. You will continue to 12 put more borated water and it will increase, and it 13 will increase the k-effective which will have to be 14 compensated by some feedback from fuel temperature 15 voids, and it will continue to go up, and up, and up.

16 At the end, if you are able, if you 17 haven't been able, all of this racing of the core 18 slowly, in equilibrium because it's going slowly, if 19 you've been able to provide feedback, at the end, you 20 will have 12,000 pcm extra caused by the boron and you 21 will have to compensate those 12,000 pcm by reactivity 22 feedback from fuel temperature and void.

23 And I'll tell you that the total 24 reactivity feedback I have available from fuel, when 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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32 I reach the 100 percent operating power temperatures, 1

is three dollars.

2 MEMBER KIRCHNER: That's a static problem 3

you're describing. This is a dynamic situation.

4 MEMBER MARCH-LEUBA: It is -- okay, my 5

argument is I don't know what happens. I haven't seen 6

a calculation that shows that it's not a problem.

7 MEMBER KIRCHNER: Good.

8 MEMBER MARCH-LEUBA: And the potential --

9 MEMBER KIRCHNER: I accept that.

10 MEMBER MARCH-LEUBA: And the potential 11 exists. These are outrageously high reactivity 12 numbers.

13 MEMBER KIRCHNER: Okay.

14 MEMBER MARCH-LEUBA: The potential exists 15 for --

16 MEMBER KIRCHNER: I agree. That's it.

17 The potential exists, that's why we're concerned, that 18 we could have a reactivity insertion accident, return 19 to power, and potential core damage. I would prefer 20 we phrase it like that and not say we have -- make 21 these statements about dollars of reactivity that are 22 available.

23 MEMBER BALLINGER: This is Ron. Let me 24 ask a metallurgical question. Once the reactor goes 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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33 critical again, don't we start adding heat?

1 PARTICIPANT: Yeah.

2 MEMBER KIRCHNER: That's my point.

3 MEMBER BALLINGER: When we start adding 4

heat, don't we mix the daylights out of things?

5 MEMBER KIRCHNER: Well, to be analyzed, 6

Ron.

7 MEMBER MARCH-LEUBA: What do you mean by 8

that? Okay, what I'm telling you is whenever -- to 9

achieve three dollars worth of reactivity feedback 10 from the fuel, you need to raise it to the temperature 11 of 100 percent operating power. That's what is called 12 the power defect, okay.

13 And if you have the fuel at the conditions 14 of 100 percent power with no flow, the calculations 15 hasn't been performed, but I can tell you the specific 16 facts for the limits are going to be difficult to meet 17 with fuel at 100 percent power conditions and no flow, 18 and this is only three dollars. You got more water 19 coming.

20 This cannot be left unanalyzed, just 21 period. It cannot be left unanalyzed. The potential 22 is to be very bad.

23 MEMBER KIRCHNER: And I think there, we 24 agree, Jose. Let's go through the rest of the paper 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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34 here.

1 MEMBER MARCH-LEUBA: All right, so --

2 MEMBER KIRCHNER: We're in the analysis 3

mode, not in the facts mode.

4 MEMBER MARCH-LEUBA: Okay, so we've said 5

that we don't have an analysis to guarantee that if 6

you start any of these three non-safety grade systems, 7

the CVCS or CFDS, we don't know if it is safe or not, 8

okay. I mean, we don't have any analysis. The 9

potential exists that it can be really bad, and we 10 don't have any analysis, okay.

11 And yesterday, the applicant said, well, 12 don't worry about it. We will start putting some 13 borated water in the downcomer and we will monitor the 14 core. When it gets critical, we'll stop putting it 15 and we'll let it mix, and then we'll let it wait for 16 an hour and then add more, and we will continue to 17 monitor --

18 MEMBER KIRCHNER: Jose, Jose, they did not 19 say that, so --

20 MEMBER MARCH-LEUBA: Yes, they said that.

21 MEMBER KIRCHNER: -- let's --

22 MEMBER MARCH-LEUBA: Yes, they said that.

23 MEMBER KIRCHNER: They said they would 24 respond with these systems that were available to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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35 them. They didn't do the scenario you just did, so 1

let's --

2 MEMBER MARCH-LEUBA: They said the only 3

instrumentation they will have available to perform 4

the recovery was the core monitoring instrumentation, 5

which is the source range, hopefully the source range 6

flux sensors, and the only time those respond is when 7

you reach criticality. So, that's what they were --

8 MEMBER KIRCHNER: That's correct.

9 MEMBER MARCH-LEUBA:

proposing 10 yesterday.

11 MEMBER KIRCHNER: Yeah.

12 MEMBER MARCH-LEUBA: Yeah, that's correct.

13 So, they will -- they say that you could -- I mean, 14 they were thinking on the fly because they don't have 15 procedures and they have not thought what you can 16 possibly do as they say, but if we keep adding borated 17 water to the downcomer, it will eventually mix because 18 when the source range detectors tell us that we're 19 critical, we'll stop. Jesus Christ, okay.

20 MEMBER KIRCHNER:

Jose, let's be 21 professional, objective, and to the facts. Let's 22 stand down.

23 MEMBER MARCH-LEUBA: These are the facts.

24 These are the facts. The proposal that we had 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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36 yesterday is we can possibly develop some procedures 1

that add borated water to the downcomer until we 2

detect criticality in the core, at which point, we'll 3

do something.

4 MEMBER KIRCHNER: Yes, so, agreed, so 5

let's investigate that further. You haven't covered 6

your instrumentation.

7 MEMBER MARCH-LEUBA: Yeah, I know. So, in 8

line 63, I wanted to make a point, a clear point that 9

even though the procedures are developed, are at the 10 COL stage, I think it's incumbent on the applicant and 11 the staff to figure out that there is one clear 12 success path to position to move forward and later to 13 modify.

14 Because whenever you have a LOCA inside 15 containment, the only possible way to fix that is to 16 take the module to the refueling station. To take the 17 module to the refueling station, you have to be in 18 Mode 4 where you are requested to have something like 19 1,700 ppm of boron, which you don't, and you need to 20 add boron.

21 And any way you add borated water, if you 22 have a break on the injection line, it creates this 23 possibility of recriticality. So, I don't see a clear 24 success path to transition to Mode 4.

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37 MEMBER KIRCHNER: I do. I thought we were 1

doing facts. I withheld my own. I have a suggestion 2

to avoid this, but I thought we were doing facts and 3

not --

4 MEMBER MARCH-LEUBA: Okay, it is fantastic 5

that you have some, and let me use the word again, 6

opinion, or engineering judgment. I want to see a 7

final safety analysis report written under Appendix B 8

requirements that tells me what they're going to do.

9 MEMBER KIRCHNER: Okay, right. So, let me 10 interject it then because I withheld earlier. Look, 11 the problem, as we're agreed, we feel -- once again, 12 I'm repeating myself. We feel with the riser holes, 13 they have solved the issues of deborating the 14 downcomer in the DHRS. That's for the record, the 15 decay heat removal system mode.

16 The analysis by the applicant and the 17 staff, I think, are sound. A figure of merit was used 18 by the staff on critical boron concentration at 72 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br />, and they showed what, in my engineering 20 judgment, not my opinion, is a sufficient margin to 21 critical boron concentration.

22 Now, we're on the ECCS side of the 23 scenarios. I had both the applicant and the staff 24 estimate that the deborating of the downcomer would 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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38 take hours. It probably would happen faster than the 1

envelope of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

2 So, does one leave the system in this 3

passive mode or does one intervene? I suspect that 4

one can make a calculation just like was done for the 5

decay heat removal side of the equation and look at 6

the time that is available before, with margin, like 7

a 200 ppm equivalent at beginning of life, maybe 100 8

ppm margin again at middle of cycle.

9 Calculate what the time is to that point 10 and then just institute a tech spec that says you have 11 insufficient margin and you intervene. If they 12 intervene early, they can get out of this dilemma. If 13 they leave it passively --

14 (Simultaneous speaking.)

15 MEMBER KIRCHNER: -- for a long time, then 16 you're exactly right. Then the, as you once put it 17 very eloquently, it's a very delicate set of 18 operations to get out of the fix you're in. So, I do 19 believe there is a fix, and I've suggested this 20 before.

21 I don't know if tech specs is the way you 22 accomplish this, but you have done the analysis, and 23 they have done analysis, and you know when you have 24 insufficient margin in the downcomer in terms of --

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39 versus critical boron concentration, and one 1

intervenes.

2 And if one intervenes early enough, then 3

we don't have this potential of inserting this cold 4

front of deborated water in, a potential reactivity 5

insertion accident and potential core damage. So --

6 MEMBER MARCH-LEUBA: And Walt --

7 MEMBER KIRCHNER: -- that's my fix.

8 MEMBER MARCH-LEUBA: Yeah, I see. I 9

understand what you're saying. I have two questions 10 for you. First, where can I -- in which part of the 11 SER would I find the review of that procedure? That 12 procedure does not exist, right?

13 MEMBER KIRCHNER: No, it doesn't exist.

14 Like I said, now I'm going beyond facts to solutions.

15 MEMBER MARCH-LEUBA: And question two is 16 what safety-grade power would you be using to do that?

17 Okay, I'm sorry I was facetious with that. I have a 18 better solution, by the way.

19 MEMBER KIRCHNER: They do have a highly 20 reliable electrical power supply. We've reviewed 21 that.

22 MEMBER MARCH-LEUBA: So --

23 MEMBER KIRCHNER: The options exist for 24 them to intervene.

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40 MEMBER MARCH-LEUBA: And AC power will 1

likely exist and they have DC generators, but those 2

are not the rules. I mean, if it's important to 3

safety, it has to be safety grade, and we don't --

4 we're run analysis with what they say is safety grade, 5

and it's not safety-grade power to actuate any of this 6

equipment.

7 CHAIR SUNSERI: Walt --

8 MEMBER MARCH-LEUBA: You can only actuate 9

them if they are bad for you. If they are good for 10 you, you cannot take credit for it.

11 MEMBER KIRCHNER: Well, let's get out of 12 Chapter --

13 CHAIR SUNSERI: Walt, Walt, Walt, this is 14 Matt. Walt and Jose, I want to just know when are we 15

-- we need to wrap up the --

16 MEMBER MARCH-LEUBA: Okay.

17 CHAIR SUNSERI: -- the discussion from 18 Jose and allow other members to speak on this. And 19 I'm not trying to cut you off, but I'm starting to 20 hear circular discussions here, and we're going around 21 and around on the same old stuff.

22 And I don't mean to be so casual with this 23 important stuff, but I'd like to hear what other 24 members have to say about this.

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41 MEMBER MARCH-LEUBA: Can I finish this?

1 I'm almost done --

2 CHAIR SUNSERI: Yeah, yeah.

3 MEMBER MARCH-LEUBA: -- if Walt doesn't 4

interrupt me, okay.

5 CHAIR SUNSERI: Yeah.

6 MEMBER MARCH-LEUBA: So, instrumentation, 7

bottom line, there is no instrumentation that could 8

measure boron redistribution, period. There is a 9

single point where you can measure boron concentration 10 and it's not likely to work when you are --

11 I have seen no evidence that it works when 12 you are in post-ECCS conditions, so the operator is 13 flying blind, okay.

14 I find the suggestion by the applicant 15 yesterday that they could use the source range flux 16 detectors to detect criticality and therefore assume 17 what the boron distribution is extremely dangerous.

18 Sandra, can you move to the next section?

19 And I thought this was not going to be an open 20 session. Well, positive void coefficient you heard me 21 say before nobody knows what the void coefficient is 22 when this front comes in.

23 I can argue that there is a critical boron 24 concentration above which it is positive. We know the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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42 void coefficient is positive for concentrations larger 1

than 1,200 to 1,400 ppm. I cannot say the void 2

coefficient is negative when this front comes in, and 3

I have not seen an evaluation and I think that is 4

negligent. Risk evaluation --

5 MEMBER KIRCHNER: Jose, Jose, since you've 6

used static reference points, I'll use one. The cold 7

front coming in will have a negative void coefficient.

8 It's only the boron, presence of boron that makes void 9

coefficient positive, and that's only under certain 10 circumstances.

11 MEMBER MARCH-LEUBA: Can you point me to 12 the calculation that shows that it's negative?

13 MEMBER KIRCHNER: Jose, you've made the 14 point about the availability of calculations enough 15 times. I'm just saying that cold water in an under-16 moderated core like this, forget there's any boron 17 present, is a negative void coefficient.

18 MEMBER MARCH-LEUBA: And I claim the 19 contrary when you have a highly heterogeneous core 20 with boron on top, but let's not waste time with --

21 (Simultaneous speaking.)

22 MEMBER KIRCHNER: I said -- you're not 23 listening to me. I said when you have deborated 24 water, the void coefficient is negative.

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43 MEMBER MARCH-LEUBA: You don't have 1

deborated water. You have half of the core is 2

deborated and half of the core is highly borated, and 3

half of the --

4 MEMBER KIRCHNER: I understand that.

5 MEMBER MARCH-LEUBA: -- core happens to be 6

on top. Okay, and so I just haven't seen a 7

calculation, okay? I haven't seen a calculation, so 8

we don't know whether it's positive or negative. So, 9

taking credit for negative reactivity feedback when 10 that one dollar per minute ramp comes in is 11 unsupported by facts, period.

12 Risk evaluation, the applicant chose not 13 to do a risk analysis for deboration conditions, 14 period. I mean, and in the diverging opinion that we 15 heard yesterday, a cognizant staff engineer that has 16 been reviewing this from the beginning thinks that the 17 core damage frequency is seven orders, up to seven 18 orders of magnitude larger than what is advertised.

19 That's what he thinks, and he has some 20 calculation, hand calculation of that. I just cannot 21 comprehend why this risk was not part of the scope of 22 the PRA.

23 What we cannot say, and I thought we were 24 going to be doing this in a closed session among ACRS 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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44 members, but if they have drilled four holes at the 1

RRV location, you will not have a boron deboration 2

issue, and you will not have to do all of these 3

calculations and you won't have to justify anything.

4 And it has minimal impact on anything 5

else, so I just cannot comprehend why they didn't do 6

it and that's what's driving me crazy.

7 So, my recommendation, right now, we don't 8

have any calculation whatsoever that suggests that 9

this situation is safe. Deborating the downcomer, 10 parking up to 20 dollars worth of reactivity at the 11 core inlet waiting for perturbation is, frankly, 12 irresponsible.

13 So, my recommendation is the staff should 14 care about the downcomer deboration and not certify it 15 as safe because they don't have the analysis to 16 justify that it is safe. Okay, I'm done. Matt, your 17 turn.

18 MEMBER KIRCHNER: Thank you, Jose. Thank 19 you very much actually, and for the spirited 20 discussion. I think I would like to turn, Mr.

21 Chairman, next to Dave Petti, who has given this also 22 considerable thought. And Dave, if you would like to 23 use the viewgraph you prepared, I think the staff is 24 ready to put it up.

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45 MEMBER PETTI: Sandra, please put it up.

1 So I tried to categorize all the different things 2

we've heard, and we hear in words. And I'm a visual 3

person so I like these sorts of things because it 4

helps my thinking.

5 MEMBER KIRCHNER: Dave? Dave --

6 MEMBER PETTI: Yes.

7 MEMBER KIRCHNER:

pardon my 8

interruption. Can you speak more directly into your 9

microphone? We're getting a weak audio signal.

10 MEMBER PETTI: Is this better? Can you 11 hear me?

12 MEMBER KIRCHNER: Somewhat. Just a little 13 more --

14 MEMBER PETTI: Oh, I know what the problem 15 is, hold on. It's a fan from the other computer 16 drowning out this. Give me a minute to move my 17 computer around. Is this better?

18 MEMBER KIRCHNER: Yes.

19 MEMBER PETTI: Okay. So, on the top left 20 of the figure are the two event sequence families, if 21 you will. Those associated with decay heat removal 22 and then ECCS.

23 Come down from the decay heat removal by 24 show in yellow what the changes were in the design, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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46 the setpoint changes in the riser holes that we talked 1

about, the two analytical bounding methods that were 2

presented by NuScale and confirmed by the Staff. And 3

so, that's sort of okay for those events.

4 If you come down for the ECCS or LOCA 5

event, before ECCS actuation, the setpoint changes in 6

the riser holes had to do the same thing. The real 7

question, as we've heard already, is what happens 8

after actuation of the ECCS and the deboration.

9 I just want people to realize that the 10 results that were presented by NuScale in the March 11 meeting were DBA calculations using conservative rule 12 sets. We heard about it in the March 2020 13 Subcommittee.

14 And those were okay, but they really 15 weren't addressing this issue, they were really 16 looking at the core and potential return to power.

17 And so, as is typical in DBA calculations, a bunch of 18 conservative assumptions were made that are highly 19 stylized in terms of when you think about what's 20 actually, what actually would happen versus what 21 happens in a stylized step, Chapter 15 analysis.

22 And the real question that came up as a 23 result of that, these recovery actions path of 24 strategy. And we'll come back to that.

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47 But after actuation there's a whole series 1

of potential beyond design basis events that one needs 2

to consider the influence of the down, of deblowing 3

the downcomer.

4 The NRC Staff, Dr. Yarsky, put together a 5

very nice White Paper I thought that did exactly what 6

Dennis and we were talking about earlier about looking 7

across the spectrum of events. Are there any events, 8

how could we have water get into the core, deborated 9

water get into the core.

10 And he systematically went through all of 11 the different options. And he used engineering 12 judgement which I think is a good thing here.

13 But as we heard more about his analysis 14 and his engineering judgment, what struck me was that 15 a simple one-dimensional RELAP calculation with point 16 kinetics ain't going to get you there. And I'm 17 worried that intuition, lots of us have intuitions 18 based on code calculations.

19 And those intuitions can be long because 20 this is not like other reactors. We heard about the 21 mixing and the oscillatory flow behavior, how much and 22 how fast can the downcomer water come in.

23 There are all of these kinetically 24 activity issues. This is not a simple analysis. If 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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48 it were a simple analysis I think someone would have 1

been able to develop some recovery actions that need 2

calculations to help guide what it is you're going to 3

do.

4 And so, that multi-dimensional analysis is 5

a 3-D, probably a RELAP-5 3-D or TRACE 3-D calculation 6

and I think it's probably space time kinetics.

7 I do appreciate the verbal discussion we 8

had yesterday with Dr. Yarsky where he, in the White 9

Paper talked about all these things and took what I 10 call the flow mixing approach and walked through how 11 we thought things would evolve.

12 Then verbally we went into this sort of 13 other end of the spectrum. Okay, let's assume we have 14 a stratified core with a very black area with the 15 borated water and unborated water coming in from the 16 bottom.

17 And he talked about the physics effects, 18 trying to look at it from both extremes. So the 19 question is, when you add this, when you boil this all 20 down, where are we really. I think it's hard to say.

21 I appreciate the comments about having to 22 do an analysis, but I don't think it's easy. This is 23 probably pushing nuclear codes more in a way that have 24 not been used in the past because of the uniqueness of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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49 the system.

1 And so, getting to those recovery actions 2

is something that can't happen at the DCA stage but is 3

going to have to happen at the COL stage. And it's 4

going to take some calculations.

5 So that's, it's the red box where all the 6

discussion was. And we got a lot of different 7

opinions and engineering judgment on what actually 8

will happen there.

9 I'm not convinced that if three-10 dimensional calculations are done that it just doesn't 11 confuse us on a higher plain, if you will. Because 12 people will argue that, well, it's a co-calculation 13 and I don't like this co-calculation for this reason, 14 I don't like it for that reason.

15 I appreciate Dr. Yarsky's analysis because 16 it was at a higher level and tried to stick with first 17 principles in the approach. I found my profession as 18 I found the analytical, a bounding method showed 19 NuScale refreshing.

20 And so, that was just sort of where I 21 thought we ended up. And so I thought this sort of 22 captured it, tried to capture it, to know where the 23 problem is and where the problem is not.

24 MEMBER MARCH-LEUBA: Dave, I have --

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50 MEMBER KIRCHNER: Thank you, Dave.

1 MEMBER MARCH-LEUBA: -- a couple of 2

comments. Guys, go ahead, Walt.

3 MEMBER KIRCHNER: Yes, go ahead.

4 MEMBER MARCH-LEUBA: Everything I've been 5

talking about is a purple box on the top corner. I 6

didn't even know anything to be done to DBA.

7 So, everything I went through, obviously 8

I did not do a good job of communicating, is --

9 MEMBER KIRCHNER: No, Jose, I think you 10 did.

11 MEMBER MARCH-LEUBA: Well --

12 MEMBER KIRCHNER: I agree with you, Jose, 13 that we don't need to go beyond DBA space to have the 14 purple box concerns.

15 MEMBER PETTI: Right.

16 MEMBER MARCH-LEUBA: Yes.

17 MEMBER PETTI: Because I think what my 18 point is, that you can't use the rule sets of DBA to 19 develop those actions, you're going to have to go best 20 estimate which is kind of DBA --

21 MEMBER KIRCHNER: I agree, Dave.

22 MEMBER PETTI: So what I would have done 23 last night, I thought about this, is put a dotted line 24 from the red box up to the recovery because that's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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51 what's going to inform recovery because you need the 1

actual response of the core not the stylized DBA 2

response, if you will.

3 MEMBER MARCH-LEUBA: Right. But my 4

question to you, Dave, is what, number one is 5

establish a fact. Do you believe that after ECCS is 6

actuated the downcomer will deborate?

7 MEMBER PETTI: Yes.

8 MEMBER MARCH-LEUBA: And it will do so 9

within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />?

10 MEMBER PETTI: Yes.

11 MEMBER MARCH-LEUBA: So I hear a yes. And 12 then, what confidence do you have, the operator can 13 move into Mode 4 to start the recovery from the 14 accident.

15 What basis do you have to have confidence 16 that once you put yourself in this, first of all its 17 unstable, but precarious condition where you have all, 18 nothing but the water in the core, what confidence do 19 you have that the operator can move into Mode 4 and 5?

20 I have no confidence. I mean, I think, my 21 gut feeling, we figure out a way to do it. I just 22 have no documentary evidence that it can do that.

23 MEMBER PETTI: So to me, this gets down to 24 a question of how much do you need to make the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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52 assessment. Does Dr. Yarsky's approach cover all the 1

basis and provide reasonable assurance.

2 MEMBER MARCH-LEUBA: Well --

3 MEMBER PETTI: Absolutely. Because when 4

I hear calculations, my mind thinks you're looking for 5

a much greater level of assurance than I, as I have 6

understood reasonable assurance.

7 MEMBER MARCH-LEUBA: We were captured 8

under the discussion yesterday with Dr. Yarsky. But 9

I still disagree with the statement in the SER on the 10 statement that Walt makes, that if you put $1 per 11 minute of the activity with as much as 20 behind it, 12 that because it's slow miraculous feedback will 13 happen. And it will compensate for all those, 14 eventually $20 when you reach it in 20 minutes.

15 I strongly disagree with that standard, I 16 did. Because it's, basically it's completely 17 baseless. He does not say that that's about to 18 happen.

19 What he says is that there won't be a 20 prompt criticality event, which will immediately cause 21 fuel failure. But he does not make a study of, do you 22 put in dollars and dollars in there, how much feedback 23 do you need to compensate for it.

24 Especially because he doesn't know where 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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53 the word coefficient is. Nobody has calculated it.

1 He doesn't know what coefficient is, nobody has 2

calculated it.

3 CHAIR SUNSERI: This is Matt. And I know 4

that there will be probably all kinds of reasons why 5

I'm not right on this but, at least in my mind, from 6

a operating perspective, I mean, the assumption here 7

is that you're putting on to be a course led trained 8

system or whatever.

9 And you're just kind of letting run at 100 10 gallons per minute. And --

11 (Simultaneous speaking.)

12 CHAIR SUNSERI: So, can you hear me now?

13 MEMBER KIRCHNER: Go ahead, Matt.

14 CHAIR SUNSERI: Okay. So, I mean, there 15 is other ways to do that just besides turning on the 16 system and letting it run.

17 And I disagree with the fact that the 18 source range instrument if they're not going to be 19 that useful. I mean, we use them all the time to 20 monitor the approach to criticality.

21 So, I mean, why couldn't the operator turn 22 on the DRS, or whatever the system is, the flooding 23 system, monitor source range instrument, look for flex 24 doubling. If they think there is an approach to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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54 criticality, turn on the system and let it mix a 1

little bit. There are ways to recover this without 2

just turning it on and letting it run.

3 MEMBER BALLINGER: Well, yes, this is Ron.

4 I've been struggling with this for weeks now. And I'm 5

listening to people argue over, it's 100 gallons a 6

minute, if it's 50 gallons a minute, if it's this many 7

pcm or that many pcm.

8 The red box, at least in the metallurgist 9

outlook, is a quagmire, right. And we're reduced to 10 the point where it's the purple box that's important 11 in cutting off the head of the snake, which is the red 12 box.

13 And that is, now we're in to, we have a 14 tendency sometimes, applicants do, have a tendency to 15 say, we're going to push this off to the COL stage.

16 And that's all well and good.

17 It's just that what I worry about is that 18 when you say, in this particular case, that we push it 19 off to the COL stage, we need to be sure that in fact 20 if we do push it off to the COL stage that there 21 actually is a path to recovery considering human 22 reliability, now we're into all of that sort of 23 subjective stuff.

24 But it's important in this case, unlike 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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55 other DCAs that we've seen, or at least that I've 1

seen, we're pushing certain things off to the COL 2

stage. You can do it because there's a pretty good, 3

there's a pretty good reasoning that in fact at the 4

COL stage it will be solved.

5 So my question would be, is it possible to 6

cut the head off of the red box snake by the recovery 7

actions path and can we assure ourselves that if that 8

is the COL stage that somebody wants to build one of 9

these things doesn't end up getting themselves in a 10 box with no exit.

11 You know, and that's a very simplistic 12 kind of discussion, but anyway.

13 MEMBER PETTI: So, Ron, my answer, which 14 is in some text that I've, well, that guys I think got 15 a copy of, is that you have to go into the quagmire to 16 inform the purple box. Because right now, any other 17 approach you're not going to know.

18 And so while we would like to have a 19 strategy, not necessarily a defined path or action, 20 it's called wildly overcoming a strategy, it's under-21 informed right now until you, unless you can get into 22 the red box in some way.

23 MEMBER BALLINGER: Yes. I mean, I have no 24 doubt that we're going to get into the red box.

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56 MEMBER PETTI: Yes. I mean, I'm with you, 1

I'd like to --

2 MEMBER BALLINGER: My question is --

3 MEMBER PETTI: -- that.

4 MEMBER BALLINGER: My question is, I guess 5

I'm thinking along the same lines as Matt. That we 6

got to be sure that if we get into the red box and 7

never get out of the red box, to anybody's 8

satisfaction, to our satisfaction, that the recovery 9

path is still an option that will work. And that it 10 will work in a reliable fashion.

11 I know I keep saying PRA and human 12 reliability, but that's where we end up being.

13 MEMBER RICCARDELLA: Okay, I agree. This 14 is --

15 (Simultaneously speaking.)

16 MEMBER RICCARDELLA: I agree with Dave 17 Petti that we need to eventually, we need to get into 18 the red box and do that analysis to inform the purple 19 box. But I guess the question is, how much of that is 20 really necessary at the DCA stage.

21 They're not going to do the procedures 22 that are the recovery actions until the COL stage.

23 And there's plenty of time to do all of the analyses 24 in the red box between the DCA and the COL stage.

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57 That's my opinion.

1 MEMBER DIMITRIJEVIC: Okay, I would like 2

to give some Chapter 19 perspective from the risk.

3 Can I do this, will everybody --

4 CHAIR SUNSERI: Go ahead, Vesna.

5 MEMBER RICCARDELLA: Okay. This is, I was 6

going to write this but I was hoping that I will have 7

a chance to ask Pete some questions.

8 So from the, but since I don't, and I did 9

not even provide the comment to describe that, but I 10 have it in front of me.

11 The PRA needs a clear, for PRA is very 12 good with facts because we need a pretty clear 13 definition, you know, to develop model, what's 14 happening.

15 So we need to understand process in order 16 to, process is not in the pH sense, like you guys are 17 discussing but is what is actually happening, which 18 could produce those power exclusion. In what we call 19 scenarios, right.

20 So, so the facts is that at this moment 21 I'm not sure because I heard the two contradictory 22 presentations. One is to say, and Pete did his study 23 assuming that we have a stuck rod. Right.

24 Is the version opinion assume that this 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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58 can also could without stuck rods. So, that's a very 1

important question from this perspective because stuck 2

rod put everything in the low frequencies.

3 So, I don't know, do we, I don't, at least 4

I don't in this moment know the issue is, prolong ECCS 5

injection issue without stuck rod.

6 MEMBER KIRCHNER: Vesna, I think, and Jose 7

will join in, I think you can have this potential 8

return to criticality without the stuck rod.

9 MEMBER DIMITRIJEVIC: Okay, that's, I just 10 want to say fact is that I don't know that for sure 11 because I heard the two different, I mean, analyzing 12 is, by the Dr. Yarsky, was clearly done for small-13 break LOCAs with stuck rod.

14 All right, so that's my first question.

15 And very important from this perspective.

16 The second question is, main point here is 17 connected, it can happen with the delay ECCS injection 18 and also with prolong ECCS injection. Right?

19 And maybe stuck rod rule is different for 20 those two, I don't know.

21 In any case, in both cases, I mean, it 22 could be different events and it could be different 23 assumptions, but I don't really have any good feeling 24 about time brackets we are talking. Because sometimes 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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59 I hear less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, sometimes I hear 14 days 1

for prolong ECCS injection.

2 And it is a very important to know, I know 3

we cannot really determine the time because it's 4

depending of entering conditions that we have nearly 5

some feeling of what time bracket we are discussing.

6 So, I don't think that this is answered in this 7

moment, Pete, so I don't think I know this fact.

8 The second thing is, at least I am telling 9

what facts I don't know. Maybe some of the Committee 10 feels different about this.

11 Then we discuss CVCS or CFDS non-safety 12 injection. Obviously we can have delay CVCS and 13 potential CFDS to delay ECCS injection. And those are 14 very likely to happen because if ECCS does not 15 actuate, the operator help to actuate one of those 16 systems, CVCS in the normal LOCA and CFDS if you have 17 a LOCA outside of the containment.

18 I am not sure that, is it clear to me, is 19 that the issue or not. In the PRA presentation it was 20 defined not as the issued. That's one of the 21 scenarios very common in PRA.

22 And then when it comes to prolong ECCS 23 injection, where they stated that they don't see the 24 way to bring the water into the core, there was, in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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60 this divergent opinion there was the estimate or some 1

probability. That probability is very important.

2 The way to do, to bring this water, the 3

way to actuate those system there have to be some way 4

that something else fails to indicate to the operator.

5 So he doesn't even know.

6 We did not even see any discussion of the 7

way, how that reactor cool. And then when it comes to 8

recovery, all intervention, all, we really have not 9

any discussion on the instrumentation or what actually 10 needs to be done. And that's the fact.

11 So we know very little about that, put the 12 human error out of commission or all recovery from 13 this state. And that's definitely fact because I 14 didn't see anything specific on this. That covers 15 instrumentation with Jose.

16 So the facts I am missing is the, well, is 17 the stuck rod related both to delay and prolong ECCS 18 injection, what are the time brackets in these things, 19 CVCS delay injection or the injection after prolong, 20 the ECCS operation, which will be out of commission, 21 and then what type of recoveries, with what indication 22 we are talking about. So this is the summary of what 23 I feel I am missing in order to make Chapter 19 24 conclusions.

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61 MEMBER KIRCHNER: Thank you, Vesna.

1 Colleagues? Dennis, do you want to comment?

2 MEMBER BLEY: Well, sure. I look at 3

Dave's chart and I got to, I quibble with some parts 4

of it but the end points, the purple box and the red 5

box is clearly where we end up.

6 But I got back to Jose's presentation of 7

facts. And mostly I agree with those facts. There's 8

a couple of places where I think we polish the words 9

a bit.

10 But the place he ends up, Jose's analysis, 11 if you'll forgive me, is kind of like the Staffs.

12 It's an analysis without any analysis. And it's 13 expert judgement as well.

14 Oh, and it's a bounding case, I agree with 15 that. And I think that's sufficient to say this needs 16 to be dug into further.

17 The idea of making it a carve out doesn't 18 bother me. The idea of doing that helps because we'd 19 include the development of recovery actions.

20 And my problem, like I think most 21 everybody else's is, the documentation saying, this 22 remains a problem, isn't in the FSAR in way that makes 23 it clear. And the documentation that this really 24 needs to be a high priority for development of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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62 procedures and recovery actions is also not in a clear 1

way in the FSAR.

2 So I think bringing it up in our letter 3

is, either as a carve out or some other way to make 4

sure it gets covered before they build one of these 5

things I think is important.

6 MEMBER BALLINGER: Yes. This is Ron.

7 MEMBER BLEY: Thank you guys.

8 MEMBER BALLINGER: I think Dennis has got 9

it. The purple box is going to be what we end up in.

10 The red box is great if you're a lawyer, but at some 11 point we are going to get to the point where it's your 12 PhD arguing with my PhD.

13 And without very, very, very extensive 14 analysis, which may actually not be possible, to the 15 degree that it needs to be done, the FSAR or whatever 16 document they have really needs to be very clear about 17 what Dennis is talking about. Because in thinking 18 through what you put in that, you have to, in your 19 mind, believe that there is a recovery path.

20 Again, I'm told that Occam was not a 21 metallurgist, but I thought I saw him in freshman 22 chemistry.

23 MEMBER KIRCHNER: Thank you, Ron. Other 24 Members of the Committee?

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63 MEMBER REMPE: So, this is Joy. And I 1

tend to agree with what Dennis had said. And I have 2

a small nit.

3 And I checked the DCA to make sure I'm not 4

saying something proprietary, but in things I've seen 5

from Jose, as well as what I see Dave, it wasn't just 6

setpoint changes they actually do have a different 7

mechanism now too for initiating ECCS. Which I find 8

to be much more reliable and I'm very pleased to have 9

seen. And I hope that we can capture that.

10 But I didn't mention it earlier but there 11 were like many comments made in what Jose had said 12 that I hope we can capture, he's captured that I think 13 would make it easier to go forward with the letter 14 writing. Because there's only a couple of places 15 where we really need to be changed.

16 I really hate to see this as a carve out 17 but I don't see other ways to do it unless somebody 18 wants to change something.

19 MEMBER BALLINGER: This is Ron, one last 20 thing. I think I need to remember that we're talking 21 about Chapter 15 and we're talking about, basically 22 beyond design basis. And just need to remember that 23 I think.

24 (Simultaneous speaking.)

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64 MEMBER MARCH-LEUBA: Sorry --

1 MEMBER KIRCHNER: Ron, I don't think we're 2

beyond design basis, we're in the AOO design basis 3

space when we get to the purple box.

4 MEMBER BALLINGER: Got it. Got it, okay.

5 But we're still in Chapter 15?

6 MEMBER KIRCHNER: Well, or coming out of 7

Chapter 15 with a successful glide path.

8 MEMBER BALLINGER: Right. Yes. Yes, 9

indeed.

10 MEMBER PETTI: Right. And I think in my 11 opinion the key rule is that the rule set and the 12 codes you use to demonstrate compliance in Chapter 15 13 is going to help you get the purple box. Because you 14 need to know the actual response to the plant. Which 15 means you got to go into your best estimate tools, 16 which are typically BDDA.

17 MEMBER BALLINGER: Yes. Yes.

18 MEMBER PETTI: That's what I meant to say.

19 I mean --

20 MEMBER BALLINGER: Yes.

21 MEMBER PETTI: -- not perfectly.

22 MEMBER BALLINGER: Yes. But my question 23 is, from the conversation I've heard so far, does 24 anybody really believe that no matter how good our 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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65 best estimate tools are, are they adequate for this 1

task?

2 MEMBER KIRCHNER: Oh, that's a, I hate to 3

take up the defense of that but I will. This is Walt 4

Kirchner for the record.

5 Yes, there's a tool set that can be 6

applied. We do have very good systems, analysis 7

codes, whether it's TRACE or RELAP, that can do the 8

kind of multi-dimensional core treatment where there's 9

mixing and there are issues related to that, as well 10 as mixing coming into the core.

11 We have CFD tools that are at one's 12 disposal, if you want to look at boron concentrations.

13 And we have reactor kinetics and neutronics codes that 14 are, I think, up to the task.

15 The biggest challenge for most of the 16 systems codes, Ron, is that because of numerical 17 diffusion boron is difficult to account for 18 accurately. So if you remember that both the 19 presentations by the applicant and the staff review 20 and their work, a lot of the boron estimates are being 21 done as side calculations.

22 MEMBER BALLINGER: Right. Yes, I do, I 23 remember that.

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66 tool set is there. Certainly MCNP, for example, was 1

mentioned earlier.

2 That's a static code. But you can do 3

extraordinarily good analysis --

4 MEMBER BALLINGER: Okay.

5 MEMBER KIRCHNER: -- of K effective with 6

that.

7 MEMBER BALLINGER: So, what you're saying 8

is --

9 MEMBER KIRCHNER: As Jose pointed out --

10 MEMBER BALLINGER: What you're saying is 11 there is a, that there would be a positive outcome.

12 MEMBER REMPE: So, Walt, I --

13 MEMBER KIRCHNER: I think so.

14 MEMBER REMPE: -- validate those codes for 15 this type of situation. Do you think --

16 MEMBER KIRCHNER: Well, that's where I was 17 going.

18 MEMBER REMPE: Okay.

19 MEMBER KIRCHNER: The problem right now 20 is, and again, the Applicant and the Staff pointed 21 this out, is that when you, you add the boron 22 tracking, so to speak, into the equation, that's the 23 part that's not well validated.

24 MEMBER BLEY: Walt, could I --

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67 MEMBER KIRCHNER: Tool set, like Peter, 1

you know, Peter could, well, he's not, we shouldn't 2

turn to Peter here, but I think there's a basic tool 3

set that will allow you to bound the problem.

4 MEMBER BALLINGER: But is this a short-5 term, aka, a year problem or is it --

6 MEMBER KIRCHNER: No, these are --

7 MEMBER BALLINGER: -- a decade problem?

8 MEMBER KIRCHNER: You have to setup an 9

input model, you have to check that, you got, these 10 are, you know, some of it could be done in the 11 relatively short-term, I believe. I'm talking months.

12 Obviously, some side calculations have 13 been done in the intervening past months. So there is 14 a, what I would say, I would characterize it, there's 15 a basic tool set available that would allow you to 16 frame and probably bound the problem for purposes of 17 the purple box there on the top.

18 MEMBER BALLINGER: Okay, good.

19 MEMBER BLEY: Walt, can I ask a --

20 MEMBER KIRCHNER: Go ahead.

21 MEMBER BLEY: I'm asking a question or 22 just presenting an argument. I don't know those tools 23 very well but I know that if you try to design a 24 system that would run as a coherent front up through 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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68 the reactor of this water you'd play hell making it 1

work.

2 But this really is a situation that's very 3

sarcastic. I think every time you did it, if you were 4

doing experiments, it would look different. Now, how 5

different I don't know. And I don't know if these 6

tools are bounded. I think that would be a good 7

thing.

8 We're not in the role of presenting 9

solutions here. And we probably shouldn't do it. I 10 like Jose's ideas of a few more holes. But then they 11 probably looked at that, and maybe in their 12 calculations they found a problem with putting holes 13 down, though I don't know what it would be.

14 But I don't think we're planning to do 15 that, right?

16 MEMBER MARCH-LEUBA: I haven't heard 17 anything from the Applicant on that, Brian, to do 18 that.

19 MEMBER RICCARDELLA: I think, you know, 20 those holes would be in the core region. There might 21 be some complexities there where you're getting flow 22 through them during normal operation.

23 MEMBER KIRCHNER: No, no, it would be 24 above the core, Pete.

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69 MEMBER RICCARDELLA: Really?

1 MEMBER KIRCHNER: If you --

2 MEMBER RICCARDELLA: Yes, I thought the 3

RRVs were --

4 MEMBER KIRCHNER: No, you can put them --

5 MEMBER RICCARDELLA: -- right on top of 6

the core.

7 MEMBER KIRCHNER: Well, the design, this 8

is a nice design. So if you look at things, what they 9

did was, they made sure that any penetrations of the 10 containment and into the reactor vessel boundary were 11 always above the core level.

12 So you wouldn't put holes below the core 13 level, you would put them upper, at the lower steam 14 generator level.

15 MEMBER RICCARDELLA: So you say there's 16 room --

17 MEMBER KIRCHNER: Or as Jose said --

18 MEMBER RICCARDELLA: -- between top, 19 between top of fuel and --

20 MEMBER KIRCHNER: Probably just above the 21 RRVs.

22 MEMBER RICCARDELLA: What? Jose said --

23 MEMBER KIRCHNER: Just above the RRVs.

24 MEMBER RICCARDELLA: -- below the RRVs, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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70 right?

1 MEMBER MARCH-LEUBA: Yes. I said it has 2

to be there. They will have to be below the lowest 3

level, water level that you would expect. Which is at 4

or around the RRVs, which is roughly ten feet above 5

the core.

6 MEMBER RICCARDELLA: Oh, I didn't realize 7

there was that much room.

8 MEMBER MARCH-LEUBA: Yes.

9 MEMBER REMPE: So, I've not heard anyone 10 from the ACRS say the SER should be issued as is.

11 We're saying doing a carve out. Everyone has kind of 12 said something is missing.

13 Add a true statement is there a Member 14 that's not yet spoken that feels like it's just fine?

15 CHAIR SUNSERI: I just don't know the --

16 (Simultaneous speaking.)

17 CHAIR SUNSERI: -- yet.

18 MEMBER REMPE: I didn't hear, I heard two 19 responses.

20 CHAIR SUNSERI: Go ahead, Dave.

21 MEMBER PETTI: I don't know that we're 22 there yet, one way or the other.

23 MEMBER REMPE: Even your, Dave, has said, 24 hey, there is some things that are, you know, going to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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71 be complicated in the future. Are you still say, yes, 1

maybe they could issue it and they don't need a carve 2

out or they don't need something else. You're okay 3

with the SE?

4 MEMBER PETTI: What I'm saying is, to get 5

to the purple box, you can't get there today.

6 MEMBER REMPE: So that kind of sounds like 7

the SE, which kind of says go ahead and it's just 8

fine, you're differing with that.

9 And I'm kind of getting back to what 10 Dennis kind of tried to say yesterday about, there's 11 either going to be a letter that's not real positive 12 about the SE or there's going to be some differing 13 opinions. And I'm kind of trying to say, nope, there 14 may be differing opinions on what's needed but all of 15 us so far have said, no, the SE needs to have 16 something else done, don't issue it without some 17 changes.

18 MEMBER KIRCHNER: No, I said that. And I 19 think that's --

20 MEMBER PETTI: No, I --

21 MEMBER KIRCHNER: -- a premature --

22 MEMBER PETTI: Yes.

23 MEMBER KIRCHNER: -- conversation. Joy, 24 the ACRS can issue a letter with or without the SE.

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72 MEMBER REMPE: Well --

1 MEMBER KIRCHNER: So I don't think we have 2

to tie the conversation to yes or no on the SE. Let's 3

address, first, whether we can come to a consensus as 4

Dennis had outlined, and others, and then talk about 5

yes or no, issue the SE.

6 Because we can always, and we have in the 7

past --

8 MEMBER REMPE: You're right, I overstated 9

what I'm saying. We're not happy with what we've 10 seen, but again, the Staff wrote up some things, well, 11 there was a White Paper, but this topic, as far as the 12 focus area goes, nobody is happy with what we've seen 13 from the Staff.

14 MEMBER KIRCHNER: No.

15 MEMBER REMPE: Changes throughout.

16 MEMBER KIRCHNER: No.

17 MEMBER PETTI: No, no, I don't think 18 that's --

19 MEMBER KIRCHNER: That's not correct at 20 all.

21 MEMBER REMPE: Ah. Okay. So then we're 22 not there yet, I thought maybe we were.

23 MEMBER KIRCHNER: No, we're not there yet.

24 We've had very good input from the Staff. And I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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73 that input, I will reinforce my opening comments.

1 If you look at Dave's picture, both the 2

design changes, the setpoint changes and such that 3

were proposed by the Applicant, appear to address that 4

whole set of sequences very successfully. And that's 5

all to the good.

6 And then we've heard from the Staff from 7

the, also on the right-hand side. And so, yes.

8 MEMBER REMPE: But I thought even Dave was 9

saying that with the recovery actions that haven't yet 10 been defined, I mean, Walt you had said, maybe a text 11 needed to be added. And I think, what I was kind of 12 interpreting what Dave was saying

was, the 13 confirmatory action might need to have more because 14 right now they just, they need to identity something.

15 But if they had to be --

16 MEMBER KIRCHNER: Well -

17 MEMBER REMPE: -- maybe a more in-depth 18 decision --

19 MEMBER KIRCHNER: -- again, as Dennis 20 pointed out, we're not in the business of doing design 21 fixes or changes. But I think --

22 MEMBER REMPE: I think that changes the 23 Staff --

24 (Simultaneous speaking.)

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74 MEMBER KIRCHNER: One doesn't, one just 1

doesn't leave the system in post-ECCS actuating, 2

continuing to deborate. But let me stop there.

3 CHAIR SUNSERI: This is Matt. And my view 4

on it is I agree. I think it's still a little early 5

to be talking about carve outs and how we're going to 6

address this thing because, at least in my mind what 7

the situation is, is the Staff has completed their 8

safety evaluation report.

9 And through all of their deliberations and 10 engineering analysis and interactions with the 11 Applicant, they have come to the conclusion that they 12 are reasonably assured that the systems that exist, as 13 identified in the design certification documentation, 14 there's a reasonable assurance that those systems can 15 be operated to overcome the situation created by the 16 event as described.

17 MEMBER MARCH-LEUBA: I don't think they're 18 saying that in the SER. And when --

19 (Simultaneous speaking.)

20 MEMBER MARCH-LEUBA: -- surface --

21 CHAIR SUNSERI: -- SER if they didn't 22 haven't reasonable assurance that --

23 MEMBER MARCH-LEUBA: When you scratch 24 under the surface you find out they have no basis for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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75 the conclusion.

1 CHAIR SUNSERI: I just said they used 2

reasonable, engineering analysis. And they've told us 3

what that evaluation is.

4 MEMBER MARCH-LEUBA: Well --

5 CHAIR SUNSERI:

We heard from it 6

yesterday.

7 MEMBER MARCH-LEUBA: And that's why we're 8

here, to review the reasonable analysis. I don't see 9

any evidence that that is the case.

10 MEMBER KIRCHNER: Matt?

11 CHAIR SUNSERI: Yes.

12 MEMBER KIRCHNER: This is Walt. I forgot 13 that I also wanted to give our, I hope, did everyone 14 on the Committee have a chance to talk, and if so, I 15 would like to turn to our consultants. May I do that?

16 MR. CORRADINI: Are you asking or telling?

17 MEMBER KIRCHNER: Hearing no objection --

18 that sounds like Mike Corradini for the record. Mike, 19 go ahead.

20 MR. CORRADINI: Okay. So, a lot of things 21 have been said, and I don't think it's appropriate or 22 time effective to repeat them.

23 Let me start off with Dave's figure 24 because I think Dave's figure at least outlines quite 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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76 well pathways. The one pathway that we are discussing 1

about after actuation DBA rule set conservative 2

calculations, is there is not a calculation that looks 3

at what apparently is going to be a delusion of the 4

downcomer, as time marches on, past actuation.

5 There is an analysis, 89.30. But that 6

wasn't the purpose of the analysis. And if anything, 7

it just looks to make sure that you have enough boron 8

concentration in the core to remain sub-critical.

9 Rather, it's not even conserving boron, it 10 loses boron from the system. It magically disappears.

11 Which tells me that it's probably in the downcomer but 12 I don't know how much is there.

13 So Step 1 would be, I would think, it's 14 appropriate that if we're going to talk about recovery 15 actions we have to have either a conservative or at 16 least an appropriate calculation that gives us an 17 opinion as to how rapidly we are diluting the 18 downcomer region.

19 Now, what we've been told by 89.30, and 20 I've got to be careful that we don't say words that, 21 or numbers that are inappropriate in open session, is 22 it's probably less than a day. It seems to me then I 23 would turn to an approach that Member Kirchner, that 24 Walt has discussed, which is, I don't know if the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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77 proper legality is carve out or whatever, but it seems 1

to me working the problem backwards, that if you want 2

to have a short recovery actions you either have to 3

identify now that such recovery actions have to occur 4

before you have a chance of any sort of power increase 5

or re-criticality or you come up with a strategy now 6

that says how you approach criticality and then 7

monitor your recovery actions.

8 As I think Jose indicated, there are four 9

recovery actions. Three of which require the CVCS in 10 operation. And the best of the three is essentially 11 injection into the riser region.

12 If the CVCS is not available, then you 13 have the CFDS to do it. And then you either have to 14 do, as Mark and Matt suggest, are approach to 15 criticality, which is quite reasonable and logical.

16 And actually takes, I think, a much easier approach 17 than some other required emergency actions that we 18 have reviewed in current operating reactors that have 19 to occur in tens of seconds, not in hours. Or tens of 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />. And you can do it that way.

21 But whatever the recovery action is has 22 got to be identified within the, at least a structure 23 for the recovery action that have got to be identified 24 within the DCA.

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78 And that leads me to the final thing which 1

is, when we were discussing with Staff yesterday, I 2

think I asked someone on Staff, is it their feeling 3

that this is inappropriate at this time but it can be 4

done in the COL stage. This is, I guess, where I 5

differ with the Staff's conclusion.

6 Is that I think something has got to be 7

defined here, either by a limitation or an additional 8

requirement, I'll call it requirement, that you 9

essentially have some sort of overall strategy that 10 then has to be backed up by a calculation. And then 11 I think we're good to go relative to the SER.

12 I can explain further but I thought I'd 13 try to be brief.

14 MEMBER MARCH-LEUBA: Mike, I like what you 15 said very much.

16 MEMBER KIRCHNER: Thank you, Mike.

17 MEMBER MARCH-LEUBA: And I think you make 18 sense. This is what we would be calling, define a 19 success path.

20 Tell me how you're planning to do it and 21 show me that you can do that. That's fine.

22 MR. CORRADINI: I think, again, it's the 23 Members' decision here. But it seems to me that we're 24 not differing with, and in fact, I don't want to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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79 redesign the system, that's the Applicant's problem, 1

not our problem.

2 So to the extent that they're happy with 3

their design as they stated, then they have to show a 4

path to recovery that can be successful given the 5

potential chance that some of these systems would be 6

inoperable given whatever the initiating event would 7

be.

8 And so, that might be the limitation that 9

I would put on the current SER as written. And the 10 design as presented.

11 MEMBER MARCH-LEUBA:

It is my 12 understanding that these types of SERs cannot have 13 limitation. They either approve or disapprove this 14 litigation, but you cannot have limitations and 15 conditions it will have to be a modification of the 16 FSAR.

17 MR. CORRADINI: Okay, I'm not going to 18 deal with whatever the right word is, but I think I've 19 made my point.

20 MEMBER BLEY: Mike --

21 MEMBER KIRCHNER: Thank you, Mike.

22 MEMBER BLEY: -- a thought I had forgotten 23 about. And that is, at least a few of us have talked 24 about this.

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80 I think that the Staff's point of view, 1

and I'd like to say something about this in our 2

letter, the Staff's absolute conviction that because 3

of their guidance they don't have to consider recovery 4

as part of Chapter 15 as inappropriate.

5 I think that's normally reasonable when 6

the paths of recovery are clear. Then once you've 7

stabilized at the end of Chapter 15 there is no big 8

issue about how you go forward.

9 In a case where there is a big issue and 10 it hasn't been proved, or designed out, that you 11 really need to do something, and it's not six months 12 later, I don't think the safety analysis is complete.

13 And I think we ought to make a point of that.

14 MEMBER KIRCHNER: Thank you, Dennis. Well 15 said. Let me turn and just check, because I'm not 16 monitoring the sidebars. Steve Schultz, are you on 17 the line?

18 MR. SCHULTZ: I'm here.

19 MEMBER KIRCHNER: Steve, do you wish to 20 add anything? I lost him. I think we might have lost 21 him.

22 CHAIR SUNSERI: Steve, are you on mute?

23 Let's take a moment --

24 MR. SCHULTZ: Can you hear me now?

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81 CHAIR SUNSERI: Yes. Go ahead, Steve.

1 MR. SCHULTZ: All right. I just wanted to 2

follow-up with what Mike's last comment associated 3

with moving forward and Dennis' wrap-up associated 4

with what needs to be done with regard to procedures.

5 I do think the combination of the 6

approaches that Matt mentioned, and you, Walter, 7

mentioned, associated with ways in which the purple 8

box can be addressed ought to be filled out by the 9

committee in the letter in some fashion. Not 10 suggesting that be done but rather that there be 11 closure associated with identifying what needs to be 12 done there.

13 The impression I had from the most recent 14 meetings is that the, both the Applicant and the 15 Staff, in fact as Dennis said, are relying upon the 16 fact that they're not required to do the recovery 17 action portion until later.

18 In fact, they seem to rely too heavily on 19 what's going to happen with the Applicant later on.

20 Which is certainly, I think, bothersome.

21 Also, my impression is that the Staff and 22 the Applicant, in the audits that have been, I'll call 23 it one audit, but it's been months of activity that's 24 gone on here to address the issues that came up 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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82 earlier this year.

1 And it was mentioned yesterday, at least 2

then, and before from the presentations we've had, 3

they've been having daily discussions associated with 4

these. And I can't believe in the Staff's forming 5

their engineering judgements and their overall 6

analyses and the Applicant's review of what they 7

presented.

8 There's been a lot of back and forth 9

associated with what approaches would be taken, should 10 be taken with regard to this. And yet it's not 11 documented.

12 I agree with the, I wish it was going to 13 be documented in the audit report but I don't think it 14 is going to be to the level that we would like to see.

15 So I think there is more work that needs to be done 16 there.

17 On the technical side, I think that we 18 ought to be able to, as Walter said, there are 19 methodologies that could be used. If not to draw a 20 definitive conclusion, to help move things along in 21 the right direction with understanding the issues, 22 technical issues, better on the core recovery side.

23 And I also think that there must be some 24 simple evaluations that can be done with regard to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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83 boron tracking that could help address some of the 1

best estimate beliefs of where the boron in fact is in 2

the system. It's not clear what's been done 3

specifically, even given the modifications that have 4

taken place to help with the boron mixing in the 5

downcomer during operation.

6 MEMBER BLEY: That's great. This is 7

Dennis again. And Steve just jogged another jog on my 8

memory. And it goes along with my last comment a bit 9

about safety analysis not quite being done.

10 Part 52, although it's been around for 40 11 years now, we have, we, the ACRS, the Staff and the 12 Commission have very limited experience with Part 52.

13 We've got a handful of design certs that have been 14 spread over the years, we've got less than a handful 15 of continuations toward the operating, combined 16 license.

17 And we're still early in making this thing 18 work well. I think that needs to be on everybody's 19 minds.

20 MR. MOORE: Member Kirchner?

21 MEMBER REMPE: Next could I add on? Or 22 Walt, could I add on something into that comment.

23 MEMBER KIRCHNER: Yes, and then I detest 24 Scott Moore, the Executive Director, wants to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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84 interject something too. Go ahead, Joy, if it's 1

short.

2 MEMBER REMPE: So, your comment would 3

bring up a comment that Harold Ray said about it's 4

very, Part 52 was meant for a reactor that's been 5

built. And we so far, and my understanding is that we 6

don't know evolutionary designs.

7 Isn't this one, this is a bit more than a 8

traditional evolution, it's a new design. And if 9

others with dramatically different designs, it may be 10 stretching its applicability even more. Right?

11 MEMBER KIRCHNER: Is that a statement or 12 a question?

13 MEMBER REMPE: Well, it's a question that 14 I think is a statement, but it's just another thought.

15 MEMBER KIRCHNER: It's something, Joy, 16 would you hold that because that certainly would fit 17 into our observation's lessons learned letter. And 18 maybe, so we don't divert from today's focus area, if 19 you save that, think about it and we can add that to 20 our observation's lessons learned.

21 MEMBER REMPE: You bet.

22 CHAIR SUNSERI: Hey, Walt, this is Matt.

23 It's almost 1:30, I think we need to take a lunch 24 break here pretty soon so if you can find an 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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85 appropriate cutoff point --

1 MEMBER KIRCHNER: I think this is the 2

appropriate time, but I thought I detected Scott 3

wanting to make a comment.

4 CHAIR SUNSERI: Okay. All right.

5 MR. MOORE: Yes, Chairman Kirchner. Steve 6

Schultz mentioned the audit and the audit report. And 7

as the Chairman mentioned, we've asked for the audit 8

report.

9 We also have some information about the 10 audit report. Including, we've heard some about what 11 will and won't be in it.

12 And the Committee may, since they've asked 13 the Staff to be here, may want to ask the Staff what 14 will and won't be included in the audit report. But 15 I'd ask that Mike Snodderly be recognized about when 16 we will receive the audit report.

17 CHAIR SUNSERI: Yes.

18 MR. MOORE: Mike.

19 CHAIR SUNSERI: Go ahead, Mike.

20 MR. SNODDERLY: Yes, so the Staff notified 21 me this morning that they're planning on providing the 22 audit report to the Committee on July 17th. So that's 23 seven days from now. Next Friday.

24 As I've been closely watching the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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86 interactions between the Staff and NuScale during the 1

audit I have the audit plan. And I think it's 2

important to recognize that one of the most important 3

purposes, or what I saw that came out of the audits, 4

was assuring that there was sufficient material in the 5

FSAR, which is as we all know is the licensing basis 6

for the plant not the FSAR.

7 And that resulted in three important 8

submittals. The May 20th submittal, the May 28th 9

submittal, which was the supplemental response to RAI 10 89.30, and then a June 19th submittal.

11 And it was that additional material that 12 NuScale intended to address the boron distribution 13 issue. Redistribution issue.

14 So I think the Committee should be focused 15 that that is the material and the analysis that 16 supports the Staff's FSAR.

17 I expect the audit report, this is, again, 18 this is just my opinion of the expectations, that I 19 believe that the report will just mainly, the audit 20 report will just document that they did do what the 21 plant said and here's the documents they looked at.

22 And then it probably, we've referenced the resulting 23 submittals.

24 But I do not expect for that audit report 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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87 to have discussions of analyses and an audit where 1

(audio interference) --

2 CHAIR SUNSERI: Mike, I think we're losing 3

your audio.

4 MR. SNODDERLY: I'm sorry, but I wanted to 5

just share my observations on the (audio interference) 6 7

MR. MOORE: So I can pick up from Mike.

8 I think Mike was saying, we didn't expect a lot more 9

detail in the audit report based on what we were 10 hearing then what Mike just mentioned.

11 But since the Staff is here in this 12 discussion the Committee can always ask the Staff 13 about what's in the audit report. Which is not yet 14 final.

15 That's all we really had to say. When it 16 was coming in and what we're hearing about will be in 17 the audit report. Thank you.

18 MEMBER PETTI: So, Scott, just a question.

19 I mean, that was my sense even though we didn't fully 20 understand Mike.

21 It just seems to me that there was a lot 22 of discussion in the last day about this 89.30 23 supplement and many members couldn't find it. They 24 could find earlier responses that were titled 89.30.

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88 But if we could have Mike make sure the 1

supplement gets put in the right folder and share 2

point --

3 MR. SNODDERLY: Can you hear me now? Can 4

you hear me?

5 MR. MOORE: Yes.

6 MEMBER KIRCHNER: Yes, we can, Mike.

7 MR. SNODDERLY: Okay, thank you. Yes, so 8

if, it is, I will send the link to your email, but it 9

is there under the June 3rd meeting under NuScale 10 documents. So it's not under the May 20th submittal 11 because it came in afterwards but if you look under 12 the documents folder all three 89.30 responses are in 13 there, and the supplemental response from May 28th.

14 But I'll send out a link for you all to, 15 well, so you can find it. But it's all there.

16 MEMBER MARCH-LEUBA: Hey, Walt, are we 17 going to come back to this discussion after the lunch 18 break or are you going to cut me off?

19 MEMBER KIRCHNER: Well, I was going to 20 test the Members quickly to see, obviously we're not 21 going to turn a letter around for you, the Committee 22 to review by the end of the lunch break, that's not 23 realistic or desirable I don't think.

24 So --

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89 (Simultaneous speaking.)

1 MEMBER MARCH-LEUBA: Yes, but --

2 MEMBER KIRCHNER: Do you want to continue 3

4 MEMBER MARCH-LEUBA: -- the schedule --

5 MEMBER KIRCHNER: Jose, do you wish to 6

continue deliberations --

7 MEMBER MARCH-LEUBA: There is very short 8

9 MEMBER KIRCHNER: -- in the public forum?

10 MEMBER MARCH-LEUBA: There is a very short 11 point I wanted to make. It is my impression that Dr.

12 Yarsky's conclusions are being misquoted.

13 Because Pete and I are very good friends 14 and we talk with each other. And often we know what 15 the other one is going to say and where they're not 16 saying it.

17 So I would like to explain to you what 18 actually Peter Yarsky said about the $20 insertion 19 into the core. And maybe we have him, he can explain 20 to us what he meant. Because he's being misquoted.

21 MEMBER KIRCHNER: Okay. If we can do it 22 quickly then, because I think, wait a minute, let me 23 do a check with the Chairman.

24 CHAIR SUNSERI: Yes --

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90 MEMBER KIRCHNER: Matt?

1 CHAIR SUNSERI: -- let's hold that for 2

after lunch because --

3 MEMBER KIRCHNER: Okay.

4 CHAIR SUNSERI: -- it can only lead to 5

more discussion I think.

6 MEMBER KIRCHNER: Right.

7 CHAIR SUNSERI: And we've been at this a 8

long time. It's already 1:30 there on the east coast, 9

we need to give people a rest so they can have lunch.

10 And that would be my recommendation.

11 MEMBER KIRCHNER: Okay. Let's take the 12 break. And I just ask my colleagues, I've been taking 13 notes. I had a lot of good input.

14 If you have suggestions on, and directions 15 or input for this letter that we will pull together, 16 maybe we can collect that and then come up with a 17 tentative schedule, Matt, for us, a subset of us to go 18 off and pull together a letter for us.

19 CHAIR SUNSERI: Right. I think by the end 20 of the day, I think by the end of the day it would be 21 almost critical that we end up with a list of pretty 22 specific topics that are going to be included in the, 23 that we have consensus on to be addressed in the 24 report.

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91 MEMBER KIRCHNER: Right.

1 CHAIR SUNSERI: An outline essentially.

2 And then we can go fill in the details, the writers 3

can go fill in the details offline.

4 MEMBER KIRCHNER: Okay. Thank you.

5 MR. MOORE: And just to ask, we do want 6

the court reporter back after lunch, correct?

7 CHAIR SUNSERI: I think so, Scott. Yes.

8 MR. MOORE: Okay, thank you.

9 MEMBER REMPE: Could I ask about tomorrow?

10 What's, are we going to still try and do something 11 tomorrow too or do we know that yet?

12 CHAIR SUNSERI: If we can get to our 13 consensus on this outline by the end of the day that 14 will be the end of this week's meeting, so no session 15 tomorrow.

16 MEMBER REMPE: Thank you.

17 MEMBER KIRCHNER: Yes, I concur, Matt. I 18 really think we need the time to do, offline, to do 19 this.

20 MEMBER BLEY: Quick question for Matt or 21 Scott, or somebody. Do we have any idea how expedited 22 this transcript will be because I think this is 23 important for us to have in hand as we finish this 24 stuff up?

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92 CHAIR SUNSERI: I understand it would be 1

three days.

2 MR. MOORE: At least --

3 MEMBER BLEY: That would be fabulous. And 4

if Mike would get it to all of us right away I think 5

that would be helpful.

6 CHAIR SUNSERI: Alicia, can you confirm 7

that? I was told three days.

8 MR. MOORE: Yes, that's my understanding 9

too.

10 CHAIR SUNSERI: Yes, okay.

11 MR. SNODDERLY: I'm sorry, was I just 12 committed to something? I was, I lost myself.

13 MR. MOORE: No, just distributing the 14 transcript as soon as we get it.

15 MR. SNODDERLY: Oh. Oh, of course. Of 16 course. Yes, understood. And yes, my understanding 17 is that an expedited transcript is three days.

18 CHAIR SUNSERI: Okay, anything else before 19 we recess for lunch? All right --

20 MEMBER BALLINGER: Are we back in open 21 session?

22 CHAIR SUNSERI: We'll come back in open 23 session at 2:30 eastern. Okay. So we are recessed 24 until 2:30 eastern. Thank you all.

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93 (Whereupon, the above-entitled matter went 1

off the record at 1:39 p.m. and resumed at 2:30 p.m.)

2 CHAIR SUNSERI: Okay. This is Matt 3

Sunseri. It is 2:30, and let's start with a roll 4

call. Ron Ballinger?

5 MEMBER BALLINGER: Here.

6 CHAIR SUNSERI: Dennis Bley? Was that 7

Dennis?

8 (No audible response.)

9 CHAIR SUNSERI: Vesna Dimitrijevic?

10 MEMBER DIMITRIJEVIC: Here.

11 CHAIR SUNSERI: Walt Kirchner?

12 MEMBER KIRCHNER: Here.

13 CHAIR SUNSERI: Jose March-Leuba?

14 MEMBER MARCH-LEUBA: I am here.

15 CHAIR SUNSERI: Dave Petti?

16 MEMBER PETTI: Here.

17 CHAIR SUNSERI: Joy Rempe?

18 VICE CHAIR REMPE: Here.

19 CHAIR SUNSERI: Pete Riccardella?

20 MEMBER RICCARDELLA: Here.

21 CHAIR SUNSERI: Dennis Bley?

22 (No audible response.)

23 CHAIR SUNSERI: Last call for Dennis.

24 (No audible response.)

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94 CHAIR SUNSERI: Okay. We do have a 1

quorum, and we will reconvene. Remember we're on the 2

transcript. And I'm going to -- before we begin --

3 restart the deliberation on the report preparation, I 4

want to just say I was remiss for not giving NRC staff 5

a chance to make a comment earlier today. So I'm 6

going to call on Anna Bradford at this point for her 7

comment or statement.

8 MS. BRADFORD: Yes, thank you. Can you 9

confirm you can hear me?

10 CHAIR SUNSERI: Yes, Anna. We can hear 11 you.

12 MS. BRADFORD: Thank you very much. So I 13 appreciate the conversation earlier today and allowing 14 the staff to listen in. There's a lot really good 15 points. I just wanted to bring up a couple, I will 16 say, process thoughts that I had while you were 17 deliberating.

18 And one was someone had raised the idea of 19 a carve out for this issue. And I just wanted to let 20 you know this is really not a candidate for a carve 21 out. A carve out is a very, I'll say, specific 22 regulatory tool that can be used in certain 23 circumstances, and this is not one of those 24 circumstances.

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95 I say that because the regulations do not 1

require that the applicant give us or show us any kind 2

of procedures for recovery at the design cert stage.

3 So a carve out is when we say we cannot give them 4

regulatory finality on some regulation that is 5

required for a design certification. That's not the 6

case here. So I just don't want you guys to start 7

thinking, okay, we'll say this should be a carve out, 8

because that's really not an open path for the staff 9

to use that regulatory tool.

10 In addition, the discussion about revising 11 the SE, I would have to think about how we would 12 revise the SE because, again, the SE as it is right 13 now shows that we believe we have reasonable assurance 14 against the regulations. And that argument is laid 15 out there in the SE. So again, I'm not sure how we 16 would revise the SE in accordance with what you guys 17 were talking about earlier today. I'm not saying it 18 can't be done. I'm just struggling with what that 19 would be since, like I said, we were already making 20 our regulatory findings against the regulations.

21 And my last thought is there seems to be 22 some discomfort, I'll say, with the idea of leaving 23 some things to the COL stage. And I mean, as you all 24 know, the fact is that is allowed. There's a lot of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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96 important things that are left to the COL stage that 1

are not necessarily resolved at the DC stage.

2 Reasonable people can disagree on where 3

that line should be, what should be in the DC, what 4

should be in the COL. We talk about it all the time.

5 Industry asks about it all the time. But with this 6

particular issue, it's pretty clear that it's not 7

required at the DC stage. I will just mention there's 8

a lot of -- someone mentioned that maybe the Part 52 9

isn't quite meant -- or maybe doesn't fit exactly for 10 evolutionary designs.

11 And I will say that there are some light 12 water SMR designers that are thinking about coming in, 13 in the next few years under Part 50 and asking for, 14 first, a construction permit and then an operating 15 license. And the level of detail and design that we 16 get at the construction permit stage is going to be 17 much less than we're seeing now at the DC stage. This 18 is going to be an ongoing conversation in terms of, 19 what do we need to make reasonable assurance finding 20 at these various stages of licensing?

21 So that's all I really wanted to say. It 22 was just to point out that this is -- our approach is 23 allowed under the regulations. We think we found 24 reasonable assurance. The Committee can certainly 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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97 disagree with that. If you have suggestions on what 1

the staff needs to do within the bounds that it has to 2

address that in your letter, I mean, that would be 3

much appreciated by us. That's all I wanted to say.

4 Thank you for the opportunity.

5 CHAIR SUNSERI: Thank you.

6 MEMBER MARCH-LEUBA: Can I ask a question 7

from Anna?

8 CHAIR SUNSERI: It's really -- I mean, if 9

it's a question of clarification, I will grant it.

10 But we're not going to debate.

11 MEMBER MARCH-LEUBA: It's a clarification.

12 It's not a debate.

13 CHAIR SUNSERI: Okay.

14 MEMBER MARCH-LEUBA: Okay. Anna, if, 15 during your review, you had reason to believe that the 16 risk in terms of core damage frequency reported in the 17 FSAR was incorrect and the applicant had not provided 18 any calculation or justification for a number of 19 accidents that are postulated certainly by me and by 20 one of your members, would that rise to the level of 21 high carveout? Because you don't have any reason to 22 believe that the deboration events don't read to 23 significant risk to the core.

24 MS. BRADFORD: So I think this is another 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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98 thing that might fall into a gray area that could be 1

discussed. There are some things that are so 2

fundamental to the design that you can't really even 3

carve it out and still approve this, right? I mean, 4

so if we didn't have the, like you were saying, maybe 5

important information about the core or we didn't have 6

the design of the containment or something like that, 7

that's hard to carve out and still approve the design 8

as a whole. So whether --

9 MEMBER MARCH-LEUBA: But this --

10 MS. BRADFORD: -- what you were mentioning 11 falls into that, I don't know. I don't know that we 12 necessarily had those discussions, and it's hard to 13 talk about what if type scenarios like that.

14 MEMBER MARCH-LEUBA: My concern, and I 15 don't want to get into an argument, is it's not the 16 procedures. It's that there will be operator errors 17 of commission which will start CFDS after the 18 downcomer will deborate. And you decide what the 19 probability of those things are. Those things are not 20 in the risk analysis. You're missing a big chunk.

21 And one member of your staff believes it's seven 22 orders of magnitude larger than what they published on 23 the FSAR.

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99 point, Jose. We're not going to -- I think we should 1

save those kind of questions for Committee 2

deliberation, not going back to the staff.

3 MEMBER RICCARDELLA: Matt, could I ask a 4

question?

5 CHAIR SUNSERI: Yes.

6 MEMBER RICCARDELLA: This is Pete. So 7

Anna, short of a carve out, is there some other way 8

that we can flag this to make sure that it's 9

considered a very important item that needs to be 10 addressed and make sure it doesn't --

11 (Simultaneous speaking.)

12 CHAIR SUNSERI: I understand what you're 13 saying. Yeah, I understand what you're saying, Pete.

14 And maybe some other members may correct me on this, 15 but let me just very high level philosophically 16 discuss what I'm about to say. So clearly, the staff 17 is bound by the regulations and that's their charter 18 to go look at the regulations in depth as they are 19 written and apply that to the application that is 20 before and make the reasonable assurance 21 determination.

22 I'm going to make a broad leap here and 23 just say Congress in its wisdom recognized that maybe 24 all regulations couldn't be written so prescriptively 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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100 that they would always ensure safety. So they created 1

an independent Advisory Committee on Reactor 2

Safeguards for us to look at the results of the safety 3

evaluation that's being produced by the staff and come 4

to our independent conclusions. We don't write the 5

SER. We don't tell the staff how to do their 6

business.

7 We review their work and we fill in the 8

gaps where we see potential safety issues. We write 9

those up in our letters, and that's how we do it. So 10 it, your point is, yes, we can point out where we 11 think there are safety significant issues that need to 12 be addressed before a final license is granted, or 13 maybe even a DCA. But we'll have to figure out what 14 that message is and then we'll it in our letter.

15 MEMBER RICCARDELLA: So you're saying our 16 letter in itself is a way to flag it?

17 CHAIR SUNSERI: Our letter goes -- it is 18 part of the rule.

19 MEMBER KIRCHNER: It's a crucial part of 20 our function, Pete. And I have had in the last few 21 days input and contact from people I haven't heard 22 from for years. So these proceedings are actually 23 being paid attention to. An ACRS letter does have 24 impact.

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101 CHAIR SUNSERI: I hope that addressed your 1

question, Pete.

2 MEMBER RICCARDELLA: It does.

3 CHAIR SUNSERI: Okay. Thank you. Any 4

other members have anything they want to add at this 5

point?

6 (No audible response.)

7 CHAIR SUNSERI: All right. Thank you, 8

all. And I will now turn the floor over to Walt for 9

a continuation of the report preparation.

10 MEMBER KIRCHNER: So colleagues, what I 11 would like to do is capture your major comments. I 12 was not able to do justice to taking notes and also 13 participate in the meeting. So Sandra is standing by.

14 We had some very good input.

15 What I would like to do in this open forum 16 is just capture any major items that you feel the 17 letter should address, and we can do this in 18 shorthand, perhaps cryptic form. And we will collect 19 those, and then a smaller group will take this 20 information and ensure that we reflect in a draft 21 letter on the topic of boron dilution. So with that, 22 I hesitate to put people on the spot. Dennis, are you 23 there?

24 (No audible response.)

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102 MEMBER KIRCHNER: I know we missed him 1

because he had several salient comments. Well, let me 2

just go them through the roster. Ron Ballinger, what, 3

if any, major comments or input do you want to see 4

reflected in this letter?

5 MEMBER BALLINGER: I think the -- I think 6

other people are going to say the same thing. But I 7

would like to be sure that in the letter, we stress 8

that there needs to be a well identified recovery 9

path. I'm not sure what well means, but you get my 10 point, I think.

11 MEMBER KIRCHNER: Okay. Let's see.

12 MEMBER BALLINGER: That's it.

13 MEMBER KIRCHNER: Go ahead. I'm just --

14 I'm doing this from memory, so bear with me while I go 15 through the roster. Dennis, are you on the line?

16 (No audible response.)

17 MEMBER KIRCHNER: Does anyone want to take 18 a stab at Dennis' earlier comments? What I remember 19 20 VICE CHAIR REMPE: Walt, can I help you?

21 MEMBER KIRCHNER: -- that the FSAR and the 22 SER were really not clear in identifying this 23 particular issue.

24 CHAIR SUNSERI: Hey, Walt, I think --

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103 VICE CHAIR REMPE: Walt --

1 CHAIR SUNSERI: -- Joy has some --

2 MEMBER KIRCHNER: Go ahead, Joy.

3 VICE CHAIR REMPE: I actually took the 4

notes on that session and put them on Jose's thing 5

because I wanted to make sure we got it. But it was 6

the guidance about --

7 MEMBER KIRCHNER: Okay.

8 VICE CHAIR REMPE: -- not having to 9

identify recovery. The staff is just following the 10 regulations, and it's not required that they have to 11 identify that, right?

12 MEMBER MARCH-LEUBA: Yeah, the part I --

13 VICE CHAIR REMPE: Is that what you think 14 he said?

15 MEMBER MARCH-LEUBA: The part I liked 16 about Dennis' talk earlier -- and I wish he was here.

17 Maybe we should wait for him. He said that for normal 18 reactors, you end up in a safe and stable condition 19 and there's a clear path to get out of it. Here, we 20 don't. And it is a tricky path, especially for some 21 failures, and that's what he said, that --

22 (Simultaneous speaking.)

23 MEMBER KIRCHNER: Yeah, I think he was 24 getting at suggesting -- go ahead, Jose. Sorry.

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104 MEMBER MARCH-LEUBA: Yeah, this is not the 1

same situation.

2 (Simultaneous speaking.)

3 MEMBER KIRCHNER: He's suggesting the 4

completeness of the Chapter 15 analysis. If you come 5

out of a Chapter 15 analysis to most reactor in the 6

existing fleet and such, when you do those Chapter 15 7

analyses, and all of us have been involved in them in 8

one way or other, usually -- let me make up something 9

on the spot. You reflood the core. You're done, 10 right? And the event is terminated. You've reached 11 the safe, stable condition.

12 Here what I note was, for example, and the 13 applicant did a good job. They were able to point out 14 that the core was very well borated. So that was one 15 of their, if you will, not only was the core covered, 16 the SAFDLs were not violated. And there was actually 17 a higher concentration of boron than at shut down or 18 when the transient was initiated.

19 But it begs the question, is that set of 20 metrics completed? Because, again, I come back to the 21 staff's presentation yesterday where for the DHRS 22 system performance, they demonstrated that there was 23 significant margin above critical boron concentration 24 in the downcomer at 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after those DHRS event 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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105 paths, both at beginning of core and BOC and -- sorry, 1

beginning of cycle, I misspoke, and middle of cycle 2

with good margin. It just begged the question of me 3

that why don't we see that for the post-ECCS of boron 4

dilution because it would suggest that you could 5

analyze the trajectory of the event after ECCS 6

injection and look at the boron dilution of time.

7 And at some point -- and it will vary with 8

the event analyzed. But basically, you'll see that 9

the boron concentration is diluted. And at some 10 point, you're at some level above critical boron 11 concentration for the core inlet. And it suggests at 12 least to me that's a trigger point. You better 13 intervene.

14 But we didn't see that. We only saw it 15 for the successful path that addressed the design 16 changes that were made that included the set points 17 and the holes in the riser, et cetera. So I think 18 Dennis was hinting at the fact that --

19 CHAIR SUNSERI: Hey, Walt. Dennis is on 20 the line now, I believe.

21 MEMBER KIRCHNER: All right. Now I'll 22 stop talking. Dennis, I was trying to reconstruct 23 your input from this morning about the FSAR and FSER 24 not having the visibility on this matter. And I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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106 you were hinting at the suggestion that the Chapter 15 1

stylized analyses, for this reactor being somewhat 2

different, were, I'll put words in your mouth, 3

somewhat incomplete.

4 MEMBER BLEY: Yeah, I thought I did more 5

than hint. The history of our regulations and how we 6

address these things really evolve over many years.

7 And I think the staff is over-reading their guidance.

8 I think whatever -- and I haven't looked up the 9

guidance on this point. I think whatever guidance 10 they have that says, you stop once everything is 11 initially stable, is historically based on the fact 12 that at that point, hands off and almost any hands on, 13 you're going to take it back to a normal condition.

14 This is an unstable point, at least as far 15 as we know because nobody has done the analysis to 16 prove it's not. And therefore, I don't see that it's 17

-- because it's recovery, it belongs in the next phase 18 of licensing. By the way, Part 52, it's this the 19 sixth or seventh exercise of it. If you're on Part 20 50, you wouldn't be putting things off. You'd be 21 selling them on the spot. And I think this one that 22 most of the designers of this process have said, no, 23 we aren't there yet. Let's finish this analysis.

24 CHAIR SUNSERI: So Dennis, what Walt has 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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107 been doing is we have a white sheet of paper up on the 1

screen there, and Sandra is recording the key points.

2 So do you want to summarize for Walt and Sandra what 3

that message is so she can capture it on this piece of 4

paper?

5 MEMBER BLEY: Okay. Let me try. And this 6

is something I think Walt, Vesna, and I and Jose 7

talked about some weeks ago is that we think -- I 8

think completion -- let's go, Sandra -- completion of 9

the analysis in Chapter 15 --

10 MS. WALKER: I'm sorry. For some reason, 11 the audio kept breaking up.

12 MEMBER BLEY: Oh, sorry. Completion --

13 can you hear me? I'll call in on the phone if this 14 isn't working. It's worked up till now.

15 CHAIR SUNSERI: I can hear you, Dennis.

16 MEMBER KIRCHNER: Yeah, you sound good.

17 MEMBER BLEY: Completion of the Chapter 15 18 analysis for events involving long-term deboration of 19 the downcomer should have a path to -- instead of to, 20 through recovery explained in the DCA, something like 21 that. Anybody is free to fiddle with it.

22 MEMBER KIRCHNER: Good. Thank you, 23 Dennis.

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108 fiddle with it, I don't know if everyone agrees with 1

this point. But it seems clear to me that you don't 2

leave yourself tottering on the tip of a cone.

3 CHAIR SUNSERI: Just for clarity, what 4

Walt's trying -- and you were on the first part.

5 Walt's just trying to capture everybody's main points, 6

and then we'll go through and get consensus on these 7

things. And they don't have to be perfect because 8

we've got the transcript but just enough information 9

there so we know what it is and not forgetting about 10 it. That's kind of the theme of this exercise we're 11 going through.

12 VICE CHAIR REMPE: So could I note that 13 when you try to introduce this point, Dennis, a few 14 minutes ago, you also mentioned that the guidance or 15 the regulation may not be appropriate at this point 16 for this more evolutionary design or something.

17 You're going to have to say it better than me. But I 18 think that that's an important point you raised that 19 I think ought to be covered in the letter because 20 Anna, and maybe you missed it, had said it's what the 21 regulations say. Anna Bradford made a comment at the 22 beginning of meeting, and I think you may have missed 23 that part too.

24 (Simultaneous speaking.)

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109 MEMBER BLEY: I missed the first minute.

1 CHAIR SUNSERI: We'll have the transcript.

2 We can go back and look at his exact words, what he 3

said. We don't have to capture it all right here.

4 But if you want, just put a note for what the point is 5

and then we can do that.

6 VICE CHAIR REMPE: Guidance or regulation 7

may need to be modified or something like that, just 8

something about we understand why the staff did what 9

they did.

10 MEMBER MARCH-LEUBA: If I may say so, that 11 last statement should be a third bullet and really the 12 first and second are the same concept.

13 MEMBER KIRCHNER: Jose, yeah, we could 14 just keep them for now.

15 MEMBER MARCH-LEUBA: Okay.

16 MEMBER KIRCHNER: Offline, we can condense 17 and make sure we capture everything.

18 CHAIR SUNSERI: So once Dennis is done, 19 the next member would be Vesna.

20 MEMBER KIRCHNER: Yeah, Vesna, you had --

21 I know you have something you said perhaps written 22 down. But if you could just summarize it, we 23 certainly can collect from all members any input 24 offline. But for this purpose --

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110 MEMBER DIMITRIJEVIC: Yeah, this will be 1

difficult to dictate. So I'm just going to summarize 2

and then -- I mean, I have it written on my piece of 3

paper. I will start putting it in the vote, but I'm 4

not finished. So then I will send you the file.

5 MEMBER KIRCHNER: Summarize here and it 6

will --

7 MEMBER DIMITRIJEVIC: So main summary here 8

is the Chapter 19 on multiple places, thanks to Jose, 9

we have stated that we cannot make conclusions. And 10 the risk is properly identified and the safety goal is 11 met. And we cannot conclude the design is safe until 12 this boron thing is addressed, right? Everybody 13 remembers that, right?

14 (Simultaneous speaking.)

15 MEMBER DIMITRIJEVIC: So therefore, the 16 question is, how can we close the Chapter 19 if we 17 cannot really after this discussion say, oh, this is 18 not a risk concern? I don't think at this moment we 19 are ready to say this is not a risk concern. The main 20 of these things is because also the same thing, the 21 beginning of this meeting that we're going to clearly 22 identify scenarios leading to this boron power 23 excursion.

24 So I don't think we have succeeded in that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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111 either because those scenarios are not in this moment 1

clearly identified, at least not from my point of view 2

that I can feel comfortable that they don't present 3

significant risk concerns. I don't think that the 4

risk is as high as presented yesterday to us because 5

there is so many assumptions there that may be 6

questionable. The one other thing is the -- the one 7

important thing is for how long it takes to get in 8

this. What does it mean, prolong? How long is that?

9 And the second thing is, how would 10 operator make this error of commission? Is that 11 sabotage event? Does he have got the wrong 12 indication? Why would an operator when he has 13 successfully since he had decided to start, for 14 example, charging?

15 So then we haven't alternatively addressed 16 or discussed this operator action in order to estimate 17 how likely that action is or not likely. I mean, if 18 he wants to sabotage, he can withdraw the rods. I 19 mean, why would he do it? So then Jose's point is 20 then he tries to go in the different mode of 21 operation, the change the state, that he will be 22 instructed or required to do that. But we don't 23 really have operating procedures how to shut down or 24 in this moment. So we cannot deliberate what he's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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112 doing.

1 So therefore, in this moment, you cannot 2

really estimate how likely is the operator to make 3

this settle for this most likely state. That state, 4

there is so many things in there, and PRA scenarios 5

which have not been addressed. One of those is, for 6

example, if we have a charging break outside of 7

containment. Then the operator will definitely should 8

start.

9 After the ECCS operation and everything 10 goes, operator will start containment flooding and 11 drain system. And that could happen after prolonged 12 ECCS operation. Now I the PRA presentation, it will 13 say that the injection in this case is very low and 14 would not change. But we cannot see any relation of 15 that.

16 Also, this is happening not in ATWS 17 scenario. So this is happening in the all-rods-in 18 scenario. And this is a very important question for 19 me. What is a rod seam because having one rod out is 20 already getting your sequencing where the for rod four 21 orders of magnitude down.

22 So I just want to say that we have not 23 really defined scenarios. Definitely, there is no 24 support. The most -- the LOCA, I've been very 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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113 impressed with Pete, that it's all defined for small 1

LOCA and rod-out.

2 And the thing is that I don't think at 3

this moment I have enough conclusion to say that 4

Chapter 19 agrees that this is a low risk with a big 5

matching to the safety goals. And then we have 6

identified all risk in sight. And without discovering 7

recovery actions or the actions which can get us into 8

trouble, we cannot even -- in the Chapter 19, the 9

first table says that important risk inside should be 10 identified. And for example, I has a section on human 11 actions. Also, the human actions is important for the 12 risk should be identified.

13 However, in the text of Chapter 19, it 14 clearly says there is no important human actions.

15 There is no action of commission to be considered. We 16 have been complaining about that from the different 17 reasons. But when it comes to this boron, obviously 18 is Chapter 19 acceptable with the statements they 19 make?

20 So my point is that what we wrote in the 21 Chapter 19 letter, I'm not sure we can close in this 22 moment with the information which we have. And I'm 23 interested what other members think about how do we 24 proceed from now. But I will put a lot of those 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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114 things in the statement and then we can -- you guys 1

can consider them.

2 MEMBER PETTI: So Vesna, I have a 3

question. Are you saying -- you say we, so I'm a 4

little confused. Are you saying that the PRA missed 5

sequences of the kind that we are talking about --

6 that we've been talking about?

7 MEMBER DIMITRIJEVIC: No, what I'm saying 8

the sequences in the PRA exist, but they only --

9 success criteria is only make up, not the reactivity 10 excursion. They just consider are they on time to 11 cover the core, not the boron and the reactivity 12 insertions. They're not considered in any of those 13 scenarios.

14 MEMBER PETTI: So the phenomenology behind 15 the risk assessment --

16 MEMBER DIMITRIJEVIC: Yes.

17 MEMBER PETTI: -- is not correct?

18 MEMBER DIMITRIJEVIC: And I don't know if 19 it's correct. If this is -- if boron is not an issue, 20 then it's correct.

21 MEMBER PETTI: Right, right.

22 MEMBER KIRCHNER: So it may not be 23 complete.

24 MEMBER PETTI: Right. And I'm just trying 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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115 to figure out how to characterize that in my mind, 1

yeah. Thanks.

2 MEMBER DIMITRIJEVIC: So from that 3

perspective, actually if you control F boron dilution 4

in the Chapter 19, you will only find the very short 5

discussion about the deborated water, some simple 6

things. But no boron -- not any or no discussion at 7

all about this downcomer boron dilution.

8 MEMBER BLEY: And the things we heard 9

discussed this week aren't documented in the normal 10 place.

11 CHAIR SUNSERI: So Vesna, I have a 12 question.

13 MEMBER MARCH-LEUBA: We need to capture 14 that.

15 CHAIR SUNSERI: In my mind -- go ahead.

16 MEMBER MARCH-LEUBA: No, go ahead, Matt.

17 Finish it. But what I was saying is we need to 18 capture. There were two or three concepts, and we 19 need to capture them in bullets. And then both of 20 them or whatever, we'll write a letter. So I heard 21 there were two concepts. One is the boron dilution 22 topic is not properly captured in the PRA. This 23 dilution issue or topic is not properly captured in 24 the PRA.

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116 MEMBER DIMITRIJEVIC: Well, Jose, what 1

means properly? I mean, it's not captured.

2 (Simultaneous speaking.)

3 MEMBER MARCH-LEUBA: Okay.

4 MEMBER DIMITRIJEVIC: What do you mean 5

properly?

6 MEMBER MARCH-LEUBA: Yeah. Sandra, please 7

delete --

8 MEMBER DIMITRIJEVIC: Right now, we don't 9

have it properly to capture that.

10 MEMBER MARCH-LEUBA:

Please delete 11 properly.

12 MEMBER DIMITRIJEVIC: And because that's 13 a red box in Dave's diagram. So I don't know. Can it 14 be properly? Let me ask you something, Jose, because 15 I wanted to ask you that. Is this -- the prolong ECCS 16 dilution, is this also an issue if all rods are in?

17 I mean --

18 MEMBER MARCH-LEUBA: Yes, yes.

19 MEMBER DIMITRIJEVIC: -- the dilution is 20 going to happen, but can you add enough reactivity to 21 get in trouble?

22 MEMBER MARCH-LEUBA: Yes. What I --

23 MEMBER DIMITRIJEVIC: Even if all rods are 24 in?

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117 MEMBER MARCH-LEUBA: Even with all rods 1

are in, you will get critical. What I don't know 2

because a calculation has not been performed is if the 3

power will be high enough to cause damage to the core 4

because the calculation has not been performed. But 5

the reactor will go critical, yes.

6 MEMBER DIMITRIJEVIC: Pete has said in his 7

paper that even with one rod out, he will not go 8

critical. So now the question is --

9 MEMBER MARCH-LEUBA: And that's why I said 10 earlier before lunchtime I think he's being misquoted.

11 But we'll talk about that whenever Walt wants to talk 12 about it.

13 MR. LU: Yes, we have his white paper and 14 we can use that as a reference.

15 MEMBER MARCH-LEUBA: Yeah, but the white 16 paper is being misunderstood.

17 MEMBER DIMITRIJEVIC: Well, he has stated 18 that in his conclusions on Chapter 36, he said that 19 Doppler feedback, blah, blah, blah, that there will 20 not be any damage from the excessive energy 21 disposition.

22 MEMBER MARCH-LEUBA: Okay. I disagree 23 with that statement.

24 MEMBER DIMITRIJEVIC: I know, but this is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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118 another assumption that one rod is out, so --

1 MEMBER MARCH-LEUBA: Since we're talking 2

about this, Pete has not a single calculation to 3

support what you guys have said.

4 MEMBER DIMITRIJEVIC: Well, now let's ask 5

another question. How about the delay ECCS actuation?

6 Is there also, you think, enough criticality can be 7

added, because that's happened in that accident is the 8

all rods are in.

9 MEMBER MARCH-LEUBA: We can talk offline.

10 I haven't thought about that one. Critical delay ECCS 11 actuation means less deboration. But you have to tell 12 the specific transient.

13 MEMBER DIMITRIJEVIC: I will try to put 14 these things in the -- you are also aware that -- I 15 mean, I noticed you discussing this containment flood 16 and drain multiple times. You are aware that there is 17 actually scenario which is assume to lead to success.

18 When we have a break outside containment in charging 19 lines, so charging is not going to be insulated. Is 20 that operator still instructed to start containment 21 flood and drain after some time? That timing is not 22 defined in the PRA or in HRA, but it comes after 23 prolonged ECCS operation in my opinion.

24 MEMBER MARCH-LEUBA: I am willing, ready, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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119 and able to have an offline meeting with you. And you 1

ask me what your transient is, and I'll tell you what 2

I think happens. But right now, I haven't thought 3

about that one, so I don't have an answer.

4 MEMBER BLEY: This is Dennis. May I 5

interrupt the process question for Matt?

6 CHAIR SUNSERI: Yes, go ahead, Dennis.

7 MEMBER BLEY: Or Walt, I'm not sure who 8

this goes to. In two weeks, we're going to have 9

another meeting ostensibly to get three letters out.

10 But at least for me, the Dr. Lu paper and Peter 11 Yarsky's paper, I really can't say I've studied those 12 to the point that I'm comfortable drawing any 13 conclusions from them. I'm hoping we're planning at 14 least a half of day meeting back with the staff and 15 the applicant to discuss any issues we have been we 16 try to complete the letter. Is that true?

17 MEMBER KIRCHNER: Well, we haven't asked 18 them to make any formal presentations, Dennis. But 19 should the -- as a result of this process, if we feel 20 we need to request through Scott of support from the 21 staff and/or the applicant, I think we can do that.

22 So --

23 MEMBER BLEY: Well, I just --

24 CHAIR SUNSERI: I agree, Walt. What I 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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120 would suggest here is we get through the list of 1

things and then we identify where we feel like there's 2

holes in our knowledge that would be enhanced or 3

whatever, how you want to say it.

4 MEMBER KIRCHNER: Right, right. For the 5

presentations.

6 CHAIR SUNSERI: And be very specific on 7

what we want from them. I mean, that's where I would 8

go with it.

9 MEMBER KIRCHNER: Yes. Is that fair 10 enough, Dennis?

11 MEMBER BLEY: Yes.

12 MEMBER KIRCHNER: Yeah, because I just 13 don't want to just say, oh, we want presentations 14 again from the staff and the applicant, without the 15 specificity that Matt's referring to.

16 MEMBER DIMITRIJEVIC: Walt, just to wrap 17 it up, I don't think it's my job to make conclusion 18 that this is not a risk -- I can have more days to try 19 to estimate this. But that shouldn't be my job. The 20 main thing is the PRA made the point.

21 It says, in their opinion, the boron 22 dilution of downcomer is not a risk issue, period. So 23 now the only question is we can -- at least their 24 conclusions which I was trying to do and then say, do 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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121 we have enough to conclude that they made the right 1

conclusions? That's it. I mean, they have made 2

conclusions that this is not a risk issue in the 3

Chapter 19. Okay. That's it.

4 CHAIR SUNSERI: So Walt, if I were 5

following alphabetical order, you would be next. But 6

since you're the Chair --

7 MEMBER KIRCHNER: I'm going to pass, yeah.

8 CHAIR SUNSERI: -- you should go last so 9

as to not to unduly influence with the power of the 10 position, huh? How's that sound?

11 MEMBER KIRCHNER: Yes. What power of 12 position? Okay. I think Jose is next.

13 CHAIR SUNSERI: We'll go to Jose next, 14 yes.

15 MEMBER MARCH-LEUBA: Okay. Sandra, I 16 apologize. You're going to have to type a lot because 17 I have a five-page document I'm going to try to 18 summarize it in few words. So Sandra, are you ready?

19 Type, the design modifications solved the issue of --

20 solve, like in resolve. Okay. Solve the issue of 21 uncontrolled passive cooling and late ECCS actuation.

22 MS. WALKER: I'm sorry, Jose. I missed 23 that.

24 MEMBER MARCH-LEUBA: Yeah. So self 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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122 control is uncontrolled, U-N controlled, lack of 1

control, uncontrolled, uncontrolled. We know anyway.

2 No. Type where you are. Type, late ECCS actuation.

3 I think we know what we mean.

4 MEMBER KIRCHNER: Yeah.

5 MEMBER MARCH-LEUBA: Go to the next one.

6 Next -- not accusation. Okay. We know what we mean.

7 Okay. Keep typing. Next bullet. The design 8

modifications actuation. Are you ready? The design 9

modifications do not prevent and type upper case DC 10 for downcomer, D-C, deboration. Okay.

11 And can you move backwards? It shouldn't 12 say, do not prevent. Say, do not completely prevent.

13 Next bullet. The applicant and the staff argue that 14 no mechanism exists to drive deborated DC water into 15 the core. Deborated, D-E-B-O-R -- okay. Unborated, 16 say unborated. Okay. It's good. Deborated water --

17 MEMBER KIRCHNER: Jose? Jose?

18 MEMBER MARCH-LEUBA: -- into the core.

19 MEMBER KIRCHNER: Jose, I don't think they 20 quite say that. They kind of say --

21 MEMBER MARCH-LEUBA: We'll argue that 22 after I type it, and we will --

23 (Simultaneous speaking.)

24 MEMBER KIRCHNER: All right. All right.

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123 But I'm just trying to be factual. I'm not trying to 1

debate positions. Okay.

2 MEMBER MARCH-LEUBA: Deborated water into 3

the core and cause damage, period. We believe -- no, 4

don't put believe. Can you delete that, please? No 5

calculations support this statement. All right.

6 That's good. Let's move to the next. I will skip 7

recovery because we already covered it.

8 MEMBER KIRCHNER: Jose, would you let me 9

just make a suggestion?

10 MEMBER MARCH-LEUBA: Yes, sir.

11 MEMBER KIRCHNER: I know where you're 12 going with that previous bullet. They actually do 13 look at -- it's the latter part of your bullet that's 14 operative here. They don't believe that they would 15 experience any core damage. I don't think they ever 16 said that no deborated water would find --

17 MEMBER RICCARDELLA: Walt --

18 MEMBER KIRCHNER: -- its way to the core.

19 MEMBER RICCARDELLA: -- how about if you 20 put the word, significant, before deborated?

21 MEMBER MARCH-LEUBA: Yeah, I thought --

22 MEMBER RICCARDELLA: Would exist to drive 23 24 MEMBER MARCH-LEUBA: -- what I typed --

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124 MEMBER RICCARDELLA: -- significant 1

amounts of deborated water into the core.

2 MEMBER MARCH-LEUBA: Yeah.

3 (Simultaneous speaking.)

4 MEMBER MARCH-LEUBA: I mean, in my 5

statement, I was saying that no mechanism exists to 6

inject sufficient deborated water into the core to 7

cause damage.

8 MEMBER RICCARDELLA: Yeah, there you go.

9 There you go.

10 MEMBER MARCH-LEUBA: That's what I was --

11 (Simultaneous speaking.)

12 MEMBER KIRCHNER: That's better. That's 13 better because they did look at it. We need to be 14 factual.

15 MEMBER MARCH-LEUBA: On the next line, can 16 you instead of say, and cause damage, can you say, to 17 cause damage? After core, instead of, and cause 18 damage, say, to cause damage on the last line.

19 MS. WALKER: I'm sorry. On the last line?

20 MEMBER MARCH-LEUBA: Yeah. On the fifth 21 one, on the last line, it says, water into the core 22 and cause damage.

23 MS. WALKER: Okay.

24 MEMBER MARCH-LEUBA: It should say, water 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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125 into the core to cause damage.

1 MS. WALKER: Okay, sorry.

2 MEMBER MARCH-LEUBA: Hey, take a little 3

break. Can you go into layout and put line numbers?

4 So that way, we can tell you where to go. All right.

5 New paragraph, line 23. No instrumentation exists to 6

measure boron redistribution, period. The existing 7

instrumentation -- no, no, the same paragraph. The 8

existing instrumentation may not be operable under 9

ECCS conditions, under, under. You know what I'm 10 doing. This is just a reminder.

11 New paragraph. The void reactivity 12 coefficient -- the void, V-O-I-D, bubbles, bubbles, 13 reactivity coefficient has not been calculated, 14 period. These conditions are an unusual geometry, and 15 the possibility of a positive coefficient -- the 16 possibility of a positive being greater than zero --

17 positive coefficient cannot be discarded without a 18 calculation.

19 MEMBER KIRCHNER: Jose, while this --

20 MEMBER MARCH-LEUBA: Yes.

21 MEMBER KIRCHNER: -- being typed, just an 22 observation. I know this is not our final letter.

23 I've learned over the years to not use no, never, or 24 all. Instrumentation does exist, but I'll let this 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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126 pass for the time being. I know the point you're 1

trying to make.

2 MEMBER MARCH-LEUBA: Boron redistribution 3

will require multiple locations to measure the boron.

4 We only have one --

5 MEMBER KIRCHNER: But we're saying --

6 MEMBER MARCH-LEUBA: -- that one doesn't 7

work.

8 MEMBER KIRCHNER:

here no 9

instrumentation exists. And there is only --

10 unfortunately, only one-point

sample, if it's 11 operable.

12 MEMBER MARCH-LEUBA: Yeah, yeah. Sandra, 13 on Line 23, can you say, no effective instrumentation 14 exists on Line 23?

15 MEMBER KIRCHNER: I'm not going to debate 16 these, Jose. I just wanted for the record to make it 17 clear that we're just capturing thoughts here. This 18 is not a final statement or position by the Committee 19 by any means.

20 MEMBER MARCH-LEUBA: All right. Sandra, 21 final paragraph and you're almost done with me. Yeah, 22 type, Chapter 19 of the SER states that CFDS -- F-D-S 23

-- operation is not a risk concern, period. No 24 calculation is provided to support it.

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127 Instead of is, can you say, has been on 1

the other line, 29? No calculation has been provided.

2 And I don't know if -- thank you, Sandra. I'm asking 3

Vesna now. Did you already make the point that they 4

claim that no operator errors of commission can 5

possibly do any damage to the core? And that is on 6

the

SER, and I

think that's unsupported by 7

calculations.

8 MEMBER DIMITRIJEVIC: They didn't make any 9

claims on the boron event.

10 MEMBER MARCH-LEUBA: No, no, not boron 11 dilution. On the generic Chapter 19, I believe they 12 say --

13 MEMBER DIMITRIJEVIC: Yes.

14 MEMBER MARCH-LEUBA: -- look at the 15 possible --

16 (Simultaneous speaking.)

17 MEMBER DIMITRIJEVIC: No, they say they 18 didn't identify any errors of commission, and we 19 argued that on the crane operation. But no discussion 20 was connected to the boron.

21 MEMBER MARCH-LEUBA: I am concerned of all 22 the operator errors of commission of starting these 23 nonsafety grade systems, especially if incorrect 24 information is provided in the FSAR to the COL. The 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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128 FSAR states in many places that CFDS can be used as a 1

backup for CVCS, many places. And now they're telling 2

us that to the COL, we will actually do this 3

calculation and find out if we were wrong. But that 4

statement is not supported by calculations. But I'll 5

leave that to you, Vesna. I'm done.

6 MR. MOORE: Jose, this is Scott.

7 (Simultaneous speaking.)

8 MR. MOORE: Yeah, this is Scott. On Line 9

15, Jose, did you want and control to be uncontrolled?

10 MEMBER MARCH-LEUBA: Yes, can you -- yes.

11 And Sandra, can you delete and? And by that, it's the 12 generic DHRS actuation. But most people don't know 13 what DHRS is, so --

14 MEMBER KIRCHNER: Yeah, and I cautioned 15 everyone that these are not statements from the 16 Committee. We're just gathering input, and we're not 17 going to edit them in real time to make them perfect.

18 This is not a Committee letter. We're just gathering 19 input. So I think --

20 MEMBER MARCH-LEUBA: And for the record, 21 what I mean by uncontrolled, I mean hands off.

22 MEMBER KIRCHNER: Yes.

23 MEMBER MARCH-LEUBA: It's passive. The 24 operator doesn't touch it.

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129 MEMBER KIRCHNER: Yeah. Okay. Thank you, 1

Jose. On the roster, I think Dave Petti is next.

2 MEMBER PETTI: I'm not exactly sure what 3

to say. I will tell you that I am concerned about a 4

couple of things. The staff made a reasonable 5

assurance finding. Some of these bullets imply they 6

didn't do their job properly because they didn't do a 7

calculation. They did an assessment, an engineering 8

assessment. You could argue whether that's good 9

enough or not. But the implication based on the words 10 is that they were somehow negligent in their --

11 MEMBER KIRCHNER: No, so Dave, let's 12 capture this. I don't want to collect a lot of 13 negatives. I want to collect just issues that were of 14 concern. So you're concerned that we're overreacting 15 or overstating the case, let's capture it.

16 MEMBER PETTI: Yes, that's the concern, 17 Sandra, is that the statements are overly negative 18 relative to the staff's reasonable assurance finding 19 and the engineering assessments that support that. I 20 did write some words that you all saw that tried to be 21 more balanced in this regard. But we can take those 22 offline later.

23 In my opinion, what we're down to is 24 differences of opinion between two experts -- two or 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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130 three experts, Dr. Yarsky, Jose, and whose name I 1

can't remember, the dissenting opinion.

2 MEMBER RICCARDELLA: Dr. Lu.

3 MEMBER PETTI: Dr. Lu. Thank you. So --

4 MEMBER MARCH-LEUBA: I cannot run the 5

calculations for them. All I know --

6 (Simultaneous speaking.)

7 MEMBER PETTI: But you are dismissing the 8

role of engineering assessment. If you --

9 (Simultaneous speaking.)

10 MEMBER PETTI: It would be -- I don't mind 11 a statement that says, a calculation to confirm or 12 deny the engineering assessment would be very 13 valuable. But when you say, this isn't supported, 14 this isn't supported, this isn't supported, it makes 15 it sound like they didn't do a damn thing for the last 16 four weeks. These guys have been busting their butt 17 to try to get this done, I'm sure working night and 18 day.

19 And that's what I'm concerned about is the 20 tone of the letter, how it can be misinterpreted, 21 because you know people are looking. They've already 22 been looking at our previous letters in the press. We 23 have to be extremely careful with how we craft the 24 picture.

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131 I agree with the item on Line 3. We 1

should -- it'd be nice to have a well identified 2

recovery path. I don't think any of us disagree with 3

that. But there's not enough information to, I think, 4

meat the well identified path at this point.

5 MEMBER MARCH-LEUBA: The problem, Pete --

6 I mean, Dave, is that the argument for saying that 7

CFDS has no risk concern when you go to bottom -- and 8

I talked to the staff, Pete, and the applicant. And 9

their argument is in their mind, they honestly believe 10 that the core will mix. There will be sufficient 11 turbulence to mix the front, and the front won't 12 exist.

13 That's their bottom line argument because 14 if they're calculation with the front moving through 15 the core unimpeded and clean, not mixed, they cannot 16 support it. So that's their argument. Their argument 17 is it will mix, but they haven't written that 18 anywhere. They don't even make that argument, not 19 even in oral arguments. Well, they do. And how do 20 you calculate that? So their argument --

21 MEMBER PETTI: I see them --

22 MEMBER MARCH-LEUBA: -- of CFDS --

23 MEMBER PETTI: -- make that argument in 24 the white paper.

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132 MEMBER RICCARDELLA: Yeah, the white paper 1

makes that argument, Jose.

2 CHAIR SUNSERI: Jose, you've made that 3

point. We understand that. We get it. Saying it 4

over and over again is not helping any. It's impeding 5

Dave's ability to get his points on the table. Let 6

Dave get his points on the table. Go ahead, Dave.

7 MEMBER KIRCHNER: Go ahead, Dave.

8 MEMBER PETTI: I think that's the major 9

point beyond what's in the email that you guys have 10 that to get to a well identified recovery path I think 11 is going require analysis of the stuff in the red box 12 that we talked about this morning. That isn't going 13 to happen quickly. We talked about that.

14 MEMBER BALLINGER: This is Ron. I guess 15 I was the one that put the statement on Line No. 3.

16 I think we have to be satisfied in our minds that 17 there's a well defined recovery path. I don't know 18 that they need to write it down and make sure and show 19 it to us. I mean --

20 MEMBER PETTI: So a strategy --

21 MEMBER BALLINGER: -- somehow we need to 22 be --

23 MEMBER PETTI: -- perhaps is really --

24 MEMBER BALLINGER: Yeah, in other words, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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133 we need to be satisfied that down the line when they 1

build one of these things, somebody says, oh, my gosh.

2 We can't recover. So we need to be satisfied, I 3

think, that a recovery path exists. That's what I was 4

trying to get at.

5 MEMBER PETTI: Yeah, and I don't disagree 6

with that. The question is, I mean, and this gets 7

into this legalistic thing, now or before, is it a 8

high COL item?

9 MEMBER KIRCHNER: Dave, any further 10 comments?

11 MEMBER PETTI: No.

12 MEMBER KIRCHNER: Okay. I'm thinking 13 alphanumerically here.

14 CHAIR SUNSERI: Hold on a second. Did we 15 get that? Did we get that?

16 MEMBER KIRCHNER: Did we get what you 17 wanted, Dave?

18 MEMBER PETTI: Yeah, that's fine.

19 MEMBER KIRCHNER: Okay.

20 CHAIR SUNSERI: Okay. Joy would be next.

21 MEMBER KIRCHNER: Joy would be next.

22 VICE CHAIR REMPE: Okay. So rather than 23 start something who I guess I -- I'll tell you what 24 I'm trying to say. You tell me whether how to best do 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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134 it. In a way, it's kind of building off of your 1

chart, Dave, and some other things that I heard. But 2

if I hadn't seen other people's input, it's difficult 3

to have in my opinion from what I've heard.

4 It's difficult to obtain -- it may be 5

difficult to have a well justified recovery path 6

because, one, we didn't see a write up that was 7

documented and available for us to review. And in my 8

opinion, it may be difficult to actually -- detailed 9

codes may not be available that are validated. And we 10 sent an awful lot of time arguing about engineering 11 judgment or expert opinion.

12 And so yeah, you might say it's a COL 13 item. But on the other hand, I'm thinking that we're 14 kind of just touching the tip of what they're going to 15 have to deal with in the future. And you could almost 16 put it as an add on to Ron's point on Line 3 that it 17 may be difficult to resolve with available validated 18 methodologies. Is that going to be offensive to you, 19 Ron, if I add something like that there?

20 MEMBER RICCARDELLA: I'm impossible to 21 offend.

22 VICE CHAIR REMPE: That's good to know.

23 I'll try and use that --

24 (Simultaneous speaking.)

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135 MEMBER BALLINGER: I've been offended by 1

professionals. You can't do anything.

2 VICE CHAIR REMPE: Ooh, I could try. It's 3

a challenge. On your thing about the existing 4

instrumentation, I know you're talking about boron 5

distribution. And I heard Matt earlier today talking 6

about, well, the operators can infer it from the flux 7

monitors.

8 And if you've got chugging going back and 9

forth, the kicker I'm trying to get to is that they're 10 going to have to infer what's need. And it may be 11 more difficult because not only you may have changes 12 in your boron distribution, but I'd also think you 13 might be having fluctuations in the water itself. And 14 so -- and that's kind of also talking about a well 15 identified recovery path. It could be also difficult 16 to infer what's needed. And I don't know whether you 17 want to add that to your point, Jose, on 22. Or just 18 it's not only validated (audio interference) but with 19 existing --

20 MEMBER MARCH-LEUBA: I see --

21 VICE CHAIR REMPE: -- available plant 22 instrumentation.

23 MEMBER MARCH-LEUBA: I see where you're 24 going. The only possible way out they have without 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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136 thinking much about it because they have not thought 1

much about it and we're thinking at a COL stage. They 2

say that we can use the period-based trip -- or not 3

trip. In this case, it would be an alarm to identify 4

criticality and then we would stop.

5 I don't know what the inertia will do.

6 And certainly it raises significant questions about 7

GDC-27, a return to power. And especially from the 8

point of view of HRA, human reliability assessment, 9

that's not a simple operation that you can give ten to 10 the minus four probability that the operator will do 11 right.

12 VICE CHAIR REMPE: Well, if you're --

13 (Simultaneous speaking.)

14 VICE CHAIR REMPE: -- what they're going 15 to do with existing instrumentation for a different 16 application and I can think about what we tried to do 17 with the SPNDs at TMI to understand when the core was 18 relocating or what we're trying to do at Fukushima, a 19 lot of variables. It's not so easy. And so it's 20 going to -- so you can decide where to put it, but --

21 (Simultaneous speaking.)

22 MEMBER MARCH-LEUBA: It is conceivable 23 that the operator will thread the needle and do it 24 right. But it's not inconceivable that one of those 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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137 ten times, he'll do it wrong.

1 (Simultaneous speaking.)

2 VICE CHAIR REMPE: Anyway, so I don't 3

know. Do you want to add it on to yours? I mean --

4 MEMBER MARCH-LEUBA: Okay. You do it.

5 VICE CHAIR REMPE: -- you're talking about 6

boron distribution.

7 MEMBER MARCH-LEUBA: I've been putting in 8

too much stuff.

9 VICE CHAIR REMPE: Okay. Well, maybe 10 we'll just add it on number 3. And Sandra, right now, 11 maybe I have a slow response this time. But I just 12 see validated. So why don't you say, validated 13 analysis codes. Okay? Maybe you're doing it, Sandra, 14 but my computer is not -- I see something happened.

15 Yeah, there it is.

16 And existing plant instrumentation. And 17 then because we spent so much time arguing about 18 expert opinion or engineering judgement, maybe put in 19 parenthesis there's variability with experts and 20 engineering judgement and you get my point. I mean, 21 bring in a new set of experts and you get a different 22 answer.

23 MEMBER KIRCHNER: Well, that always is 24 true. I don't that's going to find its way into our 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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138 letter.

1 VICE CHAIR REMPE: I know, but I've 2

listened to many arguments between experts this week.

3 It's just my own frustration. Anyway, go ahead.

4 MEMBER KIRCHNER: Well, what was relevant 5

to that, Joy, again, on a factual level is whether 6

there was an issue about the PERT that was used for 7

the PRA. And that's where there was perhaps something 8

was missed. But generically, I don't think we want to 9

take that topic on.

10 VICE CHAIR REMPE: Well, right now, you're 11 talking about -- I've heard today about, well, they 12 used engineering judgment. And again, engineering 13 judgment, unless it's just so obvious, undocumented 14 engineering judgment or that we couldn't review is 15 difficult to have confidence. Okay? How about that?

16 MEMBER KIRCHNER: Just be careful you 17 don't undermine the Committee.

18 VICE CHAIR REMPE: Good point.

19 (Simultaneous speaking.)

20 VICE CHAIR REMPE: Maybe that's another 21 point. Anyway, I said enough. Maybe put in 22 parenthesis, engineering judgment, and I'll let the 23 letter writers figure out what to do with that.

24 MEMBER BALLINGER: You know, folks, that's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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139 always our opinion. It's always our engineering 1

judgment.

2 CHAIR SUNSERI: That's why we were chosen 3

hopefully.

4 MEMBER BALLINGER: That's why we were 5

chosen.

6 CHAIR SUNSERI: I'm going to turn from Joy 7

to Matt Sunseri.

8 (Simultaneous speaking.)

9 MEMBER KIRCHNER: Oh, no. Wait a minute.

10 My alphabet is scrambled today. Pete Riccardella?

11 MEMBER RICCARDELLA: Yeah, I had --

12 MEMBER KIRCHNER: Could you do the Italian 13 pronunciation for us, Pete?

14 MEMBER RICCARDELLA: Riccardella. That 15 was the Italian spelling before my ancestors ended up 16 at Ellis Island or wherever it was. Anyway, it's --

17 I had a bunch of points, but most of them, I think, 18 have been covered. I'd just maybe add to couple of 19 them in what was Line No. 8. Now it's, I guess, No.

20 9.

21 To me, at the end of that, there's --

22 after it says, how much of what we're talking about is 23 required to demonstrate adequate protection at the DCA 24 stage? How much of the analysis in that red box is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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140 really required at this stage I'm asking. And then 1

kind of along the lines of what Joy was talking about, 2

all these lines where we talk about no calculations 3

have been done, no calculations have been done. But 4

there has been what I think is a very impressive 5

engineering judgment, a 30-page white paper by an 6

expert in the field.

7 And I don't think we should just discount 8

that as, oh, there's no calculations, no hard 9

calculations. I read that report and admittedly not 10 an expert in that area, but it was very convincing to 11 me. So somehow no calculations, but a well documented 12 engineering judgment.

13 MS. WALKER: What was the last part?

14 MEMBER RICCARDELLA: Engineering judgment.

15 That's all I have.

16 MEMBER MARCH-LEUBA: Sorry, Pete. But I 17 need to again emphasize that I strongly disagree with 18 one of Pete's conclusions. I think he would agree 19 with me if he was informed. He did not say that when 20 you turn CFDS, you won't have a problem if you inject 21 cold unborated water all the way to the top of the 22 core. What is he said is he believes, engineering 23 judgment, that the water will mix and won't cause the 24 problem.

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141 MEMBER RICCARDELLA: You know --

1 MEMBER MARCH-LEUBA: But --

2 MEMBER RICCARDELLA: -- his engineering 3

judgment all involves the required calculations in 4

that red box and Dave's charts. And he's made some 5

engineering judgment about that. And I think, Jose, 6

that you and Dr. Lu are kind of ignoring that red box 7

and just saying, well, they haven't done the 8

calculations, so we're just going to assume that it 9

all goes in there. And he's tried to explain, I 10 think, based on his best judgment what will happen in 11 that red box.

12 MEMBER MARCH-LEUBA: Right. But when 13 you're taking credit for mixing because of turbulence 14 in the core, that's a stretch, man. And I'll stop 15 there.

16 MEMBER RICCARDELLA: He's taking credit 17 for that. He's taking credit for negative reactivity 18 coefficients, both Doppler and void coefficients.

19 MEMBER MARCH-LEUBA: Which he doesn't --

20 MEMBER KIRCHNER: I would just prefer that 21 nature -- Jose, nature isn't very kind. If you try 22 and propagate a level front of almost anything in a 23 liquid system, it's only with great difficult. If you 24 had oil and water, might be a little easier. They 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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142 tend to separate. Otherwise, Second Law of 1

Thermodynamics, entropy, things mix.

2 MEMBER MARCH-LEUBA: I know it will mix 3

with what's in the core. But there are 14 times more 4

core volumes going behind it. Okay. I said enough.

5 I mean, I agree with Pete. This is likely to be the 6

answer. I just don't see any justification that it 7

is.

8 MEMBER KIRCHNER: Okay. That argument, 9

we've heard now. I think, Chairman Sunseri, it's your 10 turn.

11 CHAIR SUNSERI: Thank you, Walt. And I 12 think most of what I have to say is covered within 13 these bullets. But I just want to make sure that we 14 emphasize or that we at least address a balance 15 between reasonable assurance and absolute assurance 16 and that our letter strikes the right tone.

17 And what I mean by way of an example is I 18 know we're concerned about the evaporation of the 19 water out of the core. We know the scenario, right?

20 It condenses in a downcomer. It dilutes there. And 21 then we're worried about recovery about that.

22 I can think back on my experiences with 23 PWRs advance sequence where you lose natural 24 circulation cooling during some kind of loss of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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143 coolant accident. The steam generate U-tubes uncover 1

and you are in the exact same situation as here. The 2

core is heating up. The water boils. The steam goes 3

up in the steam generator tubes, condenses, falls down 4

the cold leg side of the coolant system, feeds the 5

manometer. And that diluted water then starts 6

migrating back to the core, and we count on that for 7

core cooling in that situation.

8 If we can -- and we can recover from that 9

situation. And I think there's sufficient evidence 10 that we can recover from this situation in the NuScale 11 model. And that's all I want to say at this time, and 12 I'll just leave it at that.

13 MEMBER KIRCHNER: Thank you, Chairman.

14 MEMBER PETTI: Walt --

15 (Simultaneous speaking.)

16 MEMBER KIRCHNER: So I think --

17 MEMBER PETTI: Walt, can we just capture 18 one other thing. I mean, I said it, but we were 19 talking fast.

20 MEMBER KIRCHNER: Go ahead, Dave.

21 MEMBER PETTI: I just think a statement 22 about the tremendous amount of work that both the 23 staff and applicant have put in.

24 MEMBER KIRCHNER: I'm going to close with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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144 that, Dave.

1 MEMBER PETTI: Okay.

2 MEMBER KIRCHNER: Thank you for the 3

prompt.

4 MEMBER PETTI: Thanks.

5 MEMBER KIRCHNER: Okay. So I get to that 6

clean up. I personally -- and I'm going to do 7

something I never do, but I'm going to do it today.

8 I'll use the never word. I was the reactor design 9

group leader at Los Alamos for quite a few years in 10 the '80s. I just put that on the table because I had 11 the great fortune to look at a lot of different 12 reactor designs.

13 I worked for the NRC on the module HTGR, 14 the PRISM reactor and so on. And we designed heat 15 pipe reactors. We may see them very shortly. There's 16 an application that's been accepted by the Commission.

17 So I have that background. And so I want to say this 18 statement first.

19 In the context of 10 CFR 52, this is as 20 essentially complete design as we're likely to see.

21 We know that some of the applicants coming are going 22 to try and use 10 CFR 52. There is -- if you pardon 23 me, staff, there's what I would call a loophole that 24 allows novel designs that have enhanced safety 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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145 features, et cetera, to also apply under 10 CFR 52.

1 But this NuScale design I find pretty sound and 2

essentially complete. That's the words out of 10 CFR 3

52.

4 MEMBER PETTI: Walt, should Sandra capture 5

that point?

6 MEMBER KIRCHNER: Excuse me?

7 MEMBER PETTI: Should Sandra capture that 8

point? The NuScale design --

9 MEMBER KIRCHNER: Yeah, please, Sandra.

10 MEMBER PETTI: A complete DCA.

11 MEMBER KIRCHNER: This is an essentially 12 complete design in the spirit of 10 CFR 52. Spirit is 13 not the right word. In the context, please, of 10 CFR 14 52, this is an essentially complete design. It has 15 large margins compared to the existing fleet. And 16 with regard to -- now this may be better part of the 17 final letter, not the boron dilution letter. But let 18 me start with this, and then I'll narrow down my 19 comments.

20 It has large margins compared to the 21 existing fleet. Now don't type anything yet, Sandra, 22 because I haven't condensed this. But I see just this 23 one remaining issue that we've been engaged in this 24 last couple of days and for the last several months.

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146 I think basically maybe you could type now, Sandra.

1 Design changes and set point changes have 2

addressed long-term cooling under DHSR, that's an 3

acronym, capital D, capital H, capital R, capital, 4

DHRS conditions. Our remaining concern -- this is 5

more an opinion. But the concern -- yeah, just our 6

remaining concern is boron dilution after ECCS 7

actuation.

8 And now don't type anything, Sandra. I'm 9

just going to make a statement. This is the third 10 time I'm going to say it and the last. The staff 11 presented figures of merit which I think are 12 appropriate for this situation and in a way kind of 13 address what Dennis was saying about completeness of 14 the Chapter 15 analyses.

15 With regard to the DHRS, they were able to 16 demonstrate and confirm the applicant's position that 17 out to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, there was sufficient margin versus 18 critical boron concentration in the downcomer to 19 prevent the potential for a reactivity insertion 20 accident. That was good. It just begged from me 21 personally the question, where's the analysis on the 22 other side of the ledger?

23 Like, think about Dave's diagram. So he 24 checked the box, okay, on the left-hand side. Now 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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147 we're on the right-hand side. We're under -- ECCS is 1

actuated. We're under conditions that could lead to 2

long-term boration. Both the applicant and the staff 3

suggest that that could take place within -- going to 4

Vesna's comments. Time frame, Vesna. Time frame is 5

hours. It's not 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

6 And so in my opinion, there is a 7

successful recovery path. And the path is based on 8

conservative analysis to just either -- I would do it 9

in tech-spec space. But hopefully down the road, 10 they'll do it in an operational procedure or EOP space 11 that within X time frame, and this can be estimated 12 with conservative margin, thou shall, if it's 13 available, start with the preferred option, CVCS if 14 it's not injection above the -- in the riser.

15 Second, spray. And third, containment, 16 flood and drain system and intercept this before the 17 conditions come to a situation where your downcomer 18 dilution is greater than the critical boron 19 concentration for the core. And then --

20 MEMBER PETTI: So Walt --

21 MEMBER KIRCHNER: Let me finish.

22 MEMBER PETTI: Okay.

23 MEMBER KIRCHNER: I love calculational 24 space. I was an original member of the team that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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148 developed TRAC which is now TRACE. I'm very pleased 1

that almost 50 years later, it's still in use. I have 2

a lot of confidence in what can be done in 3

computational space.

4 But I would rather -- as Dave had 5

eloquently said or someone else, I don't want to be in 6

the red box. All I want to do is avoid getting to 7

this situation. I personally believe it can be done.

8 And so again, from my standpoint, an adequate safety 9

determination could be made. And that's the end of my 10 speech.

11 MEMBER PETTI: So Walt, to make sure I 12 understand what you're saying is think about a part of 13 the boron concentration in the downcomer after 14 actuation. It's decreasing. It's decreasing. It's 15 decreasing. There's a window where you need to get in 16 there and do the things you suggest so you don't get 17 into --

18 MEMBER KIRCHNER: Exactly.

19 MEMBER PETTI: -- below a critical level.

20 MEMBER KIRCHNER: I'm an engineer. I want 21 to prevent this situation. I don't want to try and 22 manage it.

23 MEMBER PETTI: I think we should capture 24 that.

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149 MEMBER KIRCHNER: There is a window. It 1

doesn't happen instantaneously. You don't have ECCS 2

actuation and then entire boron, as Jose was saying, 3

14 volumes of the core diluted. That takes time. You 4

have time to react. I have confidence that they can 5

do it.

6 I don't want to get into the detailed 7

procedures. But I do believe that in calculational 8

space with conservative assumptions, much like the 9

applicant and the staff used, one can make an estimate 10 of the time window that's available to intervene 11 before you come close to conditions that would 12 threaten the possibility of a reactive insertion 13 accident. And then we don't have to argue about 14 whether the wavefront is purely diluted, whether 15 there's mixing in the core, and all these other 16 aspects of the problem which are very complex 17 calculations.

18 MEMBER PETTI: So Walt, can you --

19 MEMBER KIRCHNER: But I don't want to do 20 that.

21 MEMBER PETTI: Can you dictate a sentence 22 to Sandra so we don't lose it?

23 MEMBER KIRCHNER: Go ahead, Dave.

24 MEMBER PETTI: Okay. I'll try. A window 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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150 of time exists following ECCS actuation for operator 1

actions to assure boron dilution does not decrease 2

below critical core concentration.

3 MEMBER MARCH-LEUBA: It's called the 4

critical boron concentration.

5 MEMBER KIRCHNER: Yeah, critical boron 6

concentration is the vernacular.

7 MEMBER PETTI: Right.

8 MEMBER MARCH-LEUBA: Which I remind 9

everybody that it's just a few percent from nominal.

10 I cannot tell you the exact number, but it's not very 11 large. And for this window, it might be minutes. And 12 I would like to ask you guys what power I'm going to 13 use to fix this.

14 MEMBER PETTI: Let me just finish. It's 15 concentration, yeah. Conservative calculations need 16 to be performed. Conservative calculations need to be 17 performed to determine the time window for such 18 recovery actions.

19 MEMBER KIRCHNER: And then finally, as a 20 former operator as well, I would not want to have to 21 rely on the source instrumentation. If we get into a 22 situation where this is feasible, there's inertia and 23 fluid dynamic effects. You, as an operator, will not 24 react fast enough to -- and you don't have much to --

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151 actually, what are you going to do, stop a boron 1

injection? It's a nice theory, but I don't think it 2

will -- if you just examine it from a few different 3

perspectives, yeah, the source --

4 MEMBER MARCH-LEUBA: I agree. It is --

5 MEMBER KIRCHNER: -- centers will tell you 6

went critical. But you know what? It's too late. So 7

you don't want --

8 MEMBER MARCH-LEUBA: Yeah, it will take at 9

least a minute or two to stop the flow.

10 MEMBER KIRCHNER: Yeah, yeah. You've got 11 flow in the pumps. The pumps -- or you isolate --

12 there's still flow in the system. That's not -- you 13 can't sit there with a delicate balance and then just 14 say, I'm going to look at the source term measurements 15 and control this situation. Trust me. Look into it.

16 Think about it. You'll figure out why --

17 VICE CHAIR REMPE: I agree.

18 MEMBER KIRCHNER: -- it's not feasible.

19 VICE CHAIR REMPE: Absolutely, Walt, what 20 I was trying to get to earlier. You just can't rely 21 on it.

22 MEMBER MARCH-LEUBA: I mean, you can rely 23 if it's the only thing you got. Okay? But that will 24 require throttling the CFDS injection to ten percent 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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152 or something. There will have to be an analysis and 1

the operator will have to be with the bottom at the 2

stop. I mean, plus, he have all the GDC-27 --

3 MEMBER KIRCHNER: They're not calibrated 4

for that. They're not -- it's just not a viable 5

option. Trust me.

6 VICE CHAIR REMPE: And they have voiding 7

to consider as well as boron concentration. So how do 8

you distinguish what's causing it?

9 MEMBER KIRCHNER: It's just not -- that's 10 not a credible option. I like what the applicant is 11 doing. I mean, prevention is the best cure for any of 12 these kind of events.

13 MEMBER PETTI: Stay out of the box.

14 MEMBER KIRCHNER: Stay out of the box. Do 15 not put yourself into a situation. Now I do not know 16 whether this is tech-spec space or EOP space. I would 17 like to see -- this is not a wish list thing. It may 18 exist. But I mean, what one can do clearly is 19 calculate very conservatively the deboration rate and 20 whether it's minutes as Jose suggested. It may depend 21 on the scenario that got you there and so on.

22 It may be hours. I think in most events, 23 it will be hours. But I haven't looked at the 24 spectrum of initiating events that you would consider.

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153 But it's like going through a spectrum of small-break 1

LOCAs to see what's the limiting --

2 MEMBER MARCH-LEUBA: Well, we're not 3

supposed to be deciding the reactor agenda.

4 MEMBER KIRCHNER: I'm trying to solve the 5

problem.

6 MEMBER MARCH-LEUBA: Okay. But the 7

critical boron concentration is just a few percent 8

below the nominal. It is minus, believe me.

9 If you use any conservative analysis, I 10 think you'll see --

11 MEMBER KIRCHNER: I don't know, Jose. Let 12 them analyze the problem. Let them tell us what the 13 distribution is in the lower --

14 MEMBER MARCH-LEUBA: That's what I've been 15 screaming at the top of my lungs. I don't know what 16 the answer is.

17 MEMBER KIRCHNER: Okay.

18 MEMBER MARCH-LEUBA: All I know is nobody 19 else does.

20 MEMBER KIRCHNER: But, well I don't know 21 that. I'm not going to say that.

22 MEMBER MARCH-LEUBA: I know that. Because 23 if they knew, it was an only --

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154 use the no, all never. That's an allegation, not a 1

fact.

2 All I can say is, there is a way to 3

determine a path out of this problem. And that's my 4

suggestion.

5 MEMBER MARCH-LEUBA: Let me put a request 6

to all the world that this is really distressing. If 7

you have a calculation that shows that this is not a 8

problem, please let me know.

9 Because I don't have it.

10 MEMBER KIRCHNER: No, no, no. No, Jose, 11 that's not -- that's not where I'm coming from. I 12 don't want to do the wave front going into the core 13 calculation and argue with you about void fraction 14 feedback and all the rest.

15 I want to avoid that. What I want to say 16 is, there is a pathway to determine when I don't have 17 sufficient boron in the downcomer. And I need to 18 intervene in the situation and take action.

19 And then I'm not going to bother about 20 analyzing the worst case scenarios.

21 MEMBER MARCH-LEUBA: Okay. The most 22 likely reason you have a LOCA is because you have an 23 earthquake, and you don't have power.

24 Okay. I will wait.

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155 MEMBER KIRCHNER: But let them, let them 1

do that in PRA space.

2 MEMBER DIMITRIJEVIC: Why in the PRA 3

space? You know, I just want to say you guys are now 4

discussing details that we don't even have a good big 5

picture.

6 We obviously have a difference in opinion.

7 We don't have all the calculations we need. Now, 8

where do we go from here?

9 That's the big picture.

10 MEMBER KIRCHNER: The big picture, if I 11 could summarize, Vesna, is the concern is post-ECCS 12 actuation for a variety of initiating events can lead 13 to boron dilution of the downcomer.

14 The boron -- the diluted downcomer 15 introduces the possibility of a reactivity insertion 16 event. Which could potentially lead to core damage.

17 So, the big picture is, how does one 18 prevent that from happening?

19 MEMBER DIMITRIJEVIC: Okay. So, --

20 MEMBER KIRCHNER: And demonstrate that you 21 can do it.

22 MEMBER DIMITRIJEVIC: All right. So, your 23 proposal is that they address this with the tech specs 24 or we're talking procedures.

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156 When should this happen? Now? Or how do 1

we make -- I mean, they're not going to write 2

procedures that -- they have some tech specs, you 3

know, section.

4 And we can --

5 MEMBER KIRCHNER: Earlier. We heard 6

earlier from the staff today and yesterday. They seem 7

to be in a position where they believe they can issue 8

an FSER.

9 And that the Applicant has met all the 10 requirements for the DCA. And we, in the course of 11 preparing this letter, can affirm that descent.

12 We can point out whatever deficiencies we 13 see possible. I don't think at this point we're going 14 to see any new design changes.

15 We're not likely to see any new analysis.

16 So, we have what we have. And we can then, as a 17 collegial body, come to a conclusion on this issue.

18 MEMBER DIMITRIJEVIC: But the whole, how 19 do they come to the conclusion, or all of us, how do 20 we come to a conclusion that this is not a risk 21 outlier?

22 MEMBER KIRCHNER: Well, you may convince 23 us that this is a risk outlier. And we put that in 24 the letter.

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157 MEMBER DIMITRIJEVIC: Well, -- well, the 1

cla -- you know, that's what I was sort of on there 2

yesterday. What is our -- I mean, if you write a 3

letter that this we can, you know, we disagree with 4

ACR conclusions on Chapter 19 for example, or Chapter 5

15.

6 Then where do we go from there? I mean, 7

you know, if that --

8 MEMBER KIRCHNER: We document them. And 9

the COL Applicant will likely not ignore an ACRS 10 letter that has anything that has a negative or a 11 conclusion that suggests that further work isn't 12 necessary before the COL application is accepted by 13 the Commission.

14 MEMBER DIMITRIJEVIC: But whatever has to 15 point, when they point that there is a difference of 16 opinion, there is not just difference in opinion 17 between, you know, the staff and us.

18 There is a difference of opinion among the 19 staff. So, I mean, there is so many --

20 MEMBER KIRCHNER: But Vesna, Vesna stay 21 out of that. That is something that is dealt with 22 through a formal process.

23 And that's a staff issue. That's not an 24 ACRS issue.

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158 MEMBER DIMITRIJEVIC: Well, it was 1

presented to us. So, I mean, we don't --

2 MEMBER KIRCHNER: It was. We -- that's 3

our role to hear all positions. And also ask for 4

public input.

5 MEMBER PETTI: But isn't it in fact, your 6

major point Walt, is that we've got to look at 7

prevention here. And think about that.

8 MEMBER KIRCHNER: Well, this is --

9 MEMBER PETTI: Which I think there's been 10 enough about that.

11 MEMBER KIRCHNER: I think, you know, if 12 you remember our meetings with the Applicant, I 13 stopped let's see, who was it?

14 It wasn't Paul. It was probably Matthew 15 Presson. Very early in the presentation, the first 16 time they presented after they had made design 17 changes.

18 And I -- he had, you know, I don't have 19 the view graph in front of me. He talked about 20 prevention and mitigation, I believe. And I may not 21 be quoting the view graph well.

22 But, it was clear that their design 23 changes, their first objective was prevention. And I 24 think to a large part, they succeeded.

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159 So, yeah. As Ron pointed out earlier, if 1

you're going to -- let me back up. Years and years 2

ago, I don't like to do this, but I'm going to do it.

3 Years and years ago, there was something 4

called the Clinch River Breeder Reactor. And this 5

sounds like I'm getting off topic.

6 But --

7 VICE CHAIR REMPE: Really, it was just a 8

paper reactor. There never was a reactor, right?

9 MEMBER KIRCHNER: Well, no. There was a 10 pretty solid design actually. And it was derivative 11 of FFDF, which was built and operated.

12 So, we're talking about yes, paper, on 13 paper. But fairly mature design concepts and so on 14 and so forth.

15 And what happened with CRBR among other 16 things was that there were, what should I say, event 17 paths that could lead to and challenge core integrity, 18 probably, oh bad choice in words, likely, with a 19 higher frequency then we would ever see in an LWR in 20 the existing fleet.

21 And so the NRC actually funded Los Alamos 22 to develop a safety analysis code specifically for 23 fast reactors, for liquid metal fast reactors. It was 24 called poor choice of acronyms. Don't ever do this in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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160 the future. SIMMER, S-I-M-M-E-R.

1 A tremendous amount of effort went into 2

it. But what was realized was something that Ron was 3

alluding to earlier today.

4 It was going to be a calculational warfare 5

between you know, the applicant, the regulator and the 6

public about, you know whose estimates were better.

7 Much more difficult problems I would suggest.

8 It's like being -- it's like being in 9

MELCOR space. You don't want to be in MELCOR space 10 because now the uncertainties, the difficulty of the 11 physics, the chemistry, everything gets, you know, so 12 much more complicated.

13 So, my feeling is, Dave, well, pardon the 14 ramble, we don't want to get there. I think there are 15 ways to intervene so that getting into the red box is 16 yes, it's probably worth exploring.

17 But, what's the old maxim? There's 18 something about -- something about prevention is worth 19 a lot of cure. And I forget the measurement. I don't 20 want to do it in dollars of reactivity.

21 MEMBER BALLINGER: It's a pound of 22 convention is a, of prevention is worth an ounce of 23 cure.

24 MEMBER KIRCHNER: Or whatever it was.

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161 Yeah.

1 MEMBER BALLINGER: It's something like 2

that. The corollary is, cut the head off the snake.

3 MEMBER KIRCHNER: Yes. That's it. Thank 4

you, Ron. You just don't want to be there.

5 MEMBER RICCARDELLA:

An ounce of 6

prevention is worth a pound of cure.

7 MEMBER BALLINGER: Ah, okay. I had it 8

backwards. Okay.

9 MEMBER KIRCHNER: I was tongue-tied.

10 Thank you, Pete. Mr. Chairman, I think I've done --

11 I've used too much of my platform as the subcommittee 12 chair.

13 I think where we go from here is we take 14 this. I've already talked to several members. First, 15 I want to say to all members, thank you.

16 And I want to say that please send any 17 further input you have to me and the rest of the 18 Committee. And my proposal is that myself, Member 19 March-Leuba, and Member Petti take it from here.

20 And try and provide the Committee a draft 21 next week. I don't want to pick a day next week, but 22 provide something next week, because we are on a tight 23 time schedule.

24 And our next full Committee meeting is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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162 just a short two weeks away. And this lastly, I want 1

to say once again, thank you to the Applicant.

2 And thank you to the staff. We know how 3

hard you've been working. And we appreciate your 4

presentations and your patients with us.

5 And with that, I am going to stop and turn 6

it over to you, Mr. Chairman.

7 CHAIR SUNSERI: Thanks Walt. And thanks 8

for leading that session. Looking ahead, I think we 9

still need to answer the question for the upcoming 10 full Committee week.

11 Do we need any additional presentations 12 from staff or Applicant on any topic to help us with 13 our deliberation?

14 MEMBER BLEY: Well, since I brought that 15 up earlier, I'll take a shot now. I don't see a need 16 for presentations.

17 But, I think each of us, as we go back and 18 review, this week, review the transcript. And for me, 19 especially review the Peter Yarsky paper.

20 There will be questions, and I don't think 21 open-ended discussions of questions is appropriate in 22 a letter writing session. So, I'd like to see us have 23 at least a two hour session which would allow us to 24 raise questions and discuss them in detail with the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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163 staff and with NuScale if they participate.

1 And I'd like to hear from others too on 2

that, because, you know, that might not be enough 3

done.

4 MEMBER KIRCHNER: Actually Dennis, maybe 5

four hours on the first day of our meeting for that 6

purpose.

7 MEMBER BLEY: And if we finish early, 8

that's great. But, I just can't see us not having 9

things we really want to pursue with the staff and the 10 Applicant.

11 MEMBER MARCH-LEUBA: Dennis, can we make 12 a commitment as members to think through everything we 13 still need to know, writing down, and send the 14 questions in advance to the staff so that they can 15 prepare a presentation to respond to our specific 16 questions.

17 Instead of go fill me up four hours of 18 entertainment, no. I still need an answer to this 19 particular question. Can you please prepare for it.

20 MEMBER KIRCHNER: Yeah. So, we don't --

21 MEMBER BLEY: I think the Board makes 22 that.

23 MEMBER KIRCHNER: Yeah, we don't send it 24 to the staff. We'll send it to Mike Snodderly.

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164 MEMBER MARCH-LEUBA: Sure.

1 MEMBER KIRCHNER: And he'll collate and 2

collect any input.

3 MEMBER MARCH-LEUBA: But do we have a buy 4

in for all the members that that's what we're going to 5

do?

6 MEMBER BLEY: Well, sure. With the 7

proviso that we may still be working on this the 8

weekend before, and then we have a full week.

9 So there -- we can't be assured that 10 everybody will get everything written down.

11 MEMBER MARCH-LEUBA: You can always ask 12 questions on the spot. But, any important question, 13 it would be really nice if we write it out in advance, 14 send it through Mike to the staff. And say hey, I 15 still have doubts on this. Prepare an answer.

16 That would be fantastic that. That would 17 be good.

18 MEMBER DIMITRIJEVIC: Mike, when did you 19 say we were going to get out into documentation?

20 MR. SNODDERLY: I'm sorry, Vesna. Could 21 you please repeat that? When are we going to what?

22 MEMBER DIMITRIJEVIC: You said that we 23 were going to get out the documentation late --

24 MEMBER KIRCHNER: July 17.

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165 MR. SNODDERLY: The audit summary July 17, 1

next Friday.

2 MEMBER KIRCHNER: July 17.

3 MEMBER DIMITRIJEVIC: That will be just a 4

couple of days before the meeting.

5 MR. SNODDERLY: Yes. But as I said, I 6

don't think you're going to -- well, I just -- yes.

7 That's what they've proposed.

8 MEMBER DIMITRIJEVIC: But somebody said 9

there is a four hundred or five hundred pages in that 10 document.

11 MR. SNODDERLY: No. That's -- if someone 12 from the staff could give us an estimate. But, I 13 think that -- I don't know where -- where did you hear 14 that, Vesna?

15 MEMBER DIMITRIJEVIC: Well, it was in our 16 discussion somebody say on the -- I think maybe Dennis 17 estimate that. I'm not sure. Somebody said it and 18 we're not that far.

19 (Simultaneous speaking) 20 MEMBER KIRCHNER: I don't think there was 21 the estimate of the page length to anyone. Let's 22 just, let's just do that.

23 MR. SNODDERLY: Yeah. Maybe they reviewed 24 that many pages. They probably reviewed that many.

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166 But, I don't think that that report is anywhere near 1

that.

2 Again, it's a summary. But, I'll follow 3

up on that. But, one thing I would like from the 4

Chairman, so what was the deadline for providing 5

questions for me to then pass onto the staff?

6 Because remember, they need time to 7

prepare.

8 MEMBER KIRCHNER: That's right. Let's 9

see, I have not a calendar in front of me. But I know 10 that we have a two week window.

11 So, I would ask my colleagues, could you 12 do it by the end of next week? The close of business 13 next Friday?

14 Because -- or even Thursday would be 15 better. Thursday would be better, then Mike and I 16 perhaps on Friday could go over them and consolidate 17 the things that might overlap.

18 And then for that -- to the staff.

19 MEMBER MARCH-LEUBA: Walt, you keep saying 20 two weeks. It's one week. Okay, we have one free 21 week to work. The next week we'll be in meetings.

22 MEMBER KIRCHNER: Oh, I'm sorry. My 23 mistake. You're right. Okay, hold on. I'll get a 24 calendar.

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167 MEMBER DIMITRIJEVIC: Walt, this is why I 1

was bringing this out. Is because we can even have 2

more questions after we look at this outed document.

3 MEMBER KIRCHNER: Well, here's the 4

problem. The problem is now, with the calendar in 5

front of me, we've been told that we'll get the audit 6

document on July 17.

7 That's a week from today. And then we 8

reconvene the following week. Thank you, Jose, for 9

pointing out my oversight.

10 If you have questions, I -- probably we 11 would have to say Wednesday. And that does not give 12 staff a lot of time.

13 MEMBER BLEY: Anything after that we just 14 bring up in the meeting.

15 MEMBER KIRCHNER: Yeah. Just bring up in 16 the meeting. I mean, I'm assuming now we're talking 17 about a really, you know, substantive issue, not a --

18 not just clar -- issues of clarification.

19 Because I think we can bring those up in 20 the meeting.

21 MR. SNODDERLY: I would request Wednesday 22 at lunchtime. That way then Walt, you and I have --

23 MEMBER KIRCHNER: Okay. Okay, Mike.

24 Yeah.

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168 MR. SNODDERLY: Yes. Can we get it out by 1

Wednesday by close of business to the staff.

2 MEMBER KIRCHNER: Okay. Good point. And 3

that's lunchtime is 12:00 Eastern daylight time.

4 MR. SNODDERLY: So, I just heard from the 5

staff. They estimate the audit report will be about 6

20 pages.

7 So, as I said before, I really think the 8

Committee should stay focused on resolving from this, 9

these interactions between the staff and NuScale.

10 Which was the May 20 submittal, the June 19 submittal, 11 and the May 28 8930 supplement.

12 So, that's the bulk of the documentation.

13 And of course the Yarsky white paper.

14 MEMBER KIRCHNER:

Yes.

Another 15 housekeeping matter here. Alexandra, would you send 16 what you have on the screen to the members and staff 17 only? ACRS staff only.

18 And I just remind the public, since you 19 have the opportunity to participate, these are not 20 positions of the Committee. These are just topics 21 that we will consider in our letter report.

22 The Committee can only speak through its 23 final letter report. So, we have not made any effort 24 here to edit these in any way to reflect a position of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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169 the Committee.

1 Mr. Chairman?

2 CHAIR SUNSERI: Thank you, Walt. So, any 3

other final input from the Committee?

4 MEMBER BLEY: Yes. This Dennis. And I 5

apologize for missing Anna Bradford's opening remarks.

6 I have searched through Part 52, and to 7

some extent searched through the SRM guidance -- or 8

the SRP guidance on reviewing applications.

9 And I haven't found the guidance or 10 regulation that says, don't consider anything after 11 the initial point of stability.

12 If anybody can point me to something like 13 that, I'd like to, you know, be familiar with it 14 before our next meeting. I'm going to keep looking.

15 CHAIR SUNSERI: Can you state that again?

16 You were a little muffled on my microphone. What are 17 you looking for again?

18 MEMBER BLEY: I am looking for regulation 19 or the guidance that tells the staff anything dealing 20 with recovery, no matter how unstable the position, is 21 not an issue for the design cert.

22 I can't find it. I have -- I shouldn't 23 say that. I have not yet found it. I'm still 24 looking.

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170 CHAIR SUNSERI: Okay. I understand.

1 MEMBER MARCH-LEUBA: Yeah. I support 2

Dennis' statement. Is it possible to add an 3

additional paragraph to Sandra's letter?

4 Because a couple of members mentioned that 5

using source range flex monitors to recover from a 6

critical event, is certainly not recommended.

7 (Simultaneous speaking) 8 MEMBER KIRCHNER: If we could capture 9

Dennis' thoughts, because that was the part that I had 10 missed on this morning when I was taking notes.

11 VICE CHAIR REMPE: So, actually, that's 12 already captured. If you'll go to the lower numbers.

13 MEMBER KIRCHNER: Is it? Okay.

14 VICE CHAIR REMPE: And also, the thing 15 about the instrumentation. Please show lower numbers.

16 I'd defy it, but flip on it. Lower numbers, please.

17 MEMBER MARCH-LEUBA: We don't have to talk 18 19 VICE CHAIR REMPE: Okay, there. Guidance 20 is number nine. And that's the thought. And then the 21 exist -- it should be with unvalidated analysis code 22 and existing plan instrumentation.

23 And that's what I'm trying to get to here.

24 Okay, Jose?

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171 MEMBER MARCH-LEUBA: Sorry, what was --

1 what was the line number?

2 VICE CHAIR REMPE: On number three --

3 four.

4 MEMBER MARCH-LEUBA: I couldn't see.

5 VICE CHAIR REMPE: Look at line four. It 6

says existing plant instrumentation.

7 MEMBER MARCH-LEUBA: But, I think we can 8

be, you know, a little stronger than this. Saying 9

that it has been proposed to use a criticality alarm 10 to control boron addition to the core. And we don't 11 think that's wise.

12 VICE CHAIR REMPE: We don't need to write 13 it out.

But just put under existing plan 14 instrumentation, put criticality alarm.

15 Right, Jose? We're just trying to put a 16 note to jog your memory as you write this thing, 17 right?

18 MEMBER MARCH-LEUBA: Right. Yeah. I just 19 think that using a criticality alarm to control your 20 boron presentation, it is not advisable.

21 MEMBER KIRCHNER: We discussed that.

22 VICE CHAIR REMPE: Right. And then on the 23 documents and regulations they need to be modified.

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172 statement saying that they met the existing 1

regulation. It clarified, I mean, she even said, you 2

guys can think of a way to do this.

3 I mean, with her point about the fact that 4

you can't do a pull out because of the fact that this 5

is so linked integral to the reactor. But, is Anna 6

still on the line?

7 I can't see the whole group.

8 (Simultaneous speaking) 9 MEMBER KIRCHNER: No, Joy. Let's not 10 debate -- let's not debate our letter writing with the 11 staff.

12 VICE CHAIR REMPE: No. I'm not trying to 13 do that. I want her clarification. Dennis asked a 14 question.

15 If she's here, she knows, I think, the 16 answer to Dennis' question, Walt. Right?

17 MEMBER KIRCHNER: All right.

18 VICE CHAIR REMPE: And I -- if Anna is on 19 the line, then she is --

20 MEMBER MARCH-LEUBA: Why don't we wait, 21 Joy. Sandra needs to know that what she did is okay.

22 And I think it's sufficient.

23 She put criticality along with line four.

24 And that reminds us that what we need. So, that --

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173 for Sandra, you don't need to do anything for my 1

account.

2 VICE CHAIR REMPE: Okay. If you're going 3

to -- I thought you were taking care of your stuff.

4 MEMBER KIRCHNER: So, let me just be 5

clear, I wasn't talking about --

6 VICE CHAIR REMPE: And after moving the --

7 thing, then we're there. But, is Anna still on the 8

line?

9 MEMBER KIRCHNER: No, Joy. Wait a minute.

10 Wait a minute. Let's observe the process. What 11 precisely is the question that you want to pose?

12 VICE CHAIR REMPE: Dennis question that he 13 asked. Is there some guidance that led the staff to 14 believe you don't -- could not ask for recovery.

15 MEMBER KIRCHNER: Let's do the following.

16 Let's do the following, let's not put the staff in a 17 position of having to respond on the spot.

18 Let's pass that request through Mike 19 Snodderly.

20 VICE CHAIR REMPE: It would be nice if we 21 could hear a little sooner then next week. But, I 22 think -- yes, if you could point to a section, you 23 know, she had that.

24 But we were told that earlier today. And 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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174 I wanted to ask at the time. But I didn't it in.

1 MEMBER KIRCHNER: I defer to you, Mr.

2 Chairman.

3 CHAIR SUNSERI: Yes. I agree with letting 4

Snodderly ask the question and let them reflect on it.

5 Because we're talking two different things.

6 They're talking procedures. And Dennis 7

framed it a little differently then procedures. So, 8

let's not put them in a spot by giving a reaction 9

without reflecting on the request.

10 VICE CHAIR REMPE: Okay.

11 CHAIR SUNSERI: And let me just be clear 12 on what I was saying a little earlier. Because people 13 like to take what I say and then change it.

14 But, I'm not talking about using a 15 criticality alarm to approach critical. And I know 16 the accident situation is different and there needs to 17 be some compensation.

18 I get that. I understand. I'm a nuclear 19 engineer. I'm just suggesting that, I've been on 20 several power reactors where we have diluted the 21 criticality using source range instrumentation, 22 plotting count rate, and in doing a very controlled 23 approach to criticality.

24 That's my simple comment. You could 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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175 probably turn that around, if you wanted to. And 1

think about an approach to avoiding criticality using 2

those kind of instruments and that approach.

3 And I will also say, there's not that much 4

momentum, fluid momentum. When you turn off that CFDS 5

system, it's going to stop. It's only 100 gallons per 6

minute.

7 MEMBER MARCH-LEUBA: All I want Matt, is 8

a calculation and an estimate from a risk analysis and 9

HRA specialist of how long it would take for the 10 operator to recognize the problem. Which will be not 11 much, because there's a criticality alarm.

12 And then push the button to stop it. And 13 what is the probability that he will push the wrong 14 button when it's at --

15 CHAIR SUNSERI: I'm not arguing all that.

16 I mean, that's the probability and all that stuff. I 17 mean, what -- so, what's the probability of success is 18 not the question.

19 The question is, is there a success path?

20 Can we contemplate one that would be successful?

21 MEMBER MARCH-LEUBA: Well --

22 CHAIR SUNSERI:

I'm just saying 23 everybody's imposing their extreme positions. I'm in, 24 you know, I get the right to impose mine as well, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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176 don't I?

1 MEMBER MARCH-LEUBA: Yes, you are. Yes, 2

you are, Matt. And as an engineer, as a guy that has 3

worked on a plant, you are fully right.

4 But, if risk analysis people need to 5

consider what kind of probability field that something 6

will go wrong. And put that on their PRA.

7 And tell me that it probably something 8

will go wrong is less than 10 to the minus 11.

9 Because if it's more then 10 to minus 11, which is a 10 ridiculously low number, it becomes the critical path 11 for this one.

12 CHAIR SUNSERI: Yes. So, I mean, I don't 13 want to --

14 MEMBER DIMITRIJEVIC: It's a nine. It's 15 a nine. You're repeating the minus 11. But there's 16 nothing minus 11. I mean, therefore we have to be 17 even below the 10 to minus nine not to be the, you 18 know, the significant consequences.

19 So, I wouldn't -- the minus 11, it's never 20 mind.

21 MEMBER MARCH-LEUBA: Nine and 11 among 22 friends. There is a 10 to the minus in front of it is 23 the same thing.

24 CHAIR SUNSERI: So, okay. Any other 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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177 comments and input? This is good.

1 (No response) 2 CHAIR SUNSERI: Since this has been a 3

little bit of a modified session then our normal 4

report preparation session, and since this is a public 5

line, I would like to kind of close this session with 6

an opportunity for the public listening in to make any 7

statements or comments.

8 So, Thomas, if we could open the public 9

line, please.

10 THOMAS: The public line is open for 11 comment.

12 CHAIR SUNSERI: Thank you. So, any 13 members of the public that are listening in, if you 14 care to make a statement or a comment, now is the 15 opportunity to state your name and provide your 16 comment, please.

17 MS. FIELDS: Yes. This is Sarah Fields.

18 I didn't expect there's an opportunity to make a 19 comment.

20 I think you are in a very serious and 21 critical situation. I've been following this process 22 with the NRC and with the ACRS for quite a while.

23 I have little or no technical background.

24 But I have had long experience with the Nuclear 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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178 Regulatory Commission.

1 I was in a town with a one billion dollar 2

3 (Simultaneous speaking) 4 CHAIR SUNSERI: Could you hold on please?

5 Would everybody that's not speaking, mute their 6

microphone?

7 (Simultaneous speaking) 8 MS. FIELDS: Okay. I'm sorry.

9 CHAIR SUNSERI: No, no. Hold on please.

10 Somebody has got their microphone open and disrupting 11 the flow.

12 Could we please mute our microphones and 13 let the public have their chance to talk. Sarah, 14 please go on.

15 MS. FIELDS: I live in a community with a 16 one billion dollar uranium tailings removal project.

17 I live in an area where there are a number of 18 abandoned uranium mines, permitted mines.

19 And the only operating convention is the 20 uranium mill. I have seen many errors by the Nuclear 21 Regulatory Commission over the years.

22 Most of you have worked in the industry.

23 But probably none of you have lived within 50 miles of 24 a proposed nuclear reactor and attended the emergency 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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179 planning meetings. Or you probably not lived within 1

10 miles of a reactor that was under construction.

2 So, I -- because I've experienced many 3

things and been involved in many NRC proceedings and 4

meetings, and what

not, I

have a

different 5

perspective.

6 And I really hope that you will lay out to 7

the NRC staff and to NuScale, and for the benefit of 8

the public, all of your concerns about this design.

9 I am sure if there is any problem in the 10 future that people will look back and say, well, you 11 know, how did this happen?

12 How did we miss this? What did NuScale 13 say? What did the NRC say? What did the ACRS say?

14 So, it's important that you fully express 15 all your concerns about this design. I know, you 16 don't address the PR aspect of this whole thing.

17 You don't make a decision about whether 18 this NuScale design is a carbon free power project.

19 Which, if course, is ridiculous industry in Department 20 of Energy public installations.

21 So, I see many different views from many 22 different aspects. I see the local concern about the 23 cost of this.

24 I see the NuScale and the industry trying 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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180 to save money and reduce the cost by limiting the 1

emergency planning zone. By reducing the number of 2

operators to one in the control room.

3 When you're talking about control room 4

operator action, that maybe just one operator and two 5

senior operators. That's what NuScale would like to 6

have.

7 So, there are a

lot of different 8

perspectives that you don't hear about, that you don't 9

know about. But, you need to completely consider and 10 document all the issues. Thank you.

11 CHAIR SUNSERI: Thank you for those 12 remarks. Any other members of the public care to make 13 a comment?

14 MR. DAVIS: This is Ed Davis with the 15 Pegasus Group. I've just got a very simple question.

16 Is the NRC White Paper, 30 page White 17 Paper going to be made available? And if so, where 18 would we find it?

19 CHAIR SUNSERI: I'm going to ask you to 20 contact our Federal Agent, Mike Snodderly for a 21 response to the question.

22 Mr. Snodderly would you make a statement?

23 MR. SNODDERLY: Yes. So, Dr. Yarsky's 24 paper does have a -- does have an ML number. But I 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.

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181 don't know if they have a -- it is a proprietary 1

report.

2 I don't know if they're going to is -- I 3

would imagine they're going to issue a redacted 4

version.

5 Is there someone from the staff that can 6

verify what I'm saying is correct?

7 MS. BRADFORD: This is Anna Bradford from 8

the Office of Nuclear Reactor Relation. Yes. Our 9

plan was to, as you said, Mike, it's a prop version 10 that you have.

11 But we do plan to make a non proprietary 12 version publically available.

13 MR. SNODDERLY: So Ed, if you contact --

14 Mr. Ferguson, if you -- yeah, -- my email is 15 Michael.Snodderly@NRC.gov. And I can get you that ML 16 number when the public version is available.

17 But it doesn't exist at this time.

18 MS. DAVIS: Well, thank you very much.

19 Thank you.

20 MR. SNODDERLY: You're welcome.

21 CHAIR SUNSERI: Okay. Any other members 22 of the public care to make a comment?

23 (No response) 24 CHAIR SUNSERI: All right. Thank you.

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182 Thomas, please close the public line.

1 THOMAS: The public line is closed.

2 CHAIR SUNSERI: Members, any additional 3

business to cover before we close this meeting?

4 (No response) 5 CHAIR SUNSERI: Okay. Well, I just want 6

to extend the appreciation of the ACRS to the NRC 7

staff, and the Applicant who supported us this 8

weekend.

And everybody's engaged and active 9

participation.

10 So, I thank you all. And at this point, 11 we are adjourned. Thank you.

12 (Whereupon, the above-entitled matter went 13 off the record at 4:35 p.m.)

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DHRS ECCS/SBLOCA Setpoint changes and Riser Holes Two analytic bounding methods OK Before ECCS Actuation After Actuation DBA Ruleset:

Conservative March 2020 SC results OK Beyond DBA (e.g. ATWS):

Best Estimate Multidimensional Analysis Core mixing or oscillatory Flow How much and how fast downcomer water can enter Reactivity Effects:

kinetic issues; doppler and void coefficient OK

?

Recovery Actions, Path or Strategy?