ML25195A127
| ML25195A127 | |
| Person / Time | |
|---|---|
| Issue date: | 06/04/2025 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| NRC-0363 | |
| Download: ML25195A127 (1) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Docket Number:
(n/a)
Location:
Rockville, Maryland Date:
Monday, June 4, 2025 Work Order No.:
NRC-0363 Pages 1-67 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1716 14th Street, N.W.
Washington, D.C. 20009 (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 726TH MEETING 4
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
(ACRS) 6
+ + + + +
7 MONDAY 8
JUNE 4, 2025 9
+ + + + +
10 The Advisory Committee met at the Nuclear 11 Regulatory Commission, 11545 Rockville
- Pike, 12 Rockville, Maryland, and via Videoconference, at 8:30 13 a.m., Walt Kirchner, Chair, presiding.
14 COMMITTEE MEMBERS:
15 WALTER L. KIRCHNER, Chair 16 GREGORY H. HALNON, Vice Chair 17 DAVID A. PETTI, Member-at-Large 18 VICKI M. BIER 19 VESNA B. DIMITRIJEVIC 20 CRAIG D. HARRINGTON 21 ROBERT P. MARTIN 22 SCOTT P. PALMTAG 23 THOMAS E. ROBERTS 24 MATTHEW W. SUNSERI 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
2 ACRS CONSULTANTS:
1 DENNIS BLEY 2
4 DESIGNATED FEDERAL OFFICIAL:
7 ALSO PRESENT:
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
3 P-R-O-C-E-E-D-I-N-G-S 1
(8:30 a.m.)
2 CHAIR KIRCHNER: This is the first day of 3
the 726th meeting of the Advisory Committee on Reactor 4
Safeguards, ACRS. I am Walt Kirchner, Chairman of the 5
ACRS. ACRS members in attendance in person are Ron 6
Ballinger, Vicki Bier, Greg Halnon, Craig Harrington, 7
Robert Martin, Scott Palmtag, Dave Petti, Thomas 8
Roberts, and Matt Sunseri. ACRS Member Vesna 9
Dimitrijevic is participating virtually via Teams.
10 This morning we also are joined by our 11 consultants virtually, Dennis Bley and Steven Schultz.
12 If I
have missed
- anyone, either members or 13 consultants, please speak up now.
14 Michael Snodderly of the ACRS staff is the 15 Designated Federal Officer for this morning's full 16 committee meeting. No member conflicts of interest 17 were identified, and I note that we have a quorum.
18 The ACRS was established by statue, and is 19 governed by the Federal Advisory Committee Act or 20 FACA. The NRC implements FACA in accordance with our 21 regulations.
Per these regulations and the 22 Committee's bylaws, the ACRS speaks only through its 23 published letter repots. All member comments 24 therefore should be regarded as only the individual 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
4 opinion of that member, and not a Committee position.
1 All relevant information related to ACRS 2
activities such as letters, rules for meeting 3
participation, and transcripts are located on the NRC 4
public website, and can be readily found by typing 5
about us ACRS in the search field on NRC's home page.
6 The ACRS, consistent with the Agency's value of public 7
transparency and regulation of nuclear facilities, 8
provides opportunity for public input and comment 9
during our proceedings.
10 For this full committee meeting, we have 11 received no written statements, however written 12 statements may still be forwarded to today's 13 designated federal officer. And we, as always, have 14 set aside meeting at the end of this meeting for 15 public comment. A transcript of the meeting is being 16 kept, and will be posted on our website.
17 When addressing the Committee, the 18 participants should first identify themselves, and 19 speak with sufficient clarity and volume so that they 20 may be readily heard. If you are not speaking, please 21 mute your computer on teams. If you are participating 22 by phone, press star six to mute your phone, and star 23 five to raise your hand on Teams.
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5 available for use during the meeting. For everyone in 1
the room, please put all of your electronic devices in 2
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speakers.
In
- addition, please keep sidebar 4
discussions in the room to a minimum, since the 5
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6 We will not have presenters, but for 7
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microphone to be heard online. Finally, if you have 10 any feedback for the ACRS about today's meeting, we 11 encourage you to fill out the public meeting feedback 12 form on the NRC's website.
13 During today's meeting the Committee will 14 consider topics from our recent subcommittee meeting, 15 and that is draft Interim Staff Guidance on the 16 content of risk assessment severe accident information 17 in light-water power reactor construction permit 18 applications. And also a summary from our PRA and 19 Advanced Reactor Subcommittee meeting, both of those 20 were held on May 21st.
21 And unless there are comments or other 22 items from members, I am going to turn the microphone 23 to Vicki Bier, subcommittee chair of our Regulatory 24 Rulemaking, Policies, and Practices Subcommittee.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
6 MEMBER BIER: Thank you, Walt. I guess we 1
will start with the CP PRA guidance, and since it is 2
PRA related, I certainly think it was appropriate for 3
us to have a briefing from the staff on this. But it 4
seems like there is not anything there that rises to 5
the level that would justify a letter. For one thing, 6
if anything, our comments were mostly that the 7
guidance was really held unprescriptive, so that has 8
cost implications potentially, but not safety 9
implications.
10 And a lot of the PRA use at the CP stage 11 is kind of discretionary, people have the option not 12 to do PRA for certain parts of their safety case, or 13 whatever. So, if some parts seem overly burdensome, 14 licensees should be able to just kind of work around 15 that, and use the parts they want, and not the parts 16 they don't want.
17 So, we have a short, I guess a little more 18 than a page, summary report just for file. Do you 19 have that ready to pull up Sandra? Okay, I think 20 everybody should have a copy at their desk also. I 21 will go ahead and read it, and maybe chime in with 22 comments here and there, but mostly just read through, 23 and then we can discuss if there is any changes before 24 approving and filing.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
7 So, our Regulatory Rulemaking, Policies, 1
and Practices Subcommittee met with NRC staff and a 2
representative of the Nuclear Energy Institute, I 3
guess somebody will have to finalize the acronyms, put 4
the little NEI there, and all that kind of stuff, on 5
May 21st, 2025, to discuss draft final Interim Staff 6
Guidance, content of risk assessment -- I won't read 7
the whole title.
8 The NRC staff developed this ISG to 9
further clarify the scope and depth of their review of 10 the content of risk analysis and severe accident 11 information in a construction permit application for 12 a light-water power reactor. The NRC anticipates the 13 submission of power reactor CP applications based on 14 preapplication engagement initiated by several 15 prospective applicants and vendors.
16 The review of these applications falls 17 within the two step licensing process under Part 50, 18 blah, blah, blah, and involves the issuance of a CP 19 before an operating license. Part 50 does not require 20 development of a probabilistic risk assessment for a 21 CP application, as reiterated by the Commission in its 22 Staff Requirements Memorandum SECY-220052.
23 This ISG provides guidance in cases where 24 a CP applicant uses risk assessment and severe 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
8 accident information to support its application. A 1
couple of observations, in general some of the 2
expectations in the ISG seem potentially excessive to 3
the stage of design detail that would typically be 4
available at the time of the CP application.
5 E.g., seismic risk analysis, for example, 6
if you don't know where the pipes are going to go, it 7
is pretty hard to do a thorough seismic analysis.
8 However, it is possible that some applicants might 9
want to submit such information, so I didn't see a 10 problem leaving it in the ISG of how they would review 11 it if somebody did submit this. It is not requiring 12 that they do submit it.
13 Second observation, Jon Facemire of NEI 14 suggested that, I think it's table two in the report, 15 titled additional elements for CP application, should 16 include a
column allowing for traditional 17 deterministic approaches for some hazards, since 18 applicants may conceivably want to mix and match.
19 E.g., using deterministic approaches for 20 some hazards, and PRA or alternative risk evaluations 21 for others. This seems reasonable. Member Bier and 22 the Subcommittee recommend that the Committee have no 23 objection to the staff issuing the draft final ISG, 24 and recommend that we not write a letter on the topic.
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9 In particular, no crucial safety issues are presented 1
by the CP ISG, since applicants would still be 2
expected to submit a complete PRA at the time of the 3
operating license application.
4 I guess that should be in the final 5
version, and any safety problems could presumably be 6
identified at that time. Therefore any potential 7
issues with the CP ISG, whether excessive expectations 8
for the PRA for the possibility of receiving CP 9
approval, but then discovering costly problems at the 10 OL level pose only business risks for applicants, not 11 safety risks, and are hence not an issue for the 12 Committee.
13 And so, I guess that is the version of the 14 report that we now have. And if there is any 15 discussion, suggested changes, cleanup in wording, et 16 cetera, I am happy to entertain them.
17 MEMBER PETTI: The concern that I have is 18 sort of like what's there on line 22, the 19 excessiveness. What I worry about is advanced 20 reactors going under Part 54 CP, and where the line is 21 there versus where the line is for LWRs, and making 22 sure that they're not so disparate. Just because we 23 know a lot more about LWRs, I mean it almost looks 24 like the ISG is a forcing function, is an expectation 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
10 to really mature the design at the CP stage. And so, 1
the inconsistent philosophy I think is the concern.
2 MEMBER BIER: So, the document that we're 3
reviewing says it's for light-water power reactors, 4
but I certainly would not object to adding a sentence 5
after line 24 saying consistency between light-water 6
and advanced reactor designs should be considered or 7
something like that, I don't know how to frame it.
8 And I think these subcommittee reports are not 9
supposed to say should.
10 So, maybe somebody can word engineer how 11 to discuss that. I guess we could say the Committee 12 also discussed the issue of consistency between --
13 MEMBER PETTI: Yeah, that would be --
14 CHAIR KIRCHNER: You can just add there.
15 MR. SUNSERI: Just make a factual 16 statement, consistency between the two things would be 17 a focus of discussion in future implications.
18 MEMBER PETTI: You could say something 19 also like the Committee considers it important to 20 maintain consistency.
21 MEMBER BIER: Yeah.
22 MEMBER PETTI: Or however you want to say 23 it.
24 MEMBER BIER: We can do again as a factual 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
11 statement.
1 CHAIR KIRCHNER: Dave, on your point, it 2
seemed to me when I read the ISG, it had everything 3
you would want in a full blown PRA level one and two.
4 So, at a CP stage, it just doesn't -- it's complete, 5
the ISG so to speak, but is that a realistic 6
expectation?
7 MEMBER BIER: I mean, to me the issue that 8
would have been a safety concern was if somebody could 9
come in with their CP PRA at the OL stage, and say we 10 haven't changed any fundamental issues of the design, 11 so therefore this still applies. And staff clearly 12 said no, you couldn't use the CP level PRA to satisfy 13 the OL requirement, you would be expected to show a 14 lot more detail of the OL stage.
15 So that is the one that would have 16 bothered me from a safety point of view, but I 17 certainly think we can add a sentence about 18 consistency between light-water and advanced reactor 19 designs. Somebody want to volunteer a version, or 20 should I just?
21 MR. SUNSERI: Just one more thought before 22 we divert from that, so just thinking this way down 23 the road, would anybody over interpret what we are 24 saying, and try to force the two to come together?
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12 The advanced need to have their own latitude to do 1
their thing because they're different, right? I would 2
hate to have something to imply we want them to be 3
more closer together than to utilize the flexibility 4
that the advanced adds.
5 MEMBER PETTI: Yeah, I don't want to have 6
the advanced having to be pulled up to this level, it 7
seems like there should be some flexibility for the 8
LWRs to not have at the CP stage, as much detail. And 9
this looked like, to me when I first saw this, it 10 looked like a forcing function. Because yeah, it's an 11 ISG, but the designers are going to look at this 12 stuff, and then that's the expectation, so you are 13 forcing me to have more detail than maybe I want to at 14 that stage, that was the concern I had.
15 MEMBER ROBERTS: So, maybe it's important 16 to qualify the statement by saying Committee feels 17 it's important that the light-waters maintain the same 18 latitude of flexibility as advanced.
19 MEMBER BIER: Nice.
20 MEMBER PETTI: Yes, that would be a good 21 way to put it.
22 MR. SUNSERI: Yeah, and NEI made the point 23 that the advanced reactor reg guides need an upper 24 bounds on the amount of detail versus light-water 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
13 reactors, because they're not basing their design on 1
a PRA, whereas the light-waters are, and you need to 2
be careful with tying the two, and we can repeat the 3
point that it's an upper bound on the amount of 4
detail.
5 MEMBER BIER: So, Matt, do you want to 6
drive, or should I try and take it --
7 MR. SUNSERI: Well, you're better at 8
wording things, you've got the idea though.
9 MEMBER BIER: Okay. So, I guess at the 10 end of line 24 we can say something like in addition, 11 the Committee observes that PRA for advanced reactors 12 at the CP stage might be much less detailed than is 13 indicated in this ISG. Your line numbers are 14 different --
15 MEMBER PETTI: For light-water reactors.
16 MEMBER BIER: Yeah, that's fine. Sandra, 17 your line numbers are different than my line numbers, 18 so it should actually go down at like line 29, that 19 sentence. Can we say we hope that light-water reactor 20 applicants --
21 MEMBER PETTI: Are afforded the same 22 flexibility in terms of level of detail that is given 23 by -- given to advanced reactor applicants in -- yeah.
24 MEMBER BIER: That are given to --
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14 MEMBER PETTI: To advanced reactors.
1 MEMBER BIER: Do we want to say reactor 2
applicants?
3 MEMBER PETTI: Yeah.
4 MEMBER BIER: At the CP stage, yes.
5 Advanced reactor applicants.
6 MEMBER PETTI: That's in NEI 18-4.
7 CHAIR KIRCHNER: Perhaps rather than 8
hoping --
9 MEMBER ROBERTS: It's actually in a reg 10 guide, what is it, 1.253, or 247, one of those, it 11 talks about the scope of the PRA for a CP.
12 MEMBER PETTI: For advanced reactors.
13 MEMBER ROBERTS: For advanced reactors.
14 And that's the one that the NEI folks commented, too, 15 that it looks like it could in some ways be 16 advantageous, or at least it's high in the ISG, and 17 they felt that would be an upper bound.
18 (Simultaneous speaking.)
19 MEMBER PETTI: That's the endorsement --
20 the Reg Guides are the endorsement of the non-LWR PRA 21 standards?
22 MEMBER ROBERTS: It's actually the 23 endorsement of ARCAP/TCAP. There was an appendix in 24 that reg guide on the scope of CP.
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15 MEMBER PETTI: If we could just get that 1
2 CHAIR KIRCHNER: If we can get the right 3
reg guide up here? Just, Sandra, while we are waiting 4
to get a reg guide for you, instead of hoping, can we 5
change on line 28, we expect?
6 MEMBER BIER: Yeah, that's good.
7 CHAIR KIRCHNER: And then afforded on line 8
29?
9 MEMBER BIER: Two other minor fixes while 10 waiting for the reg guide. On 29 should say, reactor 11 applicants, not reactors. The beginning bulleting, up 12 from there, the previous line. Yeah, reactor 13 applicants. And at the beginning of line 30 should be 14 is, not are. Actually, I guess you could just delete 15 that is, the same flexibility isn't.
16 Yeah, just -- no, leave the given to, just 17 delete that is, sorry. Now, do we have the reg guide?
18 MEMBER ROBERTS: Yeah, the reg guide, it's 19 Appendix A to Reg Guide 1.253. The acceptability of 20 a PRA that supports a non-light-water reactor 21 construction permit application based on licensing 22 modernization project methodology.
23 MEMBER BIER: So, do you want to put that 24 just in parents at the end of the sentence, or do we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
16 need to work it in somehow? Sorry, do you want to put 1
that in parents, or?
2 MEMBER ROBERTS: Yeah, can we make that 3
bigger?
4 MEMBER BIER: Yeah, we really only need to 5
see that paragraph on 24 right now.
6 MEMBER ROBERTS:
- Yeah, I
think a
7 parenthetical at the end of that sentence on line 30, 8
e.g., per Appendix A of Reg Guide 1.253. In 9
Regulatory Guide 1.253, I'm sure there we'll have the 10 title.
11 MEMBER BIER: Yeah, that's fine. Thank 12 you very much Tom, and whoever else helped.
13 MEMBER PALMTAG: Instead of e.g. do you 14 want to say consistent with? So, instead of e.g., say 15 consistent with, take out per.
16 MEMBER BIER: And I don't know the 17 grammar, but I think it maybe should say will be 18 afforded instead of are afforded. Agree, Walt, or?
19 Okay. So, that is line 29, replace are by will be.
20 Any other comments on this paragraph?
21 MEMBER HARRINGTON: In the prior sentence 22 on line 28, in addition, the Committee observes that 23 PRA for advanced reactors at the CP stage might be 24 less detailed as conveyed in this ISG, or something --
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17 MEMBER BIER: Than in this ISG. Yeah, 1
after detailed, put the word than. Do we need 2
conveyed, or something else? I think it's probably 3
okay now, thanks for catching that, Craig. Anything 4
else?
5 MEMBER ROBERTS: Discussion for the next 6
paragraph.
7 MEMBER BIER: Good, let's put 33 -- yeah.
8 MEMBER ROBERTS: It used to be -- where 9
did it end up? Keep going. The phrase since 10 applicants would still be expected to submit, commit 11 a complete PRA at the time of operating license, you 12 explain that? There it is. I think I would add if 13 required parenthetically after that phrase. Because 14 right now there is no requirements that I'm aware of 15 to have a complete PRA at the time of operating 16 license.
17 That is part of the 10 CFR 50.52 18 rulemaking merging, and that is still in the 19 preliminary rulemaking stage, there is no requirement.
20 So, I think the phrase is okay as long as there is a 21 parenthetical if required. Because if there were to 22 be a PRA at the time of the operating license, it 23 would be a complete PRA for all the standards.
24 MEMBER BIER: Okay. So, right -- no, I 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
18 think the parents go after --
1 MEMBER ROBERTS: Yeah, go after license 2
application.
3 MEMBER BIER:
On the line after 4
application, yeah. There you go.
5 CHAIR KIRCHNER:
Was it with the 6
application raised, or was it by fuel loading? I 7
can't remember, it's still in flux, right?
8 MEMBER ROBERTS: It's still proposed 9
rulemaking, can't predict what the language will end 10 up being.
11 MEMBER BIER: Well, I suppose --
12 MEMBER ROBERTS: I think rulemaking does 13 have the requirement for the PRA as part of the 14 operating license.
15 CHAIR KIRCHNER: Right.
16 MEMBER BIER: I suppose we could finesse 17 it, by instead of saying at the time of the operating 18 license application, just say prior to fuel load.
19 CHAIR KIRCHNER: No, don't, it's fine.
20 MEMBER BIER: Okay, other comments on this 21 paragraph?
22 MEMBER ROBERTS: You could say as part of 23 the operating license application, that takes away the 24 specific timing. Line 42, the complete PRA, as part 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
19 of, and then delete at the time of.
1 MR. SUNSERI: In line 39, you ought to 2
just start it with the Subcommittee recommends, 3
because you're writing the subcommittee, and you're 4
the chair of it, so.
5 MEMBER BIER: Yeah, that's fine, thank 6
you.
7 MR. SUNSERI: Yeah, put an S after 8
recommend.
9 MEMBER BIER: Yeah. Maybe we should say 10 that the Committee not object.
11 MR. SUNSERI: Yeah, something, has no 12 objections, or --
13 MEMBER BIER: Yeah. So, instead of have 14 no objections, say not object.
15 MR. SUNSERI: Does not, have not, does 16 not.
17 MEMBER BIER: Whatever.
18 MR. SUNSERI: How do you want to?
19 MEMBER BIER: Make objection to object.
20 And I think it's fine to say the Subcommittee 21 recommends that the Committee not object, right?
22 CHAIR KIRCHNER: Not have not.
23 MEMBER BIER: Yeah, so just delete have, 24 and then I think we're okay. Did we want to get rid 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
20 of in particular, and make Bill Gates happy, or keep 1
it? I think it's fine. Okay, any further comments, 2
questions, observations.
3 CHAIR KIRCHNER: Further discussion? Does 4
anyone have any objection to the ISG being issued?
5 Hearing
- none, Subcommittee's recommendation is 6
accepted.
7 MEMBER BIER: Excellent. So, Sandra, we 8
can file and move on. Excellent. Well, that was nice 9
and efficient. By the way, are we taking public 10 comment only at the end of the meeting, or how do we 11 want to do that?
12 CHAIR KIRCHNER: Yeah, I'll --
13 MEMBER BIER: At the end of the morning 14 whenever we --
15 CHAIR KIRCHNER: Yeah, when we finish the 16 next summary. So, what I have asked, members, I have 17 asked Vicki to also go on to a companion topic, which 18 was the PRA and advanced reactor session that we had 19 in the afternoon of May 21 subcommittee, and we could 20 deal with that now rather than in PNP. So, with that 21 I will turn again to Vicki.
22 MEMBER BIER: So, before I ask Sandra to 23 pull anything up, we should probably have a kind of 24 more general discussion first about what level of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
21 detail we want. Vesna and I put together several 1
drafts over the course of the past week, which as 2
everybody knows, is also a good way of thinking.
3 Sometimes you have to write to figure out what you 4
really think.
5 So, we submitted a longer draft to Chris, 6
Chris said this is overly long for PNP, for PNP he 7
wanted a really short, simple, like one paragraph or 8
two paragraph summary. I distributed to the Committee 9
a longer one and a half page version, and we have a 10 still longer version that did not get distributed that 11 has some stronger recommendations. So, I don't know 12 if we want to start with the one and a half pager, or 13
-- okay.
14 CHAIR KIRCHNER: Start with the one.
15 MEMBER BIER: So, Sandra, I think you 16 should have that, right. And if we accept the longer 17 version here as the Committee report, then we can 18 still have this in PNP tomorrow, just as the 19 documentation that the meeting happened. Okay, so 20 before we go through this, am I correct in my 21 inference that these summary reports should not have 22 recommendations, they should just be observations?
23 CHAIR KIRCHNER: In general I would say 24 yes, if it rises to a level where the Committee feels 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
22 very strongly, we have an important recommendation 1
that has a safety consideration, then we should write 2
a letter.
3 MEMBER BIER: Okay, that was what I 4
understood, and Vesna I think has some points that she 5
may want to make as recommendations, so we can discuss 6
those as we get to them. My own sense was that the 7
conversation with staff two weeks ago was very 8
friendly, and open. They were interested in hearing 9
what we had to say, they actually asked for a letter.
10 So, I think they will take the information 11 in the summary report seriously, and we probably don't 12 need recommendations to get them to think about what 13 we want them to think about. So, but we can discuss 14 the recommendations as we go through. So, I will 15 start at the top reading again. The Human Factors 16 Reliability and PRA Subcommittee held a meeting on May 17 21st, 2025.
18 I guess we can say to discuss, let's edit 19 as we go a little bit, it is kind of chunky otherwise.
20 After 2025 put a comma, and say to discuss. And then 21 delete the Subcommittee discussed. Okay, close up the 22 sentence, we don't need a period. Okay, to discuss 23 the use of PRA in support of advanced reactors, 24 including potential improvements or additions to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
23 available guidance.
1 Members Bier and Dimitrijevic presented 2
the technical issues that were identified maybe, not 3
have been. That were identified as needing to be 4
addressed for advanced reactor applicants. In 5
particular risk, I think Vesna probably wants that to 6
say risk importance measures, instead of risk metrics.
7 PRA completeness and uncertainty analysis, and I guess 8
cliff edge effect should also be in there.
9 So, let's say PRA completeness comma, 10 uncertainty analysis comma, just delete the and.
11 MEMBER PALMTAG: And you want that to say 12 risk important measures.
13 MEMBER BIER: Yes, thank you. Well, we 14 can -- okay, uncertainty analysis comma, and cliff 15 edge effects.
16 MEMBER PALMTAG: That's measures.
17 MEMBER BIER: Yeah, we'll get to that, she 18 can only type in one place at a time. Cliff edge 19 effects, yeah. So, now you can go up to risk 20 importance, and say risk importance measures. Okay, 21 additionally ACRS Consultant Bley presented on cliff 22 edge effects. Staff also presented on the following 23 topics, relative and absolute, again, that should 24 probably say risk importance measures instead of risk 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
24 metrics.
1 Sorry for putting it as I read, but okay.
2 Importance, okay. PRA completeness, staff and 3
industry guidance under development, cliff edge 4
effects and uncertainty analysis. It was evident that 5
the staff had considered these topics in great detail, 6
the discussion was productive. I guess Committee 7
positions should be Committee observations on the 8
various topics.
9 After the meeting are summarized below.
10 I don't think we need -- I guess I have two committee 11 notes, okay.
12 CHAIR KIRCHNER: The Subcommittee.
13 MEMBER BIER: After the Subcommittee 14 meeting, yes. On that last line, 17, after the 15 Subcommittee. Subcommittee observations you want to 16 say, or -- yeah, okay. No, delete Subcommittee there, 17 and put sub before Committee on the previous line.
18 Subcommittee, yeah, all right. So, should we go 19 through the whole thing, or take comments on this 20 first paragraph?
21 CHAIR KIRCHNER: Why don't we see the 22 whole thing so we have a feeling for what you're --
23 MEMBER BIER: Okay, yeah. So, importance 24 measures, there was extensive discussion of absolute 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
25 versus relative importance measures. In the history 1
of advanced reactor development there were different 2
goals under consideration.
One preventing a
3 significant decrease in the enhanced levels of safety 4
provided by new reactors, that seems kind of like a 5
double negative to me, or something we can finesse 6
later.
7 And two, providing greater operational 8
flexibility for new reactors with enhanced safety 9
features. The staff stated that they continued to be 10 open to additional ideas as they develop the 11 recommended, integrated, risk informed approach.
12 However, staff emphasized that the identification of 13 safety significant components was not driven 14 exclusively by the quantitative values of importance 15 measures.
16 But also included holistic considerations 17 such as defense-in-depth and the identification of 18 risk significant functions. And to me that last 19 sentence is kind of our way of saying yeah, we agree 20 that this is important without writing a letter to say 21 it. Next paragraph, uncertainty analysis. It was 22 recognized by staff that in addition to parametric 23 uncertainty, model uncertainty and completeness 24 uncertainty could be extremely important.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
26 Potentially more important for advanced 1
reactors than for the current light-water fleet, where 2
there is already extensive operating experience.
3 Often advanced designs rely on passive means, i.e.,
4 natural physical processes, such as natural 5
convection, thermal conduction, radiation, et cetera, 6
to maintain safety functions. I think that should 7
probably just say to maintain safety.
8 You want to go ahead and delete the 9
functions. Because of lack of data and experience, 10 characterization of the uncertainties in the success 11 criteria and passive functional reliability may 12 require special attention, and delete receive. And on 13 the previous line, I think I would delete the before 14 success criteria. Okay.
15 MEMBER PETTI: What do we mean by success 16 criteria?
17 MEMBER BIER: I think that was Vesna's 18 sentence, but what do we mean by success criteria? I 19 mean in a traditional light-water reactor, success 20 criteria would be something like you need two out of 21 three pumps, or whatever, and here I guess it would be 22 things like flow rates, et cetera. But Vesna, if you 23 are online, do you want to expand on success criteria?
24 MEMBER DIMITRIJEVIC: Well, the success 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
27 criteria for passive, which is how are you going to 1
accomplish natural articulation, the cooling vents, 2
and things like that, are you going to -- is that 3
going to go broke, that's basically what it is, it's 4
a basic success of that function. That's why it was 5
functions before.
6 So, you know that in the passive cooling, 7
it's not that just the valves fell off, but that all 8
the design will work as designed, the natural 9
articulation, the heat transfer, things like that.
10 CHAIR KIRCHNER: I can give numerous 11 examples for so called passive systems that can be 12 defeated. A blockage in a flow channel could defeat 13 a passive natural convection path as an example. So, 14 some of the passive design features for decay heat 15 removal actually have a fairly complicated system that 16 can -- yes, gravity is still there, but things can go 17 wrong in the quote unquote passive systems in terms of 18 removing the decay heat, so yeah, there are numerous 19 examples.
20 MEMBER BIER: Yeah, so we are okay to --
21 MEMBER DIMITRIJEVIC: Actually. in the 22 NuScale there is a number for that, I think it was ten 23 to minus seven, that would succeed as the design, both 24 for the decay heat, and for the ECCS systems.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
28 MEMBER BIER: Okay, we're okay with 1
success criteria for now, Dave? We can word engineer 2
later. Okay --
3 MEMBER ROBERTS: I think I would add or 4
inherent to passive, go back up. Because advanced 5
reactors often rely on inherent features, to Walt's 6
example, there are different things for passive 7
features, there are also different things that could 8
abort inherent features such as uncertainty to the 9
role it exists in the extent of their model, and if 10 there's some event that could bypass the inherent 11 features.
12 MEMBER BIER: So, what line number are 13 you?
14 MEMBER ROBERTS: 37, right at the end of 15 37.
16 MEMBER BIER: So, rely on passive or 17 inherent --
18 MEMBER ROBERTS: Passive or inherent.
19 MEMBER BIER: Features, or means, or 20 something, so at the end of 37 add or inherent.
21 MEMBER ROBERTS: Then change the "i.e." to 22 "e.g.," because after comes one example for passive or 23 inherent feature.
24 MEMBER PALMTAG: What does inherent mean, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
29 what is an inherent feature?
1 MEMBER ROBERTS: Things like positive 2
temperature -- negative reactivity feedback or 3
positive temperature.
4 MEMBER PALMTAG: Isn't that passive?
5 MEMBER ROBERTS: I don't know that 6
inherent is a subset of passive or not.
7 MEMBER PETTI: High conductivity in 8
graphite, that's inherent.
9 MEMBER ROBERTS: To me, passive are things 10 like structures that don't need to change state to 11 bring the safety benefit, and it could be thwarted by 12 a natural event, that could destroy the building for 13 example, or that type of thing. Or like Walt's 14 example of blocking a channel. Where it's inherent, 15 it's always there, but there may be an event that you 16 haven't thought of that could cause them to not be as 17 effective as you think. I think inherent is a 18 different thought process.
19 MEMBER BIER: Well, and I certainly think 20 it doesn't hurt us to add it, right? Even if some 21 people interpret it as meaning the same thing, it's 22 good enough. Okay, so now I think we can move down to 23 cliff edge effects. Okay, the discussion clarified 24 that focusing on a specific scenario cut off frequency 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
30 as a way to search for a cliff edge effect seems to 1
be, I guess we could say is.
2 But seems to be both ineffective since it 3
may not capture some cliff-edge effects, but also 4
inefficient and overly burdensome for applicants, 5
since there can be a large number of scenarios above 6
any cut off frequency. Some documents exist that --
7 well, maybe we should say some documents provide, 8
delete exist that.
9 Okay, some documents provide at least 10 partial guidance for more qualitative approaches in 11 looking for cliff edge effects. E.g., and I will let 12 Larry or somebody clean up the references, e.g., the 13 ASME PRA standard, which is what Jon Facemire 14 recommended, and NEI 24-05 regarding emergency 15 planning zones.
16 Staff confirmed that in their view, PRA is 17 not adequate as the only means of identify cliff edge 18 effects, so further guidance on this topic might be 19 worthwhile.
20 CHAIR KIRCHNER: Could we stop here for a 21 moment?
22 MEMBER BIER: Yes, this is a good place to 23 stop actually.
24 CHAIR KIRCHNER: I think yeah, that should 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
31 be spaced. But Dave, I'm sorry, I had great 1
difficulty that day with my internet connection, but 2
if I remember correctly, there was a discussion about 3
looking at cliff edge effects, that this must have 4
been you, and Tom, and Dennis perhaps from a 5
phenomenological kind of approach.
6 Can we capture that here in any way?
7 Because that resonated with me going beyond just the 8
PRA numbers, to conducting a search for these kind of 9
effects. Unfortunately I couldn't participate in that 10 discussion that day, but it struck me that that was 11 something worthwhile to capture here.
12 MEMBER PETTI: Yes.
13 CHAIR KIRCHNER: So that we're not just 14 looking at numbers in a cut off, and things like that.
15 MEMBER BIER: Well, and it goes beyond 16 just looking at numbers and cut offs, because one of 17 the points that came up in the meeting two weeks ago 18 is that there can be cliff edge effects that don't 19 even get into the PRA, because somebody decided 20 they're so unlikely we don't need to model them, but 21 you still might want to look at them for cliff edge.
22 So, maybe one thing to do is after the 23 some documents, those documents are both kind of PRA 24 related, so we could say however these documents focus 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
32 on PRA, staff commented that in their view blah, blah, 1
blah, and then maybe including phenomenological 2
approaches, or something.
3 CHAIR KIRCHNER: This wraps back to the 4
completeness discussion, because if something is left 5
out of the PRA, it's not there.
6 MEMBER BIER: Yeah.
7 CHAIR KIRCHNER: So, if there is some 8
phenomenon that actually could get you to a tipping 9
point in terms of the reactor's response, or release 10 of radio nuclides, whatever the issue is, if it's not 11 in the PRA, you're not going to find it. But one 12 would hope that completing the cycle with the defense-13 in-depth analysis would in effect force you to kind of 14 be searching for these kind of things that might --
15 MEMBER BIER: Well, and PRA completeness 16 is kind of mentioned in the intro, but doesn't have 17 its own little paragraph here, so maybe it would be 18 good to get in the idea of PRA completeness. What?
19 Yes, please.
20 CHAIR KIRCHNER: Come to a microphone.
21 MR.
NOURBAKHSH:
The idea of 22 phenomenological uncertainties on PRA has been 23 addressed during AP 1002, and in a way, even there was 24
-- I did some work that the importance measures for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
33 phenomenological issues, basically looking at the 1
worst case scenario. For example one case would be in 2
vessel melting retention that they have in AP 1000 to 3
prevent vessel failure basically.
4 And they were measured for high 5
degeneration, a lot of phenomenon at issue, and then 6
it could be if PRA practitioners who are familiar with 7
that, they could identify the importance of that issue 8
in PRA, and come up with some kind of importance of 9
that in the result, whatever it is, the metrics you 10 are looking at.
11 An example was some of the delayed 12 containment -- decay heat removal from the containment 13 late, and then basically to hit the words that this 14 phenomenon doesn't happen. It was only thirty percent 15 increase in risk, so there are methods that you can 16 look at, even in passive systems there are -- we can 17 bound it to see how much effect on safety and risk it 18 has, on basically multi-level assessment.
19 The bonding assessment, the plausible, and 20 especially some of this passive system is bonding 21 condition three and two, and under certain conditions 22 they may not watch. And there are some work on that 23 too, but I think there was some work on passive system 24 reliability in the past. So, it is not something that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
34 people are not aware of that.
1 And especially during the AP 1000 PRA 2
level 2, which is a lot of phenomenological issues, 3
these things have been addressed.
4 MEMBER BIER: Thank you. I don't know if 5
we need to go that level of detail on methods for 6
handling the phenomenology, but we should certainly 7
add that in. First, Sandra, can you put a carriage 8
return after line 55 so that we can separate it from 9
the rest of the stuff? Thank you. So, on line 53 10 before staff, I think we can say that however these 11 documents are PRA related.
12 Put a comma after however. Since there 13 can always be concerns with PRA completeness, and some 14 potential cliff edge effects may not be included in 15 PRAs comma. And then a little less for staff. I 16 guess the next line, put a period instead of a comma 17 after cliff edge effects, because it's getting long.
18 Further guidance on this topic comma, yeah.
19 Including consideration of 20 phenomenological effects, is that fair, or do you have 21
-- okay. Yeah, O after the N, I think you're in the 22 right -- no, there we go, take out that O. So, say 23 phenomenon, and then we'll fix it. That's O-N, O, and 24 now just the word logical, phenomenological effects 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
35 comma, might be worthwhile.
1 MR. MARTIN: And you know, to sound like 2
a broken record, and comprehensive hazard analysis.
3 MEMBER BIER: Sure, that's fine.
4 MEMBER PETTI: So, the problem with that 5
is we raised this issue, and I thought the staff 6
agreed.
7 MEMBER BIER: Yeah, you want to make that 8
last sentence kind of more complementary?
9 MEMBER PETTI: Right, right.
10 MEMBER BIER: Okay, that's fine. So, one 11 way to make it more complementary is to put it back in 12 the previous sentence with a comma. Okay, so go back 13 to further on 56, put a comma first before the 14 further. Yeah, a comma before the further, and then 15 little F, we are just merging it back into the --
16 undoing what we just did, as usual.
17 Further guidance, now I would put that 18 including part in parenthesis since the sentence is 19 getting so long. And close paren after effects 20 instead of a comma. And now do we want to include 21 Bob's thought here on comprehensive hazard analysis as 22 part of the parents?
23 MEMBER PETTI: Just the way it is 24 structured, it looks like here is an idea that we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
36 think should be thought about in the future, whereas 1
I want to say PRA is not adequate, but our discussions 2
concern sort of an engineering approach to cliff edge 3
effects that can consider the phenomenology as a 4
complementary approach to the PRA. That was what I 5
took away from the discussion.
6 MEMBER ROBERTS: Yeah, I think the NEI guy 7
said that the integrated decision panel is required by 8
the LMP, so it really is a question of if you look at 9
the LMP document, there is nothing that says how they 10 actually do the assessment of cliff edge effects, and 11 that is kind of the bottom line, is if it's all there, 12 just you have to put together parts of the PRA 13 standard, parts of the integrated decision panel, 14 parts of just what people do as good engineering 15 practice.
16 Then it may be a story already there to 17 put together, and give both the applicants and staff 18 some guidance on what to look for. So, I think the 19 bottom line is the right bottom line, which is 20 considering the need for more guidance. We don't know 21 that there is a gap, we just don't know what they 22 actually do to cover this.
23 MEMBER BIER: Well, and one of the points 24 that Vesna made in our discussion as we got towards 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
37 this document was that documents like the ASME 1
standard say what should be in there, but it doesn't 2
really tell you how to do it. And I guess Jon 3
Facemire would say, well, we're good engineers, we 4
know how to do it.
5 MEMBER ROBERTS: Right, the NEI document 6
says cover all sequences less than cut off, and that's 7
probably impossible, I would say that's where this 8
whole question started from. There is no real 9
guidance in the NEI documents, at least that I could 10 find saying what you do with that, other than you've 11 got to do something.
12 MEMBER BIER: Yeah. So, let's go back to 13 56 after cliff edge effects, maybe put a semicolon 14 instead of a comma, and say there was extensive 15 discussion of the need for engineering analysis.
16 MEMBER HALNON: Based on phenomenological 17 considerations.
18 MEMBER BIER: Of the need for engineering 19 analysis, and Dave?
20 MEMBER PETTI: Based on phenomenological 21 considerations.
22 MEMBER BIER: Okay, just delete until you 23 get to phenomenological so we don't have to spell it 24 again.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
38 MEMBER PETTI: Instead of effects say 1
considerations to complement PRA based approach.
2 CHAIR KIRCHNER: Based approach.
3 MEMBER PETTI: Yeah.
4 MEMBER PALMTAG: That sentence is way too 5
long.
6 MEMBER PETTI: I know, yeah, yeah.
7 MEMBER BIER: Yeah, we'll deal with it.
8 So, you wanted something after approach.
9 MEMBER PETTI: Yeah, but you've got it up 10 in front.
11 MEMBER BIER: Okay, so delete might be 12 worthwhile. And I would say instead of the PRA based 13 approach, the PRA, because the PRA based approach 14 sounds like it's referring to that frequency cut off 15 idea, which we think shouldn't even be part of the 16 approach really. So, just to complement the PRA.
17 CHAIR KIRCHNER: And to address Scott's 18 concern, we could probably put a period on line 56 19 after effects.
20 MEMBER PALMTAG: And I would take the 21 staff confirmed, and put it in the next --
22 MEMBER HARRINGTON: Well, you could put 23 that at the beginning of the -- let me see. Staff 24 confirmed, I lost the word.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
39 MEMBER PALMTAG: Semicolon.
1 MEMBER HARRINGTON: When you say staff 2
confirmed that in their view, since there can always 3
be concerns with PRA completeness pertaining to cliff 4
edge effects, PRA may not be sufficient. And then go 5
on with whatever.
6 MEMBER BIER: Do we want to do that, move 7
staff -- okay. So, staff confirmed that in their 8
view, and paste it at the beginning of the sentence on 9
- 53. So, take it from 55 to --
10 MEMBER PALMTAG: I would almost move that 11 to where the semicolon is.
12 MEMBER BIER: Let's put it one place for 13 now and then look at it. So, move it before sense for 14 now, and then we'll think about whether that's the 15 right place. Comma after view, yeah. Delete the 16 paren at the end of that sentence there, okay.
17 MEMBER HARRINGTON: On 55 right at the 18 beginning I would insert thus, and thus some potential 19 cliff edge effects may not be included.
20 MEMBER BIER: Good.
21 MEMBER PETTI: So, I just think that's an 22 awfully long sentence.
23 MEMBER BIER: It is.
24 MEMBER PETTI: The staff confirmed it in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
40 their view because of concerns with PRA completeness, 1
the PRA is not adequate as the only means of 2
identifying cliff edge effects.
3 MEMBER BIER: Let's do that, you want to 4
drive?
5 MEMBER PETTI: Yeah.
6 MEMBER BIER: Okay.
7 MEMBER PETTI: Sandra, get rid of since 8
there can always be.
9 MEMBER BIER: Yeah, delete there can 10 always be.
11 MEMBER PETTI: Remove there can always be, 12 say because of. Comma after completeness, and then 13 forward delete up to the next comma.
14 MEMBER BIER: I think this is better, and 15 more complementary of staff.
16 CHAIR KIRCHNER: And then on line 55, just 17 end that sentence effects, after effects, period, and 18 then capital there are, or there was.
19 MEMBER PETTI: Then I would put a sentence 20 that while parts of -- there's bits and pieces lying 21 around in different places, we need guidance to put it 22 all together in one place, but I don't know how to say 23 that in a simple way.
24 MEMBER PALMTAG: Somehow guidance got 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
41 taken out of that.
1 MEMBER PETTI: Right, we're still there, 2
yeah.
3 MEMBER BIER: Maybe we can say guidance 4
consolidating the various aspects of this process, so 5
at the end of the paragraph on 57, guidance 6
consolidating the various aspects of this process 7
might be worthwhile. So, we're not writing a letter, 8
but if staff wants to, they can take this to somebody 9
and say see?
10 MEMBER PALMTAG: Didn't staff agree with 11 that?
12 MEMBER BIER: I don't know that I 13 remember, I would have to look at the transcript 14 probably. I have the transcript somewhere, but --
15 MEMBER HARRINGTON:
And given the 16 discussion that maybe some of this does go long, some 17 of it doesn't, rather than saying the need for 18 engineering analysis, maybe the value of engineering 19 analysis. Then it doesn't suggest it's not happening.
20 MEMBER PETTI: Sure, yeah.
21 MEMBER HARRINGTON: So, 56 change the need 22 for to the value of. So, Vicki, lead us on to the 23 path forward.
24 MEMBER BIER: Okay, yeah, sorry, I was 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
42 going to check and see the transcript, but I don't 1
think we really need to do that.
2 MEMBER ROBERTS: I'd just make one 3
observation before we move on, that we are going to 4
review the response per the staff's response to our 5
TerraPower APZ letter in PNP I think next month. I 6
just want everybody to be aware that their letter does 7
say that the PRA is sufficient to do the search for 8
cliff edge effects.
9 So, what I was thinking is we would get 10 Vicki's write up done first, and then we would simply 11 reference it in the assessment of the task response.
12 It's probably too much to put it in this --
13 (Simultaneous speaking.)
14 MEMBER BIER: Okay, thanks for that 15 reminder.
16 MEMBER PETTI: Okay, yeah, but hold on.
17 So we've got different parts of the staff saying 18 different things.
19 MEMBER BIER: Yeah, as usual. That's 20 normal.
21 MEMBER ROBERTS: Yeah, they wrote that 22 letter in February, we had the discussions last month, 23 there was a lot of preparation for last month's 24 subcommittee meeting. And their views evolve, I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
43 is probably an accurate portrayal, but I don't really 1
know that.
2 MEMBER BIER: Okay, now we can put 60 at 3
the top, I guess. Yeah, before we go.
4 MEMBER PALMTAG: Go to 46, I think that 5
but should be and at the end of 46.
6 MEMBER BIER: Okay, that's fine. Okay, 7
now put 60 at the top, thank you. Okay, so it says I 8
will lead a discussion, I guess we can change that.
9 In a discussion, just delete the beginning, and just 10 say in a discussion on next steps and possible future 11 meetings, add possible before future, comma after 12 meetings.
13 Just close up with topics there. Topics 14 suggested by members included with the D, okay. Risk 15 metrics across the plant's life cycle from design to 16 operation, Bob, I will read this, and then allow you 17 to discuss if you want to discuss. How should PRA 18 inform SSC classifications, influence configuration 19 risk management, especially where safety related 20 classification may not map directly to operational 21 significance.
22 I guess there should be a question mark 23 after significance on 67. Thank you. Is existing 24 guidance sufficient to help licensees manage the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
44 unavailability of risk significant but non-safety 1
related SSCs, and this actually kind of ties in with 2
Vesna's ongoing concern about how do we end up with 3
things that are not safety related, but safety 4
significant, or safety critical, or whatever. Bob, do 5
you want to expand on this at all while we're here?
6 MEMBER MARTIN: Sure. This, and actually 7
the next one kind of relate back to the additional 8
comments that I offered, really both for natrium, the 9
last natrium topical that we had, and going back to 10 the increased enrichment. So, if you recall I 11 mentioned the maintenance rule, and having certainty 12 that there will not be unique challenges raised by 13 basically using similar methods in both the design and 14 operability spaces involving risk.
15 Trying to pull back on the specificity, 16 what I had in the additional comments with a broader 17 topic of just looking at the risk metrics that now are 18 going to be used, are they used consistently, where 19 are they different? Ultimately my questions come back 20 to do we have enough guidance on the topic? And so, 21 I thought it would be worthwhile to have the staff 22 come to us, and kind of provide a more holistic 23 explanation of the whole vision across the life cycle.
24 Of
- course, life cycle goes beyond 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
45 operation, but the main areas being designed to 1
operations, and --
2 MEMBER PETTI: You are going to have to 3
help me, because I have no freaking idea what that 4
means. I mean, from an operability perspective, they 5
want flexibility, and the change in risk profile 6
should enable operational flexibility. But to ask the 7
staff to think about what something would mean from an 8
advanced reactor, let's pick one that has never been 9
built.
10 I just think it's a bridge too far, they 11 are going to have to crawl before they walk, before 12 they run.
13 MEMBER BIER: So, one of the ways that I 14 interpret this, and Bob and I discussed it somewhat 15 over lunch yesterday, is especially on the second one, 16 if you look at how things evolved for LWRs, first we 17 had a bunch of deterministic regulations that were 18 kind of pulled out of the ear, the best somebody could 19 do.
20 Then we had PRA, then we went back and 21 realized we can do better on the regulations, maybe 22 some are overly restrictive, and we have more margin 23 than we thought. Here and there there's a few that 24 this valve should really be tested more often, or 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
46 whatever, and we fine-tuned it after we already had 1
pretty good confidence in the PRA.
2 Here, now that after a generation has 3
passed, and the whole agency is on board with PRA, now 4
we are using risk informed where we don't necessarily 5
have confidence in the PRA yet. So, yes, there should 6
be operational flexibility based on margin, but also 7
should there be some conservatism, or defense-in-8 depth, or whatever just in case we haven't thought of 9
everything yet?
10 And so, one example in that line 74 is 11 what about containment, and I
mean obviously 12 functional containment is its own issue, but should 13 there be some areas where we're not trying to risk 14 inform, and shave margin to get down to what we think 15 is kind of minimum acceptable, but allowing some 16 conservatism to remain built in.
17 MEMBER MARTIN: Certainly the last one, to 18 take another step back here for you Dave, it's the 19 question of who owns the margin, right? We are 20 changing something here, and as Vicki brought up our 21 conversation yesterday, if you look at the beginnings 22 of the industry, yeah, I mean we went off a loose 23 regulatory framework at the time with a lot of 24 involvement by AEC, and built some reactors, tested 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
47 them out. There were no rules, right?
1 And then the AEC said, all right, we are 2
going to own margin, and of course created a very 3
deterministic approach. So, the way I see today's 4
greater reliance on risk metrics is going back to that 5
day. And you bring up often the designs we're looking 6
at have a lot of margin, granted, but who is going to 7
own that margin?
8 Will we just say, okay, we're going to 9
ride this for a while, we'll see what people do? And 10 then will the NRC come in there and say we're going to 11 own this at this point, and do the guardrails? Or do 12 we need to start saying something about that now?
13 And, of course, the first topic is we need 14 to look at it across the life cycle, it's not just 15 about design, although we are obviously focused on 16 design. But NEI 1804 makes an acknowledgment about 17 this
- rule, but that's all it is, it's an 18 acknowledgment, there really is no other story beyond 19 it.
20 The second one, again, in the conversation 21 with Vicki yesterday, you know, I was disturbed by the 22 Boeing 737 Max. This comes down to greater 23 integration of risk into the regulatory framework.
24 The FAA allowed it. Of course, it was multiple 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
48 failure problem, but one of them was eliminating 1
single failure and monitoring, and then poor training 2
across the board. Multiple failures. But it began 3
with the regulator maybe going a little bit too far 4
with a risk. And some deterministic guardrails need 5
to remain in there. It needs to be acknowledged.
6 And obviously I focus on the containment. So, those 7
are my topics.
8 CHAIR KIRCHNER:
Can I
make one 9
observation? That whether it's advanced reactors or 10 LWRs, if we put containment for the moment in 11 quotation marks, the advanced reactors are going to 12 have to do a design basis accident analysis comparable 13 to the same requirements as the LWRs. And usually 14 what happens, that determines what things are quote 15 unquote safety related.
16 And so when I look at this, I think they 17 are. I would say let's pick on a reactor type, NHTGR 18 using TRISO particle fuel, that's their containment, 19 right? If you accept functional containment, which is 20 policy with the commission. The fuel is going to be 21 safety related, and that is deterministic in my 22 opinion.
23 So, I'm with you that to demonstrate the 24 design basis accidents are accommodated within the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
49 criteria and 10 CFR 50.34, the 25 rem that we all know 1
about at exclusionary boundary, so I agree, yeah, it 2
should remain deterministic. And from what I see, it 3
will be.
4 MEMBER MARTIN: Well, certainly in that 5
example, absolutely, I agree. I think DOE and NRC 6
have vetted that one for decades, but we're also 7
seeing new ideas that almost seem to be kind of hand 8
waved on this thing, and they certainly should be 9
going down the similar path that HGRs have done there.
10 But anyway, that's one specific thing.
11 MEMBER PETTI: The problem that I have, 12 it's just the way the words are on the page, it sounds 13 like risk informed performance based arguments are the 14 only tool in the toolbox. But defense-in-depth is a 15 critical counterbalance, that's what I was trying to 16 get to when you get to my questions. There's all 17 sorts of weaknesses in using these metrics, in my 18 opinion, when you get to real low probabilities, low 19 frequencies.
20 Whether you believe the numbers or not, 21 how historically they have been used in light-water 22 reactors, they may not work in advanced reactors. And 23 so, maybe we need different criteria to figure out 24 where the margin is, who owns the margin, that was my 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
50 discovery, my sense was not to get so focused on the 1
PRA and its limitations to say -- it always comes 2
across to me as well, then we should just forget this, 3
and just conform stuff.
4 And that's not what we want, because 5
incorporating PRA into the design is what we want 6
designers to do, those are really important things.
7 It just means that how we maybe use the PRA will be 8
different, and we may have to use some of the more 9
historic approaches like defense-in-depth, and safety 10 margin, and engineering judgment.
11 MEMBER MARTIN: Absolutely, nothing you 12 said there that I disagree with.
13 MEMBER PETTI: That context and balance 14 together is what I was trying to --
15 MEMBER ROBERTS: And then Greg and I, last 16 month I presented a draft guide that was going to 17 endorse NEI standard 2205 on 10 CFR 50.59, I think it 18 does an excellent job of portraying exactly what you 19 said. It has got requirements to come to the NRC for 20 things to change risk profile beyond the LMP, but it 21 also requires assessing defense-in-depth, and 22 regardless of whether or not you had something modeled 23 in the PRA, there is also criteria for components or 24 systems that are included for defense-in-depth.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
51 So, I don't see any indication that 1
industry isn't pursuing this. I think they understand 2
this balance of defense-in-depth and safety margins 3
versus the risk analysis. And that's why I kind of 4
wondered whether this is the right time to bring this 5
up, it's an issue from the Committee also, because 6
there is no indication that there is a problem.
7 Just it bears watching, and making sure 8
things progress the way that they seem to be 9
progressing. But I also agree with you, Dave, that 10 it's kind of premature to put part of the operational 11 profile for reactors that haven't even been designed 12 yet.
13 MEMBER BIER: Yeah, I guess given that 14 this is really just a list of topics to be considered 15 in the future, I don't mind leaving it in, it doesn't 16 require the Committee to hurry up and schedule a 17 meeting on this or anything, but one thing we can 18 certainly do on 71 is the role of deterministic 19 guardrails such as defense-in-depth to kind of 20 emphasize that yes, we already have such guardrails.
21 MEMBER MARTIN: Certainly defense-in-22 depth, so one of the points I of course made to you 23 yesterday is the epistemic uncertainty, the unknown 24 unknowns that you can't model. They are relying a lot 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
52 more on models today, and another way to look at this 1
deterministic guardrail is dealing with those unknown 2
unknowns.
3 I mean, no one thought of the scenario 4
that led to TMI, or people had higher confidence of 5
the resilience of Chernobyl and Fukushima, these were 6
outside of PRA space, but yet they happened. And you 7
can go on and on outside of our industry, so we can 8
rephrase these sort of things, but the true 9
completeness of PRA is to also address what's not in 10 the model, but is unknown.
11 And the only way to do that is to have 12 some deterministic guardrails, that at least when 13 you're challenged by the public, wherever they may be, 14 that you can say yes, you've done it. I focused on 15 the containment, now that may not be the only place.
16 But when I think about what we're doing on the fuel, 17 and again I'm thinking LWR fuel and siding, what comes 18 in between there?
19 It's the containment. And if you really 20 want to relax those other two, I feel like the obvious 21 one that you don't is containment. That is just where 22 I land, and I have said it a few times, but you're 23 probably tired of listening to me.
24 MEMBER PETTI: What came across to me with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
53 the whole containment approach is have you heard of 1
what's called the strong box theory of safety? You 2
ever heard this?
3 MEMBER MARTIN: No.
4 MEMBER PETTI: I build a strong box, it's 5
impenetrable, and there are certain designs out there 6
that I've seen that made me think about this, so let 7
me do whatever the hell I want to do inside the box.
8 Now, that is not how we think of nuclear safety, 9
defense-in-depth, multiple layers. But that's what I 10 reacted to when I saw this containment as a guardrail.
11 It made me think that well we can do 12 anything we want, but that's not really -- I mean, so 13 again, this is how the questions are written in the 14 context is what I worry about, it conveys so many 15 different things to so many different people, that's 16 what bothered me.
17 MEMBER BIER: So, maybe one way is just on 18 74 we could say as one example, could containment 19 remain as blah, blah, blah.
20 MEMBER MARTIN: Like I said, I'm biased 21 towards mention of containment, but I also acknowledge 22 there is different ways to solve the problem. I just 23 don't want to see -- I want to see the epistemic 24 uncertainties addressed, and I only -- and it has to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
54 be done -- deterministic complement, maybe guardrail 1
is too strong a word, but I'm certainly happy to work 2
through the wording here if we can come to some 3
agreement, some common understanding, and we can pull 4
back on the details.
5 MEMBER ROBERTS: It's the same as the 6
cliff edge argument, I think it's the exact same 7
argument, it's just on the deterministic assessment of 8
defense-in-depth, and you figure out here is the full 9
range of phenomenology that we can conceive of, and 10 here is the barriers that are effective against that 11 full range, that is kind of the deterministic 12 guardrail.
13 The problem even with Dave's strong box 14 theory is that the strong box may not be as strong as 15 you think it is, and that's what happened in the 60s, 16 where the AEC found out that containment wasn't quite 17 as impenetrable as they thought it was. So, even your 18 strong box --
19 (Simultaneous speaking.)
20 MEMBER PETTI: Well, that accident, the 21 little submersible thing, Ron will remember, designed 22 with a carbon fiber composite, right? And didn't 23 follow any design rules from ASME. And there's a 24 flaw, and it propagated quickly, and it killed them 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
55 all.
1 CHAIR KIRCHNER: A better example is 2
carbon fiber bicycles.
3 MEMBER BIER: I guess one thing, I'm less 4
concerned here about getting the words exactly right, 5
because these are just notes to ourselves for future 6
topics, and if we decide to have such a meeting, there 7
will be informal discussions to clarify exactly the 8
scope of the meeting. But I think certainly we could 9
make the containment sentence be a for example rather 10 than a should.
11 MEMBER MARTIN: You are proposing the 12 simplest change?
13 MEMBER BIER: Yeah.
14 MEMBER PETTI: Well, I'm thinking on the 15 previous one, it's not how should they influence, but 16 can they be used to influence. Because in some places 17 that may not be the right way to do it. I don't want 18 it to be either or, I want it to be is it the right 19 thing to do, is there another thing that can 20 complement it, sort of thing.
21 MEMBER MARTIN: What is the role of SSC 22 classifications in configuration risk management.
23 MEMBER BIER: Yeah, that's great.
24 MEMBER PETTI: Yeah, I think instead of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
56 being -- all right.
1 (Simultaneous speaking.)
2 MEMBER MARTIN: Sandra, replace how should 3
on line 65 with is a role of, and then replace 4
influence with in, how is that?
5 MEMBER BIER: That's great, that works.
6 MEMBER PETTI: Yeah.
7 (Simultaneous speaking.)
8 MEMBER PALMTAG: It's just I'm not sure 9
what the purpose of this is, that I mean this is good 10 brainstorming, but do we want a PNP document of things 11 we might want to talk about in the future? I mean, it 12 just seems --
13 MEMBER MARTIN: We capture it though.
14 MEMBER PALMTAG: Well, do we need to 15 capture it? I mean, these are good ideas, but maybe we 16 need to -- while I'm on board, do we really want to 17 have a meeting --
18 MEMBER PETTI: Let them age like fine wine 19 before we --
20 MEMBER PALMTAG: I mean, we are not 21 committing to these, this is just brainstorming, I 22 don't know if brainstorming needs to go in PNP.
23 MEMBER MARTIN: What does PNP stand for?
24 MEMBER PETTI: Planning and procedures.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
57 MEMBER MARTIN: Planning.
1 MEMBER PALMTAG: This isn't even at the 2
planning stage, this is like brainstorming for future 3
plans.
4 CHAIR KIRCHNER: It's soft enough with the 5
introduction that possible future meetings suggested 6
by members, let's see what Dave had to say. We've got 7
two, how many more are there?
8 MEMBER BIER: I think there's really only 9
the one more, and then open discussion. But okay, so 10 put advanced reactors at the top, 77.
11 CHAIR KIRCHNER: Just one more, okay.
12 MEMBER BIER: Yeah. So, advanced reactors 13 and PRAs suggested by Dave, what are the roles of risk 14 importance measures, e.g., RAW and Fussell-Vesely 15 versus defense-in-depth and safety margin for plants 16 with extremely low risk profiles. Should such plants 17 have greater operational flexibility, and if so, what 18 is the role of operating experience in justifying 19 that? See attachment for details.
20 They have provided a page or two on this 21 that I didn't try to summarize in a bullet, but --
22 MEMBER MARTIN: Well, it's defense 23 operational flexibility, and it kind of touches on my 24 first one, I'm just a little bit more specific. But 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
58 maybe we can merge it in together, and make more 1
people happy.
2 MEMBER BIER: Well, I'm not sure that it's 3
worth the word engineering to merge them, because if 4
these are just notes to ourselves, I mean when we get 5
around to organizing a meeting, if and when, we will 6
merge them at that time.
7 MEMBER SUNSERI: Let me ask a question.
8 What do you hope to accomplish by having these, what 9
is the purpose for having these?
10 MEMBER BIER: I mean I think it's kind of 11 consistent with Bob's comment, is just capturing the 12 thought process now so that if at some time in the 13 future we decide yeah, we really need to dig into 14 this, we remember what we were thinking.
15 MEMBER SUNSERI: Okay, and that's fine, 16 that could be captured in your notebook, or emails, or 17 whatever. But the other part of this is what I'm 18 seeing here is really questions that the staff and the 19 applicants need to address, or potentially could 20 address in their presentations. We're not going to 21 solve the generic issues unless you're expecting a 22 letter report to the commission saying here's a policy 23 issue.
24 The Committee is not here to solve world 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
59 hunger and every question that's out there, but you 1
can ask the question of applicants, and these are the 2
types of questions that I would especially, like the 3
risk management of the systems important to safety or 4
non-safety, certainly ask how are you addressing that.
5 And you may come up with a potpourri of different ways 6
of doing it that all are acceptable, or maybe one is 7
not based on collective judgment.
8 So, I'm not -- putting that in PNP, I 9
guess that's one way to do it, but we're going to talk 10 a bit later, there is also a provision in the bylaws 11 where you can write a white paper basically to the 12 Committee, which is something that you're sort of 13 doing, but you're connecting it to a reactor review, 14 maybe a white paper would even be more appropriate to 15 the Committee, that we could hold a conversation.
16 Or you could go on and do what you just 17 did, call for a subcommittee. But recognize we are 18 looking at these advanced reactors, and their direct 19 safety case of the principle safety functions, and I 20 think some of these you can make and break attachment 21 to that. But some of them are just questions that you 22 want to see, well, how are you addressing this?
23 MEMBER BIER: I mean, in terms of why the 24 idea of future topics was there initially, when we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
60 arranged the meeting that happened two weeks ago, 1
there was a question like will we need a future 2
meeting, will we be able to discuss everything we want 3
to discuss in that one afternoon? And my take is yes, 4
we got some topics for future meetings.
5 But they're not at the stage of ripeness 6
of oh my gosh, we have got to try and schedule this 7
for July or August because we really need to nail this 8
down. It is more like as we see future applications 9
roll in, some of these questions may be fine-tuned in 10 our minds, and at that point we may want a meeting.
11 MEMBER SUNSERI: Well, recognizing the EL 12 in the corner, future meetings on discretionary topics 13 14 MEMBER BIER: Yes, may not happen.
15 MEMBER SUNSERI: So, just to put that out 16 on a table, so that's why later this afternoon when we 17 get discussions about how this is going to affect our 18 future, we may want to talk about what the best place 19 to put this is, and or how to make sure that it is in 20 front of us on future applications. I know this is 21 probably getting to problem solving, I will just make 22 one statement.
23 We do have our twin site that has a lot of 24 folders in there, placeholder for the future topics, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
61 and meeting stuff, I'm looking at the whole list right 1
now, you could put a folder out there.
2 MEMBER BIER: So, two things, first of 3
all, I think we can delete everything after 81, 4
because --
5 CHAIR KIRCHNER: I would agree.
6 MEMBER BIER: Because we're not going to 7
have a letter, and there don't seem to be a lot of new 8
topics being raised right now to capture. And if you 9
scroll up to okay, maybe the way to finesse this in 10 terms of the EO is not to say possible future 11 meetings, but in a discussion on next steps, and 12 topics to bear in mind in reviewing advanced reactor 13 applications, and then we can have the same list.
14 MEMBER SUNSERI: And I think that's great, 15 because if down the road, five years from now some of 16 us aren't here, this will be in the folder, and our 17 staff would have it be -- and our staff could -- some 18 of these things may be solved by an applicant coming 19 in with a novel way of doing it.
20 MEMBER BIER: Right, yeah, and I agree 21 that it's not at a timeliness of yeah, we really need 22 to jump on these, and organize a meeting.
23 MEMBER SUNSERI: Yeah, I mean they're 24 great questions, I would love to hear how each of the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
62 applicants kind of deal with that, and some of them at 1
this stage, at this EP, they might not be at the risk 2
management of their systems yet, but certainly that's 3
an interesting thing in an operating license, for 4
sure.
5 MEMBER BIER: Yeah. So, on 61, in a 6
discussion on next steps and -- so, delete possible 7
future meetings. And now say and considerations to 8
bear in mind in reviewing applications for advanced 9
reactors. You don't need the reviewing, just advanced 10 reactors. And bear should be B-E-A-R, that's okay.
11 MEMBER PETTI: I think wouldn't just limit 12 it to advanced reactors, because some of the examples 13 that Bob had were LWR potentially. So, just future 14 licensing applications.
15 MEMBER BIER: That's great. Okay, so --
16 MEMBER MARTIN: I would suggest taking out 17 on next steps.
18 MEMBER BIER: Yeah, we don't need next 19 steps, yeah.
20 MEMBER SUNSERI: That's part of the AP 21 1000, sort of a similar, but they're already 22 established, maybe we should find out how Vogtle is 23 managing some of these questions.
24 MEMBER HALNON: That's a good point, I've 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
63 always felt that the best test of any of the guidance 1
is to just take an existing reactor, and run the 2
reactor through the guidance, and see what you're --
3 (Simultaneous speaking.)
4 MEMBER PETTI: I thought there was also --
5 I also thought there was some discussion about running 6
a tabletop LMP, take a large PWR, what would it mean?
7 And how would it be different? That would be 8
interesting.
9 MEMBER HALNON: The Committee, as LMP was 10 rolled out and such, I remember that the Committee 11 repeatedly objected to non-LWR, the labels, and titles 12 of guidance documents because you've got something to 13 try it out on, and see if it works, that exists, where 14 you have operational experience to inform your 15 tabletop exercises.
16 And it seemed -- I still to this day, here 17 is the question for you, Vicki, why do you need a non-18 PWR standard for PRA? PRA to me, doesn't know what 19 the technology is. The metrics that you might want to 20 use to evaluate versus the quantitative safety goals 21 may be different, but PRA fundamentals, they don't 22 know what the technology is, or the coolant, or the 23 fuel. That's where you put into the PRA model.
24 MEMBER BIER: So, to clean up that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
64 sentence on 61, delete next steps, and yeah, put 1
beyond back in. And before applications, put 2
licensing, and delete for advanced reactors. One 3
thing we could say here to address Greg's concern is 4
before that in the discussion, we could say there was 5
no need identified for a future meeting at this time 6
or something. Or is that kind of implied?
7 MEMBER SUNSERI: I think it's implied in 8
reviewing license applications.
9 MEMBER BIER: That we're not going to have 10 a meeting at least.
11 MEMBER SUNSERI: Yeah, and that will allow 12 you, when it's relevant you can bring it up.
13 MEMBER BIER: Okay. So, there was one 14 place that we still needed to word engineer --
15 MEMBER HALNON: You probably don't want to 16 identify our members, because they may get the 17 midnight phone call.
18 MEMBER BIER: Yeah, that's fine. So, 19 delete the member names in parents, okay, and the next 20 one.
21 MEMBER HALNON: But we will refer them to 22 you --
23 (Simultaneous speaking.)
24 MEMBER BIER: If we get a late night phone 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
65 call. Okay, I think that's it, and scroll. There's 1
one place near the beginning that there was a sentence 2
we wanted to word engineer still, any other comments 3
before we go back and do that? Okay, so the paragraph 4
that was labeled importance measures, so one down from 5
where you are, there we go.
6 So, the bullet one, preventing decrease, 7
it seemed a little weird to me. It could maybe say 8
preserving the enhanced levels of safety or something, 9
is that good enough? Vesna, I think this was your 10 sentence originally, are you okay with preserving 11 instead of preventing a decrease?
12 MEMBER DIMITRIJEVIC: Yeah, absolutely.
13 I mean, this comes directly from the document, the 14 quoted -- but you know, it doesn't matter, it has the 15 same meaning.
16 MEMBER BIER: Okay, yeah. So, change 17 preventing to preserving. And then delete a 18 significant decrease in. And in the previous line, I 19 might say competing goals, not different goals. Okay, 20 let's do that, competing instead of different goals.
21 Because one goal is if we have so much margin, let's 22 enjoy it, and be extra safe.
23 And another version is we have so much 24 margin that we can have more flexibility, and eat up 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
66 part of that margin. But yeah, I think we are good on 1
this. Any further comments or discussion?
2 MEMBER MARTIN: Just for connectivity, 3
should the title be risk important measures?
4 MEMBER BIER: Yes, probably.
5 MEMBER MARTIN: You can shorthand it 6
throughout, I don't care, but --
7 MEMBER BIER: That's okay. Especially 8
since risk is not in the first sentence, so. Any 9
future discussions?
10 CHAIR KIRCHNER: Members, any further 11 commentary? I would just suggest that this be then 12 entered into our minutes in the meeting summary.
13 MEMBER BIER: Excellent. So, Sandra, 14 again, you can save, and move on.
15 CHAIR KIRCHNER: Thank you, Vicki, and 16 Vesna, and Bob, and Dave.
17 MEMBER BIER: And Dave. And everybody 18 else, everyone who helped pivot and finesse things.
19 CHAIR KIRCHNER: Everyone who contributed 20 to that, yes, and Dennis. So, with that we are 21 probably should take public comments now, and then I 22 will just lay out what I see as the agenda for the 23 rest of our meeting. So, if there is anyone out there 24 who wishes to make a comment, please just identify 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
67 yourself, affiliation as needed, and make your 1
comment.
2 So, hearing none, okay. So, this is --
3 we'll stop our meeting today, and recess for the rest 4
of the morning and afternoon, and reengage tomorrow 5
for our planning and procedures meeting at 0830 6
tomorrow morning. At this point, correct me, but I do 7
not think we need the court reporter?
8 Yes, so thank you for your services, and 9
with that, we will take a recess from this meeting.
10 And then I just have some announcements 11 I'd like to make to members and staff. Okay, we are 12 in recess.
13 (Whereupon, the above-entitled matter went 14 off the record at 10:12 a.m.)
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