ML21064A373
| ML21064A373 | |
| Person / Time | |
|---|---|
| Issue date: | 09/24/2020 |
| From: | Zena Abdullahi Advisory Committee on Reactor Safeguards |
| To: | |
| Abdullahi, Z, ACRS | |
| References | |
| NRC-1108 | |
| Download: ML21064A373 (68) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Materials and Metallurgy Subcommittee Open Session Docket Number:
(n/a)
Location:
teleconference Date:
Thursday, September 24, 2020 Work Order No.:
NRC-1108 Pages 1-43 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1
1 2
3 DISCLAIMER 4
5 6
UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8
9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.
15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
19 20 21 22 23
1 UNITED STATES OF AMERICA 1
NUCLEAR REGULATORY COMMISSION 2
+ + + + +
3 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
(ACRS) 5
+ + + + +
6 METALLURGY AND REACTOR FUELS SUBCOMMITTEE 7
+ + + + +
8 OPEN SESSION 9
+ + + + +
10 THURSDAY, SEPTEMBER 24, 2020 11
+ + + + +
12 The Subcommittee met via Video 13 Teleconference, at 9:30 a.m. EDT, Jose March-Leuba, 14 Chairman, presiding.
15 COMMITTEE MEMBERS:
16 JOSE MARCH-LEUBA, Chair 17 RONALD G. BALLINGER, Member 18 CHARLES H. BROWN, JR., Member 19 VESNA B. DIMITRIJEVIC, Member 20 WALTER L. KIRCHNER, Member 21 DAVE A. PETTI, Member 22 JOY L. REMPE, Member 23 PETE RICCARDELLA, Member 24 MATTHEW W. SUNSERI, Member 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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2 ACRS CONSULTANT:
1 STEPHEN P. SCHULTZ 2
3 DESIGNATED FEDERAL OFFICIAL:
4 ZENA ABDULLAHI 5
6 NRC STAFF PRESENT:
7 JOE DONOGHUE, NRR/DSS 8
MATHEW PANICKER, NRR/DSS/SFNB 9
10 ALSO PRESENT:
11 JERALD HOLM, Framatome 12 NGOLA OTTO, Framatome 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
9:30 a.m.
2 CHAIR MARCH-LEUBA: Okay, it's 9:30, this 3
meeting will now come to order. This is a meeting of 4
the ACRS Accident Analysis Thermal Hydraulics 5
Subcommittee. I am Jose March-Leuba, the SC Chairman.
6 Because of COVID-19 concerns, this meeting 7
is being conducted remotely. I see on the list of 8
attendants we have Member Ron Ballinger, Charles 9
Brown, Vesna Dimitrijevich, Walter Kirchner, David 10 Petti, Joy Rempe, Pete Riccardella, Matt Sunseri.
11 Today's topic is Topical Report ANP-12 10323P, Revision 1, GALILEO Fuel Rod Thermomechanical 13 Methodology for Pressurized Water Reactors. Portions 14 of the meeting will be closed to the public to protect 15 proprietary information. We will have an opportunity 16 for public comments before we start the closed section 17 of the meetings.
18 The ACRS was established by a statute and 19 it's governed by the Federal Advisory Committee Act, 20 FACA. As such, the Committee can only speak through 21 its published letter reports. The ACRS section of the 22 US NRC public website provides our charter, bylaws, 23 agendas, letter reports, and full transcripts for the 24 open portions of all full and subcommittee meetings, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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4 including the slides presented there.
1 The Designated Federal Official today is 2
3 A transcript of the meeting is being kept, 4
therefore, please speak clearly and state your name 5
for the benefit of the court reporter. Please keep 6
the microphone on mute when not in use and don't use 7
video feed to minimize bandwidth problems.
8 We know that we have scheduled a full 9
Committee meeting on this topic in early October to 10 write a letter. And I also wanted to note to the 11 members that we have two topics. The main topic of 12 this committee is the GALILEO fuel thermal properties 13 methodology. But we will also have an information 14 meeting on the best estimate Option III solution, 15 which is a long-term stability solution that we 16 already reviewed in plant-specific basis.
17 Now the staff is in the process of 18 reviewing the Generic Topical Report that will be 19 applicable to all plants. And they have asked us if 20 we want to review it when it's done, which is expected 21 the February time range, or not. And I made a 22 decision that probably because we have already 23 reviewed it in detail, we only needed a short 24 information meeting where we see the differences 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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5 between the generic and the plant-specific.
1 So at the end of this presentation, we 2
will be hearing something about BEO-III, and we will 3
ask the members if we want to have a full committee 4
meeting on a letter, or this information is 5
sufficient.
6 So at this point, let's request the NRC 7
staff, Joe Donoghue, to make the introductory remarks.
8 Joe, you're in charge.
9 MR. DONOGHUE: Thank you, sir, this is Joe 10 Donoghue. I'm a Director of the Division of Safety 11 Systems in NRR.
12 Thank you for taking the time to let us 13 present the Safety Evaluation that our staff's 14 prepared on GALILEO. It's a methodology for a 15 realistic evaluation of the performance of fuel rods 16 in PWRs. And this is an important step in the 17 vendors' suite of analysis methods and information 18 they're going to provide related to ATF designs that 19 they're pursuing.
20 So you're going to hear some details today 21 about the thermal model, how it predicts the fuel 22 swelling, densification, how it -- in other parts of 23 the mechanical models. And then what licensing 24 applications are expected -- that this would be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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6 expected to apply to.
1 So we've done a detailed review. We 2
worked very closely with Framatome. I'm going to say 3
out loud here that we've I think done a good job, the 4
staff, working with Framatome. Framatome's done a 5
good job being supportive of our needs to get to a 6
Safety Evaluation that's before you.
7 So thanks very much, looking forward to a 8
good meeting.
9 CHAIR MARCH-LEUBA: Thanks, Joe. At this 10 point we give the floor to Framatome. I believe we're 11 going to have a tag team of Jerald Holm and Chris 12 Allison. And NRC will be providing the slides.
13 So Framatome, go ahead.
14 MR. HOLM: So good morning, my name is 15 Jerry Holm, and I'm a Licensing Engineer for 16 Framatome. We appreciate the opportunity to present 17 Framatome's advanced fuel performance code for PWRs to 18 the ACRS. The code GALILEO is a key element in our 19 suite of advanced methods, and will be part of future 20 submittals. I expect we may be back talking about 21 GALILEO in support of these future submittals.
22 In particular, we appreciate the ACRS 23 scheduling the full committee meeting on this topic 24 for October 8 of 2020, so that the final SE may be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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7 issued in October.
1 With that, I'll turn it over to Chris.
2 MR. ALLISON: All right, thank you, Jerry.
3 Can everybody hear me okay?
4 MEMBER SUNSERI: Yes.
5 MR. ALLISON: Okay, very good. Otto, do 6
we -- excuse me, Ngola, do we have the slides 7
available to bring up?
8 MR. OTTO: Yes, I'm loading them right 9
now. So you should see them momentarily. Are you 10 able to see the slides now?
11 CHAIR MARCH-LEUBA: I can.
12 MR. ALLISON: Yes, it has come up. Thank 13 you.
14 So as introduced, my name is Chris 15 Allison, I am the GALILEO project leader for the 16 licensing in the United States. I'm in the Fuel 17 Thermal Mechanics Department here at Framatome. If 18 you go to slide 2, please.
19 Just a quick overview of the topics I'm 20 going to discuss this morning in the open session.
21 I'll give you some background to get you grounded in 22 the history of GALILEO and its development. I'll 23 provide a brief overview of the topical report and 24 give some details on the GALILEO fuel performance 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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8 code, and then the statistical evaluation methodology 1
that it's paired with. And then I'll give a view of 2
how GALILEO fits within our future plans for our 3
advanced methods platform. Slide 3, please.
4 So, background. So the development of 5
GALILEO was initiated with the goal to consolidate 6
Framatome's worldwide expertise and experience into a 7
single fuel performance code. And in doing so, we 8
hoped to build upon all the best practices and 9
techniques from our current generation of fuel 10 performance codes.
11 And that includes COPERNIC, which is used 12 in France and the United States for PWR applications.
13 It includes RODEX4, which is used in the United States 14 for BWR applications. And it includes CARO-3E, which 15 comes from Germany.
16 The original development was to support a 17 very broad range of applications, and that included 18 PWR and BWR applications, and included UO2, gadolinia, 19 and MOX fuels. During the process of the review, we 20 submitted a revised topical report, and in that 21 revision, we made a specific removal of the BWR 22 applications and the MOX fuels. And that was 23 consistent with our evolving priorities and strategies 24 for where we wanted to go with our codes and methods.
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9 And so the requested NRC approval that we 1
have today is for PWR applications, it's for UO2 and 2
gadolinia fuel types, with either M5 or Zr-4 cladding.
3 CHAIR MARCH-LEUBA: Chris, this is Jose.
4 I -- can you give us a little background on why you 5
decided to drop BWRs and MOX at this time? Because 6
this approval has been going on for a long time. Was 7
it an issue with being able to develop models inside 8
the code, or the issue was validation against data?
9 The timing, no need for it? Why did you do it?
10 MR. ALLISON: It was mostly an issue of 11 timing and the strategy that we decided to employ for 12 our codes and methods. We had already invested 13 strongly in our BWR methods using RODEX4, and we 14 decided that we did not want to repeat that process, 15 to go again with GALILEO. And so we decided that 16 RODEX4 was the better option there.
17 In terms of MOX fuel, that was more in 18 terms of the, I would say the general dynamics of the 19 MOX program in the United States. And then as that 20 program kind of came to a stopping point or a, maybe 21 an interim hold point, we decided it was better to 22 wait and pursue that at a different time. So it's 23 mostly just a timing issue and how it fit within our 24 strategy.
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10 MEMBER BALLINGER: This is Ron Ballinger.
1 To my knowledge, there are no plants in the U.S. that 2
are -- no PWRs that are using Zr-4 cladding anymore.
3 So including Zr-4, is that as an afterthought?
4 MR. ALLISON: I would kind of --
5 MEMBER BALLINGER: Or is it the fact that 6
COPERNIC already has it in it?
7 MR. ALLISON: I think from my perspective 8
it's almost like a bit of a security blanket issue.
9 It leaves that option open for us if, you know, if we 10 ever had an emergency need where we needed to do an 11 evaluation of an old fuel assembly with Zr-4 cladding, 12 this approval would allow us to do that. But I do 13 agree with your evaluation that Zr-4 cladding is 14 basically an obsolete product in the market today.
15 MEMBER BALLINGER: Thank you.
16 CHAIR MARCH-LEUBA: Okay, thank you, 17 proceed.
18 MR. ALLISON: Okay, slide 4, please. So 19 in terms of the overview of the topical report, it 20 does describe a methodology for the realistic 21 evaluation of the thermal-mechanical performance of 22 the fuel rods for PWR applications. And this is for 23 demonstrating compliance with many of the fuel rod 24 requirements that come from Section 4.2 of NUREG-0800.
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11 The methodology is composed of two major 1
components, the first being the GALILEO fuel 2
performance code, and then the second being the 3
statistical evaluation methodology that employs 4
GALILEO. And the topical report describes the 5
requirements and capabilities of the GALILEO fuel 6
performance code.
7 It describes how the code is calibrated, 8
validated, and the range of parameters over which that 9
process was performed. It describes the uncertainty 10 analyses and how those were selected and how they were 11 developed based on the data. And then it provides a 12 series of demonstration analyses to show how the code 13 performs and how the methodology is applied to 14 different plant types and fuel types. Slide 5, 15 please.
16 So the GALILEO fuel performance code is a 17 best estimate fuel rod performance code that simulates 18 the thermal and mechanical response of the fuel rods 19 in the reactor core as a function of their exposure 20 for the local power and flow conditions. It's based 21 on phenomenological rate-dependent models, and those 22 were used to evaluate things like the temperatures, 23 the strain, and exposure-dependent changes in the fuel 24 and cladding materials and the fission gas releases 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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12 that occur during operation.
1 It includes modeling of things like 2
thermal conductivity degradation with burnup and 3
irradiation damage. It has models for enhanced 4
fission gas release at high burnup conditions and in 5
transient conditions. And it also includes the 6
formation of high burnup structure on the pellet rim 7
and how that impacts the fuel behaviors at high 8
burnup.
9 And maybe one of the more important 10 things, or more advanced things, excuse me, is that it 11 includes many new models in the pellet mechanic 12 modeling and behavior that go a step beyond where our 13 current generation of fuel performance codes are.
14 And then the -- go ahead.
15 CHAIR MARCH-LEUBA: Chris, when you say 16 phenomenological rate-dependent model, what do you 17 mean by that? What rate?
18 MR. ALLISON: So it could be many 19 different things. One example would be a corrosion 20 model where the model is developed to evaluate the 21 corrosion rate over time, and then that performance is 22 integrated to provide, you know, an oxide thickness at 23 a given point in time.
24 It could also be a creep model, where the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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13 creep model is based on the rate of creep, given the 1
conditions at a certain point in time. And then that 2
behavior is integrated over the lifetime of the rod.
3 CHAIR MARCH-LEUBA:
So for a
4 mathematician, you are saying that you are modeling 5
the non-linearities in the system and the histories if 6
any are this history of the burnup.
7 MR. ALLISON: Yes, yes, that is correct.
8 CHAIR MARCH-LEUBA: Okay, thank you.
9 MEMBER BALLINGER: This is Ron Ballinger 10 again. Am I to assume, I think I read it, that this 11
-- you're assuming chromia-doped fuel as well?
12 MR. ALLISON: Chromia-doped fuel is a 13 piece that will be addressed in a future step.
14 MEMBER BALLINGER: Okay, okay. Thank you.
15 MR. ALLISON: And then the last piece of 16 this is that the fuel performance code is calibrated 17 and validated using a very extensive database of 18 measurements to both commercial rods and experimental 19 test rods, both from in Europe and in the United 20 States. And that really forms the backbone of the 21 GALILEO fuel performance code and assessing its 22 ability to predict rod performance.
23 MEMBER KIRCHNER: Chris, this is Walt 24 Kirchner.
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14 MR. ALLISON: Yes.
1 MEMBER KIRCHNER: How generic would you 2
describe the models in this open session? And I'm 3
anticipating future developments in claddings in 4
particular. So you have a fairly generic base set of 5
models that could be adapted for changes in cladding?
6 MR. ALLISON: I think that's a fair 7
assessment. Generally the models are -- we try to 8
base them on physics, so it's based on, you know, 9
principles that are, that should be able to extend 10 into different materials.
11 And then, you know, specific tuning is 12 done to make that model work for a given material.
13 But I do think the basis of the model does allow that 14 we could make some application to a different material 15 in the future, just needing to make some calibration 16 of that model to the specific material.
17 MEMBER BALLINGER: Are you saying that 18 this phenomenology or the generic model can be used 19 for non-zirconium alloy tubing?
20 MR. ALLISON: I don't know that I would 21 say it could be used for non-zirconium alloy tubing.
22 MEMBER BALLINGER: I didn't expect -- I 23 didn't expect so, thanks.
24 MR. ALLISON: Okay, slide 6, please. So 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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15 the next piece of the topical report describes the 1
statistical evaluation methodology.
And the 2
methodology is used to analyze rod performance during 3
normal operating and AOO conditions for a given fuel 4
reload and at a given power plant. It considers 5
uncertainties over the projected range of operation of 6
the rods in the core. And you should take that to 7
mean the power histories for each rod.
8 And it includes the impact of measured and 9
calculated power uncertainties, uncertainties in the 10 manufactured fuel rod characteristics, and 11 uncertainties in the GALILEO models. It employs a 12 random sampling of those three uncertainty components 13 that's similar to a Monte Carlo process, and it uses 14 that with the best estimate GALILEO code, and then 15 applies non-parametric order statistics to evaluate 16 how those uncertainties propagate and influence the 17 design analysis result.
18 And ultimately what we want to do is 19 demonstrate that the fuel meets the design criteria 20 with a quantified probability and confidence level.
21 Slide 7, please.
22 So in closing, I'd like to give you a 23 little perspective on where GALILEO fits in the future 24 of our codes and methods suites and where it fits with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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16 our advanced technologies. And GALILEO really does 1
fill a foundational role in that. You can start here 2
at the first with a PWR rod ejection accident 3
analysis.
4 This is a methodology that we've had 5
approved by the NRC. It is -- it would be based on 6
GALILEO, and that would be our foundation to support 7
the new requirements and the new guidance that come 8
from Regulatory Guide 1.236.
9 The next piece would be our advanced non-10 LOCA transient analysis methodology. And you may see 11 that called the ARITA methodology. That is a topical 12 report that's currently in review by the NRC, and it 13 uses GALILEO for the evaluation of fuel melt and 14 cladding strain during transient events.
15 The next piece would be our advanced LOCA 16 analysis methods. And these would be using GALILEO to 17 provide fuel rod input to the LOCA analysis. And you 18 would expect to see -- you can expect to see that in 19 a future submittal.
20 The next piece would be our advanced fuel 21 management program.
And this is targeting 22 applications such as increasing our burnup limits.
23 We're using higher enrichment in our fuel pellets, and 24 you can expect to see those in future submittals as 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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17 well. And GALILEO is a basis behind those.
1 And then the last piece would be the 2
enhanced accident-tolerant fuel program, which you 3
would also see in future submittals. And here GALILEO 4
would be a supporting role for that, for the different 5
types of technologies that we're exploring in that 6
program.
7 MEMBER REMPE: So Chris, this is Joy 8
Rempe. When you start thinking about what you're 9
going to do when you go for new fuels and enhanced 10 accident-tolerant fuels, and the fact that Halden has 11 shut down, what's the plan for Framatome for getting 12 data for extended burnup for these new fuels?
13 MR. ALLISON: I am maybe not the best 14 person to comment on the plans for the accident-15 tolerant fuel program. I do know that there are plans 16 of how they want to try to address different testing 17 needs in the absence of Halden, and that might rely on 18 more homegrown testing here in the United States, 19 either out at Idaho or maybe at Oak Ridge. But the 20 details of that plan I am not cognizant of.
21 MEMBER REMPE: So it's off-topic a bit, 22 I'll grant you that, but I was reading your reports 23 and the information we were given for this and 24 thinking about the burnup limitations for various 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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18 fuels. And I'd note that you can't really do it at 1
Oak Ridge. And so yeah, maybe you could do something 2
out at ATR, but they don't have the instrumentation 3
capabilities they had at Halden.
4 Sometimes people talk about, well, the 5
Jules Horowitz Reactor. And again, it's not up and 6
running yet. But I think it's going to be hard to 7
when you start talking about different things that are 8
up for certain, up to certain burnups, what you're 9
going to do in the future here. And I'm just curious 10 what -- and you know, I think it's something that 11 people need to think about.
12 MR. ALLISON: I agree completely with you.
13 The loss of Halden is important for the industry as a 14 whole, and specifically in terms of what it means for 15 accident-tolerant fuel. And as you want to proceed 16 into these ranges where we don't have data, it is 17 going to be a substantial challenge.
18 MR. SCHULTZ: Chris, this is Steve 19 Schultz. I have a general question on the additional 20 submittals that you're anticipating. Are you 21 expecting that you're going to have to make changes to 22 GALILEO in these submittals, that there's going to be 23 additional model changes that may be required for 24 these future applications?
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19 MR. ALLISON: I think that's a certainty, 1
if you're speaking about accident-tolerant fuel. I 2
think you would certainly see new modeling come in to 3
handle those different materials and different fuel 4
types that are being addressed there.
5 In terms of the advanced fuel management, 6
I would not expect that to be the case.
7 MR. SCHULTZ: You already have information 8
related to both increased -- well, to increased burnup 9
at least, higher enrichment. I guess it depends where 10 you intend to go with that, given what you presented 11 in the GALILEO application.
12 MR. ALLISON: That's correct.
13 MR. SCHULTZ: So that would be a -- that 14 could be a validation of what has already been 15 presented to the NRC. Again, it depends where you're 16 intending to go with that. Thank you.
17 MR. ALLISON: Yes, yes, I would agree with 18 that statement. In future submittals, that would come 19 up along those lines of increased burnup and higher 20 enrichment, would certainly address how GALILEO and 21 its methodology addresses those items, but it also 22 includes many other items. And so those are much more 23 24 MR. SCHULTZ: How are where you're --
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20 excuse me, yeah, how about what will you expect --
1 where you expect to go with the LOCA analysis methods.
2 Is what you have and what we're reviewing now as you 3
see it satisfactory for what you're anticipating for 4
your future submittal?
5 MR. ALLISON: I would have to defer that 6
question because I am not involved with the LOCA 7
analysis method. So I would have to defer that to 8
someone more involved with that program.
9 MR. SCHULTZ: That's fine, thank you.
10 MEMBER BALLINGER: This is Ron again.
11 MEMBER PETTI: But to be clear, this, 12 GALILEO, what we're really reviewing is the steady 13 state.
14 MEMBER BALLINGER: Yeah, that's what I was 15 about to say. It's not a transient code.
16 MEMBER PETTI: At least the transient 17 capabilities we're not reviewing. We're really 18 focusing on steady state.
19 CHAIR MARCH-LEUBA: Jerry, could you 20 comment on that? Because when you do the non-LOCA 21 transient analysis, which is currently under review, 22 how is it coupled to the calculation?
23 MR. ALLISON: I'm sorry.
24 CHAIR MARCH-LEUBA: Do you understand the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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21 question? If you apply the GALILEO methodology to 1
evaluate the results of a rod ejection or a non-LOCA 2
transient, how do you do it? Do you do it in quasi-3 steady states like this?
4 MR. ALLISON: So for -- I can speak first 5
to the PWR rod ejection. So the main application of 6
GALILEO there would be more in terms of like initial 7
conditions and the initiation of the accident.
8 Providing things like an initial hydrogen content, for 9
example.
10 In the non-LOCA transient analysis, 11 GALILEO does include, I think I would go with your 12 statement of quasi-steady, quasi-steady state or 13 quasi-transient. And so it has the capability to make 14 those transient types of predictions for fuel center 15 line melt evaluations and clad strain evaluations.
16 CHAIR MARCH-LEUBA: So you would use ARITA 17 to calculate the coolant conditions and the fuel power 18 to each rod. And then every time step, you will do a 19 steady state GALILEO calculation to calculate the 20 center line temperature. Is that reasonable to say?
21 MR.
ALLISON:
That's a
reasonable 22 assessment, yes.
23 CHAIR MARCH-LEUBA: Okay.
24 MEMBER BALLINGER: This is Ron again, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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22 it'll probably be a lot of agains. In part -- not to 1
get into proprietary stuff, but does the non-LOCA 2
transient part include accounting for liftoff of the 3
cladding from the fuel?
4 MR. ALLISON: I think I would -- if I can 5
defer that question to the closed session.
6 MEMBER BALLINGER: Okay, fine.
7 MR. ALLISON: I can answer it there.
8 MEMBER BALLINGER: Yep, thanks.
9 MEMBER KIRCHNER: Chris, this is Walt 10 again. I had to ask rather a leading question, and 11 some of your bullets here addressed where I was going 12 with my question.
13 But when you describe this as a platform, 14 or I'm sorry, a methodology, that has rate-dependent 15 phenomena, what you're really talking about, the rates 16 you're talking about are time at temperature, time 17 exposure, burnup, not transient -- do you also mean 18 transient performance as would be used for something 19 like a LOCA analysis where you've got a quick 20 transient and the dynamics that go with that?
21 Or maybe we save this for the closed 22 session. You see what I'm saying?
23 MR. ALLISON: Yes.
24 MEMBER KIRCHNER: Things like pellet clad 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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23 interaction under those LOCA kind of transients is a 1
rate-dependent phenomenon as well. But that's very 2
quick, not the -- I presume the rate-based phenomena 3
that you're generally talking about are time, you 4
know, exposure, burnup over a fuel cycle, not over a 5
short-term transient.
6 MR. ALLISON: I believe that is a correct 7
assessment. And we can -- we could go more detail on 8
that in the closed session if you would like.
9 MEMBER KIRCHNER: The one I was reacting 10 to was fission gas release in particular. Because for 11 the rod ejection accident, that certainly is a rate-12 dependent phenomenon, but a very short -- and during 13 a very short transient.
14 MR. ALLISON: Right. I think in terms of 15 the speed of an event, we would say the rates we're 16 talking about are for normal operations and for 17 typical AOO-type of events, but --
18 MEMBER KIRCHNER: Right, so as one of my 19 colleagues pointed out, more quasi-steady state, so to 20 speak.
21 MR. ALLISON: Yes. And things like rod 22 ejection and LOCA would bring in new sets of 23 phenomena. And you address those types of rate 24 dependencies in those specific methodologies.
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24 CHAIR MARCH-LEUBA: Any more questions for 1
Framatome before we transfer to the staff? Okay, 2
thanks, Chris.
3 MR. ALLISON: Thank you.
4 CHAIR MARCH-LEUBA: We are going to start 5
the presentation by the staff. It's going to be also 6
a team of two, Mathew Panicker and Ken Geelhood.
7 So Mathew, are you going to talk?
8 MR. PANICKER: Yeah, this is an open 9
session. Next up is a team of engineers from NRC and 10 PNNL who were involved in the review of this GALILEO 11 code, ANP-10323, Revision 1. The review was focused 12 on the core, and the assessment of the individual 13 models in the core, for example thermal model, fission 14 gas release model, et cetera, mechanical models.
15 Assessment of the integral core predictions.
16 The methodology consisted of assessing --
17 the review consisted of assessing proposed 18 uncertainties, the statistical methodology Framatome 19 used for various models and assessment, and assessment 20 of fuel damage limits. Next please.
21 The Revision 0 of the methodology topical 22 report was submitted in October 2013, and it is based 23 on realistic evaluation of the thermal-mechanical 24 performance of fuel rods for pressurized water reactor 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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25 fuels, PWR fuels. And original submission was 1
applicable to PWR, BWR, and MOX fuels, and later on 2
NRC suspended -- requested the suspension of MOX and 3
BWR fuels. It has got burnable absorbers, UO2 fuel.
4 Originally it contained Zircaloy-2 for BWRs, Zircaloy-5 4 and M5 for PWRs.
6 The methodology provided for all of the 7
thermal mechanical analysis, which is typical of a 8
fuel performance core. Acceptance review was 9
performed in March 2013, and we accepted the core. We 10 give -- we had PNNL staff as consultants under a 11 contract. And upon review, there were about 70 RAIs, 12 including subparts, was issued. Next please.
13 CHAIR MARCH-LEUBA: Mathew, can you keep 14 the slide 3? I see the cladding materials, Z-2, Z-4, 15 and M5, that are quoted as the Framatome fabricated 16 clads. And I don't remember seeing in the SER any 17 mention of what we call mixed cores, when you have 18 coresident fuel from a different vendor. How do we 19 plan to handle that? Did I miss it in the SER?
20 MR. PANICKER: Mixed core analysis is 21 done, and not as part of this but fuel performance 22 core. That will be under different thermal hydraulics 23 analysis.
24 CHAIR MARCH-LEUBA: So the plan will be to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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26 use the vendor number two thermal mechanical codes for 1
the properties for their fuel?
2 MR. PANICKER: This is for the Framatome 3
fuels.
4 CHAIR MARCH-LEUBA: So this is limited 5
exclusively to analyze Framatome fuel, and if they 6
have a mixed core with a transition with coresident 7
fuel, we'll have to handle it separately?
8 MR. PANICKER: Yeah, that will be handled 9
separately. There are other issues connected with 10 mixed core, because DNBR values, mixed core thermal 11 hydraulics, different pressure drops for different 12 fuel assemblies.
13 CHAIR MARCH-LEUBA: Yeah.
14 MR. PANICKER: All those things are to be 15 considered in the thermal hydraulic analysis.
16 CHAIR MARCH-LEUBA: Yeah, if we can make 17 a recommendation that maybe the SER should -- well 18 it's kind of late, but should be specific that this is 19 only for Framatome fuels. Go ahead, Ron.
20 MEMBER BALLINGER: We need to be a little 21 careful here. This fuel performance code doesn't care 22 who made the fuel. All it cares about is the input 23 parameters. So to the extent that another person's 24 fuel is in the core, they can use this for that. It's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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27 just that the thermal hydraulics part would be 1
different. So there's nothing in this code that deals 2
with anything other than the surface temperature of 3
the clad.
4 CHAIR MARCH-LEUBA: M5 is a proprietary 5
alloy for Framatome. Nobody else can use it.
6 MEMBER BALLINGER: Yeah, sure.
7 CHAIR MARCH-LEUBA: And another vendors, 8
I don't recall, SIRCLO (phonetic) --
9 MEMBER BALLINGER: Oh, you mean other 10 vendors using this model. That's a different --
11 CHAIR MARCH-LEUBA: No, no, no. Framatome 12 using this model to analyze a core that has coresident 13 fuel from Westinghouse.
14 MEMBER BALLINGER: Sure, they don't need 15 anything other than the input parameters for this code 16 to run a fuel performance model.
17 MEMBER KIRCHNER: Yeah, that -- I agree, 18 Ron. That's why I was asking the question about 19 generic. As long as you're staying within the 20 qualified, the validated basis for this methodology, 21 it should not matter.
22 MEMBER RICCARDELLA: Right.
23 PARTICIPANT: But this code might not work 24 for ZIRLO.
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28 MR. GEELHOOD: This code doesn't have any 1
models for other alloys such as ZIRLO.
2 MEMBER BALLINGER: Well, but it's not, 3
you're not asking for approval for that, right?
4 CHAIR MARCH-LEUBA: Well, but if you want 5
to balance a core that has both manufactured fuels, 6
you will have to get a special dispensation to use 7
mixed methods. It pays to think these things in 8
advance before a plant has to do a reload in May --
9 MEMBER KIRCHNER: Well, I would think, 10 Jose, that if you had such a mixed core, you might 11 have to use GALILEO for the Framatome fuel and the XYZ 12 methodology for the other fuel. But --
13 CHAIR MARCH-LEUBA:
That sounds 14 reasonable.
15 MEMBER KIRCHNER: It should still be valid 16 for the fuel assemblies that are being analyzed with 17 GALILEO.
18 CHAIR MARCH-LEUBA: Okay.
19 MEMBER KIRCHNER: It's more the thermal 20 hydraulics domain and the spacer grids and other 21 factors outside of the actual fuel rod mechanical 22 model that would be substantially different when you 23 change fuel bundles or mix fuel bundles.
24 CHAIR MARCH-LEUBA: And a fuel bundle with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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29 M5 performs hydrogen-wise much better than one with 1
Zr-4, or even certainly Zr-2.
2 MEMBER KIRCHNER: Yeah, I agree. So that 3
the complexity would be you would have to use, like I 4
said, the XYZ code for the other fuel.
5 CHAIR MARCH-LEUBA: I think so.
6 MEMBER KIRCHNER: Yeah.
7 MEMBER BALLINGER: I mean, it's the same 8
dance that has to be done if you've got a BWR and 9
you're evaluating instability and you got two 10 different types of fuel.
11 CHAIR MARCH-LEUBA: Yeah, okay. I'm 12 saying -- okay, I'll drop my comment. I was saying 13 that the SER should be more specific that it's only 14 applicable to the cladding of -- that it was intended 15 for.
16 MR. PANICKER: Yes, this is Mathew 17 Panicker, Fuel Analysis Group. For a mixed fuel, we 18 usually have the specification from all the vendors, 19 and they are to do a thermal hydraulic compatibility 20 analysis including the friction factors, pressure 21 drops, et cetera and come out with the margin for 22 pressure drop which is acceptable for the operating 23 and for that fuel to operate in the core, the mixed 24 fuel.
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30 And then there is another way of doing, 1
solving the mixed core problem is characterization 2
analysis. The compatibility of all the fuels with the 3
configuration of the core. Like bypass flow, et 4
cetera, et cetera.
5 CHAIR MARCH-LEUBA: Right, but for some of 6
the acceptance criteria, you need to know how much 7
hydrogen is in the clad. And for that you need to 8
know who manufactured the clad, and you have to use 9
the proper correlation. GALILEO cannot be used to 10 calculate a SIRCLO hydrogen intake.
11 MR. PANICKER: That's right.
12 CHAIR MARCH-LEUBA: Yeah, okay, so I guess 13 we'll cross that bridge -- maybe it's more applicable 14 when we review the ARITA thermal hydraulic and non-15 LOCA transient. Probably the limitation or condition 16 or at least bringing this up belongs more there than 17 here. All right, continue.
18 MR. PANICKER: Next slide, please. The 19 AREVA, as I said before, AREVA revised the scope of 20 the topical report, suspended BWR and MOX fuels in 21 November 2015. And then after that, in June of 2018, 22 after they have looked at the RAIs and et cetera, et 23 cetera, they revised the topical report Revision 1 of 24 ANP-10323 after dropping the MOX and BWR fuels. And 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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31 this is applicable to UO2 and gadolinia fuels, 1
Zircaloy-4 and M5. The methodology provided limited 2
set of thermal-mechanical analyses.
3 Because of the extensive nature of the 4
RAIs, Framatome could deliver it in five installments, 5
starting from December 18 through July 20th. The July 6
20, 2020 was to clarify a limitation condition, couple 7
of limitation conditions in the Safety Evaluation.
8 For review -- during the review, confirmatory 9
calculation were performed using the analysis FRAPCON 10 fuel performance code for comparison with GALILEO.
11 And most of the properties of the GALILEO 12 has been compared with FRAPCON, and you might have 13 seen, the members of the ACRS might have seen that in 14 the Safety Evaluation. There were extensive graphical 15 representation of those comparisons. Next please.
16 So this is some -- the GALILEO is actually 17 built on the COPERNIC PWR cores that just been used in 18 the U.S., and then the German TUV approved CARO-3. It 19 has got models for thermal model and assessment, 20 fission gas release, and its impact on internal 21 pressure of RIP; cladding corrosion and hydriding 22 model; cladding hydrogen pickup; fuel densification 23 and swelling model; mechanical modeling and 24 properties; fuel mechanical properties; rod volume and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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32
-- rod volume model, void volume model and growth 1
assessment; licensing applications.
2 It is not an improved statistical 3
approach, 95% -- 95/95 or better. In most cases, it 4
was 99.9/95 uncertainty calculations and other code 5
applicabilities for fuel performance analysis. Next 6
please.
7 These are the list of guidances and the 8
regulations we used. GDC 10, which applied to SAFDL, 9
which is not exceeding -- is not exceeded during the 10 normal operation and AOOs. Provide emergency core 11 cooling following LOCA, that is usually comes from 12 what you call the fuel performance codes. But in this 13 case, Framatome will submit another application for 14 LOCA analysis. And also 10 CFR 50.46, acceptance 15 criteria for ECCS.
16 10 CFR 50.34 talks about the -- provides 17 guidance for the analysis and evaluation of design and 18 performance of structures, systems, and components.
19 SRP 4.2, which is the guideline for the fuel damage.
20 No damage during AOOs. Fuel damage is not severe to 21 prevent control rod insertion. Number of fuel rod 22 failures not underestimated for proposed accidents.
23 Core coolability should be maintained.
24 And also it -- there were complaints with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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33 SRP 15.02. You cannot say complaints, the guidance in 1
SRP 15.02 is followed because they have provided us 2
with a lot of documentation including theory manual, 3
V&V analysis, and all those things, the evaluation 4
models. And a good explanation for the uncertainty 5
analysis is included in the topical report. Next 6
please.
7 The staff found that the GALILEO code and 8
methodology as described in ANP-10323P Revision 1 and 9
modified as discussed in the RAI responses are 10 acceptable. There are several fuel limitations and 11 conditions regarding the applicability
- rates, 12 methodologies that are not
- approved, and 13 documentation.
14 I think that should be the final slide.
15 CHAIR MARCH-LEUBA: Yes, it is. Thank 16 you, Matt. Anybody has any questions for the staff on 17 the open session? Remember that we'll be seeing 18 details on the closed session in a moment.
19 So Mathew, I just wanted to say that this 20 is a very good SER, very thorough work, very detailed.
21 Lots and lots of confirmatory calculations, which is 22 always good to see. And I congratulate you and your 23 team on an excellent job.
24 MR. PANICKER: Thank you.
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34 CHAIR MARCH-LEUBA: So we are moving now, 1
changing topics completely, we are moving to the BWR 2
division of Framatome. And we're going to be talking 3
about the long-term stability solution for boiling 4
water reactors that the staff has already approved and 5
we reviewed for plant-specific implementation in 6
Brunswick. And now they're submitting a generic 7
topical report with a few modifications.
8 So this is an information meeting and the 9
members will have to provide feedback if we want to 10 issue a letter on it or are we satisfied with the 11 original recommendation for Brunswick and this 12 information meeting.
13 So Doug Pruitt, I believe you are on. You 14 only have a few minutes for the introduction. Doug, 15 I don't see you coming up.
16 MR. PRUITT: Can you hear me now?
17 CHAIR MARCH-LEUBA: Yes.
18 MR. PRUITT: Okay, I was muted from your 19 side. Here we go. I'll unmute you, can you say 20 something?
21 MR. OTTO: Can you see my screen?
22 CHAIR MARCH-LEUBA: I can see the screen.
23 Doug, if you can speak a little louder, you come a 24 little soft.
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35 MR. PRUITT: Okay, can you hear me now?
1 CHAIR MARCH-LEUBA: Perfect, thank you.
2 MR. PRUITT: Okay. Good morning, I am 3
Doug Pruitt, I would like to thank you for this 4
opportunity to brief the changes to the best estimate 5
enhanced Option III methodology from that client-6 specific methodology you reviewed in November.
7 I'm on slide 2, by the way. In this 8
introduction, I will briefly touch on the BEO-III 9
background, basically addressing why would we 10 introduce statistical methodology; a summary of the 11 BEO-III methodology; and a comparison of plant-12 specific and the generic methodology. That's slide 3.
13 The original BWR Owners' Group option III 14 methodology and associated Detect and Suppress 15 hardware was developed and implemented over 25 years 16 ago. And that setpoint methodology was composed of 17 several analytical components, each with its own 18 conservative assumptions.
19 And part of that was because it was a 20 generic methodology that addressed all vendors, and at 21 the time obviously the methodologies and the computer 22 capacity were limited.
23 The compounding of those conservatisms may 24 result in a relatively small margin between normal 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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36 operational noise and the trip setpoint for some 1
plants. It consequently resulted in some spurious 2
reactor scrams. The BEO-III statistical methodology 3
aims to provide conservative reactor setpoints that 4
provide greater operational flexibility to avoid 5
spurious scrams and challenges to the safety systems.
6 Slide 4, please.
7 BEO-III is based on a cycle-specific 8
statistical analysis to determine the bounding 95/95 9
figures of merit criteria and establish the operating 10 limit MCPR for reactor instabilities. Unique to the 11 BEO-III methodology is the greater insight in core 12 design due to the figures of merit. Of course, we do 13 the core MCPR to demonstrate that the safety limit is 14 not challenged at the time of oscillation suppression.
15 We go further and look at the limiting 16 channel hydraulic response to demonstrate that the 17 Detect and Suppress System was not challenged by 18 independent channel oscillations. Slide 5.
19 So what's changed between the plant-20 specific that we talked about last year and the 21 generic LTR?
The correlations, nodalization, 22 numerical solutions, validation against measured data, 23 derivation of modeling uncertainties, statistical 24 analysis, and capability that supports plant-specific 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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37 Detect and Suppress hardware are identical.
1 The changes include one, revision to the 2
numerical basis for
- ICO, independent channel 3
oscillations. Two, introduction of an exposure pre-4 filter to disposition non-limiting exposures from the 5
statistical evaluation. Implementation of a more 6
robust determination of oscillation decay ratios, and 7
an additional analysis step to assess operational 8
flexibility.
9 And that's the conclusion of my open 10 presentation. Any comments, questions?
11 CHAIR MARCH-LEUBA: Hearing none, I just 12 want to say that I've reviewed the BEO-III when we all 13 reviewed it back in the Brunswick application, and I 14 like the fact that it gives more insight into the 15 whole core operation, the whole cycle.
16 Because it analyzes the whole cycle ahead 17 of time and tells you when you may have a problem and 18 when you don't have a problem. As opposed to the old, 19 the 1980s methodologies, which we had to calculate in 20 very conservative numbers and too much conservatism.
21 So I like the -- I want to say thank you 22 for submitting this methodology because I think it's 23 an improvement. Makes the reactor safer and improves 24 the operability.
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38 MEMBER BROWN: Jose, can I ask a question?
1 CHAIR MARCH-LEUBA: Please, go ahead.
2 MEMBER BROWN: Back on slide 3. Second 3
bullet.
4 MR. PRUITT: Yes.
5 MEMBER BROWN:
The compounding of 6
conservatisms results in a relatively small margin 7
between normal operational noise and setpoints for 8
some plants and have resulted in spurious scrams. I 9
understand that statement.
10 In my past battles in my old program, the 11 Naval Nuclear Program, we normally based what I would 12 call removal of -- or having better knowledge of the 13 level of our conservatisms, they were based on data, 14 not on just the desire to redo, you know, to redo the 15 analysis.
16 Is this, when we -- when you talk about 17 removing conservatisms, I understand the desire to 18 prevent spurious scrams. Are they based on test 19 empirical data from fuel performance, or is it just, 20 it is better instrumentation that you know where you 21 are better? As opposed to a ten percent error 22 instrumentation, you now have stuff that's good to one 23 or two percent or four percent?
24 I'm just looking for what's the basis for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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39 being able to improve this performance aspect.
1 MR. PRUITT: Yes, the primary change that 2
results the conservatism of the old method. The old 3
method basically assumes that to arrive at natural 4
circulation at equilibrium conditions, so the 5
feedwater, there's no time element associated with it.
6 And it also assumes that basically you 7
start out the oscillation at some growth ratio. And 8
it was a distribution maybe between 1.0 and 1.4 or 5, 9
I can't remember exactly. And that was what 10 established the hot-channel oscillation magnitude.
11 By going to a full simulation of the pump 12 trip and the feedwater temperature equilibration, you 13 start your detection of oscillations at a much lower 14 magnitude, basically when it's becoming unstable. And 15 so your system is able to respond much faster in a 16 real transient simulation than it is in the 17 conservative kind of steady state approximations.
18 MEMBER BROWN: Well, okay, but how are you 19 able to get it lower? Is that because your 20 measurements allow you to do that?
21 MR. PRUITT: Well, the other system 22 assumes that you start detecting the oscillations when 23 you're at a growth ratio of 1.l, 1.2, 1.3, whatever 24 would be at that equilibrium condition. And so you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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40 still then have to wait for it to get to the number of 1
counts in the oscillation magnitude in order to trip 2
the system. In reality, it starts counting 3
oscillations and monitoring when you cross the 4
boundary.
5 And it's a much slower process where you 6
start out at 1.0 and it slowly increases in growth 7
rate as the feedwater equilibrates. And so basically 8
the protection system is armed and ready to trip the 9
reactor at a much lower or much earlier in the 10 oscillation growth.
11 CHAIR MARCH-LEUBA: Doug, would you say 12 that -- I mean, the detection system has not changed.
13 We have the same detection system --
14 MR. PRUITT: Right.
15 CHAIR MARCH-LEUBA: -- before and after.
16 The main difference is that now you're doing a best 17 estimate calculation of what actually happens in the 18 reactor, versus assuming the worst possible scenario.
19 MEMBER BROWN: Okay, I got that. So but 20 is that -- is the best estimate then being used for 21 design basis accident considerations or for beyond 22 design basis considerations?
23 MR. PRUITT: Well, this is treated as a 24 regular AOO, so this is --
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41 CHAIR MARCH-LEUBA: It is always a pump 1
trip, correct, Doug?
2 MR. PRUITT: Correct, yeah.
3 CHAIR MARCH-LEUBA:
So it's a
4 recirculation pump trip.
5 MEMBER KIRCHNER: Yeah, Charlie, this is 6
in an AOO category of events for BWR.
7 MR. PRUITT: Yeah, we treat it as an 8
Anticipated Operational Occurrence. We have separate 9
methodologies based on the same code for anticipated 10 transients without scram and an instability.
11 MEMBER BROWN: Okay, thanks.
12 CHAIR MARCH-LEUBA: Excellent. Any more 13 comments in the open session? I'll count to five.
14 I'll say no, so can we open the public line. Any 15 members participating in the conference, in the Skype 16 conference or the public line, could you, if you want 17 to make a comment, please do so right now.
18 Can we have a confirmation the public line 19 is open, Thomas? I don't hear anything. Anybody at 20 all that wants to make a comment, please do so now, 21 the next five seconds.
22 Good, so this concludes the open session 23 of the meeting. We're going to transfer to the closed 24 session to discuss proprietary information to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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42 Framatome. And we are going to try to use a different 1
process today than we've used in the past.
2 The closed meeting is being controlled by 3
some gatekeepers, and they are the ones that will let 4
you in if they determine that you belong inside, that 5
you have a need to know for this proprietary 6
information.
7 So we will reconvene at 10:35, which is 8
seven minutes from now, on the closed session. And it 9
will take a little while to let everybody through the 10 log-in. So thank you very much for --
11 MEMBER KIRCHNER: Jose, could we have a 12 few more minutes than seven minutes?
13 CHAIR MARCH-LEUBA: Yeah, I just didn't 14 want to run over one, but you're right. Let's start 15 at 10:45. Because it will take that long to let 16 everybody in.
17 MEMBER KIRCHNER: Much obliged.
18 MEMBER BALLINGER: This is Ron, we have a 19 second invitation, is that correct?
20 CHAIR MARCH-LEUBA: That is correct. And 21 it starts with capitals closed meeting.
22 MEMBER BALLINGER: Yeah, yeah, okay.
23 CHAIR MARCH-LEUBA: Yeah, okay, so this 24 phone line should go dead because there is no business 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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43 to be had here. So everybody that belongs in the 1
closed meeting, please move to the closed meeting. So 2
we are temporarily recessed, and we will reopen the 3
meeting later on, at 10:45.
4 MEMBER BROWN: So we'll reopen this 5
meeting later also after? We're going to have 6
another open session, or is the rest of the day on 7
closed?
8 CHAIR MARCH-LEUBA: We, ACRS, will have a 9
completely different topic this afternoon at 2:00 p.m.
10 MEMBER BROWN: Oh, no, I understand that, 11 but for your purposes, we're going to be in closed for 12 your subcommittee meeting.
13 CHAIR MARCH-LEUBA: We will be closed for 14 the rest of the morning, until 1:00.
15 MEMBER BROWN: Okay, thank you, thank you.
16 (Whereupon, the above-entitled matter went 17 off the record at 10:29 a.m.)
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1 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Chris Allison September 24, 2020 ACRS Sub-committee Meeting Topical Report ANP-10323P GALILEO
2 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Topics
Background
Overview of Topical Report GALILEO Fuel Performance Code Statistical Evaluation Methodology Advanced Methods Platform
3 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020
Background
Development of GALILEO initiated to consolidate Framatomes worldwide expertise and experience into a single fuel performance code Builds upon the best practices and techniques from Framatomes current generation of fuel performance codes and methods, including:
- COPERNIC (France and US)
- RODEX4 (US)
- CARO-3E (Germany)
Originally developed to support PWR and BWR applications for UO2, gadolinia and MOX fuels Requested NRC approval for
- PWR applications
- UO2 and gadolinia fuel types
- M5 and Zr-4 cladding
4 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Overview of Topical Report Describes a methodology for the realistic evaluation of the thermal-mechanical performance of fuel rods for PWR applications The methodology is for demonstrating compliance with many of the fuel rod requirements of Section 4.2 of NUREG-0800 Two major components:
- GALILEO fuel performance code
- Statistical evaluation methodology Topical report describes the following aspects
- Requirements and capabilities
- GALILEO calibration, validation, and range of parameters
- Uncertainty analyses
- Demonstration analyses
5 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 GALILEO Fuel Performance Code Best-estimate fuel rod performance code Simulates the thermal and mechanical response of a fuel rod in a reactor core as a function of exposure for the local power and flow conditions encountered during reactor operation Phenomenological rate dependent models evaluate the temperature, strain, exposure dependent changes in the state of the fuel and cladding materials, and the release of fission gas products Includes modeling of
- Thermal conductivity degradation with burnup
- Enhanced fission gas release in transients and at high burnup
- Formation of high burnup structure on pellet rim
- Advanced pellet mechanical models Calibrated and validated to an extensive fuel performance database consisting of European and U.S. data
6 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Statistical Evaluation Methodology Analyze fuel rod performance during normal operating and AOO conditions for a given fuel reload and power plant Considers the uncertainties over the projected range of fuel operation for the rods in the core (power histories), the measured and calculated power uncertainties, the manufactured fuel rod characteristic uncertainties, and the GALILEO model uncertainties Employs a random sampling of the power, manufacturing, and model uncertainties, similar to Monte Carlo, with the best-estimate GALILEO code in conjunction with non-parametric statistics to evaluate the propagation of the uncertainties to the design analysis results Demonstrate that the fuel meets the design criteria with a quantified probability
7 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Advanced Methods Platform GALILEO is a foundational piece in Framatomes platform of advanced technologies and methods, including
- PWR Rod Ejection Accident (REA) analysis - NRC approved methodology
- Supports RG 1.236
- Non-LOCA transient analysis - in NRC review
- LOCA analysis methods - future submittal
- Advanced Fuel Management (AFM) - future submittal(s)
- Increased burnup
- Higher enrichment
- Enhanced Accident Tolerant Fuel (EATF) - future submittal(s)
8 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Acronyms ACRS - Advisory Committee on Reactor Safeguards AFM - Advanced Fuel Management AOO - Anticipated Operational Occurrence BWR - Boiling Water Reactor EATF - Enhanced Accident Tolerant Fuel LOCA - Loss of Coolant Accident MOX - Mixed Oxide PWR - Pressurized Water Reactor REA - Rod Ejection Accident RG - Regulatory Guide
9 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 CARO-3E, COPERNIC, GALILEO, M5Framatome, M5, and RODEX4 are trademarks or registered trademarks of Framatome or its affiliates, in the USA or other countries.
Trademarks
10 ACRS Sub-committee Meeting Topical Report ANP-10232P GALILEO-September 24, 2020 Thank you
NRC EVALUATION OF GALILEO CODE AND METHODOLOGY TOPICAL REPORT ANP-10323 REVISION 1 OPEN SESSION Mathew Panicker Ph.D., P.E.
Nuclear Methods and Fuel Analysis Branch NRR/DSS/SFNB ACRS Subcommittee Meeting September 24, 2020
Review of GALILEO Fuel Rod Thermal-Mechanical Code and Methods 2
Mathew Panicker (NRC)
Technical Review provided by PNNL under contract with NRC
- Ken Geelhood
- Dion Sunderland
- Christine Goodson
- Carl Beyer
- Robert Montgomery Review focus
- GALILEO Code
- Assessment of individual models
- Assessment of integral code predictions
- GALILEO Methodology
- Assessment of proposed uncertainties
- Assessment of statistical methodology
- Assessment of fuel damage limits
Overview and History 3
Revision 0 of ANP-10323 (GALILEO) submitted in October 2013 Realistic evaluation of the thermal-mechanical performance of fuel rods for Pressurized Water Reactors (PWRs).
- Applicable to PWR, BWR and MOX fuels
- UO2, burnable absorbers
- Zircaloy-2, Zircaloy-4, M5
- Methodology provided for all thermal-mechanical analyses Acceptance review was performed by NRC staff, March 2014 PNNL staff supported the technical review under contract NRC-HQ-20-14-T-0009 under technical supervision of NRC staff Upon review, over 70 RAIs (including sub-parts) were issued
Overview and History (Contd.)
4 AREVA revised the scope of TR, suspended BWR and MOX fuels, November 2015 Framatome submitted ANP-10323 Revision 1 for PWR fuels June 2018 (Applicable to PWR fuel, UO2 and UO2-Gd2O3,
Zircaloy-4 and M5, Methodology provided for limited set of thermal-mechanical analyses Framatome responded to RAIs in five installments; 12/18, 1/19, 6/19, 9/19,, 5/20, and 7/20 For the review confirmatory calculations were performed using the NRCs FRAPCON fuel performance code for comparison to GALILEO
Areas Covered in GALILEO 5
Areva (Framatome) submitted GALILEO topical report in August 2013 GALILEO is Built upon NRC-approved COPERNIC and German TUV approved CARO-3
- Thermal model and assessment
- Fission gas release (FGR) model and its impact on internal pressure (RIP) model
- Cladding corrosion and hydriding model
- Cladding hydrogen pickup
- Fuel densification and swelling model
- Mechanical modeling and properties; Fuel Mechanical properties
- Rod void volume model and growth assessment
- Licensing applications
- Improved statistical approach
- 95%/95% or better approach for uncertainty calculations
- Code applicability
Regulatory Evaluation 6
GDC 10: SAFDLs not exceeded during NO and AOOs GDC 35: Provide emergency core cooling following LOCA 10 CFR 50.46 Acceptance criteria for ECCS 10 CFR 50.34 Analysis and evaluation of design and performance of structures, systems, and components SRP 4.2: No damage to fuel during NO and AOOs
- Fuel damage not severe to prevent control rod insertion
- Number of fuel rod failures not underestimated for PAs
- Core coolability is maintained Compliance with SRP 15.02; documentation, code verification and validation, evaluation model, uncertainty analysis included
Conclusions in SE 7
NRC finds GALILEO code and methodology as described in ANP-10323P Revision 1 and modified as discussed in RAI responses to be acceptable Several limitations and conditions were stated regarding applicability range, methodologies that are not approved, and documentation
Acronyms 8
AOO - Anticipated Operational Occurrences BWR - Boiling Water Reactor ECCS - Emergency Core Cooling Systems LOCA - Loss of Coolant Accident MOX - Mixed Oxide NO - Normal Operations RAI - Request for Additional Information SAFDLs - Specified Acceptable Fuel Design Limits UO2 - Uranium Dioxide
1 Generic BEO-III - ACRS Information Meeting - September 24, 2020.
Doug Pruitt ACRS Information Meeting - September 24, 2020 Best-estimate Enhanced Option III (BEO-III)
Open-Session
2 Generic BEO-III - ACRS Information Meeting - September 24, 2020.
BEO-III Background Summary of BEO-III Methodology Comparison of Plant-Specific and Generic Methodology Outline
3 Generic BEO-III - ACRS Information Meeting - September 24, 2020.
The original BWROG Option III methodology and associated Detect and Suppress (D&S) hardware were developed and implemented over 25 years ago.
- The setpoint methodology was composed of several analytical components each with its own conservative assumptions.
The compounding of conservatisms result in a relatively small margin between normal operational noise and the trip setpoint for some plants and consequently have resulted in spurious reactor scrams.
The BEO-III statistical methodology aims to provide conservative reactor setpoints that provide greater operational flexibility to avoid spurious reactor scrams and challenges to the safety systems.
BEO-III Background
4 Generic BEO-III - ACRS Information Meeting - September 24, 2020.
BEO-III is based on cycle-specific statistical analyses to determine the bounding 95/95 figures of merit (FoM) and establish the OLMCPR for reactor instabilities Unique to the BEO-III methodology is the greater insight into the core design due to the selected FoM.
- Core MCPR to demonstrate that the Safety Limit is not challenged at the time of oscillation suppression
- Limiting channel hydraulic response to demonstrate that the D&S system is not challenged by independent channel oscillations (ICO)
The BEO-III methodology has been reviewed previously as a plant specific methodology Summary of BEO-III Methodology
5 Generic BEO-III - ACRS Information Meeting - September 24, 2020.
Correlations, nodalization, numerical solutions are identical.
Validation against measured data and derivation of modeling uncertainties is identical Statistical analysis is identical Both support plant specific D&S hardware Changes include:
- Revision to the numerical basis for ICO
- Introduction of an exposure pre-filter to disposition non-limiting exposures from the statistical evaluation
- Implementation of a more robust determination of oscillation decay ratios
- Additional analyses step to assess operational flexibility Comparison of Plant-specific and Generic Method