ML20029E960
| ML20029E960 | |
| Person / Time | |
|---|---|
| Issue date: | 12/05/2019 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| Burkhart, L ACRS | |
| References | |
| NRC-0726 | |
| Download: ML20029E960 (31) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Open Session Docket Number:
(n/a)
Location:
Rockville, Maryland Date:
Thursday, December 5, 2019 Work Order No.:
NRC-0726 Pages 1-16 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 669TH MEETING 4
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
(ACRS) 6
+ + + + +
7 THURSDAY 8
DECEMBER 5, 2019 9
+ + + + +
10 ROCKVILLE, MARYLAND 11
+ + + + +
12 The Advisory Committee met at the Nuclear 13 Regulatory Commission, Two White Flint North, Room 14 T2D30, 11545 Rockville Pike, at 10:45 a.m., Peter 15 Riccardella, Chairman, presiding.
16 17 COMMITTEE MEMBERS:
18 PETER RICCARDELLA, Chairman 19 MATTHEW W. SUNSERI, Vice Chairman 20 JOY L. REMPE, Member-at-Large 21 RONALD G. BALLINGER, Member 22 DENNIS BLEY, Member 23 CHARLES H. BROWN, JR. Member 24 VESNA B. DIMITRIJEVIC, Member 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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2 WALTER L. KIRCHNER, Member 1
JOSE MARCH-LEUBA, Member 2
DAVID A. PETTI, Member 3
4 DESIGNATED FEDERAL OFFICIAL:
5 WEIDONG WANG 6
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.
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3 P R O C E E D I N G S 1
10:47 a.m.
2 CHAIRMAN RICCARDELLA: Okay, so the 3
meeting will come to order. We are going to discuss 4
the GE/GNF control rod drop accident methodology, and 5
the initial part of the meeting is open.
6 MEMBER MARCH-LEUBA: Yes. We will start 7
off with a few minutes of open, then we will close 8
because most of the information is proprietary. So 9
now is --
10 CHAIRMAN RICCARDELLA: Okay. I'll turn 11 the meeting over to Jose March-Leuba, who is chairman 12 of the appropriate subcommittee.
13 MEMBER MARCH-LEUBA: It's called thermal 14 hydraulics.
15 CHAIRMAN RICCARDELLA: Thermal hydraulics.
16 MEMBER MARCH-LEUBA: Okay. So we're going 17 to have some introductory remarks by NFC.
18 MR. OTTO: Okay. Good morning, ladies and 19 gentlemen of the Committee. We're just grateful for 20 the opportunity to present the staff's review of the 21 Global Nuclear Fuel Topical Report. Sitting beside me 22 here is Scott Krepel; he'll be providing the staff's 23 review. We look forward to finishing up today in the 24 full committee.
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4 We can have the subcommittee on Tuesday, 1
and we look forward to receiving your letter at the 2
end of your review. So thank you, and we also 3
appreciate working with GE/GNF during the review in 4
closing out all the technical issues associated with 5
this review. So thank you.
6 MEMBER MARCH-LEUBA: So in the interest of 7
time and the GNF/GE, I made the same joke on the 8
subcommittee. Please tell us who you are, and who you 9
work for. Go ahead.
10 MR. HALAC: Hello, my name is Ken Halac.
11 I'm the licensee for fuel licensing for Global Nuclear 12 Fuels, GE Hitachi, and I'm here with Scott Pfeffer, 13 who is our technical lead in the area of control rod 14 drop, among other things at PDH.
15 MR. PFEFFER: Okay, and I'm Scott Pfeffer.
16 As Ken said, I'm the technical leader for the 17 radiological side of the stability and radiological 18 team at GE/GNF. Prior to that I was senior engineer 19 on the stability side of our team as well for a number 20 of years.
21 So without further ado, we'll get into it.
22 So we'll start with an overview of the licensing 23 topical report; just really briefly talk about the 24 drivers, and then the approach we took. And then 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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5 we'll go over very briefly the remaining milestones we 1
got and, obviously, the meetings today and Tuesday, 2
the final licensee and the issuance of the approved 3
LTR. Next slide.
4 Also, the drivers for our development of 5
the LTR here, we're to align with the latest 6
reactivity-initiated accident fuel damage guidelines 7
and more thoroughly evaluate possible CRDA scenarios.
8 So the staff has recently released new guidance, and 9
we wanted to bring you all up to date on that.
10 Improve plan operations: so, allow for 11 more flexibility during startup, which is a critical 12 time for plant operation, and then prevent inadvertent 13 subcriticality events which have been met with LaSalle 14 15 MEMBER MARCH-LEUBA: I know we discussed 16 the possibilities. Can you tell us what the 17 subcriticality event is?
18 MR. PFEFFER: Right, yes. So for this 19 event during startup, because of the current 20 requirements in banking at BWRs, the top bank position 21 is at four, dash four, and that doesn't have a lot of 22 worth with a lot of new fuel designs. So during the 23 startup the plant is trying to pull those blades; 24 they've got to pull all the blades to four before they 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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6 can pull any blades further in Groups 3 and 4. When 1
they do that, there's not a lot of worth there.
2 They're just continuing to heat up at that point, and 3
they can actually drop back subcritical if they reach 4
criticality --
5 MEMBER MARCH-LEUBA: So this is --
6 MR. PFEFFER: -- prior to that.
7 MEMBER MARCH-LEUBA: -- going to put in a 8
control role, generally so many (unintelligible) shut 9
you down. Is that correct?
10 MR. PFEFFER: Correct, yes. So they can't 11 get enough reactivity from those --
12 MEMBER MARCH-LEUBA: And it is probably 13 periodic, you'd have pulses, right?
14 MR. PFEFFER: Just very little, because 15 you're just not adding enough reactivity from those 16 pulls to four. So the idea of the new LTR is that 17 we'll be able to provide banks which are more 18 impactful and actually more applicable to the new fuel 19 designs as well, to allow those plants to move 20 appropriately through their startups as well as 21 protect against control rod dropbacks (phonetic).
22 And the last item, there's a dose 23 improvement I just want to demonstrate the goal and 24 the requirement of the LTR to demonstrate zero fuel 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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7 rod failures, and so we'll demonstrate that for CRDA 1
and potentially allow some dose consequence 2
improvements in plants as well.
3 Again, the approach that we took was to 4
utilize previously approved methods, so PANAC or 5
PANACEA is our core simulator. PRIME is thermal 6
mechanical methodology, and TRACG is our BWR system 7
code.
8 When implementing NRC guidance related to 9
specifically hydrogen-efficient gas release models, 10 and then the pellet cladding mechanical interaction 11 and high temperature cladding failure enthalpy 12 thresholds. The PCMI version was originally in 13 Appendix B of Section 4.2. Both of those are now in 14 Draft Guide 1327, which is the draft guidance on 15 reactivity-initiated accidents.
16 And so all these base guidances are listed 17 below. The memoranda is initially on the hydrogen 18 uptake and reactivity initiated accidents 4.2 Appendix 19 B, and then most recently Draft Guide 1327, which has 20 been in development for the past number of years.
21 So documentation status: We had a 22 subcommittee meeting on Tuesday. We were actually 23 here for the full committee today. We expect then, 24 pending this review, final IC in January 2020, and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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8 then we'll issue the approved version of the LTR at 1
that point in February 2020.
2 And along with that, we'll issue an update 3
to GESTAR-II in 2020, and so the CRDA LTR was 4
submitted with the modifications to GESTAR-II included 5
as part of that package, and so with the approval of 6
the LTR, those modifications to GESTAR will also be 7
approved.
8 Quick background on GESTAR: It's the 9
General Electric Standard Application for Reactive 10 fuel, and it's their process and methodology for 11 plants they have referenced in their tech specs, and 12 as long as they follow the methodologies and 13 requirements that are part of GESTAR, they can 14 implement, for example, the next fuel product line 15 according to those requirements and guidelines in 16 GESTAR-II without additional review and approval by 17 the staff.
18 MEMBER MARCH-LEUBA: Does the GESTAR cover 19 mixed cores? You could take over a plant from 20 Framatome?
21 MR. PFEFFER: So I would say a number of 22 the methodologies specifically have requirements on 23 mixed cores that are part of GESTAR-II.
24 And that's all I have for the open 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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9 session. Are there any other questions?
1 MEMBER MARCH-LEUBA: We'll now have an 2
open session from the staff, and we'll go into closed 3
session later. Remember, we are still in open 4
session.
5 MR. KREPEL: Okay. So we only have a 6
short time, so I'll get started here. My name is 7
Scott Krepel. I will keep this brief. My background 8
is that I graduated from Purdue almost 20 years ago, 9
and then I spent about 10 years working in the 10 industry at TVA.
11 I worked at Elite Analyst for fuel 12 engineering, and then I came to NRC where I've been 13 working ever since for the last 19 years as a safety 14 analyst. I've worked with the research office and 15 with NRR. Now I'm here to discuss GNF and the CRDA 16 application methodology. Next slide, please.
17 So just a short background for everybody:
18 The GE methodology is based on old guidance from 19 about, I think, the '80s.
20 Hold on one second for the interpreter.
21 It was two 80-calorie per gram, and that 22 was limiting from the old guidance. But more recently 23 the research has shown us that NSRR and other 24 facilities who have done simulations, they did rod 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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10 ejection simulations, and that demonstrated the limits 1
were not very conservative.
2 And so with the more recent guidance in 3
place, we have the SRP 4.2, Appendix B, and so that 4
was able to give us a more current guidance for DG 5
1327, which has just been closed for public comment.
6 That will be coming to you soon for review. So the 7
new method that was proposed by GNR does fit the new 8
guidance, DG 1327, much better. Next slide, please.
9 So their method uses their current 10 approved code which you can see listed behind me. As 11 they had different aspects of their analysis, and all 12 of those codes have already been approved and verified 13 by NRC and all significant phenomena.
14 There's been some additional verification 15 that has been done and looked at for the impact of 16 cold conditions for CRDA activities. Okay, next 17 slide, please.
18 So the GNF did not conduct a formal PIRT, 19 which you might be familiar with, but that's basically 20 where they figure out which phenomena are involved in 21 the accident or the incident, and then they assign a 22 ranking of high, medium, or low importance. And so 23 it's this nice, pretty table that we're able to show 24 you. But GNF did not conduct that PIRT.
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11 But what they did do is, they identified 1
the phenomena, and they created a report that was a 2
comparison, and so it's another PIRT that's available, 3
and so the NRC as able to review that.
4 And that phenomena was identified by GNF, 5
and it was very consistent with other information that 6
we receive, and it did address the uncertainties that 7
we were looking for. So it was a different approach, 8
but they were able to look using bounding values for 9
parameters as well as demonstrating minimal 10 sensitivity and then creating methodology for 11 conservatism.
12 And there were a few uncertainties that 13 were covered with conservatism, and I will be covering 14 those later in the closed session. Next slide, 15 please.
16 So in summary, I won't repeat everything 17 to you, but everything has been listed in the safety 18 evaluation. There are two important requirements:
19 first, they needed to analyze the CRD events; they 20 also had to look at the radiological release.
21 And so there are some additional 22 requirements as well, such as cooling ability, but GNF 23 and their methodology is actually based and 24 demonstrated that there are no fuel incidents.
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12 So we can assume from moving forward, that 1
they meet all the requirements, because there are no 2
radiological release and no loss of cooling.
3 The fuel fair probability evaluation is 4
most useful because the criteria is very similar to 5
the NRC guidance for SRP as well as DG 1327. So with 6
either guidance, they are in compliance, and it is 7
applicable for the licensee to do their analysis.
8 Next slide.
9 So as mentioned briefly, GESTAR-II is a 10 little bit unique. It's unique to GNF and their 11 approach because their licensee is able to implement 12 this methodology without getting further approval by 13 the NRC. They also provide information as needed to 14 support their changing of that fuel, and they will 15 provide clarification as needed about how that 16 methodology or how the information will be updated in 17 the future. That will be discussed a little bit more 18 in depth in the closed session. And that closes my 19 open session of this presentation.
20 MEMBER MARCH-LEUBA: Thank you very much.
21 Can we get --
22 MR. KREPEL: Just a second.
23 MEMBER MARCH-LEUBA: Okay. Can we have 24 any open questions, please?
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13 MEMBER REMPE: Yes. Just to make sure, 1
because we're on the record, it's full committee, and 2
it's hardly worth mentioning, but it is worth 3
mentioning. You did agree in our subcommittee that 4
you would correct a statement regarding Draft Guide 5
1327 in the SE before it's issued, correct? Thank 6
you.
7 MR. KREPEL: Yes, that is correct. That 8
is one comment that we are planning to make sure that 9
we correct on the safety evaluation, absolutely.
10 MEMBER REMPE: Okay, thank you.
11 MR. OTTO: And I know we address it in the 12 final safety evaluation, which we're going to complete 13 after this meeting.
14 MEMBER KIRCHNER: Jose, I have two 15 comments. The first, thank you. We will schedule a 16 meeting on DG 1327 at some period. Now, as Scott 17 pointed out, they've closed the public second round of 18 public comments. But my real comment here is, I'm a 19 little puzzled by the erratic blanket statement that 20 GNF satisfies the requirement ensuring that no fuel 21 failures occur as a result of a CRDA. Isn't that 22 dependent on the actual plant application, not the 23 methodology?
24 MEMBER MARCH-LEUBA: Did you want to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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14 answer it?
1 MEMBER KIRCHNER: We'd prefer.
2 MR. KREPEL: I can answer, yes. Their 3
methodology is specifically intended to allow the 4
licensee to analyze specific plants and then confirm 5
that there are no fuel failures happening at that 6
plant.
7 MEMBER KIRCHNER: I understand that, but 8
which plant? I just don't know -- am I missing 9
something? Is this tied to a specific plant?
10 MEMBER MARCH-LEUBA: Let me -- no, it's 11 not. The methodology is going to determine the bank 12 withdrawal procedures that will be allowable. So if 13 you drop a rod you will not fail any fuel. So if you 14 drop a rod and fail fuel, the bank position is not 15 allowed, and you have to iterate and get a new one.
16 So at the end of the day, for every plant where this 17 is implemented, they will have zero fuel failures by 18 choosing the proper bank positions.
19 MR. KREPEL: Correct.
20 MEMBER KIRCHNER: Correct, I agree. It's 21 just that the methodology doesn't ensure that. It has 22 to be applied to a specific plant and fuel loading, 23 and then you do the analysis. The methodology is 24 being qualified and accepted as a means to make that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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15 determination.
1 MEMBER MARCH-LEUBA: The methodology 2
requires an interruptive procedure and the use of this 3
further (phonetic) criteria.
4 MEMBER KIRCHNER: Okay.
5 MEMBER MARCH-LEUBA: So the methodology, 6
as we said before, has nothing to do with codes, 7
nothing to do with hydraulics. It's only how you 8
iterate to get it done.
9 MEMBER KIRCHNER: Okay. All right. I 10 missed that subtlety.
11 MEMBER MARCH-LEUBA: How you iterate, by 12 the way, is proprietary, so when we have the letter, 13 we will have to recap.
14 Okay. Can you hit the gavel for a moment?
15 I want us to go into a short recess while we set up 16 the closed session, okay? Are there any public 17 comments from the room?
18 MR. BROWN: Thomas, we need to open the 19 public line.
20 MEMBER MARCH-LEUBA: We don't need one 21 together.
22 Are there any members of the public on the 23 phone line? If you would like to make a comment, 24 please identify yourself and make a comment.
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16 MR. HECK: This is Charles Heck of GNF.
1 I'm just commenting so that you know whether or not 2
you can hear somebody.
3 MEMBER MARCH-LEUBA: Thank you. We 4
confirm that the phone line is open, and nobody else 5
wants to make a comment, so at this time we will close 6
the open session.
7 MR. BROWN: Okay. We're going to drop the 8
public line now. GE, we're going to keep the GE line.
9 If you happen to get dropped, please call back into 10 that line, and we will call back in as well.
11 MEMBER MARCH-LEUBA: And GE, can you look 12 around the room and make sure everybody here belongs?
13 I see on this side are all staff members anyway. On 14 that side it's all you.
15 (Whereupon, the above-entitled matter 16 went off the record at 11:06 a.m.)
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Control Rod Drop Accident (CRDA) Application Methodology NEDE-33885P Review December 5th, 2019
©2019 Global Nuclear Fuel - Americas, LLC. - Non-Proprietary Information ACRS Meeting / December 5, 2019, Rockville, MD
©2019 Global Nuclear Fuel - Americas, LLC. - Non-Proprietary Information ACRS Meeting / December 5, 2019, Rockville, MD Licensing Review
- Licensing Topical Report (LTR) Development Overview
- Drivers
- Approach
- Remaining Milestones
- ACRS Meetings
- Final Safety Evaluation (SE)
- Issuance of Approved LTR and GESTAR-II Revisions Contents for Open Portion 2
©2019 Global Nuclear Fuel - Americas, LLC. - Non-Proprietary Information ACRS Meeting / December 5, 2019, Rockville, MD LTR Development Drivers
- Align with latest reactivity-initiated accident fuel damage guidelines
- More thoroughly evaluate possible CRDA scenarios
- Improve plant operations
- Allow for more flexibility during reactor startup
- Prevent inadvertent subcriticality events
- Dose Improvements
- Demonstrate zero fuel rod failures result from a CRDA 3
©2019 Global Nuclear Fuel - Americas, LLC. - Non-Proprietary Information ACRS Meeting / December 5, 2019, Rockville, MD LTR Development (continued)
Approach
- Utilize previously approved methods
- PANAC, PRIME, and TRACG
- Implement NRC guidance
- Hydrogen and Fission Gas Release (FGR) models
- Pellet Cladding Mechanical Interaction (PCMI) and High Temperature Cladding Failure (HTCF) thresholds
- Sources for NRC guidance
- NRC Memoranda ML14188C423 (Reactivity-Initiated Accident Acceptance Criteria) and ML15133A306 (Hydrogen Uptake)
- NUREG-0800, Sections 4.2, including Appendix B, and 15.4.9
- DG-1327 (Control Rod Ejection and CRDA) 4
©2019 Global Nuclear Fuel - Americas, LLC. - Non Proprietary Information ACRS Meeting / December 5, 2019, Rockville, MD Current Status Documentation
- ACRS Subcommittee - December 3rd, 2019
- ACRS Full Committee - December 5th, 2019
- Final SE anticipated January 2020
- Update GESTAR-II expected February 2020 5
Scott Krepel Office of Nuclear Reactor Regulation, US NRC 1
=
Background===
NRC guidance for RIAs has evolved significantly in recent years SRP 4.2 Appendix B DG-1327 Current GNF/GEH methods are based on BPWS NEDE-33885P provides an approach better tailored to current guidance 2
=
Background===
NEDE-33885P only covers an analysis procedure; all codes have previously been reviewed and approved by the NRC TGBLA (lattice physics)
PANACEA (3D core physics)
TRACG (thermal hydraulics)
PRIME (fuel rod performance)
Additional validation performed to confirm applicability of codes to limiting CRDA events 3
CRDA Phenomenology 4
GNF did not perform a formal PIRT, however, they did identify all key phenomena in a manner consistent with other references For each phenomenon, the uncertainties were quantified or dispositioned by:
Using bounding values for parameters Demonstrating minimal sensitivity Crediting methodology conservatism
Acceptance Criteria 5
Current regulatory requirements may be summarized as follows:
CRDA event must be analyzed GNF provides guidance to assure bounding results Any radiological releases must comply with regulatory limits GNF satisfies this requirement by ensuring that no fuel failures occur as a result of CRDA Possibility of fuel failures evaluated primarily via enthalpy based acceptance criteria consistent with NRC guidance (SRP 4.2 Appendix B, DG-1327)
GESTAR & Method Applicability GESTAR II updates to describe relevant documentation requirements (e.g., control rod withdrawal requirements)
Clarifications regarding how methodology can be used New NRC approved models and codes may be used in lieu of those described in the LTR, subject to certain limitations 6
Nomenclature 7
BPWS - Banked Position Withdrawal Sequence CRDA - Control Rod Drop Accident DG - Draft Guide GEH - General Electric - Hitachi GNF - Global Nuclear Fuel LTR - Licensing Topical Report NRC - Nuclear Regulatory Commission RIA - Reactivity Initiated Accident SRP - Standard Review Plan