ML23171B031
| ML23171B031 | |
| Person / Time | |
|---|---|
| Issue date: | 06/09/2023 |
| From: | NRC/OCM |
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| Shared Package | |
| ML23110A698 | List: |
| References | |
| M230609 | |
| Download: ML23171B031 (63) | |
Text
1 UNITED STATES NUCLEAR REGULATORY COMMISSION
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MEETING WITH ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
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- FRIDAY, JUNE 9, 2023
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The Commission met in the Commissioners' Hearing Room, at 10:00 a.m., Christopher T. Hanson, Chair, presiding.
COMMISSION MEMBERS:
CHRISTOPHER T. HANSON, Chair JEFF BARAN, Commissioner DAVID A. WRIGHT, Commissioner ANNIE CAPUTO, Commissioner BRADLEY R. CROWELL, Commissioner ALSO PRESENT:
BROOKE P. CLARK, Secretary of the Commission MARIAN ZOBLER, General Counsel ACRS MEMBERS PRESENT:
2 JOY REMPE, Chairman, Advisory Committee on Reactor Safeguards (ACRS)
RON BALLINGER, Member, ACRS VICKI BIER, Member, ACRS WALT KIRCHNER, Vice Chair, ACRS DAVID PETTI, Member-at-Large, ACRS
3 P R O C E E D I N G S 1
10:00 a.m.
2 CHAIR HANSON: Good morning, everyone, and happy 3
Friday. I convene the Nuclear Regulatory Commission's public meeting for the 4
purposes of hearing from members of the NRC's independent Advisory 5
Committee on Reactor Safeguards, or ACRS, on issues recently reviewed by 6
the Committee.
7 Welcome, everyone. And welcome to Commissioner Caputo, 8
too. She's online with us, and will be joining us via Teams this morning, and 9
look forward to her questions.
10 The ACRS plays an important role in the statutory structure of 11 the NRC. It's intended to be a built-in review body with significant discretion 12 and independence. This independence is even more important for new reactor 13 reviews that will include significant novel considerations and issues associated 14 with new technologies. Feedback from the ACRS is going to be critical.
15 That's why I'm glad to see the addition of Dr. Martin.
16 Welcome, Dr. Martin. He brings significant experience over 30 years in nuclear 17 reactor safety, and most recently as a technical consultant, I believe, for BWX 18 Technologies. You have significant experience in accident analysis 19 methodologies and code development support, and we look forward to your 20 contributions. Thank you.
21 I also want to acknowledge up-front the Committee's good 22 work recently, and value-add in the recent review of fusion regulatory options, 23 and also identifying issues such as the density wave oscillation and the boron 24
4 redistribution issues with the NuScale design. So, thank you for that. We're 1
going to be hearing from our ACRS panelists on a number of interesting topics 2
to include both NuScale and Kairos and others, and Part 53's.
3 But before we get rolling with those presentations, I'll ask my 4
colleagues if they have any remarks they'd like to make.
5 (Pause.)
6 CHAIR HANSON: Okay, with that, Dr. Rempe, I'll hand it over 7
to you.
8 DR. REMPE: Thank you, Chair Hanson, and good morning, 9
Chair Hanson and the Commissioners. The ACRS does appreciate the 10 opportunity to meet with you. Slide two shows the agenda for this briefing.
11 There'll be five presentations, after my overview we'll hear from Member 12 Ballinger about the SHINE medical isotopes operating license application, 13 followed by Member Kirchner on the NuScale topical report for the emergency 14 planning zone site boundary associated with the plume exposure pathway. And 15 finally, Member Petti will provide an overview of our reports on the Part 53 16 rulemaking, and the Kairos Hermes construction permit application.
17 Since our last briefing with you, which was in June, 2022, 18 we've issued 17 letter reports. Four of these reports pertaining to fusion energy 19 system regulation in the Part 53 rulemaking package. Slide four lists the letter 20 reports we've issued pertaining to submittals for design centered application.
21 Our review of the SHINE, and the Kairos applications applied 22 an approach that we first applied in the phase four NuScale ECA application, as 23 you may recall. The staff of the ACRS along with NRR staff worked together to 24
5 implement this evolving report. The lead member will assign members with 1
relevant expertise a particular topic, or chapters to review, and they report back 2
to the Committee, and as needed risk important topics are scheduled for 3
briefing.
4 Although this does reduce the number of meetings required, 5
as well as the number of briefings from the applicant, and the staff, we believe it 6
does not adversely affect our safety mission. As you may recall, during the 7
phase four review, we identified issues such as the boron dilution issue that led 8
to changes in the design, as well as instrumentation set point settings.
9 The approach does offer the ability for reductions in the 10 schedule for the review. For example, our review of the Kairos Hermes 11 application was completed last month, four months ahead of our scheduled due 12 date with NRR, and yet, as you'll hear today from Member Petti, we still were 13 able to identify several significant safety considerations that were not present in 14 the initial application, or in the draft SC that we reviewed from the staff.
15 Slide five lists reports that pertain to the LWR operating fleet.
16 These reports address topics related to digital I&C, new fuel types for PWRs, 17 water sources for recirculation cooling, and a subsequent license renewal 18 application. In the case of the Oconee SLR application, there were no findings 19 in the staff review, or open items, or confirmatory items in the staff review.
20 So, we applied a streamlined approach that only required 21 briefings from the staff, and the applicant in a single meeting. The last letter 22 report was actually a one paragraph transmittal letter for a white paper that our 23 senior technical advisor prepared, regarding Dr. Hossein Nourbakhsh, to be 24
6 prepared regarding historical, as well as recent contributions from ACRS during 1
our reviews.
2 I asked Dr. Nourbakhsh to provide this white paper as a 3
knowledge transfer effort to new members, and other interested stakeholders, 4
and I think that it has some very significant findings. In the next slide I wanted 5
to highlight some other ongoing review activities. As indicated in the first bullet, 6
we have initiated interactions regarding several design center applications.
7 As you may recall, during our June 2022 briefing, I mentioned 8
that the ACRS reorganized in January 2022, and we assigned a lead ACRS 9
staff member to be associated with each of these applications, as well as other 10 applications we anticipate for the first year. That lead member, along with an 11 ACRS staff member hold informal meetings periodically with the NRR staff so 12 they remain cognizant of the progress of that application.
13 And they report back to the ACRS, and we schedule meetings 14 as appropriate on what topics we believe will be important with respect to risk, 15 and safety significance. Ultimately as more of these applications as well as 16 others transition from the pre-application stage to the application stage, we 17 envision that we will again divide ACRS up into two teams as we did back 18 during the nuclear renaissance era around 2010, or 2011 so that we can still 19 accomplish our mission without adversely affecting schedule.
20 And the last two slides, I'd like to discuss some other ongoing 21 ACRS activities. And as in prior briefings, I'll start with our continuing efforts to 22 transform, or initiate process improvements. In addition to knowledge transfer, 23 we are starting to develop, or continuing to develop guidance that promote best 24
7 practices for ACRS on conduct of subcommittee meetings on letter writings.
1 And most recently, we're starting to develop best practices for 2
conducting design centered reviews. And we believe that this facilitates 3
communicating not only us scheduling, and emphasizing what's risk important, 4
but also in communicating to NRR staff on what our plans are for the reviews.
5 We are continuing -- it'd be good to see the slide for a minute -- other activities, 6
such as -- I'm sorry, the prior slide, please.
7 We are continuing other activities to streamline, and focus our 8
reviews on risk significant items. For example, in recent times, you may have 9
noticed that instead of letter reports, we're emphasizing our findings in 10 paragraphs that are provided in our meeting summary reports, because we find 11 it's more important to focus on those letters that are risk significant.
12 And then in the last slide, we are continuing other beneficial 13 activities. We continue to hear from the staff on their transformation efforts, and 14 provide comments as appropriate. We are resuming our visits to plant sites, as 15 well as fuel fabrication facilities. Last summer we visited region three, the 16 Byron plant, as well as the SHINE construction plant.
17 We find that these visits are extremely important, because 18 they help us better understand the health of the facility, as well as interacting 19 with the staff, so that we can better understand their concerns, and priorities.
20 And at last. Oh, I also wanted to mention too that in addition to our knowledge 21 transfer, our reorganization, and revising our approaches for conducting our 22 reviews, we're also looking at to make sure that we have adequate expertise in 23 our membership.
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8 So, we do appreciate your efforts to help us bring Dr. Martin 1
on board. And then last, I did want to mention briefly that we did complete our 2
international activity with representatives from advisory committees that support 3
regulatory agencies in Finland, France, Japan, and the United Kingdom. At this 4
time we are in the process of compiling a report that includes the presentation 5
materials.
6 As well as summarizing some of the discussion topics, and 7
key findings from that interaction. And that completes my planned remarks, and 8
I'd like to ask Member Ballinger to begin his presentation.
9 DR. BALLINGER: Thank you, Chairman Rempe, and good 10 morning, folks. First slide, please. I'm going to give a discussion of the SHINE 11 application review. The SHINE submitted an application in 2019, middle of 12 July, and they asked for 30 year license, and we completed the review in 13 December 2022 using roughly the same format that Chairman Rempe has 14 described. Next slide. please.
15 With regard to the facility characteristics, the facility is 16 designed to produce moly-99, which I'm sure many people in here know that if 17 you're over 65, or have had heart surgery, present company included, 18 technetium-99 is very important for the national medical infrastructure. So, it's 19 produced, again, from fission produced moly-99, which in this case is actually 20 fusion fission produced moly-99 from accelerators.
21 Which is probably the first instance of actually generating 22 fusion power, hopefully not the last. And the production facility consists of this 23 irradiation facility, plus an extraction facility, it's a two component system where 24
9 the moly-99 is separated from the fission products. Next slide. The SHINE's 1
unit, the SHINE facility has a lot of safety features which make it both safe, and 2
unique, if you will.
3 Low power density irradiation units accelerators, automatic 4
shutdown of the irradiation process, they're accelerators that can just be turned 5
off. And criticality is avoided, or not only avoided, but excluded during 6
dissolving filling on the radiation side, and criticality safe vessels are used for 7
the entire facility, as well as engineering design features.
8 Next slide. So, as part of this process, we had a number of 9
subcommittee meetings, six to be exact. We had several 19 chapter topic 10 memos as Chairman Rempe has described, and we had a site visit in 11 Janesville. Chairman Rempe has emphasized the importance of these visits.
12 This visit was for me, very important, because first off, this is kind of a one off 13 facility, it's unique.
14 It's the first time we've been to visit one of these things, and 15 we get to talk to people that were both actually the president of the company, 16 plus the lead design engineer, and the lead technical person, that's the way I 17 would describe them. And you get a really good feeling about these guys 18 having a good handle on their topic, and on their design.
19 So, I can't more emphasize the fact that these site visits are 20 very important. Next slide. By way of the safety analysis approach, the SHINE 21 people used what's called a maximum hypothetical accident. What they 22 basically did was to do a failure modes and effect analysis to identify every 23 scenario that could cause an accident, then use that analysis to define a design 24
10 basis accident, and then deal with that.
1 So, that was their process, and it worked quite well. Next 2
slide. As part of our review, again, visiting the site was very important. We 3
realize the importance of human factors in the facility. This is going to be a 4
facility where there's a lot of repetitive things going on, and so there's often 5
times a problem with repetitive action where you get kind of complacent.
6 So, we needed to understand that process. The coordination 7
with the community was also very important, because there's an airport that's 8
within walking distance of the site, and the site is going to make use of fire 9
departments, local organizations, and they really need to have a very good 10 understanding of what they're dealing with if there's a need for their service.
11 And last, but not least, there's an increasing importance of 12 cybersecurity, and so we got a chance to talk to them about that. But that is 13 considered to be important. Next slide. Based on our analysis, and our visits, 14 and the like, we concluded that the operating license should be issued. Next 15 slide. Okay, some lessons learned.
16 Again, as I keep reciting this, but it's true, as Chairman 17 Rempe has emphasized, the grouping of these chapters requires close 18 coordination between us, the staff, and the applicant to make sure that we don't 19 have a situation where there's kind of bleed off into other areas that we haven't 20 discussed beforehand. So, it's important to coordinate things very well that way.
21 And that, also the importance of sequencing the review with 22 no open items. We haven't emphasized that in the past, but this is a case 23 where we've had no open items, and that puts the burden both on us, and on 24
11 the staff to make sure there's no open items. In the old approach, there were 1
open items, and that kind of allowed for a little bit of slack in the system, but not 2
so in this case.
3 That required, again, committee flexibility. We had to sort of 4
adjust things on the fly, which we succeeded at, and this idea of having 5
individual members conduct a detailed review, and then have a discussion with 6
the overall Committee, that is not new, we started that with NuScale, but we 7
advanced that with this thing, with this analysis, and that's proven to be very 8
important.
9 Next. I think that's about it. That sure is about it. So, I will 10 turn over the presentation to Walt Kirchner.
11 DR. KIRCHNER: Thank you, Ron. Good morning, I'm going 12 to talk to you about our review of the NuScale methodology for establishing 13 EPZs, emergency planning zones, for NuScale SMR plants.
14 Next slide, please. So, I think this is common knowledge 15 background. Generally, EPZ sizes for nuclear power plants are defined by a 16 plume exposure pathway, and that's roughly ten miles in radius, and an 17 ingestion pathway area of about 50 miles in radius.
18 The basis for this was developed back in the 70s in a NUREG 19 report 0396, and its primary objective was to provide guidance for citing, and 20 development of emergency plans at then existing plants, and future plants, 21 such as to produce dose savings for a spectrum of accidents that might result in 22 exposure in excess of the protective action guidelines.
23 Next slide, please. So, there's an appendix to NUREG-0396 24
12 that outlines basically the rationale that was used to come up with this generic 1
ten-mile radius, and that was a -- I'll choose my words carefully here. Again, 2
we're talking about a generic ten-mile radius, and basically they recognized the 3
need for establishing defense-in-depth, because that's when emergency 4
planning is your last line of defense.
5 And in doing this they looked at a spectrum of accidents for 6
the operating fleet at the time, and then they made use of the analysis in 7
WASH-1400, which was just completed a couple of years earlier to look at 8
severe accident sequences as well.
9 Next slide, please. So, we have existing provisions in the 10 regulations for the plants, and we also have an exception, so to speak that 11 allows for a case by case basis for setting the EPZ for gas cooled reactors.
12 As well as reactors less than 250 megawatts thermal, what 13 we're calling SMRs in current parlance. Since that time, '78, when this was 14 done, there have been really significant advances both in the knowledge base, 15 the code methods that we use, and of course, unfortunately post Fukushima, 16 the actions that came out of that, as well as the SOARCA study, that's the State 17 of New York Reactor Consequences Analysis.
18 And so this concept, the concept that I'm going to talk about 19 now in more detail of looking at sizing an EPZ based on consequences of dose, 20 and then correlating a distance with the dose, such as to meet the protective 21 action guidelines, was explored by your staff, and that was documented in 22 SECY-11-0152. The industry picked up on that, and NEI developed a white 23 paper in the following year that also examined this.
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13 And some of the things that were recommended in the 1
industry white paper are interesting here. That you would use the plant specific 2
PRA to inform the analysis, and that you would also supplement this with an 3
operationally functioned mitigation capability, which most of the plants post-9/11 4
have installed.
5 Next slide, please. I'll go more now to the NuScale 6
methodology. Again, it follows the same basic approach that was used in 0396.
7 It requires a full-scope PRA that meets the current standards, and looks at both 8
internal and external events, and all modes of operation. So, all modes, in my 9
parlance, is a euphemism for spent fuel pools and other aspects of plant safety.
10 They take advantage of RELAP and MELCOR tools to 11 develop their source term, and then they use the MELCOR MACCS code for 12 the actual consequence analysis. So, the MACCS code basically does the 13 atmospheric dispersion, estimates the doses, and you can go through a number 14 of sequences with that, and develop a family of dose exposure curves. The 15 approach is very similar to what we reviewed for the Clinch River Early Site 16 Permit. And it meets the intent of SECY-20-0045, and the draft rule for SMRs.
17 Next slide, please. Okay, so the criteria that are used, you do 18 these analyses, and the criteria that is used to actually set that distance for the 19 plume exposure pathway is based on three checks, if you will, and these are all 20 conservatively implemented by NuScale. You first look at your design basis 21 source term, and do your analysis, do that release.
22 And then look at what that distance is to an exposure of 23 essentially one rem total equivalent dose exposure. Then you subsequently 24
14 look at less severe accidents. So, usually what we're talking about is for LWR 1
system, the containment is intact, and you look at a sequence of accidents 2
there. Again, using this PAG criterion of one rem, and you'll come up with a set 3
of distance versus dose results as well.
4 And then for the more severe accidents, now, at least for 5
LWR technologies, we're looking at containment bypass or failure, you then 6
look at an acute body dose of 200 rem. And when you complete these 7
analyses, effectively, it's that last criterion that sets the plume exposure 8
pathway, and hence the EPZ size analysis.
9 So, in the case of NuScale, they also looked at multi-module 10 effects, where you're concerned about common cause initiating events for the 11 modules, as well as where the systems are connected.
12 So, that analysis was also done to take into account the multi-13 module aspects of the NuScale design. The staff did an excellent job in 14 reviewing this, a very thorough job, and there were several conditions put on 15 the application of the NuScale TR methodology. NuScale used a proprietary 16 screening threshold for seismic events. Now, for this design, it's likely that a 17 seismic initiator is going to be the dominant contributor to the risk profile.
18 So, the staff, when they completed their review, they put 19 several conditions, limitations on the use of the TR. The first was they limit the 20 screening threshold to sites where ground motion response spectrum is 21 bounded by NuScale certified seismic design response spectrum, this just 22 makes good sense by the way. And then secondly, they limit the seismic event 23 screening threshold to the NuScale's high confidence of the low probability of 24
15 failure for plant level fragilities, so called HCLPF.
1 And when this TR is used at an actual site, then they will 2
require that the COL applicant do a confirmation that the ground motion 3
response spectrum, and HCLPF plant level fragility limits for that site are 4
confirmed for the as built plant.
5 Next slide, please. So, in summary, this NuScale 6
methodology is certainly technically sound, and I would add, conservative in its 7
approach, and its application.
8 The staff's evaluation as I mentioned previously, was quite 9
good, and they explored things like cliff edge effects, which is something one is 10 concerned about when you're looking at seismic analysis of power plants. And 11 we felt that the staff should preserve the insights gained from this exercise, and 12 use that in other applications, where again, the seismic aspect of the accident 13 spectrum may be the dominant contributor to risk.
14 We look forward, and plan to review an initial application of 15 the TR for an actual site, and I'll just summarize by saying that prudent 16 emergency planning, and preparedness will still require the staff looking at each 17 applicant on a case by case basis. And especially when we get to advanced 18 reactors, we're going to have different technologies, you're going to have 19 different hazards.
20 So, it's not like this is just turn the crank, here's a number, 21 you've got an EPZ. There are a lot of considerations that go into that kind of 22 analysis, and what comes with that too is that you're looking for on site, and off 23 site emergency plans that can deal with the hazards that the technology 24
16 presents.
1 And I will note, just one footnote to this summary is that going 2
back to the NEI white paper from 2013, they recommended to address 3
uncertainties, and the potential lack of completeness in the PRA, especially for 4
a new design, where we don't have the operating experience that we have with 5
the current fleet, that the emergency planning provide for expansion of the 6
existing emergency response plans beyond the EPZ boundary.
7 And that's just, in my mind, I think a prudent extension of this 8
methodology. And with that, I'll turn to my colleague Dave Petti.
9 DR. PETTI: Thank you, Walt. So, I'll first start by talking 10 about Part 53. In terms of background, as you well know, there are two 11 frameworks. Framework A builds on the industry DOE sponsored licensing 12 modernization project. Framework B resulted from industry comments for the 13 need for a more traditional deterministic approach to align with other 14 international approach like the IAEA's approach.
15 An important consideration that I'm sure we'll get to when we 16 get to Q&A, at least in my mind, is that any approach needed to demonstrate an 17 equivalent level of safety with what we have today, Part 50 and 52. I will go 18 through, there's two letters we wrote on this since we last met. The scope is, of 19 course as you know, incredibly vast. I'm going to focus largely on the last letter, 20 and the staff responses.
21 And how they responded, it's in blue text to help. I will not talk 22 about the reg guides that we reviewed with the final package in December, just 23 given the limited time that we have today.
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17 Next slide, please. So, in terms of findings, and 1
recommendations, we thought that the rule package, and the associated 2
guidance were adequate to solicit public comments.
3 We found framework A to be a valuable, logical framework.
4 It's a flexible, technology inclusive, performance based regulatory pathway for 5
both LWS, and non-LWS. It is risk informed, it's consistent with LMP, and in the 6
vernacular, you'll hear PRA in a leading role. Next slide. Framework B we felt 7
was newer, and still evolving, and significant changes could still occur, and they 8
did from our letter last July, I think, and in December.
9 There were substantive improvements over previous drafts.
10 They took a risk informed performance based approach for siting, and for 11 seismic design criteria, and seismic design, and that's a big cost driver, and 12 doing that in a risk informed way is going to be really helpful for folks that have 13 to design the plants. There are technology inclusive requirements for fire 14 protection in the additional licensing basis events, sometimes called the beyond 15 design basis events.
16 There is now a lot more common language with framework A 17 on human factors engineering, staffing, operator licensing, and training, so all 18 good improvements we thought. Next slide. With the package that we 19 reviewed, it starts with the December letter, there was the preamble, formally 20 known as the statements consideration. We felt important to talk about it, 21 because it really gives you the rationale behind the frameworks.
22 Without it, you just can't understand the depth, what's really 23 going on, and why things are the way they are. It provided at least to me, a 24
18 much clearer understanding of the depths, and the differences of the two 1
frameworks. There were people talking about how to combine, A, and B are 2
two different philosophies essentially, they're like oil, and water, they really don't 3
mix.
4 We had that same argument when we first started, well why 5
can't you combine them? It's when you read that preamble that it just jumps out 6
at you about how different they really are fundamentally. It gave valuable 7
context relative to assuring that a technology inclusive, performance based 8
framework that is framework A yields the comparable level of safety to the 9
existing regulatory requirements.
10 Next slide. So, the preamble spent some time talking about 11 this evaluation of equivalent level of safety for framework A. Framework B is 12 just what we have in a technology neutral mode, but it was different enough that 13 they felt they needed to do this. They noted that it's very similar to the 14 integrated assessment of plant risk using principles of integrated risk informed 15 decision making found in Reg Guide 1.174.
16 All the requirements in framework A were cross walked 17 against the existing set of requirements to make sure there were no gaps, or 18 holes, and then industry performed tabletop studies on a variety of advanced 19 reactor designs. They did gas, they did sodium, they did heat pipe, and a 20 molten salt one was done, it may not have been part of the official study, but I 21 remember reading a report, they looked at it.
22 I think the results indicated the approach is flexible, and 23 workable, it didn't set a higher regulatory bar for safety, and it showed a way to 24
19 incorporate risk insights into the design, and the regulatory review.
1 Next slide. In terms of AERI, the alternative evaluation for 2
risk insights, we really liked it. We had made an earlier comment about a 3
graded PRA/risk approach should be considered, typically in light of 4
microreactors, and I think that's really what AERI is about. So, we liked it so 5
much, we said, gee, it would be nice if it could be made available under 50 and 6
52, like the LMP is available today under 50 and 52, that was sort of the 7
thinking.
8 We also recommended a tabletop exercise should be 9
performed, that was sort of a recommendation for industry, obviously, and us in 10 tabletops. The language was a little unclear on this term self-reliant mitigation 11 facility, which is really important for how involved the reactor operator is to 12 execute a safety function, or not, and it needed to be somewhat more 13 consistent with the interrelationship with AERI, there was just some wording.
14 And the staff did improve the definition, and clarified that the 15 entry conditions, and the need for operator action were separate concepts, so 16 that was good. The next slide we made a comment that the rules should 17 explicitly mention that there will always be a human being maintaining oversight 18 of the reactor, providing a last line of defense independent of the design 19 features.
20 And the staff stated in the reconciliation letter that 21 performance based demonstrations, and prescriptive minimum requirements 22 would serve to ensure that there's always operating staff overseeing facilities.
23 Next slide. We made a comment on the discussion of defense-in-depth. It 24
20 should be amplified to address more explicitly what's the role of inherent, and 1
passive characteristics in accident prevention, and mitigation.
2 There is a difference in the balance between accident 3
prevention, and mitigation with the existing fleet versus non-light water reactors.
4 There's much more in the accident prevention camp. So, how does that evolve 5
in your thinking, and how defense-in-depth is thought about in the entire 6
approaches, because it's a lot, it's through all of our regulatory fabric.
7 And again, these safety characteristics, these inherent, and 8
passive characteristics may have to be relied upon in combination with 9
engineering, judgement, and data from the robust startup program to really 10 compensate for the lack of operating experience. Staff agreed with this 11 recommendation, and they anticipate some guidance. So, that's good, I think 12 that will really help here.
13 Next, there was improved discussion of safety functions, 14 they're very explicit in the top down approach of framework A. But in framework 15 B they're implicit through the safety design criteria, and the staff told us they 16 anticipate changing Reg Guide 1.232 to align the design criteria to the relevant 17 safety functions for framework B. So, that logical flow that you see in A will also 18 be available in B, and I think that'll help clarify things.
19 We commented, I think more than once on trying to 20 streamline the rule. Although it is shorter that Part 50, or 52 individually, it may 21 still be too long relative to expectations of stakeholders, and there is this trade-22 off between clarity and overall rule length that we've heard about from many.
23 And the staff continues to look for areas to streamline, and they did in 24
21 framework B, streamline some things in the last draft that we had seen.
1 Next slide, additional recommendations here. Manufacturing 2
licenses, there's large changes in the rule language here, a new licensing 3
pathway obviously for some of the microreactor designs, but we felt at this point 4
to make sure to exercise some prudence while more experience is gained.
5 This is something we just don't do on a routine basis.
6 In terms of the facility safety program, we liked that it was 7
going to improve the efficiency of NRC's licensing, and reactor oversight 8
programs at the individual facility level, and should consider its use in B, as well 9
as A. The integrity assessment program, this is words about looking for 10 degradation of SSCs, building, and life, especially in view of the experience in 11 the light water fleet.
12 Where water seemed like it was not going to be very difficult, 13 and it's turned out to be a pretty difficult coolant to make sure you don't get 14 stress corrosion cracking, and the like. And now you've got these new 15 coolants, and so we thought that that was a valuable program to add to Part 53, 16 recognizing that there are things like section 11 of the ASME code, I'm sure 17 there'll be good guidance to make sure there's no overlaps, and duplications.
18 Next, safety classification. We reiterated in our letter, 19 because it was in a previous letter, we're concerned the historical process of 20 classification resulted really in too many systems being classified as important 21 to safety, but later found when you had the PRA, to not have major risk 22 significance. So, our goal was really to try to optimize the safety footprint in the 23 design.
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22 And this would have major benefits for both the licensee, and 1
the regulator, keeping the focus on the risk significant components, particularly 2
with the new technology, where you don't know is that important, is that 3
important, or is this more important than that? You just don't know with the little 4
operating experience, and the staff agreed with the concept, and felt that the 5
classification systems were adequate.
6 Next is the concept of generally licensed reactor operators.
7 Lots of engagement on this, went through a lot of iterations, but we generally 8
now support the concept where there's a certain adequate level of qualification 9
for different types of facilities, depending on what the role is of the operator.
10 The staff improved the clarity of the definitions, and the tie between that self 11 mitigation facility definition, and the GLRO.
12 But looking ahead, we felt it's important for both the licensee, 13 and the GLRO to realize the weight of the certification decision. In the current 14 fleet, it is a big deal. There's a little ceremony, and NRC is heavily involved, 15 and it rests on their shoulders because of the role of operators in operating the 16 current fleet.
17 But the licensees now would own that responsibility, and they 18 have to diligently ensure certification requirements are met. And then the NRC 19 inspections must be thorough, and frequent enough to ensure effective operator 20 qualification programs to let the GLRO know look, they're still here, we're still 21 looking, come two years after you got your certification, this kind of doesn't 22 have the same impact.
23 So, let me talk a little bit in closing. Industry has provided 24
23 comments in our meetings about their concerns in Part 53. Some industries 1
support Part 53, some do not. Achieving full consensus may not be possible.
2 In my opinion, there's a lot about balance here. There's a lot of flexibility that's 3
given in framework A for instance, which is really good, but with flexibility comes 4
responsibility.
5 And I think you have to balance that, and that's really what the 6
staff has been trying to do, I think. There are valuable pieces of Part 53 being 7
used by non-LWR applicants today. The reg guides that basically endorse 8
LMP, huge step forward, I think every single advanced reactor applicant that 9
Chair Rempe showed in that slide this morning, we asked them explicitly, they 10 are using LMP.
11 Which in a sense means they're using the heart of framework 12 A. In addition, we think the two new draft reg guides, which I didn't talk about 13 here, the one on how you identify accidents, which is in response to use talking 14 about the need for having some good guidance, and the AERI approach could 15 also be extremely valuable, and to make sure that we don't forget about those 16 reg guides, that's important.
17 Now let me turn to Kairos, and the construction application 18 permit for Hermes. Next slide. Before we get into it, Chair Rempe mentioned it, 19 but this letter, the structure of it reflects our evolving approach for advanced 20 reactor reviews. It builds on NuScale, and SHINE, but it's got a more top down 21 focus. It starts with a little bit of what the reactor is, does, looks like, but then 22 what are the novel features?
23 What are the key safety functions? What are they, how are 24
24 they implemented, how do they work, how do you know they work? What are 1
the principle design criteria, the classification of the components that have to 2
meet those criteria, and how is defense-in-depth implemented in the design?
3 Then into sort of the heart of the safety analysis, the postulated event selection.
4 Safety analysis, and particularly the safety margin, that's 5
something we're looking for, given these new concepts shouldn't be designed 6
right to the edge, there should be some margin. And then are there any issues 7
in the operational reliability realm, worker safety, and at least at a construction 8
permit stage, is there any technology that has to be developed before you get 9
to the operating license?
10 So, that's the way the letter was structured, and that is the 11 way we hope to structure all of our letters. They might not have all of these, but 12 it's kind of a punch list for us how to think about the problem going forward.
13 Next slide is a schematic of the Hermes test reactor. It is a 14 pebble bed reactor using molten salt FLiBe as a coolant. That inner orange-red 15 area is where the pebbles are. They come in through a chute in the top of the 16 reactor, down through the graphite, and enter at the bottom of the core by the 17 fueling chute. There's graphite, there's a reactor vessel. The blue is the decay 18 heat removal system that sits on the outside of the vessel, so in the event of 19 loss of circulation, heat is radially transferred through the pebbles, through the 20 FLiBe, which undergoes natural circulation to the vessel.
21 And then to the system with water is in at sort of an ultimate 22 heat sink. Next slide. So, what are the novel aspects? This is the first reactor 23 application of functional containment. We've seen it in many DOE fuel cycle 24
25 facilities, SHINE actually kind of uses functional containment, but this is the first 1
nuclear reactor application. It's also the first application of what's called Div 5, 2
ASME Section 3 Div 5 developed for high temperature materials.
3 DOE spent a lot of money on getting these materials 4
approved, and in the code, and it's good to see people actually using it. You 5
couldn't design this reactor without it. The pebbles, and the graphite are 6
buoyant in the FLiBe, so they float, and that provides some really interesting 7
design challenges in the design. The pebble here is different.
8 It's not a classic German, and now Chinese high temperature 9
gas reactor pebble. It is small, it's about the size of a marble, and the fuel 10 pump TRISO particles are in an annulus in the middle of the pebble. Because 11 in the German pebble, they're everywhere, except there's an outer line that has 12 no particles, sot here's those differences.
13 There's anti siphon features to limit the loss of coolant 14 inventory in the event of a pipe break. So, basically you can only lose so much 15 FLiBe, and then it just sits in the vessel, so it's always there, if you will. There 16 are what are called fluidic diodes to enable natural circulation when the forced 17 circulation is lost. And then you've got to handle these pebbles.
18 They come out, they get scanned to see if they're fully 19 burned, and if not, they go back in. So, all of that is new, relative to say light 20 water reactors. Okay, next, in terms of our conclusions, and recommendations, 21 we said that the key attributes of the design are the low thermal power, the use 22 of TRISO fuel, and FLiBe coolant as an effective functional containment, and 23 the passive heat removal capability.
24
26 I changed color there, because that means there's another 1
slide coming on that in a little bit more detail. The overall design results, and 2
projected dose consequences with large margins to regulatory citing criteria.
3 And this allows us a unique approach to safety classification components that 4
we'll talk about in a couple slides. Next slide, so what are the safety functions?
5 Limiting release of radionuclides, they use functional 6
containment. Controlling heat removal, as I mentioned earlier, it's transferred 7
by conduction through the fuel pebbles, natural circulation of the FLiBe, and 8
conduction through the vessel. Fluidic diodes to help natural circulation, and 9
the passive heat removal has four independent trains, three of which can 10 remove heat, and testing is planned to verify that it will work as advertised.
11 Controlling reactivity, there are two sets of control elements, 12 four elements in the reflector to control the reactivity, and three shutdown 13 elements that go into the pebble bed to shut down the reactor. Only two of three 14 shutdown elements are needed to accomplish reactor shutdown. Testing is 15 planned to confirm their operation, and behind that is a very strong inherent 16 negative temperature coefficient of the fuel coolant, and moderator.
17 So, some defense-in-depth there. And finally, for any of these 18 safety functions, no AC power, or operator actions are needed to mitigate any 19 design basis event.
20 Let's turn to functional containment. Two inherent robust 21 barriers: TRISO fuel and FLiBe. This unique combination results in very small 22 source terms. Even with Kairos assuming fuel failure 100 times greater than 23 measured in the DOE TRISO fuel program, projected doses are still 100 times 24
27 below the citing criteria. And the doses are not dominated by fission products; 1
they're dominated by tritium generated from the FLiBe and argon-41, which is 2
from activation of the air trapped in the graphite porosity and in the cover gas.
3 Next slide. So, now let me talk a little bit about this functional 4
containment, and what it can get you, and how it helps you with safety 5
classification. So, the reactor vessel is a safety related item, but the piping in 6
the design is not. Historical practice would say, and defense-in-depth would 7
say you should make that piping safety related. Safety analysis takes no credit 8
for the piping.
9 The FLiBe does not chemically react with the air, so the 10 piping doesn't prevent a chemical reaction like in sodium reactors. And then 11 there are these large margins, so which way do you go? Do you go with the 12 historical precedent, or do you do something different? And in this case, we felt 13 the safety margin outweighed the historical practice, but this would be done on 14 a design specific basis.
15 We highlight this here, and put this little box at the bottom of 16 the slide. We think we're going to see other types of departures like this, and 17 the staff SCs sometimes don't really get into some of this rationale, it's just not 18 what they do in the NSCs, but we think it's important for the public to 19 understand that we've gone through, we understand the rationale. Nobody is 20 cutting corners here, and explain that.
21 And this is one of these things with advanced reactors that 22 you're going to see, we're going to see more of in different cases. Next slide.
23 We said because of the first of a kind nature of the FHR technology, there are 24
28 performance uncertainties that can really be best addressed during operation of 1
the reactor itself. The scaled demonstration plant like Hermes will be very 2
valuable to test the technical elements, design features, the safety functions, 3
and the equipment performance of the technology.
4 The key concern that we raised is how is the beryllium, 5
airborne beryllium, and tritium in the facility going to be managed to stay below 6
the relevant regulatory limits, and protect the safety of the workers. This is not 7
an issue at the CP stage, it's more the OL stage, but we felt it had to be in the 8
letter, because it's the key thing in this technology that we have to keep an eye 9
on.
10 So, what are some of the performance uncertainties? To 11 control what's called the chemical potential in the salt, this is to make sure you 12 keep corrosion well under control. In presence of neutrons, and in a 13 temperature gradient where you've got the hot outlet coolant, and the cold inlet 14 coolant, this theoretically looks doable, but has not been demonstrated in a 15 system such as this.
16 FLiBe, if you move off the eutectic composition, the viscosity 17 can change, it can turn from water to molasses, so you've got to control it in a 18 window. Can you control it in an engineering sense? This is something that 19 we'll learn from the operation of Hermes. What are the level of impurities that 20 you're going to see in the salt, and how do they affect fuel performance?
21 TRISO fuel is particularly susceptible to silicon carbide attack 22 by metallic impurities. The chip industry is worried about this, TRISO people 23 are worried about it, and again, you won't know until you actually operate it. In 24
29 addition, one of the issues that we raised was there is uranium that comes in 1
the beryllium fluoride that's part of FLiBe, it comes out of the earth when you 2
mine it.
3 And so, you're going to fission that uranium, and you'll get a 4
mixed waste. And in the old molten salt reactor experiment, disposition of that 5
salt was extremely difficult, but it had a lot more uranium. And so, we asked the 6
question, well, have you looked at this? And they assured us that they had, 7
and that they have disposition path, which was good, because that would be 8
really important for the technology.
9 Next slide. As noted in the staff SC, there is confidence that 10 this facility can be constructed in accordance with the relevant regulations, and 11 the design basis that's outlined in the SAR. There are still detailed design 12 analysis, and technology qualifications that will need to be completed prior to 13 the operating license review, and we'll have a list of those in the next slide.
14 One thing that was not talked about by the staff was 15 combustible gas generation associated with graphite oxidation. This is not 16 hydrogen, this is carbon monoxide, and so we felt that should be included in 17 evaluations going forward. And that we felt that the construction permit should 18 be approved. In terms of what's the punch list of things left to confirm the 19 adequacy of the design of these SSCs.
20 Fuel pebble behavior, the experiment's planned on the wear 21 of the pebble, graphite dust. FLiBe infiltration into the porosity, of that happens, 22 that could be a bad day. There's a number of tests relative to the high 23 temperature materials, and the graphite qualification surveillance that they plan, 24
30 oxidation of graphite. We know a lot about oxidation of different grades, this 1
specific grade hasn't been studied as much.
2 Validating the computer codes, developing this fluidic diode to 3
make sure that it'll work. Justifying the thermodynamic, and vapor pressure 4
correlations that are used to calculate the source terms, and developing the 5
sensor technology for the chemistry is also very challenging here. Something 6
that will work for as long as the reactor plans to operate.
7 Kairos is committed to finishing these before completion of 8
construction, and the staff has noted these items in their review. They have 9
something called Appendix A of the SC, it's kind of like their punch list. So, 10 everybody is sort of aligned, and it's good to see that we've got that list. And 11 with that, I will turn it back over to Chair Rempe.
12 DR. REMPE: Thank you, Dave. This completes our prepared 13 remarks, and we'd now like to welcome questions from the Commission.
14 CHAIR HANSON: Thank you, Chair Rempe. We're going to 15 begin this morning with Commissioner Crowell.
16 COMMISSIONER CROWELL: Thank you, Mr. Chair, thank 17 you Dr. Rempe, thank you to all the ACRS members who are presenting today, 18 and are here as well. In my short time at the Commission I've enjoyed our 19 interactions, and getting to know all of you, and the important role that ACRS 20 plays. Actually going forward would like to see you guys more regularly at 21 some more routine meetings we do, rather than just once a year, so maybe we 22 can work on that.
23 A lot of questions, I'm going to try to pepper all of you with 24
31 some of them with my time I have here. But Dr. Rempe, I wanted to start with 1
you, and just I see the ACRS mission, and the value they play is critically 2
important for the NRC, and commercial nuclear as a whole, because it's the 3
belt, and suspenders approach that the NRC, and ACRS play is part of the 4
heart of maintaining, and building public trust.
5 So, we've just got to make sure we're doing our jobs well, and 6
we're doing them fully coordinated, but independent as well, and efficiently. So, 7
could you talk a little bit more about the process improvements that you guys 8
have self-identified at ACRS that you're hoping to implement going forward, and 9
particularly if there's any of those that maybe apply to NRC staff, that they could 10 adopt as well?
11 DR. REMPE: Thank you for your comments about ACRS, 12 and your question. I tried to highlight some of the process improvements in my 13 presentation today. The fact that we are working with this new evolving 14 approach, and conducting these design centered reviews, so that we have 15 reduced the number of meetings, and presentations by the staff, and the 16 applicant.
17 It does require that members are very proactive, and working 18 together with -- again, we have our ACRS staff member with us to preserve the 19 independence, but as well as the NRR staff. And I think it's working well.
20 Today I think I mentioned, I hope I did, that we did complete the Kairos review 21 four months ahead of the agreed upon schedule, and that takes close 22 coordination, as Member Ballinger indicated in the SHINE review, as well as 23 Dave indicated in the Kairos review.
24
32 We are trying to look for other process improvements such as 1
the way we conduct the SLR reviews, and then I think this guidance that we've 2
been working on is actually very beneficial, and I think as we move forward, that 3
that's where we're going to get the most bang from our bucks for trying to 4
improve things. Because if you look at the workload coming down the pipe, 5
there's a lot of these design centered applications coming through.
6 And the more that we can do to agree on the process for what 7
should be done, and get agreement from NRR staff with our, again, ACRS staff 8
present on how we'll conduct this, I think it'll be a more process oriented 9
approach where we hit, as Dave mentioned, the key points of what we expect, 10 and what we're going to be looking for, and everyone understands the ground 11 rules.
12 And I had mentioned that our guidance development effort 13 includes a Committee engagement plan, and we actually had a meeting with 14 NRR staff present, and discussed where we believe the status is, and the four, 15 or five projects that were discussed during that meeting this week, I think there 16 was agreement on -- we didn't hear any disagreement from NRR staff.
17 Maybe we'll hear something later, but yeah, this is where we 18 think things are coming in, and what we would expect for the upcoming review.
19 So, I think that's where we should focus in the near term to get the most 20 process improvements. Does that answer your question?
21 COMMISSIONER CROWELL: It does, and I appreciate that. I 22 will add, if you don't mind, on your behalf, that you're also looking to round out 23 the membership of ACRS, and with the goal of specific expertise so you can 24
33 handle an increased work load, and it's something that the NRC needs to be 1
focused on as well, the increasing work load, and having the right matching 2
expertise, so thank you for all of that that you do.
3 Dr. Kirchner, I think I want to talk about EPZs for a little bit.
4 When you are going to move to review of the NuScale combined operating 5
license, I believe you said that you're going to review that, are you going to 6
consider in the applicant both an ingestion pathway, and a plume exposure 7
pathway?
8 DR. KIRCHNER: The answer is yes. The focus of the 9
methodology of course was on plume exposure pathway, and that was what we 10 reviewed, and I presented today, but yes, that comes back with the actual COL 11 application, and of course the ingestion pathway is a much more site specific 12 set of considerations depending on obvious things, location, location, location, 13 and such.
14 But that same -- the existing rules that are in place, I think will 15 cover the proper review of the ingestion pathway considerations.
16 COMMISSIONER CROWELL: I know in your presentation 17 you mentioned the focus on seismic is a key safety parameter, something we 18 need to account for. Is that based on the technology's susceptibility to seismic 19 activity, or based on the presumed site selection?
20 DR. KIRCHNER: Well, it will be both. I think the technology 21 is pretty robust at this point, and also with this evolutionary LWR design, I think 22 what we're seeing is that the frequency of events is much lower compared to 23 the existing fleet when you start going through potential event sequences. The 24
34 dose, the source term is lower because the units are smaller, and that's almost 1
the linear kind of reduction, and the potential source term.
2 And the design characteristics, for example, the NuScale 3
design are such that the time to release also is a much slower process, so there 4
are a lot of things that are lining up in favor of doing that kind of analysis, and 5
allowing one to, with conservative assumptions, to pull back that EPZ boundary 6
definition.
7 COMMISSIONER CROWELL: Thank you, appreciate it. Dr.
8 Petti, talk about Part 53 for a quick second, I appreciated both of your 9
presentations, but I wanted to focus on Part 53. I appreciate the point ACRS 10 made last year about the balance of rule versus guidance, or formal regulation 11 versus guidance in the new Part 53 rule. I mean, I think you guys flagged that 12 in your early letter last year.
13 And since the Commission's had a chance to receive Part 53, 14 and have a meeting on it, I think all of us are now thinking about what is that 15 right balance between rulemaking, regulation, and associated guidance. ACRS 16 says that it probably should be done for a variety of reasons, including just for 17 general optics, and stakeholder support.
18 But is there a way ACRS could provide more insight on what 19 areas may be ripe for guidance, or work with staff on that as appropriate?
20 Because I think it'd be helpful if we're going to move in that direction, to have an 21 informed, and substantiated reason for why we're putting some things in 22 guidance, and others not putting them in guidance.
23 DR. PETTI: Sure, I think there's a way that we could do that.
24
35 We have seen an initial list of all the regulatory guides, and they're quite 1
extensive. What we haven't done is gone through them with the staff, and from 2
a risk perspective, say these look important, these don't. That's something that 3
we could definitely think about going forward.
4 COMMISSIONER CROWELL: I think it'd have a lot of 5
validation, particularly for the public, and stakeholders that we're thoughtfully 6
thinking about what should be in guidance, versus what maybe is not 7
appropriate. And not streamlining the rule for the sake of streamlining, but 8
doing it in an informed way.
9 DR. PETTI: To me the issue that I struggle with is sure, it's 10 easy to say put it in guidance. But if it's in Part 50 and 52, in the rule, you've 11 created now a difference, and that's a boundary condition, the staff said no, we 12 can't do that. So, many of the issues I think fall in that sort of category, where 13 changing it would open up that difference, and that has all sorts of ramifications, 14 I think.
15 COMMISSIONER CROWELL: It does, and I'll return my 30 16 seconds, and let that just hang out there for a while.
17 CHAIR HANSON: Do we need to take a moment of pause, of 18 reflection on that? I don't know. Thank you, Commissioner Crowell.
19 Member Ballinger, I wanted to start with you this morning.
20 Both SHINE and Kairos applications rely on NUREG-1537, which is the 21 guidelines for preparing, and reviewing applications for the licensing of non-22 power reactors, right? Which uses deterministic approaches, such as single 23 failure criterion and maximum hypothetical accident, I think, which you've noted 24
36 in your slides, to evaluate SSCs and components. And NUREG-1537 doesn't 1
require use of risk assessments like PRA.
2 But do you see, potentially, I guess, a potential for broader 3
application of 1537 being applicable to power reactors that employ simpler 4
designs and passive inherent safety features?
5 DR. BALLINGER: Wow, that's a good question for which I 6
don't have -- I'd have to think about the answer to that. With respect to the 7
SHINE application kind of fell into the sort of grey area between risk-informed, 8
completely PRA-related, and deterministic. But the SHINE -- gosh, I hate to say 9
I'd get back to you on that, but I won't.
10 CHAIR HANSON: I thank you for your candor.
11 DR. BALLINGER: I think, yes, in some respects. I think so, 12 especially with the newer advanced reactors, where there's a clear, as Member 13 Petti has outlined, huge margins. I think that's my story, and I'm sticking to it.
14 DR. REMPE: If I could supplement?
15 CHAIR HANSON: Yeah, anyone.
16 DR. REMPE: One of the things that I think members were 17 very pleased with with the SHINE application is they did a qualitative risk 18 assessment, and they had a risk matrix. And when I hear some of the 19 discussion about you don't want to do a PRA, I think people too often focus on 20 a full scale PRA, and this simpler risk matrix is -- again, I can remember 21 Member Bley when he was still on the Committee, people need to think about a 22 simpler design could have a simpler PRA.
23 And this risk matrix was a great thing to see in the SHINE 24
37 application, and I personally was very pleased with it. And I think Member Petti 1
would like to jump in.
2 DR. PETTI: To me, the big difference in 1537 is the lack of a 3
requirement in the risk area. But I think you could do something, this risk matrix 4
comes from DOE, because they deal with so many different oddball facilities, 5
they've had to do a lot of thinking here that I think you could think about doing 6
that here. I also agree, I even think full PRAs on advanced reactors will be 7
much simpler than on the existing fleet.
8 This idea that it's a burden, we specifically asked the lead 9
person who developed the non-PRA standard that question to confirm what my 10 gut said. He said absolutely, there's fewer systems, there's fewer interactions 11 between systems. Water reactors are fairly complicated, water, water 12 everywhere sort of thing. Go ahead.
13 DR. BALLINGER: Recall, remember that in the rest of the 14 world, they use, they call it failure modes and effect analysis. To this 15 metallurgist, that sounds a lot like the initial part of a PRA, which is what they 16 did.
17 CHAIR HANSON: We have this concept of incorporating risk 18 insights, which is PRA, certainly related, but isn't necessarily the full-blown 19 thing, but is important for reviews. So, thank you, I appreciate that discussion.
20 DR. PETTI: I sometimes think the risk insights are the most 21 important. Calculating the number is not as important as getting those insights, 22 because they influence design, they influence how the regulator thinks about 23 things, those insights are really important.
24
38 DR. BALLINGER: Remember, 1537 was actually, there was 1
a modification to it for this application.
2 CHAIR HANSON: Okay, yeah, thank you. I had forgotten 3
that, appreciate that, thank you.
4 Member Kirchner, I wanted to touch on this EPZ, and you 5
said something that really caught my attention. I think it was there are a lot of 6
factors that go into the EPZ sizing, you don't just push a button and the number 7
pops out. And that's really, in my book, kind of the difference between being 8
kind of risk informed, and risk based.
9 And I wondered if you could just kind of say a little bit more 10 about not solely relying on quantitative results from some kind of PRA, or risk 11 based approach.
12 DR. KIRCHNER: Well, the advantage that, for example, 13 NuScale has, or any evolutionary LWR would have, would be to draw on the 14 huge operating experience that's out there with the fleet, with the equipment, 15 the components. We talked about failure modes and effect analysis. So, 16 you've got a much stronger base to deal with. But more to your question, as we 17 expect the advance reactors in general consistent with your policy, to -- Dave 18 mentioned this, be more reliant on inherent passive safety features.
19 So, we expect more margin, we expect that they'll be more -- I 20 used the word for NuScale, robust in terms of their design. I think the challenge 21 comes in in areas like for NuScale, if the seismic initiator is dominating their risk 22 profile, and now we're getting into a space that becomes -- has a lot more 23 uncertainty. The debate between the staff, and the applicant was pretty much 24
39 about how do you define the edge.
1 Where do you define the cut off, and in the end it's really 2
qualified engineering judgment that applies. So, that's an example where you 3
have numbers, and you basically have a fairly high level of confidence that this 4
is conservative, the result. But it takes that added engineering judgement, and 5
that's what I was trying to allude to when I said it will be on a case by case 6
basis. And then the other thing that we have to look at is are there additional 7
hazards.
8 And the proposed rule also requires you, and I didn't talk 9
about that at all today, but the proposed rule requires you to look at other 10 hazards off site that might impact the execution of your own emergency plan.
11 So, that's an example of additional consideration. So, it's just not enough to 12 turn the numbers, and come up with the -- the other challenge that I didn't 13 mention is that what we're likely to see, and we'll probably see this with 14 NuScale.
15 Is that the calculated result will be within the exclusionary 16 boundary of the plant. Now, when you come in close, now I'll get a little 17 technical, wake effects, and things like that become important in how you do 18 the dose analysis. So, 0396 was based on classic dispersion, weather 19 patterns, and so on. That works very well when you're looking at ten miles, and 20 you have all the history of the site, and you can factor that in.
21 Now when you're very close in, you have to look harder at 22 other things. For example, there are advanced methods for looking at close in 23 dispersal, and dose effects that are used to currently analyze the control room 24
40 dose. There's a code called ARCON that is often used for this purpose. So, 1
that doesn't directly answer your question, but there are a lot of factors that will 2
go in that go beyond just that calculation of the EPZ radius.
3 CHAIR HANSON: Thank you, I appreciate that. One last 4
question from me. Member Petti, I wanted to ask, the construction permit 5
application for Kairos doesn't include a request for authorization to possess 6
special nuclear material, and that's going to get addressed in the operating 7
license, obviously. But based on your review of Hermes so far, can you offer 8
any perspectives on the design from a material control, and accountability 9
standpoint?
10 DR. PETTI: The biggest issue is the storage of the pebbles, I 11 think. But if they're fully burned, they're not going to produce much of a risk 12 from proliferation. There have been many studies looking at TRISO particles.
13 When you go to these high burn ups, they're really not very attractive compared 14 to others. There's an argument over whether they're more proliferant because 15 it's a different fuel form.
16 I describe it as different compared to a fuel rod. I think if they 17 had anybody that could read things in the literature, if you really want to do it, 18 you could do it, I mean it's not that difficult.
19 CHAIR HANSON: Thank you very much. Commissioner 20 Baran.
21 COMMISSIONER BARAN: Thanks. ACRS plays an 22 incredibly important role in our licensing reviews, so thank you for your hard 23 work, and your valuable insights, I appreciate it. With an increasing number of 24
41 new reactor applications anticipated in the near term, there's understandably, a 1
lot of stakeholder focus on NRC's ability to review all the applications that come 2
our way, and to do so with efficient, effective, and timely process.
3 The agency has received a good number of suggestions for 4
how we can improve our processes, and some of those relate to ACRS. For 5
example, the Nuclear Innovation Alliance recently issued a report on ACRS with 6
some recommendations. Joy, I'd be interested in hearing your thoughts on the 7
recommendations.
8 DR. REMPE: Thank you, Commissioner Baran, for that 9
question. I am aware of the recommendations in that report, as well as several 10 other reports, or letters that have been provided by stakeholders recently that 11 do mention ACRS, and I do appreciate the opportunity to comment on them 12 today. I first want to say that I think I speak for all of the members in saying that 13 we are very receptive to suggestions for improving our processes.
14 All of us want to be as effective, and efficient as possible. In 15 the case of the NIA, the report that was solely on ACRS, I think that members 16 would agree generally with many of the suggestions, and recommendations in 17 that report. But I'd also note that we have identified many of those 18 recommendations, as well as received input from NRR staff, from applicants, 19 the Commission actually in the last several years.
20 And we, as I hope I communicated during my presentation 21 today, have taken actions, and made significant progress in reducing the 22 number of duplicative meetings, streamlining our review process, reducing the 23 number of reports, so that we can focus on risk important topics that we provide 24
42 the Commission. And again, we are continuing to try, and improve these 1
processes.
2 I'd briefly like to note that there's some misconceptions in that 3
report, perhaps due to a lack of understanding of our processes, our impact on 4
schedule, and our costs. So, I'd like to put a flag out there to say wait, don't 5
believe everything, because maybe there's some miscommunication there, or 6
some omissions there on the full aspects of what we've done.
7 And then finally I'd note that I personally have some concerns 8
about three of the recommendations in that report, because I believe that they 9
would adversely affect the schedule for the Commission to complete their 10 milestones, they might not be a wise use of agency resources, and then I have 11 a lot of questions about one recommendation that I believe might adversely 12 affect our ability to support the agency's safety mission.
13 I'm talking about recommendations to narrow the scope of the 14 ACRS review to novel aspects of applications that affect safety significance.
15 Today I think you've heard several examples where ACRS identified items that 16 were not in the initial application, or the staff SC affecting boron dilution, or 17 combustible gas generation for example. I'd note that these are not novel 18 issues, or new phenomena.
19 And I would question how, if that scope is narrowed, if we 20 would still be able to identify such issues. But again, I want to emphasize that 21 we do appreciate comments, and suggestions, and we are trying to improve our 22 processes. Does that answer the question sufficiently?
23 COMMISSIONER BARAN: Yeah, very much so, thank you.
24
43 DR. REMPE: Maybe more than you wanted to hear.
1 COMMISSIONER BARAN: No, that's great, I wanted to get 2
your sense of it. The Part 53 new reactor regulatory framework is obviously a 3
major focus for the Commission right now. We had a great discussion with the 4
NRC staff, and a panel of external stakeholders a few weeks ago. We've also 5
received five letters from the Committee, which I found very helpful.
6 I'd like to get your perspectives, either as a committee, or as 7
individual experts on some of the tough issues we're all grappling with. There's 8
been quite a bit of discussion about whether QHOs should be a cumulative risk 9
performance standard in the rule. The safety goal policy statement includes 10 qualitative health objectives, and quantitative health objectives.
11 What do you think about including the qualitative health 12 objectives in the rule, and the quantitative health objectives in guidance, or are 13 there other approaches we should be thinking about in this area?
14 DR. PETTI: The concern that I have is, I mean quantitative 15 QHOs have been around for a while, I could cite industry documents, the non-16 PRA standard, I could cite Commission policy statements, other internal 17 documents. You need a cumulative risk metric as a requirement to close the 18 loop to say do you have the same level of safety as Part 50 and 52. Without 19 that, the staff may be required to have to implement some new requirements to 20 assure themselves that they have the same level of safety.
21 That said, I think there are many risk surrogates that could be 22 developed, because we outline one of ours, that we're concerned that the LWR 23 risk surrogates may not work for some of the advanced technologies. For 24
44 instance, the protective action guidelines. If you can meet the protective action 1
guidelines, you should implicitly have met the safety goals.
2 And the staff, I'm sure, could do the math, and prove that in a 3
way. So, I think there's some ways to prove it numerically. But without it in the 4
rule, and in a quantitative way, I think it is a hole.
5 COMMISSIONER BARAN: Okay. Any other thoughts on 6
that?
7 DR. REMPE: I just would note, that we have one member, 8
Member Bier, who has a passion about the safety goals, and again, it's not -- I 9
know the agency spent a lot of resources to come up with the safety goals. But 10 she's convinced the membership that it's worth us having some exploratory 11 activities where we periodically hear from outside experts about the history of 12 the safety goals.
13 And I believe that her underlying objective to see if there's 14 some insights that we might be able to gain. And I guess if it's acceptable to 15 you, I'd offer her the opportunity if she'd like to add any thoughts on that.
16 COMMISSIONER BARAN: Please, yeah.
17 DR. BIER: Yeah, I do think it's worth, as Joy said, relooking 18 at the safety goals now in light of new reactor designs, so we do have a small, 19 kind of informal working group going forward. Former Commissioner 20 Apostolakis is going to speak to us about this in August, August 24th, I believe.
21 And I think it's too soon to say whether we are going to have any concrete 22 recommendations out of that process.
23 But I think when you look at both smaller reactor sizes, 24
45 inherently safe designs, and the fact that the rest of the world has gotten safer 1
also, we're not necessarily competing against coal plants anymore as the 2
alternative energy source. I do think it's worth just taking another look at it, and 3
maybe a year, or two from now I'll have more to say about that concretely.
4 Thank you.
5 DR. REMPE: And just for clarity I note that the briefing 6
interaction with Former Commissioner Apostolakis will be held as an open 7
subcommittee meeting under the Policy and Procedures Subcommittee. So, the 8
working group discusses it, but we have these presentations, they are posted, 9
and meet all the FACA guidelines.
10 DR. BIER: Yes, thank you.
11 COMMISSIONER BARAN: Thanks, very interesting. Let me 12
-- there are so many different questions I could ask, so many different topics to 13 cover. Maybe I'll ask one of the big questions is this idea whether we need two 14 frameworks in the rule, or could have just one that would cover everything.
15 Dave, I got the sense from you, you were pretty skeptical given the 16 philosophical differences between the two frameworks, that it was practical 17 really to pull them together.
18 I'm interested in any thoughts you, or others have about, I 19 guess both the desirability of having one framework, rather than two, and then 20 the practicality of combining them, or I guess desirability, or practicality of a 21 more guidance approach, someone suggested that, don't try to combine them, 22 put those two frameworks in guidance, and have just higher level performance 23 criteria in the rule. Any thoughts about that?
24
46 DR. PETTI: In terms of one, or two, I think of it as you come 1
to the fork in the road, and you have to decide to go left, or right. They both get 2
you to the destination, but they're two separate highways. So, practically I don't 3
know there's a big difference. If you combine them, it's like being on a road, 4
and you've got to get off of this -- if you want to do more risk based, you've got 5
to get off at this exit.
6 But you stay on, and you get off, and there's like 15 different 7
exits that you're going to have to get on, and off of. So, it's difficult. I think 8
there's a greater chance to mess up, because you'll have to say well, if you're 9
going to do this, if it's this approach, this is what you're doing, if it's not, then it's 10 that approach, so I think practically it's a concern.
11 This idea of moving the framework stuff into guidance, my 12 view is it's kind of like what the Brits do, because the Brits have a very high 13 level sort of thing. They have a handful of reactors. Our existing regulatory 14 fabric, to put framework A, and B, what are the safety functions, what are the 15 design criteria down in guidance, you've created a huge difference from 50 and 16 52 in my opinion.
17 Never mind just the enforceability, it's a different level of 18 safety, because then they can say no, we don't want to do that, we're going to 19 do this. And that will just extend, because that will just open up questions in my 20 mind. I'm not as worried about the two separate rules. Initially, we had many 21 discussions in the Committee about, why don't you combine them?
22 But if you go back and read the preamble, and understand the 23 foundations beneath it, you really see that they're really different. And although 24
47 at first brush they look similar, the rationale for them is different enough that 1
combining them is, as I said, it's like oil, and water. In a sense, it's just you 2
decide which highway you're on to get to the answer.
3 COMMISSIONER BARAN: Thanks, very helpful.
4 CHAIR HANSON: Thank you, Commissioner Baran.
5 Commissioner Wright.
6 COMMISSIONER WRIGHT: Thank you, Chair. And thank 7
you very much for your presentations, there's a lot that's floating around out 8
here, and I don't know that we can assuredly cover it in the two hours that we 9
have, but I want to appreciate what you do, your willingness to serve, and to do 10 this. It's a very difficult job at times, and I thank you for what you do.
11 Joy, I'm going to start with you, you're the leader, so we're 12 coming to you. You spoke a little bit about the NIA report a second ago, we 13 also had the INL report that was out there too, that was one of the ones you 14 kind of referenced without naming it. And I heard your comments when 15 Commissioner Baran was talking to you.
16 Can you give me your thoughts, and I understand your 17 position where you're coming from, but if we understand what the industry is 18 saying, and what these trade groups are saying as well, these NGOs, the first 19 of a kinds are coming, right? And the intent is for them to be standardized, the 20 intent, because they're trying to meet national security goals, global security 21 goals, carbon goals, you pick one.
22 But when you get down to it, they're looking at potentially 23 streamlining this, okay? So it's your first of a kind, maybe up to two, or three, or 24
48 four before you get to your Nth of a kind cost, and stuff like that, and if they are 1
truly cookie cutter designs, to simplify it. What are your thoughts on the 2
benefits of reviewing every application in that case, if we're on an Nth of a kind 3
review? Which is I think that's what the intent of what the comments are.
4 DR. REMPE: Again, I think ACRS doesn't want to waste time 5
on looking at issues we've already looked at. But on the other hand, if it's put 6
in, for example, if the Atomic Energy Act were to change, one might say well, do 7
we really need to do a standard design approval if you've already done a 8
reactor, or you've got a certified design? Well, is it really the same, or did you --
9 we've had changes where they're significant power upgrades.
10 Is that really the same? So, I guess that was one thing, you 11 need to be careful how that language is changed.
12 COMMISSIONER WRIGHT: So, I understand, because we're 13 all stuck, the agency is still stuck in that one off big plant design, they're all 14 different, and I understand that. But in this situation, what we're hearing, and I 15 have no reason to dispute it, because you keep hearing every CEO, every 16 CNO, every designer talking about it, that this is going to be our design.
17 If you want to do something different, we're not selling it to 18 you. This is how it's going to be. Once we get a design certified by the NRC, 19 that's what we're going to sell, that's what we're going to go to market with.
20 Now, maybe down the road they may change it, and again, I'm all for it, but if 21 we're really talking that way --
22 DR. REMPE: If we're really talking that way, then you start 23 looking at site hazards, and co-located hazards, and things like that. But I think 24
49 that ACRS --
1 COMMISSIONER WRIGHT: Exactly, which is not really 2
novel, right?
3 DR. REMPE: The staff would be able to deal with it. But 4
again, I'm thinking of what's coming down, and if changes were made, what if 5
you have a certified design, but you say I haven't built it yet, and I'd like to 6
tweak it, well how big is that tweak?
7 COMMISSIONER WRIGHT: Well, that's a change --
8 DR. REMPE: Yeah, again, that's how you change it.
9 COMMISSIONER WRIGHT: But that's not what we're 10 hearing, okay? And that's what we have to pay attention to, I understand that, 11 right?
12 DR. REMPE: Yeah, but then again, I'm from Missouri, and I 13 guess I look at what I see written down in front of me in the near term, and so I 14 would be careful, and make sure that the -- how one focuses that scope is done 15 very carefully so that one doesn't miss some things.
16 COMMISSIONER WRIGHT: I mean I understand, we've 17 heard -- not to pick on him at all, but we've heard Jeff Lash over at TVA talking 18 about hey, I'm coming not with one, but my intent is to come with 12, or 20, and 19 we're going to do them all the same to start with, and once we get some of it 20 done, the fast followers are coming, right? And they're going to be the same 21 way.
22 So, I understand, so I think we as an agency have to be open 23 to get into more of a production kind of mind set, rather than a one off review on 24
50 everything.
1 DR. KIRCHNER: I think, Commissioner Wright, I think it 2
would be a very expedited review. If indeed they achieve the Nth of a kind, and 3
there weren't substantial, or significant changes in the design, such as a major 4
power upgrade, or something. We are seeing that, I think we mentioned in your 5
presentation, we touched on SLA, subsequent license renewal applications.
6 The first two, or three that we looked at, we took a lot more 7
time, but our colleague Matt Sunseri, who was former chair, took a much more 8
expeditious, or expedited approach to how we would do those reviews. So, we 9
learn from the application of the GALL reports for SLR, and we know what to 10 look for on the subsequent applications. Because it's not a one to one match 11 for your example.
12 But it's an example of how I think both the agency has 13 expedited their reviews, and focused on the key aging issues, and we've done 14 the same. So that typically it's one meeting for that particular review.
15 Theoretically, if we get to the Nth of a kind, that would be great for the industry, 16 and for the agency. I think our review would be just perfunctory almost.
17 COMMISSIONER WRIGHT: Well, quite honestly for the 18 world.
19 DR. KIRCHNER: But as Joy pointed out, the other big issue 20 would be the siting.
21 COMMISSIONER WRIGHT: Right, and I understand that.
22 DR. PETTI: I mean we touched on it earlier, if the engineers 23 are doing their job right, they're engineering out all the internal initiator risk, and 24
51 your risk sits with the external, and that's kind of a different setup, right? So, 1
when you go to site selection, that's why the seismic stuff is so important. If you 2
can get a seismic isolator, then you decouple yourself from the site a little bit.
3 Then you don't have significant site adaptations, and things like that.
4 That's where the answer is going to be, and I don't think we've 5
ever kind of been in that situation, where we've got to worry about -- the 6
external stuff is what's really important. But I agree with Walt, if it's truly Nth of 7
a kind, yeah.
8 DR. REMPE: I'd also note that when we had this international 9
exchange, we have seen other examples, in France for example, where that 10 type of situation, and there's a class. So, there's international experience for 11 this too.
12 COMMISSIONER WRIGHT: Yeah, but I do think that the way 13 things are being presented today, it is a paradigm shift because of the global 14 security nature of this. And if we don't get it right here in the U.S., they're not 15 going to be able to sell anything across the pond, because it takes that here.
16 I've heard that more, and more recently, and I believe it's true. So, I'm going to 17 go a little bit further with you in the couple minutes I got.
18 So, you mentioned earlier that you're continuing to streamline 19 your reviews, right? And I like that, I think it's awesome. Okay. Anything we 20 can do to make things more efficient, I'm all for it, as long as we're hitting that 21 safety strike zone. So, let's talk a little bit about the meetings too. So, I mean 22 you can speak, and I appreciate you speaking on how you're really looking at 23 streamlining your processes.
24
52 But how are you addressing outside concerns as well, that 1
technical questions during the meetings can veer past the point of addressing 2
safety significance, and more into the area of technical curiosity. Can you? Are 3
y'all getting a handle on that too?
4 DR. REMPE: I believe in recent years you'll see that 5
sometimes other members will tell a member hey, we already discussed that.
6 So, we are cognizant of that. I would also though, in fairness to those kind of 7
comments, would note that our process sometimes is a probe to understand if 8
something has been addressed. I think the issue about the combustible gas 9
generation might have surprised some of the applicants when we first brought it 10 up a bit.
11 And although they said they were starting to develop models 12 for it, there was no indicator that that had been considered in the application.
13 And so, again, it may come as a bit of a surprise, and sometimes we bring it 14 back, and explain why we're interested in that issue, but I think sometimes our 15 questions may be perceived as off target. And if the member can't justify it, 16 then we will move on, and it's not just intellectual curiosity we hope.
17 COMMISSIONER WRIGHT: Okay, thank you. And I'm going 18 to come back to you real quick with the 30 seconds I've got. So, you mentioned 19 your visit to SHINE last year, and I recognize the value of seeing the facility in 20 person, it always makes an impression, it helps, right? But I'm really interested 21 in hearing a little bit more about how those interactions at the site helped you 22 better inform your decisions, and gave you better insights, can you get a little bit 23 more specific about what you --
24
53 DR. BALLINGER: Yeah, that's a very simple answer, yes.
1 COMMISSIONER WRIGHT: How, in what way?
2 DR. BALLINGER: When you talk to the people at the site, 3
you get -- you're standing around, and you're getting to ask questions which you 4
would not see, you wouldn't even think of if you're reading a chapter.
5 COMMISSIONER WRIGHT: Like what? Give me an 6
example.
7 DR. BALLINGER: Like characteristics of the site, shielding, 8
interaction with the public, the airport that's within walking distance of the thing.
9 And also the design itself, and the safety issues related to design, the hot cell 10 setup, all this kind of stuff. And you get to ask questions, especially they 11 provided what I would call the overall construction manager, as well as the 12 technical person.
13 And those folks answered every question that you could ask.
14 And so, as a result of that, when it came back to assembling the chapter letters, 15 and putting the overall letter together, that had a big effect on how we 16 constructed the letter. We may say well, going in we should discuss this. We 17 went out there, and we talked to them about this topic, and we now understand 18 it a lot better, and we don't need to put that in the letter. So, I can't emphasize 19 that more.
20 COMMISSIONER WRIGHT: That's what I was trying to drill 21 down to to get some specifics, so thank you for that, I appreciate it. Thank you, 22 Chair.
23 CHAIR HANSON: Thank you, Commissioner Wright. And 24
54 we'll finish up here today with Commissioner Caputo.
1 COMMISSIONER CAPUTO: Good morning. I'm glad to be 2
part of this meeting today, but I'd like to start by welcoming Dr. Vicki Bier. Dr.
3 Bier, I'm sorry I'm not there to say hello to you in person, go Badgers. I didn't 4
actually have a class from Dr. Bier, but I remember her well from my time at 5
UW, and I'm thrilled to see you participating on the ACRS. Dr. Petti, thank you 6
for briefing us on the Kairos Hermes test reactor review, and how it built on the 7
lessons from NuScale, and SHINE reviews.
8 I understand that the committee held ten meetings over the 9
course of three years for a review of seven topical reports for both the non-10 power, and power reactor applications of Kairos' technology. For the non-11 power test reactor construction permit, the Committee held four multiple day 12 meetings at the subcommittee level, and one meeting at the full Committee over 13 this three year time span.
14 Was the Committee able to gain any efficiencies from the 15 extensive pre-application interactions on the topical reports?
16 DR. PETTI: Yes, thank you, very good question. Absolutely.
17 When everything came together for the full Committee, we had the answers 18 already from the topical report. So, we really like the pre-engagement, and the 19 early topicals. It kind of just aligns everything in your mind, so that when you 20 see the application, you understand yeah, okay, now I remember that there.
21 So, it's the same thing as the chapters, you can't just review 22 one chapter in absentia of another chapter, they're so interactive. So, that's this 23 whole sequencing thing that really has a lot of efficiency gains, but you've got to 24
55 think it all through, and that's a huge lesson learned, and we're going to use it 1
going forward.
2 COMMISSIONER CAPUTO: Okay. In the future, when the 3
Committee is reviewing a Kairos power reactor application, do you expect the 4
Committee's level of effort to increase, and include additional meetings?
5 DR. PETTI: Hard to say at this point. Certainly the 6
documentation itself will be larger in volume, and there will be more detail. If it's 7
only at the CP stage, maybe not. That may be more sort of an OL question, 8
because at the CP, you've got a lot more flexibility. So, at the power reactor 9
stage, it may be, particularly if they take all the lessons they learned from 10 Hermes, and apply it, I think the CP could be faster, assuming they're going to 11 go Part 50.
12 COMMISSIONER CAPUTO: All right, and going forward, do 13 you anticipate the Committee's level of effort to be similar for other advanced 14 reactor technologies we varying degrees of pre-application engagement?
15 DR. PETTI: Yes, but again, depending on the technology, 16 and what they bring, and the level of detail that they bring. Almost all of them 17 that we've talked to are doing a Part 50 two step. A lot of them are well along 18 on their technology development. From what we can tell, we know what the key 19 topical reports are that are in the system, Joy talked about, that we reviewed 20 with NRR staff.
21 Looks like the top five that she had on her slide, they have the 22 right topical reports, everyone is kind of following everybody else, and that's 23 good, I think that's going to help streamline things. And I honestly think the way 24
56 we think about the letter, and how we probe, and think about it is also going to 1
help that.
2 COMMISSIONER CAPUTO: So, given the level of effort that 3
you've had on Kairos, and anticipate going on the future, and I understand what 4
Chairman Rempe discussed in terms of cautioning against new, and novel 5
reviews, but isn't it going to be awfully difficult for the ACRS to not only review 6
initial designs, or initial licensing on these technologies, but also to review a 7
consistent work load, hopefully, of these designs going forward?
8 Which gets back to Commissioner Wright's discussion about 9
shouldn't get this to be fairly routine, and wouldn't it be the wisest use of the 10 Committee's time to be doing new, and novel, or initial reviews of technologies, 11 rather than each, and every subsequent license?
12 DR. PETTI: Again, depending on if they're truly talking about 13 a standardized design, and they have an SDA, and nothing has varied, then 14 you're left with just evaluating the site differences. That should be possible at 15 Nth of a kind.
16 COMMISSIONER CAPUTO: Okay. I appreciated the 17 discussion so far on the Part 53 review, and Commissioner Baran's question on 18 quantitative health objectives. I'd also like to make a few observations on it, 19 since the proposed rule is certainly at the forefront of the Commission's focus 20 right now. As Dr. Petti pointed out, the staff's proposed framework A builds on 21 the licensing modernization project that the Commission approved for use as 22 guidance in 2020.
23 And that guidance, Reg Guide 1.232, is one of the valuable 24
57 pieces of Part 53 that's currently being used by applicants under the present 1
Part 50 and 52. There's a lot to like in Part 53 with regard to proposing a 2
framework that the licensing modernization framework project fits more neatly 3
into than it does within a more deterministic framework like 50, or 52.
4 There's a lot in Part 53 that builds on prior work of the 5
Commission and the staff that is currently found in policy statements and 6
regulatory guidance. But I believe the Committee and the Commission should 7
think long and hard whenever it's considering whether methods that have 8
historically been acceptable in guidance should be codified in regulations.
9 Codifying those methods may sounds simple, but may create 10 significant complications, not the least of which is how to manage needed 11 modifications that may arise in the future. There will also be lost flexibility, and 12 lost opportunity for developing innovative methods that may differ from that 13 approach. Similarly, codifying policy statements should not be taken lightly.
14 We can assume that there were very good reasons why prior 15 commissions chose to address these issues as policy statements at the time.
16 Codification of safety goals is a prime example of this. In February, the ACRS 17 Subcommittee on Regulatory Policies and Practices was briefed on the 18 quantitative safety goals. The briefing noted that they were not considered to 19 be absolute or viewed in isolation, and that there may be excellent reasons to 20 allow operation above a goal.
21 That thought has been a consistent Commission policy since 22 adoption of the safety goals. The practical ramification of codifying the safety 23 goals would be to set a more stringent standard for advanced reactors than we 24
58 have for the currently operating fleet, contrary to the repeated Commission 1
direction in both SRM-10-0121, and again more recently in SRM-19-0117.
2 As I understand it, the ACRS reviewed, and made 3
recommendations to the Commission at the time that were consistent with what 4
was issued, particularly with regard to the QHOs not being intended to be 5
absolute requirements enshrined in regulation. Our reliability principle of good 6
regulation states once established, regulations should be perceived to be 7
reliable, and not unjustifiably in a state of transition.
8 So, reflecting on the response to Commissioner Baran's 9
question, what is a compelling justification for the Committee to depart from this 10 longstanding agency opposition as opposed to using, or directing effort toward 11 other surrogates? Dr. Petti?
12 DR. PETTI: So, as I understood it, surrogates were allowed 13 in the guidance that's there, that they can be innovative, and come up with 14 different ones. We had raised, in one of our letters, concern about the 15 applicability of the existing surrogates because they don't fit well. But this may 16 be a case where there's differing guidance in the agency.
17 Because there's numerous reg guides and SECYs that talk 18 about the qualitative health objectives being used; it's in NEI 18-04, it's in the 19 non-PRA standard, and the like. And that may be reflected, there may be a 20 time component here, right? When it was initially developed, now you look 21 back on it and reflect on where you are today, and how helpful it's been with the 22 current fleet, and then try to project to the future.
23 COMMISSIONER CAPUTO: But the examples that you 24
59 mentioned, aren't those enshrined in guidance, not rulemaking text?
1 DR. PETTI: Yes, they're in guidance, in the SECY, which is 2
policy, I'm not --
3 COMMISSIONER CAPUTO: Right. So, the justification for 4
putting them into rule text is a lack of identifying something else.
5 DR. PETTI: No, I think one of the other issues, which we 6
haven't touched about is, I think a public perception issue. That it could be 7
seen as the NRC moving away from those goals which are important.
8 COMMISSIONER CAPUTO: Well, if they are currently in 9
guidance, and would stay in guidance, that doesn't sound like much of a 10 justification for shifting them into rule text, they're not going away.
11 DR. PETTI: Well, but you wouldn't have to, if they're in 12 guidance, you wouldn't have to meet them. And I would -- I don't know why 13 we'd want an advanced reactor that was less safe than the existing fleet in 14 terms of where they sit relative to the QHOs.
15 COMMISSIONER CAPUTO: But the implementation of the 16 QHOs in rule text for advanced reactors sets a far more stringent safety level, 17 and that's --
18 DR. PETTI: I disagree. I think these advanced reactors, if 19 they're designed well, will have ample margin to the goals. None of them that 20 we have seen I think will be so close. There should be significant margin when 21 the numbers are done.
22 DR. REMPE: And the tabletops reflect that.
23 DR. PETTI: And the tabletops I think reflect that.
24
60 COMMISSIONER CAPUTO: So, is that really a justification 1
for shifting away from a longstanding agency position, though?
2 DR. PETTI: The argument for putting it in the rule has more 3
to do with having a metric to assure an equivalent level of safety to what's there 4
in 50 and 52. That, without it, there's a hole, and the staff might feel compelled 5
to put in additional requirements that could be -- well, that, A, could be more 6
difficult to make a technology neutral as such.
7 COMMISSIONER CAPUTO: But, part of the discussion 8
earlier, wouldn't it be simpler to use something like the PAGs rather than the 9
QHOs? Because as I mentioned in my remarks, there are ample justifications 10 for operating beyond the QHOs.
11 DR. PETTI: I think the staff wanted to give flexibility to 12 developers. Because the PAGs are a more restrictive set of requirements, it's 13 basically one to five REM at your site EPZ, which is usually the site boundary, 14 that's much more restrictive than the QHOs, but if they meet them, then it gives 15 you some assurance you can meet the QHOs.
16 COMMISSIONER CAPUTO: Well, I definitely don't think I 17 agree with you on whether the QHOs are less restrictive, or more restrictive. I 18 believe them to be far more restrictive. I also believe them to be incredibly 19 complicated when it comes to compliance space, and having to meet those on 20 a day by day basis, and the nature of how to prove that.
21 DR. PETTI: I would say that the current fleet meets the 22 QHOs with good margin, but cannot meet the EPA PAGs at their site boundary, 23 which is why they have emergency planning. So, the advanced reactors should 24
61 be able to meet the PAGs, then implicitly meet the QHOs.
1 COMMISSIONER CAPUTO: So, then what purpose do the 2
QHOs serve if they need to meet the PAGs? If they can meet the PAGs, and 3
don't need anything more restrictive?
4 DR. PETTI: It's flexibility. Somebody may decide they don't 5
want to meet the PAGs at their site boundary for some reason.
6 COMMISSIONER CAPUTO: All right, well I think you, and I 7
certainly will have to agree to disagree on whether meeting the QHOs is 8
actually possible, and attractive. One last question, Dr. Ballinger, you 9
discussed the Committee's visit to the SHINE facility under construction in 10 Wisconsin, and the Committee's consideration of the staff, training, caliber, and 11 commitment.
12 That sounds more appropriate to an oversight role fulfilled by 13 NRC staff in licensing, and operation space. Isn't that kind of pushing the 14 boundaries of the Committee's role?
15 DR. BALLINGER: No. I think that we were in the process of 16 reviewing the application, and so anything that we can do to advance, and help 17 that review, I think is perfectly appropriate. Now, it turned out that that visit was 18 very instructive, and very useful in our review. I think it actually made it easier 19 to do the review.
20 And so, I think that that visit, and such visits that achieve that 21 goal are the right thing to do. There may be cases where a visit to a plant, or 22 some site just simply doesn't add value to the review process, but in this case, I 23 personally believe, and I think that our other members would agree that the visit 24
62 did add very significant value, and probably shortened the review process.
1 COMMISSIONER CAPUTO: Well, I don't doubt that the visit 2
was very helpful. It's just the observation about evaluating staff during the visit 3
gave me pause.
4 DR. REMPE: If I could help? I would like to --
5 DR. BALLINGER: Are you talking about the staff that was 6
with us?
7 COMMISSIONER CAPUTO: No, you had a bullet that there 8
were -- that during the visit the Committee evaluated the licensee's staff, and 9
made observations about their training, caliber, and commitment.
10 DR. BALLINGER: I'm not sure we were doing evaluations of 11 the facility staff. I would say that getting to know them, and their demonstrated 12 degree of knowledge of their plant, and their construction was very helpful. But 13 we weren't evaluating the staff. We were just -- I'm just acknowledging the fact 14 that they were very competent, and we observed that.
15 DR. REMPE: If I could supplement Member Ballinger's 16 response, one of the items I started to bring up when Commissioner Wright 17 queried him about the visit was we actually saw a mock up where the staff was 18
-- the SHINE staff would be training on how they would conduct some of their 19 actions, and as you may recall in the letter, we did mention how the human 20 actions, we had some questions about the repetitiveness, and that was very 21 helpful at least for me to see during that visit.
22 COMMISSIONER CAPUTO: Okay, thank you, I don't have 23 any other questions. Thank you, Chairman.
24
63 CHAIR HANSON: Thank you, Commissioner Caputo. We 1
have reached the end of our time together, thank you all very, very much.
2 Thanks to my colleagues for your insightful comments, and questions, and 3
thanks to the members of the ACRS, and thank you for your service to the 4
agency, and to the country, we really appreciate it very much, and thank you for 5
the good discussion today. With that, we're adjourned.
6 (Whereupon, the above-entitled matter went off the record at 7
11:53 a.m.)
8