ML20205L579
| ML20205L579 | |
| Person / Time | |
|---|---|
| Issue date: | 07/07/2020 |
| From: | Charles Brown Advisory Committee on Reactor Safeguards |
| To: | |
| Brown, C, ACRS | |
| References | |
| NRC-0964 | |
| Download: ML20205L579 (24) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Metallurgy and Reactor Fuels Subcommittee Open Session Docket Number:
(n/a)
Location:
teleconference Date:
Tuesday, July 7, 2020 Work Order No.:
NRC-0964 Pages 1-13 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1
1 2
3 DISCLAIMER 4
5 6
UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8
9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.
15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
19 20 21 22 23
1 UNITED STATES OF AMERICA 1
NUCLEAR REGULATORY COMMISSION 2
+ + + + +
3 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
(ACRS) 5
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6 SUBCOMMITTEE ON METALLURGY AND REACTOR FUELS 7
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8 OPEN SESSION 9
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10 TUESDAY, JULY 7, 2020 11
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12 The Subcommittee met via Teleconference, 13 at 2:00 p.m. EDT, Ronald G. Ballinger, Chairman, 14 presiding.
15 COMMITTEE MEMBERS:
16 RONALD G. BALLINGER, Chairman 17 CHARLES H. BROWN, JR. Member 18 VESNA B. DIMITRIJEVIC, Member 19 WALTER L. KIRCHNER, Member 20 JOSE MARCH-LEUBA, Member 21 DAVID A. PETTI, Member 22 PETER RICCARDELLA, Member 23 JOY L. REMPE, Member 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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2 DESIGNATED FEDERAL OFFICIAL:
4 5
6 7
8 9
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3 C-O-N-T-E-N-T-S 1
Opening Remarks and Objectives 5
2 Staff Opening Remarks..............
8 3
Topical Report: Deformable Spacer grid Elements, 4
ANP-10337, Revision 0, Supplement 1 NP, 5
Revision 0...................
9 6
Public comment
................. 13 7
8 9
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4 P R O C E E D I N G S 1
2:00 p.m.
2 CHAIRMAN BALLINGER: Okay. This meeting 3
will now come to order. This is a meeting of the 4
Advisory Committee on Reactor Safeguards, Materials 5
and Reactor Fuels Subcommittee. I'm Ron Ballinger, 6
Chairman of the Metallurgy and Reactor Fuels 7
Subcommittee.
8 Members in attendance are, I believe, 9
Charles Brown, Walt Kirchner, Jose March-Leuba --
10 let's see -- Dave Petti, Joy Rempe, Pete Riccardella, 11 Vesna Dimitrijevic.
12 If I have missed anybody, please say 13 something. I think I got everybody.
14 Christopher Brown and Derek Widmayer are 15 the designated federal officials for this meeting.
16 Chris or Derek, I guess we need to be sure 17 that the recorder is on. Are we sure?
18 PARTICIPANT: Shane (phonetic) has verified 19 that.
20 CHAIRMAN BALLINGER: Good. Thank you.
21 The purpose of today's meeting is for the 22 Subcommittee to receive a briefing on staff safety 23 evaluation for the topical report Deformable Spacer 24 Grid Elements. Today we have members of the NRC staff 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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5 and industry to brief the Subcommittee.
1 The ACRS was established by statute and is 2
governed by the Federal Advisory Committee Act, FACA.
3 The NRC implements FACA in accordance with its 4
regulations found in Title 10 of the Code of Federal 5
Regulations, Part 7.
6 The Committee can only speak through its 7
published letter reports. We hold meetings to gather 8
information and perform preparatory work that will 9
support our deliberations at a full Committee meeting.
10 The rules for participation in all ACRS meetings were 11 announced in the Federal Register on June the 13th, 12 2019.
13 The ACRS section of the US NRC public 14 website provides our charter, bylaws, agendas, letter 15 reports, and full transcripts of all full and 16 subcommittee
- meetings, including slides and 17 presentations there. The meeting agenda for this 18 meeting was posted there.
19 Portions of this meeting will be closed to 20 protect proprietary information pursuant to 5 U.S.C.
21 552 (b)(c)(4). For the open portion of this meeting, 22 we have also set aside five minutes for comments from 23 members of the public attending or listening to this 24 meeting. We have no requests so far for making a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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6 statement to the Subcommittee has been received by the 1
public.
2 A transcript of the meeting is being kept 3
and will be made available on our website for the open 4
portion of the meeting. Therefore, we request that 5
participants in this meeting should first identify 6
themselves and speak with sufficient clarity and 7
volume so that they can be readily heard. Please 8
pause from time to time to allow members to --
9 (Simultaneous speaking.)
10 PARTICIPANT: We're wonderful. How are 11 you?
12 PARTICIPANT: Somebody has got a mic open 13 somewhere.
14 PARTICIPANT: Remember, please mute your 15 mic.
16 CHAIRMAN BALLINGER: Well, we are all 17 wonderful, I guess.
18 Please indicate the slide number that 19 you're on. We have a bridge line established for the 20 public to listen to the meeting. To minimize 21 disturbance, the public line will be kept in a listen-22 only mode. The public line will be terminated during 23 the closed portion.
24 To avoid disturbance, we request that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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7 attendees make sure they are muted. And, again, I've 1
got to check.
2 Thomas, is the public line all set?
3 MR. DASHIELL: Public line is all set.
4 CHAIRMAN BALLINGER: Very good. Thank 5
you.
6 Okay. Note that we have a scheduled 7
meeting, on full Committee, on September 10th.
8 We'll now proceed with the meeting, and 9
I'm going to ask Brian Painter, Framatome, to share 10 his screen with us. He already has done that. Ms. MJ 11 Ross-Lee, Deputy Division Director, Division of Safety 12 Systems NRR, and after, any introductory remarks to 13 make before we begin with today's presentations.
14 And I see she is here, I think.
15 MS. ROSS-LEE: Yes. Hi. Thank you.
16 Good afternoon. As introduced, my name is 17 MJ Ross-Lee. I am the Deputy Director for Division of 18 Safety Systems in NRR. Today we will be discussing a 19 supplement to the topical report, which describes the 20 Framatome analysis methodology for capturing the 21 dynamic behavior of fuel assemblies during oscillatory 22 loads typical of seismic and/or LOCA events.
23 This methodology is used to demonstrate 24 compliance with several regulatory requirements which 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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8 ensure that, among other things, the fuel geometry 1
ensures adequate cooling and the guide tubes are not 2
so severely deformed that control rod insertion is 3
impeded.
4 The supplement adds a new model element 5
that can be utilized within the previously approved 6
analysis framework to represent the unique behavior of 7
certain spacer grid designs such as the GAIA spacer 8
grid. The engagement on this review between NRC, 9
PNNL, and Framatome staff was very efficient, 10 effective, with the use of a regulatory audit which 11 was used to identify and address significant issues 12 via a single round of requests for additional 13 information despite the novel nature of the proposed 14 analysis model element.
15 And with that I will turn it over to 16 Framatome.
17 CHAIRMAN BALLINGER: Brian, are you up?
18 MR. PAINTER: Yes. I'm here.
19 Hello. My name is Brian Painter. I'm an 20 engineer in the Fuel Mechanical Analysis Group at 21 Framatome. And I'll start my presentation.
22 So, moving to slide 2, I'll discuss in 23 this presentation a review of the base methodology, an 24 overview of the GAIA fuel assembly design, and then a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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9 description of the deformable grid methodology.
1 Moving to slide 3, this is a review of the 2
base methodology. So Framatome's generic base 3
methodology, ANP-10337, which is for PWR Seismic and 4
LOCA mechanical evaluations -- it was approved in 5
August 2018. And what it accomplishes for us in the 6
methodology space is it updates the lateral dynamic 7
models, vertical dynamic modeling, and the on-grid 8
component stress analysis. It also addresses NRC 9
information that is 2012-09, which were radiation 10 effects on spacer grid crush strength.
11 CHAIRMAN BALLINGER: Somebody's got their 12 microphone not muted. Please.
13 MR. PAINTER: Okay. Thank you.
14 It also defines the spacer grid allowable 15 impact load and allowable spacer grid permanent 16 deformations.
17 So, in the base methodology, the impact 18 response of the spacer grid is assumed to be linear up 19 to the allowable impact load. With new spacer 20 designs, as mentioned, the GAIA design in particular, 21 they exhibit a linear impact response but a limited 22 one, which is then followed by a nonlinear impact 23 response.
24 So the deformable spacer grid methodology, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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10 its intent is to extend the base methodology to 1
address spacer grids with these nonlinear impact 2
responses.
3 On slide 4, I would like to say that most 4
of the base topical remains applicable to this 5
supplement, to the deformable grid supplement. So the 6
fuel assembly beam model architecture is unchanged.
7 The damping and the hydrodynamic coupling terms that 8
we apply in the row models and vertical models, 9
they're unchanged.
10 How we treat irradiation effects on spacer 11 grade testing is unchanged, and the non-grid component 12 stress evaluations are unchanged. So the deformable 13 grid supplement, all it's doing, in essence, is 14 replacing the linear grid impact element with a 15 nonlinear impact element.
16 Moving to slide 5, so we'll speak about 17 the GAIA fuel assembly and the GAIA spacer grid a lot 18 during the open and close presentation because this 19 was the spacer grid that kind of launched this effort.
20 So it's worth giving an overview of the fuel assembly 21 design.
22 So it's Framatome's latest fuel assembly 23 design for Westinghouse 17 x 17 reactors. As I've 24 already mentioned, the GAIA spacer grid introduces a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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11 nonlinear response in seismic and LOCA excitations 1
from moderate impacts. So, smaller energy impacts, 2
the grid remains linear. But, as we increase the 3
impact energies, we can see that -- and we'll show in 4
the close presentation -- that the nonlinearities 5
become more important.
6 Now, the spacer grid linear response has 7
been analyzed using the generic base methodology, the 8
topical report 10337. It was analyzed as part of the 9
sample problem for ANP-10342, which is the GAIA 10 mechanical design topical report.
11 Moving to slide 6. So a little more 12 detail about the deformable grid methodology. So the 13 supplement, it implements a nonlinear deformable grid 14 model, and that will replace the linear viscoelastic 15 spring that is described in the base methodology.
16 The deformable grid element, or DGE for 17 short, it can simulate the nonlinear impact response, 18 and it can predict the residual spacer deformations 19 that occur during seismic and LOCA events. Including 20 the DGE or the nonlinear element, it doesn't alter the 21 modeling of fuel assembly tentative response.
22 As mentioned earlier, the beam model 23 architecture is unchanged, as are other aspects of the 24 analysis. One thing that does change is we knew from 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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12 an exception to criteria in the base method that's 1
based on a limiting impact load and we're replacing 2
this with a limiting residual deformation.
3 I will take any questions you have.
4 CHAIRMAN BALLINGER: Okay. We have a 15-5 second rule, I guess. If there are no comments on 6
this, I think we need to first check the public line 7
to see if there's any members of the public that would 8
like to make a statement.
9 Thomas, I'm assuming the public line is 10 open.
11 MR. DASHIELL: Public line is open.
12 CHAIRMAN BALLINGER: Yeah. So are there 13 any members of the public that would wish to make a 14 statement regarding this?
15 (Pause.)
16 CHAIRMAN BALLINGER: Okay. Hearing none, 17 I guess we can close the public line. And this would 18 be, also, the end of the public part of this meeting.
19 And so what we need to do, and Chris can correct me if 20 I'm wrong, is we need to -- there's a different 21 invitation, right, Chris?
22 MR. BROWN: Absolutely.
23 CHAIRMAN BALLINGER: So everybody needs to 24 get out of this meeting, and then we rejoin the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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13 meeting using the invitation for the closed session.
1 So --
2 MEMBER REMPE: Ron, before you do that, 3
though, don't you need to ask for public comment?
4 CHAIRMAN BALLINGER: I did.
5 MEMBER REMPE: I'm sorry. Then I guess I 6
missed it. Okay. I apologize.
7 CHAIRMAN BALLINGER: Yeah. Senior moment.
8 (Simultaneous speaking.)
9 CHAIRMAN BALLINGER: Anyway, okay. So I 10 think what we need to do is say goodbye to this 11 meeting, and then we'll see you shortly in the closed 12 session.
13 MR. BROWN: And Derek and I will verify 14 the people that are coming into the closed session.
15 Thank you.
16 (Whereupon, the above-entitled matter went 17 off the record at 2:14 p.m.)
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1 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Brian Painter July 7, 2020 ACRS Subcommittee Meeting Topical Report Supplement to ANP-10337P-A for Deformable Grids
2 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 2
CONTENT
- 1. Review of Base Methodology
- 2. GAIA Fuel Assembly Design
- 3. Description of Deformable Grid Methodology
3 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Review of Base Methodology Framatomes generic base methodology for PWR Seismic / LOCA mechanical evaluations, ANP-10337P-A, was approved in August 2018 ANP-10337P-A:
- Updates the lateral dynamic modeling, vertical dynamic modeling, and component stress analysis
- Addresses NRC Information Notice 2012-09 Irradiation Effects on Fuel Assembly Spacer Grid Crush Strength
- Defines spacer grid allowable impact load and allowable grid permanent deformations In the base methodology, the spacer grid impact response is assumed to be linear up to the allowable impact load New spacer grid designs, such as the GAIA design, exhibit a limited linear impact response followed by a nonlinear response The deformable spacer grid methodology is intended to extend the base methodology to address spacer grids with these nonlinear impact responses.
4 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Review of Base Methodology Most of the base topical remains applicable to the deformable grid supplement
- Fuel assembly beam model architecture is unchanged
- The applied damping and hydrodynamic coupling are unchanged
- The treatment of Irradiation effects on spacer grid testing is unchanged
- Non-spacer grid component stress evaluation is unchanged The deformable grid supplement simply replaces the linear grid impact element with a nonlinear impact element
5 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 GAIA Fuel Assembly The GAIA assembly is Framatomes latest 17x17 design for Westinghouse reactors The innovative GAIA spacer grid introduces a nonlinear response to external excitation
- For moderate impacts, the grid remains linear
- For larger impacts, the nonlinearities become important The grid linear elastic response was analyzed in the ANP-10342P-A sample problem using the generic ANP-10337P-A methodology
6 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Deformable Grid Methodology Supplement 1 to ANP-10337P-A implements a nonlinear, deformable spacer grid model to replace the linear visco-elastic spring prescribed in the base methodology The deformable grid element (DGE) can simulate the nonlinear impact response and predict residual spacer grid deformations due to seismic and LOCA events The inclusion of the DGE does not otherwise alter the modeling of the fuel assembly dynamic response The limiting impact load acceptance criteria from the base methodology are replaced with limiting residual deformations
7 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Acronyms ANCOVA - Analysis of Covariance BOL - Beginning of Life EOL - End of Life LOCA - Loss of Coolant Accident NRC - U.S. Nuclear Regulatory Commission SSE - Safe Shutdown Earthquake UCL - Upper Confidence Limit
8 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 GAIA, M5Framatome, and M5 are trademarks or registered trademarks of Framatome or its affiliates, in the USA or other countries.
Trademarks
9 ACRS Meeting - ANP-10337 Supplement 1P - July 7, 2020 Thank you