ML23339A138
| ML23339A138 | |
| Person / Time | |
|---|---|
| Issue date: | 11/02/2023 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| NRC-2589 | |
| Download: ML23339A138 (1) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
710TH MEETING, ADVISORY COMMITTEE ON REACTOR SAFEGUARDS Docket Number:
N/A Location:
teleconference Date:
11-2-2023 Work Order No.:
NRC-2589 Pages 1-128 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1716 14th Street, N.W.
Washington, D.C. 20009 (202) 234-4433
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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
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UNITED STATES OF AMERICA 2
NUCLEAR REGULATORY COMMISSION 3
+ + + + +
4 710TH MEETING 5
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 6
(ACRS) 7
+ + + + +
8 THURSDAY 9
NOVEMBER 2, 2023 10
+ + + + +
11 12 The Advisory Committee met via Video 13 Teleconference, at 8:30 a.m. EDT, Joy L. Rempe, 14 Chairman, presiding.
15 16 COMMITTEE MEMBERS:
17 JOY L. REMPE, Chairman 18 WALTER L. KIRCHNER, Vice Chairman 19 DAVID A. PETTI, Member-at-Large 20 RONALD G. BALLINGER, Member 21 VICKI M. BIER, Member 22 CHARLES H. BROWN, JR. Member 23 VESNA B. DIMITRIJEVIC, Member 24 GREGORY H. HALNON, Member 25 JOSE MARCH-LEUBA, Member NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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ROBERT P. MARTIN, Member 2
THOMAS E. ROBERTS, Member 3
MATTHEW W. SUNSERI, Member 4
5 ACRS CONSULTANT:
6 DENNIS BLEY 7
DESIGNATED FEDERAL OFFICIAL:
9 ZENA ABDULLAHI 10 11 ALSO PRESENT:
12 PHILIP BENAVIDES, NMSS 13 JAMES CORSON, RES 14 ELIJAH DICKSON, NRR 15 SCOTT KREPEL, NRR 16 LISETTE MADALENA, Interpreter 17 JOSEPH MESSINA, NRR 18 CHARLEY PEABODY, NRR 19 JASON PIOTTER, NMSS 20 ASHLEY SMITH, NRR 21 JENNIFER WAGNER, Interpreter 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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P R O C E E D I N G S 2
8:30 a.m.
3 CHAIR REMPE: So good morning. Its 8:30 4
on the East Coast, and this meeting will now come to 5
order. This is the second day of the 710th meeting of 6
the Advisory Committee on Reactor Safeguards.
7 Im Joy Rempe, Chairman of the ACRS.
8 Other members in attendance are Ron Ballinger, Vicki 9
Bier, Vesna Dimitrijevic, Greg Halnon, Walt Kirchner, 10 Jose March-Leuba, Robert Martin, Dave Petti, Tom 11 Roberts, Matthew Sunseri. And well soon be joined 12 Im sure by Member Brown. Hes probably delayed in 13 traffic.
14 I note we have a quorum. Similar to 15 yesterday, the committee is meeting in person and 16 virtually. A communications channel has been opened 17 to allow members of the public to monitor the 18 committees discussion. Ms. Zena Abdullahi is the 19 Designated Federal Officer for todays meeting.
20 During todays meeting, the committee will 21 consider the following topic: increased enrichment 22 rulemaking regulatory basis. Its requested that 23 speakers identify themselves and speak with sufficient 24 clarity and volume so they can be readily heard.
25 Additionally, participants should mute NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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themselves when not speaking. At this time, I would 2
like to ask other members if they have any opening 3
remarks. And not seeing or hearing any, then Id like 4
to ask Member Ron Ballinger to lead us in our first 5
topic for todays meeting.
6 Ron.
7 MEMBER BALLINGER: Thank you, Chairman.
8 I would like to make a few opening remarks.
9 Todays presentation is going to be -- is 10 a bit unusual. At our subcommittee meeting we had a 11 lot of questions and answers back and forth on this 12 topic, especially related to FFRD. And subsequent to 13 that, weve had a few conversations back and forth.
14 And so the staffs presentation today will 15 be more -- in more detail than we would expect for a 16 full committee meeting to make sure that members that 17 were not present at the subcommittee are completely up 18 to speed on the issues and have their opportunities to 19 ask questions.
20 And our options, usually wait until after 21 the presentation for the discussion. Our options are 22 likely to be write a letter today or at this time, but 23 public comments have not been received, primarily from 24 industry, on this document. And they have not been 25 incorporated into the document but will be NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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incorporated when the rule is issued. Those comments 2
will be incorporated.
3 So we have not had the advantage of having 4
those comments for our deliberation. So the second 5
option would be to wait until the rule, draft rule is 6
issued, where we get another chance to review it. At 7
which time, the industry public comments would be 8
incorporated.
9 So thats where we are. That time would 10 be well into 2024, I think, if we choose to do that.
11 So members, please keep these options in mind as we 12 listen to their presentation, and hopefully the 13 discussions after that will be -- will give us some 14 idea on the best path forward.
15 So I dont know whether the staff wants to 16 make an initial statement or not.
17 MR. KREPEL: This is Scott Krepel speaking 18 through a sign language interpreter. I am the Branch 19 Chief of the Nuclear Methods and Fuel Analysis Branch, 20 and Im happy to see all of you in person again. So 21 I will give some short remarks. I dont want to take 22 up too much of our time.
23 But the increased enrichment rulemaking 24 has been approved to move forward for the regulatory 25 framework in order to support industry and a federal NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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goal of moving towards a carbon-free economy. This is 2
a significant initiative for a lot of people, and this 3
effort involves multiple offices and divisions 4
throughout the NRC.
5 My branch is only one specific section of 6
it for fuel fragmentation, relocation, and dispersal.
7 But Ive heard thats whats made most people excited.
8 And I want to emphasize that we are making 9
no recommendation in the reg basis. Because we 10 believe that this is so important and complex that we 11 needed to get -- we need to get stakeholders input 12 before moving forward with a recommendation.
13 But to be honest, we threw everything into 14 the kitchen sink in this reg basis in order to 15 consider a wide range of different options. I look 16 forward to hearing what you all have to say after my 17 staff provides their presentation, and thank you for 18 giving me the opportunity to provide some remarks.
19 CHAIR REMPE: Ron?
20 MEMBER BALLINGER: Yes, maam.
21 CHAIR REMPE: When we had our subcommittee 22 meeting, we heard there was going to be a meeting on 23 October 25 --
24 MEMBER BALLINGER: Yeah, I was about to 25 mention.
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CHAIR REMPE: And yeah, I dont see 2
anything in the slides about it. And yes, I think it 3
would be better than just looking at it and trying to 4
interpret and reading the transcript what the staff 5
thinks. Did they get some significant comments --
6 MEMBER BALLINGER: They did.
7 CHAIR REMPE: From industry at that time, 8
and could the staff or perhaps Scott provide us their 9
thoughts about those industry comments? Were there a 10 lot of people saying hey, wait to publish this 11 regulatory basis until you hear our official comments?
12 Did you -- or did they say yeah, this looks pretty 13 good? Or what happened?
14 MEMBER BALLINGER: I mentioned that to 15 them and asked if we can get access quickly to the 16 results of that public meeting. Because there were 17 public comments by the industry.
18 CHAIR REMPE: Okay, well, Id like to hear 19 it, not just have access to it because were supposed 20 to be starting the letter-writing today. So I hope 21 the staff will include this in their discussions 22 today, because I dont see any slides on that.
23 MR. BENAVIDES: Yeah, we did receive some 24 comments. Most of the questions that came, theyre 25 more clarity, trying to understand what the regulatory NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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basis or the process forward. I dont know if some of 2
the tech staff, I know we have Elijah and Joe Messina 3
here, Elijah Dickson and Joe Messina here, that maybe 4
their topics. Because theres more I guess questions 5
related to their topics.
6 But the regulatory basis is published.
7 Just kind of where we are in that, its published.
8 This is part of our normal process. This is the 9
clarity.
10 Really, it was an introduction of hey, 11 this is work we did in the public meeting, you know, 12 in the regulatory basis. And then it was inform the 13 public on how to go forward to provide, you know, 14 comments to be considered as we developed the proposed 15 rule.
16 And so a lot of the feedback was on that.
17 There were some clarifying questions, so --
18 CHAIR REMPE: Ill be a little more 19 specific. Your regulatory basis document said you 20 were waiting to finalize your recommendation for FFRD 21 until you receive public input so you can consider 22 those comments and determine if any changes need to be 23 made or if you can make a recommendation.
24 Did you receive enough comments in the 25 public meeting to move forward on that finalization of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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your recommendation?
2 MR. BENAVIDES: No, we have not.
3 CHAIR REMPE: Okay.
4 MR. BENAVIDES: Because well receive 5
those, the public comment period, which is going --
6 scheduled today, as of November 22. We did receive an 7
extension request that were evaluating. That would 8
be for an additional two months. And so we will --
9 what we typically do as part of the process is we wait 10 for those comments to come in and hold.
11 Because we recognize that while a lot of 12 parties are engaged and want to be there at the public 13 meetings, there are others that provide input that may 14 not be available that day. And so we will wait for 15 that comment period to close before we consider and 16 move forward.
17 CHAIR REMPE: Thank you.
18 MR. BENAVIDES: Youre welcome.
19 MR. KREPEL: And this is Scott. I just 20 want to say something really quickly. Typically an 21 organization like NEI will provide their public 22 comment on the final day. And theyll take a lot of 23
-- they take a lot of time to collect feedback from 24 different stakeholders and discuss amongst themselves.
25 So it could be close to the final time NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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period before they actually get comments. And we 2
wont know enough until the final day until the public 3
comment time period is over.
4 MR. BENAVIDES: And just to add onto that, 5
as part of the request we received for the public 6
extension request that theres industry did desire 7
more time to evaluate the topics. Because we are 8
asking a lot of questions, especially in the FFRD and 9
the control room design criteria, and industry wanted 10 to have time to digest that, consider it, and be able 11 to respond appropriately.
12 CHAIR REMPE: Thank you.
13 MEMBER BALLINGER: Okay, we can proceed, 14 I think.
15 MR. BENAVIDES: Next slide, please.
16 MEMBER BALLINGER: Youll have to hunker 17 up to the microscope, or to the --
18 MR. BENAVIDES: Sorry. Thank you for your 19 time. Im Phil Benavides, Im the project manager in 20 the Office of Nuclear Materials Safety and Safeguards, 21 project manager for this rulemaking on the increased 22 enrichment conventional and accident-tolerant fuel 23 designs in light water reactors.
24 Today we are going to provide an overview 25 of the increased enrichment regulatory basis, which NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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was noticed in the Federal Register on September 8.
2 The overview will begin with a brief overview of the 3
increased enrichment rulemaking, which will be in the 4
presentations from the relevant subject matter experts 5
for each of the regulatory basis technical topics.
6 Next slide, please.
7 With that, Im going to provide an 8
overview of the increased enrichment rulemaking.
9 Slide 5, please.
10 As a reminder, this slide shows our 11 typical rulemaking process. We are still in the 12 second box, denoted by the yellow star, where we have 13 issued a regulatory basis on September 8 and are in 14 the public comment period.
15 I wanted to use this slide to point out 16 that the team is engaging with ACRS earlier than 17 normal, due to the complexity of this rulemaking.
18 This engagement along with public comments received 19 will help inform the development of the proposed rule.
20 With that said, I do want to point out the 21 additional opportunities for ACRS engagement, denoted 22 by the blue triangles. ACRS will have, as you know, 23 ACRS will have an opportunity to engage in the 24 proposed rule prior to the rule being sent up to the 25 Commission for consideration.
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In addition, ACRS will have an opportunity 2
to engage towards the end of the final rule 3
development, which will be prior to the final rule 4
being sent to the Commission for consideration as 5
well. Next slide, please.
6 As a way to provide background on how we 7
got to this point, Id like to go back to the 8
beginning when the issue was identified. Throughout 9
the last few years, staff has seen an increased 10 interest from industry for the use of fuel enriched 11 above 5%, U-235.
12 The NRC noted that although the current 13 regulatory framework allows for the licensee to fuel 14 above 5 weight percent, the use of this fuel may 15 result in numerous exemption requests for licensees.
16 So as a proposed solution, NRC staff began 17 pursuing rulemaking rather than licensing by 18 individual exemption. In December of 2021, the staff 19 provided the Commission with SECY-21-0109, requesting 20 approval to begin the rulemaking process. The 21 Commission granted this approval in SRM-SECY-21-0109 22 in March of 22, 2022.
23 The Commission also specified several 24 considerations to evaluate in addition to what was 25 specified in the rulemaking plan. These are NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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addressed, fuel fragmentation, relocation and 2
dispersal. Take a risk-informed approach. And we 3
should also engage with stakeholders to develop the 4
regulatory guidance.
5 Slide 7 --
6 MEMBER MARTIN: Question.
7 MR. BENAVIDES: Sure.
8 MEMBER MARTIN: From Member Martin. Like 9
understand implications of a kind generic resolution.
10 In my experience, generic can go a couple paths. One, 11 you can just put something generic and put the burden 12 on the applicant. Or normally, you might try to solve 13 a lot of problems at a time.
14 And if you do that, obviously theres a 15 lot of up-front costs, you know, due diligence on 16 that. What is your vision, or what do you mean by 17 generic in this particular case? Is it just, you 18 know, another catchphrase to eliminate the exemption 19 approach that, you know, and youre just using it kind 20 of at a high level?
21 Or anyway, just explain. It comes up a 22 few times in the report, so.
23 MR. BENAVIDES: Okay. Youre talking 24 about the -- and just to make sure, I will repeat 25 back. Our approach forward with this rulemaking, what NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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we do to avoid those exemptions going forward.
2 With those in a lot of the topics we do 3
have, were going to change the rules where there --
4 where theres areas where -- in the regulations where 5
theres caps at 5%. Were going to evaluate those and 6
make sure that is appropriate to raise them beyond 5%
7 up to less -- up to but less than 20%.
8 And so for example, in 71.55, you know, 9
were looking at a portion of that where its in 10 there. And were realizing that, you know, maybe its 11 not needed. Or in 50.68 for the criticality one, you 12 know, requirements, the 5% criteria.
13 Were looking at that. I think the path 14 forward with that is to -- the path forward with that 15 is to remove the 5% and really point to the k-16 effective being less than.95, you know,.95. You 17 know, and kind of looking at the criteria that may be 18 more --
19 MEMBER MARTIN: I think the rub, Bob, is 20 that it gets into the fuel dispersion (audio 21 interference) and whether something gets snuck in 22 there and then is there -- I see a lot of statements 23 about research, your research.
24 And you start thinking -- you know, 25 piecing the generic and research, and they start NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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seeing a process that goes way out in time. And at 2
the same, generic doesnt include non-light water 3
reactors. Thats explicit in the report.
4 So anyway, theres an ambiguity I think 5
with the term and that Im responding to. But yes, if 6
we go back to the SECY, it says something to the 7
effect that it's generic so that its a, you know, a 8
more straightforward process that we get through 9
quickly.
10 And I guess when I saw the research aspect 11 to it, I started to wonder whether, you know, it was 12 a little bit of scope creep coming into play.
13 MR. BENAVIDES: Right, and you know, I 14 would point out the FFRD topic was not part of the 15 rulemaking plan that went --
16 MEMBER MARTIN: Okay.
17 MR. BENAVIDES: And so that is something 18 that the staff has done a great job. And theyre 19 trying to manage that. But as with our regulatory 20 basis, we put forth there proposed alternatives that 21 the staff has come up with for consideration.
22 But we have put out for the public to 23 provide, you know, feedback on that so we can be 24 informed as we move forward with --
25 (Simultaneous speaking)
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MEMBER MARTIN: Its good to know what you 2
said there in 21, that the fuel dispersion wasnt 3
necessarily part of that earlier vision, but now its 4
in there. For good reason. But there is a little bit 5
of added risk introduced. Thank you.
6 MR. BENAVIDES: No, thank you. All right, 7
thank you, were on slide 7.
8 Just the status of the rulemaking 9
activity. The NRC issued the regulatory basis on 10 September 8, as stated earlier.
11 This regulatory basis discusses the 12 regulatory issues, alternatives, and new alternatives 13 to resolve them. Considers legal, policy, and 14 technical issues. Considers the cost and benefits of 15 each alternative. And identifies the NRC staffs 16 recommended alternative in most regulatory issues, 17 with the FFRD being an outlier, which will wait for 18 additional public input received during the public 19 comment period.
20 Stakeholder involvement includes public 21 meetings, which were held in June 22 of 2022 and last 22 week, October 25, and the public period, which is 23 currently open til November 22. Once again, Id like 24 to point out that we have received an extension 25 request that is under consideration.
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And then just to point out, just per the 2
timeline, the proposed rule is due to the Commission 3
December 2024.
4 VICE CHAIR KIRCHNER: Philip, maybe this 5
is a good to follow on Bobs comments. For the court 6
reporter, this is Walt Kirchner.
7 When you say generic, what Im thinking of 8
is you look at the existing regulations that are 9
applicable to the issue of what level of enrichment.
10 And on your previous slide, you made it clear you were 11 dealing with LWRs.
12 But if you do this generically, and I am 13 advanced reactor concept, then I can point to these 14 changes in the rules, whether it shows up in 50 or 52 15 or shows up in the 70 series, or wherever enrichment 16 is addressed in the existing reg structure. Then Im 17 okay.
18 What bothers me is the constant LWR for 19 every -- not just for your activity, but we see this 20 across the board. We get this distinct non-LWR 21 proposals and LWR proposals. But if this is truly 22 generic, then this just opens the door for anyone who 23 wants to go way up to 20% enrichment, or whatever 24 level you set in your rulemaking.
25 MR. BENAVIDES: Yeah, the rulemaking is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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focused on light water reactors.
2 VICE CHAIR KIRCHNER: No, I understand 3
that, yeah. But when you changed the regulations, 4
that opens the door for non-LWRs to take advantage, 5
avail themselves of that. Is that correct? Yeah.
6 MR. BENAVIDES: Yeah.
7 VICE CHAIR KIRCHNER: Yeah, okay, fine.
8 So it is generic in that sense. Right, okay, go on.
9 Thank you.
10 MR. BENAVIDES: Okay. Next slide, please.
11 And heres the topics, regulatory basis topics that 12 will be discussed in detail by our NRC subject matter 13 experts. Charlie Peabody will discuss criticality and 14 accident requirements in 10 CFR 50.68.
15 With Don Palmrose unavailable today, Ill 16 provide a brief overview of both environmental topics 17 in 10 CFR 51.51 and 51.52. Jason Piotter will discuss 18 general requirements for fissile material packages in 19 10 CFR 71.55.
20 Elijah Dickson will discuss control room 21 requirements in 10 CFR 50.67 and GDC-19. Joe Messina 22 and Ashley Smith will discuss the topic of fuel 23 dispersal.
24 And with that, unless there are any 25 additional questions on the rulemaking overview, we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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can move on to the technical topic presentations.
2 All right, thank you for your time.
3 Hearing none, Charlie Peabody will present on 50.68.
4 MR. PEABODY: All right, this is Charlie 5
Peabody. Can everyone hear me?
6 SPEAKER: Yes, youre fine.
7 MR. PEABODY: All right, next slide, 8
please, Aaron.
9 So the area I looked at was 10 CFR 50.68.
10 This is a rule that essentially uses k-effective 11 acceptance criteria with required probability and 12 confidence levels to permit exemptions to 70.24 13 activity criticality monitoring and emergency planning 14 requirements.
15 This rule has a condition in it. Its 16 50.68(b)(7), which limits the application of this rule 17 to 5 percent weight U-235. This limit is, you know, 18 distinct from the B(2), B(3) and B(4) paragraphs, 19 which are the ones that actually specific the k-20 effective acceptance criteria.
21 I want to be clear that like were looking 22 at changing the enrichment paragraph, but we plan on 23 maintaining the k-effective acceptance criteria at 24 their existing criteria, probability, and confidence 25 levels. Next slide.
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MEMBER MARTIN: Question. This Bob Martin 2
again. The 5%, the original basis for the 5%
3 enrichment limit I would think, in part, given how old 4
it is probably, that there was some testing done, 5
criticality testing or at least some sort of database.
6 And it would have covered up to 5%. Maybe it 7
addressed certain handling scenarios, what have you.
8 What little I know about testing and 9
criticality, I dont think theres a ton of testing 10 beyond 5%. Have you thought about the necessity for 11 looking at this question of criticality testing for 12 higher enrichments?
13 MR. PEABODY: So when you used the term 14 testing, you know --
15 MEMBER MARTIN: Physical testing.
16 MR. PEABODY: Yeah, we are doing a 17 research study that, you know, models the higher 18 enrichments, but we havent done physical testing on 19 this. In part because, you know, we dont readily 20 have access to material thats enriched beyond 5%.
21 And many of the other parts of this rule will 22 facilitate, you know, that becoming more available.
23 I will just say, like Ive kind of thought 24 about too, you know, like if -- as you do extrapolate 25 out, you know, with the calculations, at some point it NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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might just be easier to actually do a physical test to 2
determine what your multiplication is in the spent 3
fuel pool and apply it to the same limit. But thats 4
not what weve been seeing so far.
5 And also, if we go on to the next slide 6
just for this particular point, the way that we 7
analyze and apply 50.68 as part of our fuel transition 8
LAR process, so its something that we look at in 9
advance.
10 A licensee would have to furbish a -- or 11 Im sorry, an applicant would have to furbish a 12 justification that they can safely apply 5 percent 13 weight in their new and spent fuel storage facilities 14 before we approved their use of that fuel and let that 15 fuel be delivered to their site.
16 MEMBER MARTIN: So to follow up, theres 17 a possibility that the applicant might need to, say, 18 invest in some criticality testing. I mean, because 19 codes, Im a code guy my whole life, but codes lie.
20 And theres nothing better than testing.
21 But would you agree that theres the 22 possibility that there might be some burden associated 23 with criticality testing? I mean, we already know 24 theres going to be some burden with fuel designs 25 anyway, there always has been an issue.
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MR. PEABODY: Yeah, another particular 2
with that is that, you know, the codes are always 3
going to assume that the spent fuel pool is completely 4
up to whatever their maximum capacity is on this.
5 And like even if you could get some 6
testing measurements, it may, like its going to 7
produce the same output, but it may not -- it may only 8
validate part of the code. It may not validate the 9
entire code. So thats another challenge with that.
10 But obviously the active criticality 11 monitoring part of this is what initially led to the 12 50.68 methodology, and that was implemented in 1998, 13 to kind of give you an idea of the timeframe that this 14 research was performed.
15 Like, if the whole point of it is to have 16
-- is to not have to have active criticality 17 monitoring, then obviously like performing that test 18 kind of becomes the thing that they wanted to avoid.
19 So if they have that, then the only real 20 gain from this is that they wouldnt have to do some 21 of the emergency planning drills if they could 22 demonstrate that the criticality -- that the margin to 23 criticality was below the acceptance criteria.
24 MEMBER MARTIN: Thank you.
25 MR. PEABODY: All right, Aaron, next NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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slide. So were recommending Alternative 3 in the 2
reg. base, which will replace the current enrichment 3
limit 50,58, paragraph B(7), with the tech spec design 4
features limit. This requirement is also featured in 5
tech spec 4.3, the design feature section.
6 This will have the advantages of 7
maintaining existing sub-criticality margins at the 8
same probability and confidence levels. The 9
criticality safety impacts will continue to be 10 addressed during the fuel transition license amendment 11 request process, and it will be looked at in advance 12 of the application by the NRC staff.
13 It will allow us to consider low-enriched 14 uranium up to 20 percent weight. We are doing a 15 criticality research study with Oak Ridge National 16 Laboratory just to verify that the increased 17 enrichment will be capable of being addressed with 18 existing technologies, particularly integral fuel 19 burner absorbers coatings and gadolinium rods.
20 Were also, I think its important to note 21 that this will preserve 50.68 compliance for all of 22 the existing fleet without the fact that because 23 essentially when they increase enrichment beyond 5%,
24 that becomes a voluntary initiative on their part.
25 But theyre still able to continue applying at any NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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current existing enrichment levels that theyre 2
approved for without additional licensing actions.
3 Thats all I had on --
4 (Simultaneous speaking) 5 MEMBER MARTIN: Im going to hog the floor 6
on this. Just a simple question. So basically, 50.68 7
is being proposed without a limit, with this statement 8
here, replacing the current enrichment limits with a 9
tech spec, design features. So thatd be, again, on 10 the applicant.
11 MR. PEABODY: Yes, it would be --
12 MEMBER MARTIN: Is there any need for, 13 like from a proliferation perspective? Is there going 14 to be a guardrail at some higher level? I mean, I have 15 no experience in that, but.
16 MR. PEABODY: So I mean --
17 VICE CHAIR KIRCHNER: Precisely. Are you 18 going to put 20% in?
19 MR. PEABODY: The answer to that would be 20 no. We would specify the limit in the tech spec.
21 However, that limit would be less than 20% because 22 theres a prohibition on going above 20%. I believe 23 its in 50.64. Yeah.
24 And again, too, like theres still going 25 to be a limit thats explicitly specified in the tech NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
25 1
specs that that particular facility will not be able 2
to go above without coming back with, again, a new 3
criticality analysis that shows in advance that its 4
safe to go to a higher enrichment.
5 Ill also provide a quick comment on 6
Walts earlier question on the non-LWR. As part of 7
the reg basis that we looked at, I know for my section 8
and I believe for most of the other presenters, we did 9
look at the 50 -- Im sorry, the Part 53 separate 10 rulemaking, which is in draft right now. I believe 11 its in the proposed rulemaking phases out, so its 12 still a draft guidance.
13 But what were proposing here is 14 consistent with what theyre proposing there for 15 nuclear criticality analysis.
16 VICE CHAIR KIRCHNER: The reason I brought 17 it up is because the advanced reactors that come in 18 are going to go through 50 and 52. Theyre not going 19
-- 53 is not going to be ready. And they may not 20 choose the 53 option, even if it were ready.
21 So when youre doing this, that was the 22 purpose of my question. So that you dont, soon as 23 you get one of those advanced reactors, you dont have 24 to get into the exemption space again. Because 25 several of them are going to look at going up to 20%.
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Or just below.
2 MR. PEABODY: Yeah, thats true. And 3
again, like the draft rulemaking for Part 53, which I 4
acknowledge it may not be ready, but thats similarly 5
-- its basically its similar to 50.68 in that it 6
utilizes k-effective acceptance criteria, not active 7
criticality monitoring like 70.24.
8 VICE CHAIR KIRCHNER: Good, thank you.
9 MEMBER MARCH-LEUBA: This is Jose. Just 10 a clarification. Im looking at 10 CFR 50.64. And it 11 seems to apply only to non-power reactors. You guys 12 can check that out, make sure that the 20% -- thats 13 what I'm reading is (audio interference) for non-power 14 reactors.
15 MR. BENAVIDES: Okay, but this is 50.68, 16 so.
17 MR. PEABODY: Yeah, so --
18 MR. BENAVIDES: Sorry, sorry, part of --
19 Charlie.
20 MR. PEABODY: Thats where they delineate 21 the high-enriched uranium and low-enriched uranium 22 threshold. I think theres also a -- I think they 23 also define that in Part 2 of the definitions section.
24 But again, I know -- I dont believe that any of the 25 power reactors were applying enrichments nearly that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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high when that was written.
2 But typically 20% is considered high-3 enriched uranium. We generally try to stay away from 4
that in Part 50 or Part 52 applications as well.
5 MEMBER MARCH-LEUBA: My question is -- my 6
comment is please review it, because it seems a 7
naughty thought anybody would be crazy enough to do 8
22% enriched uranium on a power reactor. At least it 9
may not be actually in anyone.
10 MR. PEABODY: Yeah, I mean, you would have 11 to get the, I believe like the specific approval that 12 that requires. But Im not ready to talk about 50.64 13 today.
14 Im not hearing any other questions, so I 15 think Ill turn it over to the next presenter, which 16 I think is back to you, Phil.
17 MR. BENAVIDES: Yeah, thats correct.
18 Aaron, next, thank you.
19 Once again, Phil Benavides. As mentioned 20 earlier, Don Palmrose is not available, so Im going 21 to present a few prepared remarks on his behalf.
22 Slide 14, please.
23 (Audio interference) fuel cycle and 24 transportation of fuel and waste are connected actions 25 of the operation, nuclear power plants, under the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
28 1
National Environmental Policy Act, or NEPA. Staff has 2
previously performed generic analyses dating back to 3
the 1970s to evaluate the environmental effects of the 4
uranium fuel cycle in transportation of fuel and 5
waste.
6 These evaluations are documented in WASH-7 1248 for the uranium fuel cycle, and WASH-1238 for 8
transportation of fuel and waste, with the other 9
supporting documents. This original analysis was for 10 enrichment levels up to 4 weight percent U-235.
11 The uranium fuel cycle analysis was 12 codified in the 10 CFR 51.51 as Table S-3 for the 13 transportation of fuel and waste. The environmental 14 effects were codified in the 10 CFR 51.52 as Table S-15 4.
16 Subsequent staff evaluations expanded 17 Tables S-3 and S-4 for up to 5 weight percent U-235.
18 Of note for Table S-4, there are other conditions that 19 must also be met, else a full description and detailed 20 analysis of the transportation impacts would need to 21 be performed as part of the licensing action.
22 The staff has performed additional 23 analyses to extend the enrichment levels above 5 24 weight percent. This has been done in two documents.
25 The first is a study to support accident-tolerate fuel NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
29 1
deployment published in NUREG-2266, which the public 2
comment period closed recently on October 31.
3 Additionally, the advanced nuclear reactor 4
generic environmental impact statement that is before 5
the Commission for approval also addresses the uranium 6
fuel cycle for up to 20 weight percent U-235.
7 Until these documents have been finalized, 8
the current practice for addressing these 9
environmental impacts continues to be as, which is 10 shown in the last two sub-bullets, where the uranium 11 fuel cycle evaluations would be on a case-by-case 12 basis, as has been done in prior new reactor 13 applications.
14 And a full description and detailed 15 analysis would need to be performed for transportation 16 and fuel and waste. Next slide, please.
17 The staff considered three alternatives 18 for both the 51.51 and Table S-3 and 51.52 and Table 19 S-4. The first is the current situation, as mentioned 20 in the previous
- slide, which addressed the 21 environmental effects on a case-by-case basis.
22 Alternative 2
is the recommended 23 alternative, which would incorporate the updated 24 evaluations in NUREG-2256 and the advanced reactor 25 GEIS into the regulation by this rulemaking to extend NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
30 1
Table S-3 and S-4 to the highest enrichment levels 2
these analyses can support.
3 The third alternative would be not codify 4
the updated evaluations but reference them for the 5
environmental finding in individual license actions.
6 Next slide.
7 Thats the end of that presentation. If 8
theres any questions, you know, unfortunately, Dons 9
not here to provide additional insights, but we can 10 take note and get back to you.
11 MEMBER HALNON: Yeah, this is Greg. Just 12 when you said the highest enrichment that it could 13 take. From the analysis, Im assuming thats still 14 going to be 20 percent is going to be the top amount.
15 I mean --
16 MR. BENAVIDES: Correct, correct.
17 MEMBER HALNON: Okay, youre staying low.
18 MR. BENAVIDES: Its still low. I 19 believe, you know, I would have to look into it. But 20 I think maybe when they started, they may have been 21 looking at maybe the current fleet and where they were 22 going. Which maybe not the --
23 MEMBER HALNON: Okay.
24 MR. BENAVIDES: So.
25 With that, I guess well go on to the next NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
31 1
topic, which will be Jason Piotter.
2 MR. PIOTTER: Thank you, Phil. My name is 3
Jason Piotter, I am a Senior Mechanical Engineer in 4
the Division of Fuel Management. I am the lead for a 5
ATF and advanced fuels in the Office of Nuclear 6
Materials Safety and Safeguards.
7 Today Im going to briefly discuss our 8
consideration of the fissile material package 9
requirements contained in 10 CFR 71.55. The 10 regulations in 10 CFR Part 71 for package and 11 transportation of radioactive material in general do 12 not limit the enrichment level of the fissile 13 material.
14 In one instance, 71.55(g), specific to UF6 15 packages, a provision is made that allows for an 16 exception to the requirement to consider water and 17 leakage, provided that the UF6 content is not enriched 18 to greater than 5 weight percent U-235. And theyve 19 already advanced the slide for me, so thank you.
20 Absent utilizing the provisions in 10 CFR 21 71.55(g), applicants for a certificate of compliance 22 have the option of evaluating these fissile material 23 transportation packages, including UF6 packages, in a 24 variety of ways.
25 One, they could use 71.55(b), including NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
32 1
consideration of water in-leakage, which for higher 2
enrichments may require changes to current package 3
designs or perhaps require new package designs to 4
accommodate those enrichments.
5 An applicant could seek an exemption to 6
71.55(b) and the water in-leakage requirements. Or an 7
applicant could seek an exception to the water in-8 leakage requirements of 71.55(b) using the provisions 9
in 71.55(c). Next slide, please.
10 Based on its evaluation, the staff 11 identified three alternative actions that the NRC 12 could take. The first would be no rulemaking and 13 utilize the existing certificate of compliance options 14 I just mentioned.
15 The second option would be rulemaking to 16 increase the enrichment limit up to 20 weight percent 17 U-235. And the third option would be rulemaking to 18 remove the enrichment limit altogether on this 19 exception. Next slide, please.
20 The staff recommendation at this time is 21
-- go ahead? Was there a question? Okay. The staff 22 recommendation at this time is to take no action.
23 And thats primarily due to the fact that 24 to date, the industry plans communicated to the NRC 25 have not indicated that there would be enough requests NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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for package approvals for transporting UF6 enriched up 2
to 20 weight percent to conclude that rulemaking would 3
be the most efficient or effective process to support 4
package approvals.
5 And Ill note that all alternatives at 6
this point are cost-neutral in terms of 7
implementation, but they vary based on where the 8
burden of that cost would be born.
9 In light of the current recommendation of 10 no rulemaking, the staff is seeking additional 11 feedback, however, from stakeholders to determine if 12 theres any additional information that can be shared 13 to augment comments made by the public in June of 2022 14 regarding the need for rulemaking, which did not 15 indicate a strong demand signal from industry for 16 rulemaking for these UF6 packages. Next slide, 17 please.
18 MEMBER HALNON: Jason, this is Greg 19 Halnon.
20 MR. PIOTTER: Yes, sir.
21 MEMBER HALNON: Did you factor in this 22 decision the aspect of regulatory certainty relative 23 to this being the best alternative?
24 MR. PIOTTER: Yes, we did. And part of 25 that consideration is also going to factor in the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
34 1
responses that we get from the FRN question. And so 2
we still have an opportunity after the public comment 3
period to discuss that internally and sort of take a 4
final action or make a final decision on that point.
5 But we wanted to also see if there was an 6
additional demand signal coming from industry. So it 7
is still on the table at this point, but again, if 8
youre looking at the total demand signal that we 9
expect to see and the fact that weve been able to 10 issue CoCs for a UF6 package thats certified up to 20 11 weight percent.
12 Its already been demonstrated that the 13 existing regulations are effective for being able to 14 issue certificates of compliance.
15 MEMBER HALNON: Okay. Is there guidance 16 out there for that, or are folks just using the 17 precedent set by that approval you just mentioned?
18 MR. PIOTTER: Theres not specific 19 guidance at this point, I think primarily because the 20 applicant in that case used the existing regulation in 21 71.55(b). So they considered water in-leakage for 22 that particular package and had special design 23 features to account for the fact that they had higher 24 enrichment.
25 So we did not anticipate doing additional NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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guidance at this point for that because at the time, 2
it was relatively straightforward with respect to the 3
regulatory approach that they took.
4 MEMBER HALNON: Okay, so that would be an 5
option if the demand goes up for such approvals, but 6
at this point no need.
7 MR. PIOTTER: Thats correct.
8 MEMBER HALNON: Thank you.
9 MR. PIOTTER: And -- go ahead.
10 MEMBER MARTIN: Oh, I was going to change 11
-- if you wanted to complete a thought for Member 12 Halnons question, go ahead and finish it. Okay.
13 So I understand the logic behind what you 14
-- your no-action recommendation. Kind of in the 15 spirit of generically addressing things, it seems like 16 it stands out, you know, oddly with everything else 17 youre trying to do.
18 Here, the door is open. Why not just walk 19 through it, you know, and spend the effort to just be 20 consistent across the board with the overall effort.
21 If there was any question on guardrails, 22 and again, Im not, you know, familiar enough with 10 23 CFR 71, I mean, could a k-effective limit or something 24 like that, like its elsewhere, like in 68, could that 25 kind of cover you for any concern?
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Basically my question is why not just make 2
it clean with the rest of the changes that are in --
3 that are all in the table maybe?
4 MEMBER MARTIN: No, and I appreciate that 5
comment. And what I will say is we had received 6
unofficial comments to that effect. That was 7
essentially the one comment that we did receive that 8
since we are going ahead with this rulemaking, why not 9
just consider it here as well.
10 I think the difference here is that we 11 have a very robust set of options within this 12 particular regulation that offers industry a variety 13 of ways to meet the regulation without necessarily 14 having to focus on this very specific one for UF6 15 packages. Because keep in mind, obviously the 16 71.55(b) applies to all fissile material packages, not 17 just UF6.
18 So in that instance, because its narrowly 19 focused and because there are additional options 20 available, the assessment at the time was is that in 21 this particular
- case, because of the other 22 considerations with respect to cost and with respect 23 to demand signal, it wouldnt be necessarily efficient 24 or effective to move forward.
25 But certainly we have received that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
37 1
comment and it has been taken into consideration in 2
our deliberations.
3 MEMBER MARTIN: Thanks.
4 MR. PIOTTER: I would like to add just 5
real quickly to two of the other questions that were 6
asked earlier with respect, the first one with respect 7
to experiments.
8 I will note that at least on the front end 9
of the fuel cycle and the back end of the fuel, cycle, 10 there is an active effort underway currently to do 11 additional critical experiments, as well as to do 12 benchmarking up to that 20 weight percent mark. And 13 again, thats obviously to focus on the fact that we 14 do not have that data available for those enrichment 15 ranges.
16 The second item I just wanted to comment 17 very quickly is with respect to are we considering 18 advanced reactor fuels. And what I will say for with 19 respect to NMSS, you know, we see those throughout the 20 presentations that 20 weight percent is noted several 21 times in the presentations.
22 I think when we got the SRM that came back 23 down, that mention that we need to take into account 24 the HALEU range, that automatically put us in that 25 category of considering both ATF fuel and advanced NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
38 1
reactor fuels in our deliberations. At least thats 2
very much true for the NMSS evaluation.
3 MEMBER MARTIN: I appreciate that comment.
4 MR. PIOTTER: And with that, Phil, I did 5
not have anything else, so we could go to the next 6
presentation if there are no further questions.
7 MR. BENAVIDES: Okay, the next presenter 8
is Elijah Dickson presenting on control room design 9
criteria.
10 MR. DICKSON: Thank you very much. My 11 name is Elijah Dickson, Im a Senior Reliability Risk 12 Analyst in the Office of Nuclear Reactor Regulation, 13 Division of Risk Assessment, Radiation Protection 14 Consequence Branch. And Ive been leading the 15 ATF/source term work and coordinating work with the 16 Office of Research now for a number of years on this.
17 So I can jump into my presentation, but 18 before that, I can, based off my recollection of the 19 public meeting last week, talk a little bit about some 20 of the questions that we did have, if you like.
21 CHAIR REMPE: Please do.
22 MR. DICKSON: Okay, all right. So, and 23 theyre mostly clarifying questions. We have two 24 questions for folks to respond to in the reg bases.
25 The first one is in regards to how much information is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
39 1
being requested. And I believe that was from industry 2
in regards to the questions.
3 The first question was asking whether or 4
not -- well, lets start with the second question, 5
because that was the first question that was asked in 6
the public meeting. I think one of the owners had 7
asked a question in regards to instead of just having 8
one single value as a control room design criteria, we 9
are posing whether or not we should have a range of 10 them, right.
11 And should we develop some type of risk-12 informed metric to have for the control room design 13 criteria. The question was basically asking is that 14 in fact what youre looking for.
15 So instead of just having one value, wed 16 have a range of safe values tethered to some type of 17 risk measure. That was the first question, and thats 18 effectively our response, is yes, thats effectively 19 what were looking for.
20 And then the second -- sorry. Then the 21 first question was should the control room design 22 criteria, that numerical value, be based off of normal 23 operational exposure does limits of Part 20. Or 24 should it be based off of emergency protective type 25 dose recommendations? So that was the second -- that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
40 1
was the second question.
2 And they wanted to know just how much 3
information they needed to present to us in their 4
response to that question.
5 Any questions about that? No.
6 And then I can talk a little bit about 7
like the generic language as well thats discussed in 8
Appendix A of the reg bases in regards to what weve 9
been seeing as of late in license amendment space and 10 in topical report space. And it ties into how 11 licensees try to retain margin in these calculations 12 and trying to meet that control room design criteria 13 value.
14 And that weve been seeing
- with, 15 especially with the vendors in developing topical 16 reports, coming up with other types of methods and 17 methodologies to do the dose analyses.
18 And so to try to keep consistency with the 19 fleet, we felt that it would be appropriate to go, in 20 the consequence analysis, you know, realm, instead of 21 approving different topical reports and different 22 license amendments, to retain this margin in their 23 analyses that wed go and do a thorough reassessment, 24 I suppose, of the design criteria at this point.
25 Does that answer your question in regards NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
41 1
to like generically figuring, assessing this?
2 SPEAKER: I have a question.
3 MR. DICKSON: Yeah, okay, we can get into 4
it, okay. All right, so Ill go ahead and start the 5
formal part of the presentation. So the first part of 6
the presentation is a summary of the regulatory 7
issues.
8 General design criteria 19, the control 9
room of Appendix A of 10 CFR Part 50, and 10 CFR 10 50.67(b) item 3, provide specific dose-based criteria 11 in a 5 rem little effective dose equivalent for 12 demonstrating the acceptability of the control room 13 design.
14 The history of fuel utilization for the 15 current large light water reactor fleet has seen a 16 gradual progression towards higher fuel discharge 17 burnups and increased enrichments. In general, there 18 has been enough margin in the facilities design basis 19 to accommodate the criterion even for power upgrades 20 up to 120% of the originally licensed steady-state 21 thermal power levels.
22 Increased power levels, enrichment, and 23 subsequent fuel burnup have a multifaceted impact on 24 the licensees analysis of record computed design-25 basis accident radiological consequence analysis NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
42 1
results.
2 A rule of thumb is that an increase in 3
power level has a linear effect on these results, an 4
increase in enrichment necessary to reach the desired 5
burnup levels increases the number of fissions in the 6
reactor core in proportion increases these results.
7 The impact of higher burnup on 8
radiological consequences is not on the 9
radiological consequence results is non-linear for the 10 abundance of different radionuclides peak at different 11 burnup levels.
12 Therefore, depending on how the reactor 13 core is designed with an increased enrichments and 14 operated at higher burnup levels to reach longer cycle 15 times, the impact on these radiological consequence 16 analysis results computed to demonstrate compliance 17 with the control room design criteria would increase 18 and subsequently decrease the retained margin 19 maintained by licensees to provide operational 20 flexibility.
21 Now, the NRC recognizes the challenges 22 licensees face in retaining this margin for 23 operational flexibility purposes within their 24 licensing basis in the small amount of margin through 25 the control room design criteria itself.
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The NRC does not want to unnecessarily 2
penalize licensees in seeking increased enrichments 3
that may then result in margin reductions and thereby 4
require licensees to perform potentially extensive 5
analyses to demonstrate compliance without a
6 commensurate increase in safety. Slide 11.
7 MEMBER HALNON: This is Greg. The real 8
challenge at the licensee level is that demonstration 9
of compliance. If its in analysis space, thats not, 10 you know, its pretty straightforward from analysis.
11 Its when it gets into the physical testing of the 12 control room envelopes and --.
13 Is there from a tech spec perspective, I 14 mean, we all talk about theres so much leakage, in-15 leakage you can have into the control room envelope.
16 And Ive done those tests myself, and theyre one, not 17 repeatable. Two, you cross your fingers every time 18 you start to test and hope that you can get there.
19 But typically what weve done is just do 20 a complete physical examination of all the penetration 21 and whatnot. Are we staying in analysis space in this 22 rulemaking, or are we?
23 MR. DICKSON: Were staying in analysis 24 space.
25 MEMBER HALNON: Okay, so were not going NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
44 1
to require or ask for any other compliance 2
demonstration from a physical perspective?
3 MR. DICKSON: No.
4 MEMBER HALNON: Other than making sure 5
your design configuration is correct.
6 MR. DICKSON: Thats correct. Yeah.
7 MEMBER HALNON: Thanks.
8 MEMBER MARTIN: And that was my kind of 9
one question, just to clarify. So the slide or two 10 coming up, it makes a comment about some new research, 11 but its pretty much all analytical that you --
12 MR. DICKSON: Yeah, its all analytical.
13 MEMBER MARTIN: Okay.
14 MR.
DICKSON:
Those are in the 15 alternatives, I believe.
16 MEMBER MARTIN: All right.
17 MR. DICKSON: So lets go on to slide 24, 18 please. A little bit of background about the control 19 room design criteria. GDC-19 and subsequently 10 CFR 20 50.67, B2, item 3, is one of 64 general design 21 criteria provided in Appendix A of 10 CFR Part 50.
22 As stated in Appendix A, these general 23 design criteria establish minimum necessary design 24 fabrication construction testing and performance 25 requirements for structure systems and components that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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provide a reasonable assurance that the facility can 2
be operated without undue risk to the health and 3
safety of the public.
4 Although some design criteria may be 5
reflected in the technical specifications, the GDCs in 6
and of themselves are not operational limits. When 7
put into practice, nuclear steam supply system 8
engineers, architect engineers, utility engineers use 9
these criteria and other regulatory requirements in 10 establishing the design basis of the facility be 11 constructed.
12 In evaluating the adequacy of the design, 13 for instance for the control room habitability 14 envelope, designers evaluate the control room by 15 performing a series of deterministic design basis 16 accident analyses.
17 During its review of the license 18 application or the license amendment, the staff 19 reviewed a design in the applicants DBA analyses and 20 performed subsequent confirmatory calculations as 21 necessary and either accept or reject the application.
22 So with that, lets talk a little bit 23 about the objective of the control room design 24 criteria. The objective is to ensure that the design 25 of the control room and its habitability systems NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
46 1
provide for a habitable environment for operators to 2
remain in the control room and not evacuate during an 3
emergency.
4 Ideally, you can think of this environment 5
as short-sleeved environment comfortable for them to 6
perform their safety functions under both normal and 7
accident conditions.
8 A little bit of history behind the control 9
room design criteria. It was really developed in the 10 last 60s. Finalized in the GDCs in the early 70s, and 11 then subsequently amended in the 1990s when the NRC 12 finalized 10 CFR 50.67 for the alternative source 13 term.
14 The criterion did not foresee how 15 licensees currently operate their facilities and 16 manager their fuel, consider fuel enrichments above 5 17 weight percent uranium-235, or maintain coherence with 18 other regulations concerning the Commissions 19 comprehensive radiation protection framework.
20 A little bit more about the intent of the 21 control room design criteria. I have paraphrased from 22 the statements of consideration for 50.67 that the 23 control room design criteria does not imply that this 24 would be an acceptable exposure during emergency 25 conditions, or that the other radiation protection NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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standards of Part 20, including organ dose limits, may 2
not apply.
3 This criterion is provided to assess the 4
acceptability of the design provisions for protecting 5
the control room operators under postulated design 6
basis accident conditions. So Id like to go onto 7
slide 25.
8 MEMBER PETTI: A question.
9 MR. DICKSON: Yeah.
10 MEMBER PETTI: Part 20 does allow for 11 higher doses?
12 MR. DICKSON: Yes, it does, and Ill talk 13 about that. What Im going to try and do in this, in 14 I think in two slides, I added -- and I talk about the 15 different slides that I added to this from the 16 subcommittee meeting to try and like tie together this 17 web of regulations for you to fully give you a full 18 picture of how were looking at this.
19 And the slide deck that I have here is a 20 little different than whats there. So yes, 21 background. So in this work, effective radiological 22 risk communication is going to play a very important 23 role in this rulemaking effort to describe the NRCs 24 comprehensive radiation protection framework and how 25 it works together to protect occupational workers.
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Although the control room design criteria 2
are distinct from operational limits, the NRC 3
recognizes that the two concepts share some 4
similarities. Specifically, both the operational 5
occupational exposure limits of Part 20 and the 6
control room design criteria are numerically 7
equivalent and use the same units of rem TEDE.
8 Accordingly, the staff recognizes that 9
there could be some potential for confusion should the 10 NRC modify the control room design criteria to a 11 higher but still safe performance level. Changes 12 would not alter operational or emergency exposure 13 limits controlled under Part 20, and subsequently 14 50.47, which are the emergency plans. Slide 26, 15 please.
16 This is a new slide from -- that was 17 developed since the subcommittee meeting. The 18 standards for radiation protection are found in 10 CFR 19 Part
- 20.
They are based in part on the 20 recommendations on the International Commission of 21 Radiological Protection.
22 In 10 CFR Part 20, the NRC applies these 23 standards to all exposure situations, both normal and 24 emergency conditions, but also provides an explicit 25 exemption in cases in which compliance would limit the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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actions that may be necessary to provide health and 2
safety.
3 To provide reasonable assurance that 4
adequate protective measures can and would be taken in 5
a radiological emergency, the NRC has established the 6
emergency planning regulations in Appendix E of 10 CFT 7
Part 50, as well as the emergency plans of 10 CFR 8
50.47. Its these emergency plans that provide 9
additional regulatory provisions to bear on the 10 control of occupational exposures during emergencies.
11 As paraphrased from 10 CFR 50.47(b)(11),
12 the following is provided, Where there is the means of 13 controlling radiological exposures should -- shall 14 include exposure guidelines consistent with the EPAs 15 Emergency Worker and Lifesaving Activity Protective 16 Action Guidelines, or PAGs. These guidelines for 17 actions to protect valued property is 10 rem, where 18 lower dose is not practical.
19 The guidelines for actions for saving life 20 or protecting large populations is 25 rem. These 21 guidelines are endorsed, as I had mentioned, in 10 CFR 22 50.57, and is consistent the position in 20.1001(b).
23 MEMBER BALLINGER: This is Ron Ballinger.
24 I have had drilled into me over the last 30 years the 25 rule 5n-18 and 25.
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MR. DICKSON: Thats right. Thats the old 2
3 MEMBER BALLINGER: I thought it would be 4
very easy to find the source of that. Youve got the 5
25 in here, but for the life of me I cant, other than 6
in a Navy manual, I cant find where the heck 5n-18 7
came from.
8 MR. DICKSON: That might be under the old 9
ICRP 2.
10 MEMBER BALLINGER: Okay, Ive got a bunch 11 of ICRP documents.
12 MR. DICKSON: Thats going back to like 13 the 1950s, and --
14 MEMBER BALLINGER: Well, thats probably 15 right, since thats when I learned it.
16 MR. DICKSON: Yeah. So we went through, 17 you know, it wasnt great trouble, but -- we went 18 through great trouble to understand like the genesis 19 of these values and how they got in here, right. And 20 for the control room design criteria, the rationale 21 when they were doing that work in the early or late 22 60s, they codified the GDCs, it is kind of lost to 23 time.
24 There is a bit of discussion in Appendix 25 A on that topic. We pulled documents internally in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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microfiche, ADAMS, legacy ADAMS. We were able to find 2
some internal documentation as to why they selected 3
Part 20 normal dose limits as the design criteria back 4
then.
5 And the best that we could find was that 6
there was only like a document changed based off of 7
industry comments on those old GDCs that they said, 8
you know, they wanted to pull out the design criteria 9
itself. But when the final GDCs were put into place 10 in GDC-19, the original GDC had a reference to Part 11 20, is what it had, is GDC-11 was the original GDCs 12 that were proposed.
13 Then in GDC-19, the finalized one, they 14 removed the reference to Part 20 occupational exposure 15 limits and retained the numerical values. And then 16 when they developed 50.67, we kept with that, we kept 17 with that thinking, utilizing the numerical values 18 that were in Part 20 as the design criteria for these 19 emergency-type conditions.
20 So I tried my best to do the literature 21 review in that area, and it wasnt terribly 22 satisfying. But you know, a lot of the stuff was done 23 back in the 50s.
24 MEMBER BALLINGER: Thank you.
25 CHAIR REMPE: We have a question from a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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consultant, Stephen Schultz.
2 Steve, do you want to unmute yourself and 3
ask it?
4 MR. SCHULTZ: Yes, I just wanted a 5
clarification first. The last bullet that you have 6
here is that guidelines for action is ten rem, and my 7
question is simply the guidelines you're referring to 8
here is 10 CFR Part 20. Is that where that is coming 9
from?
10 MR. DICKSON: No, that's coming from the 11 EPA's PAG guidelines.
12 MR. SCHULTZ: Okay, and just a comment as 13 well. When I went through the appendix associated 14 with the regulatory rulemaking basis and so forth, and 15 in the basis itself, I really didn't find a detailed 16 description of what this background is and where 17 you're going with it.
18 What I did find in the references was the 19 NRC's report in June this year on increased enrichment 20 rulemaking -- on the control room design criteria and 21 radiological health effects. That was as a reference, 22 and as I looked at that, I found information that 23 really supports this approach, this evaluation and the 24 presentation you're making today. I think more 25 information ought to go in the main document as you go NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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forward with your recommendations.
2 MR. DICKSON: Understood, and we can do 3
that. That was a research request that we made to the 4
Office of Research to assess the control room design 5
criteria in the context of, I think, current health 6
physics, radiation protection standards, understand 7
what's out there, understand what the research is, 8
understand what's being recommended by bodies such as 9
the ICRP, the NCRP, the EPA, and give us a jumpstart 10 into how we're going about moving forward in this 11 area, and we can pull some of that information into 12 the regulatory basis too.
13 MR. SCHULTZ: It's a very well-prepared 14 report that provides elements of justification of why 15 this approach may be suitable going forward.
16 MR. DICKSON: Right.
17 MR. SCHULTZ: Thank you.
18 MR. DICKSON: Yeah, thank you. Well, 19 thank you for that.
20 MEMBER ROBERTS: Elijah, if I can -- this 21 is Tom Roberts. If I can repeat back what I think you 22 just said on the last two slides, and then I'll have 23 a question at the end of it?
24 MR. DICKSON: Yes.
25 MEMBER ROBERTS: I want to make sure I got NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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it right, that the previous slide talked about a 2
figure of merit, that the five rem, ten rem, whatever 3
the requirement is really has no physical meaning.
4 It's a figure of merit. It's as this is a 5
prescription that's been agreed upon in the past. If 6
you calculate that your control room dose is below 7
this number, you're good.
8 And what good means is not entirely clear 9
to me, but you're good, which leads to the next part 10 of this, which is once you get into the reactor 11 accident space, you have emergency guidelines imposed, 12 which is you take whatever you, basically, to some 13 degree, whatever you need to take given certain 14 guardrails that are put into place, or you ask for 15 volunteers when you get beyond those guardrails, but 16 if you have to take actions to save the reactor or, 17 you know, help the public, or whatever the objective 18 is, you're going to find a way to take it. Do I have 19 that right so far?
20 MR. DICKSON: That's right. That's right.
21 MEMBER ROBERTS: So, what I'm still not 22 completely seeing is a connection between those two, 23 because we talked yesterday in the level three PRA 24 discussion about how they've started to do a level two 25 HRA, and part of the level two HRA is an evaluation of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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control room doses during accident scenarios.
2 And we didn't get a whole lot of detail of 3
what came out of the studies, but it's a relatively 4
new technique they're using to try to gain a better 5
understanding of the risk associated with, you know, 6
getting into the level two, level three reactor damage 7
state. And that seems to have a connection to what 8
you're doing here and I'm still not completely seeing 9
that connection --
10 MR. DICKSON: Okay.
11 MEMBER ROBERTS: -- that if you increase 12 the allowable figure of merit for, you know, your 13 control room dose, and presumably the TSB is part of 14 this, then you're also increasing what that dose is 15 going to be in the emergency situation, and then it 16 becomes more and more difficult for the operators to 17 take those actions, and it seems that you would 18 understand that, and maybe that's part of the risk 19 information you were talking about with the public 20 meetings you have --
21 MR. DICKSON: Yeah.
22 MEMBER ROBERTS: -- earlier, but it seems 23 like that whole story ought to be better understood.
24 MR. DICKSON: It's a complicated story, 25 and what I failed to do during the subcommittee NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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meeting, you know, I really stressed on, and I did in 2
this last paragraph or last slide too, about how the 3
framework of radiation protection works and how it is 4
cohesive, but what I did not provide was the 5
guidelines and procedures that operators are trained 6
to during accident conditions.
7 So, that's like when they have to exercise 8
the EOPs, the emergency operating procedures, when 9
they go in and they have to start exercising their 10 SAMGs, and the flex, as well as the extensive EDMGs, 11 extensive mitigation via damage guidelines that were 12 developed after post-9/11, and so I failed in that 13 area. And I did develop a slide to help talk about 14 that.
15 So, having discussions in regards to how 16 Part 20 controls occupational exposures during an 17 actual event was done well, but we need to strengthen 18 discussions in regards to what operators are actually 19 doing during an event, and I do have a slide in here 20 that kind of talks about that. At one point, it was 21 slide 47, and if we need to, we can jump to that in 22 the questions' section.
23 VICE CHAIR KIRCHNER: Can you go back one 24 slide? Because your lead in to this -- or it might be 25 another one further back then. Yeah, this is it, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
57 1
yeah. What I noticed is I would almost bold the word 2
emergency, the third line. I mean, the way I'm 3
thinking about it is that an emergency is when you 4
actually have the accident.
5 MR. DICKSON: Yeah.
6 VICE CHAIR KIRCHNER: That's not normal 7
operation. Whether it's a DBA or a beyond DBA, it 8
doesn't matter, and for normal operation, the figure 9
of merit should be way below five rem, I mean, because 10 that wouldn't meet ALARA in my mind.
11 MEMBER HALNON: This is exactly why I 12 asked the question earlier about staying in analytical 13 space versus physical. Every emergency plan I've been 14 associated with would not allow somebody to get 25 rem 15 in a control room. You start developing shifts in 16 dose --
17 MR. DICKSON: Right.
18 MEMBER HALNON: -- goals as soon as you 19 get out of the area of trying to address the exact 20 accident. So, these are analytical figures of merit, 21 but it's not reality from the standpoint of what 22 physically is going on in running your procedures, and 23 developing shift coverages, and that sort of thing.
24 So, it gives you a design criteria. You 25 meet the design criteria, but your emergency plans and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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your actual physical aspects limit doses far below 2
these types of things. So, you can't sit there and 3
think oh, I'm going to let my operator get 25 rem.
4 That's not going to happen.
5 MEMBER ROBERTS: Right, where I think 6
analysis and reality meet is that if you design, you 7
know, have early systems, it will allow double the 8
dose, and you're going to double the challenge to the 9
operators who have to go stick to those procedures.
10 MEMBER HALNON:
You'll double the 11 challenge of getting operators --
12 MEMBER ROBERTS: Right, it might be --
13 (Simultaneous speaking.)
14 MEMBER HALNON: -- to minimize their dose.
15 You might have to have three shifts instead of two.
16 MEMBER ROBERTS: Right.
17 MEMBER HALNON: You know, but you're not 18 going to continue to dose out your operators --
19 MEMBER ROBERTS: Right.
20 MEMBER HALNON: -- because you need them.
21 MEMBER ROBERTS: And you're also not going 22 to give up.
23 MEMBER HALNON: Right.
24 MEMBER ROBERTS: So, it's --
25 MEMBER HALNON: So, there's other goals NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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going on, including ALARA, that --
2 MEMBER ROBERTS: Right, the first time I 3
asked is trying to understand what challenge the, you 4
know, going to a higher control room deterministic 5
figure of merit, you know, dose level, would impose in 6
emergency plan space, emergency preparation space.
7 And there is a footnote in the appendix that says that 8
there is no risk information to be gained, and it 9
seemed like from yesterday's meeting, there is risk 10 information to be gained.
11 MR. DICKSON: Yes, and --
12 MEMBER ROBERTS: Maybe that could be 13 beefed up in the report.
14 MR. DICKSON: Yeah, and again, the slide 15 that I provide at the very end of this talks a little 16 bit about that. I won't be as sharp presenting this 17 slide. I just developed it two days ago in thinking 18 about how I could talk about this.
19 You know, I'd like to add that the 20 calculations that are done to demonstrate compliance, 21 they don't really consider operator actions. You 22 know, they assume a full core melt with that source 23 term, but then design, you know, the leak rates for 24 containment and the leak rates, and assess the leak 25 rates out of valves and things of that nature.
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And the individual is a
reference 2
individual. It's just a person standing in that 3
control room during a certain amount of time. We also 4
don't model the administration of prophylactics, 5
right. So, KI is a very important prophylactic that 6
any radiation protection manager would probably be 7
administering to their operators and their staff to 8
protect against thyroid dose. Those types of things 9
are not modeled in these calculations.
10 And you think of it as well as this is 11 kind of like a defense in depth or margin to safety 12 between the current five rem and that upper bound EPA 13 25 rem value, right. So, right now, we have it at 14 five, the occupational exposure limit, or at least 15 referenced as it, and then you have this upper bound 16 of 25 rem, so we're trying to come up with something 17 in between. Okay, with that, I'll --
18 MR. SCHULTZ: This is Steve Schultz.
19 MR. DICKSON: Yeah.
20 MR. SCHULTZ: Just a reminder that with 21 regard to what we're generally speaking about here is 22 the control room limitations and design limitations 23 associated with the design basis accidents --
24 MR. DICKSON: Yeah.
25 MR. SCHULTZ: -- versus severe accidents.
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MR. DICKSON: Right.
2 MR. SCHULTZ: And so, the analysis we're 3
talking about that is done in the design process 4
associated with core reloads and so forth is the 5
evaluation for design basis accidents versus severe 6
accidents.
7 MR. DICKSON: Thank you. With that, I'll 8
go onto the next slide, slide 25, 27.
9 MEMBER ROBERTS: Just following up on what 10 Steve just said, it's not really even a design basis 11 accident, right? I think it truly is a figure of 12 merit because the scenario is not a consistent 13 scenario.
14 MR. DICKSON: Well --
15 MEMBER ROBERTS: There is probably no real 16 scenario that would lead to the five rem you calculate 17 in the control room.
18 MR.
DICKSON:
They are stylized 19 calculations, and the one that really matters is the 20 MHA LOCA source term where we use the MELCOR 21 calculations and come up with a full core melt source 22 term, and we use that to establish siting criteria as 23 well as for just control room design criteria as well.
24 MEMBER ROBERTS: Right, so Steve, tell me 25 if I've got this wrong, but I think the real key is NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
62 1
that there is this transition from analytical space to 2
operational space, as Greg well pointed out, that 3
there's a figure of merit that said this is good 4
enough, but it's kind of hard to put any physical 5
meaning on it.
6 If you don't meet good enough, then it's 7
a little worse than good enough, and I don't think 8
we're going to have a good insight on where we've 9
crossed that cliff. There probably is no cliff 10 because at some point it becomes much, much harder to 11 manage the accident, and again, that's where the risk 12 information may come in --
13 MR. DICKSON: Understood.
14 MEMBER ROBERTS: -- useful to understand 15 what does it really mean, because I don't think we 16 know right now what it really means other than for 50 17 years, we've used it as a guideline.
18 MR. DICKSON: Okay, so now I'll talk 19 about, if we're ready to move on, I'll talk about the 20 alternatives. The staff considered three alternatives 21 in this area. The first alternative is to take no 22 action.
23 We would maintain the current regulatory 24 framework. We would continue to revise existing 25 guidance with updated source terms when data become NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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available, as well as update transport models on an ad 2
hoc basis as research and resources become available.
3 We would plan to issue this work in Reg Guide 1.183, 4
Rev 2, in fiscal year 2025. Next slide, please?
5 Alternative two is to pursue rulemaking to 6
amend the control room design criteria and update the 7
current regulatory guidance accordingly with revised 8
assumptions and models, and continue to maintain 9
appropriate and prudent safety margin. The staff has 10 already assessed and identified a range of acceptable 11 values based on sound regulatory and scientific 12 recommendations.
13 We would be initiating new research and 14 analyses for the development of mechanistic transport 15 models and re-baseline several other important 16 operational and human health assumptions. We would 17 plan to issue this work in Rev 2 of Reg Guide 1.183 in 18 support of the control room, the amended control room 19 design criteria.
20 Alternative three, you can think of this 21 as our most research intensive alternative where we 22 would not be pursuing any rulemaking, but we would be 23 updating the current regulatory guidance with revised 24 assumptions and models, and continue to maintain 25 appropriate and prudent safety margin.
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We would be, like in alternative two, 2
initiating new research and analyses for the 3
development of mechanistic transport models, and re-4 baseline several other operational and human health 5
assumptions, and assess other mathematical methods, 6
computational, and statistical approaches to reduce 7
the unnecessary conservatisms and provide greater 8
flexibility. We would plan to commence this work on 9
Reg Guide 1.183, Rev 3 based on this new research 10 analyses soon after Reg Guide 1.183, Rev 2 has been 11 issued. Onto the next slide, please?
12 Our recommended option is alternative two, 13 an amended control room design criteria and revision 14 to the applicable regulatory guidance considering risk 15 information would be the most cost beneficial, 16 straightforward, durable, and efficient path for 17 licensing increased enrichments up to 20 percent of 18 radium-235.
19 The beneficial impacts on other 20 regulations such as 50.59 and Part 20 would also be 21 realized. It would be flexible enough to consider 22 multiple approaches, and amending the regulation would 23 provide an option for a generic resolution of these 24 issues. We would be inviting stakeholder input and 25 participation in this decision affecting this NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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regulatory area rather than on a case by case basis 2
that would result in the current regulatory framework.
3 Staff would be able to utilize ample 4
operating experience, scientific data, technical 5
information, and numerous recommendations from 6
national and international organizations responsible 7
for radiation protection standards and regulatory 8
precedents that supports the reevaluation of the 9
control room design criteria.
10 In general, there is a range of regulatory 11 base and stakeholder base recommendations for 12 radiation exposures to workers under normal and 13 emergency conditions, and these range from ten rem to 14 25 rem or 50 rad whole-body.
15 As such, the control room design criteria 16 intended to assess the acceptability of a given 17 control room design is on the lower side of this range 18 of recommended values for emergency response planning 19 purposes and protect against actual incurred radiation 20 exposures.
21 And that's it with my presentation today.
22 If we had additional questions, or I could go down to 23 one of the back-up slides that talks about more of the 24 like guidance and procedures that are in place that 25 operators are trained to, to respond to varying NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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degrees of accident conditions.
2 MEMBER HALNON: Elijah, from a process 3
perspective, Rev 2 says fiscal year 25 or --
4 MR. DICKSON: Yeah.
5 MEMBER HALNON: -- a month into fiscal 6
year 24. It seems like a lot of work to get done and 7
get approvals, and public comments, and everything 8
else done.
9 MR. DICKSON: It is.
10 MEMBER HALNON: Do you think it's doable?
11 I mean --
12 MR. DICKSON: I do. Rev 1 really laid the 13 groundwork in regards to how we want to approach 14 developing Rev 2. We are considering and looking at 15 the work that's already been done by Sandia in 16 performing additional analyses of their 2023 source 17 term report. We're looking at a lot of experience in 18 regards to the last 22 or 23 years of licensing 50.57 19 in the AST. There's -- we're ready to incorporate 20 this type of information.
21 MEMBER HALNON: When we reviewed Rev 1 of 22 1.183 --
23 MR. DICKSON: Right.
24 MEMBER HALNON:
we encouraged, 25 obviously, to not delay Rev 2 --
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MR. DICKSON: Yeah.
2 MEMBER HALNON: -- because it took so long 3
to get Rev 1 out. So, again, I think we would 4
encourage the same thing in this situation, obviously, 5
to make sure we meet that due date that we have for 6
the reg guide.
7 MR. DICKSON: Putting Rev 2 under the 8
umbrella of the increased enrichment rulemaking will 9
provide more resources --
10 MEMBER HALNON: Okay.
11 MR. DICKSON: -- to help move that 12 forward.
13 MEMBER HALNON: Okay, I was thinking it 14 would bog it down, but I'm glad you're optimistic.
15 MR. DICKSON: Yeah.
16 VICE CHAIR KIRCHNER: Elijah, are you 17 thinking, not to put you on the spot, but are you 18 thinking -- you know, you provided an additional slide 19 this morning to your slide deck that kind of 20 summarizes perhaps, or that provides the basis -- have 21 you taken a stab at writing this down, what this would 22 look like?
23 MR. DICKSON: I have.
24 VICE CHAIR KIRCHNER: Yeah.
25 MR. DICKSON: So, it's slide 46.
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MEMBER PETTI: We only have 44 slides.
2 MR. DICKSON: Oh.
3 PARTICIPANT: I'm sorry, the backups.
4 PARTICIPANT: It's a new backup?
5 MEMBER PETTI: Oh, you got them, great.
6 MR. DICKSON: Oh, okay.
7 MEMBER BALLINGER: We need to have the 8
backup slides as part of the record.
9 MR. DICKSON: Okay, so here's the backup 10 slide, and this is a simplified framework for 11 emergency response procedures and guidelines that 12 operators, licensees follow in regards to responding 13 to a range of accidents. The phrases and the words in 14 here are generic.
15 It can be different between PWRs and BWRs, 16 you know, specific to specific licensees, but I 17 developed this following some of the work that we'd 18 done in updating the severe accident guidelines for 19 BWRs and the severe accident management guidelines for 20 PWRs post-Fukushima, so some of that is all kind of 21 revised.
22 So, here is my written thoughts so far is 23 that following the subcommittee meeting, I found 24 myself thinking about the proposed control room design 25 criteria in 10 CFR 50.67 as it relates to severe NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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accidents that are beyond the design basis for safety-2 related SSCs for operating reactors.
3 I found that I focused too much on the 4
framework of regulations of protecting against 5
ionizing radiation from Part 20 and Part 50.47, and I 6
didn't adequately cover the framework for how each 7
licensee addresses an integrated use of emergency 8
response procedures and guidelines in such a way that 9
they work together to implement the best available 10 strategy for preventing or mitigating fuel damage and 11 limiting radiological released in beyond design basis 12 accidents. It's clear to me now that we need to have 13 further discussions in this and maybe include this 14 type of information in the regulatory bases documents, 15 so I do want to state my apologies in this.
16 So, what I found is I developed this 17 illustration to show how the conservative nature of 18 our regulations and the integration with other 19 regulations, along with the traditional design basis 20 accident analyses with their included defense in depth 21 and additional safety margin, help address operators 22 in successfully responding to a spectrum of accident 23 conditions.
24 This figure illustrates the framework of 25 how each licensee addresses this integrated use of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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emergency response procedures and guidelines in such 2
a way that they work together to implement the best 3
available strategy for mitigating radiological 4
consequences or preventing fuel melt.
5 The left side of this slide presents the 6
various procedures and guidelines that have been 7
developed. They are stacked in order of severity from 8
the bottom to the top, normal operating procedures up 9
to severe accident management guidelines.
10 The right side of the figure presents how 11 these procedures are implemented during various plant 12 states. We give a little bit of a definition between 13 procedures and guidelines. Procedures are documents 14 written as sequential instructions to perform a 15 function or address plant conditions where operators 16 and plant staff are expected to follow prescribed 17 instructions in a step by step, verbatim manner.
18 Guidelines, on the other hand, are not 19 necessarily provided as prescribed sets of 20 instructions and may not be followed in a step by step 21 manner. Rather, they provide suggested strategies and 22 implementation methods that may be used to address 23 adverse conditions or events, typically those beyond 24 the design basis of the facility.
25 Now, there's been some discussions and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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questions in regards to the assessment of operator 2
performance under accident conditions. This does, it 3
does fall in a different regulatory area under 10 CFR 4
Part 55 for reactor license, you know, operator 5
- training, senior reactor operator
- training, 6
requalification programs.
7 That stuff is done, but in a different 8
regulatory area that's outside of assessing the design 9
of the control room itself, and these are done for, 10 you know, the alarm response procedures or AOPs.
11 These are done for the EOPs. And then subsequently, 12 there is also the severe accident management 13 guidelines too. So, that's what I have here. Any 14 questions on this?
15 MEMBER HALNON: Yeah, I would add one 16 aspect if you can consider it, and that's the 17 emergency action levels that drive the TSC.
19 MEMBER HALNON: Yes, I mean, that clearly, 20 in the accident management regime, plus maybe a little 21 bit to the left of that line, take hold, and you can 22 take credit for the TSC and EOF staffs under 50.47.
23 I know you tried to separate that out, but that -- it 24 is essential in developing the severe accident 25 management strategies --
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MR. DICKSON: Understood.
2 MEMBER HALNON: -- and even the, or most 3
of the EOPs. Many EOPs will get you into, if you got 4
into the EOP, you probably got at least an alert or --
5 MR. DICKSON: Right, okay, yes, thank you.
6 I'll take any more comments on this and --
7 MEMBER PETTI: I like that. I like his 8
comment. I think there's going to be very effective 9
communication --
10 MR. DICKSON: Okay.
11 MEMBER PETTI: -- to the side.
12 MEMBER BALLINGER: For a metallurgist, 13 this is very --
14 (Laughter.)
15 MR. DICKSON: Okay.
16 MEMBER HALNON: You don't hear that very 17 often from metallurgists.
18 MR. DICKSON: Got it. I'm working on it 19 now. There's -- you know, all of these different 20 procedures, and guidelines, and strategies have been 21 developed over a period of 60 years or so. They all 22 have different regulatory hooks to them or not.
23 They all have different regulatory 24 requirements in regards to the training, and getting 25 it all down in one document, you know, in a distilled NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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format is something that we're looking into now based 2
off of our conversations that we've had here at the 3
ACRS, so thank you.
4 MR. SCHULTZ: Elijah, this is Steve 5
Schultz. I think you're moving in the right direction 6
with providing some very -- this is a super 7
communication tool, and it's also a good structure 8
that can be used to move forward with the goals of 9
this portion of the rulemaking.
10 One more comment associated with the 11 document itself, there seems to be a concern about 12 moving forward with the control room design 13 requirement that is higher than five rem TEDE, and 14 would that be difficult in communication to the 15 organizations associated with the overall operational 16 dose limits of five rem, moving away from that?
17 I really think that that's not a concern, 18 and that given tools like this, you can communicate 19 very clearly that there is a reasonable, a real reason 20 for the difference, and you really go down two 21 pathways to establish both of those requirements, and 22 it should be very clear to both the public as well as 23 the operational staff as to why the criteria are 24 different.
25 MR. DICKSON: Understood. Yeah, effective NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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radiological risk communication is clearly going to 2
play a very important role in this rulemaking effort 3
and making sure people understand what it is that 4
we're trying to accomplish here, so we'll continue on 5
with that and keep working on sharpening our message, 6
looking into areas that need to be looked in further.
7 We'll keep doing that. Do you have any questions?
8 No? Okay, all right, thank you. With that --
9 MEMBER BALLINGER: I'm about to make a 10 suggestion, Madam Chairman, that we take a break.
11 CHAIR REMPE: Okay, I'll honor your 12 suggestion. It's about 10:00 here, so why don't we 13 come back at 10:15?
14 MEMBER BALLINGER: Thank you.
15 CHAIR REMPE: So, we'll recess.
16 (Whereupon, the above-entitled matter went 17 off the record at 9:59 a.m. and resumed at 10:15 a.m.)
18 CHAIR REMPE: Okay, it's 10:15 and we're 19 back in session, and I'll turn it back to you and then 20 you can pass it onto the staff.
21 MEMBER BALLINGER: Now, what did Bette 22 Davis say? Buckle up, it's going to be a bumpy ride.
23 Anyway --
24 CHAIR REMPE: That must have been before 25 my time when she said that.
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(Laughter.)
2 MEMBER BALLINGER: He remembers. Okay, 3
let's proceed.
4 (Laughter.)
5 MS. SMITH: This is Ashley Smith. Joe 6
Messina and I are co-leads for the fuel dispersal 7
portion of the meeting. I'm going to be going through 8
the first few slides and then I'll hand it off to Joe.
9 Next slide?
10 First, I'm going to discuss what FFRD is 11 and then I'll discuss its history. High burnup 12 experiments have shown that fuel can fragment during 13 a loss of coolant accident. Differences in pressure 14 across the cladding can lead to ballooning and burst 15 of the cladding. The fragmented fuel can relocate 16 into the balloon region. If burst occurs, the 17 fragments can disperse into the reactor coolant 18 system.
19 The first image here is of FFRD testing 20 that was done at Argonne National Lab. It shows fuel 21 fragmentation occurring. The second image is a 22 pictorial representation showing that once the fuel 23 fragments, the fragmented pieces relocated into other 24 areas of the fuel such as the balloon region. The 25 third image shows results from the LOCA test at the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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Studsvik test facility, and as you can see, the burst 2
openings can be large enough for the fuel to disperse 3
into the reactor coolant system. Next slide?
4 This slide has a timeline of the history 5
of FFRD. To start, the 50.46 acceptance criteria for 6
LOCAs were created in 1974 when FFRD were not known 7
phenomena. In 1980, FFRD was discovered during 8
experiments at several test facilities, indicating 9
that irradiated fuel could fragment into small pieces 10 during a LOCA and may relocate axially, settling into 11 the balloon regions.
12 In 1984, NRC puts FFRD into the generic 13 issue program as GI-92, but later concluded that known 14 conservatisms would offset increased heat generation 15 resulting from fuel relocation. It was dropped from 16 the GI program in 1995. In 2006, tests at Argonne 17 National Lab and Halden indicated that fragmentation 18 and relocation could result in a loss of fuel 19 particles through the ruptured opening.
20 In 2008, RIL-0801 was issued discussing 21 recent high burnup research findings and nothing that 22 additional research on fuel dispersal was being 23 conducted, but stated that the current 62 gigawatt 24 days burnup limit is probably low enough to prevent 25 significant dispersal.
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In 2012, NUREG-2121 was issued discussing 2
the knowledge base of FFRD at the time. In 2015, 3
SECY-15-0148 was issued stating that 50.46(c) should 4
not be delayed to include FFRD, but that research will 5
continue to be conducted and future rulemaking may be 6
initiated if necessary. Basically, it was believed 7
that there is no imminent safety concern from FFRD up 8
to 62 gigawatt days per MTU.
9 In 2016, the draft final rule for 50.46(c) 10 went out. In 2021, RIL-2021-13 was issued documenting 11 the Office of Research's interpretation of FFRD 12 experimental research to date. In the RIL, the staff 13 defines conservative boundaries for FFRD-related 14 phenomena such as the amount of finely fragmented fuel 15 expected to be dispersed during a LOCA.
16 In 2022, SRM-SECY-21-0109 was issued by 17 the Commission directing the staff to address FFRD in 18 the IE rulemaking regulatory basis. In 2024, there 19 will be a PIRT conducted on fuel dispersal to help 20 identify further research needs, potentially develop 21 guidance, and to help focus NRC staff reviews of 22 applications that may evaluate FFRD.
23 MEMBER MARTIN: Question. This is Member 24 Martin. I appreciate this timeline. It's always nice 25 to see a background kind of distilled into a single NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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slide. A couple of things that I thought might have 2
been missing from this, first, since you threw the 3
PIRT on there, a couple of my colleagues back in the 4
day participated in 2001 in a LOCA PIRT with high 5
burnup fuel.
6 I notice that wasn't mentioned in any 7
regulatory basis, you know, sections in your report.
8 I do think that was worthwhile. At least, my 9
colleagues that I worked with once upon a time 10 thought, you know, their time was well spent. It does 11 address, you know, fuel dispersal. It basically 12 concluded that it was really a coolability question.
13 It kind of discounted the others.
14 So, one of the questions, at least 15 regarding to the PIRT is, or the new PIRT is what new 16 do you expect there? Would it really be a revision to 17 that old -- and its NUREG, I wrote it down, NUREG-CR-18 6744. Would it be a replacement? Are you going --
19 you know, addressing it maybe at a different scale of 20 phenomena? What's new?
21 MS. SMITH: I'm going to turn it over to 22 Joey or possible James. I know James is on the line.
23 Research is conducting the PIRT. Do you want to 24 clarify that?
25 MR. CORSON: Sure, yeah, this is James NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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Corson. I'm from the Office of Research at NRC. So, 2
basically, you know, we're certainly aware of that 3
earlier PIRT. This is considering even higher burnup.
4 So, I think back in 2000, 2001, it was 5
based on fuel up to 62 gigawatt days per MTU. There's 6
been, you know, a lot of research since then on even 7
higher burnup fuel and additional tests at Studsvik 8
and Halden with new data that we think is applicable.
9 And as you say, you know, coolability is 10 really the big concern, and so we're going to be 11 focusing on that particularly, you know, different 12 phenomena that can affect coolability of dispersed 13 fuel. I hope that answers your question.
14 MEMBER MARTIN: Sure, sure, of course, on 15 that, you know, looking at higher burnup, of course, 16 that's the goal. Tests at Halden, of course, went up 17 as much as what, over 90 gigawatt days per metric ton?
18 No one's talking about burning that far.
19 I will look around to see if I'm wrong 20 about that, but they're looking at what, you know, 21 near term, maybe 68, 75 kind of thing, and this, you 22 know, kind of puts some guardrails on any, on the work 23 given that the demand appears to be limited to 75. I 24 can -- I feel like anything beyond 75 might be a 25 distraction, right?
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I mean, we know it gets worse and becomes 2
more and more like sand as you get up, and then, of 3
course, there's a particular test at Halden where it 4
was at 92 and, of course, it cited in numerous 5
locations that, you know, it definitely dispersed and 6
was a mess, but I think, well, it's not applicable, 7
you know, I mean, at least as far as what people are 8
asking for. Would you put guardrails on that PIRT to 9
limit it to, you know, something a bit more consistent 10 with the marketplace?
11 MR. CORSON: Sure, yeah, so one minor 12 clarifying point. So, you know, people are thinking 13 about going up to maybe 75 gigawatt days per MTU peak 14 rod average burnup, so you could have, you know, 15 pellet average burnups that are quite a bit higher, 16 maybe ten percent higher.
17 Of course, it depends on your operating 18 history. So, really, we are talking about you could 19 have portions of the fuel rod that are in the low 80s 20 gigawatt days per MTU.
21 So, as you point out, you know, the Halden 22 tests do go up even higher and things get worse and 23 worse as you get higher, so that is going to be 24 considered, but I think there aren't that many tests 25 that are above where we're going to go, I think maybe NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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two or three Halden tests. I'd have to go back and 2
look at the exact number.
3 MEMBER MARTIN: Okay.
4 MR. CORSON: But your point is well taken 5
that certainly things get a lot worse when you go up 6
that high.
7 MEMBER MARTIN: And maybe a little bit to 8
the point, of course, you have the NUREG-2121 that was 9
published in 2012. I noticed that OECD, which, of 10 course, NRC participated in, of course, an extensive 11 program, actually published a, I would say, a fairly 12 informative and useful research report in 2016.
13 You know, it gets into some, you know, 14 quite a bit of detail. It wasn't cited in your 15 regulatory basis document. I thought maybe you might 16 want to add it to the story just so, you know, people 17 that look at this can appreciate this is not just the 18 U.S. looking at this.
19 You know, it's an international program, 20 and I think that report kind of gets into the level of 21 detail at least some stakeholders would be interested 22 in, so I'd just recommend that maybe you incorporate 23 that into, you know, the final version of that 24 document for public comment.
25 MR. MESSINA: That's a good comment.
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Thank you. We can definitely add those to create a 2
more comprehensive picture.
3 MR. CORSON: And this is James again.
4 Just to put you at ease, we are considering that 5
report as part of the PIRT. So, yeah, we should have 6
included mention of it in the regulatory basis, but, 7
you know, we're certainly aware of it, and at least as 8
part of the PIRT, it's part of our package of 9
materials.
10 MS. SMITH: All right, thank you. Are 11 there any more questions or comments on this slide?
12 VICE CHAIR KIRCHNER: What's your -- this 13 is Walt Kirchner. What's your objective for 14 completing the PIRT in terms of timeline?
15 MS. SMITH: The timeline for completing 16 the PIRT? Is that the question?
17 VICE CHAIR KIRCHNER: Yes.
18 MS. SMITH: I can touch base on that, and 19 James, you can correct me if I'm wrong, but they're 20 currently working with a contractor to organize the 21 PIRT later this year, and then the completion of the 22 PIRT report will be in early 2024.
23 VICE CHAIR KIRCHNER: Thank you.
24 MEMBER BALLINGER: So, by those words, the 25 PIRT report will be out in plenty of time for the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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rulemaking, which is due to be the end of 2024, 2
December 2024. So, the results of that PIRT could 3
affect the rulemaking effort itself, information which 4
we don't have now.
5 MS. SMITH: That's correct.
6 MEMBER BALLINGER: Thank you.
7 MS. SMITH: Okay, next slide? This slide 8
discusses the background and regulatory issue of fuel 9
dispersal. As stated in the timeline on the previous 10 slide, the 50.46 acceptance criteria date back to 1974 11 when FFRD were not known phenomena.
12 Acceptable approaches to demonstrate 13 compliance with the regulations have ensured that 14 catastrophic failure of the rod structure and loss 15 fuel bundle configuration are precluded. Fuel 16 dispersal would be a departure from precedent because 17 the fuel bundle geometry would be lost. Fuel 18 dispersal is not explicitly addressed within the 19 current regulations. Next slide?
20 MEMBER MARTIN: Question. This is Member 21 Martin again. So, in a previous life, I did LOCA 22 analysis for money, and realistic LOCA analysis, and 23 we would track, you know, various representative rods.
24 One of them would, of course, be a high burnup rod, 25 and, of course, we would have, I don't know, maybe you NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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want a first cycle rod.
2 Just about every time, it's going to be a 3
first cycle rod or an early second cycle rod that is 4
limiting, you know, as far as your peak clad 5
temperature is concerned or a rupture potential. That 6
high burnup rod just was pretty boring. It wasn't 7
getting the power.
8 You know, it -- and we had a NUREG-630 9
model in there and so, you know, whatever, it's an old 10 model, but the reg needs to be updated on new research 11 or design specific modeling, you know, that could 12 otherwise make it more realistic.
13 But, you know, when you think about 14 rulemaking and 50.46, you know, certainly the 15 coolability question is out there, but when you think 16 about other alternatives to putting your guardrails on 17 high burnup, one, you can do a lot of analytical 18 research. I think it will vet out my point.
19 Now, granted, you know, can you dream up 20 of a scenario where you have higher power and somehow 21 a late, you know, high burnup rod becomes limiting?
22 Well, you pile on certain conservatisms or, you know, 23 you have a lack of information even in a realistic 24 model, maybe it's possible.
25 All of that's kind of to lead up to the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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thought, well, it can get complicated, and what I 2
haven't heard or seen is any mention of, say, like Reg 3
Guide 1.157, which is the best estimate LOCA reg 4
guide. It hasn't been touched since its inception.
5 You know, for people that developed methods, it was 6
kind of the Bible.
7 As a matter of fact, I'm sure, I know fuel 8
fabrication and relocation is mentioned in there. I'm 9
not sure about anything about dispersal in any kind of 10 context, but possibly. Why not focus on a revision to 11 the reg guide and maybe allow some latitude for the 12 applicant to, you know, beat this to death with 13 analysis under, of course, a review topical in that 14 sense in the spirit of, say, what's being done with 15 Reg Guide 1.183, right?
16 MR. MESSINA: Yeah, I can take this. This 17 is Joe Messina. So, we are actually separate from the 18 increased enrichment rulemaking effort, and our 19 efforts here, we are in the process of updating Reg 20 Guide 1.157 to be more modern. And so, you know, can 21 they analyze it to death?
22 That's certainly a possibility, and that 23 would be more in line with alternative three presented 24 in the reg basis, but obviously, there are a lot of 25 challenges and it would take a lot of research in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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order to be able to model, you know, once the fuel 2
gets out of the rod, if this phenomena adds play to 3
it, you know, a 95/95 as all other LOCA phenomena are 4
modeled.
5 MEMBER MARTIN: And I agree, if the fuel 6
got out. My point was that it wasn't -- you know, we 7
were not seeing it get -- you know, we weren't seeing 8
ruptures.
9 Now, granted, it's been a long time. It's 10 been 15 years since I've played in that world. Who 11 knows that, you know, plants are pushing, but maybe 12 one of your stakeholders -- once you get out to public 13 comment, you might find something along those lines.
14 MR. MESSINA: Yeah, and as we go to higher 15 burnups, you know, some of the higher burnup rods end 16 up at little higher power than they used to be at, so 17 that combined with, you know, the increased fission 18 gas release, we do see a lot of high burnup rods 19 burst.
20 And our Office of Research did a study on 21 quantifying the number of rods that burst and the 22 amount of fuel that would be dispersed from these 23 rods. Actually, they published a paper in August in 24 NURETH, yeah.
25 MEMBER MARTIN: Okay, yeah, I wasn't so NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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sure about power, but pressure is definitely higher.
2 (Simultaneous speaking.)
3 MR. MESSINA: Yeah, we have that paper.
4 PARTICIPANT: We have that paper.
5 MEMBER MARTIN: Okay.
6 MS. SMITH: Okay, are there any other 7
questions or comments before I move to the next slide?
8 CHAIR REMPE: You mentioned that this 9
rulemaking is separate from the increased enrichment 10 rulemaking. Doesn't it seem like there should be some 11 sort of coordination?
12 MR. MESSINA: Well, this rulemaking -- the 13 fuel fragmentation and relocation and dispersal, the 14 rulemaking for this is part of the increased 15 enrichment rulemaking. I was talking the update to 16 Reg Guide 1.157 is --
17 CHAIR REMPE: Okay, I would have thought 18 this would be tied. I thought you just indicated that 19 there was a rulemaking that was separate for the 20 increased enrichment, and I thought this was one of 21 those.
22 MR. MESSINA: No, no.
23 CHAIR REMPE: Yeah.
24 MR. MESSINA: This is part of it.
25 (Simultaneous speaking.)
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MEMBER BALLINGER: This is Ron Ballinger.
2 What's the schedule for that update?
3 MR. MESSINA: I don't know at the moment.
4 John, do you --
5 MR. LEHNING: This is John Lehning from 6
Nuclear Methods and Fuel Analysis Branch. So, right 7
now where that is, there's a report that a contractor 8
has prepared to help us sort of collate a lot of the 9
research since 1988 or '89, and so we're in the stage 10 of reviewing that draft, and so I assume it might be, 11 let's say, over a year, maybe two years into the 12 future before we'd be ready to publish that updated 13 regulatory guide based on the review of this research.
14 It is a lot of work that's been done in 15 the last 30 or so odd years, and so I think some of 16 the coordination might come in depending on which of 17 these options gets recommended and ends up going 18 forward. As you know, we haven't made our 19 recommendation yet, but that could be a part of, for 20 example, alternative three, let's say. It could bring 21 this into a little bit tighter coupling.
22 MEMBER BALLINGER: But the rulemaking 23 schedule, such as it is, is December 2024, and what 24 you're saying is that update is quite a bit beyond 25 that.
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MR. LEHNING: At the present time, that's 2
the way it is, although things, as you know, could 3
change, and we did talk about some of the impacts to 4
the rulemaking schedule depending on bringing this 5
issue, and that wasn't part of the original plan, and 6
those have yet to be fully scoped out in terms of how 7
that might affect
- things, but,
- yeah, your 8
understanding is correct at this time, that that's 9
what I have at this time.
10 MEMBER BALLINGER: Thank you.
11 MEMBER MARTIN: Member Martin. Just a 12 real quick comment. I just, I know that it's part of 13 our practice. I definitely want to see that revision.
14 We recently had a draft guide that did not -- it 15 bypassed us before it went to public comment. I 16 definitely want to see that.
17 MR. MESSINA: Sounds good.
18 MS. SMITH: Okay, next slide? The staff 19 have developed five alternative licensing pathways 20 that could be pursued. The five alternatives are 21 considered mutually inclusive where combinations of 22 elements from multiple alternatives could be 23 considered.
24 The staff is also open to considering 25 other approaches not included in the five alternatives NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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based on public comments. Joe is going to talk about 2
the specifics of each alternative. Next slide?
3 MR. MESSINA: Yes, good morning, Jos 4
Messina again, Nuclear Methods and Fuel Analysis 5
Branch. I'm going to go into some details on each of 6
the alternatives outlined in the regulatory basis for 7
fuel dispersal.
8 To start off, I'll begin with the status 9
quo and consider maintaining it as one of the 10 licensing pathways. In this alternative, we would 11 keep the current regulatory framework mostly the same 12 without any major updates, and continue with the 13 precedent that a significant amount of fuel dispersal 14 should not occur.
15 Therefore, the most straightforward 16 licensing approach under this pathway would be to 17 demonstrate that rods susceptible to fine 18 fragmentation do not burst and thus lead to 19 significant dispersal.
20 It is expected that technical solutions 21 would need to be developed to prevent high burnup rods 22 from bursting, such as changes in fuel design and/or 23 core design, and well possibly the use of ATF could 24 also help. For example, coating may limit the balloon 25 size and the burst opening size, but that has not been NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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quantified yet.
2 I'll note that since the regulations do 3
not explicitly speak to fuel dispersal, allowing 4
significant dispersal may not technically require a 5
change to the regulatory framework, but this would 6
lead to a lot of regulatory uncertainty and challenges 7
by both industry and the NRC. Therefore, pathways 8
that consider significant dispersal are discussed as 9
part of other alternatives. Next slide, please?
10 The second licensing pathway proposed 11 rethinks a 50.46(a) style modification of ECCS 12 requirements. For those that are not familiar with 13 50.46(a), it was a final rule that went to the 14 Commission in 2010 and it risk informed LOCAs.
15 Specifically, it established a transition 16 break size. For breaks smaller than the transition 17 break size, LOCAs would be analyzed as they are today, 18 but for breaks larger than the transition break size, 19 less conservative assumptions and modeling could be 20 employed, such as allowing for credit of offsite 21 power.
22 In this licensing pathway, LOCAs above the 23 transitioning break size would essentially be treated 24 as beyond design basis. In beyond design basis 25 accident analysis, best estimate modeling and more NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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realistic assumptions can be employed, while during 2
typical design basis accident analysis, a 95/95 is the 3
typical standard for modeling.
4 The use of beyond design basis modeling 5
may help to show that no rods susceptible to fine 6
fragmentation end up bursting as a result of a LOCA, 7
but it still may be challenging. Therefore, this 8
pathway could be combined with other pathways that 9
analyze the consequences of fuel dispersal. There 10 would also be an obvious benefit outside of FFRD in 11 the LOCA analysis with this approach such as increased 12 margin to the PCT and oxidation limits.
13 I'll note that this would likely not be a 14 simple cut and paste from the 2010 rule. This would 15 be a modernization of the rule. We can update it with 16 any knowledge gained since 2010 or update it to better 17 capture today's landscape. Part of the work that 18 would need to be done would be to reassess the NUREG-19 1829 and NUREG-1903 LOCA frequencies.
20 MEMBER PETTI: Joe, just a question. So, 21 I assume there were statements of consideration that 22 were behind this change in the rule, in this, you 23 know, in 50.46(a), even though it never got -- this 24 never got implemented, right?
25 MR. MESSINA: Correct.
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MEMBER PETTI: But did you go as far as to 2
have those things in consideration --
3 MR. MESSINA: Yeah, we looked at the FRN 4
and all of the relevant documents that went to the 5
Commission.
6 MEMBER PETTI: Sure, this, in my mind, 7
you're moving away from 50 years of precedent with 8
this rule, so this is a biggie in my opinion, at least 9
in the draft letter that I -- I didn't put to Ron.
10 This is one of the key points.
11 So, it would be interesting, I think, to 12 pull that up. At least I think it would help us as we 13 think about it, but I just wanted to make sure I 14 understood because this is before my time on the ACRS.
15 Thanks.
16 MR. MESSINA: Yeah, there aren't many 17 people at the NRC people left from that effort.
18 MEMBER PETTI: Elijah had to dig deep.
19 (Laughter.)
20 MEMBER ROBERTS: I was wondering if you 21 have any, you know, insights on the word may you've 22 underlined there, like has there been a sample 23 calculation done or some sort of, you know, an 24 estimate based on other work, that, you know, you 25 think of as may?
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MR. MESSINA: So, the reason I underlined 2
may is because under this alternative, we proposed 3
keeping, maintaining the precedent that significant 4
fuel dispersal should not occur, and using best 5
estimate modeling may not be able to show that all 6
rods do not, all high burnup rods do not burst, and 7
this is --
8 We included the may due to the 9
calculations in the NURETH paper from August, which 10 showed, yeah, I think it was about 75 percent of the 11 core burst. I mean, not all of those would be high 12 burnup, but a still significant amount of high burnup 13 rods would burst.
14 MEMBER ROBERTS: So, it's likely not?
15 MEMBER BROWN: Uninitiate Charlie Brown, 16 uninitiated person in the detail that you all work 17 with. Is this a result of now going to the higher 18 enrichment and it wasn't a problem when you start and 19 you keep yourself below five percent, a wider 20 dispersal or a wider range of burst fuel rods?
21 MR. MESSINA: So, yes, the amount of 22 dispersal would increase as we go to higher burnups 23 and, you know, there's more fragmentation of the rods, 24 so more of the fuel pellet is susceptible to 25 dispersal. And as we go to higher burnups, more high NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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burnup rods end up off of the periphery of the core, 2
so it would be at higher powers and possibly more 3
likely to burst.
4 MEMBER BROWN: So, we're now going to be 5
willing to accept a worse result by going to this than 6
we have -- am I reading this correct?
7 MEMBER PETTI: No.
8 MEMBER BROWN: I'm not an expert on this.
9 MEMBER PETTI: No, no, Charlie, I think --
10 I mean, the calculations that were done suggest that 11 you may not be able to demonstrate, you know, with a 12 sharper pencil.
13 MEMBER BROWN:
What we used to 14 demonstrate.
15 MEMBER PETTI: Right, when you move to the 16 higher burnup.
17 MEMBER BROWN: To the higher burnup.
18 MEMBER PETTI: But, that said, the 19 calculation has -- there's a lot of assumptions around 20 that calculation. The fission gas release which is 21 driving the burst behavior has got a lot of 22 uncertainty on it. How you calculate the stress on 23 the clad and the burst, there's multiple models that 24 show different behavior. So, you move deeper into 25 analysis hell is what --
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MEMBER BROWN: Without experimental 2
verification?
3 MEMBER PETTI: There is -- some of the old 4
models have experimental verification. Some of the 5
new ones, let's call them fundamental, less empirical, 6
it's kind of a mix. So, all of this stuff has to be 7
kind of figured out, right, and that's why I describe 8
it as -- it's not a slam dunk.
9 More calculations have to be done, you 10 know, I think, with more sensitivities to really kind 11 of understand better. I mean, just to do what they 12 did was a pretty big calculation, so, and then to take 13 the next step to sensitivity, it's just, it's a time, 14 you know, thing to get it all.
15 MEMBER BALLINGER: The limit that the RIL 16 suggests is 55, above 55, plus other criteria, you get 17 dispersal.
18 MEMBER BROWN: Above 55 gigawatt days, I 19 think I remember hearing 60 in a lot of our previous 20 meetings.
21 MEMBER PETTI: So, there is this 22 inconsistency that one of the documents said it's not 23 a problem below 62, but then the RIL sort of says 24 there is a problem that you could interpret between 55 25 and 62. But there's some nuance in there that I think NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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has to be applied.
2 MEMBER BALLINGER: But you have to have 3
first.
4 MEMBER BROWN: I understand that, but 5
fundamentally it means you get more dispersal of 6
obviously fuel throughout the reactor coolant system, 7
and every place else, it's just not a good idea in 8
general. And we don't have any real test data that we 9
10 MEMBER PETTI: No, there's a bunch of 11 data, we reviewed it in the RIL, and there's issues 12 there, you can go back and read our letter. We 13 weren't convinced that all the experiments are 14 prototypic enough that you may not be getting some 15 false negatives.
16 MEMBER BROWN: I didn't remember that 17 part.
18 MEMBER PETTI: Yeah, Ron and I worked on 19 that one.
20 MEMBER BROWN: Yeah, that's not exactly in 21 my radar.
22 MEMBER PETTI: So, again, you'll see, I 23 mean these are all the things you've got to consider 24 as part of the option space, which this is multi-25 dimensional, it's not easy. So, this discussion I'm NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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sure will happen again later.
2 MEMBER MARTIN: I wanted to clarify one of 3
the statements, of course it's your statement, but the 4
best estimate modeling comment, you made a note of 5
course, you can apply more realistic assumptions.
6 Every fuel vendor has a LOCA best estimate methodology 7
that already looks at 95/95, and that was mentioned.
8 When you get into severe accident space and that's 9
redefining the break size to redefine basically what 10 a design basis accident is, or what the severe 11 accident is with regard to LOCA.
12 Typically you're looking more as a 50/50, 13 more of a median. Now, you do that, and that's a huge 14 margin. Typically the margin is just staying with 15 best estimate. Well, with a statistical approach, are 16 like as much as 200 F for standard deviation, so you 17 could have 2 sigma 400, 500, that kind of range. So, 18 yeah, 50/50 would be tremendous.
19 If these designs already comply with the 20 95/95, your temperatures would be solo particularly 21 for a realistic high burn up rod. I'm sure it would 22 show no rupture.
23 MR. MESSINA: Yeah, the worry for the high 24 burn up rods really isn't related to PCT or oxidation.
25 It's more, now that it's fuel dispersal, so for the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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most part we worry about PCT and oxidation for, as you 2
said, the lower power rods at the high power -- the 3
lower burn up rods at the high power. And then now 4
that we introduced this problem basically of fuel 5
dispersal at high burn up.
6 Obviously if fuel disperses, can that fuel 7
end up heating both sides of the rod, and lead to 8
higher PCTs? That's obviously could be something that 9
could occur. But we're looking into that more in the 10 purview.
11 MEMBER MARTIN: Right. And I can't help 12 it, passion here, when we stylize these LOCA analyses, 13 we impose a peaking, and typically it's not realistic 14 peaking. Those are peakings that may be you have a 15 hypothetical xenon transient or something like that, 16 and it pushes the power up or down. Usually we pick 17 an up, because from a thermal hydraulic standpoint.
18 But you don't burn in fission products 19 really. So, when it comes to shutting down, you're on 20 decay heat, everybody, as far as I know, is biasing 21 their post SCRAM power with an assumption that you 22 burn in your fission products, and have decay heat 23 that is affecting, and that has a huge effect on your 24 temperatures.
25 And no one has probably bothered to think NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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about making a more sophisticated decay heat model, 2
but that might be one of the things. It's a huge 3
concern, particularly when you're in this space where 4
you're talking about what might break, and spill out.
5 You took that out, that might eliminate it too. But 6
something to kind of put on your radar. We have very 7
simple decay heat model, and if you put some realism 8
in there, again, that might go away.
9 So, if you're doing a little bit of 10 analysis, the codes would all need to be modified to 11 do that. But I think you'd also find that 12 temperatures come way down.
13 MR. MESSINA: Yeah, thank you. If there's 14 no other questions on this slide, next slide please?
15 So, the third licensing pathway proposed in the 16 regulatory basis is to provide a safety demonstration 17 of post fuel dispersal consequences. I alluded to 18 this a little bit before this alternative. And so, 19 phenomena such as core coolability, recriticality, and 20 long term cooling would need to be addressed, just as 21 any other LOCA phenomena, which is to say modeled at 22 95/95 probability and confidence.
23 As a part of this, guidance would be 24 developed regarding the analysis of the consequences.
25 We are sponsoring the PERT that was mentioned before, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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and this would help us to issue guidance with the rule 2
if we go ahead with this alternative. This guidance 3
though, would have to be relatively high level, and 4
conservative though, since there has not been a ton of 5
experimental research on the consequences of fuel 6
dispersal conducted to date.
7 But we envision that the PERT would inform 8
future experimental research that can be conducted in 9
parallel, and in subsequent years, and this research 10 could be used to update the initial guidance that goes 11 out with the rule to be more specific and less 12 conservative.
13 VICE CHAIR KIRCHNER: Joe, you mentioned 14 95/95, my reaction to that is I don't even know where 15 to start to frame my comments, it makes no sense. We 16 don't have that kind of modeling capability once we 17 get beyond the intact geometry and start dispersing 18 things. I mean 95/95 is good for CHF correlations and 19 so on, but to think you're going to get 95/95 on a 20 stochastic process like this, I mean you don't even 21 know where the ballooning is going to take place.
22 You're just going to assume in your 23 analysis a threshold, that's where you will calculate 24 ballooning. In reality that's not the way ballooning 25 happens. There's so many variables that we can't NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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model that well, that if you go down this route, 2
you're going down the route that the LMFPR people were 3
going down, and 95/95 just doesn't make any sense to 4
me at all.
5 You're in a different space completely 6
than the traditional LOCA analysis with an intact 7
geometry. So, I'm just reacting to the 95/95. We can 8
model this, we've got things like MELCOR, but to think 9
you're getting 95/95, it's a highly non-linear 10 problem.
11 MEMBER MARCH-LEUBA: I will concentrate 12 not on 95/95, but on the calculation, and I'll be 13 happy to do a 50/50, the best testing. Which you 14 probably can't.
15 VICE CHAIR KIRCHNER: It's extremely non-16 linear space once you get to this --
17 (Simultaneous speaking.)
18 MEMBER MARCH-LEUBA: The only way this can 19 be conceived is by Appendix --
20 (Simultaneous speaking.)
21 VICE CHAIR KIRCHNER: This is stochastic 22 23 MEMBER BALLINGER: This is a nightmare.
24 The old PNNL, they did a whole bunch of burst tests 25 back when you and I were much younger, and they tried NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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to analyze the results, and they simply threw up their 2
hands and said we can't figure anything out. And they 3
spent a lot of money on those burst tests.
4 MEMBER PETTI: Well, you remember the old 5
code FRAPT.
6 MEMBER BALLINGER: Yeah.
7 MEMBER PETTI: I mean we've been 8
calculating this stuff, well, trying to calculate it 9
forever. I agree, it's not -- I'd call it analysis 10 hell.
11 MEMBER BALLINGER: It's an exercise in 12 hallucination.
13 VICE CHAIR KIRCHNER: It'd be one thing to 14 say best estimate, but 95/95 is an expectation now 15 that's just not credible. And I came out of this 16 world with TRAC, so hating myself.
17 MR. SCHULTZ: Joe, this is Steve Schultz.
18 This is an area where I would have underlined and 19 bolded may impact increased schedule.
20 MEMBER BALLINGER: Steve was around when 21 they did those burst tests.
22 VICE CHAIR KIRCHNER: That's one member's 23 comment, Joe.
24 MR. MESSINA: Thank you, appreciate that.
25 Next slide please. So, the fourth licensing pathway NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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would be to provide a generic bounding assessment of 2
dose, and use risk insights to address post fuel 3
dispersal consequences. Currently there are dose 4
criteria for most DBAs, but for a 50.46 LOCA that is 5
mitigated, we assume the consequences are bounded by 6
7 Or the maximum hypothetical loss of 8
coolant accident dose, which assumes an unmitigated 9
LOCA that leads to a substantial melt of the core, 10 which is talked about in Reg Guide 1.183. This option 11 though, would establish a dose criterion for the LOCA 12 analyzed under 50.46 with fuel dispersal.
13 Licensees would need to demonstrate the 14 ability to predict the source term for LOCA with fuel 15 dispersal, or be directed to use some fraction of the 16 MHA LOCA source term based on the amount of fuel that 17 is predicted to be dispersed. Regarding the other 18 consequences of fuel dispersal, in this option we 19 postulate risk insights could be used to address them.
20 For example, insights from operating 21 experience, and other regulatory requirements, and 22 industry initiatives may be able to be used, such as 23 the severe accident mitigation guidelines, TMI action 24 plan requirements, et cetera. That's all I have on 25 this slide.
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MEMBER BROWN: If you have widespread 2
bursting, which you've referred to in your comments, 3
how does this affect your ability to shut down the 4
reactor? Is there the possibility of not being able 5
to shut it down, and thus have control room issues, 6
and thus have to have alternative systems? I'm trying 7
to get a grip on how massive this fuel dispersal is, 8
and what its impact is on the ability to even shut it 9
down.
10 Because this is a LOCA, can you get them 11 in in time, do you have the sensors, the data to be 12 able to get the rods in before you have a more 13 widespread disruption of the fuel elements and 14 ruptures? I haven't heard anything in the discussions 15 on the ability to shutdown, other than were it a LOCA, 16 we normally assume we can shutdown when we've got a 17 LOCA.
18 Or at least that's been my past experience 19 at my old jobs, and what I've heard up until then.
20 And I haven't heard anything at all about on any 21 problems with shutting down the reactor under these 22 circumstances, which would seem to me, comes into play 23 somehow.
24 MR. MESSINA: Yeah, and the consequences 25 as I said before, the consequences of what happens, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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and what are the effects and impacts once the fuel 2
leaves the rod, we're still looking into them.
3 MEMBER MARCH-LEUBA: With respect to 4
shutdown in LOCA, you use SCRAM within the first 5
second, and then LOCA --
6 (Simultaneous speaking.)
7 MEMBER BROWN: I would like to think, I 8
mean I agree with --
9 MEMBER PETTI: It just takes a little 10 longer to get there.
11 MEMBER MARCH-LEUBA: Yeah, on the LOCA 12 consequences of decay heat generated, the control rods 13 will need half an hour.
14 MEMBER BROWN: So, based on your opinion, 15 in my old job I would have assumed the same thing 16 also, a very quick response, because we can do that, 17 but I'm not -- but this is a different configuration 18 that I'm used to, so that's why I'm asking the 19 question.
20 MEMBER MARCH-LEUBA: With respect to 21 criticality, the designers make a big effort to put 22 their U235 in the most favorable condition for 23 criticality.
24 (Simultaneous speaking.)
25 MEMBER MARCH-LEUBA: You do this first, it NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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goes in a favorable geometry, so I wouldn't worry 2
about criticality if the rods went in, you have a LOCA 3
and an ANWAS (phonetic), which is a completely 4
different thing, but we typically analyze it.
5 MR. MESSINA: Okay, next slide please.
6 So, the fifth licensing pathway presented in the reg 7
basis is to use probabilistic fracture mechanics to 8
show that leaks in large pipes will be identified 9
before failure, precluding the need to analyze ECCS 10 performance during large break LOCAs. This would be 11 a major departure from current practice, and would 12 have implications outside of LOCA space as well.
13 This licensing approach builds on industry 14 initiatives, such as EPRI's alternative licensing 15 strategy that was presented to ACRS a few months back.
16 This licensing pathway would use XLPR, or the 17 extremely low probability of rupture code, and the 18 leak before break, or LBB concept to show that leaks 19 in large pipes would be able to be detected, and 20 operator action would be able to be taken to shut down 21 the reactor with sufficient probability before a pipe 22 breaks and the large break LOCA occurs.
23 If the large break LOCA does not occur, 24 this would prevent any fuel rod failures, and thus, 25 fuel dispersal. This alternative also states that if NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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it can be shown that the large break LOCA does not 2
occur with these methods, then ECCS performance would 3
not need to be analyzed for the large break LOCA.
4 MEMBER MARCH-LEUBA: So, as a licensee, I 5
find alternative five very appealing, and you can --
6 I mean you know, that's what they want to do. So, 7
what is the staff doing to prepare for that review?
8 You are not going to recommend one, two, three, four, 9
or five. But we should anticipate licensee is going to 10 w a n t t o p u s h t o w a r d s f i v e.
11 12 MR. MESSINA: Yes, and we make our own 13 decision based on stakeholder feedback, considering 14 safety, defense in depth, and maintaining all of 15 those. So, just because industry wants something does 16 not mean we will bend over.
17 MEMBER MARCH-LEUBA: In the near medium 18 time future, you are going to get a lot of submittal, 19 a lot of requests to tell me that XLPR can calculate 20 these things with sufficient accuracy and robustness 21 to be able to accept it. So, the staff needs to be 22 preparing for that.
23 MR. MESSINA: Yes.
24 MEMBER BALLINGER:
- Again, it's my 25 understanding that this is actually happening. That NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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EPRI, there's a submittal that will occur in the first 2
quarter that does this. So, that's still the case?
3 MR. MESSINA: As I know, yes.
4 VICE CHAIR KIRCHNER: Joe, can you 5
distinguish this one from number two, the transition 6
break size? I mean basically when you go into 7
analysis of this, you would probably look at a break 8
size that you could withstand without FFRD in 9
alternative five. I presume that same surge is going 10 to happen in alternative two. So, is there a 11 definition for transition break size?
12 MR. MESSINA: So, transition break size as 13 proposed in 2010, in the initial 50.40 CFR rule, we do 14 anticipate that the transition break size would have 15 to be established for alternative five, and that those 16 were based on LOCA break frequencies in the two NUREGs 17 that I previously mentioned. And for PWRs in 2010, it 18 was the largest attached pipe to the main coolant 19 piping, which is the pressurizer surge line with an 20 inside diameter of about 11 to 12 inches.
21 For BWRs, it was the largest attached feed 22
- water, or residual heat removal line inside 23 containment, which has a diameter of around 22 to 24 24 inches, and these were derived to match a break 25 frequency of one to the negative fifth per year.
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VICE CHAIR KIRCHNER: So, I'm thinking in 2
terms of regulatory certainty, and such on one hand 3
five would be generic if I could use that word, go 4
figure out and demonstrate to us what that break size 5
is. Two would really codify the existing fleet, and 6
our knowledge of how the NSSS systems work for the 7
existing fleet, and the database that supports that, 8
which would be the same database for number five, to 9
demonstrate your probabilistic fracture mechanics.
10 The code is basically sound, would it help 11 if between two and five, is there any advantages?
12 They both would have to do the same analysis in the 13 end to demonstrate to you, the regulator, that they've 14 avoided significant rupture and dispersal.
15 MR. MESSINA: So, no, alternative five is 16 kind of drastic in that after the transition break 17 size is established, above that we don't look at ECCS 18 performance.
19 MEMBER MARCH-LEUBA: So, you basically 20 remove LOCA from chapter 15 analysis?
21 MR. MESSINA: Correct.
22 VICE CHAIR KIRCHNER: Or LOCA --
23 (Simultaneous speaking.)
24 MR. MESSINA: Large break, yeah.
25 MEMBER MARCH-LEUBA: With two you still NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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have a LOCA analysis from the last break size, but 2
used a different, more relaxed methodology.
3 VICE CHAIR KIRCHNER: So, you could 4
potentially not do a LOCA analysis under five?
5 MR. MESSINA: A large break, you'd still 6
have to address below the transition break size of a 7
small break.
8 MEMBER PETTI: It's defined as outside the 9
design basis, right? In option five.
10 VICE CHAIR KIRCHNER: So, what size LOCA 11 would you have that demonstrate? Because let's be 12 realistic, pipes fail, systems, so at some point, one 13 would expect that you prudently in defense in depth, 14 you would allow for a certain break, and then 15 demonstrate that your ECCS systems -- I mean taken to 16 its extreme, you said it's not probable that we have 17 a large break. Then you can take away the ECCS 18 systems, and it doesn't sound like a good step.
19 MEMBER BROWN: That would be next on the 20 request line.
21 VICE CHAIR KIRCHNER: I said that 22 rhetorically, I didn't mean that. But you take it 23 logically, there's no logically, there's no large 24 break LOCA, we don't need accumulators on a PWR as an 25 example.
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MR. MESSINA: Yeah, so the way I think we should 2
look at the options are it's a sample space of 3
options, and we try and consider the bounds of that 4
sample space, and will consider within the sample 5
space as well. So, these are bounds, we'll consider 6
them, but we'll also consider within the bounds.
7 MEMBER MARTIN: One thing you have to 8
consider when you're talking about break size, if you 9
took large break LOCAs kind of off the table, or into 10 a different space, if there was margin, what are the 11 fuel vendors, the plants going to do, right? Now, 12 likely they're non-LOCA limited, frankly, but if they 13 weren't, they're going to crank up those power plants, 14 and then all of a sudden --
15 MEMBER PETTI: That's the interesting 16 question, right? If this goes away, what limits a 17 PWI?
18 MEMBER MARTIN: Right.
19 MEMBER PETTI: Probably ENB one of them, 20 and how big the steam generators are because you can't 21 increase indefinitely, but it's an interesting 22 question.
23 MEMBER MARTIN: I think there are already 24 plants that are non-LOCA limited because of progress 25 with best estimate LOCAs.
But nonetheless, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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hypothetically, if there was more margin because of 2
this being removed, and there was room with small 3
break, they would definitely crank up the power, and 4
then you might find -- I mean small breaks, you can 5
have pretty hot small breaks.
6 Now, I don't think everybody, when I say 7
everybody, the fuel vendors and plants are necessarily 8
on best estimate small breaks, obviously Westinghouse, 9
I'm not sure where other vendors are with small break.
10 And I assume you're still saying -- I mean Appendix K, 11 if you're still on Appendix K, small break method, 12 it's really off the table, right?
13 I mean once upon a time 50 years ago, kind 14 of the feeling was the conservatisms in Appendix K 15 were such that you covered the unknown unknowns, and 16 this of course would have been in that category back 17 then. I thought I saw that actually in the regulatory 18 basis document, that opinion. So, taking Appendix K 19 off the table, you could find small break case that 20 got up there.
21 I still think it probably wouldn't affect 22 a late burn rod, but nonetheless, if the door is open, 23 people are going to walk through that door too. So, 24 keep in mind, the final point there is I'm not so sure 25 a transition break really matters. LOCAs will be NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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there regardless.
2 MEMBER BROWN: Sometimes to excess.
3 MR. MESSINA: Next slide please. So, we 4
provided five licensing pathways in the regulatory 5
basis, but at the time we do not provide a recommended 6
pathway because we feel that stakeholder feedback is 7
important before making such a decision. We provided 8
six questions to the public in the FRN, and the reg 9
basis on fuel dispersal alternatives to better help us 10 make a decision.
11 And as we previously stated, these 12 alternatives are not mutually exclusive. We will 13 consider combinations of the alternatives presented, 14 or any other proposed pathways that may not have been 15 discussed. Overall, as I said, I like to think of it 16 as a sample space of options. We provided some 17 boundaries for the sample space, we're considering 18 those boundaries, as well as options within the 19 boundaries, and may consider options outside of the 20 boundaries.
21 Maybe there's a brilliant idea that we 22 didn't think of, and we didn't propose in the reg 23 basis, but we'll see based on public feedback.
24 MEMBER BROWN: Why do you use the term 25 stakeholder perspectives? I mean that's like an NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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opinion, they'd like to have this, or they'd like to 2
have that. Why shouldn't they, if they want one of 3
these, why shouldn't they provide some technical basis 4
for why one of these is acceptable, even though you 5
have questions relative to the alternatives you've 6
developed?
7 Isn't it upon them to demonstrate the 8
satisfactory application of even what was alternative 9
five, where you have no restraints at all, which from 10 what I hear from the other discussion, and not being 11 an expert on this, although having some background on 12 it, is you were saying that's what you're kind of 13 expecting them to go to. I heard that in a couple of 14 comments during your all's discussion.
15 So, I don't understand the thought process 16 perspective. If I was a regulator like you all are, 17 I would expect the industry to tell you why is this 18 okay in my plant. Why do you have to justify the 19 alternative without them providing the analysis, and 20 basis, and substantial reasons why these alternatives 21 will not be an additional risk to the public? That I 22 don't understand, why you have to justify them doing 23 it, as opposed to them showing you why it's okay.
24 MEMBER BALLINGER: Charlie, that's what 25 ALS is, option five. And there's a submittal that's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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going to happen, and we're anticipating getting EPRI 2
in here, or whoever does it, to give a more detailed 3
presentation. We did have a presentation from EPRI as 4
one of the four things we have, and they mentioned 5
ALS. But it wasn't a presentation on ALS.
6 MEMBER BROWN: ALS is alphabet soup for 7
me, say the ALS again?
8 MEMBER BALLINGER: Alternative licensing 9
strategy.
10 MEMBER BROWN: Okay, thank you.
11 MEMBER HALNON: In all this though, the 12 regulatory tools to get answers, you just don't have 13 enough information to put a generic safety issue, or 14 a 50.54F letter, I mean there's just not enough to 15 force the licensees right now to spend a lot of money 16 on analysis without having a back fit, or some other 17 issue that you have to deal with in regulatory space.
18 So, there's a lot of questions, but there's not a 19 regulatory tool other than the FRN that you have out 20 right now to gather information to see if there really 21 is a generic safety issue.
22 I mean, our biggest relocation event in 23 TMI showed that criticality wasn't a problem, 24 coolability wasn't a problem, dose wasn't a problem to 25 the workers, we've got all this stuff, now granted, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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that was brand new fuel, and obviously a serious 2
event, and you don't want that to happen. But until 3
you get to enough answers to say I can issue a generic 4
letter, or you can issue a 50.54F, you can't force the 5
licensees to do anything based on, in my mind, based 6
on just what we have so far, which is I think I might 7
have an issue. But they should --
8 MEMBER BROWN: Well, but why isn't the 9
licensee, I mean this is to their benefit if they can 10 operate at higher power enrichments, and therefore 11 whatever your magic 62 goes to 85 or whatever the 12 number might be. It seems to me if that's in the 13 benefit, I mean in my old world if I wanted to do 14 something different, I had to demonstrate why, now I 15 would propose to the rest of my world why this is okay 16 and why we think it's satisfactory to go forward 17 without any.
18 I didn't wait for them to tell me what I 19 needed to do, I had our program, at least that's what 20 I remember.
21 MEMBER HALNON: Right, but that's why 22 alternative five is not being --
23 24 MEMBER BROWN: I've been out of it for a 25 while, so I don't think they've deviated that much.
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MEMBER HALNON: That's why alternative 2
five right now says may impact increased rule making 3
for enrichment is not one of them on the table right 4
now. So, you don't want to really increase the 5
schedule for enrichment, right? I mean, this is out 6
there, but it's not necessarily a direct road block to 7
the higher enrichment at this point.
8 MEMBER BROWN: Well, are they just -- with 9
62 I thought they were looking at, maybe I lost it 10 somewhere along the line with all the numbers. 62, 11 they want to go something higher than 62, where you 12 are today, is that what they want to do?
13 MR. MESSINA: Yes, the industry would like 14 to go above 62 gigawatt days rod average.
15 MEMBER BROWN: To where potentially?
16 What's in sight, not aspirational, but what would be 17 reasonable in sight?
18 MR. MESSINA: I've heard 68, and up to 75.
19 MEMBER BROWN: Fairly substantial change, 20 20 percent in one case.
21 CHAIR REMPE: We have a --
22 MR. BLEY: This is Dennis Bley, and the 23 staff can correct this if I say it wrong, but I 24 believe there's a congressional mandate to help the 25 industry in this way, is that so? At least that's the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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way I read some of the last couple of laws that affect 2
us.
3 MR. MESSINA: Yeah, NEIMA, the Nuclear 4
Energy Innovation and Modernization Act, I believe 5
addresses that.
6 MEMBER BROWN: Okay, but does that -- you 7
all don't go out and do it, you don't run experiments 8
at any of the facilities, I mean that's -- you're a 9
regulator that evaluates the plants, and what they do, 10 and what they can do, and what their limits are. It's 11 not a matter of you developing an entire regime of 12 operating space for people to be able to go into. DOE 13 may have that responsibility if they even recognize 14 it.
15 CHAIR REMPE: At the beginning of the 16 regulatory basis, correct me if I'm wrong, but you 17 raised this document, it talks about yeah, we can let 18 them come in one by one with exceptions, or we can try 19 and be proactive, and initiate rule making to be more 20 efficient as a regulator. And all the staff is doing 21 in this document, for various regulatory requirements 22 that they've identified, or recommending where they 23 can, options.
24 And in this last case, there's a lot of 25 options they haven't decided yet, and they're trying NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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to do this. So, the research to support what they 2
ultimately come in is way down the pipe is my opinion, 3
and you can correct me on this. But I'm also a little 4
concerned about time, and so that's why I'm kind of 5
trying to answer this in a way --
6 MEMBER BROWN: You're trying to tell me 7
not to ask any more questions.
8 CHAIR REMPE: No, I would never do --
9 well, maybe I would do that, Charlie, but I'm trying 10 to give an answer to try and take my perception of 11 that, is that a sufficient answer to the question? So 12 we can get to the last slide?
13 MR. BENAVIDES: Yeah, this is Phil 14 Benavides, what we're doing here is we're trying to 15 create a regulatory framework that allows the 16 licensees to go ahead and submit license amendment 17 requests if they're making modifications at their 18 facilities.
19 MEMBER BROWN: My only point being is that 20
-- let me, understand, I will try to restrain myself.
21 No, I won't. But I have no problem with doing what 22 you're doing, that's not it. But developing a basis 23 for why that is okay, seems to me that has to be with 24 the people that want to do it. You say there's some 25 options we can consider. You have to tell us how we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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can justify that from a regulatory basis, and accept 2
that as a basis for going forward.
3 And I haven't heard, you're just throwing 4
perspectives, well we'd like to do that. It just 5
seems to me a more direct way of phrasing this would 6
have been a little bit, I didn't quite get that. I 7
understand where you're all going, I understand you're 8
trying to set a framework where they can consider 9
alternatives, but you're not the developer of the 10 basis for why they can go do that.
11 You don't develop the tests, you don't 12 have test reactors, you're not getting it, there is no 13 data all to --
14 CHAIR REMPE: Charlie, the basis is for 15 rule making, not anything else, right?
16 MEMBER BROWN: But if you set the rule out 17 there, and it's higher, then they --
18 CHAIR REMPE: They have to submit it to 19 the commission to go forward with the rule making, 20 okay? Am I saying that correctly, folks?
21 MEMBER BROWN: It just means the okay on 22 it.
23 MR. MESSINA: Yes, the commission has to 24 approve.
25 MEMBER BROWN: I understand that, I do NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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understand that. All right.
2 MEMBER BALLINGER: And by the way, it's 3
the commission that specified FFRD had to be included 4
by the way. It was not in the original SRM.
5 MEMBER BROWN: Well, I mean -- I could 6
make some comments about that, but I won't, not in 7
this forum anyway. All right, I'll quit, I'm sorry.
8 My job is to be inquisitive, even if I make (audio 9
interference).
10 MR. MESSINA: Next slide please. So, I 11 just put all the alternatives on one slide if it 12 helped with seeing it as any discussion comes up. But 13 that concludes my presentation. So, if there are any 14 additional questions?
15 MR. SCHULTZ: Joe, was there any specific 16 questions in this area at the public meeting last 17 week? This is Steve Schultz.
18 MR. MESSINA: Yeah, Steve, good point, 19 sorry, I meant to mention the public meeting. There 20 were a few questions, not very technical detailed, but 21 two of the questions that I'll highlight were from 22 NEI. One was how are we using the NURETH paper in 23 this regulatory -- in this process. And the other was 24 more wise, answering the how can they answer the 25 questions, and how should they answer the FRN NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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questions, and provide their perspectives as well as 2
answers to the questions.
3 MEMBER BALLINGER: Let me try and restate 4
the time line that we're dealing with here. We have 5
this document which we're considering, we have 6
obviously the FFRD is hanging out there. We have a 7
PERT that's going to occur sometime, I have it early 8
2024. We have the EPRI submittal, which is supposedly 9
in the first quarter of 2024. And then the draft rule 10 would have to be ready before December 2024.
11 And Lord willing, if the creek don't rise, 12 Reg Guide 1.157 might get out there in draft form, the 13 modification. Am I getting it about right? Is there 14 something else in the time line that influences what 15 we're doing here that we need to think about?
16 MR. MESSINA: I believe --
17 MEMBER BALLINGER: The PERT, and the 18 submittal, that adds information, which is important 19 for this.
20 MR. MESSINA: Yeah, I believe those are 21 the main things that we expect in this process. And 22 all of the slides say as we get the public feedback, 23 and assess the options more, we'll figure out any 24 impacts to the schedule from the FFRDL terms.
25 MEMBER BALLINGER: Okay. Public comment?
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Okay, so we thank you very much.
2 MR. MESSINA: Thank you.
3 MEMBER BALLINGER: Now it's time to go out 4
for public comments. If there are members of the 5
public either out there or in the room that would like 6
to make a comment, I don't know whether he disappeared 7
or not. He's there. Let's try the outside ones 8
first. Are there members online that would like to 9
make a comment? Please state your name, and make your 10 comment. Are we online?
11 CHAIR REMPE: We are. If you're on a 12 phone line sometimes you have to hit star six to 13 unmute yourself, but the rest of the folks on 14 computers can just unmute their mic, but I'm not 15 seeing anybody wanting to do anything.
16 MEMBER BALLINGER: Okay, now with that 17 being the case, we have in the room, does anybody --
18 there are more than one.
19 (Simultaneous speaking.)
20 MEMBER BALLINGER: And speak loud.
21 MEMBER BROWN: Tell him to move closer.
22 MEMBER BALLINGER: No he's fine.
23 MR. PARILLO: This is John Parillo, I work 24 with Elijah in the Radiation Protection and 25 Consequence Branch. I have had some long concerns NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
125 1
with design basis in those criteria, which I submitted 2
a PRM about, it's PRM 50-129. But what I would like 3
to request that the committee, in contemplating any 4
change to the control room criteria, consider the 5
change in relationship to the offsite criteria.
6 There's a disparity not only in the number 7
in that criteria, but also in the verbiage. For 8
instance the offsite criteria was always presented not 9
as an acceptable dose to the public, but rather as 10 what they called a reference to the evaluation of 11 accidents at very low probability. So, basically that 12 was what Elijah's referring to as a figure of merit.
13
- However, the GDC19 has now been 14 incorporated into 50.67 it starts out saying adequate 15 radiation protection is provided by limiting the dose 16 to five rem. So, there's a disparity not only in the 17 numbers, the values, but in the concept behind them.
18 And I would encourage you to consider having a basis 19 that apply to both of those values. In my PRM I 20 suggest it as a voluntary rule, use of a health 21 physics basis of ten rem.
22 But that's not really what I want you to 23 consider. What I want you to consider is looking at 24 these values, the control room, and off flow with the 25 same level of consistency. Because right now, I think NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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we're -- at least I'm very hard pressed to find any 2
consistency in our current regulations. So, thank you 3
very much.
4 MEMBER BALLINGER: Thank you. Al?
5 MR. CSONTOS: Al Csontos, NEI, director of 6
fuels. And so, we were one of the ones that asked for 7
the extension. This is a very complicated rule 8
making. A lot of good questions that the NRC has 9
asked of the industry. We have a lot to discuss, a 10 lot of stakeholders wanting to discuss the various 11 aspects, as well as not only the legacy reactors, but 12 also maybe advanced reactors as well.
13 And so, this is a very complicated rule 14 making. And a lot of the questions that you're asking 15 here, a lot of questions we're asking internally.
16 We're also going to specifically focus on timing. We 17 have strategic aspirations to move to two year fuel 18 cycles, as well as possibly power up rates, as you 19 were hearing earlier today. And so, the questions 20 though that are on the table for us is not just these 21 questions, but also when can we implement?
22 And what's reasonable to do in a time 23 period to implement achievable things, all of these 24 options. And so, as Joy was mentioning, we asked the 25 question of how can we provide a more holistic NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
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consideration of these options? And so, that was one 2
of the questions that the staff answered during the 3
public meeting last week. And so, just want to 4
mention that I think we heard some of the same 5
comments both at the subcommittee, and full committee.
6 And actually, you're asking the same 7
questions that we are as well. But you're going to 8
hear from us, hopefully we can get the extension, 9
you'll hear from us, I think a path that is timely to 10 what I think the commission wanted, as well as the 11 industry wanted to meet their aspirations. So, I 12 think just more on that later, but at this time just 13 want to give that feedback to you that this is 14 complicated.
15 And I guess don't assume that all the 16 options that are being thrown out there are going to 17 be one or another. As Joy said it's going to be more 18 a combination, and a little bit of column A, B, C, and 19 we're going to provide that in our response. Thank 20 you.
21 MEMBER BALLINGER: Thank you. I'll ask 22 one more time, are there any people out there that 23 would like to make a comment? Okay, hearing none, now 24 I'm not sure what the timing is, 11:30, we need to --
25 CHAIR REMPE: I think at this point we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
128 1
could go off the record.
2 MEMBER BALLINGER: That's what I was about 3
to say.
4 CHAIR REMPE: Okay, so then you want to 5
turn it back to me, and I will release the court 6
reporter for the entire meeting?
7 MEMBER BALLINGER: Okay.
8 CHAIR REMPE: Okay. So, thank you again 9
for your presentations, and court reporter, we are 10 done with your services for this entire meeting.
11 (Whereupon, the above-entitled matter went 12 off the record at 11:27 a.m.)
13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14TH ST., N.W., STE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
Regulatory Basis on Increased Enrichment of Conventional and Accident Tolerant Fuel Designs for Light-Water Reactors November 2, 2023
Opening Remarks Scott Krepel Branch Chief Division of Safety Systems
NRC Staff Presenters
- Philip Benavides, NMSS:
- Overview of Increased Enrichment Rulemaking
- Charley Peabody, NRR:
- Criticality Accident Requirements (10 CFR 50.68)
- Philip Benavides on behalf of Don Palmrose, NMSS:
- Environmental Regulations in 10 CFR 51.51 & 10 CFR 51.52
- Jason Piotter, NMSS:
- General Requirements for Fissile Material Packages (10 CFR 71.55)
- Elijah Dickson, NRR:
- Control Room Requirements (10 CFR 50.67 and GDC-19)
- Joseph Messina & Ashley Smith, NRR:
- Fuel Fragmentation, Relocation, and Dispersal
Overview of Increased Enrichment Rulemaking Philip Benavides Project Manager Reactor Rulemaking & Project Management Branch
Rulemaking Process Pre-Rulemaking:
Identify the need Regulatory Basis Proposed Rule Final Rule
-Scope
-Approach
-Resources
-Commission Engagement
-Public Meeting
-Technical, policy, and legal info.
-Cost and benefit
-Public Comment
-ACRS
-Regulatory Analysis
-Basis
-Public Meeting
-Public Comment
-ACRS
-CFR Change
-Responds to public comments
-Explains changes and basis Future ACRS Engagement
Issue Identification
- Regulatory Issue:
- Current licensing framework allows for the use of > 5 weight percent uranium-235; however, technology developments may require numerous exemptions to utilize fuel enriched above 5 weight percent uranium-235.
- Proposed Solution:
- Rulemaking would provide for a generically applicable standard informed by public input, providing consistent and transparent communication, rather than individual licensing requests as discussed in SECY-21-0109, Rulemaking Plan on Use of Increased Enrichment of Conventional and Accident Tolerant Fuel Designs for Light-Water Reactors.
- Commission Rulemaking Plan Approval:
- Staff request to the Commission to pursue rulemaking and develop a regulatory basis was approved by the Commission via SRM-SECY-21-0109 on 3/16/2022.
Status of Rulemaking Activity
- The NRC staff issued a regulatory basis on September 8, 2023
- Discusses regulatory issues and alternatives to resolve them
- Considers legal, policy, and technical issues
- Considers costs and benefits of each alternative
- Identifies the NRC staff's recommended alternative for most regulatory issues
- FFRD: Alternatives offered with no recommendation at this time
- ACRS Fuels, Materials, and Structures Subcommittee: October 18, 2023
- Stakeholder Involvement:
- Public Meetings held on June 22, 2022 & October 25, 2023
- Comment Period until November 22, 2023
- Proposed rule due to the Commission: December 2024
Regulatory Basis Topics
- The regulatory basis describes the evaluated technical topics:
- Criticality Accident Requirements (10 CFR 50.68)
- Uranium Fuel Cycle Environmental Data - Table S-3 (10 CFR 51.51)
- Environmental Effects of Transportation of Fuel and Waste - Table S-4 (10 CFR 51.52)
- General Requirements for Fissile Material Packages (10 CFR 71.55)
- Control Room Requirements (10 CFR 50.67 and GDC-19)
- Fuel Fragmentation, Relocation, and Dispersal
Criticality Accident Requirements of 10 CFR 50.68 Charley Peabody Nuclear Systems Performance NRR Increased Enrichment Regulatory Basis Topics
Criticality Accident Requirements of 10 CFR 50.68: Summary of Regulatory Issue
- Rule utilizes k-effective acceptance criteria with required probability and confidence levels to permit exemptions to 10 CFR 70.24 active criticality monitoring and emergency planning requirements
- Current rule limits application to enrichments of 5% weight Uranium-235 10
10 CFR 50.68: Recommended Alternative Staff Recommends Alternative 3: replacing the current enrichment limit with the Technical Specifications Design Feature limits
- Maintains existing subcriticality margins at the same k-effective probability and confidence levels
- Criticality safety impacts are addressed during the fuel transition license amendment request process
- Allows consideration of low-enriched uranium up to <20.0% weight
- Research Study with Oak Ridge National Laboratory
- Preserves the § 50.68(b) compliance for all existing fleet without backfit 11
Questions
Environmental Requirements of 10 CFR 51.51 & 51.52 Donald Palmrose Environmental Review New Reactors Branch NMSS Increased Enrichment Regulatory Basis Topics
Environmental Requirements of 10 CFR 51.51 & 51.52 Summary of Regulatory Issues
- The environmental data of Table S-3 (10 CFR 51.51(b)) and environmental impacts of Table S-4 (10 CFR 51.52(c)) are bounding for enrichments up to 5 wt % U-235.
- Currently no approved assessment of environmental impacts related to the uranium fuel cycle or transportation of fresh unirradiated fuel for increases greater than 5% U-235.
- NUREG-2266 is a draft report for comment that would support these tables to bound up to 8 wt % U-235
- Until further environmental evaluations are completed:
- For Table S-3, advanced reactor construction and operation licensing requests could involve use of up to 20% U-235 and require case-by-case reviews.
- For Table S-4, reactor licensing requests with shipments of fresh fuel with more than 5 wt % U-235, there would need to be a full description and detailed analysis of transportation impacts as directed by 10 CFR 51.52(b).
14
10 CFR 51.51 and 51.52: Alternatives
- 1. No Action - Maintain current regulatory framework by assessing environmental impacts from the uranium fuel cycle on a case-by-case site-specific basis
- 2. Rulemaking - Pursue the necessary environmental analysis to justify continued use of Table S-3 and Table S-4 for increased enrichment and then pursue rulemaking to modify both tables (recommended)
- 3. Rely on Revised or Updated Environmental Analysis - Rely on the updated analysis when reviewing licensing actions for the use of increased enrichment fuels 15
Questions
Packaging Requirements of 10 CFR 71.55 Jason Piotter Containment, Thermal, Chemical & Fire Protection Branch NMSS Increased Enrichment Regulatory Basis Topics
10 CFR 71.55: Options for seeking approval by Certificate of Compliance (1) Evaluate UF6 packages with optimum moderation § 71.55(b)
- current package design
- redesigned package (2) Request an exemption to § 71.55(b)
- Exceptions to § 71.55(b)
(3) Request approval under § 71.55(c) (Requires special design feature and adm. controls.)
(4) Request approval under § 71.55(g) (enrichment limited to 5 weight percent U-235) 18
10 CFR 71.55: Rulemaking Alternatives
- 1. No Action - Utilize Existing Certificate of Compliance Options
- 2. Rulemaking - Increase Enrichment limit to < 20.0% wt U-235
- 3. Rulemaking - Remove Enrichment Limit 19
10 CFR 71.55(g)(4): Recommended Alternative Staff Recommends Alternative 1: No Action
- To date, industry plans communicated to the NRC have not indicated that there would be enough requests for package approvals, for transporting UF6 enriched up to but less than 20.0 weight percent U-235, to conclude that rulemaking would be the most efficient or effective process to support package approvals.
- All alternatives are nearly cost neutral in terms of implementation;
- FRN Question
- Is there additional information that can be shared to augment comments made by the public in June 2022 regarding the need for rulemaking to support licensing new or existing UF6 transportation package designs?
20
Questions
Control Room Design Criterion of 10 CFR 50.67 and GDC-19 Elijah Dickson Radiation Protection and Consequence Branch NRR Increased Enrichment Regulatory Basis Topics
Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Summary of Regulatory Issue
- The history of fuel utilization for the current large light-water fleet has seen a gradual progression toward higher fuel discharge burnups and increased enrichments.
- In general, there has been enough margin in the facilities design bases to accommodate the criterion even for power uprates of up to 120 percent of the originally licensed steady-state thermal power level.
- The NRC recognizes the challenges that licensees face to retain margin for operational flexibilities within their licensing basis and the small amount of margin to the control room design criterion itself.
- The NRC does not want to unnecessarily penalize licensees for seeking increased enrichments that may then result in margin reductions and thereby requiring licensees to perform potentially extensive analyses to demonstrate compliance without a commensurate increase in safety.
23
Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Background - 1/2
- Objective: ensure the design of the control room and its habitability systems provide for a habitable environment allowing the operators to remain in the control room and not evacuate during an emergency. Ideally, the environment should be a short-sleeved, comfortable environment for the control room operators. Such an environment was perceived to facilitate operator response to normal and accident conditions.
- History: developed in the 1970s and amended in the 1990s, the criterion did not foresee how licensees currently operate their facilities and manage their fuel, consider fuel enrichments above 5 weight percent U-235, or maintain coherence with other regulations concerning the Commission's comprehensive radiation protection framework.
- Intent (Statements of Consideration for 10 CFR 50.67): the control room criterion does not imply that this would be an acceptable exposure during emergency conditions, or that other radiation protection standards of Part 20, including individual organ dose limits, might not apply. This criterion is provided only to assess the acceptability of design provisions for protecting control room operators under postulated DBA conditions.
24
Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Background - 2/2
- Note: While the design criteria are computed in terms of dose, they are figures of merit used to characterize the minimum necessary design, fabrication, construction, testing, and performance of the requirements for SSCs that are important to safety. They do not represent actual occupational exposures received during normal and emergency conditions, which are primarily controlled by 10 CFR Part 20, Standards for Protection Against Radiation.
- Consider modifying the control design criteria to a higher, but still safe performance level; changes would not alter normal operational and emergency exposure limits controlled under 10 CFR Parts 20 and 10 CFR 50.47.
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Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Radiation Protection Regulatory Framework
- In 10 CFR Part 20, the NRC applies these standards to all exposure situationsnormal and emergency conditionsbut also provides an explicit exemption for cases in which compliance would limit actions that may be necessary to protect health and safety.
- To provide reasonable assurance that adequate protective measures can and would be taken in a radiological emergency, the NRC has established emergency planning regulations in Appendix E, Emergency Planning and Preparedness for Production and Utilization Facilities, to 10 CFR Part 50 and planning standards for nuclear power reactors in 10 CFR 50.47, Emergency plans.
- The Emergency Plans provides additional regulatory provisions to bear on the control of occupational exposures during emergencies. Paraphrased from Section 50.47.(b).(11) provides the following:
Where the means for controlling radiological exposures shall include exposure guidelines consistent with EPA Emergency Worker and Lifesaving Activity Protective Action Guides.
- The guidelines for actions to protect valuable property is 10 rem where a lower dose is not practicable, the guidelines for actions to save a life or to protect large populations is 25 rem. These guidelines endorsed in Section 50.47.(b).(11) is consistent with the position of 20.1001.(b).
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Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Alternative 1
- No Action - Maintain the current regulatory framework
- Continue to revise existing guidance with updated source terms when data become available and update transport models on an ad hoc basis as research and resources become available.
- Plan to issue RG 1.183 Rev 2 in FY 2025.
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Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Alternative 2
- Pursue Rulemaking to Amend the Control Room Design Criteria and Update the Current Regulatory Guidance Accordingly with Revised Assumptions and Models and Continue to Maintain Appropriate and Prudent Safety Margins
- Assess and identify a range of acceptable values based on sound regulatory and scientific recommendations.
- Initiate new research and analyses for mechanistic transport models and re-baseline other several operational and human health assumptions
- Plan to issue RG 1.183 Rev 2 in support of the amended control room design criteria.
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Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Alternative 3
- Update the Current Regulatory Guidance with Revised Assumptions and Models and Continue to Maintain Appropriate and Prudent Safety Margins
- Initiate new research and analyses for mechanistic transport models and re-baseline other several operational and human health assumptions AND assess other mathematical methods, computational-and statistical approaches to reduce unnecessary conservatism and provide greater flexibility.
- Plan to commence work on RG 1.183 Rev 3 based on new research and analyses soon after RG 1.183 Rev 2 is issued.
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Control Room Design Criterion of 10 CFR 50.67 and GDC-19:
Recommended Alternative Staff recommends Alternative 2: Pursue rulemaking to amend the Control Room Design Criteria and update the current regulatory guidance accordingly with revised assumptions and models and continue to maintain appropriate and prudent safety margins 30
Questions
Fuel Dispersal Joseph Messina Ashley Smith Nuclear Methods and Fuel Analysis NRR Increased Enrichment Regulatory Basis Topics
Fuel Fragmentation, Relocation, and Dispersal (FFRD)
- At HBU experiments have shown that the fuel can fragment during a LOCA
- Differences in pressure across the cladding can lead to cladding ballooning and burst
- The fragmented fuel can relocate axially into the balloon region of the fuel rod and if burst occurs, disperse into the RCS 33
FFRD: History 34 1974 -
10 CFR 50.46 criteria for LOCAs 1980 -
FFRD Discovered 1984-1995
- GI-92, Fuel Crumbling During LOCA 2006 -
FFRD testing showed gross fuel loss at high BU 2008 -
RIL-0801 2012 -
NUREG-2121 2015 -
SECY 0148 - No imminent safety concern 2016 -
Draft final rule for 50.46c 2021 -
RIL-2021-13 2022 - SRM-SECY 0109 -
Include FFRD in IE Rulemaking 2024 - Fuel Dispersal PIRT to be conducted
Fuel Dispersal: Background and Regulatory Issue
- The 50.46 acceptance criteria date to 1974 when FFRD were not known phenomena
- Acceptable approaches to demonstrate compliance with the regulations have ensured that catastrophic failure of the fuel rod structure and loss of fuel bundle configuration are precluded
- Fuel dispersal would be a departure of precedent
- Fuel dispersal is not explicitly addressed within the current regulations 35
Fuel Dispersal: Alternatives
- The NRC staff have developed 5 licensing pathways that could be pursued as a part of IE rulemaking
- Alternatives should be seen as mutually inclusive (i.e., combinations of elements from multiple alternatives could be considered)
- NRC staff may consider other approaches based on public comments 36
Fuel Dispersal Alternative 1
- No action
- No major updates to regulatory framework
- Apply existing regulations for treatment of dispersal
- Licensees could show that rods susceptible to fine fragmentation would not rupture to demonstrate compliance
- Consideration of significant fuel dispersal without any major regulatory updates challenges and regulatory uncertainty
- Licensing pathways considering significant dispersal are discussed as part of other alternatives 37
Fuel Dispersal Alternative 2
- 50.46a-style modification of ECCS requirements
- 50.46a was a draft final rule in 2010 that proposed to establish a transition break size (TBS), above which LOCAs can be analyzed with more realistic assumptions
- Best-estimate modeling and more realistic assumptions may help to demonstrate that no rods susceptible to dispersal would burst
- May impact Increased Enrichment rulemaking schedule 38
Fuel Dispersal Alternative 3
- Safety demonstration for post-FFRD consequences
- Criticality, coolability, dose, long-term cooling, etc. should be addressed like any other LOCA phenomena
- Guidance would be issued with the rule, which could be updated to include more specific guidance after more research is performed
- Current state-of-knowledge may lead to conservative guidance, but research could be performed in the long term to relax guidance
- May impact Increased Enrichment rulemaking schedule 39
Fuel Dispersal Alternative 4
- Generic bounding assessment of dose and use risk insights for post-FFRD consequences
- Dose criterion for LOCA with fuel dispersal would be established
- Licensees would demonstrate ability to predict a fuel dispersal source term or be directed to use a fraction of the MHA-LOCA source term based on the amount of predicted fuel dispersal.
- Downstream effects of dispersal could be treated as beyond design basis consequences and addressed with risk insights
- E.g., insights from operating experience and other regulatory requirements, programs, and industry initiatives
- May impact Increased Enrichment rulemaking schedule 40
Fuel Dispersal: Alternative 5
- Probabilistic fracture mechanics to show that leaks in large pipes will be identified before failure, precluding the need to analyze LBLOCAs
- E.g., leak-before-break and xLPR
- Derived from industry initiatives
- Licensees could use LBB to demonstrate that RCS leaks could be detected and operator action taken before a pipe breaks for a postulated LBLOCA, thus precluding a LBLOCA and fuel failure.
- May impact Increased Enrichment rulemaking schedule 41
Fuel Dispersal: Recommended Alternative Staff Has No Recommendation at this time
- The staff has determined that additional stakeholder input is required before finalizing a recommendation.
- 6 questions are posed to the public in the FRN regarding fuel dispersal to better understand stakeholder perspectives.
- The staff will review the stakeholder input on fuel dispersal to determine the path forward during the proposed rule.
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Fuel Dispersal: Alternatives
- Alternative 1: No action.
- Alternative 2: 50.46a-style modification of ECCS requirements.
- Alternative 3: Perform a safety demonstration for post-FFRD consequences.
- Alternative 4: Provide a generic bounding assessment of dose and use risk insights for post-FFRD consequences.
- Alternative 5: Use probabilistic fracture mechanics to show that leaks in large pipes will be identified before failure, precluding the need to analyze LBLOCAs.
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Questions