ML20339A593
| ML20339A593 | |
| Person / Time | |
|---|---|
| Issue date: | 11/05/2020 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| Burkhart, L, ACRS | |
| References | |
| NRC-1204 | |
| Download: ML20339A593 (150) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Docket Number:
(n/a)
Location:
teleconference Date:
Thursday, November 5, 2020 Work Order No.:
NRC-1204 Pages 1-112 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1
1 2
3 DISCLAIMER 4
5 6
UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8
9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.
15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
19 20 21 22 23
1 UNITED STATES OF AMERICA 1
NUCLEAR REGULATORY COMMISSION 2
+ + + + +
3 680TH MEETING 4
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
(ACRS) 6
+ + + + +
7 THURSDAY 8
NOVEMBER 5, 2020 9
+ + + + +
10 The Advisory Committee met via 11 Teleconference, at 9:30 a.m. EST, Matthew W. Sunseri, 12 Chairman, presiding.
13 14 COMMITTEE MEMBERS:
15 MATTHEW W. SUNSERI, Chairman 16 JOY L. REMPE, Vice Chairman 17 WALTER L. KIRCHNER, Member-at-Large 18 RONALD G. BALLINGER, Member 19 DENNIS BLEY, Member 20 CHARLES H. BROWN, JR., Member 21 VESNA B. DIMITRIJEVIC, Member 22 JOSE MARCH-LEUBA, Member 23 DAVID PETTI, Member 24 PETER RICCARDELLA, Member 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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2 DESIGNATED FEDERAL OFFICIAL:
1 CHRISTIANA LUI 2
3 4
5 6
7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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3 A G E N D A 1
- 4. Regulatory Guide 1.200 Revision on Review and 2
Approval of New Methods for Light Water Reactors 3
4.1. Remarks from the Subcommittee Chairman 6
4 4.2. Presentation and Discussion with 5
Representatives from the NRC Staff and 6
Industry Representatives 7
7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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4 P R O C E E D I N G S 1
9:30 a.m.
2 CHAIRMAN SUNSERI: Good morning, I have 3
9:30, the meeting will now come to order. This is the 4
second day of the 680th Meeting of the Advisory 5
Committee on Reactor Safeguards.
6 I'm Matthew Sunseri, Chair of the ACRS.
7 I will now call the roll to verify quorum and to 8
ensure members are able to participate, starting with 9
Ron Ballinger.
10 MEMBER BALLINGER: Here.
11 CHAIRMAN SUNSERI: Dennis Bley?
12 MEMBER BLEY: I'm here.
13 CHAIRMAN SUNSERI: Charles Brown?
14 MEMBER BROWN: Here.
15 CHAIRMAN SUNSERI: Vesna Dimitrijevic?
16 MEMBER DIMITRIJEVIC: I'm here.
17 CHAIRMAN SUNSERI: Walt Kirchner?
18 MEMBER KIRCHNER: Here.
19 CHAIRMAN SUNSERI: Jose March-Leuba?
20 MEMBER MARCH-LEUBA: Yes.
21 CHAIRMAN SUNSERI: Dave Petti?
22 MEMBER PETTI: Here.
23 CHAIRMAN SUNSERI: Joy Rempe?
24 VICE CHAIRMAN REMPE: Here.
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5 CHAIRMAN SUNSERI: Pete Riccardella?
1 MEMBER RICCARDELLA: Here.
2 CHAIRMAN SUNSERI: Okay, great. We have a 3
quorum and everybody comes in loud and clear.
4 The Designated Federal Officer for this 5
meeting is Ms. Christiana Lui.
6 During today's meeting, the committee will 7
consider the following. They'll have a technical 8
presentation on Regulatory Guide 1.200 Revision on the 9
Review and Approval of New Methods for Light Water 10 Reactors.
11 Following that, we will continue with 12 preparation of reports, including preparation for our 13 Commission briefing.
14 A phone bridge line has been opened to 15 allow members of the public to listen in on 16 presentations and committee discussions. We received 17 no written comments or requests to make any oral 18 statements from members of the public regarding 19 today's session.
20 There will be an opportunity for public 21 comment, we have set aside time in the agenda for 22 comments from member of the public attending or 23 listening to our meeting.
24 Written comments may be forwarded to Ms.
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6 Christiana Lui, the Designated Federal Officer.
1 A transcript of today's open portion of 2
the meeting, with the exception of our report 3
preparations and the planning and procedure session, 4
is being kept, and requested that the speakers 5
identify themselves and speak with sufficient clarity 6
and volume so that they can be readily heard.
7 Additionally, participants should mute 8
themselves when they're not speaking.
9 And I'll just add a note here for those 10 listening in on the phone line. We've been having 11 some general problems with the phone line lately, so 12 we do have members of our staff monitoring the phone 13 line for its operability and performance. And just 14 because you can't hear us, don't assume that we can't 15 hear you. And we will take action promptly to restore 16 functionality, so that you can provide your comments 17 when prompted.
18 Members, any questions about today's 19 agenda or where we're going? Or any general comments 20 you would like to make? Okay. I hear none, so I will 21 now turn to Member Dimitrijevic to lead us in the 22 discussion on Reg Guide 1.200. Vesna?
23 MEMBER DIMITRIJEVIC: Thanks, Matt. Good 24 morning. So, on February 5 this year, we were briefed 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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7 by the staff and industry representatives about the 1
update to Reg Guide 1.200 Rev 2 being prepared for 2
public comments. But the ACRS Reliability and PRA 3
Subcommittee request the staff has come back to brief 4
the full committee after completing the public comment 5
process.
6 Greg Bowman, the Deputy Division Director, 7
Division of Risk Assessment, NRR, will kick off today 8
briefing on the proposed Reg Guide 1.200 update.
9 Greg, the virtual floor is yours.
10 MR. BOWMAN: Thank you, Vesna. So, as it 11 was mentioned, my name is Greg Bowman, I'm the Deputy 12 Director of the Division of Risk Assessment in the 13 Office of NRR. I'd like to start off by thanking the 14 committee in advance for their review and feedback on 15 our draft Revision 3 to Reg Guide 1.200.
16 Reg Guide 1.200 is foundational to the 17 agency's ability to ensure high confidence that PRAs 18 used in risk-informed applications are technically 19 acceptable for those applications. So, your feedback 20 on this revision is particularly important to us.
21 One of the key elements of the revision is 22 the establishment of a framework to enable peer 23 reviews to be used to adopt newly developed PRA 24 methods.
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8 The use of the PRA peer review process, as 1
opposed to NRC staff review and approval of the PRA 2
and associated methods, is a practice that the 3
Commission approved about two decades ago. Since that 4
time, we the staff have been endorsing peer review 5
guidance and consensus PRA standards to support PRA 6
peer reviews.
7 Staff and industry identified the need for 8
improvement in the peer review guidance with respect 9
to PRA methods based on some challenges we experienced 10 during NFPA 805 review several years ago.
11 The proposed revision to Reg Guide 1.200, 12 among other things, will address that area for 13 improvement by endorsing a revised NEI guidance 14 document, that's NEI 17-07, along with a set of 15 approximately 20 requirements that were developed by 16 the PWR Owners Group for peer reviews of new and 17 developed PRA methods.
18 Those two sets of documents, once endorsed 19 in the reg guide, will be to establish technical 20 acceptability of newly developed methods through peer 21 reviews.
22 Ultimately, our goal with this revision is 23 to further enhance the efficiencies gained from the 24 peer review process, while ensuring a technical 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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9 acceptable PRA and an appropriate level of NRC 1
oversight.
2 During our presentation, the NRC staff 3
will provide details on the revision and an overview 4
of how we addressed the comments that we received from 5
industry and from the public.
6 So, I'd like to thank you again and just 7
indicate we look forward to addressing any questions 8
or feedback from the committee. And with that, I'll 9
turn things over to Anders Gilbertson to kick off the 10 staff's presentation for us. Anders?
11 MR. GILBERTSON: Great. Thank you very 12 much, Greg. Good morning, everyone. Good morning, 13 full committee members.
14 My name is Anders Gilbertson. I am a 15 reliability and risk analyst in the Office of Nuclear 16 Regulatory Research Division of Risk Analysis. I'm 17 also the technical lead for Revision 3 of Regulatory 18 Guide 1.200. And related to those roles, I'm also the 19 NRC's program manager for the NRC's PRA Standards 20 Program.
21 So, I am joined this morning by Shilp 22 Vasavada, from NRR Division of Risk Assessment, as 23 well as Sunil Weerakkody, also from NRR Division of 24 Risk Assessment.
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10 And so, this morning, we'll be giving a 1
presentation to just explain the staff's progress and 2
where we are with our final version, our draft final 3
version of Reg Guide 1.200 Revision 3.
4 I just want to double-check, I believe I'm 5
still sharing my screen, you should be able to see the 6
slides. Is that -- can someone confirm?
7 MEMBER BLEY: The introductory slide is up.
8 MR. GILBERTSON: Okay. Thank you. Okay.
9 So, this morning's presentation, first, 10 we'll just, I'll briefly discuss the purpose, which 11 I've already sort of gone over.
12 We'll go over some background on the 13 history of this revision, what prompted it and some of 14 the interactions that we had with public. The changes 15 that were incorporated into Revision 3.
16 We'll also have a brief discussion of the 17 subcommittee members' feedback that we received back 18 in February of 2020.
19 Sunil will talk about the primary 20 regulatory driver for Revision 3 and what really 21 prompted this revision.
22 Shilp will go through and talk about the 23 public comments that were received and how the staff 24 resolved those public comments on Draft Guide 1362, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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11 which was published for public review and comment.
1 And then, at the end, I will, Sunil and I 2
will discuss the path forward for Revision 3, and 3
then, also, subsequent revisions of Reg Guide 1.200.
4 So,
- again, the purpose of this 5
presentation is just to brief the ACRS full committee 6
and solicit feedback on the staff's resolution of 7
public comments on the staff's proposed Revision 3 to 8
9 As Dr. Dimitrijevic mentioned, the staff 10 went to the Subcommittee on Reliability and PRA and 11 presented before the public review and comment period 12 and we were asked to return to the ACRS after we 13 received public comments and had resolved them. So, 14 that is our purpose here today.
15 So, just some background, some general 16 background on Regulatory Guide 1.200. So, Reg Guide 17 1.200 provides an approach for determining the 18 technical acceptability of a base PRA model that is 19 used in regulatory decision-making related to light 20 water reactors.
21 The acceptability of the PRA is determined 22 with respect to the scope, level of detail, the 23 conformance to the consensus PRA standard technical 24 elements, this is sometimes more colloquial referred 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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12 to as technical robustness, and also plant 1
representation, which relates to plant realism and 2
plant specificity.
3 So, this slide describes, this is slide 4
five, also, for anyone on the phone, this just 5
describes the overall paradigm of PRA acceptability 6
for light water reactors.
7 And Reg Guide 1.200 is the staff's vehicle 8
for endorsing consensus PRA standards and industry 9
guidance for light water reactors related to risk-10 informed decision-making. Accordingly, this paradigm 11 has been established, as was mentioned before by Greg, 12 decades ago.
13 The base PRA is developed consistent with 14 the requirements and the PRA standards. The base PRA 15 is peer reviewed against the requirements in the 16 consensus PRA standard. And then, the development of 17 the base PRA and the performance of the peer review 18 are both done consistent with the NRC staff position 19 in Reg Guide 1.200, so, as we've endorsed those 20 industry documents.
21 So, each of these elements relies on the 22 other for the purpose of demonstrating acceptability 23 of the base PRA for risk-informed decision-making.
24 Licensees or applicants use Reg Guide 1.200 to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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13 determine acceptability of their base PRA obviates the 1
need for an in-depth staff review of the base PRA by 2
NRC reviewers.
3 And so, in doing so, that allows the staff 4
to focus their review on key assumptions and areas 5
identified by the peer reviewers as being of concern 6
and relevant to the application under consideration.
7 So, Reg Guide 1.200 is not in and of 8
itself used to implement specific parts of the NRC's 9
regulations. Rather, it is a supporting regulatory 10 guide that is invoked by other application-specific 11 guidance documents, where the acceptability of the 12 base PRA is important to the decision under 13 consideration.
14 Okay. So, this next slide six just is, 15 I'm going to talk a
little more about PRA 16 acceptability and just how it relates to the 17 importance and reliance from the PRA for a specific 18 application.
19 The importance of the base PRA to a 20 decision is dependent upon how much the PRA is used.
21 Accordingly, if there's greater reliance on and 22 importance of the PRA, the more important the 23 acceptability of the base PRA becomes for that 24 application.
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14 So, for example, for applications such as 1
license amendment requests to implement your risk-2 informed tech spec for bravo program, the PRA is 3
heavily relied upon for that decision-making. And so, 4
PRA acceptability of the base PRA becomes very 5
important.
6 That recognizes that the application PRA 7
is derived from the base PRA and may have differences 8
based on decisions made by the licensee. But in the 9
end, we are looking at the acceptability of the base 10 PRA from which those application PRAs are derived.
11 On the other end of the spectrum, the PRA 12 is less important for decision-making related to 13 requests for risk-informed inservice inspection 14 programs and, therefore, it plays a lower role.
15 So, this is a, it is a spectrum and what 16 is shown here just shows a general level of reliance 17 on, for some of these applications, risk-informed 18 applications that are used by licensees.
19 MEMBER BLEY: Anders, this is Dennis Bley.
20 MR. GILBERTSON: Yes.
21 MEMBER BLEY: I think it might be helpful 22 for my colleagues if you could talk a little bit about 23 how you use the peer review when you're reviewing a 24 risk-informed application.
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15 And what I'm getting at is, once the peer 1
review is complete, that doesn't say everything is 2
perfect, there's a pretty healthy catalogue of things 3
that could be beefed up in different ways, and how do 4
you go back to that and decide where you need to dig 5
more deeply?
6 MR. GILBERTSON: Sure, absolutely. Yes, 7
I'll talk about that and I'll also invite Shilp and 8
Sunil to jump in if they feel appropriate.
9 So, when the peer review for a base PRA is 10 completed, like Dr. Bley mentioned, there will be any 11 number of perhaps findings and observations or what 12 they're called, or I guess facts and observations.
13 These F&Os, as they're more commonly 14 referred to, they can range in level of importance 15 from just something that relates to documentation, 16 something that was missing in the documentation, all 17 the way to something that's more substantially wrong 18 or that points to the fact that a requirement in the 19 consensus PRA standard may not have been met. In most 20 cases, those are often referred to as finding level 21 F&Os.
22 So, when that's completed, the staff 23 receives a report that articulates what those F&Os are 24 and the staff are given opportunities to review those 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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16 assessments, to help determine for those specific 1
areas where it might be of greater interest how is the 2
PRA is acceptable?
3 And the staff are able to go into and 4
submit requests for additional information to 5
interrogate the process and better understand why 6
something wasn't
- met, offering the licensees 7
opportunities to provide explanations, additional 8
explanations for why they might have a finding.
9 So, it is -- there is a back and forth and 10 the staff also are relying on the guidance in Reg 11 Guide 1.200, as well as previous reviews and such. Is 12 that helpful? Or, Shilp or Sunil, did you want to add 13 anything else?
14 DR. WEERAKKODY: Yeah, go ahead, Shilp, 15 please.
16 DR. VASAVADA: Sure, sorry, thanks. This 17 is Shilp Vasavada, I'm in the Division of Risk 18 Assessment in NRR. Just wanted to add a couple of 19 additional points to what Anders mentioned.
20 The licensee would submit these finding 21 level F&Os that Anders mentioned, along with 22 dispositions or resolutions for staff review when they 23 submit for staff review a particular risk-informed 24 application.
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17 The staff reviews the dispositions and 1
determines the appropriateness in the context of a 2
particular risk-informed application. It is not, you 3
can say that the review and decision is not across the 4
board for any risk-informed application.
5 The other point I wanted to mention was 6
that, I think Sunil is going to talk about it, there 7
is a process accepted by the staff called the 8
Independent Assessment Team Closure Review, which can 9
also come in and, again, that's a separate peer 10 review, close out the findings.
11 Basically, make a determination that they 12 were resolved in a technically acceptable manner to 13 take care of the technical deficiency that was pointed 14 out in the finding. And then, those findings are 15 closed and they don't need to be submitted then to the 16 NRC staff. Thanks.
17 MR. GILBERTSON: Okay.
18 MEMBER BLEY: Anders, that was helpful, 19 thank you.
20 MR. GILBERTSON: Okay, great. Great.
21 Okay. So, moving on to slide seven.
22 So, Revision 3 of Regulatory Guide 1.200 23 incorporates a number of changes, primarily, which are 24 related to the guidance for PRA peer reviews. As was 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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18 mentioned earlier, the main driver is going to be the 1
new NEI 17-07 Revision 2 guidance document on PRA peer 2
reviews for LWRs, as well as the PWR Owners Group 3
report that articulated the 20-some requirements for 4
assessing the acceptability of newly developed 5
methods. And we'll talk about that in more detail as 6
we go along.
7 So, these are the primary changes. There 8
were some other changes. For example, the staff added 9
a new appendix to endorse a code case for the 2009 10 ASME/ANS Level 1 LERF PRA standard. This code case 11 only related to seismic PRA requirements and so, 12 essentially, this is a set of alternative requirements 13 for performing the seismic PRA.
14 And so, the staff provided, back, I 15 believe it was 2017, an acceptance of the requirements 16 in this code case. And so, all the staff did here is 17 to pull that forward and bring that acceptance and the 18 staff positions into Reg Guide 1.200 Revision 3. So, 19 that is the -- it's something that was essentially a 20 rote process of just pulling that endorsement forward.
21 Some other changes. So, Reg Guide 1.200 22 Revision 3 also adopts some terms that were defined in 23 the PWR Owners Group 19027 report. These were terms 24 that were discussed through a series of interactions, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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19 some workshops that were held by the Owners Group and 1
the discussions, we came to an agreement on what those 2
terms meant. There was an understanding that they 3
needed to be more clearly defined for these processes.
4 So, that's additionally what's provided in here.
5 And
- then, also, there's a
set of 6
descriptions of hazards in Appendix Delta of 1.200 7
Revision 3. And this listing of hazard and their 8
descriptions are intended to be consistent with the 9
ASME/ANS 2009 Level 1 LERF PRA standard.
10 And, really, what that listing does is, in 11 going beyond what's in the Level 1 LERF PRA standard 12 from 2009 is that it provides those descriptions. It 13 really, it starts to describe and, in some ways, 14 define what is meant by some specific hazard that you 15 need to think about and consider as you perform your 16 base PRA.
17 I did want to point out that Reg Guide 18 1.200 Revision 3, it does retain the staff's 19 endorsement of ASME/ANS RA-Sa-2009, with the exception 20 of some of the terms and definitions that were 21 endorsed from the Owners Group report.
22 So, as we interacted with members of 23 industry in these workshops, developed those 24 definitions, when the staff sat down to endorse them, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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20 we understood and realized that we already had an 1
endorsement for similar definitions and terms in the 2
2009 standards.
3 So, that's the only change to the staff's 4
endorsement of the Level 1 LERF standard, is basically 5
just to say, for some specific terms, we're now 6
endorsing the definitions as they exist in the Owners' 7
report. Okay. And slide nine?
8 So, again, back in February 2020, the 9
staff briefed the ACRS Subcommittee on Reliability and 10 PRA, when we were preparing to go out for public 11 review and comment with the draft guide. It was a 12 very good, healthy discussion and there were several 13 issues that were brought up and discussed by 14 individual members.
15 And understanding that we didn't ask for, 16 the staff didn't ask for any letters, and recognizing 17 that individual subcommittee member's views and 18 perspectives are not, they don't speak for the ACRS.
19 Really, what the second bullet is trying to emphasize 20 is that the staff did not feel compelled to make any 21 changes before the formal public review and comment 22 period document had been published.
23 So, we were ready to move forward with 24 that, see what external stakeholders thought, and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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21 then, collect and assess all of those impacts. And we 1
did go through and review the transcripts from the 2
February meeting when we were reviewing public 3
comments as well.
4 So, with that, we're no on slide ten and 5
I'm going to hand off the presentation to Sunil 6
Weerakkody.
7 DR. WEERAKKODY: Yeah.
8 MR. GILBERTSON: Sunil?
9 DR. WEERAKKODY: Yes. Good morning, thank 10 you, Anders. Good morning to members of the committee 11 and all the parties. My name is Sunil Weerakkody, I'm 12 the senior level advisor in probabilistic risk 13 assessment in Office of Nuclear Reactor Regulations 14 Office of Risk Assessment. It's a pleasure to be here 15 today.
16 Anders mentioned a number of changes we 17 have made into the Regulatory Guide 1.200. I will be 18 focusing on what I would call the primary regulatory 19 driver that prompted us to work on this update on an 20 expeditious basis.
21 I will do so by talking about three 22 different things, how we identified an important gap 23 in the Revision 2 of Reg Guide 1.200 with respect to 24 peer reviews of newly developed methods in PRA and why 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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22 we thought it was very significant to close that gap, 1
specifically for more of the more recent applications 2
that a number of licensees have been adopting, we 3
called it Tech Spec 4b or TSTF-505, but that -- and 4
finally, I also want to explain how we have 5
strategized using Reg Guide 1.200 update to close that 6
important gap using the two industry documents that I 7
have noted here, the PWR Owners Group 19027 Revision 8
2 and NEI 17-07. Next slide, please, Anders.
9 So, what is this gap? Greg mentioned 10 this. This is important, for each technical element 11 in the AMSE/ANS LERF PRA standards, there are high 12 level requirements that are supported by what they 13 call supporting requirements.
14
- And, for
- example, if it is human 15 reliability or systems analysis, event trees, there's 16 a set of HLRs, or high level requirements, and 17 supporting requirements. And the peer review was, the 18 independent peer review was, use these when they 19 review licensees' PRAs.
20 The 2009 version of the ASME/ANS Level 1 21 LERF PRA standard, which we endorsed in Rev 2, does 22 not provide high level requirements or supporting 23 requirements for newly developed methods. And also, 24 there is no definition as to what constitutes an NDM, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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23 or newly developed method.
1 What we realized, I think what I say here 2
is I think for Dr. Dimitrijevic and Dr. Bley, they are 3
very familiar with this, when licensees start adopting 4
NFPA 805, that is the risk-informed alternative to 5
fire protection regulations, we had about half of the 6
licensees developing fire PRAs and unlike the interim 7
for PRAs, it was a new territory in that new methods 8
had to be created.
9 And what happened was, in the staff, 10 during the staff reviews, we realized that not having 11 these high level requirements or the supporting 12 requirements for the newly developed methods was 13 manifesting as inefficiencies.
14 The staff had to resort to the RAI 15 process, audits, number of calls and questions, that 16 was burdensome to both staff and licensees. So, 17 during that time frame, we started realizing that we 18 have an issue here, or gap, that has to be closed in 19 an efficient manner. Let's go to the next slide, 20 please.
21 I know Anders already showed you this 22 slide, but I think I am reusing this slide to find out 23 why the staff thought it was very important to address 24 this gap in an expeditious manner.
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24 If you look at, at the top of these 1
applications, what's called RITS-4b, what it does is, 2
once a licensee requests to adopt that initially and 3
we approve, the licensees can use numbers generated 4
from PRA models to change the allowable outage times, 5
as long as they maintain the quality of the PRA in a 6
manner that is acceptable to NRC, without having to 7
keep coming back to NRC.
8 So, that's a pretty important application 9
and that's why on this chart, we put it at the top.
10 So, we realized, and I believe the industry did agree, 11 that it is very important that we close this gap with 12 respect to newly developed methods, so that we and the 13 public can have continued high level confidence on the 14 peer review process, or the agency's activities with 15 respect to Tech Spec 4b. Next slide, please.
16 So, when we issued the first several 17 licensing approvals for people who wanted to take 18 advantage of RITS-4b, to address this issue, what we 19 did was, to the license condition that the company's 20 safety evaluation -- a license condition, just to 21 refresh your mind, is something that the licensee is 22 legally bound by -- we added the language I have shown 23 here, which is that any change in the PRA methods to 24 assess risk that are outside these approval boundaries 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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25 requires prior NRC approval.
1 So, in a very high level, this to a great 2
extent addressed the staff's concerns with the 3
acceptability. But when we look at our principles of 4
good regulations, which requires us to continue to 5
look for efficiencies using, when possible, inputs 6
from our stakeholders, we realized that we are not 7
really meeting some of those principles to the best 8
degree we can. If you can go to the next slide, 9
please.
10 So, the reason we were convinced that we 11 had room to improve in this area is because we already 12 had a Commission endorsed peer review process.
13 Now, at the risk of repeating a number of 14 information that Dr. Dimitrijevic and Dr. Bley are 15 extremely familiar, during the subcommittee meeting, 16 I spent about five-ten minutes going through these 17 different documents. I will not do that here, but I 18 think for the benefit of the full committee, I'm going 19 to take about two minutes here to give you the 20 background of how we established the peer review 21 process.
22 So, the Commission and the staff alignment 23 and endorsement of the peer review process really 24 began about, I'd say 2000, that's two decades ago, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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26 when we were publishing 10 CFR 50.69.
1 At that stage, the Commission realized 2
that it is very important to have a common 3
understanding with respect to PRA quality or 4
acceptability, in order to stabilized risk-informed 5
initiatives.
6 So, when the rule was being discussed by 7
the Commission, the then chairman, Commissioner Diaz, 8
he had a COMNJD which is titled Stabilizing the PRA 9
Quality Expectations and Requirements in September, 10 and that's dated September 8, 2003.
11 So, what happened was, during this 12 discussion, there were deliberation of primarily two 13 approaches that the Commission can adopt in order to 14 get the required quality and acceptability of the 15 PRAs.
16 One option is to have the licensee submit 17 their PRAs for a full review by the staff. And the 18 other option was to establish a peer review process, 19 which would enable the staff to liberate the industry 20 review sources and basically focus on the findings and 21 observations that were identified by the peer review 22 team.
23 And after a number of deliberations, the 24 agency decided, with the industry's support, that we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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27 will follow the peer review path. And then, what 1
follows was the PRA implementation plan, I have 2
provided the references here, 2004.
3 And since then, the staff practice has 4
been to issue Reg Guide 1.200, by endorsing different 5
versions of ASME/ANS PSA standards, together with the 6
guidance that NEI puts out.
7 Today, we will be talking about NEI 17-07, 8
but as Anders mentioned, there have been a number of 9
other NEI documents, such as NEI 00-02, NEI, I'm not 10 going to list them all here, but it has been 11 consistent practice of the agency to do so.
12 And on top of that, I think, with respect 13 to the regulations, when 50.69 rule was published in 14 November 2004, the rule acknowledged the peer review 15 process in the rule language itself.
16 So, the point here is to convey to the 17 full committee that the peer review process that we 18 are continuing to follow here is an established 19 process that has received Commission endorsement, as 20 well as it's something that the staff and industry has 21 enlisted over the 20 years.
22 The reason this is a very important point 23 is, we had a very important issue with respect to 24 closing the gap with respect to newly developed 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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28 methods. Our initial attempt to address that was 1
through a license condition, but we realized that that 2
is putting too much inefficiencies to staff and 3
resources, and we knew the solution would be trying to 4
liberate the peer review process. If you could go to 5
my last slide, Anders?
6 MEMBER BLEY: Sunil, may I interrupt you?
7 This is Dennis --
8 DR. WEERAKKODY: Yes.
9 MEMBER BLEY: -- Bley. I don't see that 10 any of you had a slide on this, so I thought I'd ask 11 you about it.
12 In the Part B, bravo, of the Reg Guide, in 13 talking about why you've done the revision, you say it 14 enhances guidance related to key assumptions and 15 sources of uncertainty, which is admirable, and it 16 refers us to C, Charlie, 332.
17 And when I go to Charlie 332, looking for 18 some real meat, it kind of says, make sure you 19 identify the key assumptions and sources of 20 uncertainty. And I -- two questions jump at me.
21 One, there isn't much meat there and what 22 are you really expecting people to do and how does 23 this revision help you? And I guess that's 24 everything, it --
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29 DR. WEERAKKODY: Yeah.
1 MEMBER BLEY: -- just doesn't seem to have 2
a lot of explanation here. So, go ahead.
3 DR. WEERAKKODY: So, thank you, Dr. Bley.
4 We'll take that as a feedback. I am going to give a 5
first response, and then I'm going to invite Shilp and 6
Anders to add if I make any errors or additional 7
information.
8 What we have done in this reg guide is, I 9
believe we had added, I don't have the draft guide 10 right in front of me right now, we have added a 11 definition as to what a key assumption and uncertainty 12 is. And that, I think is one of the drivers that we 13 are using to further clarify that issue.
14 Shilp, can you please, because I don't 15 have the document in front of me right now?
16 DR. VASAVADA: Yes. So, this is Shilp 17 Vasavada from the NRC staff again.
18 So, yes, Sunil mentioned, one of the items 19 that this draft guide, the reg guide does is clarifies 20 the guidance on identifying and dispositioning key 21 assumptions and associated uncertainty, especially 22 taking into considering the recent experience that we 23 have had with reviewing license amendments for 50.69 24 and challenges that were faced by both the staff and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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30 the licensees in determining what would constitute a 1
key assumption and source of uncertainty and how to go 2
about dispositioning that.
3 So, the changes made to this revision 4
clarify the, you can say the definition of key 5
assumptions and sources of uncertainty. And then, 6
there are guidance documents like, for example, NUREG-7 1855, which provide additional details on how to go 8
about dispositioning them in the context of a 9
particular application.
10 MEMBER BLEY: I'm going to drag you out a 11 little bit on this. My memory is that identification 12 of key assumptions and sources of uncertainty have 13 always, since the earliest days of the standard, been 14 required.
15 I assume, since you've tried to make it 16 more clear, I guess it all shows up in the 17 definitions, I went back and looked at those while you 18 were talking. You must have run into cases where 19 there was substantial disagreement, either in peer 20 reviews or by people doing PRAs, on what those things 21 meant. Can you say anything about that?
22 DR. VASAVADA: Sure. So, this is Shilp, 23 I'll take it, and then, I'll respond first, and then, 24 if anybody wants to add something, they can.
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31 So, as you mentioned correctly, there are 1
several supporting requirements in the ASME/ANS PRA 2
standard that deal with broad scope listing of all the 3
uncertainties and assumptions that are in the PRA.
4 And the peer reviews look at that, in their findings, 5
they provide that.
6 What Reg Guide 1.200 says is if you follow 7
the guidance in 1.200, then the staff can focus on two 8
items. One is any items of concern or technical 9
deficiency findings that the peer review identified.
10 And second is key assumptions and sources of 11 uncertainty.
12 And the, you can say the challenges that 13 were faced was going from that long list of 14 uncertainties and assumptions that every PRA would 15 have and that these standards says should be 16 identified, to distilling them or sort of putting them 17 into what are the key assumptions and sources of 18 uncertainty? How to identify them and then, how to 19 disposition them?
20 That filtration process was where there 21
- was, you can
- say, the need for additional 22 clarification and guidance and the various challenges 23 we faced, which resulted in the revisions that were 24 made to this draft guide. Was that helpful?
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32 MEMBER BLEY: I think that gets me partway 1
there. Thank you, that's pretty -- there's a lot of 2
things going on in the revisions here that seem that 3
anybody doing this kind of work ought to know and be 4
doing already, but it seems we do need clarification.
5 MR. GILBERTSON: And, Shilp, this is 6
Anders, if I could maybe just add an aside to what you 7
had said? Strictly speaking, key assumptions and 8
sources of uncertainty are related to risk-informed 9
application itself.
10 So, there's a reason why you don't see 11 that explicitly addressed in the ASME/ANS PRA Level 1 12 LERF PRA standard, because that standard is written 13 for the development and to facilitate the assessment 14 of a base PRA. And of course, your application PRA is 15 derived from your base PRA.
16 So, a key source of uncertainty or 17 assumption is effectively an assumption or source of 18 uncertainty that has the potential to impact the 19 application or the decision under consideration 20 related to that application.
21 So, I
just wanted to make that 22 distinction.
23 DR. VASAVADA: Thanks, Anders.
24 MEMBER BLEY: Okay, thanks.
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33 DR. WEERAKKODY: So, if I may, so I'm on 1
slide 15, titled Approach to Close the Gap in Reg 2
Guide 1.200 Revision 3.
3 First is PWR Owners Group 19027 Non 4
Proprietary Version Revision 2, publicly available.
5 It provides definitions and related to NDMs, related 6
to newly developed methods, and for definitions of PRA 7
maintenance, PRA upgrades.
8 And it also provides six high level 9
requirements and 21 supporting requirements for peer 10 review of newly developed methods. They are being 11 considered for inclusion in the next edition of the 12 ASME/ANS Level 1 LERF PRA standard.
13 We wanted to -- we are endorsing the 14 Owners Group guidance at this time, because we are, as 15 Greg and I mentioned, we need, this is important 16 regulatory need that we need to resolve expeditiously, 17 because we have a number of applications coming on 18 TSTF-505.
19 And we had a number of meetings with the 20 Owners Group, the staff, and the technical staff had 21 a lot of important discussions to get to a point where 22 we aligned on the wording on these high level 23 requirements and the supporting requirements.
24 The next document is NEI 17-07 Revision 2.
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34 In comparison to the requirements that are the high 1
level and the supporting requirements in 19027, 17-07 2
provide guidance on the process that the peer 3
reviewers must use to peer review newly developed 4
methods, in addition to other technical elements of 5
the PRA.
6 And we started reviewing this document at 7
least before I got, after I got involved for about two 8
years. I still remember during the first couple 9
meetings, we had like 72 comments. But we were able 10 to work with the industry and resolve all 72 of them 11 and get to a point where at least what we are 12 proposing at this time is to endorse this guidance 13 without any exceptions or clarifications.
14 Now, one last item that I want to add to 15 actually sort of set up Shilp for his presentation is 16 emphasis on the word to close as opposed to 17 disposition peer review findings related to NDMs prior 18 to using them in PRA models.
19 Earlier, based on Dr. Bley's request, we 20 provided some explanations with respect to how the 21 process work, what are the facts and observations are.
22 Now, one of the things we realized was that we are, 23 with respect to the methods, because they could have 24 potential high degree of impact, we are basically 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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35 taking a position that if after a peer review, then 1
the peer reviewers identify facts and observations of 2
the method, they must be closed as opposed to 3
disposition.
4 And the word close and disposition have 5
completely different meaning in the peer review land.
6 Close is where the licensee looks at the F&Os, and 7
I'll invite Shilp to correct me if I make any errors 8
here, close is the licensee would use one of two 9
processes, either by submitting it to NRC or use an 10 independent peer review process to make sure that the 11 finding has been properly addressed and it is done, 12 there's no more activity on that.
13 Whereas, disposition mean, it's simply 14 saying how you explain either how that particular 15 finding is not impactful for a particular application.
16 So, there's a big -- so, whenever you hear the word 17 close as opposed to disposition, they are two very 18 different things in the peer review.
19 What we have done for the NDM means we are 20 basically saying that your F&Os for the method, it has 21 to be closed. If you do not, they cannot be used, 22 unless the method developer uses a topical process or 23 something like that to get our review and approval to 24 approve the method.
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36 So, that's all I have. I think next up is 1
Dr. Vasavada. Just to mention that, unlike me, Dr.
2 Vasavada has significant experience in actual peer 3
reviews, audits, and review of the licensing actions.
4 So, thank you all. Any questions for me before --
5 okay.
6 DR. VASAVADA: All right. So, thanks, 7
Sunil. Once again, this is Shilp Vasavada and I'm in 8
the Division of Risk Assessment in NRR.
9 My portion of the presentation will 10 provide an overview to the full committee and the 11 audience on the public comments that we received on 12 Draft Guide 1362 and how the staff dispositions and 13 resolved them, including any changes that were made to 14 the reg guide.
15 DG-1362 was released for public comment on 16 the first of July of this year, for a 30-day comment 17 period that ended on the 31st of July. In total, we 18 received 19 public comments from three external 19 stakeholders, the NEI, PWR Owners Group, and an 20 individual member of the public.
21 Just wanted to clarify that there were 19 22 comments in total, but that does not mean that there 23 were 19 unique comments. There were comments that 24 were similar to each other, and that's why there were 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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37 19 total and not 19 unique.
1 The public comments from NEI and the PWR 2
Owners Group, or PWROG, also included their responses 3
to two questions that were posed in the Federal 4
Register Notice. These questions related to the need 5
for explicit guidance in the reg guide on the closure 6
of peer review findings using an NRC-endorsed process 7
and the periodicity of such closures.
8 In addition, PWROG also submitted Revision 9
2 of the report 19027-NP, I'll just call it 19027 10 Revision 2 for simplicity.
11 So, that's a summary of what we received 12 through the public comment process. In the remainder 13 of the presentation, I'll provide a synopsis and 14 include the synopsis of the prominent public comments 15 that were received and a synopsis of how the staff 16 dispositioned them. I'll start with the comments that 17 resulted in changes to the reg guide. Next slide, 18 please.
19 So, for those who are following on the 20 phone, this is slide 17. And for the remainder of my 21 presentation, you'll see this structure for the 22 slides. On the left, you will see the synopsis of the 23 comment. And as I said, it's a synopsis, it's not the 24 entirety replicated over here. On your right, you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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38 will see the synopsis of the change that was made to 1
the draft guide. At the end of each slide, I'll pause 2
for any questions.
3 I'll start off with a few public comments 4
that were related to the consideration of peer reviews 5
for PRAs that credit planned modification, that is 6
modifications that are planned at the facility or 7
plant, but are not completed.
8 The NRC staff agreed with the comments 9
that guidance on consideration of peer reviews for 10 such cases was beneficial in the reg guide. And in 11 response to the comment, the NRC staff did add 12 clarifying guidance for PRAs of operating plants that 13 credit planned modifications.
14 The guidance states that the NRC staff 15 considers such cases to be special circumstances and 16 will address them on a case-by-case basis. In 17 addition, the guidance also, the additional guidance 18 that was included also states that the peer review and 19 submittal documentation should clearly identify and 20 describe such planned modifications and design 21 changes.
22 Any questions, comments? Okay. Next 23 slide, please.
24 MEMBER DIMITRIJEVIC: Sorry. Sorry, again, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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39 I have a problem with my button. This is Vesna 1
Dimitrijevic. My question here is, does that mean the 2
PRA used already incorporates the planned 3
modification, even the modification was not executed 4
yet?
5 DR. VASAVADA: So, the short answer is yes.
6 The peer review of that PRA would consider the planned 7
modification, which is not completed yet. And if such 8
a PRA is used to support an application, then that 9
will be the case, which is why that additional 10 clarifying guidance was added that staff would address 11 it on a case-by-case basis and the documentation 12 should clearly identify such a case.
13 DR. WEERAKKODY: Vesna, just to add a 14 remark there. This happened during 805 reviews.
15 Licensees would commit to certain modifications and 16 wanted to take credit for those.
17 And that, what we do was if the license 18 imposes, when we, if we give credit to such, we write 19 what we call license conditions to make sure that if 20 the PRA is applied for uses that they need to factor 21 that in, because they want to make sure that what they 22 committed to as part of the modification has been 23 implemented before using that PRA. Just wanted to 24 share that with you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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40 DR. VASAVADA: Thanks, Sunil.
1 MEMBER DIMITRIJEVIC: Well, I understand 2
that this would be very applicable to 805, but for 3
certain when it comes to the risk-informed completion 4
time, then the PRA has to reflect the current status 5
of the plant, right?
6 DR. WEERAKKODY: We fully agree and that's 7
how it will be done. It will be -- they have to use 8
the as-built as-designed plan if they are changing 9
anything, yes.
10 MEMBER DIMITRIJEVIC: Okay, all right.
11 Thank you.
12 DR. VASAVADA: And this is Shilp, just to 13 add clarity to that, I mean, what Sunil mentioned is 14 absolutely correct.
15 When the staff is reviewing such a case 16 where a planned modification is being credited, 17 definitely the impact of that modification on that 18 particular application will be considered and if it is 19 important to the staff decision, as Sunil mentioned, 20 there are ways in which the staff can ensure that 21 modification and the staff decision continue to be 22 valid when the program is implemented.
23 MEMBER DIMITRIJEVIC: Okay, thank you.
24 DR. VASAVADA: All right. So, maybe, any 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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41 other questions? Otherwise, I can move to slide 18.
1 Okay, thanks.
2 So, a public comment suggested correcting 3
the definition of PRA acceptability in the draft guide 4
by adding context. The context being that PRA 5
acceptability is related to the specific risk-informed 6
application and regulatory decision that is being 7
supported by the PRA.
8 The staff agreed with the comment that 9
context was indeed necessary for the definition of PRA 10 acceptability and has changed the definition of PRA 11 acceptability in the reg guide.
12 Specifically, the definition was changed 13 to state that PRA acceptability is determined for each 14 risk-informed application, considering the staff's 15 positions in Reg Guide 1.200, in any application-16 specific regulatory guidance, and any requirements for 17 that particular risk-informed application.
18 Any questions or comments? All right.
19 Anders, can you please go to slide 19?
20 One of the public comments that was 21 received suggested clarification on when a peer review 22 of a PRA upgrade was to be performed. The comment 23 stated that the driver for the peer review of an 24 upgraded PRA was the actual use of a PRA in a risk-25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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42 informed application.
1 And the NRC staff did agree with the 2
comment and, consequently, added clarifying guidance 3
to the reg guide. The additional guidance that was 4
included states that the peer review of a PRA upgrade 5
should be performed prior to the use of the PRA model 6
in support of an application, and an application can 7
be either an approved risk-informed program or the 8
submittal to the NRC staff for review.
9 Further, the staff also clarified that it 10 considers a newly developed method, the use of a newly 11 developed method in a PRA to be a PRA upgrade, because 12 it meets the definition of an upgrade in the reg 13 guide.
14 MEMBER DIMITRIJEVIC: Okay. This is Vesna 15 Dimitrijevic again. I would like just some 16 clarification in this case.
17 DR. VASAVADA: Yeah.
18 MEMBER DIMITRIJEVIC: So, let's say that 19 somebody who has already implemented risk-informed 20 inservice inspection, has applied the new method, and 21 therefore, performed the PRA upgrade. Since he 22 already has ongoing risk-informed application, does 23 that mean that he should perform the peer review 24 immediately?
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43 DR. VASAVADA: So, I think -- should 1
perform peer review immediately? Are you asking that 2
3 MEMBER DIMITRIJEVIC: I mean, immediately, 4
like is he expected to perform the peer review --
5 okay. So, what would be expectation -- okay. Most of 6
the plants in United States have incorporated risk-7 informed ISI.
8 So, and a lot of them, that will go 9
through this PRA upgrade. So, because the methods 10 change, finishing the thing. So, when they expected, 11 since they already have ongoing approved risk-12 information application, when are they expected to do 13 the new peer review?
14 DR.
VASAVADA:
So, from a
timing 15 perspective, I think that would be left to the 16 discretion of the licensee. From an expectation of 17 when the upgraded PRA is used, it would be that the 18 peer review should be performed prior to the use of 19 the upgraded PRA in the application.
20 MEMBER DIMITRIJEVIC: But that's -- it's 21 already used, they already have a risk-informed 22 program in place, that's what my question is.
23 DR. VASAVADA: Right.
24 MEMBER DIMITRIJEVIC: They already have a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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44 new inspection program in the place. And it's risk-1 informed program.
2 DR. VASAVADA: So, maybe I can explain with 3
an example. So --
4 MEMBER DIMITRIJEVIC: Okay.
5 DR. VASAVADA: -- let's say they have a PRA 6
right now, as you are saying, they're using it for a 7
risk-informed ISI and they do an upgrade, then they 8
can continue to use the current PRA for their 9
particular program.
10 If they would like to use the upgraded PRA 11 in that program, then a focus on peer review and 12 dispositioning of the findings should be performed 13 prior to using the upgraded PRA. So, until that is 14 done, they can continue to use what they currently 15 have, the non-upgraded PRA, in the program. Does that 16 help?
17 MEMBER DIMITRIJEVIC: That helps, it's just 18 really something which would be questionable, what if 19 the updated method resulted in significant difference 20 in the results or -- that's a very -- this is a very 21 interesting question, when you are processing, you 22 have any risk-informed application approved in one 23 moment and then your PRA developing and they may be 24 significantly changing. How do you retrofit this?
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45 DR. VASAVADA: I think, so, let me give my 1
thoughts and, Sunil, maybe you can --
2 DR. WEERAKKODY: Yeah.
3 DR. VASAVADA: -- help me. So, as I 4
mentioned, the PRA configuration control process 5
handles changes to the PRA, including updates and 6
maintenance. And at the end of that, there can be a 7
new version of the PRA or revision of the PRA, which 8
going forward can be used.
9 If there are changes, then, yes, that 10 would be something that would be within the licensee's 11 ability to change in the construct of that program.
12 Until that happens, the licensee is definitely allowed 13 to also be using the non-upgraded PRA for its 14 decisions.
15 Sunil, do you want to add anything?
16 DR. WEERAKKODY: Yeah. I believe I 17 understand the context of the question, and I'll 18 basically take a different example.
19 Let's say a licensee has decided that they 20 can use their PRA to change the surveillancing total 21 time of a particular component from one to three 22 months using a particular PRA, okay? And subsequent 23 to that, they do an upgrade to the PRA.
24 And the question would be, okay, you have 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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46 upgraded the PRA, but now we have a different PRA 1
model you could be using. I think what we are saying 2
here in this guidance is, before we use that updated 3
PRA going forward for a different application, for the 4
next change to the surveillance interval, clearly, 5
they have to get that peer reviewed, right?
6 But I believe Vesna's question is, what 7
about the changes that they have implemented? They 8
have already implemented, used this PRA that changed 9
for something else that they have already decided.
10 And a high level way to answer that 11 question from a safety standpoint, Dr. Dimitrijevic, 12 is that there is always, it's written into their 13 license conditions that when they make a change to the 14 PRA, they are required, the licensee is required to 15 make sure some of those changed parameters that was 16 used by using PRA remain still acceptable. That's the 17 expectation of the licensee.
18 Now, but to your point and the question, 19 we are not saying that would necessarily require you 20 to go and do another, quickly do an upgrade. But 21 that's something that -- and I think you got to bring 22 a little bit of the practicality into this.
23 Generally, these upgrades are, they could change the 24 numbers, but more often than not, they are not 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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47 impactful on things like the STIs unless there is 1
significant change.
2 If there are, the licensee is required by 3
the license conditions and the configuration control 4
that they built into the tech specs to make sure that 5
those parameters stay acceptable. So, that's the best 6
answer I can give.
7 But I think we should say that there is no 8
requirement, just because that PRA has been used in 9
the past applications to go and do peer review. The 10 requirement is that the changes that they have made to 11 the plant remain acceptable.
12 MEMBER DIMITRIJEVIC: Okay. Well, thank 13 you, Sunil. That --
14 DR. WEERAKKODY: Hopefully that helps. It 15 may not be the perfect answer, but I think -- so, what 16 I'm saying is, from a practical standpoint, we've done 17 what is necessary for the safety, not necessarily, 18 when you look backwards, not necessarily by requiring 19 prompt peer review, but requiring the licensees to 20 make sure that the plant or the parameters they have 21 used using PRA remain acceptable.
22 MEMBER DIMITRIJEVIC: Okay. Well, my 23 question is more related to something which will be 24 coming in your next revision, for advanced plan when 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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48 even the applicants for design certification and --
1 DR. WEERAKKODY: Oh, okay.
2 MEMBER DIMITRIJEVIC: Yeah. They don't 3
have a formal risk-informed application, like --
4 DR. WEERAKKODY: Yeah, yeah.
5 MEMBER DIMITRIJEVIC: -- tech specs, but 6
they do use PRAs to make a lot of risk-informed 7
decision, for example, exemptions from the GDCs or 8
things like that. As the PRA is developing and 9
changing, before it gets finalized, should we look 10 back to reevaluate this risk-informed decision?
11 That was one of things I am sort of 12 struggling with and I was interest -- I mean, of 13 course the changes in operating plants are less 14 significant.
15 DR. WEERAKKODY: Yeah.
16 MEMBER DIMITRIJEVIC: Okay. All right.
17 Well, thank you for --
18 (Simultaneous speaking.)
19 DR.
WEERAKKODY:
Thank
- you, Dr.
20 Dimitrijevic. Great question to ask Anders when he 21 comes back to the committee on the advanced nuclear 22 non-light water reactor reg guide.
23 DR. VASAVADA: Yeah, thank you.
24 MEMBER DIMITRIJEVIC: Also applies for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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49 advance, it doesn't --
1 DR. VASAVADA: Yeah.
2 MEMBER DIMITRIJEVIC: -- advanced light 3
water --
4 DR. VASAVADA: Oh, yes, yes, yes.
5 MEMBER DIMITRIJEVIC: -- it doesn't have to 6
be non-light water reactors.
7 DR. VASAVADA: Okay. So, this is Shilp.
8 Thanks for that feedback, we'll definitely take that 9
when we are moving forward with the next revision.
10 So, maybe we can go to slide 20, for the next -- okay.
11 We received a couple of public comments 12 that suggested clarifying when the differences between 13 the 2005 and 2009 version of the Level 1 LERF PRA 14 standard should be identified in support of a license 15 amendment request.
16 In the version that was released for 17 public comment, there was no context and it appeared 18 that such differences would need to be identified for 19 all amendment requests.
20 The staff agreed with the comment that 21 clarity was necessary and, consequently, added 22 clarification that those differences need to be 23 identified and addressed only if the 2005 version of 24 the Level 1 LERF PRA standard was used to support the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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50 base PRA acceptability for an application.
1 Note that this comment, although some of 2
you may already know, applies primarily to the 3
internal events PRA model, because the 2005 version 4
did not have an internal fire or external hazard PRA 5
acceptability determination.
6 Any questions or comments on that? Next 7
slide.
8 There were a couple of comments that were 9
focused on Appendix Delta in Draft Guide 1362.
10 Appendix Delta is new in the draft guide and in the 11 planned Revision 3 of 1.200 compared to Revision 2.
12 Its intent is to provide clarifying guidance on 13 various external hazards when such hazards are being 14 considered for an application.
15 The comments pointed out that there may be 16 inconsistencies between Appendix Delta in the draft 17 guide and Part 6 of the 2009 version of the PRA 18 standard, which is being endorsed by this revision of 19 the reg guide.
20 So, after reviewing the comments as well 21 as Appendix D in the draft guidance, staff did agree 22 with the comment that consistency between Appendix D 23 and the 2009 version was necessary. And, therefore, 24 the staff has revised Appendix D to be consistent with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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51 Part 6 of the 2009 version of the PRA standard, as 1
endorsed in the reg guide.
2 MEMBER BLEY: Well, that raises a question.
3 This is Dennis Bley, again.
4 DR. VASAVADA: Sure.
5 MEMBER BLEY: And I assume your center of 6
expertise on hazards helped you, was involved in this.
7 When you did that reconciliation with the 2009 version 8
of the standard, did any hazard groups disappear? And 9
if so, what are they and is it reasonable that they 10 should disappear?
11 DR. VASAVADA: So, I'll maybe have to ask 12 Anders to help me out with this one, since he looked 13 at this in detail. Anders, can you please help?
14 MR. GILBERTSON: Sure. Yeah, thank you, 15 Dr. Bley. So, in the draft guide, there were some 16 hazards that were removed to achieve that consistency.
17 For example, one of them that comes to mind is the 18 heavy load drop hazard. I believe that there was 19 another external hazard. But, yes, the short answer 20 is yes, there were some that were removed.
21 The thrust of the comment was more related 22 to that Reg Guide 1.200 was kind of expanding the 23 level of consideration inconsistent with the 2009 24 standard and our endorsement thereof. So, I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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52 what we were really trying to do was make sure that we 1
weren't effectively expanding our endorsement of the 2
2009 PRA standard.
3 As far as Revision 4 of Regulatory Guide 4
1.200 is concerned, we are, the staff are going to 5
think about what additional hazards that may have been 6
pulled out, and for example, that exist already in a 7
table in NUREG-1855 Revision 1, and consider how to 8
bring those in and descriptions, et cetera, to use.
9 There is already some momentum in that 10 direction with the advanced non-LWR PRA standard that 11 is soon to be published. They have a similar listing 12 of hazards in one of the portions of their document.
13 And it is an expanded list.
14 So, ultimately, the main thrust is that we 15 were not -- we didn't want to expand the staff's 16 previous endorsement.
17 MEMBER BLEY: Well, I'm concerned about 18 that one. The whole idea in PRA is to get a complete 19 set of events and if we leave some out and discover 20 that, we need to keep adding them. That's part of the 21 process of being consistent.
22 It isn't a good reason to ignore new 23 things we've learned and I'm kind of nervous about 24 this, I'd probably lean toward sending you guys a note 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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53 that expressly identified this.
1 I'd like -- well, I can go back and check 2
for myself to see what disappeared, in addition to 3
heavy load drop. We know that's a potential event and 4
it's been analyzed in PRAs over the last 30-40 years, 5
in cases where it turned out to be a significant 6
possibility.
7 This one does bother me. I'll have to 8
think about that a little bit. And I'm glad you're 9
picking it up elsewhere, but this -- having a reg 10 guide, although it's for the public, but also is used 11 by the staff and if we're taking away things they 12 ought to be considering and looking at, we're leaving 13 it up to their creativity, which we want them to have, 14 we don't want to cut things out intentionally.
15 So, that's a bit of a troublesome one for 16 me. But, go ahead.
17 MR. GILBERTSON: If I could, and this is 18 Anders Gilbertson, if I could just add on to that? I 19 certainly appreciate the concern and I think the staff 20 more broadly also appreciate the concern.
21 I guess, this isn't to try and alleviate 22 that concern, but I would point out that that listing 23 is, at least in the Level 1 LERF PRA standard, it's 24 not a mandatory list. So, it's actually in a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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54 nonmandatory appendix. So, in that way, it's 1
presented as a large list of hazards that need to be 2
considered, but it's not exhausted.
3 So, as the PRA technology and lessons 4
learned have evolved and we've gotten more insights 5
about what is and what is not potentially important to 6
consider, for example, there is a NUREG on heavy load 7
drops that analyzes that, Shilp and Sunil could maybe 8
correct me, but I believe there are some licensees who 9
have done heavy load drop PRAs, perhaps not many, but 10 I believe some have been done.
11 But, anyways, again, the concern is, I 12 fully acknowledge that and appreciate that.
13 MEMBER BLEY: It's, I'm glad you added 14 Appendix D, it's a pretty darn thorough list, but the 15 idea that we edit such a list is troublesome, because 16 although every analyst and reviewer should think 17 expansively and see what might have been left out, if 18 we purposefully cut down on the things we tell them to 19 think about, that increases the chance that something 20 important is missing.
21 And, I guess, this is for Vesna. I'm a 22 little inclined that we ought to say something about 23 this, Vesna. But let's --
24 MEMBER DIMITRIJEVIC: But it --
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55 (Simultaneous speaking.)
1 MEMBER DIMITRIJEVIC: I thought about this 2
too, but in my opinion, it also applies more for the 3
next revision, which is for the new plants. Because 4
this revision, in my opinion, is for operating plants 5
and most of them have completed their PRAs and peer 6
reviews and now, they're doing just upgrades and 7
things like that.
8 So, I think we should get a chance to look 9
in this again in details for Rev 2, which will apply 10 for the new PRAs and applications.
11 MR. GILBERTSON: And --
12 MEMBER BLEY: Let's get --
13 (Simultaneous speaking.)
14 MEMBER BLEY: So, when do you expect that 15 to happen?
16 MEMBER DIMITRIJEVIC: Yeah, we --
17 MR. GILBERTSON: Revision 4?
18 MEMBER DIMITRIJEVIC: Yeah, we have a 19 couple slides and then, I hope we will get to discuss 20 when do you expect this rev and things like that in 21 your last two slides.
22 MR. GILBERTSON: Yes, I'll be prepared to 23 speak to that.
24 MEMBER MARCH-LEUBA: Hey, this is --
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56 MEMBER DIMITRIJEVIC: Okay.
1 MEMBER MARCH-LEUBA: -- Jose March-Leuba.
2 I wanted to add my support to Dennis' position. And 3
you know by now my opinion on this. The Achilles heel 4
of risk-informed anything is calculating the risk.
5 And the way to calculate the risk is to calculate all 6
the risk of the individual components and add them up.
7 If you automatically remove components, 8
all you are doing is calculating a lower bound of the 9
risk. So, the risk could not possibly be smaller than 10 this, but it could be much larger.
11 So, I'll keep it here, but I support 12 Dennis' position. I mean, I don't see any absolute 13 reason or justification to remove hazards.
14 DR. WEERAKKODY: Yeah, and this is Sunil 15 Weerakkody. I think we heard, I think two members of 16 the committee. So, let me just say that I think we 17 understood your comment, we are going to take a 18 serious look at that feedback and definitely -- I'm 19 writing that down as a followup item, to come back to 20 you.
21 MEMBER BLEY: You do --
22 DR. VASAVADA: Sunil --
23 MEMBER BLEY: You do say that it's a 24 minimum list of hazards in the text, but the tables 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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57 themselves, which is often where people go without 1
carefully reading all the text, don't say this is a 2
partial list, a minimum list, an example list, they 3
say this is the list.
4 So, maybe you could do something at least 5
editorial to say this is not complete and everybody 6
needs to be thorough in their own analyses. But I 7
really can't see reasons for dropping things just to 8
be consistent. Go ahead.
9 DR. WEERAKKODY: Yes, sir. I mean -- this 10 is Sunil Weerakkody again. We agree that it's 11 something that we need to go back and take a look at.
12 DR. VASAVADA: This is Shilp Vasavada from 13 the NRC staff. I just wanted to add one additional 14 item, that for, at least from a licensing perspective 15 and the staff reviews licensing applications, 16 licensees do have to address these external hazards 17 and how they are considering them. That is also part 18 of the regulatory guidance in 1.174. And demonstrate 19 either that they don't have an impact on the 20 application or treat them either qualitatively or 21 quantitatively.
22 So, from a perspective of risk-informed 23 applications, they are considered and the staff does 24 look at them --
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58 MEMBER BLEY: Okay.
1 DR. VASAVADA: -- as well as the licensees.
2 MEMBER BLEY: There's always a rule that 3
says, gee, because you missed this, you broke our 4
rule. And if you ever followed safety in the railroad 5
business, you'd know that there were rules for 6
everything, that you couldn't even drive a train 7
without violating the rules, so they could always 8
blame the engineer or conductor for every accident.
9 If we're going to give guidance, it's 10 guidance, it's to help people meet the rule, be more 11 likely to meet the rule in a good way. So, yeah --
12 DR. WEERAKKODY: Yeah --
13 MEMBER BLEY: -- everybody's responsible to 14 do a thorough job on their own, but if we're trying to 15 help them out, we shouldn't limit how we help them.
16 DR. WEERAKKODY: Yeah, we tend to, at least 17 speaking for myself, this is Sunil again, I think we 18 heard -- I think you're making a great point. And 19 regulatory guidance is guidance.
20 If we add a couple additional external 21 events, again speaking for myself, that's not 22 necessarily mandating by a rule that every licensee 23 should or shall. It's simply saying that, hey, 24 consider this also as part of your thinking.
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59 So, in that construct, I think we need to 1
take back your feedback and reflect on that as staff, 2
and we'll definitely get back to you.
3 MEMBER BLEY: I --
4 DR. WEERAKKODY: Thank you.
5 MEMBER BLEY: I know you don't want to make 6
any major changes --
7 DR. WEERAKKODY: Yeah, yeah.
8 MEMBER BLEY: -- so, maybe think about this 9
for the next round. One way --
10 DR. WEERAKKODY: No, I --
11 MEMBER BLEY: One way that helps in a list 12 like this is to group them by similar items --
13 DR. WEERAKKODY: Yeah.
14 MEMBER BLEY: -- so you've got the whole 15 space covered and then --
16 DR. WEERAKKODY: Yeah.
17 MEMBER BLEY: -- you give examples of what 18 things fit under each of the --
19 DR. WEERAKKODY: Yeah.
20 MEMBER BLEY: -- higher level categories.
21 But go ahead.
22 DR. WEERAKKODY: Yes. Thank you, Dr. Bley.
23 DR. VASAVADA: Thank you for that feedback.
24 All right. So, if there's nothing more on this slide, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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60 we can go to the next one, slide 22 and the next 1
public comment or comments.
2 So, in the draft guide that went out for 3
public
- comment, the staff had identified one 4
clarification to Revision 2 of NEI 17-07. The 5
clarification related to the documentation of the 6
resolution of peer review findings.
7 In one of its public comments, NEI 8
identified existing text in 17-07 Revision 2 which, 9
again, according to the comment, addressed the 10 clarification that was identified by the staff. After 11 reviewing the cited text and the clarification, the 12 staff agreed that the text indeed addressed the 13 clarification, and that's why we have removed the 14 clarification from the reg guide.
15 Similarly, the draft guide that went out 16 for public comment identified two clarifications on 17 19027 Revision 1. One of the clarifications was 18 regarding the PRA upgrade determination process.
19 As part of its problem comments, the PWROG 20 submitted Revision 2 of 19027. And after review, 21 staff determined that the items that resulted in the 22 clarification were actually removed from Revision 2.
23 Based on its review of Revision 2
and the 24 clarification, the staff did not see the need for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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61 continuing to keep that clarification and has removed 1
the clarification.
2 If there are no questions, we can go to 3
slide 23.
4 We received public comments on the two 5
questions proposed in the Federal Register Notice.
6 Again, to refresh the memory, these questions were 7
related to the need for explicit guidance on the 8
closure of open peer review findings using an NRC-9 endorsed process and the corresponding periodicity of 10 closure.
11 We received detailed response from the 12 PWROG and NEI on these questions. Based on our review 13 of the responses, the NRC staff agreed that the 14 closure of open peer review findings using an NRC-15 endorsed process should be a licensee's decision, 16 based on weighing the benefits of the closure against 17 the cost of the closure.
18 The staff does note that closure of 19 findings helps enhance PRA acceptability and reduces 20 resources for the staff and the licensee in licensing 21 activities and any potential oversight activities.
22 After reviewing the responses, the staff 23 did find it necessary to add clarifying guidance under 24 disposition of peer review findings from any peer 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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62 reviews, including those that were conducted after 1
approval of a risk-informed application.
2 The guidance that was added states that 3
findings from peer reviews should be evaluated for the 4
risk impact on risk-informed application and should be 5
addressed with documented justification and any 6
necessary changes to the PRA.
7 And all of these activities, the 8
evaluation, the justification, and the changes, should 9
be performed prior to the use of the PRA in a risk-10 informed application.
11 Any questions or comments on that? Okay.
12 We can go to slide 24.
13 So, in the previous slides, I kind of 14 provided a synopsis of the resolution of the public 15 comments that resulted in changes to the draft guide.
16 In this slide and the next, I'll discuss a couple of 17 comments that did not result in changes to the draft 18 guide.
19 There were multiple public comments that 20 were received related to the availability of Revision 21 2 of 1.200 after the issuance of Revision 3. The 22 concern in the comments was that licensees may have 23 received peer review guidance from Revision 2 for 24 technical acceptability activities and redoing the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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63 peer reviews using the guidance in NEI 17-07, which is 1
endorsed by Revision 3, or is expected to be endorsed 2
by Revision 3, would not add value.
3 As was previously noted, NEI 17-07 4
consolidates peer review guidance from different 5
documents which were endorsed in Revision 2. The 6
staff agrees that Revision 2 is not being withdrawn 7
and the staff's publicly available responses will 8
explicitly state that.
9 As a result, changes were not made to the 10 reg guide, which is consistent with reg guide 11 revisions, that is they don't carry information about 12 the availability or not of previous versions.
13 The staff response, publicly available 14 response will also clarify that the staff anticipates 15 one revision of the reg guide to be followed for a PRA 16 application and any deviations from the referenced 17 version that is used in the application, including the 18 use of any alternatives from previous versions, should 19 be identified and justified.
20 So, any questions or comments? Okay. We 21 can move to the next one.
22 Another public comment that did not result 23 in a change to the reg guide was about changing the 24 use of the term application to the narrower licensing 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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64 application throughout the draft guide. The comment 1
identified that not all applications need a full-scale 2
PRA acceptability review and that was the basis for 3
the suggested change.
4 The staff did not make changes to the reg 5
guide based on this comment for two reasons. Firstly, 6
the staff believes that term application is used in 7
1.200 consistent with the definition of the term PRA 8
application in the endorsed 2009 version of the PRA 9
standard. It was endorsed in the Revision 2 and it is 10 expected to be endorsed in Revision 3.
11 Secondly, the application-specific staff 12 positions on PRA acceptability exist in the 13 corresponding guidance. An example is the integrated 14 leak rate test guidance, where the level of detail and 15 plant representation at category one is considered 16 sufficient.
17 So, such application-specific guidance 18 addresses cases where full-scale PRA acceptability 19 review may be unnecessary.
20 Any questions or comments on that? Okay.
21 Then, that ends my overview of the resolution of 22 public comments on Draft Guide 1362 and the 23 corresponding dispositions by the NRC staff. Based on 24 the agenda, I will turn it over to NEI and PWROG for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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65 their perspectives, if that is the correct order.
1 MEMBER DIMITRIJEVIC: We have a couple more 2
slides in your presentation, path forward and two new 3
slides on that. Are we going to come back to those?
4 DR. VASAVADA: This is Shilp, I'm sorry, I 5
was going by the agenda and it stated that after my 6
portion of the resolution of public comments 7
discussion --
8 MEMBER DIMITRIJEVIC: Okay. We will --
9 (Simultaneous speaking.)
10 MEMBER DIMITRIJEVIC: Okay. That sounds 11 good. Okay.
12 DR. VASAVADA: Thank you.
13 MEMBER DIMITRIJEVIC: So, okay. So, we 14 will go to the industry, NEI and PWR Owners Group.
15 Who's going to be the first?
16 MS. ANDERSON: Yes, this is Victoria 17 Anderson with NEI.
18 MEMBER KIRCHNER: This is --
19 MS. ANDERSON: Oh, go ahead.
20 MEMBER KIRCHNER: Vesna, is this a good 21 time for a break? Is this a long presentation?
22 MEMBER DIMITRIJEVIC:
Both of those 23 presentations are short. But I think it maybe makes 24 sense, because we have a -- we are not so limited with 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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66 this 11:30 finishing, we are a little behind schedule, 1
but I think this is okay, maybe we can make a ten-2 minutes break in this moment. So, let's meet 11:15 3
then.
4 (Whereupon, the above-entitled matter went 5
off the record at 10:58 a.m. and resumed at 11:15 6
a.m.)
7 CHAIRMAN SUNSERI: Okay, members. It's 8
11:15. I will do a quick roll call just to confirm we 9
have a quorum.
10 First, Ron Ballinger?
11 MEMBER BALLINGER: Here.
12 CHAIRMAN SUNSERI: Dennis Bley?
13 MEMBER BLEY: I'm here.
14 CHAIRMAN SUNSERI: Charles Brown?
15 (No response.)
16 CHAIRMAN SUNSERI: Vesna?
17 MEMBER DIMITRIJEVIC: Here.
18 MEMBER BROWN: I'm sorry. Couldn't find 19 my mic. I'm here, Matt.
20 CHAIRMAN SUNSERI: Okay. Thanks.
21 Walt Kirchner?
22 MEMBER KIRCHNER: Here.
23 CHAIRMAN SUNSERI: Jose March-Leuba?
24 MEMBER MARCH-LEUBA: Here.
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67 CHAIRMAN SUNSERI: Dave Petti?
1 MEMBER PETTI: Here.
2 CHAIRMAN SUNSERI: Joy Rempe?
3 VICE CHAIRMAN REMPE: Here.
4 CHAIRMAN SUNSERI: Pete Riccardella?
5 MEMBER RICCARDELLA: Here.
6 CHAIRMAN SUNSERI: Okay. We have a 7
quorum.
8 Vesna, you may continue.
9 MEMBER DIMITRIJEVIC: Okay. So we will 10 have now the industry representatives from NEI and we 11 will start with NEI and then PWR Owners Group.
12 So Victoria, please -- the floor is yours.
13 MS. ANDERSON: All right. Thank you.
14 Good morning. This is Victoria Anderson 15 from the Nuclear Energy Institute and I will be 16 providing some reflections on the NEI perspective on 17 Reg Guide 1.200 Revision 3.
18 Okay. There we go.
19 So with respect to how we see Reg Guide 20 1.200 Revision 3
as supporting risk-informed 21 regulation, the peer review process itself has really 22 been an important part of implementation of the ASME 23 ANS/PRA standard since it came out.
24 We undertook an effort to improve the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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68 processes associated with it after over a decade of 1
experience. We published that in NEI 17-07.
2 Revision 3 specifically includes some 3
important updates to support regulatory stability, 4
specifically, with respect to finding closure and 5
newly developed methods, as was previously discussed.
6 Both of these items will conserve both industry and 7
NRC resources in the review of risk-informed 8
applications.
9 So we see the issuance of Revision 3 of 10 this Regulatory Guide as an important step in 11 supporting continued advancement of risk-informed 12 regulation.
13 I also want to take a minute to talk about 14 the Federal Register notice question to stakeholders, 15 which specifically read should licensees be required 16 to periodically close all their PRA peer review 17 findings to ensure confidence in the information used 18 in risk-informed programs.
19 As you heard from the NRC staff earlier, 20 there was not any language added to the Reg Guide with 21 respect to this. We provided a comment that we did 22 not support an addition to Regulatory Guide 1.200 and 23 it's for two reasons.
24 First, we think that the configuration 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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69 control criteria in the PRA peer review guidance 1
document are sufficient to ensure that high fidelity 2
information is used in support of risk-informed 3
applications.
4 The configuration control criteria are 5
evaluated as part of the PRA peer review and the NRC 6
has access to documentation relative to that in their 7
review of license amendment requests.
8 Our second reason is that we were not 9
aware of any specific regulatory concerns that would 10 have been addressed by such a requirement.
11 So, in other words, it was kind of a 12 solution in search of a problem and we didn't really 13 see that there would be any value added from this.
14 So we support the NRC's staff decision to 15 not include such language in Reg Guide 1.200 Rev 3.
16 That is all I have to offer on the NEI perspective on 17 Reg Guide 1.200 Rev 3.
18 MEMBER DIMITRIJEVIC: Okay. Do we have 19 any questions?
20 (No response.)
21 MEMBER DIMITRIJEVIC: All right. If not, 22 then we can proceed with PRW Owners Group 23 presentation.
24 Roy Linthicum from PRW Owner Group, I 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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70 think, is going to give that.
1 (Pause.)
2 MEMBER DIMITRIJEVIC: Is Roy here?
3 MR. MAIOLI: Hello. This is Andrea 4
Maioli. I'm just confirming that you can see the 5
slides.
6 MEMBER DIMITRIJEVIC: Yeah, we can see 7
slides.
8 MR. MAIOLI: Okay. Roy is supposed to 9
give the presentation. I just manage the slides here.
10 MEMBER DIMITRIJEVIC: Okay.
11 MR. WEERAKKODY: Roy, are you there?
12 (No response.)
13 MR. WEERAKKODY: Andrea, this is Sunil.
14 Perhaps you could present the slides if Roy is not 15 here. Maybe he has some technical difficulty or --
16 MEMBER BLEY: Or somebody could call him.
17 Yeah, I don't see him on the list.
18 CHAIRMAN SUNSERI: I don't see him on the 19 attendees roster right now.
20 MEMBER DIMITRIJEVIC: I see him on the 21 list. I saw the L on the top of the list. So I see 22 him on the list. His microphone is muted.
23 MR. MAIOLI: I can definitely go through 24 some of the slides unless -- unless -- well, we just 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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71 have a couple slides here. If needed. Just let me 1
know.
2 MR. WEERAKKODY: I will -- I will call Roy 3
to find out. Or, Andrea, what do you want to do? Do 4
you want to present the slides or you want to call 5
Roy? It's up to the Owners Group.
6 MR. MAIOLI: I can present the slides if 7
you want. Otherwise, give me a minute and I'll try to 8
call Roy.
9 MR. LINTHICUM: Good morning. Can you 10 hear me now? Oh, okay.
11 MR. WEERAKKODY: Yes.
12 MEMBER DIMITRIJEVIC: Okay. All right.
13 Okay. Okay. So you can proceed now with the slides.
14 (Pause.)
15 MS. LUI: Looks like Roy is having issue 16 with his microphone right now.
17 MEMBER DIMITRIJEVIC: Yes, he does because 18 he goes to muted again. So --
19 CHAIRMAN SUNSERI: His status is showing 20 offline.
21 MS. LUI: He was trying to reconnect and 22 make his mic work.
23 MEMBER DIMITRIJEVIC: I see. Okay. So 24 while we are waiting for Roy, I wanted to -- I can add 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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72 something to our previous discussion because when we 1
were talking about including the hazards in the PRA 2
and Jose made a comment that we are more conservative 3
if we include the concepts.
4 But because this Reg Guide applies to 5
risk-informed applications, actually adding hazards 6
reduce conservatism. Because what has happened if you 7
add the heavy load drop to the PRA like we had the 8
case that recently reviewed the PRA, that event will 9
dominate the risk measures.
10 So risk measures will be higher. However, 11 importance of anything else will be lower.
12 So adding hazards to the PRA actually 13 would -- can significantly reduce conservatism in 14 risk-informed applications.
15 So, for example, adding the heavy load, 16 which was not added to total from the different 17 reasons would make everything else, like, for example, 18 the ECCS valves not important because the load itself 19 will dominate risk -- risk measures and importance 20 using risk-informed applications are relative.
21 So they are measured to the total thing, 22 and if the total thing is dominated by the hazard then 23 the other things become less important. So from the 24 point of conservatism, adding hazards would not make 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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73 things -- you know, it will make them less 1
conservative.
2 MEMBER BLEY: But that's a kind of turned 3
around argument, Vesna.
4 MEMBER DIMITRIJEVIC: No. No. That's a 5
very well known argument. Sometimes you have to --
6 MEMBER BLEY: Well, if you got a big rock 7
it hides the other rocks. But there's no reason to 8
believe -- if there's -- if there's a reason to 9
believe one thing left out is dominant then you damn 10 well need to include it.
11 MEMBER DIMITRIJEVIC: Well, if your -- if 12 your goal is to -- if your goal is to report risk 13 measures, if your goal is to report risk metrics 14 that's a true statement.
15 But if your -- this is not for the 16 reporting to saying that we satisfy safety goal or 17 not. This is for risk -- this Reg Guide's approach to 18 the -- to the suitability of PRA for risk-informed 19 activities.
20 MR. MAIOLI: Okay. This is Andrea Maioli.
21 Sorry for interrupting --
22 MEMBER DIMITRIJEVIC: So did we get Roy 23 back?
24 MR. MAIOLI: I just wanted to let you know 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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74 that Roy texted me saying that he has been having 1
problems connecting. So he's asking me to go through 2
the presentation, if that's okay for you.
3 MR. LINTHICUM: Yeah. Actually, Andrea, 4
I think I'm resolved, if everyone can hear me now.
5 MR. MAIOLI: Okay. Okay. Yes, I can hear 6
you. Yeah.
7 MR. LINTHICUM: All right. Yes, sorry 8
about that. I was having some technical problems and 9
I had to switch devices. But that's all been resolved 10 now.
11 So I'm Roy Linthicum. I'm employed by 12 Exelon and I'm the -- but I'm on full time loan to the 13 Owners Group as chairman of the Risk Management 14 Committee for the PWR Owners Group and I'd like to --
15 I just have a very short presentation on our 16 perspectives related to Reg Guide 1.200 and newly 17 developed methods.
18 So, Andrea, can you go to the next slide?
19 MR. MAIOLI: Can you see the -- which 20 slide can you see right now?
21 MR. WEERAKKODY: I see slide one.
22 MR. MAIOLI: Oh, I'm showing the wrong 23 screen. Okay. Well, I'll go -- I'll go here.
24 MR. LINTHICUM: All right. There you go.
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75 Yeah. So, yeah, like as already been 1
mentioned, we do think that Reg Guide 1.200 Rev 3 does 2
clarify some long-standing issues related to advancing 3
new methods in PRA and really does provide a cost 4
effective process to take regulatory acceptance of new 5
PRA methods.
6 And as Victoria mentioned, with regard to 7
closure of peer review findings, and Sunil mentioned 8
this as well, we do feel it's appropriate to leave 9
that decision as far as closure to licensee 10 discretion.
11 That's both findings that were open at the 12 time we made the licensing -- a license amendment 13 request as well as any new findings related to 14 upgrades that may come up.
15 And the reason for that, and I know Sunil 16 mentioned this, is we don't -- we don't feel the open 17 findings impact the risk-informed decision-making 18 process because even if you have an open findings the 19 way that a PRA maintenance program works you still 20 have to evaluate and disposition those findings 21 related to the specific application.
22 So that requires a certain level of effort 23 by the utility to do that. If you don't close a 24 finding that effort, you know, gets carried forward.
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76 However, there's also a cost associated with going 1
through the formal process of closing these findings.
2 So it is appropriate for the utilities to 3
weigh the, you know, the cost and efficiency benefits 4
associated with the closure and take the appropriate 5
path.
6 So I will be very happy to -- that the 7
staff agree to leave -- really, leave that to our 8
discretion with the key point is we still have to 9
evaluate and disposition anything that's open as we 10 move forward.
11 Next slide, please, Andrea.
12 A little bit regarding our report on 13 newly-developed methods. That's PWR Owners Group 14 19027.
15 We developed this, really, detailing the 16 process and requirements for technical adequacy and 17 newly-developed methods through a series of meetings 18 with a broad range of stakeholders.
19 Even though everything is documented in a 20 PWR Owners Group report, we did have representatives 21 from both Owners Groups, both the P and the B, NEI, 22 the Joint Committee on Nuclear Risk Management that 23 owns the PRA standard as well as the NRC. So it 24 really is a broad stakeholder input that went into 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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77 that document.
1 And we also -- also through the process 2
there were three peer review pilots that actually 3
helped inform the final working as far as the 4
requirements and kind of report content in the final 5
document.
6 Next slide, Andrea.
7 So the content from the initial revision 8
that we submitted for inclusion in the 2021 edition of 9
the standard, that's been coming up.
10 We actually, you know, didn't want to 11 maintain our document as the document that has the 12 peer review requirements. You know, as a utility 13 organization we are not generally in the habit of 14 specifying, you know, these types of requirements.
15 So we have been working with JCRN to have 16 this -- these requirements actually transitioned and 17 become part of Part One of the next edition of the PRA 18 standard, which we expect at this point to be 19 published in mid 2021.
20 So with that, prior to submitting Rev 2 21 through the public comment period we did run through 22 another round of comments with the JCNRM so we could 23 harmonize the wording of our requirements to be 24 consistent with the expected wording in the standard, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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78 and you'll see that that effort was done and that 1
really forms the basis of the changes that we provided 2
through the public comment period as far as the final 3
revision related to the technical requirements for 4
duly developed method peer reviews.
5 If you go to the last slide, Andrea.
6 So and this slide -- I won't go over it in 7
detail, but just -- just a short description of the 8
types of changes that we made.
9 Really just wanted to clarify the 10 relationship between the newly developed methods and 11 existing methods as clarified. Really, this is --
12 goes to when you are revising a method rather than 13 something that is a new method on a couple of the 14 supporting requirements and high-level requirements.
15 Based on feedback from JCNRM we did change 16 some of the wording to be consistent with the 17 appropriate action verbs that the standard uses, and 18 similarly we submit -- we changed the structure a 19 little bit on the report format to meet the staff's 20 requirements.
21 It is important to note that, you know, as 22 we go through and we do peer reviews of these newly 23 developed methods there will be a report that's 24 submitted to the NRC that will be, you know, publicly 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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79 available for the entire industry so that everyone is 1
aware of what new peer reviews or not -- what newly 2
developed methods have been peer reviewed.
3 So you don't have to go through and do a 4
-- do a separate peer review with the method as we 5
start to work through this process.
6 And with that, that ends my presentation 7
unless you have any questions.
8 MEMBER DIMITRIJEVIC: Do you have -- do 9
you have some example you can tell us the -- that this 10 new -- this new developed method was developed by the 11 licensee and it was not the -- some industry accepted 12 new method?
13 I don't know. Did I put expression well?.
14 You know I'm just explaining my concern on them.
15 MR. LINTHICUM: Are you asking for 16 examples of what new -- what a newly developed method 17 has been put through the process?
18 MEMBER DIMITRIJEVIC: Yes, but that method 19 is not, for example, that the new HRA method, those by 20 NRC, but it's some method developed by licensee.
21 MR. LINTHICUM: Yeah. So yeah, these --
22 yeah, these are really methods that are developed by 23 not necessarily a licensee. Generally, licensees 24 don't develop new methods.
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80 But, really, they would be potentially 1
methods that would be developed by, you know, either 2
PRA consulting firms, the Electric Power Research 3
Institute, or the Owners Groups with regards to new 4
methods.
5 I mean, you know, a licensee could develop 6
a new method but, you know, generally that's not done.
7 It's through these other, I would call, the technical, 8
you know, knowledge branch, you know -- you know, of 9
the industry rather than, you know, the licensees 10 developing these new methods.
11 It doesn't really apply to NRC. Yeah, it 12 doesn't really apply to NRC methods. If it -- you 13 know, if NRC develops a new method that they find 14 acceptable, I mean, we don't necessarily need to do a 15 peer review of that method because it's a separate 16 process.
17 MEMBER DIMITRIJEVIC: Right. Or if they 18
-- right. Or if that they have already endorsed the 19 method developed by EPRI or something, right? That 20 only applies to --
21 MR. LINTHICUM: That's correct.
22 MEMBER DIMITRIJEVIC: Yeah. Okay.
23 Correct.
24 MR. LINTHICUM: Yeah, and it's -- it is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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81 optional. It's not a requirement. You know, we still 1
retain -- there still retains the option of submitting 2
a new method through a comparable board review.
3 But they tend to -- the -- you know -- you 4
know, takes a lot of time and effort to get something, 5
you know, endorsed through that process.
6 MEMBER DIMITRIJEVIC: Okay. Thank you.
7 (Pause.)
8 MR. GILBERTSON: Okay. I think maybe --
9 am I -- I'm probably back up here to finish off the 10 rest of the NRC's presentation.
11 MEMBER DIMITRIJEVIC: Okay.
12 So the next will be the path forward.
13 MR. GILBERTSON: Correct. Yes.
14 MEMBER DIMITRIJEVIC: Okay.
15 MR. GILBERTSON: So is my presentation 16 showing up?
17 MS. LUI: Yes.
18 MR. GILBERTSON: Okay.
19 MS. LUI: You'll need to go to next slide.
20 Good.
21 MR. GILBERTSON: Okay. So regarding the 22 path forward, for Reg Guide 1.200 Revision 3 we are at 23 the end of our process for publishing the document.
24 We are still in the very final stages of the internal 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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82 reviews and concurrence.
1 We will be considering any ACRS full 2
committee feedback as, you know, through discussions 3
and/or through a letter to the extent that it's 4
supplied there as well.
5 As it stands, we are expecting a final 6
publication sometime late this year to early next year 7
depending on a few -- a few factors that still need to 8
get sorted out. But, in general, it's -- we are 9
expecting it to be published relatively soon.
10 So looking forward beyond Revision 3 of 11 1.200, the staff have already started thinking about 12 Revision 4.
13 I
would point out that our plans 14 associated with Revision 4 are still very much in the 15 nascent stages and there are -- we have some 16 dependencies between our guidance document and the 17 efforts of the ASME/ANS JCNRM who are responsible.
18 They are the standards development 19 organization responsible for publishing the consensus 20 PRA standards. And so for the past couple years or so 21 now, we have generally -- the staff have been 22 expecting that Revision 4 1.200 would include review 23 and endorsement of the next edition of the ASME/ANS 24 Level 1 LERF PRA standard, which, as Roy mentioned, is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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83 due to come out relatively soon as well.
1 The ASME/ANS Level 2 PRA standard as well 2
as the advanced LWR PRA standard, which is more of a 3
-- in some regards, it's a bit of an overlay on top of 4
the requirements in the Level 1 LERF PRA standard and 5
helps to describe what requirements are applicable to 6
different stages of the design life cycle and the 7
licensing process.
8 So the next edition of the Level 1 LERF 9
PRA standard I'll speak about that just for --
10 briefly. You know, this is a document that has been 11 in -- under development for the better part of the 12 last six to seven years or so in the JCNRM.
13 There's been a lot of thinking that's gone 14 into it. It's in the final stages of being -- of 15 achieving consensus and going through its balloting 16 process.
17 But the NRC has to -- we have to wait for 18 that to get finished, at least until the point where 19 we have what is ostensibly a technically stable 20 document that we could say okay, you know, they're 21 just doing editorial changes but we can look at the 22 technical contents and start making our decisions on 23 what our endorsement looks like.
24 The JCNRM's efforts related to the other 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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84 two LWR standards for Level 2 and advanced LWRs are 1
very much tied to the Level 1 LERF PRA standard in 2
that the Level 1 LERF PRA standard is sort of the 3
bedrock for the structure and organization of the 4
other PRA standards.
5 So once the Level 1 LERF PRA standard is 6
finalized and it's published, the other efforts for 7
Level 2 and advanced LWR PRAs those will be starting 8
their finalization process to align with the Level 1 9
10 There's been a lot of work going on, a lot 11 of coordination between all of those different groups.
12 So we will need to wait for those to come forward.
13 And then I would also point out that the -- as some 14 members are already aware, the advanced non-LWR PRA 15 standard is going to be endorsed in a new NRC 16 regulatory guide or some endorsement vehicle with, 17 notionally, it's going to be a Reg Guide but we 18 haven't totally settled on that yet.
19 But I wanted to raise that because there 20 is a recognition by the staff an appreciation for the 21 fact that there are a lot of connections between the 22 advanced non-LWR PRA standard and the LWR standards.
23 In particular, the advanced non-LWR 24 standard requirements were largely sourced and derived 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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85 and even adopted directly from the LWR PRA standards 1
for the related portions of PRA analysis.
2 So there's an additional connection point 3
in terms of achieving alignment, achieving 4
consistency. The advanced non-LWR PRA standard is 5
being moved forward ahead of the LWR standard.
6 So the staff are already in the mode of 7
thinking about what our endorsement will look like 8
that for that advanced non-LWR PRA standard.
9 But, of course, we have to understand what 10 our positions have been in the past because there are 11 related requirements, some of which that are 12 technology neutral already, and we just -- we have to 13 ensure consistency in our staff position in how we --
14 how we interpret those requirements.
15 And I guess, you know, something else, 16 getting back to the comment about the list of hazards 17 that we were discussing earlier, I would point out the 18 next edition of the ASME/ANS Level 1 LERF PRA standard 19 does include a non-mandatory appendix very similar to 20 that of the 2009 PRA standard and it does have an 21 expanded set of hazards to include things like heavy 22 load drop.
23 Off the top of my head, I think one of the 24 other ones, for example, is non-safety-related 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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86 building fires, looking at other -- like, other types 1
of external fires like grass fires and not just, you 2
know, a forest fire, for example.
3 So there is an expansion of that. But I 4
would point out, as I mentioned before, the staff will 5
be looking at that and also will be considering 6
whether there is a need for additional hazards beyond 7
what's listed in the next edition.
8 There are some guidance documents 9
available. I believe EPRI has a guidance document 10 that provides a similar what is intended to be a 11 fairly expansive list of hazards to consider that 12 includes everything, internal hazards all the way out 13 to what we -- are colloquially called these other 14 hazards.
15 So things that are not -- hadn't been 16 traditionally modeled using a PRA but are often 17 screened out. And that's a pretty expansive list 18 that's in that EPRI document.
19 So it's just an example of some of the 20 things that the staff will be thinking about as we 21 look at Revision 4 of Reg Guide 1.200. So it is on 22 our radar to consider those things.
23 MEMBER DIMITRIJEVIC: I have a question.
24 This is Vesna Dmitrijevic again.
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87 MR. GILBERTSON: Yes?
1 MEMBER DIMITRIJEVIC: Usually, I mean, 2
your Reg Guide endorses the PRA standards, you know, 3
related to the high level -- the requirements and the 4
supporting requirements.
5 However, the Reg Guide should also -- I 6
mean, you know, the -- it's there to define the 7
process, right, and that the process feel different --
8 is different when you are dealing with not mature 9
PRAs.
10 Like, it would be case -- you know, 11 because if you go for an advanced light-water PRA 12 standard then you look in the standard itself, which 13 defines what requirements cannot be met in the -- in 14 the, for example, the design certification level when 15 you don't have operating procedures and things like 16 that.
17 But we have a situation here where we are 18 dealing with a not mature PRA which will be maturing 19 through the process of the -- between design 20 certification and fuel load. So does the -- do you 21 think that the reg guide revision four will try to 22 make attempt to define this process?
23 MR. GILBERTSON: So --
24 MEMBER DIMITRIJEVIC: Or is it just going 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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88 to say concentrated on recently formed applications?
1 MR. GILBERTSON: So in principle, yes. I 2
think it should, and as far as the guidance document 3
the staff are already in the process of thinking about 4
for advanced non-LWR PRA standard. We are having to 5
deal with the same -- the same issue.
6 So, for example, what's the process when 7
a PRA goes from -- is being used from the design 8
certification stage and then it's used for a COL 9
application? What are the difference in requirements?
10 Does it need a peer review?
11 Are the staff reviewing it? You know, 12 what are the -- what's the process for that. So that 13
-- I don't know at the moment how that will -- how 14 that will work out for LWRs. But I know that is 15 something that we are thinking about for the -- for 16 the non-LWRs.
17 MEMBER DIMITRIJEVIC: Okay. Well, that --
18 you're right. That's, actually, the essence of my 19 question because this advanced light-water also new 20 designs and they will be meeting some of the similar, 21 you know, issues which are more obvious for non-light-22 water reactors, right?
23 MR. GILBERTSON: Right.
24 MEMBER DIMITRIJEVIC: Now, my other 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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89 concern is that in this new PRA, so all advanced 1
light-water reactor, you know, they said the PRAs 2
which are being developed now in the design 3
certification stage, that there is the 146 guides also 4
which define what are risk-informed -- you know, risk-5 informed applications that traditionally define as the 6
ones to be rated though the Reg Guide 1174 and, you 7
know, subsequent, you know, 1176, 78, whatever. One 8
of them is now 10 CFR 5069.
9 But also there is a risk-informed -- there 10 is a use of PRA in a lot of the design applications 11 which are not these formal risk-informed applications 12 but there is still use of the PRA, for example, to 13 define the RAF program or the important human actions 14 for human factor engineering or in some cases to ask 15 for exemption from general design criteria.
16 So these uses of -- so PRA is used in 17 design certification on numerous places. The question 18 is should those use of the PRA be considered risk--
19 informed applications.
20 MR. GILBERTSON: So I appreciate you 21 raising that question and that is a perfect example of 22 one of these issues that has -- that has relevance 23 across LWRs and the non-LWRs.
24 That is something -- that is exactly 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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90 something that we are considering right now, how do we 1
deal with that for advanced non-LWRs because, like you 2
said, there are plenty of examples of where the PRA is 3
used and what are really considered to be, you know, 4
a risk-informed application, other parts of the 5
application.
6 The staff are still deliberating on that 7
and trying to come to a solution on how that is 8
handled. So I would have to -- I would have to caucus 9
with the staff first before I could provide I guess 10 any more additional feedback on that.
11 MEMBER DIMITRIJEVIC: That's all right.
12 I don't even need the answer. I just wanted to hear 13 that you're thinking about those things.
14 MR. GILBERTSON: Yes, absolutely.
15 MEMBER DIMITRIJEVIC: Okay. Well, thank 16 you. Okay.
17 MR. GILBERTSON: Okay.
18 Okay. So this last slide, you know, I 19 wanted to provide this slide to just give some 20 additional insights into other work, related work, 21 that the staff are considering, and, you know, in the 22 past ACRS full committee letters that have been 23 written related to Reg Guide 1.200, a common theme 24 that rose was that of guidance and the treatment of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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91 uncertainties.
1 And so, you
- know, from those 2
interrogations and those discussions, the staff 3
eventually came to develop NUREG 1855 for the 4
treatment of uncertainties in PRA for risk-informed 5
decision-making.
6 That was originally published, and I 7
believe it's 2009, it was Revision 1 and -- or 8
Revision 0. Revision 1 was published more recently in 9
2017.
10 And so there are some natural aspects of 11 that guidance document, NUREG 1855 Revision 1, that 12 need to be updated because they do have some temporal 13 references to documents, for example, the 2009 PRA 14 standard.
15 So, you know, for example, one of the 16 least things that we'll need to do and consider is 17 just finding those references and updating the 18 document the reflect the next edition of the advanced 19
-- I'm sorry, of the Level 1 LERF PRA standard once 20 that becomes available.
21 For example, we point -- 1855 points to 22 specific supporting requirements in the Level 1 LERF 23 PRA standard that relate to screening, completeness, 24 uncertainty, that sort of thing.
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92 So those will just need to be updated.
1 And beyond that, you know, we'll also take a more 2
holistic review to consider other changes that were 3
made to -- in the Level 1 LERF PRA standard to see 4
where additional guidance might need to be revised or 5
adjusted.
6 Another aspect that the staff are 7
considering is the potential development of 8
application-specific guidance, and so this, you know, 9
would really be focused on providing that additional 10 guidance and insight into how to treat uncertainties 11 for, say, a 5069 application or for just a 505 risk-12 informed completion time program.
13 We have seen some instances where there's 14 potentially a need for that but it is something that 15 we are just considering at this point and we have to, 16 obviously, work with the program offices to understand 17 what their needs are.
18 Another -- it's a bit of a larger point 19 here, expanding the guidance on uncertainty and risk-20 informed decision-making. There's been some work on 21 this in other areas internationally.
22 IAEA provided or published recently a 23 document on integrated risk-informed decision-making.
24 There have been discussions internally and some 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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93 thinking about how 1855 might be expanded to offer 1
some more useable guidance on how to do risk-informed 2
decision-making with uncertainties.
3 But at the same time, you know, balancing 4
that with the level of prescription that's not too 5
constraining. So that's -- that's probably a bigger 6
effort.
7 There is some guidance already in 1855.
8 It's just -- it's relatively general or relatively 9
high level and so there could be an opportunity to 10 improve that.
11 And then, finally, I just wanted to 12 mention that we would also consider uncertainties 13 related to PRA for advanced reactor designs and 14 understanding -- I think earlier on Monday during the 15 future plant design subcommittee meeting there was a 16 discussion and concerns raised about completeness 17 uncertainty.
18 Those concerns were also discussed at the 19 February 2020 subcommittee meeting for this Reg Guide.
20 So we do have that on our minds and we want to think 21 about that, particularly for advanced reactor designs 22 and to include, obviously, advanced non-LWRs as well 23 because of the lack of experience that we have in the 24 technologies, operating experience, and application of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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94 PRA in general for those -- for those new designs.
1 So with that, that is -- that is the end 2
of my presentation. I am happy to entertain any 3
questions or comments.
4 MEMBER DIMITRIJEVIC: I just wanted to add 5
something with your last point, because the -- somehow 6
uncertainty in the advanced application is a sort of 7
afterthought. You know, it's something they have to 8
do and they can follow guidance, do it well or less 9
well.
10 It could be small. It could be big. But 11 that doesn't impact any of the decision-making. There 12 are two plans which are coming with another range of 13 certainty, a large range of certainty, uncertainties 14 done perfectly making an effort to put the -- for 15 example, modeling uncertainty.
16 There is no any, you know, regulatory 17 implication of these things.
It's a
total 18 afterthought. It's just some section being done, sit 19 there, and not being really used.
20 And this could be related to the way how 21 we treat the mean they can use -- they can have this 22 state of knowledge, the phenomena identified, or they 23 can just treat all uncertainties as independent.
24 There is no really -- you know, there is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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95 not anything which when we review this, you know, 1
makes for us a reason to make a comment on it.
2 That can be related to use of the mean 3
values versus point estimates or something. But that 4
nuclear regulation is very much lacking in this area.
5 That's my personal opinion.
6 MR. GILBERTSON: Okay. I appreciate that.
7 Thank you. I'll definitely take that back and -- and 8
for the staff to consider.
9 MEMBER DIMITRIJEVIC: Okay. So should we 10 open now for public comments and -- or there is, do 11 the members have comments at this moment? Or we can 12 also save them for member discussions after that. So 13 shall we maybe open for public comments in this 14 moment?
15 Christiana? Chris, are the -- are our 16 public lines open?
17 PARTICIPANT: The public bridge line is 18 open for comment. We would ask that folks from the 19 public please ensure your device is unmuted.
20 MEMBER DIMITRIJEVIC: Okay. So at this 21 moment if anybody from public would wish to make a 22 comment please do so.
23 MS. LUI: I am on a public line and so I 24
-- we can be sure that the public line is open.
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96 DR. SCHULTZ: Christiana, this is Steve 1
Schultz. Can you hear me?
2 MEMBER DIMITRIJEVIC: Yes, we can hear.
3 We just heard you, yes.
4 Hello?
5 MEMBER BLEY: I don't think you have any 6
comments, Vesna.
7 MEMBER DIMITRIJEVIC: Okay. I know the --
8 okay. So we -- did Steve Schultz would like to make 9
a comment?
10 DR. SCHULTZ: I just wanted to let you 11 know the public line was open.
12 MEMBER DIMITRIJEVIC: Oh, okay. All 13 right. Okay. Sorry, I misunderstood. Okay. So no 14 one has a public comment. So in this moment we can 15 proceed with the members' discussion.
16 Sorry, I accidentally muted myself. Do 17 members wish to make additional comments?
18 (No response.)
19 MEMBER DIMITRIJEVIC: Okay. What is our 20 waiting period?
21 MEMBER BLEY: I think -- I think you've 22 got it.
23 MEMBER DIMITRIJEVIC: Okay.
24 CHAIRMAN SUNSERI: You got it.
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97 MEMBER DIMITRIJEVIC: Okay. So I would 1
like to make this -- the closing, the summary. I 2
would like to thank the staff for coming back and 3
inform us all the changes that were incorporated in 4
order to complete Revision 3 of Reg Guide 1.200, 5
including since our last meeting the resolution to the 6
public comments.
7 We recognize that this revision fulfills 8
an important role to close in timely fashion the gap 9
related to resolution of the acceptability of new 10 methods or models in order to support future risk-11 informed regulatory initiatives.
12 As a part of this resolution, this 13 revision endorses the technical content found in NEI 14 17-07 and PWR OG 19027.
15 This Reg Guide also endorses a third 16 document, the ASME/ANS Case One for seismic PRA and in 17 addition the revision provides the general updates 18 related to organization and numerous enhancements and 19 clarification to guidance.
20 We agreed the Reg Guide meets the intended 21 goals and objectives, and that the -- we sent some 22 comments to the completeness of the hazard list. So 23 we can discuss now the staff has not requested the 24 letter from us and we have also discussed this in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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98 February that if we are going to just write a letter 1
to say to publish this without having major comments 2
maybe we do not have a need for the letter.
3 So, Dennis, you had a comment on the --
4 which was -- supported the causes of completeness of 5
the hazard list. Do you see this as appealing reason 6
for us to write the letter? How do you feel about it?
7 MEMBER BLEY: The more I thought of it --
8 I'd be delighted if the staff added a little 9
clarification in their Appendix D. But I don't think 10 we need to write a letter on this. The issues that 11 kind of fill out this list are covered in lots of 12 other guidance already.
13 But I think in the future that principle 14 of looking at consistency rather than of what's 15 important should be kept in everyone's minds. But I'm 16 happy with your proposals to go ahead.
17 MEMBER DIMITRIJEVIC: So we -- the 18 transcripts of this meeting should serve as our 19 expression of the committee support of the -- this 20 completed part of its assurance.
21 So or maybe the staff would like that we 22 issue -- that our executive director issues memo 23 stating that we agree with issuing the Reg Guide. We 24 can discuss this now. I mean, how does staff feel 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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99 like, you know, about --
1 MEMBER BLEY: Well, it's not a staff 2
question so much, Vesna. We have been involved in all 3
of these risk applications since their very beginnings 4
as a committee and I just think we ought to have 5
something beyond the transcript and maybe executive 6
director memo saying we have no objection with 7
releasing this Reg Guide. I think we ought to have 8
something.
9 MEMBER DIMITRIJEVIC: Okay. Is Scott on 10 the line?
11 MR. MOORE: I am on the line.
12 MEMBER DIMITRIJEVIC: So the -- would we 13 issue -- if you issue a memo stating that we agree 14 with issuing these Reg Guide is that one option for 15 us, too?
16 MR. MOORE: I can always issue a memo at 17 the committee's direction. I think the committee 18 should direct me what you want me to issue.
19 MEMBER DIMITRIJEVIC: Okay. Okay. So --
20 MEMBER MARCH-LEUBA: Yeah, this is -- this 21 is Jose. I don't see how the procedure will work. I 22 mean, you're asking Scott to write our letter. We 23 don't have to write a 25-page letter. We can write a 24 two-line letter that says we agree with publication of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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100 the guide. It doesn't need to be long. But I don't 1
-- I don't see how we can delegate our letter to 2
Scott.
3 MEMBER DIMITRIJEVIC: Well, this is one of 4
-- this is one of the options the committee has.
5 Also, I have to point out that in February meeting 6
you're the one who brought up this letter, why do we 7
need to write the letter. We just state the issue Reg 8
Guide and just went to transcripts yesterday.
9 So that was a part of discussion in 10 February and I thought actually that makes sense, the 11 issuing the committee letter just stating the Reg 12 Guide should be issued.
13 MEMBER BLEY: Vesna, this is Dennis. I'm 14 just one member. I kind of thought we ought to be on 15 record somehow. I wouldn't push it.
16 I mean, I think letting it stand on the 17 transcript is probably fine. It's -- my preference 18 would be to have a very short letter saying we think 19 it's time to issue this Reg Guide. But that's just 20 me. I'm only one.
21 MEMBER DIMITRIJEVIC: Okay. So how do the 22 rest of the members feel about this? Do you think we 23 should issue a formal letter or the -- this discussion 24 should be fine? Does anybody have a --
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101 MEMBER MARCH-LEUBA: I think -- this is 1
Jose -- procedurally, we only have two options.
2 Either we issue a letter, a very short letter.
3 Doesn't have to be more than a page. Or we remain 4
silent, because the ACRS can only speak through its 5
members.
6 We cannot just ask Scott to write our 7
letter. So I don't carry any weight, honestly. But, 8
procedurally, those are the only two options. Remain 9
silent or speak. I mean --
10 MEMBER DIMITRIJEVIC: Well, Jose, as a new 11 member I was informed -- I was informed that we could 12 also -- that our executive director could issue memo, 13 which is not a formal letter. So that was something 14 I was informed about. So --
15 CHAIRMAN SUNSERI: Well, let's -- let's 16 not distract ourselves. The question on the table 17 right now is whether or not the committee wants to 18 write a letter on this.
19 MEMBER DIMITRIJEVIC: Okay.
20 CHAIRMAN SUNSERI: You heard two members 21 say they could go either way. We have you as the 22 chairman of the group recommending no letter. So 23 let's hear from the other members.
24 This is our opportunity. This is as we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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102 discussed in our retreat our decision-making point for 1
whether or not we want a letter. We heard the 2
subcommittee on this. We have not heard a full 3
committee briefing on it. So members need to speak up 4
and provide some good input on this.
5 MEMBER BALLINGER: This is Ron. I think 6
for posterity purposes we need to somehow enshrine 7
this in a document which the general public that goes 8
to the website can see.
9 So I guess I'm in favor of a -- what 10 people say is a two-line letter and, hopefully, we 11 would not be debating the two-line letter for five 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> once we get to look at it.
13 MEMBER KIRCHNER: Vesna, this is Walt.
14 Since we, as a committee, have put this much effort 15 into this as well as the effort of the staff and 16 industry, my -- I lean with Ron that even if it's a 17 short letter -- two lines is silly -- but just a short 18 letter and maybe that's also a vehicle then to raise 19 Dennis's comments if we all concur and then it's in 20 the record. I think it a good idea.
21 MEMBER DIMITRIJEVIC: Okay. Anybody else 22 have an opinion on the subject?
23 MEMBER RICCARDELLA: This is Pete. I 24 don't have a strong feeling one way or the other.
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103 I'll go along with whatever the majority decides.
1 MEMBER DIMITRIJEVIC: Should we vote on 2
this or should we --
3 CHAIRMAN SUNSERI: Well, yeah. I'm taking 4
notes here so I'm just going to go down the list. So 5
Charlie, what's -- what's your position?
6 (No response.)
7 CHAIRMAN SUNSERI: Member Brown? Unmute.
8 MEMBER BLEY: While you're waiting for 9
Charlie, this is Dennis. Show me as favoring a 10 letter.
11 CHAIRMAN SUNSERI: Okay. All right. So 12 I'll undo your either way with a letter. All right.
13 So we know Vesna. Jose, I had you as either way. Or 14 you want to modify that?
15 MEMBER MARCH-LEUBA: Abstention. An 16 abstention.
17 CHAIRMAN SUNSERI: Okay. Dave, thoughts?
18 MEMBER PETTI: I'm indifferent. I'll go 19 with whatever the majority.
20 CHAIRMAN SUNSERI: Okay. The majority is 21 going to be two people. All right. Joy, your 22 thoughts?
23 VICE CHAIRMAN REMPE: I think a very short 24 letter would be wise because ACRS has a long history 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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104 of being very involved and proactive about PRA, and I 1
think it would be helpful to have a short letter.
2 CHAIRMAN SUNSERI: And, Pete, I had you 3
either way. So you want to recant or stick with that?
4 MEMBER RICCARDELLA: No. Like Jose, I'll 5
abstain.
6 CHAIRMAN SUNSERI: All right.
7 MEMBER BROWN: Matt, did you ask for me?
8 CHAIRMAN SUNSERI: I can loop back to you 9
now. So we're discussing whether or not we want to 10 have a short letter on this topic. What's your 11 opinion?
12 MEMBER BROWN: I'm not as knowledgeable.
13 However, I would not abstain. I think it's important.
14 This is another -- a big revision to it.
15 We're always talking about it, and it 16 seems that we ought to at least stick our finger in 17 the water. A short letter, to me, is appropriate.
18 CHAIRMAN SUNSERI: Okay.
19 MEMBER BROWN: As long as -- if we have 20 got a major issue we ought to bring it up. This 21 doesn't sound like, based on listening to the 22 presentations, that there's a major issue here.
23 But I know I've written at least one or 24 two letters where there was no comments in our letter 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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105 other than we agreed with it. So I think that's a 1
good idea.
2 CHAIRMAN SUNSERI: All right. So by my 3
tally it looks like we have half or more of the 4
members would favor a short letter. So, Vesna, I 5
think we should be preparing a short letter.
6 MR. BOWMAN: And can I -- this is Greg 7
Bowman with the staff. If I could just offer -- I 8
think I really appreciate the letter. I think it will 9
actually -- I know -- I know this is unsolicited 10 feedback.
11 But I think that will actually help us 12 having documented ACRS support of this major project.
13 So I appreciate the outcome that you're coming to.
14 Thank you.
15 MEMBER BLEY: Vesna, this is Dennis. You 16
-- since I pushed this I would volunteer to get you by 17 later today a draft, if you would appreciate it.
18 Otherwise, I'll certainly defer to you.
19 MEMBER DIMITRIJEVIC: Okay. All right.
20 Well, thanks, Dennis. That's okay. Then we will 21 probably write this later and we may not have it 22 today. But, you know, we will definitely have it for 23 tomorrow.
24 CHAIRMAN SUNSERI: Yeah. Well, I think 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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106 we'll have a lot of time tomorrow to work on this. So 1
all right.
2 MEMBER DIMITRIJEVIC: Thank you. All 3
right.
4 I would like to add something else, which 5
is much more important for me. This is why I asked 6
for a discussion on the future of things for the 7
Revision 4, because while we have this existing review 8
process, I mean, that serves routine updates quite 9
well.
10 The -- I think for Revision 4 it will be 11 good to establish a process which ensures the 12 committee recommendation and consider sooner rather 13 than later. In other words an immature product 14 shouldn't have been the first we see, you know, 15 because then it's a much -- you know, it's maybe too 16 late to make the major comments.
17 So something like that. Then it will be 18 the -- so our engagement -- it will be good to have 19 first engagement, of course, before the mature product 20 is developed.
21 Since we have an extensive experience with 22 advanced light-water reactor design certification 23 application we are likely to have a more significant 24 recommendation and opinion on the next revision of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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107 this Reg Guide.
1 So this is why I was thinking about that 2
-- that before the staff puts pen to the paper it 3
would be very productive if we have an initial meeting 4
to discuss this whole issue and conceptual approaches 5
for the -- especially for how to incorporate advanced 6
light-water reactor, the standard.
7 The -- it will be -- this will be also 8
important because we just discusses this integrated 9
approach that Revision 4 of Reg Guide 1.200 should be 10 related to non-light-water standard and also for 11 ongoing Part 53 rulemaking, which the committee is 12 actively involved with both.
13 So I would like to propose that we want 14 the staff, through Christiana, to find the best timing 15 and the best foreman so that we can provide timely and 16 relevant recommendations for the Rev 4, and as much as 17 I discussed this with my more experienced colleagues, 18 they say that we can accomplish this through the --
19 having the participatory discussion meetings, which 20 could be either transcribed or not, and in such a 21 meeting we can discuss about this -- we can talk about 22 key issues and the staff can hear the opinion of the 23 individual members.
24 So I just wanted to get this on the record 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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108 that I hope that for the next rev we will find the 1
good format and a good way to get include -- involved 2
in the process earlier.
3 MR. WEERAKKODY: May I ask a clarifying 4
question? This is Sunil Weerakkody, NRR.
5 Dr. Dimitrijevic, I believe when you made 6
that statement it's also including advanced light-7 water reactors and advanced non-light-water reactors?
8 I'm asking --
9 MEMBER DIMITRIJEVIC: No, we -- okay, we 10 are discussing this with you just related to advanced 11 light-water reactor but we are also -- it's the 12 committee working with, you know, the future non-13 light-water reactor and also Part 53.
14 So review and developing Rev. 4 of the 15 Reg Guide. As you show us in your slides, it will 16 include advanced light-water reactor standards. And 17 so right now specifically I was talking about advanced 18 light-water standard, yes.
19 MR. WEERAKKODY: Thank you.
20 CHAIRMAN SUNSERI: All right, Vesna.
21 Thank you.
22 Anything else on this topic?
23 MEMBER MARCH-LEUBA: Yes. Yes. I don't 24 want to be confrontational, Vesna. I'm just talking 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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109 procedure. I mean, you know I'm on procedure now.
1 But if you get involved in the design of the solution, 2
then it challenges independence of our review.
3 It's not the function of ACRS to guide how 4
the staff gets the solution. A function of ACRS is 5
to evaluate whether the solution is acceptable. So 6
that's something to consider.
7 I know you're wanting to get into Chapter 8
15 analysis and everything involved earlier but they 9
won't let me because you're not supposed to. I just 10 wanted to put that concept out there. Independence.
11 MEMBER DIMITRIJEVIC: Well, this will not 12 be the guiding the staff, in my opinion. It is to 13 staff to, you know, here our individual members' 14 opinion on the -- on the -- how does this process 15 impacted our experience with this.
16 I mean, I think that having -- actually, 17 which I think clearly did, having this discussion 18 meetings before we face the final product, you know, 19 a lot of cases can be helpful.
20 MEMBER BLEY: This is Dennis. You know, 21 Jose brings up a very good point and National Academy 22 committees have the same issue arise. It's a fine 23 line between being involved in development and 24 providing early hints of where problem areas might 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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110 live, and we have to live on that second side.
1 We can't be designing programs for the 2
staff. But we can be letting them know where ideas 3
they're considering might run into problems and, you 4
know, Vesna and I talked a little bit about this 5
before and that's what I was getting at by discussion 6
meetings.
7 We have done that on a number of cases in 8
the past as a committee and I've been on both sides of 9
that, and the committee has to be careful not to be 10 part of the development.
11 But we're looking and providing warnings 12 about places it could get into trouble and it lets the 13 staff probe us for ideas of where the snakes might be 14 lying in a new process.
15 MEMBER DIMITRIJEVIC: Thank you, Dennis.
16 CHAIRMAN SUNSERI: Okay. Do you need any 17 other -- any other discussion?
18 So, Vesna, does that wrap up this topic?
19 MEMBER DIMITRIJEVIC: I think that we can 20 wrap this section with this. Thank you, everybody, 21 very much. We are 45 minutes late.
22 But we have a -- we have -- we are 45 23 minutes late and we have to write the letter, so add 24 to our meeting. But I think it will -- likely will be 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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111 short then.
1 CHAIRMAN SUNSERI:
Okay.
So my 2
understanding is the action going forward is is that 3
Dennis has taken on the action to go prepare the draft 4
letter report and we will take that up tomorrow after 5
the T&P session during our report preparation period.
6 And if -- Dennis, if you get that draft 7
out tonight, maybe we could get it distributed so the 8
members could review it in advance.
9 MEMBER BLEY: Yeah, I'm going to -- I'll 10 get something to Vesna first and I'll probably not 11 participate much for a couple hours here to try to --
12 MEMBER DIMITRIJEVIC: Well, the thing is 13 I already have a draft prepared and --
14 MEMBER BLEY: Oh, you do? Okay.
15 MEMBER DIMITRIJEVIC: Yes, and it's a very 16 rough draft. But I will send it to you so please 17 participate in this. This shouldn't take a long time.
18 So --
19 MEMBER BLEY: Well, one of the objections 20 that was brought up earlier, I was chairman and after 21 that I've kept a -- I think it was a Chairman Stratton 22 letter on the board as an example of concise ACRS 23 letters. It was a very short paragraph.
24 MEMBER DIMITRIJEVIC: Okay. I didn't --
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112 CHAIRMAN SUNSERI: Well, let me -- let me 1
-- you can work offline on that.
2 MEMBER DIMITRIJEVIC: Yes. We will work 3
offline. Let's finish, go for lunch. And when 4
should we come back then?
5 CHAIRMAN SUNSERI: So what I -- let's talk 6
about the rest of the day then. We normally take 7
lunch around 1:00 o'clock and it's just too early, I 8
think, for the people. Half of the committee is on 9
Mountain or East Coast time -- West Coast.
10 So I'd like to hold out until 1:00 o'clock 11 for lunch. So I'm going to propose we take a 10-12 minute break, reconvene at 12:30.
13 (Whereupon, the above-entitled matter 14 concluded at 12:19 p.m.)
15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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Regulatory Guide 1.200, Revision 3 Briefing for the Advisory Committee on Reactor Safeguards Full Committee Anders Gilbertson Technical Lead / Reliability and Risk Analyst RES/DRA/PRB Anders.Gilbertson@nrc.gov November 5, 2020 Shilp Vasavada Senior Reliability and Risk Analyst NRR/DRA/APLC Shilp.Vasavada@nrc.gov Sunil Weerakkody Senior Level Advisor NRR/DRA Sunil.Weerakkody@nrc.gov
Overview
- Purpose
- Background
- Changes incorporated into Revision 3
- ACRS Subcommittee members feedback
- Primary regulatory driver for Revision 3
- Resolution of public comments on DG-1362
- Path forward 2
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Purpose To brief the ACRS Full Committee and solicit feedback on the staffs resolution of public comments on the staffs proposed revision 3 to Regulatory Guide (RG) 1.200 (i.e., DG-1362*)
- Available in the Agencywide Document Access and Management System (ADAMS) under accession No. ML19308B636 3
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
=
Background===
- RG 1.200 provides an approach for determining the technical acceptability of a base probabilistic risk assessment (PRA) model for use in regulatory decisionmaking for light-water reactors (LWRs)
- PRA acceptability is determined with respect to the following aspects of the base PRA:
- Scope
- Level of detail
- Conformance to consensus PRA standard technical elements (i.e., technical robustness)
- Plant representation 4
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Background - PRA Acceptability 5
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Each element depends on the other in order to demonstrate PRA acceptability This paradigm obviates the need for an in-depth staff review of the base PRA model
Background - PRA Acceptability (cont) 6 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Risk-Informed Inservice Inspection 50.69 SSC Categorization TSTF-425, Surveillance Frequency Control Prgm.
NFPA-805, Risk-Informed Fire Protection RITS-4b, Risk-Informed Completion Times Required scope, level of detail, technical robustness, and plant representation
- Greater reliance on PRA
- More flexibility for licensee
- More complex staff review
Changes incorporated into RG 1.200, Revision 3
- Endorses new industry documents:
- NEI 17-07, Revision 2 (ML19241A615)
- Consolidates predecessor industry PRA peer review guidance for different hazard groups
- PWROG-19027-NP, Revision 2 (ML20213C660)
- Includes requirements for determining acceptability of newly developed methods (NDMs) and necessary submittal documentation
- ASME/ANS RA-S Case 1 (i.e., the seismic code case) 7 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Changes incorporated into RG 1.200, Revision 3 (cont)
- Provides a new glossary of terms
- Some terms adopted directly from PWROG-19027-NP
- Provides descriptions of hazards to be considered in the development of a PRA RG 1.200, Revision 3, retains the staff endorsement of ASME/ANS RA-Sa-2009 with an exception for terms and definitions endorsed from PWROG-19027-NP, Revision 2 8
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
ACRS Subcommittee Members Feedback
- The staff did not identify changes based on views expressed by committee members 9
RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Primary Regulatory Driver for RG 1.200, Revision 3
- Evolution of the peer review process
- Gap in Rev. 2 of RG 1.200 with respect to peer review of NDMs
- Significance of closing this gap, specifically for (Risk-Informed Technical Specification (RITS)-4b)
- Strategy to close this gap using PWROG-19027-NP and NEI 17-07 10 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
A Gap in RG 1.200 and the ASME/ANS Level 1/LERF PRA Standard
- For each technical element, the ASME/ANS Level 1/LERF PRA standard provides high-level requirements (HLRs) and supporting requirements (SRs).
- 2009 version of the ASME/ANS Level 1/LERF PRA standard endorsed via Revision 2 to RG 1.200 does not provide HLRs or SRs for NDMs; Furthermore, there is no definition of what constitutes an NDM.
- This gap resulted in inefficiencies in the staffs review of NFPA 805 applications and loss of confidence of the peer review method to adequately peer review NDMs.
11 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Importance of Closing the Gap; Base PRA Acceptability for an Application 12 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Risk-Informed Inservice Inspection 50.69 SSC Categorization TSTF-425, Surveillance Frequency Control Prgm.
NFPA-805, Risk-Informed Fire Protection RITS-4b, Risk-Informed Completion Times Required scope, level of detail, technical robustness, and plant representation
- Greater reliance on PRA
- More flexibility for licensee
- More complex staff review
Current Solution to the Gap
- For RITS-4b applications, staff has imposed the following Administrative Technical Specification (TS)/License Condition:
...and any change in the PRA methods to assess risk that are outside these approval boundaries require prior NRC approval.
13 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Leveraging the Commission Endorsed Peer Review Process to Close Gap SECY-99-256: Rulemaking Plan for Risk-Informing Special Treatment Requirements, October 29, 1999 COMNJD-03-0002, Stabilizing the PRA Quality Expectations and Requirements, September 8, 2003 SECY-04-0118, Plan for the Implementation of the Commissions Phased Approach to Probabilistic Risk Assessment Quality, July 13, 2004 SRM-SECY-04-0118, Plan for the Implementation of the Commissions Phased Approach to Probabilistic Risk Assessment Quality, October 6, 2004.
Establishment of the peer review process using RG 1.200 and consensus standards Peer review process acknowledged in regulations (10 CFR 50.69, November 2004) 14 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Approach to Close the Gap in RG 1.200, Revision 3
- PWROG-19027-NP, Revision 2:
- Provides definitions related to NDMs, PRA maintenance, and PRA upgrade.
- Provides 6 HLRs and 21 SRs for peer review of NDMs (Are being considered for inclusion in the next edition of the ASME/ANS Level 1/LERF PRA Standard)
- NEI 17-07, Revision 2:
- Delineates the process that peer reviewers must use to peer review NDMs in addition to other technical elements of the PRA.
- Emphasis has been added to close as opposed to disposition peer review finding relating to NDMs prior to using them in PRA models.
15 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Public Comments on DG-1362: Summary
- DG-1362 issued for public comment on 07/01/2020 day comment period ending 07/31/2020
- Received 19 public comments
- Nuclear Energy Institute (NEI; 15 comments including text in transmittal letter)
- Pressurized Water Reactor Owners Group (PWROG; 3 comments)
- Individual (1 comment)
- Public comments included responses to two questions in Federal Register notice (FRN) on the closure of peer review findings using an NRC-endorsed approach
- PWROG submitted updated report PWROG-19027-NP, Revision 2, with its public comments 16 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Changes to DG-1362 Based on Public Comments 17 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Peer review of PRAs that credit planned modifications Added guidance for PRAs of operating plants that credit planned modifications
- Considered as a special circumstance
- Staff will address on case-by-case basis
- Peer review and submittal documentation should clearly identify and describe such modifications and design changes
Changes to DG-1362 Based on Public Comments 18 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Correcting the definition of PRA acceptability Added context to the definition of PRA acceptability
- Determined for each risk-informed application
- Considers staff positions in RG 1.200, in application-specific regulatory guidance, and any related requirements
Changes to DG-1362 Based on Public Comments 19 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Clarification of peer review of PRA upgrade(s)
Added guidance for peer review of PRA upgrade(s)
- Performed prior to using the upgraded PRA model in support of a PRA application
- Either for an approved risk-informed program or in the submittal of a risk-informed PRA application for NRC review
- Use of a newly developed method (NDM) in a PRA is considered a PRA upgrade
Changes to DG-1362 Based on Public Comments 20 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Clarifying when differences between the 2005 and 2009 version of the Level 1/LERF PRA standard should be identified in support of a license amendment request Clarified that differences between the 2005 and 2009 version of the Level 1/LERF PRA Standard need to be addressed only if 2005 version used to demonstrate base PRA acceptability
Changes to DG-1362 Based on Public Comments 21 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Ensuring consistency of Appendix D to RG 1.200, Revision 3, Other Hazards, with Part 6 of the 2009 version of Level 1/LERF PRA Standard (ASME/ANS RA-Sa-2009)
Revised Appendix D, Other Hazards to be consistent with Part 6 of the 2009 version of Level 1/LERF PRA Standard (ASME/ANS RA-Sa-2009)
Changes to DG-1362 Based on Public Comments 22 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Removal of a clarification to NEI 17-07, Revision 2, on the documentation of the resolution of peer review findings Public comment identified guidance in NEI 17-07, Revision 2, that addressed a clarification in the public release version of DG-1362 Submission of PWROG-19027-NP, Revision 2 Removal of clarification regarding PRA upgrade determination process because PWROG-19027-NP, Revision 2, addressed the clarification
Changes to DG-1362 Based on Public Comments 23 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Closure of peer review findings (answers to FRN questions)
Agreed that the F&O closure decisions should be based on cost and benefit for licensee F&O closure helps ensure PRA acceptability and reduces resources for licensee as well as staff Added guidance for disposition of peer review findings from any peer reviews
- Findings should be evaluated for their impact on risk-informed application
- Addressed with documented justification and necessary changes to the PRA
- Prior to use of PRA in risk-informed application
Public Comments Resulting in No Changes to DG-1362 24 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Availability of RG 1.200, Revision 2 for use after issuance of Revision 3
- Comment was addressed via publicly available NRC staff response; It explicitly states that Revision 2 is not being withdrawn and, therefore, there is no need to modify DG.
- This practice is consistent with other RG revisions
- Staff, however, anticipates one revision of RG 1.200 to be followed for a given PRA application
- Deviations from the referenced revision of RG 1.200 used in an application submitted to the NRC, including alternatives from other revisions of RG 1.200, should be identified and justified
Public Comments Resulting in No Changes to DG-1362 25 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20 Synopsis of Comment Synopsis of Change to DG-1362 Change use of the term application to narrower term "licensing application" throughout DG-1362 The term application is used in RG 1.200 consistent with the definition of the term PRA application from ASME/ANS RA-Sa-2009, as endorsed by the NRC Application-specific staff positions on PRA acceptability exists in corresponding guidance (e.g.,
Path Forward 26
- Staff considers ACRS Full Committee feedback
- Final reviews and concurrence
- Final publication late-2020/early-2021 RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Path Forward (cont) 27
- Next edition of the ASME/ANS Level 1/LERF PRA standard; and
- ASME/ANS Level 2 PRA standard
- Advanced non-LWR PRA standard to be endorsed in a new RG RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
Path Forward (cont) 28
- Considerations for update of guidance on the treatment of uncertainty in PRA:
- Update to reflect references to the next edition of the ASME/ANS Level 1/LERF LWR PRA standard
- Consideration of application-specific guidance
- Expansion of guidance on uncertainty in risk-informed decisionmaking
- Uncertainty issues related to PRA for advanced reactor designs RG 1.200, Revision 3 Briefing for the ACRS Full Committee 11/5/20
©2020 Nuclear Energy Institute NEI Perspective on RG 1.200, Rev. 3 November 5, 2020 Victoria Anderson, Technical Advisor
©2020 Nuclear Energy Institute 2 Peer review process has been a vital component of implementation of ASME/ANS PRA standard
- RG 1.200 is integral to supporting peer reviews NEI undertook effort to improve process and documentation after over a decade of experience
- NEI 17-07: Performance of Peer Reviews Using the ASME/ANS PRA Standard Rev. 3 includes important updates to support regulatory stability
- Finding closure
- Newley developed methods Role of RG 1.200, Rev. 3
©2020 Nuclear Energy Institute 3 RG 1.200, Rev. 3 notice for comment included additional question to stakeholders Should licensees be required to periodically close all of their PRA peer review findings to ensure confidence in the information used in risk-informed programs?
NEI does not support such an addition to RG 1.200 Configuration control criteria in NEI 17-07 are sufficient to ensure fidelity of information used in risk-informed applications.
Included as part of the PRA peer review
NRC has access to this documentation in LAR reviews No known regulatory concerns that would be addressed by such a requirement Support NRC staff decision to not include such language in RG 1.200, Rev. 3 Federal Register Notice Question to Stakeholders
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3 Global Expertise
- One Voice Roy Linthicum Newly Developed Method Requirements November 2020 ACRS meeting
- This record was final approved on 10/29/2020 9:43:34 PM. (This statement was added by the PRIME system upon its validation)
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3 RG 1.200 Rev 3
- Clarifies long standing issues related to advancing new methods
- Provides cost effective process for regulatory acceptance of new PRA methods
- Retains closure of Peer Review findings as a Licensee decision
- Open findings dont impact risk informed decisions as they need to be considered/dispositioned
- This record was final approved on 10/29/2020 9:43:34 PM. (This statement was added by the PRIME system upon its validation)
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3 PWROG-19027
- Develop process/requirements that allows the technical adequacy of a newly developed method to be accepted through the PRA Peer Review Process.
- Definitions, requirements and peer review process developed during multiple dedicated workshops (PWROG, BWROG, NEI, JCNRM, NRC)
- Three peer review pilots informed the final draft wording (requirements, report content, etc.)
- This record was final approved on 10/29/2020 9:43:34 PM. (This statement was added by the PRIME system upon its validation)
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3 PWROG-19027 Revision 2
- Content from PWROG Revision 0 submitted to JCNRM for inclusion in the upcoming 2021 Edition of the PRA Standard (to be added in Part 1)
- Expected publications in mid 2021
- Few comments received for further harmonization of the NM requirements in the overall structure of the PRA Standard
- Effort to maintain Newly Developed Methods requirements consistent with the evolution of the PRA Standard, this will minimize the effort in R.G. 1.200 Revision 4
- PWROG-19027 Revision 2 incorporates final refinements in NM SRs from interaction with JCNRM
- This record was final approved on 10/29/2020 9:43:34 PM. (This statement was added by the PRIME system upon its validation)
© 2020 Westinghouse Electric Company LLC. All Rights Reserved.
Westinghouse Non-Proprietary Class 3 PWROG-19027 Revision 2 The relationship between NDM and existing methods is clarified, based on early feedback from the NRC that the use of an existing method in a different context was essentially redundant with the finalized definitions.
The wording of the NM HLR and SRs have been enhanced (e.g., use of consistent action verbs, consistent and enhanced wording) following feedback from the ANS/ASME JCNRM during the review ballot for the upcoming Part 1 of the Standard. There is no change in the intent and scope.
The structure of the NDM peer review report portion to be submitted for information to the NRC was updated to reflect the inclusion of SR assessment and F&O (or F&O closure rationale) wording. This is based on the continuous feedback received from the NRC on the pilot NDM reviews performed in 2019/2020 and observed by the NRC staff.
- This record was final approved on 10/29/2020 9:43:34 PM. (This statement was added by the PRIME system upon its validation)