ML21060B342
| ML21060B342 | |
| Person / Time | |
|---|---|
| Issue date: | 02/02/2021 |
| From: | Derek Widmayer Advisory Committee on Reactor Safeguards |
| To: | |
| Widmayer, D, ACRS | |
| References | |
| NRC-1368 | |
| Download: ML21060B342 (114) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Future Plant Designs Subcommittee Docket Number: (n/a)
Location: teleconference Date: Tuesday, February 2, 2021 Work Order No.: NRC-1368 Pages 1-71 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
1 1
2 3
4 DISCLAIMER 5
6 7 UNITED STATES NUCLEAR REGULATORY COMMISSIONS 8 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 9
10 11 The contents of this transcript of the 12 proceeding of the United States Nuclear Regulatory 13 Commission Advisory Committee on Reactor Safeguards, 14 as reported herein, is a record of the discussions 15 recorded at the meeting.
16 17 This transcript has not been reviewed, 18 corrected, and edited, and it may contain 19 inaccuracies.
20 21 22 23 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 UNITED STATES OF AMERICA 2 NUCLEAR REGULATORY COMMISSION 3 + + + + +
4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5 (ACRS) 6 + + + + +
7 FUTURE PLANT DESIGNS SUBCOMMITTEE 8 + + + + +
9 TUESDAY 10 FEBRUARY 2, 2021 11 + + + + +
12 The Subcommittee met via Teleconference, 13 at 2:00 p.m. EST, David Petti, Chairman, presiding.
14 15 COMMITTEE MEMBERS:
16 DAVID A. PETTI, Chairman 17 RONALD G. BALLINGER, Member 18 CHARLES H. BROWN, JR. Member 19 VESNA B. DIMITRIJEVIC, Member 20 WALTER L. KIRCHNER, Member 21 JOSE MARCH-LEUBA, Member 22 JOY L. REMPE, Member 23 MATTHEW W. SUNSERI, Member 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 1 ACRS CONSULTANTS:
2 MICHAEL CORRADINI 3 STEPHEN SCHULTZ 4
5 DESIGNATED FEDERAL OFFICIAL:
6 DEREK WIDMAYER 7
8 9
10 11 12 13 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
3 1 C-O-N-T-E-N-T-S 2 PAGE 3 Opening Remarks 4 by Dr. David Petti, ACRS . . . . . . . . . 4 5 Staff Introduction 6 by Michelle Hayes, NRR . . . . . . . . . . 6 7 Draft Staff White Paper: Fuel Qualification 8 for Advanced Reactors 9 by Tim Drzewiecki, NRR . . . . . . . . . . 7 10 Adjourn . . . . . . . . . . . . . . . . . . . . . 71 11 12 13 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 1 P R O C E E D I N G S 2 (2:00 p.m.)
3 CHAIRMAN PETTI: Good afternoon. The 4 meeting will now come to order. This is a meeting of 5 the Advisory Committee on Reactor Safeguards 6 Subcommittee on Future Plant Designs.
7 I am David Petti, a Member of the 8 Subcommittee and I'm chairing this meeting at the 9 request of the Subcommittee Chairman, Dennis Bley.
10 ACRS Members in attendance are Charles Brown; Jose 11 March-Leuba; Walt Kirchner; Mike Corradini, 12 consultant; Joy Rempe; Ron Ballinger; Matt Sunseri and 13 Vesna Dimitrijevic.
14 Derek Widmayer of the ACRS staff is the 15 designated federal official for this meeting and Kent 16 Howard of the ACRS staff is the backup. The purpose 17 of today's meeting is to discuss the draft staff White 18 Paper entitled Fuel Qualification for Advanced 19 Reactors.
20 The Subcommittee will gather information, 21 analyze relevant issues and facts and formulate 22 proposed positions and actions as appropriate. The 23 staff's current plan is to evolve this report into a 24 NUREG document and publish it for public comment.
25 The draft final NUREG with public comments 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 1 addressed will be presented to the ACRS full 2 committee, which is currently scheduled for the 3 September meeting.
4 The ACRS was established by statute and is 5 governed by the Federal Advisory Committee Act, FACA.
6 Therefore, the Committee can only speak through its 7 published letter reports.
8 We hold meetings to gather information and 9 perform preparatory work that will support our 10 deliberations at a full committee meeting. The rules 11 for participation in all ACRS meetings, including 12 today's, were announced in the Federal Register on 13 June 13, 2019.
14 The ACRS section of the U.S. NRC public 15 website provides our charter, bylaws, agendas, letter 16 reports and full transcripts of all full and 17 Subcommittee meetings, including slide presentations.
18 The meeting notice and agenda for this 19 meeting were posted on that website. As stated in the 20 Federal Register notice and in the public meeting 21 notice posted to the website, members of the public 22 who desire to provide written or oral input to the 23 Subcommittee may do so and should contact the 24 designated federal official five days prior to the 25 meeting as practicable.
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 1 Today's meeting is open to public 2 attendance and we have received no written statements 3 or requests to make an oral statement. We have also 4 set aside ten minutes in the agenda for spontaneous 5 comments from members of the public attending or 6 listening to our meetings.
7 Due to the COVID pandemic, today's meeting 8 is held -- being held over Microsoft Teams for ACRS 9 and NRC staff attendees. There is also a telephone 10 bridge line allowing participation of the public over 11 the phone.
12 A transcript of today's meeting is being 13 kept. Therefore, we request that meeting participants 14 on the bridge line identify themselves when they are 15 asked to speak and to speak with sufficient clarity 16 and volume so that they can be readily heard.
17 At this time I ask that attendees on Teams 18 and on the bridge line keep their devices on mute to 19 minimize disruptions and only unmute when speaking.
20 We'll now proceed with the meeting and I call on 21 Michelle Hayes, Chief of the Advanced Reactor 22 Technical Branch, NRR to make introductory remarks.
23 MS. HAYES: Thank you. So, I'm Michelle 24 Hayes. I'm excited about today's meeting on the Fuel 25 Qualification for Advanced Reactors because I'm a big 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 1 fan of this White Paper.
2 It's the first step to closing one of the 3 gaps in our advanced reactor guidance and the document 4 itself embodies our vision for what advanced reactor 5 guidance should be.
6 It includes innovative top down 7 methodology with a well-defined nexus to safety, it's 8 technology neutral, it clearly identifies NRC 9 expectations, and incorporates feedback from internal, 10 external and international stakeholders.
11 We're looking forward to getting ACRS' 12 feedback today. Dr. Tim Drzewiecki has been a driving 13 force behind this paper and he'll be giving today's 14 presentation. So, Tim, take it away.
15 MR. DRZEWIECKI: Thanks, Michelle. Okay, 16 so, yes. So again, yes, this presentation is based on 17 the current draft of the White Paper and will be 18 converted into a NUREG as was stated.
19 So, if I could have the next slide, 20 please. Okay, so as far as -- well, I'll talk about 21 -- first I'll go into, you know, what has happened in 22 the past to kind of bring us up to this point, how we 23 started this work and what kind of drove some of the 24 timeline to get it done, when it was done as well as 25 I'll highlight -- there is a lot of activity also 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 1 going on in the area of fuel qualification besides 2 this.
3 And I'm going to highlight some of the 4 stuff that we're doing there. Then I'll go into --
5 try and give a high level view of what this paper is 6 in terms of its scope, how we came up with the 7 definition of what fuel qualification is, talk about 8 what I mean by an assessment framework, which is a top 9 down approach. Then I'll walk through the framework 10 itself and then just kind of highlight what our next 11 steps are.
12 Can I have the next slide, please? This 13 is trying to give, you know, some of the landscape.
14 And I'm going to work from left to the right.
15 Starting off with advanced reactor stakeholders.
16 Going back a couple years, you know, we 17 knew that there was going to be some work coming in 18 the door that was going to be, you know, having staff 19 look at things, you know, new fuel types or concepts 20 or things that were not like light-water reactor fuel 21 that we had guidance for.
22 And so, we weren't sure how we would do 23 some of these reviews. And so, we tried to give a, 24 you know, a leg up on that and began thinking about 25 that.
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 1 Also, we are involved in NEA, Nuclear 2 Energy Agency. There is a working group there that's 3 a working group on the safety of advanced reactors 4 where we have lots of foreign regulators.
5 They saw similar issues and we thought 6 that this was a topic that we could work on and we 7 began working on a paper through that working group.
8 So, this draft White Paper that you see 9 here, it's got a sister paper and it's actually gone 10 up and it's been approved by CNRA and that should be 11 published pretty soon.
12 Something else that we've seen on the 13 horizon is this concept of accelerated fuel 14 qualification. I'll be referring to it as AFQ several 15 times in this presentation.
16 I highlighted on the slide use of advanced 17 mod-sim. I should also state that it also includes 18 things like, you know, modern or more recent test 19 techniques, things like Fission Accelerated Steady-20 state Testing meaning fuel and things like that, 21 things to speed up some of the test process.
22 So, it's not just simulation. But it does 23 rely a lot on simulation. And I'll have a slide on 24 this actually later.
25 But this is a theme which we wanted to 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 1 have incorporated into this paper so that we, you 2 know, knew how to think about it. And then on the 3 right this is the act, Nuclear Energy Innovation and 4 Modernization Act.
5 And this gave us a schedule and was really 6 a foreseen function for the schedule really when we 7 did what we did. Next slide, please.
8 Okay, so I just kind of want to lay some 9 of the framework here in terms of what are the rules 10 like, you know, where does staff have to make a 11 finding when we do a fuel review?
12 And the one point that I want to make is 13 there is not one specific rule or there is not really 14 a rule which is specific to fuel qualification. The 15 rules are for the facility itself.
16 So, if you go through this paper it says, 17 you know, it can meet, you know, this regulation in 18 part and we would use a lab. But the ones that I want 19 to hit on here are design limits for normal operation, 20 anticipated operational occurrences. That's driven by 21 GDC 10 or Advanced Reactor Design Criteria 10. It's 22 in both of them.
23 We have established criteria relief for, 24 you know, for accident consequences. So, I have the 25 list of radiological consequences there that's 10 CFR 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 1 5034(a)(1) and then the other one is Part 52. But 2 there is also things to make sure that you can 3 maintain a coolable geometry. And that's coming from, 4 you know, GDC 27. It's also highlighted in ARDC 26 5 and then as well at ARDC 35.
6 Plants of course need to be designed to 7 protect against natural phenomena. The one that 8 affects fuel is really seismic. And so, we call it 9 GDC, ARDC 2 there.
10 I do want to highlight all these rules.
11 They're also consistent with what you would find in 12 Safety Standard Review Plan, like in 4.2.
13 And then the one on the bottom that I want 14 to highlight there that's on data. And it's the 15 requirements to have sufficient evidence to show that, 16 you know, a new or novel approach, you know, because 17 you have evidence for that, that you have data to 18 support things, you know, like urinalysis tools and 19 that's 10 CFR 5043(e).
20 Next slide, please. Okay. So, there is 21 some guidance out there. First, I want to highlight 22 Standard Review Plan, NUREG 0800, Section 4.2. That's 23 the one that really goes into the fuel design.
24 There's, obviously Chapter 4 is the whole 25 core. But 4.2 is the one that's most relevant to this 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 1 topic. And what's in that section, it really goes 2 through and has a reviewer look at all the known fuel 3 failure and degradation phenomena.
4 You make findings on those and ensure that 5 you have limits there. Now of course, if you're 6 looking at a design that we don't, you know, know what 7 those are so we have to write it from a more generic 8 perspective.
9 I also want to highlight the standard 10 review plan. It assumes something about the safety 11 case that the fuel plays in the overall safety of the 12 plant. It's kind of, it's not stated explicitly but 13 it's kind of baked in there.
14 This next item, ATF interim staff 15 guidance, this was some guidance that was issued to 16 staff to kind of, it would augment SRP 4.2 to help a 17 reviewer who was looking at a chromium coated fuel 18 design.
19 And that was developed by having a PIRT 20 panel together to come along and try to go through and 21 identify failure mechanisms that a reviewer can check 22 for.
23 This one on the bottom looking at, this is 24 looking at the Licensing Modernization Project and our 25 focus on risk. And when you use that you need to know 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 1 something, you know, about your source term.
2 And so, this is just to focus on there, 3 try to incorporate some of this into what we're doing 4 here. Next slide.
5 MEMBER REMPE: Tim?
6 MR. DRZEWIECKI: Yes.
7 MEMBER REMPE: This is Joy. And this 8 comment isn't really directed at any one of your 9 slides. I just couldn't figure out a good place to 10 bring it up.
11 But when I was reviewing the White Paper, 12 it talks about the three key safety functions. We 13 always have seen in the prior and existing regulatory 14 guidance documents and regulations control heat 15 generation, control heat removal and control 16 radionuclide release.
17 And a few weeks ago when we listened to 18 Bill Reckley about their ongoing efforts to do Part 19 53, he had kind of reorganized the safety functions 20 and said the big one is controlled radionuclide 21 release.
22 And then when advanced reactor designers 23 come in they're going to have to decide what the 24 subsidiary safety functions or critical functions are 25 and chemical reactions, controlled chemical reactions 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 1 was one they often mentioned in their discussion.
2 And I'm kind of wondering about that 3 philosophy and maybe that it should be considered in 4 this White Paper because I didn't see chemical 5 reactions in the White Paper anywhere.
6 And it is something that may become more 7 important with the advanced reactors. And so, what 8 are your thoughts about something like that and how 9 you could accommodate it in this White Paper?
10 MR. DRZEWIECKI: Well, okay, my first 11 reaction would be that you would have to understand 12 that that is, you know, something which is important 13 to the safety case of a fuel design.
14 And I do think that would be, you know, 15 something that could be identified as a failure 16 mechanism for fuel and that maybe you would capture 17 that in your evaluation model.
18 So, it's not quite clear to me -- so, okay 19 I will say that that aspect was not necessarily on my 20 mind when this was written. But I don't think that 21 that phenomena would be excluded, you know, a priori.
22 We tried to write it from a standpoint of 23 like any kind of failure mechanism. Now, in terms of 24 seeing it as a safety function, yes. I mean, we 25 started off from our rules.
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 1 And our rules, I can't really find it in 2 there. But, yes, I could see the head, yes. I have 3 to think about it.
4 MS. CUBBAGE: Maybe just to help out Tim, 5 I think, Joy, you raise a great point that -- this is 6 Amy Cubbage, NRC staff -- that as things evolve with 7 Part 53, we'll need to be mindful of that and you 8 raise an excellent question.
9 Tim was developing this based on our 10 current regulations to support near term applicants 11 and then ultimately we do have that need as well to 12 have regulatory guidance to support Part 53. So, 13 we'll take that back.
14 You know, with regards to chemical attack 15 on the fuel, as Tim was saying, that would be 16 considered as one of the potential degradation 17 mechanisms that would need to be contemplated in a 18 fuel qualification program.
19 As far as a fundamental safety function 20 (audio interference) to take that back.
21 MEMBER REMPE: Okay. Yes, just that's one 22 of the things that happens with ACRS. We see a lot of 23 different people come through so we try and connect 24 the dots and I think it would be good to make sure 25 those dots are connected.
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 1 MS. CUBBAGE: Yes, great point. Thank 2 you.
3 MR. DRZEWIECKI: Thank you, yes, that's 4 good. Thank you. Okay, can I have the next slide, 5 please, unless there is more comments?
6 All right. So, there is a lot of stuff 7 going on in the area right now of fuel qualification.
8 So, some stuff that is already done and approved, 9 there are two topical reports.
10 Last year you guys saw the EPRI topical 11 report. That's been reviewed and approved.
12 As well as there was a topical report that 13 was reviewed and approved that was really looking at 14 quality assurance or things that you would have to do 15 when you're looking at some of the Legacy data or 16 metal fuel specifically. So, this is a report that 17 was done by Argonne and, yes, it was approved.
18 The NRC is also sponsoring activity in 19 other areas. One I want to highlight here as far as 20 molten salt reactor fuel qualification, we tried to 21 write this framework to be as generic as possible.
22 But it was written based on our past 23 experience, which was with solid fuel. And so, if you 24 look at, you know, a molten salt fuel, some things may 25 not apply. Some things may be missing.
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 1 And so, we're getting help in that area.
2 We're being supported by Oak Ridge on this activity.
3 I believe that we'll be issuing a NUREG later on this.
4 Source term obviously has an impact here.
5 So, we've got a couple draft papers out or actually, 6 sorry, these are not draft. These are published and 7 they're out there. Next slide, please.
8 MEMBER REMPE: Tim, this is Joy again.
9 MR. DRZEWIECKI: Yes.
10 MEMBER REMPE: And this question may not 11 be fair to ask you because I don't know who from the 12 staff approved the Argonne quality assurance program 13 plan. I am familiar with it and I saw it.
14 But I guess, is it fair to ask, I was 15 puzzled why the staff in their safety evaluation of it 16 agreed to -- that they have like three ways you can 17 qualify fuel and one of them is a peer review. One of 18 them is corroborative data.
19 And typically NQA-1 has new test data and 20 Argonne omitted that from the document. And is it 21 just because they will never, ever have any sort of 22 additional data or is it fair to even ask you?
23 Maybe you weren't the person who reviewed 24 it. But it never came to us and I just was puzzled 25 why that was highlighted in the safety evaluation.
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 1 And maybe someone else can answer it if you weren't 2 the person involved.
3 MR. DRZEWIECKI: It was not. And I don't 4 know if the person is here because that was done by 5 our Quality Assurance Branch.
6 MS. CUBBAGE: Yes, I can chime in just 7 from a very high level. Tim, this is Amy. That 8 document was aimed at a process to demonstrate quality 9 for legacy data.
10 MEMBER REMPE: So, it just wasn't 11 applicable because you wouldn't have new data with it.
12 Okay, because I just -- you know, when I was looking 13 at the safety evaluation and I wasn't part of the 14 discussions, it seemed strange.
15 And that was the only reason I could think 16 of. But thank you. That's good enough. I just was 17 curious. Trying to get a good background here.
18 MR. DRZEWIECKI: Okay. Next slide, 19 please. Okay, there are some white papers that are 20 being issued by -- this is by, being submitted by 21 TerraPower to look at how they want to qualify fuel.
22 And so, staff is doing like a preliminary 23 review and giving feedback and comment on these. So, 24 there are going to be a series of these papers.
25 The first one that, I believe was looking 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 1 at the fuel rod has been done. And we are expecting 2 some more papers to be submitted this month actually.
3 There is another effort going on. This is 4 the AFQ effort that's being led by General Atomics.
5 They've had, you know, a lot of comments so far on 6 this paper.
7 They've been, you know, volunteering 8 comments and have been active at the stakeholder 9 meetings, things like that. And we've been engaged in 10 those meetings too.
11 We don't have a role in writing anything.
12 But we do attend and observe the meetings and give 13 presentations and things like that.
14 Then again, WGSAR we did, there is a 15 sister paper to this draft that is being published 16 through WGSAR and that has authors from several 17 regulatory bodies. Next slide, please. Okay, so --
18 CHAIRMAN PETTI: So, Tim?
19 MR. DRZEWIECKI: Yes.
20 CHAIRMAN PETTI: A question. On the 21 international NEA report how broad is the 22 participation internationally? Who is at the table?
23 MR. DRZEWIECKI: Let me, so I've got a 24 slide on that. But yes, it's Canada, France, Germany, 25 IAEA, Italy, Russia and the UK.
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 1 Now, I've got to say, you know, a lot of 2 the writing was done by me. But there was also 3 significant contributors from the UK and from France 4 as well that wrote a lot. But as far as ideas it was 5 reviewed by that whole body.
6 MS. CUBBAGE: And then, yes, more broadly 7 the group is several countries plus the IAEA and the 8 European Commission. This is Amy Cubbage, Chair of 9 the WGSAR.
10 CHAIRMAN PETTI: Thanks.
11 MR. DRZEWIECKI: Yeah and the one thing 12 that paper has that this does not have is we got input 13 from GIF or the Gen IV International Forum. It had 14 gone through and did a, kind of a high level of 15 overview of all the fuel types that are used in Gen IV 16 reactors and what could be some of the challenges at 17 a fuel qualification.
18 So, it does have that which is a bit 19 longer. Some language is different to reflect, you 20 know, some changes in terminology. For example, what 21 I'll say in this paper as a safe shut down, they refer 22 to it as a safe state there.
23 Also, there is a little more elaboration 24 on the AFQ stuff in this paper which is really not in 25 the NEA paper. Okay, next slide, please.
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 1 Okay. So, this is just there to show, you 2 know, people, you know, what was one of the forcing 3 functions in terms of the schedule to get this done 4 and that, you know, staff was guided in order to come 5 up with some guidance in the area of a fuel 6 qualification.
7 And so, this draft paper serves to do 8 that. We're going to convert it into something that's 9 more formal. Next please.
10 Okay. So, these are a couple papers.
11 Obviously, the one on top is going to be familiar to 12 some people in the, on this call. You know, Dr. Petti 13 is one of the authors here.
14 But this, you know, a 2007 paper that kind 15 of lays out a framework, you know, in qualified fuel.
16 And it lays out what I would say is a test-based 17 approach.
18 And, you know, it spans a time frame of 19 about 20 years, that are highlighted there, in order 20 to go from the concept all the way to having a 21 qualified fuel for use in a reactor.
22 Now, some more recent work has been 23 focused on trying to speed that up by using things 24 like advanced modeling and simulation. And that's 25 this 2020 paper here.
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 1 The one thing I do want to highlight in 2 both of these is that they both end up in this spot 3 where you're doing integral, say engineering scale 4 tests. The AFQ process to date, and I have slides on 5 this. We're going to back up.
6 They're not trying to get away from that 7 final step of the design qualification. Next slide, 8 please, unless there are any comments.
9 Okay. So, yes, going back to the kind of 10 stakeholder input that we had, you know, through 11 WGSAR, you know, members from, you know, Canada, 12 France, Germany, IAEA, Italy, Russia and the UK.
13 So, there was a lot of writing sessions 14 there. So, that involvement was more formal, had a 15 lot of review there.
16 Domestic stakeholder input that we got 17 from our stakeholder meetings that we've had. We've 18 gotten comments from the Union of Concerned 19 Scientists, Nuclear Industry Council, Southern Nuclear 20 Company, Kairos, General Atomics, Idaho National 21 Laboratory as well as some members of the public.
22 And so, we've -- now those have not been 23 formal comments. But they have been stated at those 24 meetings and we try to capture them and incorporate 25 them into the paper.
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 1 We do have a group inside of the NRC, what 2 we call a Technical Advisory Group on Fuel, TAG-F. We 3 meet periodically to go over, you know, any kind of 4 fuels issues that are going on across the agency.
5 Major participants there are from, you 6 know, this office, NRR. Used to be NRO and NRR but 7 now we're all together, so that's why I'm saying --
8 new, and the op (phonetic) fleet are there. People 9 from RES and NMSS. And they help kind of lay out the 10 framework and, you know, give some input there.
11 As well as we've gotten, you know, vendor 12 input through the AFQ group. So, I've highlighted 13 that group is being led by General Atomics. But they 14 have a lot of stakeholders that are there as well, 15 people from Westinghouse, Framatome, Lightbridge and 16 the laboratories there as well.
17 Next slide, please. Okay, so there I was 18 trying to highlight, you know, how we kind of got 19 here. What are the rules, you know? What are the 20 forcing functions as well as who has been involved?
21 And so, now I'm going to go into the 22 framework a little bit itself, kind of highlight what 23 that is, you know, what's our definition of fuel 24 qualification and things like that. Next slide, 25 please.
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 1 Okay. So, we began working on this paper 2 especially with our work at NEA and WGSAR. Some of 3 the early feedback that we got was -- or some of the 4 early input was it was a very broad topic.
5 We had, you know, people considering 6 things in terms of the area of reactor physics, 7 critical heat flux, you know, how you store frameworks 8 and stuff. And so, we wanted to kind of bring in the 9 scope.
10 And so, we figured we would need to have 11 a scoping statement and this is what we have in the 12 paper. But really this paper is trying to focus on 13 fuel, life limiting and degradation mechanisms that 14 occur as a result of irradiation.
15 So, somebody who does fuels all the time 16 or who, you know, this may sound familiar to you but 17 we did want to bring that in. So, it looks more like 18 what you would find in SRP 4.2 type thing.
19 Next slide, please. Okay, so now I want 20 to hit on this concept of, you know, what I mean by an 21 assessment framework. And so, this is something that 22 we've done before.
23 It shouldn't be too foreign. But really 24 it's a top down approach. We're starting with the 25 high level goal that can be somewhat, you know, 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 1 abstract like fuel is qualified.
2 Break that down into supporting goals that 3 may still be abstract and keep going down until you 4 have goals that you think are pretty objective, that 5 are less subjective.
6 Now, you know, we didn't get to a point 7 where we got to things that were fully objective.
8 Some level is going to, you know, still require some 9 type of judgment there.
10 But for the most part, we think we broke 11 it down pretty well. This isn't the first time that 12 we've done this.
13 Certainly there is guidance out there like 14 Reg Guide 1.203 which is that MDEP process for 15 looking, you know, at transient methods in which, you 16 know, you break it up into all these boxes and all 17 these findings that you make.
18 But something that's more recent that I 19 was personally involved in was this thing to develop 20 a critical heat flux assessment framework, a critical 21 boiling assessment framework. And so, that was 22 actually led by Josh Kaiser.
23 But this framework has been used probably 24 six or seven times now. And we saw significant 25 reduction in the review time as well as we thought we 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 1 had a review that was more comprehensive and 2 transparent and seemed like it was kind of easier to 3 follow all the way.
4 Even people during our review and 5 concurrent process it just kind of made all that a lot 6 smoother. We saw speeds up on the order of like five 7 I think on that.
8 Next slide, please. Okay, so now I'm 9 going to bring in the definition of fuel 10 qualification. And what we saw in that, you know, 11 2007 Journal of Nuclear Materials paper we thought 12 laid it out pretty well.
13 And that is, you know, a fuel that is 14 qualified is, okay -- I'm sorry, the objective of the 15 fuel qualification is demonstration that a fuel 16 product fabricated in accordance with the 17 specification behaves as assumed or described in fuel 18 safety case. That's the focus of this paper.
19 It obviously goes on further to talk 20 about, you know, the reliability of the fuel which of 21 course is important. But this paper is based on the 22 safety case.
23 And with that, you know, you have to 24 clarify what you mean by safety case. And so, if you 25 -- one thing that is I think a good example is if you 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 1 compare say a TRISO fuel versus, you know, a 2 traditional light-water reactor fuel in which you, you 3 know, have barriers in the fuel itself in TRISO fuel 4 and you could use it to support something like a 5 functional containment approach as opposed to a light-6 water reactor fuel where you are expected to have a 7 robust containment, you may have a different safety 8 case.
9 Okay, next slide, please. Okay. So, now 10 these next slides are just going to walk through the 11 framework itself. And so, we'll just start off with 12 the high level goal and then we'll break that down and 13 try to go through most of the branches. We're not 14 going to go through all of them.
15 We're going to go through most of it. So, 16 again our top level goal is that if you have fuel that 17 is fabricated in accordance with the specification it 18 will perform as described in the applicable licensee 19 safety case.
20 One note that I do want to highlight here 21 is, you know, I want to bring your attention to a 22 couple of word choices that I think are going to 23 change because they have been flagged as being 24 somewhat problematic. And that's the word high 25 confidence.
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 1 And that's used over and over again. So, 2 that's something that, you know, that's going to 3 change in the paper. But I just wanted to highlight 4 that here, bring your attention.
5 I also want to state as I walk through 6 these things there is a color coding to it. So, if a 7 box is white that means it's going to be broken down 8 more. If it's gray it means that's the terminal goal 9 that you would make a finding on that goal.
10 MEMBER REMPE: So, Tim, how are you going 11 to change high confidence? Because that as well as the 12 use of conservative were things that did catch my eye.
13 MR. DRZEWIECKI: Yes. In terms of the 14 term that we'll use it may be something like, you 15 know, reasonable assurance or something like that.
16 We'll probably have to brainstorm more about that to 17 figure out, you know, what's the right term to use.
18 We may just, you know, leave that just to 19 a statement. So, I'm not quite sure right now. I 20 can't answer that on the spot.
21 We have to think about what's the proper 22 word choice there. If you have any thoughts that 23 would be --
24 MEMBER KIRCHNER: Tim, this is Walt 25 Kirchner. Your statement here, the goal is slightly 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 1 different than your definition in the preceding view 2 graph.
3 I actually think that this is a better 4 definition and goal than the preceding one because the 5 preceding one says behaves as assumed or describes.
6 Behaves is an interesting word.
7 But perform is more accurate, I think. I 8 don't want to be splitting hairs on this. But 9 definitions are important. And I think this is a 10 better statement here than the preceding view graph.
11 So, I'm saying I like it. But it's not 12 exactly the same as the definition in the previous.
13 MR. DRZEWIECKI: Okay, yes. Thank you for 14 that. Yes, that's a good point. I should make that 15 more clear because, yes, you're right. You know, 16 what's on the previous slide is, you know, a quote and 17 I just kind of copied that.
18 But the reality is, yes, you're right.
19 It's not a definition. And yes, thank you for that.
20 I'll make that correction.
21 MEMBER KIRCHNER: Not to dwell on it. But 22 this is a much more definitive statement. It doesn't 23 say anything about assume.
24 It will. It's like shall. It shall 25 perform as described, you know. So, probably enough 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 1 said. Thank you.
2 MR. DRZEWIECKI: Thank you.
3 CHAIRMAN PETTI: So, Tim, just a comment 4 on these words of high confidence. To me it's a 5 function of the role the fuel plays in the safety 6 case.
7 You know, we require 95/95 confidence 8 intervals on CHF for instance and LWRs. TRISO fuel 9 has always used 95/95 since some NUREG in the past 10 that GA brought in years ago.
11 But if you had a system where the fuel 12 didn't have that central a role, I think there might 13 be wiggle room to argue for something more like 14 reasonable assurance, particularly if there is large 15 margins.
16 So, sometimes the concept of margin needs 17 to somehow be worked in, I think as well. Again, 18 depending on the reactor and the technology associated 19 with it.
20 MEMBER REMPE: So, I think that would be 21 fine. I just think it used to have a paragraph 22 whether you use reasonable confidence or reasonable 23 assurance or high confidence related to the required, 24 it will be within the, you know, help them meet the 25 required safety margins or something so that a design 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 1 developer knows they've got -- what is expected from 2 them by the staff.
3 MR. DRZEWIECKI: Yes. Just so, yes, so 4 where I'm trying to get to is that if you met Goal 1 5 and you met Goal 2, like if you, you know, if you were 6 able to make a finding that, you know, that there is 7 a fuel manufacturing specification that controls the 8 key verification parameters and were able to make a 9 finding, you know, that the safety criteria can be 10 satisfied or, you know, whatever word we choose there, 11 you know, that that means the top level goal is met.
12 And so, then hopefully that will be clear 13 as I roll through this thing. Okay, but you're right.
14 Yes, I'll make it a point.
15 Okay. Can I have the next slide, please?
16 Okay. So, actually this is one that I would like to 17 get some, you know, some more feedback on.
18 So, this is in terms of like, you know, 19 basically having a fuel manufacturing specification 20 that can control the key verification parameters. And 21 so, in looking at ones that we've seen so far this is 22 the elements really called out.
23 And so, you know, key dimensions I think 24 is pretty straight forward. You know, key 25 constituents with allowances for impurities. There is 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 1 a box on the right that talks about microstructure 2 attributes.
3 The language in the paper itself, I mean 4 we haven't seen people, you know, describe what that 5 structure is. But normally what's done is they will 6 describe a heat treatment or will have acceptance 7 criteria based on the heat treatment to kind of get to 8 that.
9 Some comments we have received so far at 10 least, you know, the past couple weeks is this may be 11 too specific and maybe we should use a different term 12 there like end state that would encompass 13 microstructure.
14 So, that was one thing that I wanted to 15 bring up. The other thing is the fact that we also 16 recognize that the life cycle of a fuel design can be 17 so long such that certain manufacturing, you know, 18 processes can change.
19 So, it was not our intention to pin people 20 down to a specific manufacturing specification, but to 21 have a sufficient regulatory footprint in order to pin 22 down certain key attributes that we think would affect 23 the performance of the fuel.
24 CHAIRMAN PETTI: So, Tim, my take on this 25 is that, yes, if you're going to make minor changes to 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 1 the fabrication process that's one thing. But if you 2 decide to make the fuel in a very different way, let's 3 look at metallic fuel that's cast versus extruded, the 4 database is largely based on irradiations from cast 5 fuel.
6 Extruded fuel can have a texture. And so, 7 there are some attributes, microstructure to me is 8 okay, that I would think they themselves would want to 9 know that they're getting the same product from the 10 two processes.
11 There has to be some equivalence. And 12 maybe that is, it's a microstructure or a process, you 13 know, that there is a subsequent heat treatment so 14 that, you know, they look the same.
15 But microstructure is a holy grail of 16 materials development. I think it needs to be in 17 there when you're talking about the different idea of 18 how to heat this fuel compared to what's been done.
19 MEMBER KIRCHNER: Dave, could we alert 20 whoever's cell phone or phone number 410-678-1803, 21 would you mute your phone?
22 MR. WIDMAYER: Hey, Walt.
23 MEMBER KIRCHNER: Yes.
24 MR. WIDMAYER: That's the public line.
25 MEMBER KIRCHNER: What?
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 1 MR. WIDMAYER: That's the public line.
2 MEMBER KIRCHNER: It's getting a lot of 3 interference.
4 MR. DRZEWIECKI: Okay. I just muted it.
5 I mean, can we mute that line until we get to a 6 portion where we can open it up?
7 MEMBER KIRCHNER: Yes, Tim, that's fine 8 because it was interfering with your presentation.
9 MR. DRZEWIECKI: Thank you.
10 MEMBER KIRCHNER: And I have a comment too 11 on this one, Tim. This is Walt Kirchner.
12 On microstructure I'm not sure that's the 13 right word, but I know what you're getting at because 14 the actual grain structure like in oxide fuels and 15 other fuel types can have an enormous impact on 16 fission gas release, as an example.
17 So, it's not enough to just get the first 18 two boxes right. It is important for solid fuel forms 19 to actually control the microstructure because that 20 will have a very important impact on things like 21 fission gas release, swelling, gap closure if it's a 22 clad fuel.
23 I could go on and on. So, I think it's an 24 important aspect that can't be ignored.
25 MR. DRZEWIECKI: Thank you. Really good 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 1 examples, thank you.
2 MEMBER BALLINGER: Yes, this is Ron 3 Ballinger. I agree and understand what Walt is 4 talking about.
5 But we need to be, I think a little bit 6 careful that we don't -- that the specification 7 doesn't get into micromanagement. And that's a fine 8 line.
9 I understand that for the manufacturing 10 specifications that's tied ultimately to the 11 performance. And you've assessed the performance and 12 decided what manufacturing specification is required 13 to achieve that performance.
14 But micro -- but making specifications so 15 tight that you don't allow a vendor leeway, maybe 16 that's the wrong word. But I just think we should be 17 a little bit careful not to imply micromanagement.
18 MEMBER KIRCHNER: Yes. But, Ron, this is 19 Walt. But the thing is here as you well know, no 20 matter the fuel form you've got to, whether it's the 21 composition, the amount of uranium say versus oxide or 22 the heavy metal loading or whatever parameters, it's 23 not micromanagement.
24 Let them define it. But then they have to 25 be able to stick to it and demonstrate that that 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 1 microstructure performs under, you know, irradiation 2 and thermal conditions to meet their requirements in 3 terms of the safety case.
4 MEMBER BALLINGER: I agree. But there is 5 a big difference between an oxide fuel and a metallic 6 fuel with respect to the importance of microstructure.
7 MR. DRZEWIECKI: Yes. There is language 8 in the paper -- I just want to highlight that there 9 was language in the paper.
10 For example, you know, I haven't actually 11 seen the evidence myself but I've heard of the fact 12 that, you know, if you have, you know, say like a 13 metal fuel and it's, you know, and it's injection cast 14 that it may not be sensitive to other, you know, yes 15 --
16 MEMBER BALLINGER: Yes, the Lightbridge 17 fuel, for example that's extruded. But anyway --
18 MR. DRZEWIECKI: Okay. And so, yes, and 19 so there was language in there that you could justify 20 that, you know. That's not sensitive to that.
21 And so, we just think that, you know, as 22 a reviewer, you know, just trying to get you to kind 23 of look there to make sure that you could either 24 justify or make a finding there.
25 So, yes. But, yes, thank you. You know, 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 1 great comments. You know, a great conversation. This 2 is similar to the kind of feedback that we get, you 3 know, at our AFQ meetings by the way. I mean it's hard 4 to get it right, I think. And so, you know, feedback 5 here is, you know, very welcome. Next slide, please.
6 Okay. So, this is going into that goal 7 that was on the right. You know, which of the safety 8 criteria can be satisfied.
9 And this is really coming from our rules 10 themselves. So, we have a Goal 2.1 which is, you 11 know, which is looking at like the margin to design 12 limits under normal operation including AOOs.
13 The box in the middle is looking at, you 14 know, an accident source term there making sure that 15 you can demonstrate that you, you know, have a 16 release, you know, which is within limits.
17 And then the box on the right is looking 18 at the safe shutdown. And just to get the safe 19 shutdown, I don't really break it down necessarily in 20 the main body of the slides.
21 It is in the back up. But I did want to 22 highlight what we're talking about here is maintaining 23 the coolable geometry and maintaining the ability to 24 insert a reactivity control element.
25 Next slide, please. Okay, so now starting 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 1 from that structure I tried to kind of, you know, have 2 that here on the top right and then highlight the fact 3 that I'm in this branch on the left now which is the 4 margin to design limits under normal operations and 5 AOOs.
6 And again, I have this, you know, color 7 coding here. And so, the box on the left is, you 8 know, define the fuel performance envelope.
9 And the box on the right is have an 10 evaluation model to, you know, to assess it over that 11 envelope. So, that's -- you know, that's a pretty, 12 that's pretty simple which is really know where you 13 are going to be and have a tool to do an evaluation 14 when you are there.
15 And so, in terms of defining a fuel 16 performance envelope we do think it's pretty 17 straightforward. But we have some notes there, you 18 know, to say that, you know, it should cover things, 19 you know, like your normal ops.
20 It should also cover, you know, what kind 21 of DBAs you're going to have and things like that too 22 because it's not only used to support this goal, it's 23 used to support other goals too.
24 But now I'm going to go into the 25 evaluation model aspects. Next slide, please. Okay, 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 1 so this is looking at you have acceptable evaluation 2 model.
3 Two goals here again, they're pretty 4 straightforward, is one that you have appropriate 5 modeling capabilities which is important. But I do 6 want to highlight that, you know, Goal 2 we think is 7 more important. And that is that that tool has been 8 assessed against data.
9 I also want to make a statement here in 10 terms of what we mean by evaluation model. We're 11 using this as a generic term.
12 And what I mean by that is, you know, 13 traditionally evaluation model especially for fuel 14 could be a sophisticated code something like a BISON 15 or, you know, a LIFE-METAL or FAST, something like 16 that.
17 It doesn't have to be. We think that 18 there could be some scenarios where you can have just, 19 you know, see a spreadsheet or just some hand 20 calculations. If you have the margin, maybe that will 21 work. But anyway, next slide, please.
22 Okay. So, as far as capabilities of the 23 model itself, I do want to highlight that these goals 24 here were largely influenced by some of the work that 25 came out of Sandia, this capability maturity 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 1 measurement models which kind of breaks down the 2 things that you have to do. You've got to have 3 confidence in the tool. And so we think, as far as 4 these goals, be able to model the geometry. Be able 5 to model the materials in that fuel as well as in its 6 surrounding environment and have the appropriate 7 physics.
8 Now, physics of course was going to be 9 things like heat transfer and things like that. But 10 I also wanted to highlight that this is kind of where 11 you should be able to have the appropriate models to 12 capture the fuel failure mechanisms.
13 And to get that to kind of support those 14 findings one thing that would be called out is, it 15 would obviously be -- one thing that we've seen used 16 a lot and which is kind of called out in that MDEP 17 Model or Reg Guide 1.203 is the use of a PIRT panel or 18 an expert panel to help you go through.
19 I do have a caveat here though that like 20 whatever you do, we expect that the model is going to 21 be assessed by data. And so if there's errors in 22 there, we should be able to quantify what those are.
23 So, next slide, please. So, model 24 assessment. Assuring that, that you've assessed a 25 model of, I guess appropriate data.
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 1 Again, I have this blue box here because 2 we have a separate framework that only looks at data, 3 because that's really one of the big drivers in this 4 whole thing is data that's going to underpin the whole 5 evaluation of this.
6 But this goal on the right, Goal 2.2, that 7 the evaluation model has demonstrated the ability to 8 predict fuel failure and degradation mechanisms over 9 a test envelope. And so, what does that mean?
10 Next slide. So, some of these are 11 straightforward. So, to make that finding, have you 12 gone through and tried to quantify error in your model 13 versus how it performs against data? So, that should 14 be a pretty objective check. Is that model, does it 15 actually ban your performance envelope? Is there 16 sparse data regions, and if there are, can you justify 17 them?
18 And that we have some means to restrict 19 the use of that model within its test envelope or an 20 area where it's not validated. Now, there was 21 language in this paper that tries to argue that there 22 may be scenarios in which you can justify 23 extrapolation outside of your test base.
24 And this is an area in which we've gotten 25 some input from the AFQ community trying to argue in 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 1 a way that having a physics based model may make that 2 an easier thing to do versus a purely empirical model.
3 And so, some of that language is in this 4 paper, trying to highlight some of those things.
5 Okay, next slide.
6 Okay. So, now I'm just looking at the 7 data itself. What do we expect in terms of the data 8 that's going to be used to assess your model?
9 One, it should be independent. Now, there 10 was language in this paper as well which highlights 11 the fact that in some areas you may have very limited 12 data. For example, design basis accident testing.
13 You may not have a lot of points where you can go 14 through, train a model and then separate data in order 15 to do the validation.
16 So, got to have some kind of flexibility 17 there. But in areas -- you should try to make some 18 kind of argument as best you can that data is 19 independent. That you've collected the data over a 20 test envelope that's going to cover your performance 21 envelope. And we do want to highlight some testing 22 that we think they should do there.
23 This list was actually largely informed by 24 the Journal of -- of a 2007 paper from the Journal of 25 Nuclear Materials, which highlighted steady state 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 1 medical testing, high power and cooling tests, power 2 ramp testing to cover things like especially if you're 3 going to do something say like load follow with the 4 reactor design, and design basis accident tests.
5 Then we have these other two goals that we 6 think are, that are broken down further. One is that 7 you measure your data accurately and that the test 8 specimens used in that testing actually represents 9 your actual fuel design. Next slide, please.
10 MEMBER KIRCHNER: Hold on. The last one 11 bears some, perhaps some conversation, Tim. This is 12 Walt Kirchner.
13 MR. DRZEWIECKI: Yes.
14 MEMBER KIRCHNER: Representative, do you 15 mean literally prototypical of the configuration, both 16 dimensions and material composition and 17 microstructure?
18 MR. DRZEWIECKI: Well, in part. Some of 19 those, okay, so I have a slide. It's two slides away, 20 because this gets broken down more in terms of what 21 that means.
22 MEMBER KIRCHNER: Okay, I can wait.
23 MR. DRZEWIECKI: Okay, okay. Yeah, okay.
24 All right, so next slide. This will just be over, 25 okay, yes. So, this is just a small detour.
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 1 But it's, okay so in terms of, is your 2 data measured accurately, and if the first goal here 3 is that you have a quality assurance program for that 4 facility or somehow can make that argument. And I do 5 have a note there that we do expect that, if you had 6 issues with, say a malfunctioning or broken 7 instrumentation, that your QA program would take care 8 of that.
9 I understand that this has happened in the 10 past. And so, but normally, staff appear, you know, 11 at White Flint wouldn't always be aware of that. So 12 this could be a challenging thing.
13 But anyways, yeah, I just had that note 14 there. You know, the data -- it was collected using 15 established, well understood measurement techniques.
16 And then the goal on the right that you 17 have some kind of error analysis on your data so that 18 you know if there are sources of uncertainty and 19 things like that, that's been accounted for.
20 Okay. So, next on test specimens. And, 21 yeah, this I think is a good topic. And so, in terms 22 of the microstructure, I do want to highlight that 23 test specimens are fabricated consistent with the 24 manufacturing specification.
25 Now, I also understand that you may not 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 1 have a finalized specification at the time of the 2 testing. But we think that you can justify that.
3 And, just going back to the points in 4 terms of, what's some of the impact that you could 5 have in terms of the microstructure on how it behaves 6 in certain things. So I do think that it would be 7 important that those are there. But there is also 8 this other goal that if you had any kind of 9 distortions --- and the term distortion really comes 10 from, anyone who has done, like, thermal hydraulic 11 scaling work. It kind of came from there. But I 12 thought it fit here.
13 And this has to do with any kind of 14 differences, and if you had a different fabrication 15 technique, can you justify that? Is it a different 16 size?
17 One thing that's obvious, like, if you do 18 transient testing in a test reactor, a full size 19 specimen is not going to fit in there, right. So it's 20 kind of expected.
21 But we just want people to be looking 22 there. Any more discussion? Walt, did that get to 23 your comment?
24 MEMBER KIRCHNER: No, I have some -- I 25 think probably this is an area where it will be case-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 1 specific, based on the advanced reactor concept. And 2 if they're relying, I'm trying to say this in a very 3 generic way. If they're relying on a past database 4 for their particular fuel type, one of the 5 considerations that may become important is how 6 relevant is, if the structure, say they're using the 7 same fuel material, but different structure or 8 different manufacturing technique and so on, then it 9 raises the question, how relevant the past irradiated 10 experimental database may be for application for this 11 new design.
12 I said that, I have a few specific 13 examples that are not appropriate to bring up here.
14 But, yeah, it would -- this would be perhaps the area 15 where the staff may have to put added effort to review 16 what the applicant, if the applicant is relying on a 17 past database, but they've changed the geometry 18 substantially, then, and there is no current 19 irradiation of that new geometry, for example, then 20 that raises a number of questions about things. You 21 know, simple things like, does the structure crack or 22 whatever under operating conditions versus the 23 previous designs?
24 MR. DRZEWIECKI: Yeah, yeah. And, I mean 25 I think we're going to be there in several breaker 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 1 designs because I mean, especially designs that are 2 going to rely on the EBR-II database. And so, yeah, 3 I hear you. Thank you. Okay. Can I have the next 4 slide, please?
5 So, yes, so it's an overview of the 6 framework. Two goals we did not break down, but 7 they're in the backup slides, are the ones associated 8 with radiological release and then the one that's 9 associated with maintaining a coolable geometry. So, 10 those were two of the other safety criteria.
11 But they were very similar in approach to 12 what we have for AOOs and things like that. However, 13 there is some language inside of the paper which 14 highlights the fact that we may not have as much data 15 for things like, for some of those testing, because 16 some of the DBA testing can be destructive. And 17 that's got certain risks associated with it that you 18 may not want to collect a bunch of data.
19 But I want to highlight. So, in terms of 20 the overall framework, you have your main framework 21 and that's supported by two other ones. One on 22 evaluation models, another one on experimental data.
23 A total of 60 findings or specifications.
24 And so, somebody who is doing a review 25 would go through, you know, try to find, you know, try 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 1 to make smaller findings in all these areas and that 2 would support the overall finding that the fuel is 3 qualified for use.
4 Next slide, please. Okay. So, all that's 5 left is to talk about what our next steps are. What 6 we're going to do with this and, yeah, next slide, 7 please.
8 So, one thing that we have to do is to go 9 through and exercise this framework. So, before I had 10 mentioned that we could have done something similar in 11 the area of critical heat flux and we certainly knew 12 where some of the gaps were or some of the challenges 13 were just by using it, and trying to exercise it. And 14 that helped out a lot.
15 And so, we're trying to do that here. We 16 are in the process of placing a contract to work with 17 Argonne and Idaho National Laboratory to evaluate a 18 generic metal fuel design using this in order to see 19 if there's any gaps, any information and also to see 20 if there's gaps in our model and to see if there's any 21 gaps or anything that could be done to help support 22 licensing of this fuel.
23 And I do want to say that what we have 24 here this is consistent with the approach that we're 25 trying to apply for the Aurora COL which is reliant on 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 1 EBR-II fuel data which, you know, back to Dr.
2 Kirchner's point, may look a little bit different 3 than, you know, our EBR-II fuel.
4 Next slide, please. Okay. So, in terms 5 of what we have to do. Convert this into a NUREG.
6 That actually has been done.
7 But we have gotten comments just a few 8 weeks ago, you know, that were volunteered by the AFQ 9 Working Group and, you know, we will get some more.
10 But we're going to try to work on those comments, 11 update the paper accordingly. Go through legal review 12 and to make sure that we're not saying anything wrong 13 there, and then go through a formal notice and comment 14 and come back and talk to you guys in September at a 15 full committee meeting. So, that's what I've got.
16 MEMBER KIRCHNER: Tim, this is Walt again.
17 To Joy's earlier point, have you -- I was thinking 18 about this. I didn't have a chance myself to go 19 through the exercise.
20 Have you walked through your framework for 21 liquid fuel reactors? And are there any changes or 22 additions?
23 Certainly, you know, there since you're 24 intimately mixed with the coolant, then chemistry 25 becomes extraordinarily important. Also, well, you 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 1 could have it with solid fuel, too. But eutectics and 2 liquid fuels is a major consideration as well.
3 Have you had a chance to just kind of 4 mentally or just kind of desktop exercise go through 5 any of this for liquid fuel, and does it kind of touch 6 all those same bases that you think you would need for 7 those concepts?
8 MR. DRZEWIECKI: So, you know, we have not 9 beyond the work that we have contracted to have done 10 for molten salt reactor fuel qualification. And so, 11 you know, so I think some of that activity has been 12 done.
13 Of course, that work was started before 14 this draft was out there. And I think that they've 15 recently been looking at how to incorporate some of 16 these ideas.
17 We do recognize that for this framework it 18 really was developed for, based on what we've done in 19 the past, which was all solid fuel.
20 DR. CORRADINI: Tim, this is Corradini.
21 I had a question.
22 When you were talking to Walt about his 23 questions relative to the specifications, does the 24 staff have a preference whether it's a product 25 specification for the fuel or a process specification?
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 1 MR. DRZEWIECKI: I mean, no, I don't.
2 Just as long as you have -- you know, we just want to 3 get to a point where we have some confidence that you 4 can lock down certain things that we think are going 5 to be key.
6 Now, going the process, maybe that will be 7 easier. And frankly, that's what we've always seen.
8 We've always seen people describe a heat treatment.
9 And frankly, we have acceptance criteria that are 10 based on the heat treatment for a clad or something 11 like that.
12 So, that's what we've seen. But I 13 wouldn't say that I'm partial either way.
14 DR. CORRADINI: Well, the reason I'm 15 asking the question the way I did is, it seems to me 16 it will allow for a diversity of solutions as long as 17 it's a product specification, so you're not locking 18 down the recipe.
19 You could have multiple recipes, to the 20 extent that the product specification is complete 21 enough that you prove that you've met the 22 specification. Then you could do it a number of 23 different ways. That seems to me to be more 24 preferable.
25 MR. DRZEWIECKI: Yes.
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 1 MEMBER BALLINGER: This is Ron. That's 2 what I was trying to at least allude to in the 3 previous comment I made, that not getting to, you 4 don't micromanage too much.
5 DR. CORRADINI: That's what comes to mind.
6 MEMBER KIRCHNER: Yeah, Mike and Ron, I 7 think a product specification would be preferred, 8 because in the final analysis, that's what you're 9 concerned about.
10 You know, the process part has a lot to do 11 with reproducibility, not generating a lot of waste 12 product and so on and so forth. But in the final 13 analysis, it's the product spec that you really have 14 to meet so that you can demonstrate it's going to meet 15 the safety licensing case.
16 CHAIRMAN PETTI: And the completeness of 17 that specification. You know, does it have everything 18 that imparts the good behavior to the fuel, yeah.
19 DR. SCHULTZ: Tim?
20 MR. DRZEWIECKI: Yes.
21 DR. SCHULTZ: This is Steve Schultz. I 22 want to talk a little further on the qualification 23 testing portion of it, to follow on what Walter was 24 talking about, at least partially.
25 And that is the way the structure is set 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 1 up it seems like it's a very nice program and process.
2 But it assumes a lot about having available, if you 3 will, a fairly final design and experimental program 4 that leads from that design to testing and 5 qualification.
6 Most of the development and then 7 evaluation of fuel products are not, have not in the 8 past been performed that way. In other words, the 9 design is established based upon a wide range of 10 experimental databases that have been accessed in 11 order to move through the development.
12 And it's usually not possible to have what 13 you might consider or want to consider to be a final 14 design or a prototype design that looks just like 15 you're going to have in reactor with the envelope 16 established and so forth to do that full program 17 testing.
18 In other words, the justification of the 19 qualification is usually based upon a wide variety of 20 testing programs.
21 CHAIRMAN PETTI: But ultimately, Steve, 22 there is like sometimes a lead test assembly. Some 23 fuel folks call them proof tests.
24 DR. SCHULTZ: Yes.
25 CHAIRMAN PETTI: You know, at the end, so 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 1 that you try to, you know, there's all these changes 2 that have occurred over the development. But in the 3 end --
4 DR. SCHULTZ: Right.
5 CHAIRMAN PETTI: -- you test the final one 6 to make sure that there's nothing, it's more than 7 empirical proof. But --
8 DR. SCHULTZ: Yeah, I do see that at the 9 end and I see it in the qualification testing and the 10 prototype assembly that might go into the operational 11 testing portion of it.
12 But when you're talking about the 13 qualification of the fuel design for the whole 14 envelope of testing that's described earlier on, 15 that's got to draw upon a much broader experimental 16 database in order to set up the qualification of the 17 analysis tools and then justify how the fuel is going 18 to perform in those environments.
19 To have something that looks like a final 20 design which we set up in the first part here and 21 expect that's going to be justifiable through testing 22 in all of these experimental areas is really expecting 23 too much.
24 MR. DRZEWIECKI: Jordan, can you go to 25 Slide 40, please? So, I just wanted to highlight 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 1 this. And this next one, too.
2 So, this may look familiar to Dr. Petti.
3 This is coming off from that paper.
4 CHAIRMAN PETTI: 2007?
5 MR. DRZEWIECKI: Yes, 2007 Journal of 6 Nuclear Material papers, that kind of highlights some 7 of the steps. And that's what I thought that you were 8 kind of getting at is some of the earlier stuff that 9 you have to really draw on to inform some of your 10 decisions.
11 But I do want to state we were writing 12 from a perspective of this kind of last thing, that 13 people are going to do integral -- maybe like 14 engineering scale tests.
15 MS. CUBBAGE: This is Amy Cubbage. I 16 mean, I think your comment may be just reflective of 17 the iterative nature of the reactor design business, 18 in that you're going to start off on a fuel 19 development project with a design in mind and you're 20 going to start your design with a fuel in mind.
21 You're not going to come to the table cold 22 on either of those. And then you're going to sort of 23 set the specifications of what you need your fuel to 24 accomplish to meet your design objectives, and you're 25 going to have to iterate somewhat.
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 1 But at the end of the day, when it comes 2 to regulatory review, we come in at the end where you 3 have a proposed design and a proposed fuel and you 4 need to be demonstrating that your fuel is qualified 5 for the range of conditions in your design that's 6 proposed. Is that what you're getting at?
7 DR. SCHULTZ: Yes, it is. You've 8 described it very well. But in that process, you're 9 going to need to rely upon a wide variety of all of 10 that experimental and evaluation program that's gone 11 before.
12 MS. CUBBAGE: Yes, yes. Both on the fuel 13 side and with the design, the broader design. And it 14 all has to come together in an integrated manner to 15 justify the safety. And it's a very complex problem, 16 no doubt.
17 MR. DRZEWIECKI: Yes. I do want to 18 highlight because like, some of those early steps, 19 some of those things are not things that the NRC has 20 always been, we haven't really been seeing some of 21 that data which is informing some of those design 22 optimization decisions.
23 DR. SCHULTZ: And perhaps setting up a 24 structure like this, and as you said at the very 25 outset, Tim, this hasn't been part of the NRC's 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 1 overall review process.
2 So, setting this up as an expectation 3 going forward with the advanced designs is really 4 important to do.
5 MS. CUBBAGE: Yeah, for sure.
6 DR. SCHULTZ: And should help.
7 MS. CUBBAGE: This is Amy Cubbage again.
8 I think we need to set those expectations and provide 9 predictability for applicants going forward such that 10 if they go through a multi-year fuel qualification 11 program, they know what the objectives need to be.
12 And also, our history more recently has 13 been in the LWR fuel. And you're talking about tweaks 14 and adjustments and they can start their design based 15 on a reference fuel and then they can later justify 16 upgrading to the latest new fuel bundle so it's more 17 of an evolution.
18 But this is a totally different ball game 19 we're in with these new designs.
20 (Simultaneous speaking.)
21 MEMBER KIRCHNER: This is Walt. Since you 22 actually put this up, is the expectation, is it 23 reasonable to convey to the applicants that the 24 expectations as highlighted here in yellow, especially 25 the second line, will it be part of what would be 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 1 expected in an application?
2 MS. CUBBAGE: Do you mean more broadly 3 than the fuel, or are you speaking --
4 MEMBER KIRCHNER: No, I'm just talking 5 about fuel. I'm reading the second row here in 6 yellow.
7 Fabrication of referenced fuel derived 8 from production supply sources irradiated to design 9 conditions and utilization of radiation in a 10 representative environment.
11 MS. CUBBAGE: That pretty much sums up 12 what we're trying to convey.
13 MEMBER KIRCHNER: That's the expectation.
14 CHAIRMAN PETTI: That's a proof test by 15 definition, I think.
16 MR. DRZEWIECKI: Yes. Now, we do want to 17 say that there is room to where perhaps you can 18 justify doing something different or you could use 19 something like a lead test program, something like 20 that in order to try to bootstrap stuff. But, yes.
21 CHAIRMAN PETTI: I mean, on the opposite 22 perspective, let's say you had a new clad that you 23 had. But the fuel meet in a pin clad system have been 24 through a lot of testing with the different cladding, 25 you know.
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 1 I don't think just irradiating the clad 2 alone would be enough to come in and say okay, we have 3 this old fuel with this old clad and then we just 4 irradiated the new clad over here. Look, it didn't do 5 anything.
6 I still think that integrated test at the 7 end is required. And I honestly think most people in 8 the fuel development business would agree with that.
9 It's the process that it takes to get you here that 10 there may be more than one path.
11 The path laid out in 2007 is a typical 12 experimental path. AFQ is more let's bring in more 13 modeling to see if we can accelerate getting to this 14 end state. But this end state is still, I think 15 really important from the regulatory perspective.
16 MR. DRZEWIECKI: Hey, Jordan, could you go 17 to the next slide, Slide 41? I just want to back up 18 Dr. Petti's statement. You know, this is the AFQ 19 process.
20 This is a figure from the AFQ paper. And 21 it's exactly right. They are not proposing to get rid 22 of that final step.
23 CHAIRMAN PETTI: Yes. I think this is a 24 very interesting discussion, because if you talk to 25 some of these AFQ modelers long before AFQ was a term, 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 1 and some of them have come from other industries.
2 And apparently, in other industries there 3 is a lot more separate affects testing and model 4 development in this integration and much fewer 5 integral tests. Whereas nuclear tends to have a 6 history of the other way around, where we jump to the 7 integral testing largely because of the complexity and 8 what we could do back in the 70s.
9 So, it's an interesting question as to 10 whether or not the paradigm that's used in other 11 technologies can work here and can accelerate the 12 process in the end.
13 DR. SCHULTZ: Tim, this is a very 14 important slide -- this is Steve again -- that really 15 does demonstrate how this could work, because I think 16 the structure that you've laid out in setting things 17 up fits very well with the overall process shown here.
18 MR. DRZEWIECKI: Thanks.
19 CHAIRMAN PETTI: And my recommendation 20 when you get into this NUREG is some of these figures 21 could be very useful in the document itself to help 22 people go from sort of an abstract requirements based, 23 which is how I read the document, to helping them 24 think about how the piece parts fit together.
25 DR. SCHULTZ: Yeah, what I was missing 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 1 before and trying to describe was that feedback loop 2 that you have in the Phase 2 diagram here between the 3 integral fuel testing and the separate effects 4 testing.
5 MR. DRZEWIECKI: I do want to highlight 6 that this is, okay, this figure here is from a paper 7 that was authored by Kurt Terrani and others as well 8 out of Oak Ridge National Laboratory.
9 I just wanted to highlight that, really 10 that they're not proposing it to move away from that 11 final step. But, yes.
12 DR. SCHULTZ: Understood.
13 CHAIRMAN PETTI: And, you know, the key 14 thing to me is, if you look at the history of fuels 15 work it's always something that wasn't thought about 16 that got the fuel design.
17 Looking in the rear view mirror you look 18 at it now and it's always easy. But the real question 19 is, how good are these models going to be to predict 20 something that you've not seen before?
21 And that's really, I think where it all 22 hinges.
23 MEMBER REMPE: So then, the actual time of 24 the test, the duration of the test and operational 25 performance comes into play big time. And the unknown 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 1 unknowns are the one thing I was wondering about when 2 I was looking at this White Paper too, Dave.
3 CHAIRMAN PETTI: Yeah, Phase 2 here could 4 be much longer if you end up, if stuff comes up that 5 you just didn't see. The real problem in fuel 6 qualification is not, this is the optimistic success 7 oriented schedule.
8 The problem usually is something happens 9 when you go to the first integral test or even a 10 partial integral test that was not foreseen, requires 11 you to go back and fix something and then start again.
12 And that's what kills the fuels. The 13 question is, today's tools, can they help make sure 14 you don't have to go backwards and iterate as much?
15 MEMBER REMPE: They have to be validated.
16 DR. SCHULTZ: Well, just sticking with 17 this for a moment more. Tim, you mentioned earlier 18 that if I look at the third box, Phase 3, where you 19 have the integral fuel fabrication and so forth, that 20 box looks a lot like what is the foundation of what 21 you've described today in terms of the regulatory 22 process.
23 And then the previous two boxes, Phase 1 24 and Phase 2, represent that area of development that, 25 as you indicated earlier with LWR fuels and so forth, 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 1 the NRC hasn't really been involved with.
2 And so, a program that looks like this 3 that incorporates involvement by the regulator as well 4 as industry could be very helpful so that by the time 5 industry gets to Phase 3, there is a lot better 6 understanding as to what has gone into the fuel 7 development and justification.
8 MS. CUBBAGE: Yeah, this is Amy Cubbage 9 again. I would just like to highlight that is one of 10 the areas that we strongly encourage pre-application 11 engagement well before an applicant is ready to come 12 to the NRC, so that we can have that involvement, both 13 in the plans for fuel qualification and in the 14 execution.
15 DR. SCHULTZ: That would be great. That 16 makes a lot of sense.
17 CHAIRMAN PETTI: Yeah. Also, I think, you 18 know, the yellow box, two to five years is extremely 19 optimistic. The hardest thing to do here is not the 20 actual test.
21 The testing takes a certain amount of 22 time, right? So, many neutrons on the target and to 23 hit the transient testing. But to stand up at 24 industrial scale a fuel vendor is not an insignificant 25 activity.
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 1 And probably it's starting in the blue 2 box. There's a little bit of overlap. That could be 3 two to three years longer than what they think there, 4 just because of specifics and specific technologies.
5 MS. CUBBAGE: And, Tim, this is Amy 6 Cubbage again. This is representative of AFQ goals, 7 right?
8 MR. DRZEWIECKI: That's right.
9 MS. CUBBAGE: This isn't necessarily 10 indicative of the, what we currently expect.
11 MR. DRZEWIECKI: It is not, it is not. I 12 mean, what okay, so this framework that's in the White 13 Paper, it was written from a perspective, again, we 14 typically engage at this final step. Will you have 15 integral fuel test data?
16 Now, in terms of this process in the 17 middle we are engaged with the AFQ group right now.
18 But again, we have engaged from a perspective that we 19 do expect to see this kind of integral data at the 20 end.
21 CHAIRMAN PETTI: Any other Members of the 22 Committee have comments before we ask for the public?
23 MEMBER BROWN: Yes, Dave. This is 24 Charlie.
25 CHAIRMAN PETTI: Go ahead.
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 1 MEMBER BROWN: I couldn't find my mic.
2 This is more of a technical question and I guess since 3 I'm not a statistician, that's why I'm asking it.
4 There are a number of places in this White 5 Paper, throughout this decomposition and composition 6 approach, where they make the statement that we may 7 not be able to get data due to the environmental 8 safety or economic needs associated with determining, 9 with obtaining the sufficient amount of data.
10 And then they go on to say, we will figure 11 out a way to use less data. I'm trying to integrate 12 that with some of the past experience before I left 13 Naval Reactors and figure out what do we mean by not 14 having enough data --
15 MR. DRZEWIECKI: Yes, so --
16 MEMBER BROWN: -- to be able to balance 17 stuff. I am not a statistician, and this sounded like 18 if it costs too much, we'll figure out a way to 19 determine some boundaries without having sufficient 20 data.
21 And that was a little bit disturbing. Not 22 a critical comment. It just seemed to be contrary.
23 MR. DRZEWIECKI: Yeah, I see what you 24 mean. And so, I would point to it's what we do now 25 for, you know, like rod ejection events or reactivity 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 1 induced accidents.
2 We have our fuel failure criteria, the 3 cladding failure criteria, what are due to over 4 temperature or PCMI. And we have some data there.
5 We may have, like, 20 some data points 6 maybe in the 30s. But that's not really enough to get 7 you to like a 95/95 type of a limit.
8 And so, what's typically done there is, 9 curves are drawn that we think are suitably 10 conservative but also reasonable. And so, but there 11 is not like a thorough statistical analysis done 12 there.
13 So, that's kind of the surrogate that 14 we're trying to get to there, because we recognize 15 that to get 59 or 100 points from tests that can be 16 destructive. Not only is it expensive, it also 17 creates waste and maybe there's things that just 18 aren't appropriate.
19 So, we've done it in the past and we think 20 we can do it in the future.
21 MEMBER BROWN: What do you do, just put 22 lines so you bound all of it?
23 I guess I am still struggling a little bit 24 with that understanding, if we're going to base the 25 transient performance or the accident performance 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 1 based on data points which are sparse. I mean it's --
2 MR. DRZEWIECKI: Yes, I mean I will say 3 it's done on a case by case basis. Certainly a 4 drawing a line which is bounding is one approach.
5 But based on what I've seen, like what 6 we've done per reactivity induced accidents, not 7 necessarily the case. Those curves are pretty 8 reasonable, slightly conservative, but not bounding.
9 However, we think, one safety case for 10 those is the fact that there is margin in the methods 11 themselves, the way that you analyze a reactivity 12 induced accident like a rod ejection. There are 13 conservative in those methods such that, you know, we 14 didn't want to pile on additional conservatism in the 15 number of counted failed fuel rods.
16 But that's what's done there. And so, I 17 guess my answer would be that it's really done on a 18 case by case basis.
19 We want to ensure that there is 20 reasonable, that it's conservative. But at that same 21 point, there's going to be some kind of judgment in 22 there. It's not purely objective.
23 MEMBER BROWN: Okay, thank you.
24 CHAIRMAN PETTI: Other comments? Okay.
25 Well, let's open the public line and see if there is 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 1 any members of the public that wanted to weigh in.
2 Okay, I don't hear anything.
3 MR. DRZEWIECKI: It was not unmuted. I 4 could -- that's the -- let me, it's still muted.
5 CHAIRMAN PETTI: Yeah, I see it's still 6 muted, yeah.
7 MR. DRZEWIECKI: I don't know who is 8 running the meeting, if they could unmute them or not.
9 CHAIRMAN PETTI: Derek, can you unmute 10 them?
11 MR. MOORE: Thomas, this is Scott. Can 12 you unmute the public line, please?
13 MS. CUBBAGE: And it's muted within Teams.
14 So, someone needs to I think hit star 6 on that line.
15 CHAIRMAN PETTI: Okay. It's unmuted. Any 16 comments from the public? I don't hear any.
17 So, Tim, could you just lay out again your 18 going forward schedule, how you see, you know, when 19 are you going to go out for comments and then when are 20 they going to come back?
21 MR. DRZEWIECKI: So, Jordan, perhaps --
22 DR. FELTUS: Hi. This is Madeline Feltus 23 from the Department of Energy. I have one question 24 for the group, if you can hear me.
25 Prototypical testing may not be available, 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 1 for instance, if we don't have a FAST reactor design 2 or if, you know, if we use the ATR, we don't get exact 3 conditions.
4 So, the question would be, besides 5 interval testing in a test reactor, would we still be 6 required to have demonstration reactors or some way to 7 test the reactor conditions before a commercial power 8 reactor could be built?
9 I want to make sure that we address some 10 of the questions that came in from the AFQ Working 11 Group about having testing in actual reactors as 12 mandatory.
13 MR. DRZEWIECKI: Well, I could say that 14 the way that the structure is written now, you know, 15 there would need to be some kind of data in order to 16 support the evaluation model and the safety case of 17 that fuel.
18 If there is some kind of, some kind of a 19 test, a distortion, like you mentioned, perhaps it 20 wasn't in the FAST spectrum, can you make an argument 21 that's okay? I believe that people have tried to make 22 that.
23 I'm not familiar with it myself. I 24 believe people have tried to make some of those 25 arguments, trying to use or do things to simulate a 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 1 FAST spectrum inside of something like ATR.
2 There is other options too. This was 3 written from a perspective that you were going to try 4 to satisfy 5043(e)(1) and have that data. There are 5 other options.
6 There is a prototype option which is out 7 there. You can also do other things as well. You can 8 do things like test assembly if you don't have high 9 burn up data.
10 In the absence of any data at all, we 11 would have to think about that. I think that would be 12 challenging.
13 CHAIRMAN PETTI: Okay. Tim, can you go 14 back to the schedule?
15 MR. DRZEWIECKI: Yes, yes, sorry. So, 16 yes, there was a schedule.
17 So, we -- I'm going to try to get the, as 18 far as the NUREG, to address comments to get that 19 through, I think, by I'll say this month and then 20 through OGC a couple weeks after that.
21 And for notice and comment, Jordan, do you 22 have the dates for the notice and comment period?
23 MR. HOELLMAN: Hey, Tim. This is Jordan 24 Hoellman. I don't have the exact dates, I guess. I 25 think we were shooting for May to release it for 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 1 public comment.
2 I wasn't sure how long it would take us to 3 address the comments volunteered from the AFQ Working 4 Group, or how long it would take for us to get those 5 incorporated. And then the NUREG process has its own, 6 you know, special process where you've got to go 7 through the office of the administration and things 8 like that.
9 So, we were targeting May for release of 10 the direct NUREG for public comment expecting the 60 11 day public comment period, and then we'll, you know, 12 address the public comments and come back to the full 13 committee here.
14 CHAIRMAN PETTI: Okay. Well, with that, 15 unless there's any final comments, I guess we're done.
16 So, I want to thank Tim and Amy and everybody else who 17 was involved.
18 And I think we enjoyed the discussion, 19 lots of interesting comments and questions and look 20 forward to the September meeting.
21 MS. CUBBAGE: Thank you. We appreciate 22 all the feedback.
23 (Whereupon, the above-entitled matter 24 went off the record at 3:34 p.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
Fuel Qualification (FQ) for Advanced Reactors (Draft White Paper)
ACRS Subcommittee Meeting February 2, 2021 1
Outline Introduction and Background Associated Regulations Activity affecting FQ guidance Nuclear Energy Innovation and Modernization Act (NEIMA)
Input to FQ assessment framework General Approach Scope of FQ Description of assessment frameworks Overview of FQ assessment framework Near term activity/next steps 2
Introduction Accelerated fuel Foreign qualification regulators (NEA/CNRA/WGSAR) (AFQ)
(Advanced mod-sim)
Advanced Advanced reactor reactor NEIMA fuel qualification stakeholders 3
Regulatory Aspects of Nuclear Fuel Qualification No requirements specific to nuclear fuel qualification Requirements on fuel qualification are provided by top level requirements attributed to the facility Design limits for normal operation and AOOs:
GDC/ARDC 10, Reactor design Accident acceptance criteria (Coolable geometry/Dose):
GDC 27/ARDC 26 - Reactivity control systems GDC/ARDC 35 - Emergency core cooling system 10 CFR 50.34(a)(1)(ii)(D), 10 CFR 52.47(a)(2)(iv), and 10 CFR 52.79(a)(1)(vi)
Natural phenomena (Seismic)
GDC/ARDC 2, Design bases for protection against natural phenomena Data - 10 CFR 50.43(e) - Demonstrate safety features 4
Regulatory Aspects of Nuclear Fuel Qualification
- Guidance
- NUREG-0800, Standard Review Plan
- Section 4.2, Fuel System Design
- Identifies acceptance criteria derived from know fuel failure/degradation mechanisms for light water reactor fuel
- ATF-ISG-2020-01
- Significant changes to fuel design must be assessed for potentially new failure/degradation mechanisms
- Reg Guide 1.233, Licensing Modernization
- Emphasis on risk - requires understanding of accident sequence consequences (i.e., source term) 5
FQ Activity NRC reviewed and approved:
EPRI-AR-1, "Uranium Oxycarbide (UCO) Tristructural Isotropic (TRISO) Coated Particle Fuel Performance," May 2019 ANL/NE-16/17, Rev. 1, "Quality Assurance Program Plan for SFR Metallic Fuel Data Qualification," May 2019 NRC supported activity:
MSR fuel qualification:
ORNL/LTR-2018/1045, "Molten Salt Reactor Fuel Qualification Considerations and Challenges," 2018 (ML18347A303)
ORNL/TM-2020/1576, "MSR Fuel Salt Qualification Methodology," 2020 (ML20197A257)
Source term:
SAND2020-0402, "Simplified Approach for Scoping Assessment of Non-LWR Source Terms," 2020 (ML20052D133)
INL/EXT-20-58717, "Technology-inclusive determination of mechanistic source terms for offsite dose-related assessments for advanced nuclear reactor facilities," 2020 (ML20192A250) 6
FQ Activity White paper assessment:
TerraPower, Advanced Fuel Qualification Methodology (ML20209A155, ML20310A278)
Additional papers expected in February White paper development:
General Atomics - Accelerated Fuel Qualification (AFQ)
NEA - Working Group on the Safety of Advanced Reactors (WGSAR)
Fuel Qualification Report 7
NEIMA SEC. 103. ADVANCED NUCLEAR REACTOR PROGRAM (c) REPORT TO INCREASE THE USE OF RISK-INFORMED AND PERFORMANCE-BASED EVALUATION TECHNIQUES AND REGULATORY GUIDACNE 8
FQ Input - Literature Journal of Nuclear Materials (JNM 2007) Paper JNM 2020 Paper 9
Stakeholder Input
- Foreign regulatory authorities via WGSAR:
- Canada, France, Germany, IAEA, Italy, Russia, and UK
- Domestic advanced reactor stakeholders through stakeholder meetings
- UCS, USNIC, SNC, Kairos, GA, INL, public
- NRC internal stakeholders through the Technical Advisory Group on Fuel (TAG-F)
- NRR (new and operating reactors), RES, NMSS
- Vendor input through AFQ working group 10
Outline Introduction and Background Associated Regulations Activity affecting FQ guidance Nuclear Energy Innovation and Modernization Act (NEIMA)
Input to FQ assessment framework General Approach Scope of FQ Description of assessment frameworks Overview of FQ assessment framework Near term activity/next steps 11
FQ Framework - Scope Broad interpretation of fuel qualification (many aspects of nuclear safety are impacted by the fuel)
Neutronic performance Thermal-fluid performance (e.g., margin to critical heat flux limits)
Fuel transportation and storage Need to restrict the scope of the report The scope of this report focuses on the identification and understanding of fuel life limiting and degradation mechanisms that occur as a result of irradiation during reactor operation.
12
Assessment Framework Development of a generic assessment framework for fuel qualification:
Top-down approach used to decompose the top level goal of fuel is qualified into lower level supporting goals Lower level supporting goals are further decomposed until clear objective goals are identified that can be satisfied with direct evidence NRC has used assessment framework approach to evaluate thermal-margin models (e.g., critical heat flux
- see NUREG/KM-0013)
Significant reduction in review time Comprehensive/transparent review 13
FQ Framework - Other Considerations Definition of fuel qualification (from JNM 2007)
The objective of nuclear fuel qualification is the demonstration that a fuel product fabricated in accordance with a specification behaves as assumed or described in the applicable licensing safety case, and with the reliability necessary for economic operation of the reactor plant Clarify safety case The role of nuclear fuel in the safety case can vary significantly between different reactor designs (e.g. TRISO fuel contains fission product barriers within the fuel itself) 14
Outline Introduction and Background Associated Regulations Activity affecting FQ guidance Nuclear Energy Innovation and Modernization Act (NEIMA)
Input to FQ assessment framework General Approach Scope of FQ Description of assessment frameworks Overview of FQ assessment framework Near term activity/next steps 15
FQ Assessment Framework: Goal Goal: Fuel is qualified for use
= High confidence exists that the fuel fabricated in accordance its specification will perform as described in the applicable licensing safety case Goal: Fuel is qualified for use A fuel manufacturing specification controls the key Safety criteria can be fabrication parameters that satisfied with high significantly affect fuel confidence [G2]
performance [G1]
16
G1: Manufacturing Specification A fuel manufacturing specification controls the key fabrication parameters that significantly affect fuel performance [G1]
Microstructure attributes Key dimensions and Key constituents are for materials within the tolerances of fuel specified with fuel component are components are allowance for specified or otherwise specified [G1.1] impurities [G1.2]
justified [G1.3]
17
G2: Safety Criteria Safety criteria can be satisfied with high confidence [G2]
Margin to design limits can be Margin to radionuclide demonstrated under conditions release limits under accident Ability to achieve and of normal operation, including conditions can be maintain safe shutdown can the effects of anticipated demonstrated with high be assured [G2.3]
operational occurrences with confidence [G2.2]
high confidence [G2.1]
10 CFR 50.34(a)(1)(ii)(D) GDC/ARDC 2 GDC/ARDC 10 10 CFR 52.47(a)(2)(iv) GDC 27/ARDC 26 10 CFR 52.79(a)(1)(vi) GDC/ARDC 35 18
G2.1: Design Limits for Normal and Anticipated Operational Occurrences Margin to design limits can be demonstrated under conditions of normal operation, including the effects of anticipated operational occurrences with high confidence [G2.1]
An evaluation model is available to assess fuel performance The fuel performance envelope against design limits to protect is defined [G2.1.1] against fuel failure and degradation (i.e., life-limiting) mechanisms [G2.1.2]
Note: The fuel performance envelope specifies the environmental conditions and radiation exposure that the fuel is expected to encounter. The envelope is typically specified by fuel designers and provides constraints on the design of the reactor and associated systems.
19
Evaluation Model (EM)
Assessment Framework Goal: The evaluation model is acceptable The evaluation model contains The evaluation model has the appropriate modelling been adequately assessed capabilities against experimental data
[EM G1] [EM G2]
20
EM G1: Modeling Capabilities The evaluation model contains the appropriate modelling capabilities
[EM G1]
The evaluation model is The evaluation model is The evaluation model is capable of modelling capable of modelling capable of modelling the material of the the material of the fuel the geometry of the necessary physics for and associated fuel [EM G1.1] fuel performance environment [EM G1.2]
[EM G1.3]
Note: Physics modeling is expected to have sufficient physics models to address fuel failure mechanisms. An example means of justifying knowledge of failure mechanisms is the use of an expert panel to develop a phenomena identification and ranking table (PIRT). Ultimately, the evaluation model is assessed under EM G2.
21
EM G2: Assessment The evaluation model has been adequately assessed against experimental data
[EM G2]
The evaluation model has demonstrated the ability to Experimental data used for predict fuel failure and assessment is appropriate degradation mechanisms over
[EM G2.1]
the test envelope
[EM G2.2]
22
EM G2.2: Demonstrated Ability over Test Envelope The evaluation model has demonstrated the ability to predict fuel failure and degradation mechanisms over the test envelope
[EM G2.2]
Evaluation model error Evaluation model The evaluation model is quantified through error is determined Sparse data regions is restricted to use assessment against throughout the fuel are justified within its test experimental data performance envelope [EM G2.2.3] envelope
[EM G2.2.1] [EM G2.2.2] [EM G2.2.4]
23
Experimental Data (ED)
Assessment Framework Goal: Experimental data used for assessment is appropriate Assessment data is Data has been collected Experimental data Test specimens are independent of data over a test envelope have been representative of used to develop/train that covers the fuel accurately measured prototypical fuel the evaluation model performance envelope
[ED G3] [ED G4]
[ED G1] [ED G2]
Note: The types of test that should be considered in the test envelope include (1) steady-state integral testing of the fuel system in a prototypical environment, (2) high power and undercooling tests to address AOO conditions and to assess design margin, (3) power ramp testing to assess fuel performance during anticipated power changes, and (4) design basis accident tests to establish margin to fuel breach and contribution to source term under accident conditions 24
ED G3: Data Measurement Experimental data have been accurately measured
[ED G3]
Experimental data accounts for The test facility has an Experimental data is sources of experimental appropriate quality collected using established uncertainty, including assurance program measurements techniques instrumentation uncertainty
[ED G3.1] [ED G3.2]
[ED G3.3]
Note: It is expected that the quality assurance program would address issues such as malfunctioning/broken instrumentation.
25
ED G4: Test Specimens Test specimens are representative of the fuel design
[ED G4]
Test specimens are fabricated Distortions are justified and consistent with the fuel accounted for in the manufacturing specification experimental data
[ED G4.1] [ED G4.2]
Note: Differences may be Note: Compare with G1: associated with fabrication Manufacturing specification techniques, dimension, composition, and environment.
26
Summary of FQ Assessment Framework Supported by two additional assessment frameworks Evaluation Models Experimental Data A total of 60 terminal goals 11 in the main FQ Assessment Framework 2 x (14 in the Evaluation Model Assessment Framework) 3 x (7 in the Experimental Data Assessment Framework) 27
Outline Introduction and Background Associated Regulations Activity affecting FQ guidance Nuclear Energy Innovation and Modernization Act (NEIMA)
Input to FQ assessment framework General Approach Scope of FQ Description of assessment frameworks Overview of FQ assessment framework Near term activity/next steps 28
Near Term Activity
- Exercise framework
- Contract with Argonne and Idaho National Laboratory to evaluate a generic metal fuel design (e.g., EBR-II Mark-V/VA)
- Consistent with approach for Aurora COL
- Reliance on EBR-II data 29
Next Steps
- Convert report into a regulatory document (e.g. NUREG)
- Address/incorporate volunteered comments
- OGC review
- Notice and comment
- ACRS Full Committee - September 2021 30
Backup Slides 31
G2: Safety Criteria Safety criteria can be satisfied with high confidence [G2]
Margin to design limits can be Margin to radionuclide demonstrated under conditions release limits under accident Ability to achieve and of normal operation, including conditions can be maintain safe shutdown can the effects of anticipated demonstrated with high be assured [G2.3]
operational occurrences with confidence [G2.2]
high confidence [G2.1]
10 CFR 50.34(a)(1)(ii)(D) GDC/ARDC 2 GDC/ARDC 10 10 CFR 52.47(a)(2)(iv) GDC 27/ARDC 26 10 CFR 52.79(a)(1)(vi) GDC/ARDC 35 32
G2.2: Radionuclide Release Limits Margin to radionuclide release limits under accident conditions can be demonstrated with high confidence [G2.2]
Radionuclide retention Criteria for barrier degradation Radionuclide retention The fuel performance requirements of the and failure under accident and release behavior of envelope is defined fuel under accident conditions (e.g., PCMI and high the fuel matrix under
[G2.1.1] conditions is enthalpy cladding failure, accident conditions is specified [G2.2.1] temperature induced reactions modeled conservatively and phase transformations) are [G2.2.3]
suitably conservative [G2.2.2]
33
G2.2.2: Criteria for Barrier Degradation Criteria for barrier degradation and failure under accident conditions (e.g., PCMI and high enthalpy cladding failure, temperature induced reactions and phase transformations) are suitably conservative [G2.2.2]
Criteria are shown to provide conservative Experimental data is prediction of barrier appropriate degradation and failure [G2.2.2(b)]
[G2.2.2(a)]
34
G2.2.3: Conservative Modeling Radionuclide retention and release behavior of the fuel matrix under accident conditions is modelled conservatively [G2.2.3]
Radionuclide transport model is shown to provide conservative prediction of Experimental data is radionuclide retention and appropriate release behavior of fuel [G2.2.3(b)]
matrix
[G2.2.3(a)]
Note: Testing at environmental conditions consistent with accident conditions is expected (e.g., elevated fuel temperatures) 35
G2.3: Safe Shutdown Ability to achieve and maintain safe shutdown can be assured
[G2.3]
Maintaining coolable geometry Control element insertion can under accident conditions can be demonstrated with high be demonstrated with high confidence [G2.3.2]
confidence [G2.3.1]
36
G2.3.1: Maintaining Coolable Geometry Maintaining coolable geometry under accident conditions can be demonstrated with high confidence [G2.3.1]
Phenomena are identified that Criteria for maintaining coolable Criteria are shown to provide could cause a loss of coolable geometry under accident conservative prediction of geometry (e.g. fuel melt, fuel conditions (e.g., fuel dispersal) coolable geometry loss fragmentation, cladding ductility) are supported by quality mechanisms [G2.3.1(b)]
[G2.3.1(a)] experimental data [G2.3.1(c)]
37
G2.3.2: Control Element Insertion Control element insertion can be demonstrated with high confidence [G2.3.2]
Criteria are provided that An evaluation model is ensure that the control available to assess geometry element insertion path is not changes as a result of normal obstructed during conditions of operation and accident normal operation or accident conditions [G2.3.2(b)]
conditions [G2.3.2(a)]
38
SRP vs White Paper NUREG-0800 White Paper Safety Case Implicitly assumed to be similar Flexible - data requirement is to a traditional LWR (i.e., limited commensurate with assumed consideration of fission product contribution to source term retention within fuel)
Fuel failure mechanisms Fuel is evaluated against known Relies on evaluation model fuel failure mechanisms for LWR assessment to identify important fuel fuel failure mechanisms Criteria for manufacturing Not explicitly stated, but Specification of key parameters manufacturing dependent failure (geometry, composition, and criteria are provided in associated microstructure) identified as guidance (RG 1.236) objective criteria 39
Test Based FQ (JNM 2007)
AFQ (JNM 2020) 41