ML20335A521
| ML20335A521 | |
| Person / Time | |
|---|---|
| Issue date: | 09/24/2020 |
| From: | Weidong Wang Advisory Committee on Reactor Safeguards |
| To: | |
| Wang, W, ACRS | |
| References | |
| NRC-1107 | |
| Download: ML20335A521 (119) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Kairos Power Licensing Subcommittee Docket Number:
(n/a)
Location:
teleconference Date:
Thursday, September 24, 2020 Work Order No.:
NRC-1107 Pages 1-89 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 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
(ACRS) 5
+ + + + +
6 KAIROS POWER LICENSING SUBCOMMITTEE 7
+ + + + +
8 THURSDAY 9
SEPTEMBER 24, 2020 10
+ + + + +
11 The Subcommittee met via Videoconference, 12 at 2:00 p.m. EDT, Dave Petti, Chairman, presiding.
13 COMMITTEE MEMBERS:
14 DAVE PETTI, Chairman 15 RON BALLINGER, Member 16 CHARLIE BROWN, Member 17 VESNA DIMITRIJEVIC, Member 18 WALT KIRCHNER, Member 19 JOSE MARCH-LEUBA, Member 20 JOY REMPE, Member 21 PETE RICCARDELLA, Member 22 MATT SUNSERI, Member 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
2 ACRS CONSULTANTS:
4 DESIGNATED FEDERAL OFFICIAL:
5 WEIDONG WANG 6
7 NRC STAFF PRESENT:
8 ANTONIO BARRETT, NRR/DANU/UART 9
BEN BEASLEY, NRR/DANU/UARL 10 THOMAS DASHIELL, ACRS/PMDA 11 STU MAGRUDER, NRR/DANU/UARL 12 SCOTT MOORE, ACRS 13 DEREK WIDMAYER, ACRS/TSB 14 15 ALSO PRESENT:
16 JORDAN HAGAMAN, Kairos Power 17 DREW PEEBLES, Kairos Power 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
3 C-O-N-T-E-N-T-S 1
PAGE 2
ACRS Chairman Introductory Remarks 6
3 NRC Staff Introductory Remarks 7
4 Kairos Power Introductory Remarks........
9 5
KP-FHR Risk-Informed Performance-Based 6
Licensing Basis Development Methodology 7
Topical Report (KP-TR-009)
........... 10 8
KP-FHR Risk-Informed Performance-Based 9
Licensing Basis Development Methodology 10 Topical Report Safety Evaluation
........ 55 11 Public Comments................. 65 12 Committee Discussion
.............. 68 13 Adjourn..................... 89 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
4 P R O C E E D I N G S 1
(2:00 p.m.)
2 CHAIRMAN PETTI: The meeting will now come 3
to order. This is a meeting of the Kairos Power 4
Licensing Subcommittee of the Advisory Committee on 5
Reactor Safeguards. I'm David Petti, chairman of 6
today's subcommittee meeting.
7 ACRS members in attendance are Charles 8
Brown, Jose March-Leuba, Joy Rempe, Matt Sunseri, Pete 9
Riccardella, Ron Ballinger, Walt Kirchner, and Vesna 10 Dimitrijevic. Consultant Mike Corradini and --- I 11 didn't see Steve Schultz but he may be on. Weidong 12 Wang of the ACRS is the Designated Federal Official 13 for the meeting.
14 During today's meeting, the subcommittee 15 will review Kairos Power's topical report KP-FHR Risk-16 informed Performance-Based Licensing Basis Development 17 Methodology, Revision 1. The subcommittee will hear 18 presentations from Kairos Power representatives and 19 the NRC staff and any other interested persons 20 regarding this matter. The rules for participation in 21 all ACRS meetings, including today's, were announced 22 in the Federal Register in June, 2019. The ACRS 23 section of the U.S. NRC public website provides our 24 charter bylaws, agendas, letter reports, and full 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
5 transcripts of all full and subcommittee meetings 1
including slides presented there. The meeting notice 2
and agenda for this meeting are also posted there.
3 We've received no written statements or 4
requests to make an oral statement from the public.
5 However, today's meeting is open to public attendance 6
and we have a public line.
7 The subcommittee will gather information, 8
analyze relevant issues and facts, and formulate 9
proposed positions and actions as appropriate for 10 deliberation by the full committee. A transcript of 11 the meeting is being kept and made available as stated 12 in the Federal Register. I ask that all participants 13 identify themselves and speak with sufficient clarity 14 and volume so that they may be readily heard.
15 Presenters should speak slowly and tell the listeners 16 what slide they are on to ensure an efficient virtual 17 meeting.
18 We will now proceed with the meeting and 19 I'd like to start by calling up NRR staff.
20 MR. BEASLEY: Thank you. This is Ben 21 Beasley. I'm the branch chief for the Advanced 22 Reactor Licensing Branch. Good Afternoon. It is good 23 to meet with you today. The staff is looking forward 24 to our discussions and to receive feedback from ACRS 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
6 members today on the draft safety evaluation for the 1
Kairos Power topical report on a Risk-Informed 2
Performance-Based Licensing Basis Development 3
Methodology. As you will hear, this topical report 4
describes Kairos' methodology for implementing the 5
industry-developed Licensing Modernization Project 6
which we will refer to in shorthand as LMP.
7 This meeting is the second time that the 8
staff in Kairos Power have had the opportunity to 9
brief the ACRS on Kairos Power topical reports. The 10 first meeting was held in February of this year, and 11 the staff appreciated the helpful comments from the 12 ACRS on the reactor coolant and the scaling 13 methodology topical reports.
14 We do look forward to working with 15 Chairman Petti and the rest of the members and staff 16 over the next several years as we complete reviews of 17 more Kairos Power topical reports and prepare for 18 license applications with the Kairos Power design. I 19 also want to make sure I thank the technical staff 20 from the Advanced Reactor technical branch for their 21 good work producing a high quality safety evaluation.
22 And I also want to note that the working relationship 23 between the staff and Kairos was excellent, and this 24 review was completed without the need for RAIs, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
7 Requests for Additional Information.
1 So with that, I think I may turn it over 2
to Stu Magruder.
3 MR. MAGRUDER: Thanks, Ben. I don't have 4
any comments now. I think I will --- let me introduce 5
myself I guess. This is Stu Magruder. I'm the lead 6
project manager for Kairos for the NRC. And I don't 7
want to add anything now. I'll have an introduction 8
when the staff makes its presentation on our review of 9
the topical, so I guess I'll turn it over to Kairos 10 now.
11 MR. PEEBLES: Alright, thank you, Stu.
12 And good afternoon, everyone, my name is Drew Peebles, 13 I'm the manager of safety integration at Kairos Power.
14 We're here today to give you some background 15 information on our topical report titled Risk-Informed 16 Performance-Based Licensing Basis Development 17 Methodology. We submitted this topical to the NRC in 18 August of last year and just recently received their 19 draft safety evaluation report.
20 Before we get started I would like to 21 thank the ACRS members for their time and interest in 22 Kairos Power. As Ben mentioned, this is our second 23 time before the committee to present on our topical 24 reports, and we look forward to future interactions on 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
8 our licensing submittals.
1 I'm here today with Jordan Hagaman, our 2
manager of reliability engineering, who will also be 3
presenting. Also from the reliability engineering 4
team are Matt Denman and Matt Warner. We are also 5
joined by Peter Hastings, our vice president of 6
regulatory affairs and quality, Darrel Gardner, our 7
senior director of licensing, and Nicole Schlichting, 8
a licensing engineer. I would also like to thank the 9
NRC staff for their thorough and efficient review of 10 the topical.
11 So with that, we are ready to get into the 12 presentation, if that is good, Chairman Petti.
13 CHAIRMAN PETTI: Go ahead.
14 MR. PEEBLES: So Kairos Power is a mission 15 driven company, so we like to begin all of our 16 presentations with our mission statement, which is to 17 enable the world's transition to clean energy, with 18 the ultimate goal of dramatically improving people's 19 quality of life while protecting the environment.
20 The methodology in this topical report is 21 an important step in achieving this mission. The 22 methods that we are leveraging from the LMP provide us 23 with a systematic methodology to create a cohesive and 24 robust safety case for our technology.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
9 So a quick look at the agenda. We just 1
completed introductions and opening remarks. Next, I 2
will provide a quick background on where the content 3
of the topical comes from as well as our justification 4
for creating the topical rather than just utilizing 5
NEI 18-04 as-is. And then I will hand it over to 6
Jordan, who will walk us through a more detailed 7
comparison between the NEI document and our topical, 8
which is KP-TR-009-NP.
9 So the methodology presented in the Kairos 10 topical replicates most of the guidance developed by 11 the Industry-Lead Licensing Modernization Project, or 12 LMP, which was formed to help modernize the licensing 13 framework for advanced non-light water reactor 14 technologies. The methodology in our topical is not 15 new to the ACRS, so I won't spend a lot of time on the 16 background, but I would like to quickly point out the 17 documents that precede our topical.
18 The LMP team produced several white papers 19 that were reviewed by the ACRS, including the 20 selection of licensing basis events, the probabilistic 21 risk assessment approach, a safety classification and 22 performance criteria for structures, systems, and 23 components, and a risk-informed and performance-based 24 evaluation of Defense In-Depth adequacy.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
10 The LMP team sought NRC endorsement of 1
this guidance, so they integrated the content from the 2
white papers into a single guidance document, which is 3
NEI 18-04, and that's titled Risk Informed 4
Performance-Based Technology Inclusive Guidance for 5
Non-Light Water Reactor Basis Development. The ACRS 6
also reviewed this report, and the NRC ultimately 7
endorsed the guidance in Reg Guide 1.233.
8 So that brings us to the Kairos topical.
9 The endorsed guidance in NEI 18-04 is replicated in 10 our topical report. We could use the NEI 18-04 11 document in an application, but since this is a new 12 methodology, there were some clarifications and minor 13 changes that are specific to Kairos strategies that we 14 wanted to make, and we wanted early agreement with the 15 NRC on those changes. The Kairos licensing strategy 16 is all about reducing programmatic risk as early in 17 the process as possible. So our motivation for 18 recreating the guidance was not to develop a new 19 method, but rather to point out some differences that 20 bring it in line with our licensing strategy, so that 21 we get that up front agreement with the NRC staff on 22 those points instead of waiting until we submit an 23 application.
24 So the rest of the presentation is going 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
11 to go through those differences and why we felt we 1
needed to make them. Before I hand it over to Jordan 2
to go over those differences, I'll reiterate the 3
regulatory ask from the topical, which is that after 4
reviewing the deltas between our report and NEI 18-04, 5
that the NRC would still consider this methodology an 6
adequate means to define and evaluate our licensing 7
basis events to get the safety classification for our 8
SSCs and assess Defense In-Depth adequacy for our 9
technology.
10 So I'll pause there before I hand it over 11 to Jordan and see if there are any questions.
12 MEMBER REMPE: Drew, this is Joy. When I 13 was looking through your report, I was interested in 14 the information on page 29. Where are you --- you 15 talk about you're going to have an additional event 16 list of LBEs, and then of course you will have the 17 design maturing and the level of detail the PRA would 18 become more expanded. Where are you in the process?
19 Are you going to have additional clarifications later 20 on for this topical report, or you think you are far 21 enough in the process that you don't need to make any 22 additional changes?
23 MR. PEEBLES: We're still early in the 24 process. We did perform a pilot of the LMP process 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
12 with the southern team as part of the LMP efforts when 1
they were creating NEI 18-04. So we think we have a 2
good idea of how we are going to implement it. But 3
that should be in future licensing interactions.
4 MEMBER REMPE: Thank you.
5 MR. PEEBLES: All right, so with that 6
background in mind, I'll hand the presentation over to 7
Jordan and he'll go over a more detailed comparison of 8
our topical and NEI 18-04.
9 MR. HAGAMAN: Thank you, Drew. The Kairos 10 Power's topical report replicates the methodology in 11 NEI 18-04, but there are some key underlying 12 differences that will be reflected in the presentation 13 of this comparison. One of the observations is that 14 NEI 18-04 has language that's aimed at two separate 15 audiences. It's aimed at both the developers that 16 need to stand up design processes to iterate between 17 design and analysis for a
particular reactor 18 technology.
And the second audience (audio 19 interference) will review the design of the final 20 safety case. That's NEI 18-04.
21 For our topical report, we have just one 22 purpose: to develop a common expectation with the 23 regulator on how a complete presentation of the final 24 design and the final safety case that'll look like for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
13 the KP-FHR. So a lot of the changes in content and 1
the content that didn't get ported over to our topical 2
report is based on this important distinction. KP-TR-3 009 was written to mirror the structure and the 4
content of NEI 18-04 as closely as possible so that 5
it's easy to conclude that the methodology is the same 6
with minor changes. So this presentation will 7
describe where the documents are similar and highlight 8
where applicant-specific deviations were necessary.
9 There were many editorial changes that 10 won't be presented in this analysis of the 11 differences.
Those editorial changes include 12 reformatting. They include any identifying language 13 that indicates that Kairos Power is the applicant as 14 opposed to (audio interference) which simply refers to 15 an applicant or a vendor. And there is a number of 16 just grammar and syntax corrections that we won't talk 17 about where we try to adhere more to our internal 18 style and grammar standards. So, some examples of 19 that are: we say 'units' instead of 'modules,' and we 20 use more definitive language like 'is' or 'are' 21 instead of 'should be' statements.
22 The rest of the presentation are going to 23 be organized into three sections that represent the 24 three primary technical areas in the methodology.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
14 That is: the selection of licensing basis events, the 1
safety classification of structure systems and 2
components, and the evaluation of Defense In-Depth 3
adequacy.
4 So the first section is licensing basis 5
event selection. Can we get the next slide please?
6 MR. PEEBLES: And Jordan, just a reminder 7
to call out the slide number for the people on the 8
phone.
9 MR. HAGAMAN: Okay, so we are on slide six 10 now. Slide six provides difference analysis between 11 the table of contents for section three in NEI 18-04 12 and section three of the topical report. And just 13 reviewing the table of contents, you can conclude that 14 the headings and the subheadings have direct alignment 15 and we point out where there is some differences.
16 So for example, section 3.2 where NEI 18-17 04 was written broadly for an audience of different 18 technology vendors in the Advanced Non-LWR field, we 19 were aimed at just the single technology. So we don't 20 say 'Advanced Non-LWR LBE Selection' we just say 'LBE 21 Selection Approach.'
22 Section 3.2.3 we made a minor editorial 23 change. Instead of saying 'Design and Licensing 24 Stages,' we only say 'Design Stages.' We are not 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
15 committing to any iteration in licensing stages. We 1
do not want to set an expectation that documentation 2
will be available for all iterations, and we don't 3
want to confuse the internal product development 4
process. Which specific licensing actions (audio 5
interference). Similarly, to set the change in 6
section 3.2 and 3.3.2, instead of saying 'Non-LWR PRA 7
Scope' we simply have the PRA Scope that applies to 8
our technology.
9 Section 3.3.4, there is an editorial 10 change where instead of saying 'PRA Safety Functions' 11 as NEI 18-04 uses, we simply use the phrase 'Safety 12 Functions.' And we'll get into that --- we'll 13 elaborate on that in the next slide.
14 Finally, section 3.3.5 talks about the 15 Selection of Risk metrics for PRA Model Development.
16 Rather than give the impression that we're presenting 17 a methodology for selection, we are presenting in 18 section 3.3.5. what our risk metrics will be for PRA 19 model development. So it's less about the selection 20 process and more about communicating a commitment of 21 which metrics we're using.
22 So with that overview, we can go into the 23 next slide and talk a little bit more about the 24 similarities and the Kairos specific implementations.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
16 So we are now on slide 7.
1 As you can see, the similarities between 2
18-04 and our topical report overwhelm the Kairos-3 specific implementations. We use the same definitions 4
for licensing basis events, whether they are AOOs, 5
DBEs, BDBEs, or DBAs. We use the same definition of 6
Frequency-Consequence target criteria.
Both 7
methodologies use the PRA in the LBE selection 8
process. The PRA scope that's appropriate for both 9
methodologies includes both internal events and 10 external hazards. All reactor safety functions in the 11 safety case correspond to functions modeled in the 12 PRA. We have the same overall plant risk metrics 13 defined and risk-significance evaluations. And our 14 importance measures are selected from the list of 15 possible measures given in 18-04.
16 To talk about the Kairos-specific 17 implementation details, you'll notice the first two 18 bullets directly come from our approach to use this 19 methodology to confirm the safety case, rather than 20 give the impression that the methodology is creating 21 the safety case.
22 So the first example of this is we, 23 throughout the document, we replace phrases such as:
24
'LBEs identified in the PRA,' we replaced a phrase 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
17 like that with 'LBEs corresponding to event sequence 1
family in the PRA.' The process of developing a design 2
3 DR. CORRADINI: Can I just ask you a 4
question right here? This is Corradini. Does that 5
mean how you are going to develop the event sequence 6
families are different, or are you just trying to be 7
more careful about the wording? I took this to mean 8
that you might have a different approach than the NEI 9
document. Am I incorrect?
10 MR. HAGAMAN: The actual process of 11 connecting event sequence families to licensing basis 12 events is the same across both methodologies. We are 13 trying to be careful with the wording because we don't 14 want to give the impression that every LBE was first 15 identified in the PRA. The process of developing the 16 design in the safety case is highly iterative. We 17 have rapid iterations, and in practice the original 18 identification of any particular LBE may be the result 19 of a HAZOP, may be the result of engineering 20 judgement, or it may be from PRA insights. And we 21 don't think it is necessarily important that the LBEs 22 were originally identified in the PRA. What we ---
23 DR. CORRADINI: So something --- I'm 24 sorry, I didn't mean to interrupt you.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
18 MR. HAGAMAN: Yes, go ahead.
1 DR. CORRADINI: Well, something then would 2
be identified that might be considered of low 3
frequency in the PRA but you thought from the HAZOP 4
that it's something important enough that you would 5
want to consider and analyze. Is that what you are 6
trying to get at?
7 MR. HAGAMAN: That could be the case, and 8
it could be the case that we --- and it often is the 9
case for most of our licensing basis events that we 10 understand what they are before the PRA is even 11 conducted. And what we are going to do is make sure 12 that we're going to use the PRA as a final check on 13 our list of licensing basis events to ensure that we 14 did not miss anything and that we categorized 15 everything correctly.
16 MEMBER KIRCHNER: Thank you. Mike 17 Corradini, this is Walt Kirchner. From a designer's 18 standpoint, you do design basis events. I'm curious 19 about, I guess I previously missed the subtlety of 20 licensing basis events versus design basis events.
21 But certainly before you've even done a PRA, you have 22 a conceptual design. You couldn't build the PRA 23 without it. And you identified design basis events 24 that your design--- you know, it's part of the process 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
19 that has to cope with. The PRA then just can expand 1
your thinking and your rigor in systematically looking 2
at what you've created in your design. And perhaps 3
things start systematically, in an iterative design 4
PRA process, eliminating vulnerabilities. But in any 5
event, that would be my take. But is there a specific 6
reason why, Drew, you use --- I guess because this is 7
your NRC submittal eventually that you use the word 8
licensing instead of design basis events.
9 DR. CORRADINI: I guess my thought, Walt, 10 and the reason I asked the question is I was just 11 trying to figure out if they were using something 12 different, which he answered. But the LBEs could be 13 AOOs or could be DBEs depending on frequency. But 14 that would be determined later once they essentially 15 decided what fits, what's in and what's out.
16 MEMBER KIRCHNER: I agree. For me, DBEs 17 are AOOs and Design Basis Accidents, and then beyond 18 that is beyond Design Basis Accidents. But the 19 terminology seems to be morphing somewhat here to 20 licensing basis events. Would that include Beyond 21 Design Basis Events?
22 MR. HAGAMAN: Yes.
23 MEMBER KIRCHNER: Okay.
24 MR. HAGAMAN: So our licensing basis 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
20 events includes AOOs, design basis events, and beyond 1
design basis events. And the design basis event as 2
well. So the LBE is a superset of everything that is 3
in our safety case that we submit for review.
4 MEMBER KIRCHNER: Thank you.
5 MR. HAGAMAN: So just like in the first 6
bullet, we want to be clear that all of our LBEs 7
correspond to sequence families without getting into 8
the weeds of where they first came from originally.
9 We similarly --- when we talk about PRA safety 10 functions --- when we talk about safety functions in 11 the safety case, we don't want to suggest that every 12 safety function was born from the PRA analysis.
13 Because just like the licensing basis events, 14 designers have a conceptual design in their head 15 before we even put pen to paper on the PRA. So we 16 want to make it clear that the safety functions are 17 the safety functions, but they also correspond to PRA 18 safety functions when you are in the PRA context. But 19 we don't like using the phrase 'PRA safety functions' 20 outside of the PRA context.
21 The final Kairos specific implementation 22 bullet has to do with the success criteria for DBA 23 consequence evaluations. So the DBA evaluation model 24 that we'll use for the KP-FHR will provide a bounding 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
21 calculation of those consequences, but they include 1
bounding inputs rather than formal, quantitative 2
combination of uncertainties. Justification that the 3
DBA evaluation models are sufficiently bounding may be 4
based on qualitative arguments in some cases so then 5
direct calculation of 95th percentile figures of 6
merit. In 18-04, the statement was that DBAs are all 7
evaluated on the basis of 95th percentile. And we 8
want to leave the door open to consider alternative 9
means to justify that we have a bounding model. So 10 deviation --- yes, sir, you have a question?
11 DR. CORRADINI: Can you give me an example 12 of this? This one I did not understand. So would a 13 specific example help me?
14 MR. HAGAMAN: Sure. So if we are 15 calculating the release from a particular area of the 16 plant in a DBA basis, rather than choose a 95th 17 percentile leakage rate, we may choose a very, and 18 obviously bounding input, of 100 percent leakage, or 19 a reasonably high leakage rate that is not based on a 20 particular quantile like 95th percentile on the input.
21 Therefore the output of the analysis, to call that a 22 95th percentile consequence metric may not be 23 completely accurate. So we want to say that our DBA 24 evaluations are going to be bounding, but we don't 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
22 want to restrict that statement to a specific 95th 1
percentile a priori.
2 DR. CORRADINI: So let me just say it to 3
you, back at you. Are you saying that in some cases 4
it would be too hard to compute the 95th percentile, 5
and it's easier to basically bound it and just develop 6
a qualitative argument that what you've decided to use 7
is bounding and not try to characterize it beyond 8
that?
9 MR. HAGAMAN: Yes.
10 CHAIRMAN PETTI: I have a question then.
11 You specifically said a DBA here. But as I recall, on 12 the frequency consequence plot, you tend to plot DBEs 13 and put error bars on those. Are you still planning 14 on doing that? And it's only in the DBA consequence 15 where you allow credit for safety related equipment, 16 et cetera?
17 MR. HAGAMAN: Yes, and that's an important 18 distinction. So there are --- as you said, AOOs, 19 DBEs, and BDBEs get evaluated against frequency 20 consequence criteria, and there we do our best 21 estimate of a 95th percentile. However, in the 22 methodology, on the back side of those event sequence 23 families we have deterministic design basis accidents 24 that are derived from the design basis events, and for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
23 those we use more --- something that looks more like 1
a traditional design basis accident analysis where we 2
use deterministic assumptions and deterministic 3
inputs.
4 MEMBER KIRCHNER: You know, for me, Drew, 5
an example, it may not be relevant to you would be 6
Appendix K, which is kind of a bounding deterministic 7
set of criteria rather than a best estimate with some 8
uncertainties associated with it, et cetera. Of 9
course that's not a good analogy here because I don't 10 think that applies to your design, but that would be, 11 for me, for DBAs an example of using a bounding model.
12 MR. HAGAMAN: I agree that that is the 13 spiritual example of what we are talking about when we 14 say design basis accidents. We are talking about a 15 universe of options that includes something like LWRs 16 when they use Appendix K. And we will talk about 17 design basis accident evaluation models in future 18 submittals. So the main purpose of broadening the 19 criteria, or the possible criteria here, is that we 20 can speak more clearly about what our DBA evaluation 21 models should look like in future submittals. We want 22 to create room to do that without giving the 23 impression in this submittal that we are going to 24 calculate specific quantiles.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
24 DR. CORRADINI: But I guess let me ask me 1
ask my question again. Member Petti asked if you were 2
going to do it for the DBEs, but if you're going DBEs, 3
then you'd already have the calculation that told you 4
what your 95th is, and you would then choose to go 5
even further and more conservatively assume 100 6
percent? Or a 99? What I'm still struggling with is, 7
if you did it for one, why not use it for the other?
8 But maybe I misunderstand what your point is.
9 MR. HAGAMAN: That's a good clarifying 10 question. I appreciate the way you put it there. And 11 the answer is: there are advantages to reducing the 12 number of assumptions in the design basis accident 13 evaluation model. As you can imagine, every 14 assumption that goes into that calculation is going to 15 get derived into design criteria for safety related 16 equipment. So if instead of taking 10 probabilistic 17 assumptions, if you could use reasonably bounding 18 conservative assumptions, then there is fewer criteria 19 that need to float down to your safety related 20 equipment in terms design space. So there are 21 advantages to simplifying the design basis accident 22 evaluation model where there is an argument that you 23 are still bounding.
24 DR. CORRADINI: I think I get it. I'm 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
25 still looking for --- maybe this is inappropriate 1
because this is an open session. I'm still looking 2
for a specific example to lead me through this 3
empirically.
4 CHAIRMAN PETTI: Mike, the way I think 5
about it is, if you look at light-water reactors, 6
there is a certain margin. Here the margins are 7
probably larger, and so they are able to be more 8
cavalier for lack of a better word in their DBA 9
consequence calculation, and not have six safety 10 systems having a safety requirement. Whereas I'm just 11 going to calculate it with one safety function 12 operating, and I'm still okay because of all the 13 margin that's there. That's what I think.
14 MEMBER REMPE: This is exactly what GA 15 did. I can remember them coming to a meeting with 16 Fred Sillady talking about this, that it's how you 17 pick the safety related equipment, and then you only 18 rely on the safety related equipment, right?
19 CHAIRMAN PETTI: In DBA space, yes.
20 MEMBER REMPE: Yeah, and so that you don't 21 go and do this 95th percentile and all that for the 22 DBAs.
23 CHAIRMAN PETTI: Right.
24 DR. CORRADINI: But I think --- let me 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
26 press the point, then I'll stop because maybe I'm 1
making too much of this. But in the past examples you 2
guys have, it's a single-failure criteria and I would 3
essentially have three things and I'd only need one to 4
work.
- Here, the single-failure criteria is 5
disappeared so I have a probabilistic criteria, so the 6
95th percentile seems to have to be considered.
7 Again, maybe I need an example that would drive this 8
and I'll just wait and stop at the moment.
9 MEMBER REMPE: So they're, again, for the 10 DBA, you only assume the safety-related systems are 11 working. Which is not how you would do --- Fred used 12 to have a plot and he'd show how the same sequence 13 would be plotted on this frequency-consequence plot 14 and, again if you did the DBE that was in the DBA 15 space, assuming everything worked with the appropriate 16 likelihood of it working with the uncertainty bars.
17 And then he'd also do the DBA for that particular 18 sequence. Does that help at all? If you pull up his 19 old slides, you can see it.
20 DR. CORRADINI: No, I know what you're 21 trying to show me on the plot. I'm trying to 22 understand why not use the information I've got 23 because we're talking about the x-axis not the y-axis.
24 So once I have the x-axis and the dose is going to be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
27 calculated, I have to understand the effectiveness of 1
the safety system that is being used. And the 2
effectiveness is not a single point value, it's a 3
potential range, which allows me then to have a 5th 4
and a 95th. So, once I have it operating, I can 5
assume a bunch of things don't operate, that's fine.
6 But once I assume something operates, I have to assume 7
a performance of it to get a source term.
8 MEMBER REMPE: So what you'd like them to 9
do is if you had three systems, and only one operates, 10 you'd like them to have that range for its operations, 11 but then they might not, in some designs, they might 12 not meet the criteria. And so back in the old days in 13 the gas reactor, that's why we used to do it that way.
14 I don't know about their design if it's got it. But 15 that's --- it was getting close to the boundary is why 16 they used to do it that way in the old days.
17 DR. CORRADINI: I don't want to take any 18 more time. I was looking if I was going to get an 19 example. I'll wait and come back to this when we can 20 do a very specific example on their specific design.
21 MR.
HAGAMAN:
- Okay, so with your 22 permission, we will move on to the next technical 23 area?
24 CHAIRMAN PETTI: Go ahead.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
28 MR. HAGAMAN: So the second of three 1
technical areas --- we're now on slide eight by the 2
way. The second of the three technical areas is the 3
safety classification and performance criteria for 4
structures, systems and components. And from now on, 5
instead of structures, systems and components, I'm 6
just going to say SSCs.
7 A comparison of the table of contents 8
between 18-04 topical report for this section shows 9
that there are only editorial differences to the 10 general outline. Like we saw before where 18-04 11 applies to all advanced non-LWRs, ours is simply just 12 for our technology.
13 There is another editorial change in 14 section 4.4.2 where we deleted the word regulatory 15 from design requirements. This was an effort to clean 16 up the language. We believe that design requirements 17 are more appropriate than regulatory design 18 requirements because they exist in design space and we 19 want to separate the thinking from the actual 20 transition to a regulatory submittal.
21 If we move to the next slide, we can talk 22 about the similarities and any differences.
23 So we are on slide nine right now. And 24 once again there's broad similarities between 18-04 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
29 and our topical report for this methodology. We had 1
the same safety classification approach. We have the 2
same definitions for safety significance and risk 3
significance. And we similarly include in the 4
population of safety-significant SSCs that are 5
required for Defense-in-Depth adequacy. We have the 6
same required functional criteria with the addition of 7
one more, which we'll talk about in the Kairos 8
specific implementations. We have the same process of 9
flowing down design requirements for safety related 10 SSCs. And we have the same evaluation of SSCs that 11 are safety related or non-safety related with special 12 treatment where we measure their performance against 13 frequency-consequence targets. And we have the same 14 special treatment requirements that flow down from 15 safety related to non-safety related with special 16 treatment SSCs.
17 There's two important distinctions ---
18 differences that we want to highlight here that we saw 19 fit for the Kairos specific implementation. The first 20 has to do with the word shall when talking about 21 integrated plant risk targets. NEI 18-04 talks about 22 how the plant risk targets shall not be exceeded. We 23 think it's more important to say the phrase should not 24 be exceeded when talking about integrated plant risk 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
30 targets. Shall is the language of verifiable 1
regulatory compliance, and that doesn't fit 2
necessarily the intent or the technical capability of 3
PRAs, which combine data based on engineering judgment 4
and assessment of uncertainties. We deliberately use 5
the term targets when we are talking about plant risk.
6 To ensure our commitment is clear, we will provide 7
justification that the risk targets are not exceeded, 8
but PRAs cannot possibly do this in any verifiable way 9
in terms of Appendix B quality.
10 The second Kairos specific implementation 11 detail is we added an additional required functional 12 design criterion for our safety related SSCs. The two 13 that are common between 18-04 and our topical report 14 are the criterion first to mitigate DBEs within the FC 15 target, and DBAs within the frequency-consequence 16 limits. The second common criteria is that we're 17 going to prevent high consequence beyond design basis 18 events from exceeding ten to the minus four per year 19 in frequency. And to these two, we added a third one 20 that our --- we have required functional design 21 criteria to shut down the reactor and maintain it in 22 a safe shutdown condition.
23 We've identified that this criterion is 24 part of the 50.2 definition for safety-related 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
31 structures, and we have further identified that the 1
reactivity criterion would like have naturally fallen 2
out of this methodology frequency-consequence process.
3 And we decided to include it for completeness and to 4
maintain consistency with the 50.2 definition so we 5
don't have to take a regulatory exemption from that 6
rule.
7 MEMBER KIRCHNER: Drew, this is Walt 8
Kirchner again. This now is just one member's 9
opinion: I commend you for adding this because that, 10 as you correctly point out, that is part of the 11 safety-related definition. If you were to go forward 12 under 10 CFR 50 or 52, that is a functional 13 requirement as to meet the definition of safety-14 related SSCs. Thank you.
15 MEMBER MARCH-LEUBA: Yeah, let's go back 16 one bullet that replaced shall with should. I almost 17 lost a heartbeat here when --- the honesty of you 18 saying I cannot possibly certify through risk analysis 19 that this thing happens. I have high confidence it 20 does, but it doesn't --- it shall is not achievable.
21 I think this should be engraved on a plaque and put on 22 the wall because this is true and real and honest.
23 This is the first time I heard this said. I want to 24 put you on the record. Okay ---
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
32 MR. KIRCHNER: Jose, I concur as well on 1
that one. As Drew pointed out, there's no way in an 2
Appendix B space with a PRA demonstrate shall.
3 MEMBER MARCH-LEUBA: For the record this 4
is not a Kairos problem, it's a risk analysis problem.
5 MR. KIRCHNER: But these are good insights 6
going forward, I think, as we consider this LMP.
7 MEMBER MARCH-LEUBA: Okay.
8 MR. HAGAMAN: Thank you. Are there any 9
other comments or questions before we move on to the 10 third technical area? Okay. Hearing none, Drew, can 11 we move on to slide 10 please?
12 So the third and final technical area is 13 the evaluation of Defense in-Depth adequacy. So it 14 would be --- the table of contents for this section is 15 long so we split it across two slides. In the first 16 slide you see there is almost identical table of 17 contents between 18-04 and our topical report. I'll 18 highlight the one difference is in section 5.4.
19 Instead of where 18-04 says it is technically 20 inclusive RIPB framework, we simply had an RIPB 21 framework. Again, we are focused only on our 22 technology.
23 The next slide, slide 11, provides the 24 second half of its table of contents. Here there is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
33 a couple of differences. The first example of which 1
is in section 5.7.2. where we have evolved the 2
definition of IDP from 18-04's definition of 3
Integrated Decision-Making Process to an Integrated 4
Decision-Making Panel. I'm going to talk about this 5
more substantively in the next slide. I just wanted 6
to highlight it here because it shows up in the table 7
of contents.
8 The second difference to highlight is 9
section 5.9.3 which the title indicates in 18-04 that 10 the IDP Actions Establish Defense In-Depth Adequacy.
11 In our methodology, however, we make sure that the IDP 12 actions confirm DID adequacy, but we don't want to 13 give the impression that DID adequacy is first 14 established by any IDP action. The IDP doesn't 15 necessarily document the Defense In-Depth baseline.
16 Rather, our panel will ensure that the baseline is 17 documented with adequate completeness.
18 Sections 5.9.5 and 5.9.6 in 18-04 were not 19 copied over into our topical report. They provide 20 helpful information on how you get the baseline 21 evaluation of Defense In-Depth for a vendor that's 22 cycling through design iterations. But we didn't find 23 anything actionable from a regulatory perspective 24 there. So, while it's good information and we're glad 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
34 that it appears in 18-04, we didn't see any purpose in 1
copying it over into our topical report.
2 MEMBER KIRCHNER: So, Drew, this is Walt 3
Kirchner again, interrupting. I kind of, once again, 4
concur with where you are coming from, but it begs the 5
question then, what is the fundamental basis that you 6
are going to use in determining adequate Defense In-7 Depth? What philosophical concept and set of metrics 8
or criteria are you going to use, Kairos. Or maybe 9
this a closed-session question. But I'd be very 10 interested to see --- I would say that a weakness in 11 LMP and 18-04 is it's more process than it is 12 substance.
13 So what substantively are you going to 14 base your confirmation of Defense In-Depth on? Is it 15 the IAEA kind of approach of lines of defense? Or is 16 it something comparable to what is used for --- my 17 colleague, Charles Brown, has been promulgating for 18 quite some time, where one looks at fundamental 19 principles that counter common cause failure kind of 20 issues that are rather unique to digital I&C. So, 21 philosophically, how are you going to address this?
22 MR. HAGAMAN: Thank you. We are going to 23 address Defense In-Depth --- there's basically a 24 three-pronged approach that we are trying to make sure 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
35 we don't lean on any particular element of the safety 1
case to be the primary leg of the stool. We have 2
three elements to our safety case. We have plant 3
capability, where we have our Defense In Depth 4
guidelines around the identification of our design 5
basis accidents and the safety related equipment 6
that's credited in our design basis accidents, and we 7
have very deterministic inputs that come out of that.
8 We have our risk-informed performance-based elements 9
where that's typically where we have our license basis 10 events plotted on an F-C chart and we're making sure 11 that we have all of our licensing basis events are 12 within the targets that we agree upon. And, like you 13 said, there's the IAEA layers of defense, and that 14 framework is actually incorporated into our ---
15 (Audio interference.)
16 CHAIRMAN PETTI: Does anybody hear him? I 17 think we lost him.
18 MEMBER REMPE: I don't hear anything, too.
19 DR. CORRADINI: I thought I was kicked 20 offline. I've lost him.
21 MS. LUI: I think he was disconnected for 22 some reason.
23 CHAIRMAN PETTI: Can somebody from Kairos, 24 who's listening?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
36 MR. PEEBLES: Yes, we're working on it.
1 CHAIRMAN PETTI: Great.
2 DR. CORRADINI: This is the topical area 3
that I am most uncertain as to what is in the NEI 4
document. So, Walt asked the question. I want to 5
hear the answer.
6 MEMBER KIRCHNER: Yeah, pardon my saying 7
it, it's the least --- I was going to say the weakest 8
part. I'll say that it's the least mature and least 9
well tested and proven. It's never going to be proven 10 that you have adequate DID. It's going to be 11 something in the eye of the beholder. But the reason 12 for my question is to
- see, like I
- said, 13 philosophically from a designer's standpoint how 14 you're systematically approaching this particular 15 aspect of the LMP.
16 DR. CORRADINI: Let's wait until he comes 17 back.
18 MR. PEEBLES: Yeah, Jordan should be 19 reconnected.
20 MR. HAGAMAN: Hi. I reconnected. I'm 21 sorry, I was gesturing, and I ended up dropping the 22 call.
23 MR. KIRCHNER: I apologize, Jordan, I 24 thought it was Chris, but it's Jordan. So, thank you.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
37 CHAIRMAN PETTI: You broke up from, you 1
said that you had three legs of the stool. You talked 2
about the first two but you got cut off before the 3
third.
4 MR. HAGAMAN. Right, so the third is the 5
programmatic Defense In Depth which is basically 6
systematically going through and looking at the 7
assumptions from our plant capability Defense In Depth 8
and our risk-informed performance-based evaluations 9
and understanding what were the assumptions underlying 10 those evaluations and making sure that our plant has 11 programmatic characteristics built in to ensure that 12 those assumptions remain true in the life of the 13 plant. So we have, I think, very systematically we go 14 through the plant capability with our deterministic 15 DBAs and our layers of defense. We have risk-informed 16 approach where we let the PRA inform judgment that we 17 are within our frequency-consequence target criteria, 18 and we ensure all of the assumptions from those two 19 evaluations remain true programmatically whether ---
20 in the programs that maintain our SSCs that follow our 21 SSCs through the design process and the sourcing 22 process and inspections and all of that.
23 Does that address your question?
24 CHAIRMAN PETTI: Well, I'm just trying to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
38 understand how it's different than the NEI. Or is it?
1 MR. HAGAMAN: It's --- so this part is 2
exactly the same with the nuance that we are 3
presenting all of these elements together to our 4
integrated decision making panel for the integrated 5
decision making panel to go through and agree that we 6
have checked all of these boxes. So we approach this 7
--- we use the framework to confirm our safety case 8
but not necessarily to establish it. That's the only 9
difference between the methodologies.
10 MEMBER KIRCHNER: Jordan? Again, Walt 11 Kirchner. Who would be on your integrated decision-12 making panel?
13 (No audible response.)
14 MEMBER KIRCHNER: Not by name, obviously, 15 but by ---
16 (Laughter.)
17 MEMBER KIRCHNER: What would be the 18 composition of it? Much like PIRT panels. I'm curious 19 about your approach. Well, I'll jump to what I would 20 like to hear. As someone who is not a Kairos Power 21 person, which is hard to do when you're dealing with 22 proprietary information and so on. But getting 23 someone outside of the cooler or coffee klatsch could 24 be extraordinarily valuable to challenge your 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
39 colleagues when you go through that exercise.
1 DR. CORRADINI: I agree with Dr. Kirchner, 2
Member Kirchner on this. In fact, the panel is what 3
I was going to ask about anyway, about the construct 4
or the constitution of it, so.
5 MR. HAGAMAN: So with regards to the 6
composition, whether it is a mix of internal and 7
external resources, we're not prepared to give an 8
answer to that today. But what we are committed to is 9
ensuring that the panel has sufficient independence 10 and sufficient diversity in technical disciplines and 11 expertise to make judgments. But anything more 12 specific than that on composition, we're going to have 13 to get back to you.
14 MEMBER KIRCHNER: No, this was --- I 15 wasn't looking for an answer, it was a suggestion.
16 Having been in your shoes, one gets to believe what 17 one is doing so strongly, that the outsider's look, 18 certainly at this point in the LMP process, can be 19 invaluable to look for things that you may not have 20 considered and other oversights, and there is good 21 experiential data to back up my point.
22 CHAIRMAN PETTI: Yeah, it's even beyond 23 nuclear. It's in all logic projects. It's logic 24 project group think. There's tons of papers in the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
40 literature on that sort of stuff and how you can get 1
blindsided.
2 MEMBER REMPE: I went back to the Southern 3
pilot study and it looks like at the point it was 4
issued, no one had done anything on Defense In Depth.
5 Have you tried to do this and moved along in this 6
project a bit more to try and see if --- where are 7
you? You said you'd done this pilot with Southern.
8 Had you gotten any further with it?
9 MR. HAGAMAN: We --- so, yes. We went 10 through and we piloted every step of the process with 11 Southern. We don't currently have any other pilots 12 docketed. We haven't performed the formal IDP yet.
13 But I want to observe that when we do get to the point 14 where we're commissioning an IDP, I'll observe that 15 Kairos Power regularly uses external resources in sort 16 of a red-team model whenever we are making important 17 decisions and where we are considering submitting 18 important documents externally. And it's reasonable 19 to assume that we have that tool in our toolbox when 20 we're thinking about IDP. I'm just not prepared in 21 this meeting to commit a specific process or format.
22 MEMBER MARCH-LEUBA: Will this panel be 23 empowered to do the postulated DBAs? Because it is ---
24 when you have the frequency-consequence chart, it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
41 makes very logic. It look really scientific until you 1
realize that it's based on some frequencies calculated 2
by some PRA that doesn't exist. So, the way we had 3
reactors 50 years ago, safer, is by postulating 4
accidents saying, I don't think this accident like a 5
double-ended guillotine break LOCA is going to happen.
6 But let's make sure that if it were to happen, nothing 7
bad happens to the core. So those are the postulated 8
accidents that --- they are not AOOs but you still 9
have to survive. And this panel would be in charge --
10
- I assume this will be the panel that will be in 11 charge of looking for this deterministic accident 12 because --- especially in this revolutionary, with 13 emphasis on the r at the beginning, reactors, we don't 14 have any operating experience. It truly, once you 15 look at what could possibly happen, whether you expect 16 it to happen or not, and see what happens to the core.
17 That's just my comment.
18 MR. HAGAMAN: Thank you. So the panel 19 absolutely is --- the whole purpose of the panel is to 20 introduce engineering judgment and to do a comparison 21 of uncertainties, and yes, to make an evaluation that 22 the design basis accident selection, and the 23 assumptions in design basis accidents are reasonably 24 bounding. And the judgment of the panel could 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
42 certainly be that no, the design basis accident 1
selection is not complete and to identify where that 2
might be --- which areas that might be in. And then 3
the burden will go back to design and analysis 4
iteration to incorporate that feedback and come up 5
with a revised safety case for the IDP to look at 6
again.
7 So, yes, the power does rest in the IDP in 8
that we need the IVP to confirm our safety case or we 9
can't move forward.
10 CHAIRMAN PETTI: So let me just ask a 11 question, more from a design perspective. You know, 12 let's look at redundancy and diversity and 13 independence, and assessing whether or not you've got 14 enough of that, you know, against a certain safety 15 function. It seemed to me that how one evaluates that 16 question is really a function of the technology. So 17 in a light water reactor construct, what might work 18 there, and be optimal there, today, may not be optimal 19 for an advanced reactor where there's no operating 20 experience, or limited operating experience, as I say.
21 There's a lot more uncertainty and so you have to 22 somehow compensate with additional redundancy or 23 additional diversity, and highlight --- to me, that 24 would be highlighted as, look this is what the process 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
43 could do. Is that a fair way to think about how you 1
guys from the design perspective are going to think 2
about these things to compensate for the fact that 3
we've never built one of these types of new machines 4
before?
5 MR. HAGAMAN: Yes, and we expect those 6
judgments to appear both when we're talking about 7
plant capability and dealing with the assumptions 8
there. But we also expect these types of judgments to 9
naturally fall out of the risk-informed process where 10 if we need to use broad uncertainty distributions on 11 individual pieces of knowledge in our PRA model, 12 that'll naturally lend itself to judgments that it's 13 an area where conservatism in margin is needed to 14 compensate for a growing state of knowledge.
15 CHAIRMAN PETTI: But in the end, I mean I 16 sort of agree with that, does that in fact, though, 17 make it difficult to really get the risk insights 18 because you've had to put more margin in, if you will, 19 or compensate for more uncertainty than if you were to 20 go back and redo this ten years after the plant had 21 operated, you might get a different set of risk 22 insights because you've got some experience?
23 MR. HAGAMAN: That could be the case, and 24 it could be the case that future technology iterations 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
44 of the FHR could take advantage of the operating 1
experience from the first plants. And those 2
subsequent nth of a kind plants may have a different 3
safety case than the original one because we have 4
better knowledge and that reflects in margins.
5 CHAIRMAN PETTI: Right.
6 MEMBER KIRCHNER: I'm tempted to say this, 7
David. There is no immaculate conception in advanced 8
reactor designs. You always learn as you design, 9
build, test, and you see that in the generations of 10 improvements that have been made in the existing 11 fleet. I think that's a given. But I think Dave's 12 point more relevant here is just, again, those 13 concepts of diversity, independence, redundancy, and 14 deterministic performance, which I have learned from 15 my colleague Charles Brown very well now, would serve 16 one well in doing this DID confirmation of adequacy, 17 especially for a new design without the large, 18 experimental, or operational base.
19 MEMBER REMPE: So let me try to ask my 20 question a different way. To the level that you did 21 the Defense In Depth adequacy evaluation with the 22 Southern assessment, did you get any insights that fed 23 back to other portions of the LMP?
24 MR. HAGAMAN: Directly, no, but that was 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
45 because of the scope of the evaluation. Because of 1
our state of design at the time, we took a narrow 2
slice approach to piloting each of the steps in the 3
LMP process. So we took a single initiator through a 4
single event tree and a single set of event sequence 5
families to illustrate what the steps might look like 6
for the FHR design. But we would have needed a 7
complete evaluation based on a more complete, more 8
mature design to yield the kind of iterative insights 9
because this is the type of discussion that applies to 10 the whole plant and not individual event sequences and 11 individual SSCs.
12 MEMBER REMPE: Thank you.
13 MEMBER KIRCHNER: Jordan? You made a good 14 point, and I shouldn't let it go uncredited. It 15 applies to the whole plant. One of the things that 16 you have to do now at this phase in this DID adequacy, 17 or whatever, confirmation, whatever the process is 18 called, is look holistically at things, step back and 19 say, okay, we decided that, based on our design, based 20 on our PRA work, et cetera et cetera, these are the 21 categories of scenarios that we have to deal with.
22 But now is the time to step back and say, is there 23 something in the non-safety related SSC category that 24 just could undo everything, all of our best intent and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
46 design? So it really is the point where you step away 1
- from, how should I
say it, the regulatory 2
classifications and look at the whole in a holistic 3
sense. And again, that's where having some outside 4
participation of your choice could be invaluable.
5 MR. HAGAMAN: Thank you. We've recorded 6
the comment.
7 CHAIRMAN PETTI: Keep on going, Jordan.
8 MR. HAGAMAN: So if we can move on to 9
Slide 12.
10 So we've actually touched on most of the 11 content of this slide, so I will review it relatively 12 quickly. We have common methodologies between 18-04 13 and our Topical Report as for defense-in-depth 14 adequacy.
We use the same defense-in-depth 15 philosophy, the same framework as I was mentioning 16 previously split up to Plant Capability elements, 17 Programmatic elements, and Risk-Informed elements.
18 The same 18 task process is used.
19 We evaluate the LBEs against a layers of 20 defense approach or to the IAEA approach. We 21 established the adequacy of programmatic defense-in-22 depth using the same guidelines in 18-04. And we have 23 the same Risk-Informed performance-based evaluations.
24 The Kairos-specific implementations, we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
47 just spent a good deal of discussion talking about how 1
we replaced the integrated decision-making process 2
with an integrated decision-making panel. And I would 3
like to elaborate just a little bit more on that, that 4
when we talk about process, that can tend to get vague 5
or create the potential expectation for documentation 6
and procedures and training associated with individual 7
design decision iterations.
8 And in our methodology, we move away from 9
that process, and we get very specific in talking 10 about we're going to have a panel. The panel is going 11 to meet and perform out discrete, specific activity to 12 review the defense-in-depth adequacy of the design, 13 and we can commit to, in licensing action, we will 14 have this panel. We will have the records and process 15 associated with the panel, any specific documentation 16 on when the panel met, what the information they 17 reviewed was, and what the conclusions were. And this 18 is something specific that we can commit to this 19 information being available for review to support a 20 safety determination.
21 The second Kairos-specific implementation 22 has to do with programmatic focus on event sequence 23 frequency targets rather than SSC reliability targets.
24 Our approach to establishing programmatic defense-in-25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
48 depth focuses on activities that assure that frequency 1
targets are maintained at a sequence level. At our 2
detailed SSC level, however, the focus shifts away 3
from the reliability targets and towards performance-4 based measures such as surveillance frequency and test 5
success rates; things that are actionable, things that 6
are documentable, and performance-based.
7 And like we mentioned on the last slide in 8
this final bullet, there were sections that we decided 9
not to copy over into our Topical Report. It did 10 provide good information for developers but not any 11 actionable information for Kairos as an applicant.
12 And so if we can move on to the final 13 conclusion slide, Slide 13.
14 So just to reiterate, Kairos Power 15 considers the LMP methodologies an adequate means to 16 develop LBE, SSC safety classifications, and to 17 confirm the adequacy of the defense-in-depth 18 attributes of the KP-FHR.
19 Our report details the KP-FHR specific 20 methodologies, which are based on 18-04 and on the Reg 21 Guide approving 18-04, 1.233. And to repeat the ask 22 that Drew gave at the top of the meeting, Kairos Power 23 requests the NRC review and approval of the 24 methodology as an adequate means to define and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
49 evaluate LBEs, classify SSCs, and assess DID adequacy.
1 NRC produced a draft SCR to approve the methodology.
2 That concludes my presentation, and I 3
would entertain any other questions you might have.
4 MEMBER MARCH-LEUBA: Yes, it is Jose. I 5
would like to bring a separate topic. I apologize for 6
bringing it first. Okay, how does functional 7
containment fit into this methodology? Are we going 8
to explicitly model the source term and the radiation 9
or isotope transport with or without a containment or 10 with a functional containment? Can you say something 11 about functional containment?
12 MR. HAGAMAN: Yes. So the functional 13 containment will be evaluated both in our Risk-14 Informed evaluations and in our Deterministic 15 evaluations. So you can expect in the PRA treatment 16 of all the radionuclide retention barriers, whether 17 they're physical or functional. So for the FHR, that 18 includes the characteristics of the TRISO kernels and 19 our salt, specifically in design basis accidents based 20 and in the Risk-Informed space and the PRA, we also 21 take realistic probabilistic assumptions associated 22 with transport to the building and transport from 23 inside the building to the site boundary.
24 MEMBER MARCH-LEUBA: So if I understand 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
50 correctly, all the LBEs will be evaluated with the 1
radioisotopes transport to the boundary and a dose at 2
the boundary, not just figures of merit or something 3
like that. But if we don't have a real containment, 4
and we are relying on a functional containment, my 5
opinion, the LBEs should be analyzed a little further 6
than normal and take it to dose at the boundary.
7 That's my personal opinion. And if your dose at the 8
boundary is ridiculously low, which it's likely to be 9
in this design, fantastic.
10 MR. HAGAMAN: Yes. And this is consistent 11 with the non-LWR PRA standard, which is in its final 12 stages of publication right now. For a non-LWR PRA, 13 we don't have logical surrogates like LWRs do, such as 14 core damage or large early release. So every non-LWR 15 PRA is effectively a Level 3 PRA where we take every 16 event sequence through to release, and we calculate a 17 dose at the boundary like you say.
18 MEMBER MARCH-LEUBA: Is that a regular 19 commitment? I mean, that's what you plan to do, 20 because that's great. This is a very good commitment 21 or standard. It is a very logical way to demonstrate 22 that my plant is safe. I wish, I hope you do it.
23 MEMBER KIRCHNER: Yes. Jose?
24 MEMBER MARCH-LEUBA: And I applaud you.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
51 MEMBER KIRCHNER: Jose, I would submit 1
that, if you're going to do the frequency consequence 2
basis for licensing, you have to do it, as you 3
suggest, for all the licensing basis events, not just 4
a subset. That is almost a -- I would assume, unless 5
I misunderstood the LMP process, that that would be a 6
requirement that they demonstrate that, as you 7
suggest.
8 CHAIRMAN PETTI: That's how I understood 9
it.
10 MEMBER MARCH-LEUBA: I've never seen it in 11 black and white, but, I mean, I will take your word 12 for it. And I think that's what we should do.
13 MR. HAGAMAN: So I'd like to reiterate 14 that LBEs are evaluated on that SC chart, and the x-15 axis is a 30-day total effective dose equivalent at 16 the site boundary. So all of our LBEs need to be 17 evaluated on that basis.
18 MEMBER MARCH-LEUBA: Let me just say one 19 word: wow. I like it.
20 MEMBER KIRCHNER: And, Jordan, then I --
21 this is Walt Kirchner again. Then I would assume you 22 would, in the interim, while 10 CFR 53, quote-unquote, 23 is in rulemaking, in development and rulemaking, that 24 you would fall back on 10 CFR 50 and 52, don't quote 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
52 me on the numbers, 34 dot whatever, for dose at the 1
exclusion area boundary and at the low population 2
zone, if I'm getting this correct, right? I mean, 3
those are some of the anchor points, essentially, in 4
the frequency-consequence curve, at least as presented 5
by the staff.
6 MR. HAGAMAN: Yes, but I want to be 7
specific with my agreement that we use 50.34 criteria 8
when we're talking about our deterministic design 9
basis accidents, which like the PRA, the design -- the 10 deterministic design basis accidents need to be taken 11 all the way to release to look at the dose at the 12 boundary. 50.34 is not directly used when we're 13 talking about DBEs and BDBEs, however. Then we're 14 using the 30-day criteria on the frequency-consequence 15 chart. So there's a subtlety there that I want to 16 make sure is captured for anything else --
17 MEMBER KIRCHNER: Well, what is the 30-18 day, just for the record, could you share what your 19 definition of the 30-day criterion is?
20 MR. HAGAMAN: The frequency-consequence 21 chart has a series of diagonal lines that give, that 22 are based on anchor points. So that's what I'm 23 talking about. That is the basis for the 30-day dose.
24 So we would have to look at the chart to say for an 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
53 event of particular frequency what the appropriate 1
consequence target is.
2 MEMBER KIRCHNER: Okay.
3 CHAIRMAN PETTI: Any other questions, 4
members?
5 DR. SCHULTZ: Dave, this is Steve Schultz.
6 CHAIRMAN PETTI: Hi, Steve.
7 DR. SCHULTZ: Jordan, when you describe 8
the panel, the way the panel would be working, it 9
sounded as if you were describing it as a one-time 10 event that you would contract the panel or red team, 11 however you want to describe it, and there would be an 12 evaluation that would be performed and then completed 13 and documented.
14 It seems to me that the panel activity, 15 given everything that needs to go on, as some of the 16 members have described today, things are bound to come 17 up in the design and licensing process over the course 18 of that activity where the panel might want to -- you 19 might want to have that panel get together on a 20 periodic basis, and I'm not sure what that is; it 21 depends on your pace, of course. But things are going 22 to come up, as Jose mentioned.
23 It is very important that you continue to 24 ask the what-if questions even as you go through the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
54 overall process. You may think you've got a final 1
design, but as you go through the process of design 2
and application, things are going to change, and there 3
is a real benefit of to having a panel that stays 4
organized and continues to ask these questions, both 5
individually and collectively, to make sure that 6
things that you may not think of on day 1 or 10 or 20 7
are identified later on and handled appropriately.
8 MR. HAGAMAN: I agree and, although our 9
specific commitment is to have a panel sign off on our 10 final safety case, we, as a matter of doing the 11 business of iteratively creating a design, we 12 naturally touch on all of these topics when we go 13 through the analysis of the plan. So we regularly 14 exercise the process, and what we want to do is focus 15 on the fact that the commitment is that when we submit 16 a final design and a final supporting safety case for 17 a plant, that you can expect to find available for 18 review in our records at least one IDP evaluation that 19 confirms our safety case. But informally, all of 20 these things get exercised on a regular basis.
21 MEMBER KIRCHNER: That's good. Thank you.
22 CHAIRMAN PETTI: Okay, then. Thank you.
23 And now I guess we will turn to the staff, Stu.
24 MR. MAGRUDER: Thank you, Dr. Petti. Let 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
55 me start sharing my screen here. Okay, hopefully you 1
can see our screen, the NRC slides. Can I confirm 2
that?
3 CHAIRMAN PETTI: Yes.
4 MR. MAGRUDER: Okay, thank you. Thank 5
you. So, again, my name is Stu Magruder. I'm the 6
project manager in NRR for the Kairos Project here, 7
and I just have a couple introductory remarks, and 8
then I will turn it over to Antonio Barrett from NRR 9
also who is the lead reviewer here.
10 Let me say that the draft safety 11 evaluation for this technical Topical Report here was 12 provided to the Subcommittee and to Kairos a couple of 13 weeks ago. It is publicly available now. This is a 14 nonproprietary report, and so our safety evaluation is 15 also nonproprietary, so it's in ADAMS available to the 16 public.
17 As we've discussed earlier, the safety 18 case is largely built on the fact that the staff has 19 endorsed the industry LMP methodology in Reg Guide 20 1.233. Antonio will explain how we did the review and 21 our conclusions of the review.
22 I note that other staff from NRR, 23 particularly Ian Jung, Hanh Phan, and Marty Stutzke, 24 are also on the phone and are available to answer 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
56 questions, particularly if you want to talk about our 1
endorsement of the LMP and the non-LWR PRA standard.
2 So, Antonio, let me turn it over to you, and we will 3
go to Slide 2.
4 MR. BARRETT: All right. Thank you, Stu.
5 This is Antonio Barrett, NRR, Advanced Reactor 6
Technical Branch. In this presentation for the 7
Topical Report review, I'm going to cover the 8
regulatory basis, the review scope and approach, 9
deviations from NEI 18-04, and the conclusions.
10 All right. Stu, can you go to the next 11 slide?
12 All right, for Slide 3, an approved 13 methodology to select the licensing basis events, 14 classify the structure systems and components, and 15 assess defense-in-depth adequacy is used to inform the 16 licensing basis and contents of applications for non-17 light-water reactors. Applicable regulations for 18 contents of applications are 10 CFR 50.34, 52.47, 19 52.79, 52.137, and 52.157.
20 Regulatory Guide 1.233 provides the NR 21 staff guidance on use of a technology-inclusive, risk-22 informed, and performance-based methodology to inform 23 the licensing basis and contents of applications for 24 non-light-water reactors. The Reg Guide endorses NEI 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
57 18-04, Revision 1, with clarifications as one 1
acceptable method for non-light-water reactor 2
designers to use when preparing their applications.
3 Additionally, SECY paper 19-0117, request 4
the Commission to find that the staff's use of the Reg 5
Guide and NEI 18-04 as a reasonable approach to 6
establish key parts of the contents of applications 7
for non-light-water reactors. An SRM to the SECY 8
paper approves the use of the methodology from the Reg 9
Guide in NEI 18-04.
10 All right. Stu, can you go to the next 11 slide?
12 This is Slide 4 for the review scope and 13 approach. The Topical Report methodology is based on 14 the NEI 18-04 document and Reg Guide 1.233. The NEI 15 18-04 methodology has been updated to be specific to 16 KPH -- KP-FHR and there is a small number of minor 17 deviations that don't change the methodology or 18 principles of the 18-04 document.
19 The review scope is focused on the 20 differences between the Topical Report and the NEI 18-21 04 document and confirms that the Topical Report 22 incorporates the clarifications from Reg Guide 1.233.
23 All differences have been reviewed but the focus is 24 mainly on those of some significance.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
58 The presentation covers the most 1
significant ones. While the SE has a couple more 2
minor ones and then there is no mention of some of the 3
more smaller ones that are pretty much editorials, but 4
those were reviewed as well.
5 Stu, can you go to the next slide?
6 For Slide 5, in Section 3, the Topical 7
Report deviates from the NEI document in that it 8
allows for a qualitative arguments instead of 9
quantitative calculations for uncertainty for 10 determining bounding consequences of each design basis 11 event. The methodology commits to justify these 12 qualitative arguments in the future licensing 13 submittals. This is reasonable from a methodology 14 perspective because the staff will have a future 15 opportunity to assess the acceptability of these 16 qualitative arguments, and it is not making a finding 17 from a technical perspective.
18 Can you go to the next slide, Stu?
19 For Slide 6, Topical Report, Section --
20 CHAIRMAN PETTI: Could you go back for a 21 minute? This is Dave.
22 MR. BARRETT: Yes.
23 CHAIRMAN PETTI: This is not exactly what 24 I thought we just heard from Kairos, a qualitative 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
59 argument. This implies to me that there is not going 1
to be a number. There is going to be a number. The 2
technical basis on how bounding it is may be 3
qualitative. Is that what -- instead of a 4
statistical --
5 MR. BARRETT: Right. So instead of, so 6
they're going to make a qualitative argument that 7
could be based off of some other numbers that are 8
bounding, but they're not going to do the 95 percent 9
number in this particular case. And they're going to 10 justify those qualitative arguments on, for a bounding 11 model in a future licensing submittal.
12 CHAIRMAN PETTI: Great, yeah. Okay, now 13 I'm with you. Thanks.
14 MR. BARRETT: Okay. Thank you. Slide 6, 15 Topical Report Section 3.36 describes the process for 16 establishing the risk significance of SSCs. The 17 process is found to be reasonable because it is an 18 element of the integrated Risk-Informed Performance-19 Based approach in the Topical Report and is the same 20 as what's in NEI 18-04.
21 However, currently, there is an industry-22 led PRA standard for a non-light-water reactor which 23 is being developed and expected to be endorsed by the 24 NRC staff through a Reg Guide. This particular 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
60 standard may define risk significance of SSCs 1
differently from what's in the Topical Report.
2 Therefore, Item 2 was added to the Limitations and 3
Conditions sections of the safety evaluation, which 4
states that the applicant should address or justify 5
alternatives to the acceptance criteria in the 6
endorsed standard or Reg Guide related to the 7
determination of risk significance of SSCs as part of 8
implementing the methodology in this topical report.
9 DR. CORRADINI: Can I -- this is 10 Corradini. I guess I'm reading the words and you're 11 implying that the non-LWR, excuse me, the non-LWR PRA 12 standard would have a different definition. Is the 13 definition in a state of flux, and it's still yet to 14 be determined? Can you help me a little bit here?
15 MR. BARRETT: Yeah. So Kairos is actually 16 leading the development of the standard. So it's 17 intended to be consistent with this methodology. So, 18 however, it's not complete yet. It hasn't been 19 endorsed by the staff either.
20 DR. CORRADINI: Okay, all right. Okay, I 21 think I get it. Thank you.
22 MR. BARRETT: This is to just basically 23 make sure that that gets tied into this Topical 24 Report.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
61 DR. CORRADINI: Okay, but the intent is 1
that the definition or the method of determining the 2
SSCs would be the same?
3 MR. BARRETT: That's my understanding.
4 But if they do happen to be different, there has -- it 5
would be expected that they would say something about 6
it.
7 DR. CORRADINI: Okay, thank you.
8 MEMBER KIRCHNER: So, Antonio, this is 9
Walt Kirchner. So risk-significant then they would go 10 with safety-related, non-safety related with special 11 treatment, and just non-safety related. That would be 12 the risk-significance of SSCs?
13 MR. BARRETT: I think this is a little bit 14 different. I think it's just defining -- yeah, so 15 eventually I think you would get there to those but 16 this is going --
17 MEMBER KIRCHNER: Yes.
18 MR. BARRETT: -- about the initial 19 assignment of what the risk significance of a 20 particular SSC is in the PRA.
21 MEMBER KIRCHNER: Yeah. There is PRA-22 speak and then there is regulatory-speak, and I'm just 23 trying to reconcile those.
24 MR. BARRETT: Yes. I think this is PRA-25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
62 speak.
1 MEMBER KIRCHNER: Okay. Thank you.
2 MR. BARRETT: Okay, Stu, can you go to the 3
next slide, unless somebody else has a question?
4 Okay. Thank you.
5 For Slide 7, in Section 4 the Topical 6
Report deviates from NEI 18-04 in that it adds an 7
additional third criterion to the definition for 8
safety-related SSCs. The third criterion is for a set 9
of SSCs performing the reactive shutdown function.
10 The Topical Report states that this is to ensure that 11 the safety-related definition in 10 CFR 50.2 is 12 addressed with the exception of the portion of that 13 Kairos plans to request an exemption for.
14 Adding the criterion is acceptable because 15 it is consistent with regulations, and it has the 16 potential to increase the number of safety-related 17 SSCs. Additionally, Item 1 was added to the 18 Limitations and Conditions section of the safety 19 evaluation, which states that the NRC is not approving 20 any exemptions from NRC regulations and an applicant 21 using the Topical Report will need to address 22 compliance with pertinent regulations and request 23 exemptions as needed.
24 All right, Stu, can you go to the next 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
63 slide?
1 For Slide 8 in Section 5, the Topical 2
Report deviates from NEI 18-04 in that it does not 3
include some general guidance for defense-in-depth 4
layers and source term that do not translate to 5
specific actions or documentation for the process 6
described inside of the NEI document.
7 The methodology commits to justify the 8
mechanistic source term and future licensing 9
submittals, and the defense-in-depth process is 10 already described in other parts of the Topical 11 Report. So this is reasonable from a methodology 12 perspective because the staff will have a future 13 opportunity to assess the acceptability of the 14 mechanistic source term and is not making a finding 15 from a technical perspective.
16 All right, Stu, can you go to the next 17 slide?
18 Slide 9 is the conclusions, and the staff 19 proposes to approve the Topical Report methodology to 20 select the licensing basis events, classify the 21 structures, systems, and components, and assess 22 defense-in-depth adequacy to inform the licensing 23 basis and content of applications, subject to the 24 safety evaluation Limitations and Conditions.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
64 The methodology is essentially the same as 1
what the NRC staff approved for NEI 18-04, Revision 1, 2
and incorporates the applicable clarifications and 3
points of emphasis from Reg Guide 1.233, Revision 0.
4 The differences between the Topical Report and NEI 18-5 04 have been evaluated to be reasonable.
6 And I think that should be the end, and if 7
there is any questions, I'd be happy to answer them.
8 CHAIRMAN PETTI: Members, questions?
9 (No response.)
10 CHAIRMAN PETTI: Okay. Thank you.
11 MR. MAGRUDER: Well, thank you very much, 12 Chairman Petti. This is Stu Magruder again. Let me 13 just kind of conclude by saying that the staff is not 14 specifically asking for a letter on this Topical or 15 safety evaluation, but we would be happy to brief the 16 full committee. And I think tentatively we are on the 17 agenda for the October meeting. So I will leave it to 18 you, Chairman Petti, to decide on that. We will be 19 happy to support that if you would like to do that.
20 I will also note, as we alluded in the 21 discussions here, we have several other Topical 22 Reports from Kairos under review, including the 23 mechanistic source term methodology. I think next up 24 would probably be the fuel performance methodology 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
65 Topical and we, I think we are tentatively scheduled 1
to brief the Subcommittee on that early next year.
2 But we also have other topicals that we just started 3
review on fuel qualification, metallic materials 4
qualification, and the quality assurance program. So 5
we would be happy to come back to the Subcommittee and 6
talk about any of those in the future. So thank you 7
very much.
8 CHAIRMAN PETTI: Great. Well, members, 9
there are a couple of things we need to talk about.
10 First, we should go around and ask members for 11 individual comments, but second, we should talk about 12 whether or not we need to write a letter.
13 I can tell you that we had a phone call 14 with Kairos last week or maybe this Monday. Yes, we 15 had a meeting on Monday. And Dennis was of the 16 opinion that we didn't need a letter. I had a draft 17 letter started before I knew where Dennis was on these 18 things. So I am open to hearing what other members 19 think. So should we just go around --
20 MEMBER REMPE: Dave, should we first just 21 ask for public comments and get that box checked.
22 CHAIRMAN PETTI: Oh, oh, oh, right. Yeah, 23 thanks. I'm assuming, Thomas, the public line is 24 open. Thomas, is the public line open?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
66 MR. DASHIELL: The public line is open for 1
comments.
2 CHAIRMAN PETTI: Okay, anybody on the 3
public line wishing to make a comment, please do so.
4 Okay. I don't hear anything, so I guess there's no 5
comments.
6 So let's go around and see what folks 7
think. Charlie?
8 MEMBER BROWN: Am I first?
9 CHAIRMAN PETTI:
I'm doing it 10 alphabetically. Sorry.
11 MEMBER BROWN: Okay. I thought you were 12 going to get Ron that's why it took me a while to find 13 my button.
14 CHAIRMAN PETTI: He doesn't come up on my 15 list here. He's on a list of the participants. He 16 shows up under R instead of B.
17 MEMBER BROWN: That's all right. I just 18 didn't want him to get mad.
19 CHAIRMAN PETTI: I've been chewed out by 20 professionals.
21 MEMBER BROWN: I'm not chewing. I don't 22 want to get chewed. Let Ron go first. We will do it 23 24 CHAIRMAN PETTI: Okay, Ron. Go first, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
67 please.
1 MEMBER BALLINGER: Geez. Yes, I'm 2
inclined to, since this is the first of the, what may 3
be many non-light-water reactor designs, I'm inclined 4
to think that we should write as many letters as 5
possible. Thank you.
6 CHAIRMAN PETTI: Okay. Charlie.
7 MEMBER BROWN: Well, I'm not in favor of 8
writing as many letters as possible. Okay. I'm kind 9
of in a quandary as to what to do. This was a fairly 10 sparse set of information that was provided, but the 11 staff seems satisfied. It seems like there is more to 12 come. I don't know what this would be a, what are we 13 endorsing? What are we approving, or what are we 14 agreeing within this letter? That's why, that's my 15 question. Just this technical, this Topical Report, 16 period?
17 CHAIRMAN PETTI: Yes. That's what it 18 would be.
19 MEMBER BROWN: Okay, no other, we don't 20 lose the track on anything else?
21 CHAIRMAN PETTI: No. I mean, my personal 22 opinion is the discussions that we had, which are part 23 of this broader discussion that we've been having in 24 other contexts like Part 53 --
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
68 MEMBER BROWN: Yeah.
1 CHAIRMAN PETTI: -- are really where 2
everything is at and whether or not we feel that's 3
important enough to highlight in such a letter; 4
otherwise, we're just, you know, yeah, they're 5
applying LMP. They've made some small changes. We 6
would have to talk about, I think to make the letter 7
have some value, in my opinion, some of the other 8
questions that we -- I've asked about is just things 9
to be cognizant of as one applies the LMP.
10 MEMBER BALLINGER: That's where I come 11 from. I think there's an opportunity in these letters 12 to kind of poke at what we think needs to be discussed 13 in a little bit more detail.
14 CHAIRMAN PETTI: That's where, I was 15 struggling so, you know, I've asked questions about 16 this as part of our Part 53 deliberations and, again, 17 I've been on the Committee long enough to know. I 18 mean, we're iterating the same thing in multiple 19 letters, you know, it might have value. Others may 20 think that it's a little redundant. I don't know.
21 MEMBER BROWN: I missed -- I guess my only 22 point relative to is, was your comment relative to the 23 qualitative aspects, not much quantitative but yet the 24 argument was made that there will be -- I'm not sure 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
69 I'm phrasing this right -- something quantitative 1
later. And I, so I wasn't sure where that's coming 2
from based on the discussion. So that's my only, if 3
we write the letter, we ought to make sure we have 4
some point that we want. That was the only thing that 5
stuck out in the overall discussion to me. I might 6
have missed something else, but if somebody else has 7
a comment, go ahead.
8 CHAIRMAN PETTI: Okay.
9 MEMBER DIMITRIJEVIC: Dave?
10 CHAIRMAN PETTI: Yes, you're next. Yeah.
11 I was just going to call you.
12 MEMBER DIMITRIJEVIC: Okay. So, you know, 13 the, I sort of agree with Dennis because this is not 14 really deviation from NEI 18-04, which is a part of 15 this Reg Guide 1.233 future design, you know 50.53, 16 which we already reviewed. Why would I want that we 17 don't really write a letter, but I really don't have 18 a strong opinion if you find somebody to write the 19 letter, is because they don't have anything specific 20 for them.
21 And we don't really know how their, you 22 know, their PRA is going to look like, how their other 23 design documents are going to look, there is nothing 24 there that we can actually estimate how will this 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
70 application -- there is nothing on application of the 1
NEI except saying we are going to apply.
2 So there is no information related to 3
application itself except it's just, you know, saying 4
okay there is this guide that I'm going to essentially 5
apply with these minor changes. So, in my opinion, I 6
don't think we need to write letter to this. It's, 7
you know, good opportunity for, you know, when we 8
review our, when we continue our future plant design 9
deliberation to keep in mind those changes they find 10 necessary to make and what some of selections that 11 didn't but that's all so -- that's my opinion of the 12 subject.
13 CHAIRMAN PETTI: Jose.
14 MEMBER MARCH-LEUBA: Hold on, it took a 15 while to -- yeah. I'm going to disagree with some of 16 my colleagues. I think we do need a letter. I 17 encourage a letter because this is an Earth-shattering 18 event. It's an incredible deviation from the state-19 of-the-art. This is the first time a plant comes to 20 us and says we are going to use LMP to define our 21 LBEs. Definitely, ACRS should opine on that. And 22 deviations from NEI, I think we should wade into them, 23 but the fact that they use it, as I said, is Earth-24 shattering. It is game-changing. We should not be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
71 silent on it. Thank you.
1 CHAIRMAN PETTI: Okay. Walt, sorry I 2
skipped you. I --
3 MEMBER KIRCHNER: Yes. It is something of 4
a precedent and that may be, assuming that we have 5
something of substance to say in the letter, should be 6
acknowledged. So I'm with, I guess I'm in Jose's 7
camp, but I'm also sympathetic to Vesna's point at 8
this, we don't have a lot of detail. The few changes 9
from the NEI document may or may not be of note.
10 We did have an interesting discussion with 11 the applicant on the defense-in-depth approach. If 12 there is something of merit there, then that probably 13 is worth a comment. And, of course, they scratched my 14 particular itch about shutdown and maintaining 15 shutdown conditions. So from my standpoint, that's a 16 nice precedent to document and share with future 17 applicants, but that's one member's opinion.
18 CHAIRMAN PETTI: Joy.
19 MEMBER REMPE: So before I mention my 20 thoughts on this, I'd also remind everyone of the 21 point I brought up to Jose earlier today about that 22 all we can do as a Subcommittee is make a 23 recommendation for consideration by the full 24 Committee. So this is a little late to say, we're not 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
72 going to write a letter other -- unfortunately, you 1
could really have a very short presentation, but we 2
need to have some sort of process in mind because it's 3
a bit late to decide that we will or won't have a 4
letter as a Subcommittee for what's going to happen at 5
the full Committee meeting, okay? With just --
6 CHAIRMAN PETTI: Our P&P would be too 7
late, right?
8 MEMBER REMPE: Yes. And so, you know, 9
we're kind of trapped by process here, and that's 10 something we can talk about tomorrow at the retreat.
11 But this is a little late in the process to make that 12 decision other than come to the meeting and then 13 decide that we don't want to do a letter. But yet 14 anyway, that's kind of where that's at.
15 With respect to a letter, I wholeheartedly 16 agree unless there is something worthwhile to say, it 17 doesn't mean a lot unless it is a very short letter.
18 Despite the, and so the differences of what they've 19 said about looking at the third critical safety 20 function about make sure you're in a stable, safe 21 shutdown state is great.
22 I note that we didn't discuss that even 23 though they have the first critical safety function 24 about maintaining radioactivity in that report, they 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
73 actually mention that they plan to ask for an 1
exemption for that critical safety function. So we 2
will have to see what that's about in the future. And 3
clearly what's going to be interesting is when they 4
finally pick the licensing basis events, and we start 5
evaluating the application.
6 So, you know again, I would make the 7
letter pretty short, note some differences that we 8
will be very interested in seeing how the defense-in-9 depth thing is being applied ultimately and, you know, 10 things like that, that I wouldn't buy in whole-hog to 11 the report because it's got a lot of open items to be 12 determined.
13 CHAIRMAN PETTI: So let me just ask a 14 process question. The fact that NRC did not ask for 15 a letter, is that a get out of jail free card that we 16 could just decide not to write a letter?
17 MEMBER REMPE: No, we write letters often 18 when we're not asked for one. You know, again, we --
19 CHAIRMAN PETTI: Okay, Dennis is of a 20 different opinion. When we talked about this, he 21 thought we had a way out but --
22 MEMBER REMPE: -- but again, we can't --
23 it doesn't matter whether they ask for one or not.
24 And yeah, that might be a way out, but that way out 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
74 has to be stated at the meeting, you know.
1 MEMBER BROWN: Dave, for your information, 2
I have had subcommittee meetings and I have not 3
written letters on them. So that's --
4 MEMBER REMPE: Right. But we last P&P 5
said we we're going to do a letter, and now we're 6
doing this decision-making at a subcommittee and 7
usually you've got a whole month and there's a bit 8
more time.
9 MEMBER BROWN: I agree with that point, 10 Joy. I'm just saying that we do have subcommittee 11 meetings typically in my circumstances, they've been 12 an early review followed by a subsequent subcommittee 13 meeting before we wrote the letter if we were -- and 14 there have been one two of them when I didn't write a 15 letter all. But the NRC didn't ask for one, and we 16 finished the review. It was kind of pro forma, and we 17 didn't do anything, but that was some years ago.
18 So Dennis is right. We have not always 19 written letters on this meeting, but we did commit to 20 this, and we've got that on the schedule. And to me, 21 the only way we get out of that, in one way, is to 22 reschedule the letter for a later full Committee 23 meeting and then try to refine our differences in a 24 subsequent subcommittee meeting to know where we want 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
75 to go with it because we're putting our Betty Crocker/
1 Good Housekeeping seal of approval on this. And Joy 2
is right, we really didn't go into the -- oh, geez.
3 My brain just fried.
4 MEMBER SUNSERI: This is Matt. I would 5
like to weigh in on the governance of this topic a 6
little bit. First off, I don't think it's, I wouldn't 7
characterize it as late or whatever. I mean, it's 8
pretty typical that we have subcommittee presentations 9
on topics and then the next full Committee meeting we 10 write the letter.
11 And I've also seen it pretty typical in 12 the
- past, as Charlie has mentioned, where a
13 subcommittee has convened and decided not to write a 14 letter. Just because the P&P a couple of months ago 15 without the benefit of any discussion of this made 16 room for a letter on the full Committee agenda, 17 doesn't mean we're obligated to write a letter.
18 So I
think we're at our complete 19 discretion at this Subcommittee. If the Subcommittee 20 agrees that no letter is required, then that report 21 goes forward to the full Committee, of which by the 22 way, everyone is here except for one right now. And 23 that would be perfectly in line with our by-laws, 24 which I've just reviewed quickly, and I don't see 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
76 anything to the contrary there.
1 MEMBER REMPE: Well, we can decide at the 2
full Committee, but I would contend a subcommittee 3
cannot make a decision, even though only one member is 4
missing and that member may not be there at the full 5
Committee. It's just historic that the full Committee 6
makes decisions. Because if you start --
7 MEMBER SUNSERI: Yes.
8 MEMBER REMPE: -- saying we can make that 9
decision --
10 MEMBER SUNSERI: I --
11 MEMBER REMPE: -- at the subcommittee 12 meeting, you might have three members at present or 13 two trying to make the decision.
14 MEMBER SUNSERI: And that's the authority 15 that the full Committee has delegated to the 16 subcommittees.
17 MEMBER RICCARDELLA: I thought the, this 18 is Pete, I thought the process was the subcommittee 19 makes a recommendation to the full Committee as to 20 whether or not a letter was required and the full 21 Committee makes a decision.
22 MEMBER REMPE: That's the way I understand 23 the process.
24 MEMBER RICCARDELLA: And we could do that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
77 at P&P.
1 MEMBER REMPE: Yeah. And, you know, I 2
don't think you can let a subcommittee start making 3
recommendations and assume it's going to be accepted 4
at the full Committee even though it's very likely 5
here.
6 CHAIRMAN PETTI: So Pete, what's your 7
viewpoint on the need for a letter?
8 MEMBER RICCARDELLA: I tend to lean with 9
not thinking one is needed because I don't see where 10 it would have anything substantive to say, and the 11 staff hasn't requested it, but I'll go along with 12 whatever the Committee decides on, whatever the 13 majority of the Committee feels.
14 CHAIRMAN PETTI: Well, I think it's close.
15 It's kind of like, what, there's only eight of us. I 16 think it's 5-3.
17 MEMBER DIMITRIJEVIC: Dave?
18 CHAIRMAN PETTI: Yeah.
19 MEMBER DIMITRIJEVIC: Dave, I was thinking 20 what I forgot to tell you when I was talking that if 21 we didn't write the letter on 123, right, Reg Guide 22 1.223, which endorses 18-04. So what will happen, 23 like technically, what if we don't endorse 18-04 but 24 here we write a letter prematurely? I mean, you know, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
78 that's one of the things that technically one should 1
come after another.
2 CHAIRMAN PETTI: Yeah --
3 MEMBER DIMITRIJEVIC: I don't think we 4
really want to; you know, we had the meetings about 5
the 1.223 Reg Guide, which endorsed NEI. But I don't, 6
I mean, I know that --
7 MEMBER RICCARDELLA: Yes.
8 MEMBER SUNSERI: We did.
9 CHAIRMAN PETTI: Well, maybe we did 10 though. Other members know? Did we write one on 11 1.233?
12 MEMBER REMPE: We wrote in the -- I 13 thought we did on the LMP. I thought it was more on 14 the NEI document rather than the Reg Guide, but I'd 15 have to go back and --
16 MEMBER DIMITRIJEVIC: That I guess --
17 yeah, he may know.
18 MEMBER REMPE: I guess I --
19 MEMBER SUNSERI: Yes. I think we're on 20 record with regards to the LMP.
21 MEMBER BROWN: We did do an LMP letter.
22 That was Dennis' committee --
23 MEMBER SUNSERI: Yes.
24 MEMBER BROWN: -- a while back now.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
79 MEMBER KIRCHNER: Dave? This is Walt.
1 One thought is, you're the chair of this particular 2
project. Since it's kind of a mixed, you're getting 3
a mixed set of opinions, maybe we should defer to your 4
recommendation. This is one of, well we did two 5
previous ones, if in your assessment this is an 6
important thing to document as part of our 7
deliberations on the Kairos eventually, I'm hopeful 8
that we will see an application. And maybe we follow 9
your lead since you already admitted you had a draft 10 and made that much of an effort. If you think this is 11 a good, worthwhile thing to document in the path 12 forward, then I think the Committee would follow your 13 recommendation.
14 MEMBER MARCH-LEUBA: Yeah, I want to put 15 another concept in there. I mean, it is true that 16 those Reg Guides we already have letters and 17 everything, but we just got a couple of things from 18 the applicant that are important.
19 Number one, the only I really care, is 20 they said if we use LMP, we believe we have to use PRA 21 Level 3 for every event. On just that one, deserves 22 a letter and our endorsement and high publicity. You 23 do whatever you want, but the fact that this applicant 24 is at least said verbally, that if I use LMP, I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
80 that the logical progression of that requires me to do 1
a PRA Level 3 for each and every one of my transients, 2
that's big. That's big. All right, over and out.
3 MEMBER DIMITRIJEVIC: Jose, how do you 4
mention they are going to use F-C curve? They need 5
those. They need the frequency and the only Level 3 6
means is, you know, the PRA which calculates dose 7
release. So without Level 3 PRA, you cannot use the 8
F-C curve.
9 MEMBER MARCH-LEUBA: Yeah, yeah. But this 10 is in writing.
11 MEMBER SUNSERI: So Dave, I think, to me, 12 I guess I will weigh on the letter or not letter. I 13 don't think a letter adds much value at this stage 14 because they're just outlining the process that 15 they're going to bring their application forward with.
16 Our detailed safety review will be done on the parts 17 and if there is a significant finding associated with 18 the PRA or the way they encompass safety systems or 19 anything else, we will weigh in at that time based on 20 specific information that is provided to us, not 21 speculation at this time what might or might not be 22 before us.
23 So I would say the fact that they're 24 following the LMP and laid out a road map on how they 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
81 are going to do that, and the staff agrees with that, 1
is sufficient. It should be sufficient for us. And, 2
therefore, I would conclude no letter is necessary.
3 CHAIRMAN PETTI: Derek tells me on the 4
chat that he's got information about the letter we 5
wrote. Derek?
6 MR. WIDMAYER: Yes. The letter that you 7
guys wrote on that Reg Guide, it was an early version 8
of the SECY paper and an early version of the 9
Regulatory Guide. And you did endorse it. You 10 haven't said anything about the final versions, but 11 those were minor edits that were made. And, in fact, 12 Dennis, on his own, decided it wasn't needed to review 13 the final Reg Guide. It was pretty much the same as 14 the draft.
15 MEMBER DIMITRIJEVIC: Okay, well thanks, 16 Derek. That means we will not have a contradiction if 17 we endorse already the Reg Guide. So that means we 18 endorse NEI. Do we endorse F-C curves? That means 19 that --
20 MR. WIDMAYER: Yes, and of course, he 21 said, you know, the proof of the pudding is when the 22 rubber meets the road, so to speak. So but, yes, you 23 said it was a reasonable approach.
24 CHAIRMAN PETTI: So here's what I'm 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
82 thinking, I'm not -- all the issues that we have 1
raised, we've raised in other contexts of Part 53, 2
right, for instance, isn't on the street yet, I don't 3
think, but we went over it at the last meeting. I 4
would like to request a delay of the full Committee 5
meeting to November. In October I will make the 6
recommendation. The Committee can vote. I hope they 7
would take the recommendation of the chair of no 8
letter and then we would not have that meeting in 9
November. That's the only way I can see this staying 10 inside all of these crazy rules.
11 Because what I don't want to do is to drag 12 the staff from Kairos because, you know, a lot of P&Ps 13 at the end of the week, not at the beginning of the 14 week, that sort of stuff. Is that a way around 15 things?
16 MEMBER REMPE: With the current situation, 17 I think it's a great way to go.
18 CHAIRMAN PETTI: Yeah.
19 MEMBER SUNSERI: So, I mean, so it's 20 already on the agenda, right? I mean, if it's already 21 been issued and --
22 MEMBER REMPE: Well, we've regularly said 23 we're going to delay something.
24 MEMBER SUNSERI: I know, but, I mean it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
83 won't even get to the November, right? So if we start 1
the October meeting, we don't have the presentation, 2
we wait 'til Friday on the P&P, Dave makes his 3
presentation, we vote. I mean, it's done, right?
4 MEMBER REMPE: That's what I would think.
5 CHAIRMAN PETTI: Yeah. I just don't want 6
to drag the NRC staff and Kairos to the October 7
meeting.
8 MEMBER REMPE: Are there enough members 9
that you got a majority here, Dave? I kind of lost 10 track, but I would second with what you're saying, but 11 we need to go through and make sure we have a majority 12 if we're going to delay, right?
13 MR. MOORE: This is Scott. May I be 14 recognized, Mr. Chairman, Chairman Petti?
15 CHAIRMAN PETTI: I thought you were 16 talking to Matt.
17 MR. MOORE: No, I'm talking to you, 18 Chairman Petti.
19 CHAIRMAN PETTI: Okay. Yes, go ahead.
20 MR. MOORE: So Vice Chairman Rempe and the 21 others that weighed in, I think are correct that the 22 subcommittee can't make specific decisions in the 23 subcommittee. The by-law actually says that, you 24 know, a subcommittee may also recommend a particular 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
84 course of action to the full Committee.
1 That said, I think that the Committee 2
wants to be careful about considering non-actions.
3 For instance, not doing something as needing votes 4
because the Committee does that kind of thing all the 5
time. I don't think in the past when the Committee 6
has decided not to write letters that those have been 7
going to the Committee for votes.
8 And so I think if needed in cases when the 9
Committee is, well, excuse me, when the subcommittee 10 is split on something or if there is a reason to take 11 it to the full Committee, sure, go to the full 12 Committee. But I think it would be not recommended 13 for every subcommittee to have to go to the full 14 Committee every time it didn't want to write a letter 15 on something.
16 MEMBER REMPE: So the reason I have my 17 opinion is because of the numerous MELLLA+ reviews we 18 did, and we had to be, decide with a lot of 19 forethought, and we could not just make that decision.
20 And it took a lot of support that way to do it.
21 MEMBER KIRCHNER: But, Joy, wait a minute.
22 MEMBER REMPE: So that's -- it's not that 23 background.
24 MEMBER KIRCHNER: -- wait a minute. The 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
85 MELLLA+ things were license amendments and that's a 1
different category altogether. That's a statutory 2
responsibility. There's no proscribed statutory 3
responsibility to review these TRs.
4 MEMBER REMPE: That's true, but then we've 5
had this discussion with Jose on other topics that 6
way, and I think this is something we need to really 7
iron out in the retreat and document so that it's 8
available for all members to see in the by-laws to try 9
and make sure it's well understood.
10 MR. MOORE: Okay.
11 MEMBER MARCH-LEUBA: Yeah, I concur. That 12 we need the rules -- we don't need to modify the by-13 laws but have the rules understood because when I get 14 an email saying this is the list of Topical Reports 15 are available for review and I say this one, this one, 16 and that one. Why do I have to do that? We need to 17 decide on these things and come up with a process.
18 MEMBER KIRCHNER: You're a good judgment, 19 Jose.
20 MEMBER MARCH-LEUBA: I know, I know. I 21 like my judgment.
22 MEMBER KIRCHNER: Just like the Reg 23 Guides.
24 MEMBER MARCH-LEUBA: Yes.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
86 MEMBER KIRCHNER: Just like the Reg 1
Guides.
2 MEMBER MARCH-LEUBA: Yeah.
3 MEMBER KIRCHNER: Because again, it falls 4
in a similar category and then we follow the lead of 5
our lead member on the topic.
6 MEMBER MARCH-LEUBA: My judgment says to 7
have a little guidance and not have one or B or three, 8
and I've been overruled on both. Okay, so let's just 9
10 MEMBER BROWN: I'm going to chime in. I'm 11 going to be consistent somehow here with Scott in that 12 I definitely did make some decisions to not write 13 letters on stuff during a subcommittee meeting along 14 with the members of the subcommittee, but we normally 15 had follow-up meetings scheduled later, generally. I 16 will say that there was one or two times when I 17 didn't, but that was six or seven years ago. So we've 18 been more aggressive in the last few years at making 19 sure we documented, ran it through the, you know, 20 confirm we were going to do a letter early. But I 21 don't think it's against any of our rules for the 22 Subcommittee to decide we're not going to do a letter 23 on this. This is a Topical Report. It's not a 24 statutory item. So Walt's right from that standpoint.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
87 MEMBER REMPE: Actually, MELLLA+ wasn't a 1
statutory item. It was something that the ACRS 2
requested and then we decided to stop.
3 MEMBER BROWN: That was a licensing, the 4
initial parts of it were licensing events.
5 MEMBER REMPE: It's not like a power 6
uprate. It was basically a way of --
7 MEMBER BROWN: Getting more power.
8 MEMBER REMPE: -- controlling the reactor 9
and so it was -- yes, it was a licensing amendment 10 request but, frankly, there are a lot of license 11 amendment requests that we don't write letters on, 12 too. So, again, I just think we need to be careful 13 because I wanted to stop them a long time ago, and we 14 could not do that. Anyway, it's just from what has 15 happened to me in the past. But I don't think the 16 laws, by-laws are very clear about it.
17 CHAIRMAN PETTI: Okay. Well, I'm sure we 18 will discuss this more tomorrow.
19 MEMBER SUNSERI: But, Dave, do you have a 20 clear course of action that you're going to have right 21 now? Do you feel like you got the majority point here 22 to proceed down the path you've described?
23 CHAIRMAN PETTI: Yeah. I think so. So 24 all I need is a majority, right? A simple majority?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
88 MEMBER SUNSERI: Well --
1 MEMBER BROWN: Yes.
2 MEMBER SUNSERI: -- I suppose if you want 3
to call a vote but if you're the decision-maker of the 4
Subcommittee and you just get everybody's input --
5 CHAIRMAN PETTI: Right.
6 MEMBER SUNSERI: -- your counts 10, I 7
don't, you know, it's your call.
8 CHAIRMAN PETTI: Yes. No, I prefer to do 9
what I said I was going to do, which is, I guess, 10 officially delay it, delay the full Committee meeting 11 and then --
12 MEMBER SUNSERI: Yes, and then --
13 CHAIRMAN PETTI: -- then not have it.
14 MEMBER KIRCHNER: Yes. We need to be 15 decisive here in fairness to the staff and the 16 applicant.
17 CHAIRMAN PETTI: Right.
18 MEMBER KIRCHNER: And just say, we're not 19 going to do it in October. And we can deliberate all 20 the other ins and outs after. But, you know, I think 21 that would be a reasonable conclusion to draw at this 22 juncture.
23 CHAIRMAN PETTI: Right. So that's my 24 position. If we don't have to vote, fine.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
89 MEMBER BROWN: I have no problem with 1
that.
2 CHAIRMAN PETTI: Probably back to you 3
then, Mr. Chairman. I guess we're done with the 4
subcommittee meeting.
5 MEMBER SUNSERI: No. You're the chairman.
6 So --
7 CHAIRMAN PETTI: Okay. I'm ready to 8
adjourn unless someone has another discussion point.
9 MEMBER SUNSERI: No, I'm good, Dave.
10 Thanks.
11 MEMBER BROWN: I'm good also, Dave.
12 CHAIRMAN PETTI: Okay.
13 MEMBER REMPE: Thank you.
14 CHAIRMAN PETTI: Then we're done. We will 15 see everybody tomorrow.
16 (Whereupon, the above-entitled matter went 17 off the record at 4:10 p.m.)
18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
KP-NRC-2009-006 707 W Tower Ave Kairos Power LLC 121 W Trade St, Ste 1010 Alameda, CA 94501 www.kairospower.com Charlotte, NC 28202 September 18, 2020 Docket No. 99902069 US Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Kairos Power LLC Presentation Materials for Kairos Power Briefing to the Advisory Committee on Reactor Safeguards on the Risk-Informed Performance-Based Licensing Basis Development Methodology Topical Report This letter transmits presentation materials for the September 24, 2020 briefing for the Advisory Committee for Reactor Safeguards (ACRS), Kairos Power Subcommittee. At the meeting, participants will discuss the Risk-Informed Performance-Based Licensing Basis Development topical report (KP-TR-009-NP) that was submitted to the Nuclear Regulatory Commission for review and approval (ADAMS Accession No. ML20101P623).
provides the non-proprietary presentation materials. Kairos Power authorizes the Nuclear Regulatory Commission to reproduce and distribute the submitted non-proprietary content, as necessary, to support the conduct of their regulatory responsibilities.
If you have any questions or need any additional information, please contact Drew Peebles at peebles@kairospower.com or (704) 275-5388 or Darrell Gardner at gardner@kairospower.com or (704)-
769-1226.
Sincerely, Peter Hastings, PE Vice President, Regulatory Affairs and Quality
Enclosures:
- 1) Presentation Materials for the September 24, 2020 ACRS Briefing (non-proprietary) xc (w/enclosure):
Benjamin Beasley, Chief, Advanced Reactor Licensing Branch Stewart Magruder, Project Manager, Advanced Reactor Licensing Branch Weidong Wang, Senior Staff Engineer, Advisory Committee for Reactor Safeguards
Presentation Materials for the September 24, 2020 ACRS Briefing (non-proprietary)
SEPTEMBER 24, 2020 RISK-INFORMED PERFORMANCE-BASED LICENSING BASIS DEVELOPMENT METHODOLOGY ACRS SUBCOMMITTEE MEETING Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Kairos Powers mission is to enable the worlds transition to clean energy, with the ultimate goal of dramatically improving peoples quality of life while protecting the environment.
Agenda
- Introductions and Opening Remarks
- Background of content in Kairos Powers LMP Topical Report
- Comparison of NEI 18-04 and KP-TR-009-NP 3
Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
=
Background===
- NEI Papers on LBE, PRA, SSC safety classification, and DID adequacy Reviewed by ACRS Input to an integrated guidance document
- NEI 18-04 Integrates the guidance from the NEI papers into a document for NRC endorsement Reviewed by ACRS NRC RG 1.233 endorses guidance in NEI 18-04
- Kairos Power Topical Report is based on NEI 18-04 Same fundamental methodology Minor changes/departures
- Kairos Power requested NRC review and approval of the methodology as an adequate means to define and evaluate LBEs, classify SSCs, and assess DID adequacy for KP-FHR technology. The NRC has produced a draft SER to approve this methodology.
4 Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Comparison of NEI 18-04 and KP-TR-009-NP
- The Kairos Power topical report (KP-TR-009-NP) replicates the methodology from NEI 18-04 with minor changes to the content.
- This presentation will compare and contrast the substantive differences between the reports.
- Editorial changes are excluded from this comparison, including:
Re-formatting Identifying language that indicates Kairos Power is implementing methodology Grammar/syntax corrections Style choices (replace modules with units, replace should be with is or are) 5 Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 3 Selection of Licensing Basis Events
- NEI 18-04, Rev. 1
- 3.1 Licensing Basis Event Definitions
- 3.2 Advanced Non-LWR LBE Selection Approach 3.2.1 Frequency-Consequence Evaluation Criteria 3.2.2 LBE Selection Process 3.2.3 Evolution of LBEs Through Design and Licensing Stages
- 3.3 Role of the PRA in LBE Selection 3.3.1 Use of PRA in LBE Selection Process 3.3.2 Non-LWR PRA Scope for LBE Selection 3.3.3 PRA Scope Adequacy 3.3.4 PRA Safety Functions 3.3.5 Selection of Risk Metrics for PRA Model Development 3.3.6 Contributors to Risk and Risk Importance Measures 6
- KP-TR-009-NP, Rev. 1
- 3.1 Licensing Basis Event Definitions
- 3.2 LBE Selection Approach 3.2.1 Frequency-Consequence Evaluation Criteria 3.2.2 LBE Selection Process 3.2.3 Evolution of LBEs Through Design Stages
- 3.3 Role of the PRA in LBE Selection 3.3.1 Use of PRA in LBE Selection Process 3.3.2 PRA Scope for LBE Selection 3.3.3 PRA Scope Adequacy 3.3.4 Safety Functions 3.3.5 Risk Metrics for PRA Model Development 3.3.6 Contributors to Risk and Risk Importance Measures Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 3 Comparison of NEI 18-04 and KP-TR-009-NP
- Similarities Definitions for AOOs, DBEs, BDBEs, DBAs Definition of the Frequency-Consequence target criteria Use of PRA in LBE selection to develop a comprehensive set of initiating events and event sequences PRA scope addresses spectrum of internal events and external hazards Reactor safety functions defined to correspond to functions modeled in the PRA Overall plant risk metrics defined and risk-significance evaluations performed Kairos importance measure selected from the list of possible measures given in NEI 18-04
- Kairos-specific implementation Replace The LBEs identified in the PRA with The LBEs corresponding to event sequence families in the PRA Replace PRA Safety Functions with Safety Functions DBA consequences to be calculated using sufficiently bounding models that may not include direct 95th percentile calculation 7
Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 4 Safety Class and Performance Criteria for SSCs
- NEI 18-04, Rev. 1
- 4.1 SSC Safety Classification Approach for Advanced Non-LWRs
- 4.2 Definition of Safety-Significant and Risk-Significant SSCs 4.2.1 Safety-Significant SSCs 4.2.2 Risk-Significant SSCs
- 4.3 SSCs Required for Defense-in-Depth Adequacy
- 4.4 Development of SSC Design and Performance Requirements 4.4.1 Required Functional Design Criteria for Safety-Related SSCs 4.4.2 Regulatory Design Requirements for Safety-Related SSCs 4.4.3 Evaluation of SSC Performance Against Design Requirements 4.4.4 Barrier Design Requirements 4.4.5 Special Treatment Requirements for SSCs 8
- KP-TR-009-NP, Rev. 1
- 4.1 SSC Safety Classification Approach
- 4.2 Definition of Safety-Significant and Risk-Significant SSCs 4.2.1 Safety-Significant SSCs 4.2.2 Risk-Significant SSCs
- 4.3 SSCs Required for Defense-in-Depth Adequacy
- 4.4 Development of SSC Design and Performance Requirements 4.4.1 Required Functional Design Criteria for Safety-Related SSCs 4.4.2 Design Requirements for Safety-Related SSCs 4.4.3 Evaluation of SSC Performance Against Design Requirements 4.4.4 Barrier Design Requirements 4.4.5 Special Treatment Requirements for SSCs Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 4 Comparison of NEI 18-04 and KP-TR-009-NP
- Similarities SSC safety classification approach Definitions of safety-significant and risk-significant SSCs Safety-significance of SSCs required for Defense-in-Depth adequacy Required functional design criteria for safety-related SSCs includes mitigating DBEs and DBAs, and preventing high-consequence BDBEs Design requirements established for safety-related SSCs fulfilling Required Safety Functions Evaluation of safety-related and NSRST SSC performance against Frequency-Consequence targets Radionuclide retention barriers have design criteria derived from evaluation of LBEs against F-C Targets and RFDCs Special treatment requirements added for safety-related and NSRST SSCs
- Kairos-specific implementation Replace shall not exceed with should not exceed for integrated plant risk targets Additional required functional design criterion included for shutting down the reactor and maintaining safe shutdown 9
Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 5 Evaluation of DID Adequacy (1 of 2)
- NEI 18-04, Rev. 1
- 5.1 Defense-in-Depth Philosophy
- 5.2 Framework for Establishing Defense-in-Depth Adequacy
- 5.3 Integrated Framework for Incorporation and Evaluation of DID
- 5.4 How Major Elements of the TI-RIPB Framework are Employed to Establish DID Adequacy
- 5.5 RIPB Compensatory Action Selection and Sufficiency
- 5.6 Establishing the Adequacy of Plant Capability DID 5.6.1 Guidelines for Plant Capability DID Adequacy 5.6.2 DID Guidelines for Defining Safety-Significant SSCs 5.6.3 DID Attributes to Achieve Plant Capability DID Adequacy 10
- KP-TR-009-NP, Rev. 1
- 5.1 Defense-in-Depth Philosophy
- 5.2 Framework for Establishing Defense-in-Depth Adequacy
- 5.3 Integrated Framework for Incorporation and Evaluation of DID
- 5.5 RIPB Compensatory Action Selection and Sufficiency
- 5.6 Establishing the Adequacy of Plant Capability DID 5.6.1 Guidelines for Plant Capability DID Adequacy 5.6.2 DID Guidelines for Defining Safety-Significant SSCs 5.6.3 DID Attributes to Achieve Plant Capability DID Adequacy Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 5 Evaluation of DID Adequacy (2 of 2)
- NEI 18-04, Rev. 1
- 5.7 Evaluation of LBEs Against Layers of Defense 5.7.1 Evaluation of LBE and Plant Risk Margins 5.7.2 Integrated Decision-Making Process Focus in LBE Review
- 5.8 Establishing the Adequacy of Programmatic DID 5.8.1 Guidelines for Programmatic DID Adequacy 5.8.2 Application of Programmatic DID Guidelines
- 5.9 Risk-Informed and Performance-Based Evaluation of DID Adequacy 5.
9.1 Purpose and Scope
of Integrated Decision-Making Process 5.9.2 Risk-Informed and Performance-Based Decision Making 5.9.3 IDP Actions to Establish DID Adequacy 5.9.4 IDP Considerations in the Evaluation of DID Adequacy 5.9.5 Baseline Evaluation of Defense-in-Depth 5.9.6 Considerations in Documenting Evaluation of Plant Capability and Programmatic DID 5.9.7 Evaluation of Changes to Defense-in-Depth 11
- KP-TR-009-NP, Rev. 1
- 5.7 Evaluation of LBEs Against Layers of Defense 5.7.1 Evaluation of LBE and Plant Risk Margins 5.7.2 Integrated Decision-Making Panel Focus in LBE Review
- 5.8 Establishing the Adequacy of Programmatic DID 5.8.1 Guidelines for Programmatic DID Adequacy 5.8.2 Application of Programmatic DID Guidelines
- 5.9 Risk-Informed and Performance-Based Evaluation of DID Adequacy 5.
9.1 Purpose and Scope
of Integrated Decision-Making Panel 5.9.2 Risk-Informed and Performance-Based Decision Making 5.9.3 IDP Actions to Confirm DID Adequacy 5.9.4 Evaluation of Changes to Defense-in-Depth Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Section 5 Comparison of NEI 18-04 and KP-TR-009-NP
- Similarities Defense-in-depth philosophy Framework for establishing DID adequacy includes Plant Capability, Programmatic, and Risk-Informed elements 18 tasks in an integrated framework for information of evaluation of defense-in-depth Approach to establishing the adequacy of plant capability DID using the same guidelines Evaluation of LBEs against layers of defense Establishing adequacy of programmatic DID using the same guidelines Risk-informed, performance-based evaluation of DID adequacy using the IDP
- Kairos-specific implementations Replace Integrated Decision-Making Process with Integrated Decision-Making Panel Programmatic focus on event sequence frequency targets rather than SSC reliability targets (at the SSC level, focus on performance-based measures)
Section 5.9.5 and 5.9.6 in NEI 18-04 provided helpful information for developers on internal baselines and documentation, but these sections were relevant to the topical report 12 Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Conclusions
- Kairos Power considers the Licensing Modernization Project methodologies as an adequate means to develop Licensing Basis Events, SSC safety classifications, and to confirm the adequacy of the defense-in-depth attributes of the KP-FHR.
- The report details the KP-FHR methodologies, which are based on the methodologies presented in NEI 18-04 and RG 1.233
- Kairos Power requested NRC review and approval of the methodology as an adequate means to define and evaluate LBEs, classify SSCs, and assess DID adequacy for KP-FHR technology. The NRC has produced a draft SER to approve this methodology.
13 Copyright © 2020 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Questions
Presentation to the ACRS Kairos Power Subcommittee Staff Review of Kairos Topical Reports KP-TR-009, REV 1, KP-FHR Risk-Informed Performance-Based Licensing Basis Development Methodology Presenters:
Stu Magruder - Project Manager, Office of Nuclear Reactor Regulation (NRR)
Antonio Barrett - Reactor Systems Engineer, NRR Reviewers:
Antonio Barrett - Reactor Systems Engineer, NRR Ian Jung - Senior Reliability and Risk Analyst, NRR September 24, 2020 (Open Session) 1
KP-FHR Risk-Informed Performance-Based Licensing Basis Development Methodology Review Overview
- Regulatory Basis
- Review scope and approach
- Deviations from NEI 18-04
- Conclusions 2
Regulatory Basis An approved methodology to select the licensing basis events, classify the structures, systems, and components, and assess defense-in-depth adequacy is used to inform the licensing basis and content of applications for non-light water reactors (non-LWRs).
Applicable regulations:
- 10 CFR 50.34, 10 CFR 52.47, 10 CFR 52.79, 10 CFR 52.137, and 10 CFR 52.157 "Contents of Applications" require a safety analysis and an evaluation of the safety features and barriers to a radioactive release to be included in a preliminary or final safety analysis report.
Regulatory Guide 1.233 provides the NRC staffs guidance on using a technology-inclusive, risk-informed, and performance-based (TI-RIPB) methodology to inform the licensing basis and content of applications for non-LWRs. It endorses, with clarifications, NEI 18-04, Revision 1, as one acceptable method for non-LWR designers to use when carrying out these activities and preparing their applications. (Regulatory Guide 1.233 is the finalized version of Draft Regulatory Guide 1353) 3
Review Scope and Approach Topical Report (TR) Methodology Basis
- Based on NEI 18-04 and RG 1.233 (DG-1353)
- Customized version of the technology-inclusive NEI 18-04 methodology updated to be specific to the KP-FHR technology
- Deviates from NEI 18-04 with a limited number of minor differences that do not alter the principles and methodology of NEI 18-04 and RG 1.233 (DG-1353)
Deviations from NEI 18-04
- Review scope narrowed to assessing the differences between the TR and NEI 18-04 and confirming that the TR incorporates the applicable clarifications identified in RG 1.233
- All the differences reviewed but primarily focused on those considered to be of some significance 4
Deviations from NEI 18-04 TR Section 3
- In describing Task 7a of Figure 3.2 the TR deviates from NEI 18-04 in that it allows for the use of qualitative arguments instead of quantitative calculation of uncertainty for determining the bounding consequences of each design basis accident. The TR methodology commits to justify that the design basis accident evaluation models are sufficiently bounding using future licensing submittals.
- This is reasonable from a methodology perspective because the staff will have a future opportunity to assess the acceptability of any qualitative arguments and does not make a finding on the acceptability of potential future qualitative arguments from a technical perspective.
5
Deviations from NEI 18-04 cont.
TR Section 3
- TR Section 3.3.6 describes the process for establishing the risk significance of SSCs.
The process is reasonable because it is an element of the integrated RIPB approach in the TR and is the same as NEI 18-04.
- Currently an industry led PRA standard for non-LWRs is being developed which is expected to be endorsed by the NRC staff via a Regulatory Guide. The standard may define risk significance of SSCs differently from the TR.
- Item 2 of the Limitations and Conditions section of the safety evaluation states the applicant should address, or justify alternatives to, the acceptance criteria in the Regulatory Guide and endorsed PRA standard related to the determination of risk significance of SSCs as a part of implementing the methodology in this TR.
6
Deviations from NEI 18-04 cont.
TR Section 4
- The first two criteria used as the definition for safety-rated SSCs in the TR are the same as those in NEI 18-04. The TR adds a third criterion for a set of SSCs performing reactor shutdown function. The TR states that the addition is to ensure that the definition in 10 CFR 50.2, Definitions, is addressed with the exception of the portion of this definition for which Kairos plans to request an exemption.
- Adding the third criterion is acceptable since the prescriptive criterion is consistent with the regulations and has the potential to increase the number of safety-related SSCs beyond those identified by the two other criteria.
- Item 1 of the Limitations and Conditions section of the safety evaluation states that the NRC is not approving any exemptions from NRC regulations, and an applicant using the TR will need to address compliance with pertinent regulations and request exemptions as needed.
7
Deviations from NEI 18-04 cont.
TR Section 5
- TR Section 5.7 does not include general guidance for defense in depth layers and source term that do not translate to specific actions or documentation for the process described in NEI 18-04. The TR commits to justify the mechanistic source term approach using future licensing submittals.
- This is reasonable from a methodology perspective because the staff will have a future opportunity to assess the acceptability of the mechanistic source term approach and does not make a finding on the acceptability of the mechanistic source term approach from a technical perspective.
8
Conclusions The NRC staff proposes to approve the KP-TR-009 topical report methodology to select the licensing basis events, classify the structures, systems, and components, and assess defense-in-depth adequacy to inform the licensing basis and content of applications, subject to the safety evaluation Limitations and Conditions.
- The methodology is essentially the same as NRC staff approved NEI 18-04, Revision 1, and incorporates the applicable clarifications and points of emphasis from DG-1353, which has been finalized and issued as Regulatory Guide 1.233, Revision 0
- The differences between the TR and NEI 18-04 have been evaluated to be reasonable 9
Backup Slides 10
Limitations and Conditions
- 1. (Section 3.1) This SE does not approve any exemptions from NRC regulations, and an applicant using this TR will need to address compliance with pertinent regulations and request exemptions as needed.
- 2. (Section 3.3.6) The JCNRM of the ANS/ASME is developing a PRA standard for non-LWRs. If the NRC staff concludes that the ANS/ASME PRA standard is acceptable, the staff expects to endorse the standard via a Regulatory Guide. If the Regulatory Guide is issued 6 months before submission of the licensing application, the applicant should address, or justify alternatives to, the acceptance criteria in the Regulatory Guide and endorsed PRA standard related to the determination of risk significance of SSCs as a part of implementing the methodology in this TR.
11
Safety-Related SSC Criteria NEI 18-04 and TR Criteria
- Mitigate DBE within the F-C Target and DBAs within 10 CFR 50.34 dose limits
- Prevent high-consequence BDBEs (those with doses exceeding 10 CFR 50.34 dose limits) from exceeding 10E-4/plant year in frequency and thereby migrating into the DBE region of the F-C evaluation
- Shut down the reactor and maintain it in a safe shutdown condition 10 CFR 50.2
- The integrity of the reactor coolant pressure boundary
- The capability to shut down the reactor and maintain it in a safe shutdown condition
- The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the applicable guideline exposures set forth in § 50.34(a)(1) or § 100.11 of this chapter 12