ML23186A068

Transcript of the Advisory Committee on Reactor Safeguards - Accident Analysis Thermal Hydraulics - Global Nuclear Fuels LANCR02 Topical Reports, June 6, 2023, Page 1-44 (Open)

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Official Transcript of Proceedings

NUCLEAR REGULATORY COMMISSION

Title:

Advisory Committee on Reactor Safeguards Accident Analysis Thermal Hydraulics Open Session

Docket Number: (n/a)

Location: teleconference

Date: Tuesday, June 6, 2023

Work Order No.: NRC-2426 Pages 1-26

NEAL R. GROSS AND CO., INC.

Court Reporters and Transcribers 1716 14th Street, N.W.

Washington, D.C. 20009 (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 W ASHINGTON, 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 THERMAL-HYDRAULICS ACCIDENT ANALYSIS SUBCOMMITTEE

8 + + + + +

9 OPEN SESSION

10 + + + + +

11 TUESDAY,

12 JUNE 6, 2023

13 + + + + +

14 The Subcommittee met via hybrid in-person

15 and video-teleconference, at 1:00 p.m. EDT, Jose

16 March-Leuba, Chairman, presiding.

17

18 COMMITTEE MEMBERS:

19 JOSE MARCH-LEUBA, Chair

20 RONALD G. BALLINGER, Member

21 VICKI BIER, Member

22 CHARLES H. BROWN, JR., Member

23 VESNA DIMITRIJEVIC, Member

24 GREGORY HALNON, Member

25 WALT KIRCHNER, Member

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1 DAVID PETTI, Member

2 JOY L. REMPE, Member

3 MATTHEW SUNSERI, Member

4

5 DESIGNATED FEDERAL OFFICIAL:

6 MIKE SNODDERLY

7

8 ALSO PRESENT:

9 KENT HALAC, GE

10 JOHN HANNAH, GNF

11 SCOTT KREPEL, NRR

12 MATHEW PANICKER, NRR

13

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1 TABLE OF CONTENTS

2 Opening Remarks, Jose March-Leuba, Chair 4

3 Discussion of GNF Topical Reports on

4 LANCR02 Computer Programs for

5 Evaluating Fuel Lattices, John

6 Hannah, GNF 7

7 Staff's Evaluation of GNF Topical Reports,

8 Matthew Panicker, NRR 20

9 Opportunity for Public Comment

10 (No public comment)

11 Adjourn 26

12

13

14

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25

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

2 1:00 P.M.

3 CHAIR MARCH-LEUBA: The meeting will now

4 come to order. This is a meeting of the Accident

5 Analysis Thermal Hydraulics Subcommittee. I am Jose

6 March-Leuba, the SC chair.

7 In addition to in-person attendance at NRC

8 headquarters, the meeting is broadcasted via MS Teams.

9 Members in attendance are Ronald Ballinger, Vicki

10 Bier, Charles Brown, Vesna Dimitrijevic, Greg Halnon,

11 Walter Kirchner, David Petti, Joy Rempe, and Matthew

12 Sunseri.

13 Today, we are reviewing topical report

14 NEDE-33935P, Revision 0, by Global Nuclear Fuel

15 Americas entitled LANCR02/PANAC11 application

16 methodology, and two associated methodology

17 qualification reports.

18 These reports support a combined use of

19 the LANCR02 and PANAC11 codes for modeling neutronics

20 and thermal hydraulic BWR core physics.

21 Portions of our meeting will be closed to

22 the public to protect GNF priority information. We

23 have not received requests to provide comments, but we

24 have an opportunity for public comments before the

25 beginning of the closed session of the meeting.

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1 The ACRS was established by a statute and

2 is open by the Federal Advisory Committee Act, FACA.

3 As such, the committee only speaks to its published

4 letter reports.

5 The rules for participation in all ACRS

6 meetings were announced in the Federal Register on

7 June 13, 2019. The ACRS section of the U.S. NRC

8 public work site provides our charter, bylaws,

9 agendas, letter reports, and full transcripts for the

10 open portions of all full and subcommittee meetings,

11 including the slides presented there.

12 The Designated Federal Official today is

13 Michael Snodderly.

14 A transcript of the meeting is being kept.

15 Therefore, speak into the microphones clearly and

16 state your name for the benefit of the court reporter.

17 And if you are in a conference room with multiple

18 people on the line, just remember to identify yourself

19 regularly for the accuracy of the transcript.

20 Please keep all your electronics and the

21 microphone on mute when not being used.

22 We are now ready for the GNF presentation.

23 Kent Halac of General Electric Hitachi will present

24 some opening remarks and introduce the GNF presenters.

25 Remember, this is the open session of the

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1 meeting. Questions that may need proprietary

2 information should be discussed in the closed session.

3 Kent?

4 MR. HALAC: Thank you. This is Kent

5 Halac, General Electric. We're representing Global

6 Nuclear Fuels. I brought with me John Hannah,

7 principal engineer in our Advanced Methods Group.

8 Thank you for having us today. We have some

9 interesting material that pushes our technology

10 forward and enables increased enrichment which is one

11 of the objectives of these updates.

12 We're here to answer any questions you may

13 have about the technology. And just note that LANCR

14 and PANAC are both approved technologies, and this is

15 the combination of LANCR with PANACEA for the

16 application method and we're going to be talking about

17 LANCR02 updates to enable increased enrichment.

18 With that, I'll move to John.

19 MR. HANNAH: Thanks, Kent. This is John

20 Hannah as Kent introduced --

21 CHAIR MARCH-LEUBA: Sorry, there is a very

22 narrow field of view for the mic. If you cannot hear

23 yourself on --

24 MR. HANNAH: Then you can't hear. Okay

25 CHAIR MARCH-LEUBA: -- you're not talking

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1 --

2 MR. HANNAH: I'm going to try again.

3 Okay, now I can hear me.

4 This is John Hannah from Global Nuclear

5 Fuels as Kent suggested. So I am here representing

6 the team that worked on this material. There was a

7 good number of us to advance this forward, so I'm

8 looking forward to talking about it today.

9 Slide, Kent.

10 So just a few introductory remarks in this

11 part of the session. We'll go a little deeper in the

12 closed session, talk about backgrounds, the drivers

13 and approach associated with these licensing topical

14 reports which you'll hear me refer to as LTRs

15 sometimes. Kind of why we developed them and what we

16 were trying to do when we did. And then what the

17 current status of them is.

18 Okay, so from a high level perspective and

19 background, right now, TGBLA06 and PANAC11 is GNF's

20 approved core simulator that's in use today across the

21 BWR fleets, boiling water reactor fleet. TGBLA06, all

22 lattice business codes, application range is limited

23 with respect to a next phase of fuel development, so

24 where we're trying to head to support ATF objectives,

25 be those higher enrichments, different clad types.

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1 It's not something that right now TGBLA has approved

2 to evaluate.

3 We do have LANCR02 which is approved from

4 a model and qualification perspective which is our

5 more advanced lattice physics code and does have the

6 approval to evaluate some of these features. And so

7 the main purpose of putting together the revisions to

8 the LANCR topical report and the combined LANCR/PANAC

9 topical report was to enable their use together as an

10 approved core simulator to evaluate these new spaces.

11 To that end, the driver really is to

12 expand the core simulator application range when we're

13 using LANCR as a new lattice physics solver as opposed

14 to TGBLA, so LEU+ is one of the main drivers for that,

15 looking to be able to evaluate fuel enriched between

16 5 and 10 percent in U235.

17 In addition, there is currently in

18 operation fuel designs that are 11 by 11 in nature and

19 TGBLA has in some limitations associated with that and

20 LANCR does not. And so it's another driver for moving

21 in that direction.

22 CHAIR MARCH-LEUBA: Remember that we are

23 in open session and you probably can answer better in

24 a closed session, but anything you can say for the

25 public it helps on the transcript.

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1 Can you tell us anything about GE plans to

2 use LEU+, anything above 5 percent, anything in the

3 near future, 20 years from now?

4 MR. HALAC: This is Kent speaking. I can

5 speak to that. We have already put in an application

6 1097 related to the fuel fabrication facility to

7 increase the plant to eight percent weight enrichment.

8 And we -- you know, the first step is getting our

9 methods in line and our plant ready to fabricate. The

10 next step after that would be lead test assemblies.

11 So this work here would enable us to analyze and

12 deliver lead test at some reactors.

13 CHAIR MARCH-LEUBA: And I know this may be

14 sensitive, you were talking 6 months or 20 years?

15 Neither, right?

16 MR. HALAC: Yes, neither is correct. But

17 I would say it's most near term for us in the ATF

18 programs. We use ATF as an umbrella for coated

19 claddings; iron, aluminum, chromium claddings. And

20 we've also married the benefits side which would be

21 increased enrichment with high burnup. And of all

22 those things for us the most near term would be LEU+.

23 CHAIR MARCH-LEUBA: Okay, thank you.

24 MR. HALAC: Sure. So going forward, the

25 purpose as I said for moving to LANCR is to kind of

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1 enable these new areas to be evaluated. In addition,

2 we're taking the opportunity to update the core

3 simulator approval basis. That's one of the big

4 drivers that's made our group very interested.

5 The approval basis for TG1PANAC expands

6 across several decades and a lot of different topic

7 reports. And there's an opportunity to clarify some

8 of that and make it easier to incrementally improve

9 going forward and so we've made a big effort to kind

10 of do that in this -- to enable that in this

11 submittal, trying to make minimal changes to what's

12 approved in the simulator space right now, but

13 clarifying how things work today, how uncertainties

14 are quantified, and basically putting together one

15 report that we can launch from going forward to

16 improve the way that we have evaluated the core.

17 CHAIR MARCH-LEUBA: I have seen -- again,

18 we are in open session. There are some processes to

19 modify the approval if you have small changes with

20 respect to the probe. Can you address some of these?

21 I'm trying to place these ideas in the public

22 transcript before we address them properly in the

23 closed session.

24 MR. HANNAH: Yes, there are some --

25 CHAIR MARCH-LEUBA: Keep it high level,

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1 non-proprietary.

2 MR. HANNAH: Understand, right, yes. In

3 LANCR, there is some -- there's a section that's

4 dedicated to describing updates that are allowable

5 that we modeled similarly in the LANCR-PANAC topical

6 report to try to lay out basically a foundation that

7 explains when you make or change kind of what the

8 definition of what that change is, what it requires

9 you to do and then how you're going to communicate

10 that with the regulatory body so that there's

11 agreement in the fronts what different changes mean

12 and what approval bases are required in an attempt to

13 make the approved -- make approval paths more certain

14 for everyone.

15 CHAIR MARCH-LEUBA: I try to think at the

16 lower level, so this is something equivalent to 10 CFR

17 50.59, in a sense that you will have to document your

18 changes. You will make a decision that this does not

19 require staff review. And then the staff can comment

20 on the methodology. Is that more or less what the

21 process will be?

22 MR. HANNAH: I would say that's one of the

23 outcomes of some of the update processes we define,

24 but some of the update processes I'm comfortable

25 saying, explicitly say if you do this, you have to

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1 resubmit. And so it's trying to say for the different

2 levels of changes what's going to be required so that

3 there's less ambiguity.

4 CHAIR MARCH-LEUBA: You're always allowed

5 to submit. The question is specifying what you don't

6 have to. Unfortunately, we all know you are in the

7 receiving end and it take 18 months, 2 years for any

8 approvals, so if you can avoid that by having an

9 agreement, a good bounder, a good box to stay inside

10 of that, we can save 2 years of review on 900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> of

11 cost is a positive direction.

12 MR. HANNAH: We agree.

13 MEMBER KIRCHNER: To follow on Jose's --

14 this Walt Kirchner -- Jose's point. I'm just guessing

15 your methodologies previously were limited to five

16 percent or less enrichment.

17 MR. HANNAH: Correct.

18 MEMBER KIRCHNER: And then the specific

19 cladding as well?

20 MR. HANNAH: Yes, the intent will be for

21 more exotic cladding materials, then LANCR would be

22 the solution. That's right.

23 MEMBER KIRCHNER: Right.

24 MR. HALAC: This is Kent. I just wanted

25 to add one more piece of information. We do a

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1 technology update every year between the staff and GNF

2 and during that update, we will talk about any and all

3 methodology changes so that there is an open line of

4 communication and that our standing of what is

5 happening, so that there is no misunderstandings about

6 changes being done without people understanding what

7 to do.

8 CHAIR MARCH-LEUBA: I may be using the

9 wrong term. Is this part of the GSTAR program?

10 Your mic --

11 MR. HALAC: Yes, we have hooks in GSTAR

12 for say, like, use programs that require us to provide

13 updates at the GNF technology updates, so yes, GSTAR

14 is part of the equation.

15 CHAIR MARCH-LEUBA: Thank you.

16 MR. HANNAH: So the approach which we at

17 hinted at bit, for some of what's on here, but first

18 for LANCR, it's important to note that there already

19 is an approval basis for revision 3 of the model and

20 qualification topical reports. And so what we're

21 doing here is relatively limited in scope for those

22 documents. We're looking to expand the core critical

23 benchmarking enrichment range to support the increase

24 enrichment from five to ten percent.

25 Updating the qualification basis, back

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1 when we originally submitted this, the benchmarking

2 was based against MCNP5. We're moving to MCNP6.2 and

3 then an improved version of that based on some

4 improvements that Los Alamos has basically recommended

5 that isn't yet in 6.2.

6 And then we're also implementing some

7 targeted model improvements that were informed based

8 on extensive benchmarking. So we basically pushed the

9 LANCR cross sections all the way through into the core

10 simulator, did our performance demonstrations and our

11 uncertainty quantifications, and used those results to

12 inform to ourselves where differences were being

13 exhibited compared to our current versions of codes.

14 And that helped us determine where we wanted to go and

15 try to implement some improvements in LANCR.

16 CHAIR MARCH-LEUBA: And once more for the

17 public transcript in case somebody has to read it,

18 this is part of the proprietary, but the benchmark set

19 that you guys used to validate this is very extensive.

20 I don't want to say the numbers. You may want to say

21 the numbers. I don't know if it's proprietary. But

22 it's very extensive.

23 MR. HANNAH: Yes, it's a large set of

24 cases. So going forward then so after the LANCR

25 updates, we went to create the LANCR and PANAC

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1 application LTR. There were four elements of that

2 that are important to --

3 MEMBER BROWN: Can I interrupt?

4 MR. HANNAH: Of course, yes.

5 MEMBER BROWN: I'm not a thermal-

6 hydraulics guy. I used to have to deal with this all

7 the time in my old job, 20 years ago in the Navy, we

8 had the analysis and we used to use Monte Carlo as

9 well, and I remember how we used to update the Monte

10 Carlo standards as we went. They were based on

11 experimental data. Is that -- when you go from 5 to

12 6.2 what benchmarks does the Monte Carlo use?

13 Hopefully, it's experimental data that you do that

14 with?

15 MR. HANNAH: That's right, yes. So I'm

16 comfortable saying in the public session even too,

17 right? So the concept of benchmarking LANCR, you

18 can't just go code to code against Monte Carlo basis.

19 MEMBER BROWN: I was hoping you would say

20 that.

21 MR. HANNAH: Yes, that gets connected to

22 the Monte Carlo code and the underlying cross sections

23 that are basically used in Monte Carlo and LANCR, get

24 benchmarked against cold critical benchmarks from a

25 criticality perspective and gamma scans for a pen

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1 power distribution.

2 MEMBER BROWN: Okay, so you've got actual

3 data that you can then validate Monte Carlo against

4 within some uncertainty bands?

5 MR. HANNAH: That's right. It's the

6 connected piece in between the actual LANCR and the

7 experiments because you can't do the experiments

8 directly into 2D lattice physics.

9 MEMBER BROWN: The second question was in

10 some of your documents, I didn't see it in these

11 slides and presume this is probably not proprietary,

12 but wasn't one of the purposes of this in order to

13 achieve higher burnups for your fuel as well? It was

14 in one of the topical reports.

15 MR. HANNAH: In fact, for LANCR and PANAC,

16 an increase in the burnup range isn't something that

17 we were pursuing. LANCR was already approved up to a

18 burnup that is bounding of what we need.

19 MEMBER BROWN: Okay, so the purpose of

20 this then is not to go another step forward. That

21 would be another process that you would do later then.

22 MR. HANNAH: Right, the nuclear methods in

23 the core simulator are not perceived to be an obstacle

24 to higher burnups. There are other areas where that

25 will be necessary.

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1 MEMBER BROWN: Thank you.

2 MR. HANNAH: So for LANCR and PANAC

3 application LTR, to enable it to be a foundation for

4 future change, we wanted to kind of document four

5 elements: defining the applicable methodologies

6 explicitly, kind of state what it is that these codes

7 are doing and how they do it; clarifying,

8 consolidating the uncertainty quantification

9 approaches which had been scattered across a number of

10 different topical reports in the past, so the intents

11 here was to make that more streamlined for users and

12 for changing the future; demonstrating performance of

13 the codes, against a broad set of actual operational

14 data; and then establishing update metrics which we

15 just kind of hinted at a moment before, update

16 mechanics to say precisely.

17 So the last thing just to point out the

18 current status just to give you an idea of where we've

19 been and where we're going, we started work on this

20 back in early 2020 as far as the latest iteration of

21 LANCR and PANAC. The actual work on LANCR goes back

22 much farther, way back into the -- before 2010. And

23 the approval of Revision 3 was in the 2015-16 time

24 frames. We're picking this back up now as driven by

25 the desire to move to fuel features that ATF enables

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1 like LU+. So we picked that back up early 2020.

2 Created the licensing topical reports. Issued them

3 for review in late 2021. We've been going through

4 review cycles since that time. There was an audit with

5 RAIs and RAI responses in the middle of 2022, which

6 led us to the ACRS meeting which we're at today. And

7 we're moving forward from there.

8 We believe we're on track for issuance of

9 an approved version of these LTRs by the end of 2023.

10 It's noted here because it's relevant that the final

11 approval of a supplement for this, Supplement 1, which

12 is the implementation of LANCR and PANAC and the

13 downstream methods is also happening in parallel

14 because you approved the core simulator and LANCR as

15 the underlying cross section, but then you need to

16 actually push that into your system codes and do

17 safety analyses and you need to understand the

18 qualification basis remains adequate or the

19 uncertainties that you're using are still applicable.

20 So that effort is ongoing. And we expect to try to

21 complete that around mid-2024 and that's what would

22 enable this in productions.

23 CHAIR MARCH-LEUBA: Completed the review

24 or complete the topical report?

25 MR. HANNAH: Complete the review. So the

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1 topical report has been submitted and we're through

2 some review phases of it, so that's an end state for

3 approval ideally.

4 CHAIR MARCH-LEUBA: Thank you.

5 MR. HANNAH: That's all I have.

6 CHAIR MARCH-LEUBA: Mike, do we have the

7 staff on line? So is Scott Krepel on line? I believe

8 Scott was going to produce some introductory remarks.

9 MR. KREPEL: (Speaking through an

10 interpreter) Can everyone hear me?

11 CHAIR MARCH-LEUBA: Yes, we can. We can

12 see you.

13 MR. KREPEL: Okay, great. I'm Scott

14 Krepel. I'm speaking through a sign language

15 interpreter. I'm the Branch Chief for the Nuclear

16 Methods and Fuel Analysis Branch with which is the

17 branch within the technical reviewers like Matthew who

18 did the review.

19 I am happy to have my staff present the

20 results of the review of these three topical reports

21 for LANCR. As you, I'm sure, are already aware, this

22 supports ATF-related activities since LANCR would be

23 approved for higher than five percent -- five weight

24 percent U235.

25 And I think that GEH and the staff worked

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1 well together to address all of the issues and get

2 them resolved satisfactorily including some last-

3 minute things that came up that will be discussed at

4 a later point during the presentation.

5 So I just wanted to give those remarks and

6 thank you for your time.

7 CHAIR MARCH-LEUBA: Thank you, Scott. So

8 I guess we move to Matthew Panicker to make the open

9 session interaction by the staff.

10 MR. PANICKER: I am Matthew Panicker. I am

11 a member of the Nuclear Materials and Fuel Analysis

12 Group in the Division of Safety System of NRI. And

13 this is a short presentation open to the public to the

14 ACRS today.

15 Next slide. Short list of topics covered

16 in the open session in relation to the background.

17 Review based on regulatory evaluation and review of

18 the guidance. It mainly is about NEDC-33935 topical

19 report which is LANCR02, PANAC11 application

20 methodology and early on I have a slide on short

21 summary and conclusions by the staff.

22 Next slide. The Global Nuclear Fuels

23 Americas updates its nuclear methods to enable lessons

24 and limits. The three TRs are the main, NEDC-33935

25 Revision 0, application methodology and the

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1 supporting topical reports are NEDC-33376P LANCR2

2 physics model and NEDC-33377P, Revision 4, lattice

3 physics model qualification reports.

4 The qualification reports consist of

5 figures to verify the cross sections and also some

6 test cases.

7 Next slide, please. The regulatory

8 evaluation is then based on GDC10 and Section 50.34.

9 (Unintelligible) requires licensees to perform safety

10 analysis.

11 And most of the new guidance is coming out

12 of Section 4.3 Nuclear Design of NUREG-0800 Standard

13 Review Plan for review of safety analysis report for

14 nuclear power plants. The list of areas of guidance

15 are listed in the closed session.

16 Next slide, please. NEDC-33935

17 Application methodologies applied to various fuel

18 designs approved for evaluation with LANCR02. LANCR02

19 is a lattice physics code that is used to process

20 nuclear data for use in the downstream analysis

21 methods. PANAC11 is the static evaluation couple

22 nuclear thermal hydraulic review program.

23 (Unintelligible) boiling water reactor code exclusive

24 of the external flow loop.

25 Next slide, please. A summary of the

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1 (unintelligible) and test cases (unintelligible) 6.2

2 qualification. There is also a section on performance

3 evaluation through compression qualifications and the

4 TR establishes guidelines for future updates for

5 normal and uncertainty ranges.

6 Next slide, please. The staff reviewed

7 all the TRs submitted for review. Staff reviewed the

8 methodology for efficacy demonstration and uncertainty

9 quantification. They reviewed the model distribution,

10 topical report and quantification topical report and

11 models were included in the code to predict the level

12 of physical processes for lattice physics analysis.

13 The results of this quantification or

14 qualification analysis just confirmed the

15 applicability of the latest ENDF/B-VII.0 cross

16 sections to analyze BWR.

17 Staff reviewed the LANCR02 model, the

18 LANCR02 model qualification, and LANCR02 application

19 methodology TR against acceptance criteria specified

20 in SRV 4.3, of the SRV which is titled nuclear design.

21 That is my last slide for this.

22 CHAIR MARCH-LEUBA: Thank you, Matthew.

23 It's not on the slide, but again for the open

24 transcript for the record, it is the intention of the

25 staff to issue a safety evaluation report approving

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1 this methodology for use in future applications. I

2 guess that's the conclusion. And you say yes?

3 MR. PANICKER: Yes. That is one of my

4 slides in the closed session.

5 CHAIR MARCH-LEUBA: I guess it's a good

6 conclusion for the transcript.

7 MR. PANICKER: Okay.

8 CHAIR MARCH-LEUBA: Any questions from the

9 members. Yes?

10 MEMBER KIRCHNER: Just to elaborate on --

11 this is Walt Kirchner. Good afternoon, Matthew.

12 MR. PANICKER: Good afternoon.

13 MEMBER KIRCHNER: From the staff's

14 perspective, the physics methods that they already

15 have are already demonstrated to predict accurately

16 the benchmarks that are used for BWR simulations. So

17 the physics models don't change. The cross sections,

18 okay, you're using ENDF/B-VII.0, right?

19 What were the big issues or areas that the

20 staff focused on because on the surface, these models

21 should -- seven or eight percent is not a big stretch

22 over five percent. So what were you looking at when

23 you did your review? What were your focus areas to

24 come to a conclusion that you would issue an SE

25 approving these methodologies? I'm trying to draw you

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1 out for the public record. What's the big deal here?

2 MR. PANICKER: What I was saying was how

3 did the quantification of all the uncertainties when

4 you analyzed the BWR and then since they're asking

5 about (unintelligible), they are looking for

6 (unintelligible) test cases where some of the test

7 cases are concentrated on higher end of the spectrum

8 and whether there is a comparison between what makes

9 it nicer with the NCNV because the two codes are

10 slightly different configuration. One of them is

11 analytical and one is statistical. So these are some

12 of the main. And also the (unintelligible) updates

13 which we will describe in the closed session.

14 MEMBER KIRCHNER: And then with regard to

15 an 11 by 11 lattice configuration, what were you

16 looking for there to draw your conclusion that these

17 methods are applicable?

18 MR. PANICKER: What we are looking for was

19 if the -- can the core be applicable to an 11 by 11

20 configuration. And also whether when they're going to

21 an 11 by 11 configuration, the uncertainty is provided

22 in the application methodology TR. They are all

23 method, they should describe that they should be

24 within those ranges of applicability. These are the

25 two main things we look for.

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1 CHAIR MARCH-LEUBA: Thank you, Walt. I

2 wanted to place also in the open session, I like very

3 much the approach used on the SER, on the limitations

4 and conditions section. I'm used to seeing SERs that

5 have 25 limitations. Here, you took the approach of

6 dividing that into range of applicability and real

7 limitations. So what sort of limitations and

8 conditions on SERs are not real limitations? They're

9 redefining what's already in topical report. This is

10 only good up to 11 by 11 with this type of cladding

11 within this pressure range. So I want to give

12 positive reinforcement to the staff that I like two

13 sections on the limitation and condition. One is not

14 even a limitation which is the range of applicability.

15 Another one is real limitations where there was a

16 deficiency on the benchmarking above certain range. So

17 I think you guys did a good job, staff, on that.

18 Any more comments, questions from members?

19 So at this point, we're going to open the microphone

20 to members of the public. If somebody wants to make

21 a comment, please open your microphone and say it.

22 We'll give you five seconds to comment.

23 Seeing none, we are going to close this

24 session, but before we go off the transcript, I wanted

25 to ask the members, inform the members, that I have

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1 reviewed the SER and the topical reports and I haven't

2 found any serious deficiency that would merit a letter

3 from us to the staff pointing out something.

4 Basically, our letter would say the standard, both GE

5 and staff did a great job publishing the SER. Because

6 of that, I am proposing that we use our methodology

7 that we will write a short paragraph describing the

8 methodology and describing the recommendation of the

9 subcommittee chair and we will review it and approve

10 it, hopefully, during the P&P session of the full

11 committee which is the only one that has authority to

12 make the decision.

13 So if during the closed session we are

14 going be looking at the actual details, you find

15 something that merits a comment, please keep in mind

16 that we can always backtrack.

17 With that, we are in recess and this

18 meeting link is going to disappear. We will not come

19 back to this room. So we are in recess.

20 (Whereupon, the above-entitled matter went

21 off the record at 1:34 p.m.)

22

23

24

25

NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com ENCLOSURE 1

M230070

ACRS Subcommittee Open Session Presentation Slides for Revision 0 of LANCR02/PANAC11 and Revision 4 of LANCR02 Licensing Topical Reports

Non-Proprietary Information

U. S. NUCLEAR REGULATORY COMMISSION STAFFS EVALUATION OF GLOBAL NUCLEAR FUELS - AMERICAS TOPICAL REPORTS NEDC-33935P, REVISION 0, LANCR02/PANAC11 APPLICATION METHODOLOGY, NEDC-33377P, REVISION 4, LANCR02 LATTICE PHYSICS MODEL QUALIFICATION REPORT, AND NEDC-33376P, REVISION 4, LANCR02 LATTICE PHYSICS MODEL DESCRIPTION

Mathew Panicker, Nuclear Methods and Fuel Analysis Division of Safety Systems

Advisory Committee on Reactor Safeguards Subcommittee Meeting Open Session June 6, 2023 TOPICS COVERED

• Introduction and Background

• Regulatory Evaluation, Review Guidance

• NEDC-33935P, Revision 0, Topical Report (TR) Application Methodology

• NRC Staffs Summary and Conclusions

2 INTRODUCTION AND BACKGROUND

• Global Nuclear Fuels - Americas (GNF-A) is updating its Nuclear Methods to enable fuel enrichments above the current licensing limits.

• Three TRs submitted for review:

- NEDC-33935P, Revision 0, LANCR02/PANAC11 Application Methodology

- NEDC-33376P, Revision 4, LANCR02 Lattice Physics Model

- NEDC-33377P, Revision 4, LANCR02 Lattice Physics Model Qualification Report

3 REGULATORY EVALUATION REVIEW GUIDANCE

• General Design Criterion (GDC) 10 of Appendix A to Part 50, GDC for Nuclear Power Plants

• Section 50.34 of the Title 10 to the Code of Federal Regulations (10 CFR) requires licensees to perform safety analyses of their facilities

• Section 4.3, Nuclear Design, of the NUREG -0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants (SRP)

4 NEDC-33935P, REVISION 0, APPLICATION METHODOLOGY

• Applied to various fuel designs approved for evaluation with LANCR02.

• LANCR02 is a 2-Dimensional lattice physics code that is used to process nuclear data for use in the downstream analysis methods.

• PANAC11 is a static 3-Dimensional coupled nuclear-thermal-hydraulic computer program representing the boiling water reactor (BWR) core exclusive of the external flow loop.

5

SUMMARY

OF TR DEVELOPMENT

• Cold criticals and test cases for benchmarking LANCR02 validation with Monte-Carlo N -Particle (MCNP) code include higher enrichment.

• Updated MCNP5 to MCNP6.2 for qualification.

• LANCR02/PANAC11 Application TR defines methodologies.

• LANCR02/PANAC11 provides uncertainty quantification.

• Assessment of LANCR02/PANAC11 performance through operational qualifications.

• TR establishes guidelines for future updates for model and uncertainty ranges.

6 THE NRC STAFFS

SUMMARY

AND CONCLUSIONS

The NRC staff reviewed the LANCR02/PANAC11 methodology for efficacy demonstration and uncertainty quantification.

The NRC staff reviewed the model description TR and the qualification TR and concludes that adequate models were included in the code to predict the relevant physical processes important for lattice physics analyses.

The results of these qualification analyses justified the applicability of the ENDF/B-VII.0 cross sections to analyze BWRs.

The NRC staff reviewed the LANCR02 Model, LANCR02 Model qualification, and LANCR02/PANAC11 Application Methodology TRs against the acceptance criteria specified in SRP Section 4.3, Nuclear Design.

7 Attendance List Name Timestamp Michael Snodderly 6/6/2023, 12:31:52 PM Thomas Dashiell 6/6/2023, 12:31:52 PM Gerond George 6/6/2023, 12:34:16 PM Kate Lenning 6/6/2023, 12:31:52 PM John Hannan (GNF-A) 6/6/2023, 12:34:16 PM Halac, Kent E (GE Vernova) 6/6/2023, 12:34:16 PM Larry Burkhart 6/6/2023, 12:34:43 PM Mathew Panicker 6/6/2023, 12:36:51 PM Ron Ballinger 6/6/2023, 12:42:57 PM Gregory Halnon 6/6/2023, 12:43:49 PM Court Reporter1 6/6/2023, 12:46:58 PM Tammy Skov 6/6/2023, 12:49:10 PM Vesna B Dimitrijevic (Guest) 6/6/2023, 12:49:30 PM Vicki Bier 6/6/2023, 12:49:46 PM Robert W illiams 6/6/2023, 12:59:15 PM Roberts, Thomas E 6/6/2023, 12:59:40 PM Zena Abdullahi 6/6/2023, 1:01:29 PM Richard Fu 6/6/2023, 1:02:27 PM Benjamin Parks (He/Him/His) 6/6/2023, 1:03:12 PM Gregory Suber 6/6/2023, 1:07:17 PM Sandra W alker 6/6/2023, 1:09:05 PM Kevin Heller 6/6/2023, 1:11:15 PM Sign Language Interpreter 6/6/2023, 1:12:03 PM Jennifer - ASL interpreter (Guest) 6/6/2023, 1:12:04 PM Scott Krepel 6/6/2023, 1:13:24 PM