ML20344A391
| ML20344A391 | |
| Person / Time | |
|---|---|
| Issue date: | 10/21/2020 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| Antonescu, C, ACRS | |
| References | |
| NRC-1172 | |
| Download: ML20344A391 (104) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Instrumentation and Controls Subcommittee Docket Number:
(n/a)
Location:
teleconference Date:
Wednesday, October 21, 2020 Work Order No.:
NRC-1172 Pages 1-83 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com 1
1 2
3 DISCLAIMER 4
5 6
UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8
9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.
15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
19 20 21 22 23
1 UNITED STATES OF AMERICA 1
NUCLEAR REGULATORY COMMISSION 2
+ + + + +
3 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
(ACRS) 5
+ + + + +
6 DIGITAL I&C SUBCOMMITTEE 7
+ + + + +
8 WEDNESDAY 9
OCTOBER 21, 2020 10
+ + + + +
11 The Subcommittee met via Video 12 Teleconference, at 9:30 a.m. EDT, Charles Brown, 13 Chairman, presiding.
14 COMMITTEE MEMBERS:
15 CHARLES H. BROWN, JR., Chairman 16 WALTER L. KIRCHNER, Member-at-large 17 RONALD G. BALLINGER, Member 18 DENNIS BLEY, Member 19 VESNA B. DIMITRIJEVIC, Member 20 JOSE MARCH-LEUBA, Member 21 DAVID A. PETTI, Member 22 JOY L. REMPE, Member 23 MATTHEW W. SUNSERI, Member 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
2 ACRS CONSULTANT:
1 MYRON HECHT 2
3 DESIGNATED FEDERAL OFFICIAL:
6 ALSO PRESENT:
7 JOSEPH ASHCRAFT, NRR 8
JOHN SEGALA, NRR 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.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
3 T-A-B-L-E O-F C-O-N-T-E-N-T-S 1
Opening Remarks by Chairman 2
by Charles Brown 4
3 Opening Remarks by Staff 4
by John Segala 7
5 NRC Refresher Review of How the New DRG is Organized 6
Around the Fundamental Principles and How the Review 7
Process Will Ensure That Each Principle is Met in the 8
Design 9
by Jordan Hoellman and Joseph Ashcraft
.. 10 10 Discussion of Staff Changes Made as a Result of the 11 June SC Meeting 12 Questions and Comments
.......... 61 13 Public Comments................. 80 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.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
4 P R O C E E D I N G S 1
(9:31 a.m.)
2 CHAIR BROWN: Good morning. The meeting 3
will now come to order. This is a meeting of the 4
Digital I&C Subcommittee. I am Charles Brown, 5
Chairman of this subcommittee meeting. ACRS members 6
in attendance are Dennis Bley, Matt Sunseri, Jose 7
March-Lueba, Vesna Dimitrijevic, Joy Rempe, Ron 8
Ballinger, Dave Petti, and we have our consultant, 9
Myron Hecht is also attending.
10 Christina Antonescu of the ACRS staff is 11 the designated federal official for this meeting.
12 Christina, I presume the court recorder is set up?
13 MS. ANTONESCU: Yes, John.
14 CHAIR BROWN: Thank you.
15 MS. ANTONESCU: Brandon is joining us.
16 CHAIR BROWN: Thank you. The purpose of 17 this meeting is a bit of a refresher review and how 18 the new revised Draft Design Review Guide:
19 Instrumentation and Controls for Non-Light Water 20 Reactors is organized, around fundamental principles 21 and how the review process will ensure that each 22 principle is met in the design.
23 Also the purpose of the meeting is to 24 discuss what staff changes were made as a result of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
5 the June 2nd Digital I&C Subcommittee meeting, and 1
other changes, how public comments were addressed, how 2
the incorporated comments modified what was presented 3
in June, and how the resolutions impacted how the 4
fundamental principles are applied by reviewers.
5 Today, we have members of the NRC staff to 6
brief the subcommittee. The ACRS was established by 7
statute and was governed by the Federal Advisory 8
Committee Act, FACA. That means that the committee 9
can only speak to its published letter reports.
10 We hold meetings to gather information to 11 support our deliberations. Interested parties who 12 wish to provide comments can contact our office 13 requesting time.
14 That said, we set aside ten minutes for 15 comments from members of the public attending, or 16 listening to our meetings. Written comments are also 17 welcome.
18 The meeting agenda for today's meeting was 19 published on the NRC's public meeting notice website, 20 as well as the ACRS meeting website. On the agenda 21 for this meeting, and on the ACRS meeting website are 22 instructions as to how the public may participate, 23 where requests for making a statement to the 24 subcommittee has been received from the public.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
6 Due to COVID-19, we are conducting today's 1
meeting virtually. A transcript of the meeting is 2
being kept and will be made available on our website.
3 Therefore, we request that participants in this 4
meeting first identify themselves and speak with 5
sufficient clarity and volume so that they can be 6
readily heard.
7 All presenters, please pause from time to 8
time to allow members to ask questions. Please also 9
indicate the slide number you are on when moving to 10 the next slide.
11 We have a bridge line established for the 12 public to listen to the meeting. The public line will 13 be kept in a listen only mode until the time for 14 public comment. To avoid interference, I request all 15 attendees make sure they are muted while not speaking.
16 Based on our experience with previous 17 virtual meetings. I just lost my place. I would like 18 to remind the speakers and presenters to speak slowly.
19 We will take a short break after each presentation to 20 allow time for screen sharing, as well as at the 21 Chairman's discretion during longer presentations.
22 Lastly, please do not use any virtual 23 meeting feature to conduct sidebar technical 24 discussions. Rather, contact the DFO if you have any 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
7 technical questions so we can bring those to the 1
floor.
2 We have scheduled an ACRS full committee 3
meeting in December based on this outcome of this 4
Digital I&C Subcommittee meeting. We will now proceed 5
with the meeting, and I will ask Mr. Jordan Hoellman 6
to share his screen with us while Mr. John Segala, the 7
Branch Chief of the Advanced Reactor Policy Branch, in 8
the Division of Advanced Reactors and Nonpower 9
Production Utilization Facilities, in the Office of 10 Nuclear Reactor Regulation, for any introductory 11 remarks to make before we begin today's presentations.
12 John, do you have any comments?
13 MR. SEGALA: All right. Thank you very 14 much and good morning. The purpose of today's 15 briefing, as you said, is to provide the members an 16 informational overview of the Design Review Guide for 17 Instrumentation and Controls for Non-Light Water 18 Reactor Reviews.
19 The presentation will provide a history of 20 the development of the guidance, and describes changes 21 made to address ACRS observations and public comments.
22 I wanted to take this opportunity at the 23 beginning of the meeting to place this effort in 24 context with the broader staff efforts to develop 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
8 advanced reactor guidance.
1 The development of the instrumentation and 2
control Design Review Guide, which started to identify 3
and apply insights and lessons learned from past new 4
reactor application reviews that are important to be 5
captured and addressed in order for the Agency to be 6
ready for a future new or advanced reactor licensing 7
applications.
8 The Design Review Guide was initiated 9
prior to and for the most part was developed 10 separately from the commission approved Licensing 11 Modernization Project, and before the recent start of 12 activities associated with the industry-led 13 Technology-Inclusive Content of Application Project, 14 or TICAP, and the staff-led Advanced Reactor Content 15 of Application Project, ARCAP, which will provide 16 guidance for risk informing the scope and level of 17 detail of an application.
18 Both TICAP and ARCAP are based on the 19 Licensing Modernization Project. The staff plans to 20 brief the ACRS on the TICAP and ARCAP efforts next 21 calendar year.
22 More recently, as the instrumentation and 23 control guidance was further developed, it 24 incorporated concepts from the Licensing Modernization 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
9 Project. The staff is considering how to integrate 1
this specific I&C guidance into its overall guidance 2
on application content and will continue to ensure 3
that the Design Review Guide remains aligned with 4
TICAP and ARCAP efforts.
5 The staff does believe that the guidance 6
for instrumentation and control provides an important 7
example of how a review can be performed using 8
concepts from the Licensing Modernization Project.
9 We're looking forward to hearing from the ACRS on this 10 important topic, and any insights and feedback that 11 you all may have.
12 If ACRS writes us a letter following the 13 full committee meeting, the NRC will finalize the DRG 14 after we address any issues identified by the ACRS.
15 I would now like to turn the meeting over to Jordan 16 Hoellman to begin the presentation.
17 CHAIR BROWN: John?
18 MR. SEGALA: Yes?
19 CHAIR BROWN: Our intention right now is 20 to provide a letter subsequent to that December 21 meeting. So we'll make sure we contact you with --
22 ensure we have any observations from this meeting and 23 anything else that comes up prior to the December 24 meeting.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
10 MR. SEGALA: Okay. That would be great.
1 CHAIR BROWN: Okay.
2 MR. SEGALA: Thank you.
3 CHAIR BROWN: Okay. Thank you, John.
4 MR. HOELLMAN: Okay. This is Jordan 5
Hoellman. I'm a Project Manager in John's branch, in 6
the Office of Nuclear Reactor Regulation. I'm sharing 7
my screen. I assume everyone can see it.
8 MR. HECHT: I'm seeing only the title 9
chart. Is that what you're displaying?
10 MR. HOELLMAN: Yes.
11 CHAIR BROWN: Slide 1 is what we've got 12 up.
13 MR. HOELLMAN: Slide 1, okay. I just 14 wanted to make sure before I continued. I'm going to 15 move to Slide 2. So I'll provide a brief overview of 16 the I&C Design Review Guide, which provides guidance 17 for the NRC staff to use in reviewing the I&C portions 18 of applications for advanced non-LWRs within the 19 bounds of existing regulations.
20 This guidance leverages the NuScale DSRS 21 Chapter 7 framework while factoring in lessons learned 22 from new reactor reviews. The guidance supports the 23 NRC's vision, strategy, near term implementation 24 action plains, or IAP's. Specifically, the guidance 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
11 supports IAP Strategy 3, which involves developing 1
guidance for flexible regulatory review processes for 2
non-LWRs within the bounds of existing regulations.
3 And to a new non-LWR regulatory framework 4
that is risk informed and performance based. And that 5
features staff's review efforts commensurate with the 6
demonstrated safety performance of non-LWR 7
technologies.
8 So as Charlie mentioned earlier, we'll 9
provide a refresher review of how the DRG is organized 10 around the fundamental principles of redundancy, 11 independence, diversity, determinism, and simplicity, 12 and how the review process will ensure that each 13 principle is met in the design.
14 Then we'll discuss some of the revisions 15 we made to the DRG since our June subcommittee 16 meeting, including the significant revisions to 17 address ACRS observations, and some representative 18 revisions to address the public comments.
19 I would note that the resolutions to the 20 public comments did not impact how the fundamental 21 principles are applied by the reviewer, and did not 22 modify the DRG concepts that were presented during the 23 June 2020 meeting.
24 So I will move onto --
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
12 (Simultaneous speaking.)
1 MEMBER KIRCHNER: This is Walt Kirchner.
2 MR. HOELLMAN: Yes, go ahead.
3 MEMBER KIRCHNER: Just a clarification.
4 On your title slide, it says non-LWR. On this slide, 5
it's advanced reactors. I'm just -- it seems like 6
certainly for I&C, it doesn't matter what the flavor 7
of the reactor is. And you point out that it has to 8
be within existing regulations. So why would this not 9
just apply to all advanced reactors?
10 MR. HOELLMAN: So --
11 MEMBER KIRCHNER: Do you see what I'm 12 getting at? Your title slide says non-LWR.
13 MR. HOELLMAN: I understand what you're 14 saying. And we agree. And we believe that the DRG is 15 technology-inclusive and can be used for any new 16 reactor. The reason, I guess, it's titled as for non-17 LWRs is because it was developed to address the 18 immediate needs associated with the non-LWR community 19 consistent with the Reg Guide 1.233 and NEI-1804, 20 which will be discussed in the next slide.
21 NEI-1804 also has the non-LWR moniker in 22 the title of that document, as well. But I think we 23 believe that if an applicant can demonstrate that the, 24 you know, well, we believe it's technology-inclusive 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
13 in that we can use it in reviewing any new reactor 1
applicant.
2 And I think, you know, as we work through 3
with the Technology-Inclusive Content of Application 4
Project and the Advanced Reactor Content of 5
Application Project, John discussed in his opening 6
remarks that will get fleshed out and we'll be able 7
to, you know, this guidance will be referenced and be 8
able to be used for any new reactor applicant.
9 MEMBER KIRCHNER: That's good Jordan.
10 Okay. I just wanted to -- I thought that was your 11 intent. So thank you for the clarification.
12 CHAIR BROWN: This is Charlie Brown.
13 Walt, thank you for chiming in. I missed your name.
14 I apologize for leaving you out of our counting of 15 members.
16 MEMBER KIRCHNER: That's fine, Charlie.
17 I had technology difficulties getting on on my 18 computer.
19 CHAIR BROWN: All right. Well, one other 20 point relative to your comment, which is quite to the 21 point. The intention with our letter in December is 22 to make that exact point. So if I forget that, make 23 sure you remind me at the full committee meeting.
24 MEMBER KIRCHNER: I will, yes.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
14 CHAIR BROWN: I bet you I won't forget it 1
though. It'll be in the letter that it's our 2
impression that it should be applied across the board.
3 So thanks a lot for bringing that up. Go on, John.
4 MR. HOELLMAN: Okay. Thanks, Chairman 5
Brown. So I'll move onto Slide 3 then. And we 6
certainly understand the comment and I think that's 7
something that, you know, as we move forward with some 8
of our advanced reactor activities, we'll need to 9
align on what we're -- You know NEIMA uses the 10 definition of advanced reactor, I'm not sure where 11 we're going to use that definition, but we definitely 12 agree that the DRG is technology-inclusive and can 13 apply to any new reactor.
14 MR. SEGALA: Jordan, this is John Segala.
15 Just supplement everything, I agree with everything 16 that was said. Just to supplement, you know, we 17 started this whole activity on the DRG before NEIMA 18 existed. We started it before LNP, and at that time, 19 we were, we had a DSRS, a Design-Specific Review 20 Standard for the NuScale light water SMR review.
21 And so we wanted to see, you know, what we 22 could develop in terms of a technology-inclusive 23 approach for non-light water reactors because we 24 didn't have an I&C guidance document for that area.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
15 So we, as Jordan said, we started off working on this 1
document for non-lights specific, because of the gap 2
that we were trying to fill.
3 And then subsequent to that, you know, 4
NEIMA came out and defined advanced reactors to also 5
include light water SRM's and because this was a 6
technology-inclusive guidance, it was very easy to 7
expand the scope to include light water SRM's as well.
8 But there's no reason, as Jordan said, it 9
can be used for any new reactor, regardless because of 10 the technology-inclusive nature.
11 CHAIR BROWN: I'm going to amplify that a 12 little bit. Not only did it -- it really didn't start 13 with NuScale weight. It really, this DSRS concept 14 really evolved out of the ESBWR I&C reviews and the 15 AP1000 I&C reviews. And mPower, the SMR for mPower, 16 actually developed the initial versions of this 17 design-specific review standard, which then was, I 18 guess, mucked around on a little bit and applied to 19 NuScale as well. And it worked well.
20 Also, the concept was applied in the 21 subsequent reviews of the AP1400 and now the NuScale 22 designs. So it's been -- this approach has been used 23 extensively after those first early new design 24 applicants applied, AP1000 and ESBWR. Just a little 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
16 more highlighting.
1 MR. HOELLMAN: Okay. Thanks, Chairman 2
Brown. So I'll continue Slide 3. The NRC has engaged 3
with the Licensing Modernization Project, or LMP that 4
was led by Southern Company, coordinated by the 5
Nuclear Energy Institute and cost shared by the 6
Department of Energy.
7 The LMP's objective is to develop 8
technology-inclusive, risk-informed, and performance-9 based regulatory guidance for licensing non-LWRs for 10 the NRC's consideration and possible endorsement.
11 The LMP document, which is NEI 18-04, 12 outlines an approach for use by reactor developers to 13 select licensing basis events, classifies structures, 14 systems, and components, or SSC's, permits special 15 treatments and programmatic controls, and assess the 16 adequacy of a design in terms of providing layers of 17 defense-in-depth.
18 And SRM SECY-190117, the commission 19 approved the use of the technology-inclusive risk 20 performance based methodology, described as a
21 reasonable approach for establishing key parts of the 22 licensing basis and content of applications for 23 licenses, certifications, and approvals for non-LWRs.
24 The NRC published guide 1.233 on June 9th, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
17 2020, which endorses the principles and methodology in 1
NEI 18-04 as an acceptable method. The methodology 2
described in NEI 18-04 and Regular Guide also provided 3
general methodology for identifying an appropriate 4
scope and depth of information to be provided in 5
applications to the NRC for licenses, certifications, 6
and approvals.
7 The DRG has been coordinated to align with 8
the risk-informed performance-based LMP framework, and 9
provides review guidance on all aspects of safety 10 significant I&C systems, which include safety-related 11 I&C systems and I&C systems that are not safety-12 related but warrant special treatment.
13 Although the DRG aligns with the LMP 14 framework, the DRG also provides the flexibility for 15 NRC staff to perform I&C reviews for applications that 16 do not implement LMP framework, and the staff will 17 continue to ensure that the DRG aligns with the 18 industry led TICAP project, the NRC led ARCAP project, 19 and other advanced reactor initiatives including the 20 future Part 53 Regulatory Framework.
21 So I think that's all I wanted to discuss 22 or highlight again on this slide. So I'll move onto 23 Slide 4 unless there are questions. Okay. On Slide 24 4 and, I think at this point, I'm going to turn it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
18 over to Joe Ashcraft who has a little more broader 1
perspective on the evolution of the I&C guidance 2
throughout the use.
3 MR. ASHCRAFT: Thank you, Jordan. Hello.
4 My name is Joe Ashcraft and I am an I&C Technical 5
Reviewer in NRR. I was part of the team for the 6
development of the NuScale design-specific review 7
guide and mPower, for that matter, for Chapter 7, and 8
the Design Review Guide, DRG, as we currently call it.
9 So starting, as Chairman Brown stated, we 10 started getting these lessons learned with the ESBWR 11 and APR1400. So we've just been, you know, kind of 12 carrying it forward as we went to the ACRS for various 13 certifications.
14 So just to talk about the SRP, I mean, it 15 is still the primary staff guidance and the staff's 16 use of the 2007 revision has been effective for light 17 water reactor reviews. Due to its nature, though, the 18 use of the SRP for new reactors have not been 19 optimized in the past.
20 So the staff wanted to improve how we did 21 I&C reviews for small reactors, remove requirements 22 that no longer applied to SMR's like IEEE standard 23 279, and to remove duplicate reviews of the same 24 requirements as many of the requirements were reviewed 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
19 in each set of chapters of the SRP. And I guess the 1
best example would be independence.
2 I mean we did it for the RPS, the SFAS, 3
and any other safety related, and then we turned 4
around and did it for the non-safety side, looking 5
back. So we thoroughly did reviews of independents 6
many, many times.
7 So the DRS, the commission's policy on the 8
reviewers small modular reactors expects the staff to 9
develop and use design-specific review standards for 10 each application for efficiency and effectiveness. So 11 we took this opportunity to develop the DSRS for I&C 12 that is significantly different from the SRP, the 13 concept of one review or one certain request for 14 additional information as needed.
15 The DSRS reflects the four fundamental I&C 16 design principles plus one concept by having sections 17 for independence, redundancy, predictive, and 18 repeatability, adversity, and defensive depth plus 19 simplicity, which we added as an appendix along with 20 the approved layout and dilution of guidance 21 duplication.
22 It is a simpler, more risk informed, 23 safety focused corporate lessons learned. And our 24 objective was to prove the safety focus of the staff 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
20 reviews by ensuring the applicant has official 1
licensing basis details presented in the application.
2 And to clearly demonstrate that the applicable 3
regulations are met, and the fundamental I&C design 4
principles were addressed.
5 We improved the efficiency of reviews by 6
eliminating unnecessary information from being 7
docketed and reviewed and by improving guidance to 8
avoid unnecessary or repeated RAI's.
9 Note that the use of the DSRS for NuScale 10 has been a huge success. Early availability of it, 11 along with closed per application coordination with 12 the applicant was essential. And unlike other 13 previous new reactor applications, the NuScale 14 licensing review was completed earlier than most other 15 areas of the certification and with no significant 16 challenges.
17 So, you know, bringing everything we 18 learned from new reactors, and even the NuScale, we 19 started developing the DRG. So it is an evolution of 20 the DSRS, or it reflects the safety focus approach 21 from the DSRS, including the four fundamental I&C 22 design principles, plus simplicity.
23 But, it was developed while factoring 24 feedback from the lessons learned initiative by the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
21 I&C staff from the NuScale and APR1400 review, and 1
others. And we provided a spreadsheet of just, you 2
know, the lessons learned that we accumulated over 3
time.
4 So the next slide discusses the goal for 5
this document. So let's go to Slide 5. So the DRG 6
goal is to modernize the I&C safety review in support 7
of advanced non-light water licensing applications.
8 Success within this goal or objective will be 9
reflected by simpler, streamlined, and agile I&C 10 review, and regulatory infrastructure that will 11 effectively address I&C designs for new and advanced 12 non-light water reactors.
13 The I&C DRG was initiated as a proactive 14 way to modernize the I&C safety review of advanced 15 non-light water applications by providing (audio 16 interference) technology-inclusive, risk-informed, and 17 performance-based reviews.
18 As demonstrated by the experience with 19 NuScale I&C review, the staff believes that the DRG 20 guidance will lead to more effective and efficient 21 reviews. Making it available for non-light water 22 designers early will help to establish predictable and 23 efficient I&C reviews processes while the common goal 24 of safety is ensured.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
22 The DRG supports the NRC vision and 1
strategy for advance reactor safety reviews, as it 2
could be used by advanced reactors with vastly 3
different technologies. Also, the DRG allows for our 4
flexible review process within the bounds of existing 5
regulations.
6 The ACRS subcommittee observation from 7
June 2020 and NEI comment 4-2 noted that the DRG 8
methodology could be used for evaluation of any new 9
reactor design, light water or non-light water. And 10 while the staff agrees, the DRG technology-inclusive 11 is technology-inclusive and can be used for any new 12 reactor applicant.
13 It was developed to address the immediate 14 needs associated with the non-light water community, 15 consistent with Reg Guide 1.233 and NEI 18-04.
16 The LMP review framework and terminology 17 cites the significance endorsed Reg Guide 1.233 is 18 factored into the DRG. Again, although the DRG aligns 19 with the LMP framework, the DRG provides flexibility 20 for the staff to perform I&C reviews for applications 21 that do not implement the LMP framework.
22 So Slide 6, please.
23 CHAIR BROWN: Don't go yet.
24 MR. ASHCRAFT: Well, I paused.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
23 CHAIR BROWN: You didn't pause quite --
1 I had to clear my throat there for a minute.
2 MR. ASHCRAFT: Okay.
3 CHAIR BROWN: I just want to make one 4
observation. I mean, it's -- or yes, I guess it's an 5
observation. You don't have to do anything. It's 6
just to make sure we understand that the four goals 7
that you lay out, in terms of the modernization, don't 8
compromise at all the application of the fundamental 9
design principles for safety instrumentation and 10 control systems.
11 All four of the major items that we talk 12 about are consistent with this approach in the 13 modernization. I hope people (audio interference) 14 risk-informed performance-based that all of a sudden, 15 we don't have to have independence, defense-in-depth, 16 redundancy, or deterministic type processing.
17 You're supposed to say we agree. I'm 18 waiting.
19 MR. ASHCRAFT: We agree. Sorry. Jordan, 20 were you agreeing? This is Joe Ashcraft. Yes. I 21 guess we'll see it in the slide, but yes. We agree.
22 CHAIR BROWN: Okay. I looked through the, 23 as I was going through this whole guide, I mean, 24 excuse me, the whole DSRS, I did not see any place 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
24 where it appeared, well, there was a couple which I'll 1
bring up later, which we're going to need to discuss, 2
where I'm going to try to understand whether there's 3
compromise or not. But I'm saving those until you 4
finish.
5 MR. ASHCRAFT: Okay. Yes. This is Joe 6
Ashcraft again. I guess I'd like to just say in 7
general, too, that, you know, so we have what we call, 8
and we'll see on the next slide, the I&C review, but 9
above that is the advance reactor review team. So 10 any, you know, exemptions or whatever that could 11 impact portions or slightly impact, would be addressed 12 there with I&C support, obviously.
13 But generally speaking, we don't envision 14 any, you know, major changes to the four principles 15 and simplicity.
16 CHAIR BROWN: Okay. Thanks.
17 MR. ASHCRAFT: All right. Next slide. So 18 and this is what I was referring to, so if you see the 19 top two, well, let me -- this is our, sort of our top 20 down review approach. And this depicts the flow of 21 reviewer should a full I&C review be required. And 22 kind of, I just mentioned, should there be any 23 exemptions, et cetera, that could impact, you know, a 24 portion of what's inside the blue box, possibly.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
25 The two top bubbles are performed by the 1
core review team, defines the support as necessary.
2 In this review we'll formulate what, if any, of the 3
blue box areas may be needed to be adjusted by the I&C 4
staff.
5 So getting into the blue box area, and I 6
don't know, I think in the last meeting, we didn't 7
really highlight the fundamental principles, as well 8
as we got them here, but you really got it broken down 9
at the almost half, you know, one side will be looking 10 at reliability and the other side, robustness, which 11 would include defense-in-depth
- measures, the 12 fundamental I&C principles.
13 Also qualification measures and then you 14 can see this portion, the supporting attributes 15 quality. That's really done by another chapter, but 16 we are, you know, we coordinate it and we ensure that 17 our equipment falls within the four brands, et cetera, 18 and meets the qualifications that's needed to support 19 the I&C.
20 And on the other side, for liability, I 21 mean, basically, as you can see in this slide, we go 22 down that route. We do that anyway, but we're going 23 to, you know, we'll start seeing more and more self-24 diagnostic features and fail-safe designs and, you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
26 know, that sort of thing. So that's really what this 1
slide is to look at.
2 And then down below, the four principles, 3
we added simplicity, and when you think about it, 4
simplicity really aids in review of independence. If 5
you got an architecture where you've got wires coming 6
and going from all over the place, it just really 7
drags the review.
8 So the more simple your safety design is 9
and that you show the inputs and outputs and how it's 10 not impacted by non-safety say, the easier the review.
11 And at the bottom, we have the PDC's, which 12 essentially are, you know, modified GDC's, but they're 13 called PDC's. And we also have our other consensus 14 standards and applicable NRC regulations and guidance 15 documents.
16 And at the bottom, this just really shows, 17 we did it more in the DSRS than we've probably ever 18 done in other reviews. Well, I say that but we really 19 interfaced with all the other chapters more, and you 20 saw it with the boron distribution issue, and others.
21 But I mean, we really interfaced better with the other 22 chapters for the NuScale review and we plan to carry 23 that going forward because we feel that that's really 24 beneficial and it's helped a lot.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
27 So I'll pause just a moment.
1 MEMBER BLEY: Yes, thanks. This is Dennis 2
Bley. Well we used to have simplicity as one of our 3
principles. We kind of gave up because the industry 4
sort of missed the opportunity for that early on, that 5
with some of the new designs, maybe we can get back to 6
it. I think all of us agree, that's the best first 7
step that we can take to meeting all the others.
8 MR. ASHCRAFT: Right. And I agree. And 9
what happens, so for the NuScale DSRS, I mean, we 10 really didn't have a regulation to slap on it, per se, 11 so that's why we moved it to an appendix. But we 12 stress simplicity, just like we stress review of the 13 architecture.
14 So you know, as we interface with new 15 applicants, we stress the simplicity aspect of it, you 16 know. There might not be a lot of gotchas or RAI's, 17 but I mean, the more simplistic thing they can design, 18 the easier it's going to get through a review. And 19 maybe that's our best seller in that regard.
20 But yes, we found from the NuScale, both 21 review and architecture up front, and, you know, the 22 review and the simplicity of their design really, 23 really aided in getting through their review with a 24 safety evaluation approved.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
28 Okay. Let's go to next slide. So this is 1
our review approach and as you can see, we start with 2
the architecture. We try to get in as soon as we can.
3 I mean, every advanced reactor meeting that I was 4
going to before, and even now, you know, they're 5
talking fields and stuff, and I always try to pop in.
6 Hey, I haven't seen your architecture, you know, you 7
got to be working on it.
8 So we feel that we're going to focus on 9
the architecture and system functions availability, 10 and hopefully this portion of the review has started 11 during the pre-app meetings. Then we go, the second 12 the staff reviews focuses on safety, slight risks, 13 significant functions, and selected structures, 14 systems, and components that support them to ensure 15 that the NRC performance objectives are met.
16 And then lastly, you know, they do staff 17 reviews efforts on the SSC's that are not safety 18 related, without special treatment, specifically the 19 staff review focuses on ensuring that these SSC's will 20 not inhibit performance of safety significant 21 functions.
22 And, you know, and I say this, so all the 23 designs coming in, you know, they've got different, 24 you know, designs and I&C's different, and, you know, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
29 the non-safety, safety, so, you know, I say it's 1
reduced or less, but I mean, this is actually just as 2
important as any of the rest.
3 So let's go to Slide 8.
4 CHAIR BROWN: Can you back up a minute?
5 MR. ASHCRAFT: Sure.
6 CHAIR BROWN: I just wanted to emphasize 7
just a thought of why the committee started taking 8
this approach of focusing so hard on the architecture 9
back in the ESBWR days, in 2008, and '09, and '10.
10 Took almost two years to get through that. And a 11 well-defined architecture where you see and can 12 confirm that independence, is critical to almost 13 satisfying and understanding why that system is going 14 to be reliable and robust, particularly from a 15 defense-in-depth standpoint.
16 If you don't know what your architecture 17 is crisply and cleanly, it's difficult to know where 18 you need to apply more defense-in-depth. A good 19 architecture that meets all four principles has 20 anywhere from five or six defense-in-depth mechanisms 21 built into it. Then you can focus on what other 22 critical areas might compromise that.
23 Without the architecture, you're lost.
24 And that's why we've been pretty pleased with the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
30 evolution and how we've developed, the staff has run 1
with this and developed this overall approach. But 2
the architecture is just critical for every aspect of 3
ensuring that you're going to be able to accomplish 4
each of the goals.
5 I just wanted to get that in for the 6
record purposes.
7 MR. ASHCRAFT: This is Joe Ashcroft again.
8 And to piggy-back on that, Chairman Brown, I'm so used 9
to calling you Charlie. But Chairman Brown. Last 10 year, we did an audit for the Kairos project at the 11 time they were coming in, I don't know where they're 12 at. But we did an audit of their architecture and I 13 guess they had a few guys from the NuScale that was 14 part of that team.
15 But they really did a good job of laying 16 out their architecture and their drawings, et cetera.
17 So we're pleased with the message that has gone out 18 and we're starting to see it as we interface with, you 19 know, various applicants or potential applicants.
20 CHAIR BROWN: That's good to hear. Thank 21 you.
22 MR. ASHCRAFT: All right. Slide 8 please.
23 So this is going to be long and winded, but I'm going 24 to kind of go through each of these redundancy 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
31 independence, diversity, and determinism, which we 1
call predictability and repeatability. And then 2
simplicity.
3 So a lot of this is straight out of DRG so 4
if at any point, you want me to go on, that's fine 5
too. So redundancy, and I know at the last 6
subcommittee meeting, there was some observations on 7
some of the words that, you know, were a little bit 8
vague. Charlie just addressed earlier about, you 9
know, what we will be doing in our I&C review.
10 So we modified that, as you probably saw, 11 Charlie, because I know that you probably zoned in on 12 that. But anyway, let me just start with redundancy.
13 I mean, the redundancy review, we'll evaluate the 14 level of redundancy used to the safety related system 15 to ensure that no single failure results in a loss of 16 safety function and removal from service of any 17 component or channel does not result in the loss of 18 the required minimal redundancy, unless the acceptable 19 reliability of operation of the I&C design can be 20 otherwise demonstrated.
21 And you know, so that applicant should 22 address the single failure criteria, if applicable, 23 and I&C architecture description should be described 24 on how redundancy is implemented in the I&C system 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
32 design.
1 The applicant then addresses the single 2
failure criteria. They identified any potential 3
safety failures in the system as part of the safety 4
I&C hazard analysis and using measures, such as 5
redundancy, to address these single failures.
6 The reviewer should confirm that the 7
application includes an evaluation of the effects of 8
each component failure mode on the overall system.
9 Any component failure mode that could contribute to a 10 failure of the safety related system is identified, 11 and the design of the safety related system precludes 12 single failure from resultant spurious actuations and 13 necessary actions taken to eliminate, prevent, or 14 control failure modes.
15 And the reviewer should confirm that 16 application provides information sufficient to 17 demonstrate that all SSC's needed for a safe shutdown 18 is defined for each facility, are sufficiently 19 redundant to address single failure criteria, and the 20 use of shared data networks among multiple safety 21 divisions is the single pass for multiple signals or 22 data raises concerns about the extensive consequence 23 of failure as a result of a single failure.
24 So that goes back to the architecture, you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
33 know, we'll see that there. So let's get into 1
independence. And this is --
2 CHAIR BROWN: Joe?
3 MR. ASHCRAFT: Yes?
4 CHAIR BROWN: When you talk about 5
redundancy, you mentioned the words several times, 6
single failure. Later in the document, Reg Guide 7
1.233 is brought out and effectively says you have to 8
evaluation whether you're going to use single failure 9
criteria or not. It effectively says you can design 10 your systems without paying any attention to single 11 failure.
12 How in the world are you going to review 13 to confirm single failure doesn't apply? Has any 14 thought been given to that? There is no standard.
15 There's no guidance for doing that.
16 MR. ASHCRAFT: Well, yes. And I was 17 trying to state it up front. So the advance core 18 review team, should an applicant come in and say, you 19 know what, we don't need to do a single failure 20 criteria. And I'm not saying, we haven't seen any, 21 but I'm not saying we're not. But we will have to 22 look at that very up above the I&C portion, and I 23 think I&C would be involved as part of that review to 24 determine that and like you just stated, maybe that's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
34 something that we're going to have to, you know, 1
create something to better define how we would 2
evaluate that.
3 But assuming it doesn't, you know, get 4
into the I&C review, then we would review it as we 5
always do. But if it does, you know, if their design 6
is such that their claiming and we agree, then that's 7
where that would be a -- I can't think of the words.
8 But that's where they would, that would be done up 9
front and I guess, as you say Charlie, we probably 10 need to create something that would help us, should we 11 see an applicant come in claiming that.
12 CHAIR BROWN: It would be interesting.
13 Effectively, that says you can have a single channel 14 or maybe no channel.
15 MR. ASHCRAFT: Yes.
16 CHAIR BROWN: If you really want to go to 17 the extreme. I'm being a little bit extreme when I 18 say that. But a single channel was kind of --
19 regardless of what type of marvelous, safe, never will 20 fail, never will break, and will never have any 21 problems, the people advertised, it's kind of hard to 22 believe that a reasonable level of redundancy and 23 independence of those redundant protections, or safety 24 systems, are not going to be needed.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
35 Anyway, that's just a thought. But how do 1
we do that?
2 MR. ASHCRAFT: And I agree Charlie. We'll 3
take that observation --
4 (Simultaneous speaking.)
5 CHAIR BROWN: I'm not saying you got to 6
put it in this. It's just think about it for the long 7
term. That's all.
8 MR. ASHCRAFT: I agree.
9 MEMBER BLEY: This is Dennis, Dennis Bley.
10 I got to chime in a little on here.
11 CHAIR BROWN: That's fine.
12 MEMBER BLEY: There's no way one meets the 13 kind of reliability needs you're going to have, if you 14 don't have those things. They're the simplest set of 15 things to get you a highly reliable system. So I 16 can't imagine that anybody would try it and I can't 17 imagine they'd succeed if they tried it because they 18 won't be able to show they have good reliability.
19 CHAIR BROWN: One of the sections in the 20 DRG, Dennis, actually talks about single failure, in 21 1.233. I've forgotten what section it is.
22 MEMBER BLEY: I understand.
23 CHAIR BROWN: Yes.
24 (Simultaneous speaking.)
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
36 MEMBER BLEY: Single failure is no form of 1
meeting redundancy requirements and, you know, you 2
just can't get there without those kinds of 3
requirements.
4 CHAIR BROWN: Exactly. That's my thought 5
exactly. That's why I was a little bit concerned with 6
having it in there, but it meets the overall guidance 7
of the SECY's and the SRN's and the NEI document and 8
the new Regular Guide that just went out. It's out on 9
the street now, I guess. It's no longer a draft 10 guide.
11 MR. ASHCRAFT: This is Joe Ashcraft. So 12 in some of the earlier meetings with stakeholders, and 13 this was on the advanced reactor, not necessarily the 14 DRG. But that was one of the comments of, you know, 15 of being able to design that out. And at the time, I 16 just replied, well, it's part of, you know, 10 C.F.R. 17 or IEEE 603 requirements. So it would have to be an 18 exemption and, you know, they would have to, you know, 19 provide why they feel it's not needed.
20 And, you know, like you said, I just think 21 that would be a hard way to go. But it's something, 22 as with any requirement, if, you know, they could use 23 to show how they meet it differently.
24 CHAIR BROWN: Okay. You can go on.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
37 MR. ASHCRAFT: Yes. I agree. So back to 1
Slide 8. I think it's Slide 8.
2 CHAIR BROWN: Yes, you're on independence.
3 MR. ASHCRAFT: Right. Okay. Yes.
4 Something popped up and I didn't see it. Okay. So 5
independence. So the reviewer is to evaluate the 6
methods described in the application used to 7
demonstrate independence of the I&C systems between 8
redundant portions of the safety related systems, such 9
as redundant safety systems, the safety related 10 systems and the effects of LBE.
11 And between safety related systems and 12 systems that are not safety related. So more 13 appropriate, the staff review should assess the role 14 of independence in I&C systems designated as not 15 safety related, but warranting special treatment. And 16 we would also evaluate the physical and logical 17 interfaces with I&C system design, include specific 18 information sent and the purpose of the information, 19 and the main sending the information. Example, 20 hardware or data communications -- hard wire or data 21 communications.
22 This review clears not only permanent 23 interfaces, but also temporary connections for 24 maintenance and workstations.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
38 The reviewer should evaluate whether 1
there's sufficient electrical isolation equipment 2
belonging to different safety divisions, safety 3
related systems and systems that are not safety 4
related, such as the electrical fault originating from 5
one safety division, or equipment that is not safety 6
related cannot promulgate into another safety 7
division, or safety related system respectively.
8 So if so, the design assures that such a 9
fault would not adversely impact a safety function.
10 The reviewer should verify that any electrical 11 isolation devices or measures installed to prevent 12 electrical fault promulgations are qualified as part 13 of the safety related system.
14 The reviewer should evaluate whether 15 sufficient communication independence between 16 equipment belonging to different safety divisions, the 17 safety related systems, and systems that are not 18 safety related, such as communication failures 19 originating from outside a safety division cannot 20 adversely impact the safety function.
21 This evaluation should include 22 identification of potential failures in the 23 communications mechanisms and information that is 24 being communicated, and the verification that adequate 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
39 controls have been implemented to address these 1
potential failures.
2 The reviewer should verify that no safety 3
division is adversely influenced by information 4
received from outside the safety division. This 5
includes verifying that spurious actuation of I&C 6
equipment due to credible failures or consequential 7
actions of systems that are not safety related, will 8
not adversely impact the safety function.
9 And the reviewer should verify sufficient 10 measures, use of buffer mechanisms are implemented to 11 minimize (audio interference) fault promulgation and 12 to increase the reliability of the information being 13 communicated.
14 The reviewer should also verify there's 15 adequate functional independence, if needed, between 16 the equipment belonging to different safety divisions, 17 and safety related systems, and systems that are not 18 safety related. Such that a division does not rely on 19 information from outside the safety division to 20 perform a safety function. To reduce potential 21 hazards associated with resource sharing functions 22 that are not necessarily for safety should be executed 23 outside the safety related system.
24 So let's move onto diversity.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
40 CHAIR BROWN: Can you back up?
1 MR. ASHCRAFT: Sure.
2 CHAIR BROWN: When you talk about -- I 3
didn't, I'm not quite sure where I was going to make 4
the comment. Part of the means to achieve 5
communications independence. I mean, there's a lot of 6
communication, you know, between safety systems and 7
then the systems that they actuate in some 8
circumstances, which are to control and/or safeguard 9
systems. And/or any other non-passive or passive 10 initiating systems that we may have in the future.
11 And you did address this back in the 12 appendix about unidirectional communications outside 13 the plant. But some of those, if you look at NuScale, 14 for instance, we had unidirectional communications 15 from the safety off to the systems they did need to 16 actuate anything. So they combined it in two 17 different ways.
18 You didn't talk about, if you don't have 19 unidirectional in some cases, you can't, you won't 20 have independence if it's software type 21 communications, other than hard wired. And a bistable 22 signal is quite safe. But a software signal is not if 23 it's bidirectional.
24 I kind of, I didn't say anything, I did 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
41 not make a comment based on the independence section 1
of you all's X.2.2 point whatever. Okay? Sufficient 2
communication independence. But not in every 3
circumstance, but in some circumstances, the 4
communication out of the safety
- systems, the 5
unidirectional is a critical item. And you addressed 6
it in the appendix but it was not reflected up either 7
in the predictability and, what did you call it?
8 Predictability and repeatable behavior.
9 CHAIR BROWN: Right.
10 (Simultaneous speaking.)
11 CHAIR BROWN: Or in the independence. It 12 is in the appendix, I think, I forgotten where. It's 13 A-9. Yes, in section A-9.
14 MR. ASHCRAFT: Right. Well, we'll take 15 that back as an observation to see if we need to move 16 it up there somewhere to highlight it more.
17 CHAIR BROWN: Well just a reference to 18 the, you know, the concept in the appendix.
19 MR. ASHCRAFT: Right.
20 CHAIR BROWN: Independence gets hefted by 21 utilizing and then reference the appendix. We don't 22 need to, you know, put the -- repeat the stuff all 23 over the place. Just reference the appendix where 24 that information is contained.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
42 MR. ASHCRAFT: Understood.
1 CHAIR BROWN: Okay. Seemed to me in the 2
predictability and, you know, 2.2.1.4, and behaviors 3
section, and the independence section, that might be 4
a place where you want to just reference that 5
particular part of the appendix, which I think is A-9, 6
or something like that.
7 Right. It is A-9. And we'll get to that 8
section later in the slides. But thank you for that 9
and we'll take that observation down.
10 MR. ASHCRAFT: Okay. Thank you. So, 11 let's continue with diversity. So the reviewer should 12 evaluate the common cause failure analysis results 13 provided by the applicant to verify the potential CCF 14 due to a latent systematic fault within the digital 15 I&C will not result in exceeding the apical 16 radiological release limits.
17 In performing this evaluation for each 18 even evaluated in the safety analysis, the applicant 19 should perform a D3 assessment to determine whether a 20 potential common cause failure due to systematic 21 faults in the digital I&C could disable a safety 22 function and a diverse means not subject to the same 23 common cause failures available to perform either the 24 same function or a different function, such that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
43 radiological limits are met, or not exceeded.
1 Note that the overall analysis of LBE's 2
and related defense-in-depth assessments for safety 3
functions may include the potential contributions from 4
I&C systems.
5 So you know, we're going to identify, 6
identification of digital I&C systems that are 7
vulnerable to a CCF analysis of plant response to 8
demonstrate the radiation release due to a CCF of the 9
digital I&C system for each of the events evaluated 10 and accident analyses do not exceed the limit. The 11 integrity of the functional containment, should there 12 be
- one, as described in applicable PDCs as 13 demonstrated.
14 A demonstration for each postulated common 15 cause failure that could disable a safety function 16 within the digital I&C system concurred with each 17 event evaluated in the plant safety analysis. A 18 diverse means as it's been identified to provide a 19 diverse and different function. This diverse means 20 could be an automatic function or a manual operator 21 action provided the applicant has demonstrated that 22 reliable equipment is accessible and available to 23 perform the function, and the operator and equipment 24 will perform the function within the response time 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
44 credited to perform these actions.
1 Equipment that is not safety related can 2
be used to provide a diverse means provided it's 3
sufficient quality to perform the necessary function 4
under associated vent conditions in an allowable 5
manner.
6 The equipment performing the diverse or 7
different function is diverse and independent from the 8
system, subject to the common cause failure, and if 9
diversity within the system is credited as providing 10 the diverse means of accomplishing the safety 11 function, analysis should be provided to demonstrate 12 adequate diversity within the system, such as 13 diversity of tools used to configure and program each 14 diverse portion of the system, human diversity and 15 implementation of each diverse portion of the system.
16 If other means are credited to address 17 vulnerabilities to common cause failures, these means 18 should be identified and their effectiveness to 19 eliminate common cause failure vulnerabilities from 20 further consideration should be demonstrated.
21 Provisions of a set of displays and controls located 22 in the main control room for manual system level 23 actuation of critical safety functions and monitoring 24 of parameters that support a safety function.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
45 These displays and controls should be 1
independent and diverse from the digital I&C system 2
identified in the part of the discussion about, that 3
talked about diversity, well, item five and six, which 4
would be in the DRG.
5 So let's move onto determinism, a.k.a.
6 predictability and repeatability. The reviewer should 7
confirm that the application provides a detailed 8
timing analysis describing how the I&C systems that 9
support the safety significant functions, including 10 support of communication systems, address the concept 11 of predictability and repeatability.
12 The reviewer should confirm that the 13 application provides sufficient information. For 14 example, in the form of architectural descriptions, 15 functional block diagrams, description of operations, 16 to demonstrate that the proposed digital I&C real time 17 performance is predictable and repeatable.
18 Just a few items. The digital I&C system 19 timing analysis identifies limiting response times, 20 digital system timing requirements, architecture 21 design constraints. The digital I&C timing analysis 22 addresses all system components from signal collection 23 to completely of protective action, e.g., sensor 24 transmitter, logic processor, data communication 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
46 equipment, et cetera.
1 The timing of specific system responses 2
credited in the safety analysis has been allocated to 3
the digital logic portion of the system as 4
appropriate, and has been satisfied in the digital 5
system architectural design.
6 And just to highlight that, I mean, so in 7
your exit analysis, you may have two or three seconds 8
to perform that safety function, but the I&C digital 9
response could be -- is typically in the microseconds 10 or milliseconds, as a minimum.
11 The digital I&C system timing analysis 12 demonstrates that the safety significant functions are 13 achieved within the times credited in the safety 14 analysis. Data communications in support of safety 15 significant functions operate in a predictable and 16 repeatable manner. Data communication is cyclic. No 17 event driven data communications fixed size and 18 predefined data packets.
19 Design practices that do not implement 20 rigorous real time as well as predictable and 21 repeatable performance in the digital I&C's are 22 documented. For those practices identified, verify 23 that the methods used for assessing the risk 24 associated with such design practices have been 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
47 documented and such practices cannot affect the safety 1
functions and the design is not adversely impacted in 2
a safety significant function.
3 So I'll end up this slide with simplicity.
4 CHAIR BROWN: Can you back up a second?
5 MR. ASHCRAFT: Sure.
6 CHAIR BROWN: Under the deterministic 7
part, and I may have jumped in earlier, not exactly 8
the same way. But in your section, Appendix A, there 9
is the section on logic processing units being 10 monitored by an independent hardware based diverse 11 means.
12 MR. ASHCRAFT: Yes.
13 CHAIR BROWN: Okay. That's Section A-9, 14 also. I think it's one of the items. This, that's 15 really part of the predictable and repeatable behavior 16 also in order to make sure it's predictable and 17 repeatable. So it doesn't lock up.
18 Again, a reference would be useful that 19 that is covered in the appendix, as well. That's 20 another observation.
21 MR. ASHCRAFT: Okay. Noted.
22 CHAIR BROWN: I'll send you all a copy of 23 these more detailed comments, or observations, via 24 Christina after the meeting. As soon as I get them 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
48 into the record.
1 MR. ASHCRAFT: Okay. Thanks, Chairman 2
Brown. All right. So let's finish up this slide with 3
simplicity.
4 CHAIR BROWN: Actually, I was talking 5
about the --
6 (Simultaneous speaking.)
7 MR. ASHCRAFT: Yes. I was going to say 8
that but I didn't' want to, you know, extend the 9
conversation.
10 CHAIR BROWN: That's okay. It's all these 11 other buzzwords, it's really the watchdog.
12 MR. ASHCRAFT: Exactly.
13 CHAIR BROWN: Thank you.
14 MR. ASHCRAFT: Okay. For simplicity, so 15 while review guides for simplicity is not explicitly 16 provided, the reviewer should verify that the 17 applicant has incorporated this concept in design.
18 And this includes verifying that unnecessary functions 19 and interfaces are not included in the design. They 20 could challenge the conformance to the fundamental I&C 21 design principles.
22 And measures are included to assure I&C 23 systems that are not safety related do not present 24 electronic path, which is unauthorized changed plant 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
49 software or display erroneous plant status information 1
to the operators.
2 So in a way, I mean, simplicity really 3
just aids in being able to look at independence, et 4
cetera. So they all work hand in hand. And the more 5
complex a system, the harder it is to do an evaluation 6
on.
7 So let's go to the next slide. Slide 9.
8 Okay. So this is one of the ACRS observations from 9
the June 2nd meeting. So we revised, to be more 10 explicit, about the communications plan. As a result, 11 as you can read it here, and I could read it if you 12 like. But this is the change that we made into Item 13 6 of the Section X.0.1.2. It really highlights the --
14 enforce the unidirection communication features.
15 CHAIR BROWN: Joe?
16 MR. ASHCRAFT: Yes. I'm pausing. I know 17 you got something to say, Chairman.
18 CHAIR BROWN: No, no. This is fine. I 19 had no problem with this. It's just that that is an 20 important feature and that was not reflected in any 21 section in the appendix, and I thought something that 22 mentions or observes this particular thought process 23 should be in, I think, Item 6, A-6, as in concert with 24 either Items 2 or 3 back in the appendix.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
50 MR. ASHCRAFT: Okay.
1 CHAIR BROWN: But the appendix, that part 2
of the appendix, I've forgotten what in the world that 3
says. That's under automatic and manual control. No.
4 That's the wrong one. What did I just say.
5 (Simultaneous speaking.)
6 CHAIR BROWN: I got the wrong one. I 7
apologize. Hold on. No. It's just, it's what you 8
have, it's that paragraph reflected back in A-6.
9 That's all. I didn't have any more on that.
10 MR. ASHCRAFT: Okay. Yes. We'll take a 11 look at the DRG and the appendix to see if, to include 12 effective pointers. So thank you for that comment.
13 Next slide. Slide 10. So this was a 14 serious observation on manual controls. We revised it 15 to what is covered in their guide, 1.62, and the 16 change that we made to the DRG, specifically the 17 statement shown and the slides were copied from the 18 Regular Guide 1.62 under the -- meeting the BTP 7-19 19 guide and section.
20 And this is based on the Commission's 21 direction documented in the SRM SECY-93087, which 22 includes a statement such as the following. The 23 displace you control will be independent and diverse 24 from the safety computer system identified in Items 1 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
51 and 3 of the SRM.
1 So we added this, revised this section to 2
reflect what you see on the screen.
3 CHAIR BROWN: I do have a comment on that.
4 I'm trying to find it now. Oh, that is reflected, 5
that particular item -- 089, right? This, I guess I 6
don't understand or actually I disagree. You say 7
manual controls may be connected either to discrete 8
hardware and hard wired components, or to simple 9
dedicated and diverse software based.
10 Now we're going to introduce software back 11 into the manual operation. And that does not make a 12 whole lot of sense to me. And I may have missed it in 13 an earlier version. I think I went back and checked 14 and couldn't find it. That's been added. And I guess 15 I would have taken a different approach to saying 16 that, relative to you can connect it to simple 17 dedicated discrete hardware logic components, but not 18 software based logic components.
19 That just, it blows my mind that we've now 20
-- we've gone and said manual operations should be 21 downstream of software, but that we're going to use 22 software to complete the operation. That's kind of an 23 inconsistent thought.
24 MR. ASHCRAFT: All right. So we're, you 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
52 know, we're thinking to consider, but keep in mind, 1
well, the goal here is for an independent diverse from 2
the digital I&C safety. So we're thinking of maybe 3
changing that last sentence. But it may not answer 4
your comment. But should confirm that the manual 5
controls are independent and diverse from the digital 6
I&C safety systems.
7 CHAIR BROWN: Yes, but you still got 8
software. You're now down to software that is single 9
channel, when you talk about diverse software basis.
10 It's a different type of software, but it's a single 11 channel by the time you get down to turning stuff off, 12 or turning it on.
13 MR. ASHCRAFT: Right. I mean --
14 CHAIR BROWN: You have no redundancy in 15 that or anything else on that. And that's the purpose 16 of going back to hard wired switch type control.
17 Whereas, you can go to a hard wired digital logic, 18 which I think NuScale did in their priority logic 19 units.
20 MR. ASHCRAFT: Right. Well, we'll take 21 this observation back. I think what -- I thought what 22 we tried to do was incorporate what was in Regular 23 Guide 1.162, but, you know, your concern, we'll take 24 back.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
53 CHAIR BROWN: Yes. I don't remember that 1
being in 1.162. If it is, we should've scrubbed it.
2 I was, I missed it when we reviewed that.
3 MR. ASHCRAFT: Well, it's under the 4
meeting, the BTP 7-19 guidance section. But we'll 5
take a look at it, Charlie.
6 (Simultaneous speaking.)
7 CHAIR BROWN: I've got a problem with that 8
in BTP 7-19 as well.
9 MR. ASHCRAFT: Well, and you know, that's 10 a good point I'll just make. You know, as some of 11 these other things, like BTP 7-19 and et cetera, I 12 mean, we're trying to keep ahead, or maybe -- well, we 13 are ahead, but you know, the changes in those type of 14 documents could cause revisions in what we're doing 15 here.
16 So we're constantly keeping up with what 17 all is going on in the digital I&C world. So next 18 slide, 11.
19 So we had 69 public comments, 46 resulted 20 in some type of change to the DRG, and the resolutions 21 to the public comments really didn't modify the DRG 22 concepts that were presented during the June meeting, 23 including how the fundamental principles are applied 24 by the reviewer.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
54 I just want to note that the industry, 1
NEI, indicated its positive feedback on the DRG. They 2
commended the staffs safety focus, risk informed, 3
performance based, technology neutral approach, a lot 4
of the LMP, as well as the core review team approach 5
that we used.
6 In addition, it stated the issuance of a 7
design review guide on instrumentation controls for 8
the new reactors will be -- will contribute to 9
regulatory stability and clarity.
10 So we reviewed each of the public comments 11 and I think we provided you with the comment 12 resolution file. And if it's not public, it should be 13 soon, I believe. But --
14 CHAIR BROWN: You couldn't tell us in this 15 slide how you incorporated this?
16 MR. ASHCRAFT: Well, I'm getting to that, 17 Chairman.
18 CHAIR BROWN: Okay. I read your response 19 and it's really murky.
20 MR. ASHCRAFT: Well, okay. Sorry about 21 that.
22 CHAIR BROWN: I'll let you go ahead and 23 give the response. And then I'll murky-ize it for 24 you.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
55 MR. ASHCRAFT: You're trying to throw me 1
off my game here.
2 So I just want to say, we reviewed all the 3
public comments and despite the number of comments, I 4
just want to reemphasize that the resolution of the 5
comments resulted in clarifying DRG content versus 6
making any substantive or drastic changes to the 7
document.
8 So for this particular slide, this was 9
their comment, and what, you know, so they were 10 saying, well, you see what they're saying. They 11 thought maybe we should somehow better describe the 12 definitions of fundamental I&C design principles. So 13 our response was, is so we disagreed with the proposed 14 change and the term fundamental I&C design principles, 15 which were first defined and explained in the NuScale 16 DSRS Chapter 7, Section 7.1 and we give the ADAMS 17 number.
18 And it's used in the same manner in the 19 DRG as an evolution from the NuScale, DSRS. And so 20 what we did do, so this fundamental I&C design 21 principles could be used as a vehicle for meeting 22 PDCs, but are not equivalent.
23 So what we changed is in, and maybe we 24 didn't say the section, but there's a section that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
56 just pointed to the NuScale DSRS Chapter 7, but we 1
added Section 7.1 so that you could go right to 7.1 2
and see that all of the design principles were --
3 CHAIR BROWN: Let me just -- the reason I 4
say this is fuzzy, I think you should have been more 5
forthright. In fact, I went back last night and went 6
through the entire DRG and found eight or nine actual 7
statements of fundamental I&C design principles 8
followed by the string of redundancy, independence, et 9
cetera, et cetera.
10 And then section X.2.2.1 provides a 11 discussion on each one of those principles. So I'm 12 trying, I'm having a really hard time understanding 13 why any industry did not understand what the 14 fundamental design principles were. And that -- I 15 don't understand why you didn't tell them that.
16 Adding this reference to another NuScale DSRS where 17 they can go look it up is not very useful to them.
18 But you've got it throughout the document.
19 And you got the whole section on the 20 independence, redundancy, et cetera, et cetera, et 21 cetera, discuss in great detail what you mean by the 22 design principles. So I think you could have been 23 more pointed in your response. That's all.
24 MR. ASHCRAFT: Understood. And I guess we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
57 took the comment. I mean, obviously, they read the 1
DRG itself where we discussed all the I&C design 2
principles. But I guess it just seemed like they were 3
asking, like where did all this come from.
4 CHAIR BROWN: This is the best discussion 5
of all those design principles that's in any document 6
so far.
7 MR. ASHCRAFT: Right.
8 CHAIR BROWN: For the most part. I mean, 9
it's in the NuScale one and it's in the mPower to some 10 extent.
11 MR. ASHCRAFT: Yes.
12 CHAIR BROWN: Those were made better as 13 you all went along. But anyway, it's fairly clear how 14 it's defined. That's all. So I'm not objecting to 15 you all's disagreement, I just don't understand when 16 they say it's described in X.2.2.1. Is this the 17 intended definition? Well, my answer would have been 18 yes.
19 MR. ASHCRAFT: Right. Okay.
20 CHAIR BROWN: Anyway, you can go onto the 21 next one.
22 MR. ASHCRAFT: All right. Thank you.
23 CHAIR BROWN: That one's even better.
24 MR. ASHCRAFT: Right. So let's go to the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
58 next slide. Slide 12. So this was the comment, and 1
if you notice down in the bottom portion that's red, 2
those were the actual changes that they wanted made to 3
the DRG.
4 So our response was, so we partially 5
agreed with the comments. Specifically, we added the 6
fundamental safety to the identified sentence as 7
proposed. However, the staff does not agree with 8
adding a reference to the IAEA technical report, as is 9
NEI 18-04, which is referenced in the DRG, includes 10 and defines the term fundamental safety.
11 So a lot of their comments and, you know, 12 we provided, if there's any others you'd like to go 13 through. I mean, they were sort of in that sort of 14 vein. You know, we did make some minor revisions, but 15 overall, like I said up front, there was nothing major 16 that needed to be changed in the DRG.
17 So let's go to slide -- well, I'll pause 18 just for a minute.
19 CHAIR BROWN: Somebody else got a comment?
20 MEMBER BLEY: Charlie?
21 CHAIR BROWN: Yes, go ahead.
22 MEMBER BLEY: It strikes me, what they 23 were saying is that this section isn't labeled 24 fundamental principles. It's labeled something else.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
59 MR. ASHCRAFT: You're back to Slide 11?
1 MEMBER BLEY: I'm back to the old one 2
because that hadn't jumped out at me, and after 3
Charlie's tirades, I went back and looked. And I 4
think their objection was you didn't title that whole 5
section fundamental principles, in which case they 6
would have known those were the fundamental 7
principles. That's all.
8 MR. ASHCRAFT: All right.
9 CHAIR BROWN: That's a good point. Thank 10 you, Dennis. I didn't think of that.
11 MR. ASHCRAFT: We'll take that observation 12 back.
13 CHAIR BROWN: It should be an easy one.
14 MR. ASHCRAFT: I wish that all your 15 observations were that easy.
16 CHAIR BROWN: Well, I've got more that 17 won't be easy.
18 MR. ASHCRAFT: All right. So let's go to 19 Slide 13.
20 CHAIR BROWN: Do you want my comments 21 before, or do you just want to cover your milestones 22 before I interrupt.
23 MR. ASHCRAFT: Well, we've got to --
24 CHAIR BROWN: That slide.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
60 MR. ASHCRAFT: Well, the last slide is 1
questions. And I guess I should have put more 2
observations or comments, but yes, let's just finish 3
up with the milestones.
4 CHAIR BROWN: Okay. That's fine.
5 MR. ASHCRAFT: So I mean, this is just, 6
you
- know, we completed our public and ACRS 7
observations, and we're having our
- meeting, 8
subcommittee, today. We've got the full committee 9
scheduled in December sometime and we plan to 10 incorporate ACRS recommendations and prepare and issue 11 the final DRG sometime, you know, whether it's the 12 first quarter or the first part of 2021. We plan to 13 get it out as soon as possible after we, you know, 14 resolve the ACRS comments.
15 So I will go with that to the next slide.
16 So this, Charlie, Mr. Chairman Brown, is where you can 17
-- if you need to go back to some of the other slides, 18 that's fine too.
19 CHAIR BROWN: No, we probably don't have 20 to but you may need to have, hopefully, you've got 21 your document with you somewhere that you can look at 22 because I do have some detailed big issues that you 23 changed. One of them I missed from the June meeting, 24 and I apologize for that. But I'm going to bring it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
61 up now.
1 It's almost 11:00, do any members -- would 2
anybody like to take, before we dive into this, might 3
take a half an hour, 45 minutes or so, take a break 4
before we do that? I know Walt and I normally like to 5
take our breaks. I'm sorry to ping on you Walt.
6 MEMBER BLEY: Good idea, Charlie.
7 MEMBER KIRCHNER: That's a good idea, 8
Charlie. Ms. Lucy is looking at me like it's time.
9 CHAIR BROWN: I understand what Ms. Lucy 10 means.
11 (Simultaneous speaking.)
12 CHAIR BROWN: We'll take a, what time is 13 it? 11:00, 10:50? We've got some time so why don't 14 we take a break until 11:15. That way everybody can 15 let their dog out and everything, get another cup of 16 coffee, et cetera. Is that okay?
17 MR. ASHCRAFT: Yes.
18 CHAIR BROWN: 11:15 eastern standard time.
19 MR. ASHCRAFT: It's a deal.
20 CHAIR BROWN: Okay. We are recessed.
21 (Whereupon, the above-entitled matter went 22 off the record at 10:52 a.m. and resumed at 11:17 23 a.m.)
24 CHAIR BROWN: Okay. We're ready to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
62 reconvene. I think we are at the point of letting me 1
go through a few other -- well, before I do that, do 2
any of the other members have any other questions or 3
items they'd like to bring up? Before I launch into 4
one of my tirades, as Dennis so marvelously put it.
5 Hearing none, I will proceed on in.
6 If you look at your new DRG, and it's in 7
Section X.0.1.1, it's the third paragraph under Scope 8
of Review. The second sentence reads, well, I'll read 9
the first one. It says the type of application under 10 review largely determines the review activities to be 11 conducted and impacts the complexity and scope of the 12 review.
13 Then it goes on to say the scope and level 14 of detail for the I&C design should be the same for 15 operating
- licenses, combined
- licenses, and 16 manufacturing licenses, while less detail is an option 17 for design certifications, standard design approvals, 18 or construction permits.
19 And that's a change from the 6.2 review 20 version. It was made in response to an NEI 4.4-3. It 21 basically says that a new plant design certification, 22 that we've been doing for the last 12 years, the level 23 of detail does not have to be the same breadth or 24 depth that a replacement system in an operating plant 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
63 would require.
1 When you go through the DRG, there's 2
emphasis placed on detailed architecture, so that the 3
print meets all the fundamental principles, and that's 4
highlighted in a number of other sections, like 5
Section 0.2, 0.1.1, you know, 1.2, and on and on.
6 I
don't understand why design 7
certifications was moved out of the -- that whole 8
paragraph used to just read all six of those items in 9
a row, and then it was revised in this version to say, 10 to split them out, these three areas don't need 11 additional, they don't need the same level of detail 12 in their --
13 MEMBER BLEY: Charlie? This is Dennis.
14 CHAIR BROWN: Yes.
15 MEMBER BLEY: Can I jump in before the 16 staff answers you?
17 CHAIR BROWN: Yes. Go ahead.
18 MEMBER BLEY: Well, the one thing I liked 19 about this is in the first half, it says operating 20 licenses, combined licenses.
21 CHAIR BROWN: Yes.
22 MEMBER BLEY: It says, to me, that the I&C 23 review at the COLA stage has to be very thorough.
24 It's not cursory at all.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
64 CHAIR BROWN: That's correct.
1 MEMBER BLEY: Which is, I like having that 2
here. But go ahead.
3 CHAIR BROWN: That was there in the 4
version we did back in June, also. All of those 5
items, the whole list --
6 (Simultaneous speaking.)
7 MEMBER BLEY: -- here which means saying, 8
well, if your design cert isn't as complete as we'd 9
like, we're going to do a detailed review at the COLA 10 stage is what it says to me. And I like that.
11 CHAIR BROWN: Yes. But you know darn well 12 that when we do the design certification, it's 13 normally, we've had details. It used to -- that 14 whole, the thing that was added here was the while 15 less detail is an option for, instead of having the 16 whole string of six items.
17 And I can understand a thing like that 18 might not require having all the other details because 19 it's already done, theoretically. I guess you don't 20 have a construction permit until you've got a combined 21 operating license. Am I correct, or not? Do I get an 22 answer?
23 MR. ASHCRAFT: This is Joe Ashcraft. Ask 24 your question again. I'm sorry. I was trying to 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
65 formulate an answer for the overall context. Well, 1
we're going to take note of what you're saying, 2
Chairman, and I don't -- I can't recall whether this 3
was part of maybe OGC's resolutions or not. But we'll 4
look at it and we'll get an answer. But now back to 5
your last question. Could you repeat it?
6 CHAIR BROWN: Well, there was an NEI 4-3 7
resolution, apparently contributed to this. At least 8
that's the way I've got it noted here. I might be 9
wrong. But irrelevant. That's really irrelevant. I 10 just kind of fundamentally don't like having the less 11 detail for design certifications in there in the 12 standard design approvals because we've, we just did 13 a standard design.
14 There was just a standard design approval, 15 I guess, reviewed for NuScale, I guess. I've 16 forgotten who it was for. Is that right? My memory's 17 a little foggy.
18 MEMBER REMPE: Yes, that's correct 19 Charlie.
20 CHAIR BROWN: Okay, and I believe we had 21 hardly anything at all associated with that. So that 22 was considerably less design detail.
23 MEMBER REMPE: Charlie, it was consistent 24 with what was in the design certification, right?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
66 CHAIR BROWN: That's the theory.
1 MEMBER REMPE: I mean, that was -- it was 2
kind of, they didn't do anything different for the SDA 3
than they did for the design certification.
4 CHAIR BROWN: That was my understanding.
5 But we did not go through and have them -- they did 6
not go through a great level of discussion on that in 7
terms of everything. So anyway, that's my comment.
8 I'll pass that on to you. Hopefully --
9 MEMBER KIRCHNER: Charlie, this is Walt.
10 I'm with you on one point. Construction permit 11 harkens back to 10 C.F.R. 50, the old, the former two-12 step process. And there, of course at a construction 13 permit stage, you didn't have quite the final level of 14 detail that you would have for the others.
15 CHAIR BROWN: Yes.
16 MEMBER KIRCHNER: Like the operating 17 license stage.
18 CHAIR BROWN: Yes.
19 MEMBER KIRCHNER: Or as we've seen in the 20 combined license.
21 CHAIR BROWN: Yes. Just obviously, like 22 Diablo Canyon, when they replaced their stuff, or we 23 did the review for that, we had a very good 24 understanding of their architecture. That's an 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
67 operating plant. That's what I view as an operating 1
plant, an operating license, LAR type approach.
2 So anyway, that was the one comment. The 3
second one was --
4 MR. HOELLMAN: Hey Chairman Brown, do you 5
mind if I jump in for a second?
6 CHAIR BROWN: No.
7 MR. HOELLMAN: Just to sort of provide, I 8
guess, I think our reasoning for saying less detail is 9
an option for design certification is there's the 10 option for a design to use the Design Acceptance 11 Criteria, or DAC, in design certification. And so if 12 an applicant chooses to do that, then that's sort of 13 where we were going with allowing it as an option for 14 less detail.
15 CHAIR BROWN: Okay. Let me, just to 16 backtrack, I think, Dennis correct me, I remember we 17 went through a lot of pains with DAC on AP1000.
18 MEMBER BLEY: Just a couple things, 19 Charlie. We did, and we actually got an SRN from the 20 Commission at that point saying we'd be involved in 21 the later booking a DAC because of that. This is now 22 saying, to me, that it meets what we were trying to 23 get, if you got DAC, or DAC master rating as ITAC, 24 which we run into a little bit.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
68 The review at the COLA stage has to fill 1
in any gaps that were there. And it's not an 2
inspection, it's a review.
3 (Simultaneous speaking.)
4 MEMBER BLEY: -- we were after back then.
5 So that's why I thought this was a good separation.
6 We haven't always had all the details, but we've 7
always been able, the staff's always been able to 8
review at the level of the fundamental principles, 9
which is why they were developed in the first place.
10 CHAIR BROWN: Well, that doesn't happen on 11 ESBWR. There was virtually no information on the 12 initial --
13 (Simultaneous speaking.)
14 CHAIR BROWN: That was in 2008 in June, or 15 July, or August. Something like that.
16 MEMBER BLEY: But that's the history that 17 led to it.
18 CHAIR BROWN: Yes. That's why we started 19 this whole framework that led to making sure we had 20 detailed architecture with that. It took two years 21 before we had enough information. AP1000 was a lot 22 better, and we still had to wrestle with a few issues.
23 And then AP1400, or APR1400 and NuScale sailed through 24 because they recognized that's what we were looking 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
69 for, and we got very, very good DCDs and good 1
architecture presentations. So those were really 2
simple.
3 I'm just concerned that we're going to 4
lose what we've gained over the last 12 years in terms 5
of being able to make sure that we had a suitable 6
architecture for the plant.
7 MR. ASHCRAFT: Yes, Charlie. This is Joe 8
Ashcraft. We'll take note of that and get back to 9
you.
10 CHAIR BROWN: Okay. You'll get a copy of 11 my comment.
12 MR. ASHCRAFT: Okay. Good.
13 CHAIR BROWN: Okay. The second item was, 14 and I may have covered this if I can find it again.
15 It was in 01.2, Item 6, was where you introduced the 16 unidirectional communications. Oh, I think I covered 17 that. It ought to be covered in the actual appendix 18 also. I think I covered that one already.
19 MR. ASHCRAFT: Yes.
20 CHAIR BROWN: Okay. We'll go onto the 21 next one which was in Section 2.2.1.3, Review 22 Procedures, Item 8, and that is 2.2.1.3, that was 23 under diversity and defense-in-depth to address CCFs, 24 unless I've messed that up. No, Item 8, excuse me.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
70 Yes. Item 8.
1 MEMBER BLEY: Charlie, what was the number 2
again?
3 CHAIR BROWN: It was Section 2.2.1.3.
4 MEMBER BLEY: Three, okay.
5 CHAIR BROWN: That's diversity, defense-6 in-depth, I believe. And it's under the review 7
procedures. And it's line Item 8. There used to be, 8
in the initial version of this we reviewed, there are 9
now two new ones, Item 8 previously read provision of 10 a set of displays and controls located in the main 11 control room for manual system level actuation, et 12 cetera, et cetera.
13 And the revision deleted located in main 14 control. And that -- the reason was given, that was 15 an NEI comment 4-46, which stated that some advance 16 reactors may not have a traditional control room. And 17 therefore, they substituted the words controls 18 accessible to operators for manual system controls.
19 And I have -- accessible has no definition 20 and I'm not, you know, I was going to be proposing 21 that you modify that again and say retain the located 22 in the main control room. Yes. Revise located in the 23 main control room or accessible to operators in a 24 timely manner, based on a human factors engineering 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
71 analysis.
1 So you get your point, but we put some 2
meat on it. But we retain main control. I have a 3
hard time thinking no main control room. So deleting 4
all reference from main control room in this document 5
seems to be the wrong way to go, or not a good way to 6
go. So that's my comment. You'll get that also in 7
writing.
8 MR. ASHCRAFT: Noted.
9 CHAIR BROWN: Okay.
10 MEMBER KIRCHNER: Charlie?
11 CHAIR BROWN: Yes.
12 MEMBER KIRCHNER: This is Walt.
13 CHAIR BROWN: Yes.
14 MEMBER KIRCHNER: Unaccessible, as you 15 said, that needs -- it begs a definition. I'm doing 16 this from memory and I don't have the GDCs in front of 17 me but isn't it GDC 18 that requires protection for 18 the operators to conduct their business, essentially?
19 That, to me, is the accessible definition.
20 Some variation on that, whether it's in one of their 21 PDCs or it would seem to be, you have to provide for 22 protection of the operators.
23 CHAIR BROWN: Yes. I don't know all the 24 GDCs by heart. Not like some of you do.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
72 MEMBER KIRCHNER: Anyway, I'm just -- just 1
a pointer when thinking about what accessible means.
2 There is that GDC about habitability of the control 3
room. If there's no control room, it begs the 4
question where are these functions executed. But then 5
it would also beg the question, is that a habitable 6
accessible area?
7 Charlie suggested some words. We don't 8
want to rewrite this for them. But you know, 9
something like safely and easily accessible to the 10 operators might get that point across. But the staff 11 ought to be able to come up with something.
12 CHAIR BROWN: Yes, well I've given the 13 suggestion and let's see how they resolve it. I just 14 think you need a human factors evaluation of that 15 tossed into it. If you're going to make it 16 accessible, the only way you can kind of evaluate that 17 is, I agree with Walt, is to figure out somebody do an 18 analysis, and that it meets the accessible routine 19 based on somebody looking at some real human factors 20 considerations.
21 MR. ASHCRAFT: Yes. This is Joe Ashcraft.
22 So a lot of that, I'll just say, is from GDC 19, but 23 keep in mind, there's PDCs and I'd have to go back to 24 look at the wording to see how that modified it, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
73 potentially, or could modify it potentially.
1 But we note it, and --
2 CHAIR BROWN: Okay. That's all I'm trying 3
to do is get these to you so you can try to do what 4
you're going to do before the full committee meeting, 5
and let us know what you're going to do so we can 6
discuss it at the full committee meeting.
7 MR. ASHCRAFT: Understood. Thanks.
8 CHAIR BROWN: Thanks. I want the loose 9
ends to be able to be discussed at the full committee 10 meeting. That's why I'm bringing them up in this 11 detail.
12 MR. ASHCRAFT: Understood.
13 CHAIR BROWN: Then the next item was, I 14 think I've covered. You can confirm. It's 2.2.1.4.
15 That's predictable and repeatable behavior. And there 16 was a, in Appendix A, A-9, there's a sentence like 17 logic processing units are monitored by an independent 18 hardware based, the washed out timer comment that you 19 all put in in Appendix A-9.
20 MR. ASHCRAFT: Yes.
21 CHAIR BROWN: And I thought that should be 22 reflected as an additional item in the review 23 procedures listing in that 2.2.1.4. And you'll see 24 that in the comments I send.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
74 MR. ASHCRAFT: And that's where you're 1
talking about a pointer or something.
2 CHAIR BROWN: A what?
3 MR. ASHCRAFT: A pointer to that A-9.
4 CHAIR BROWN: You can do it that way also.
5 That's fine. I'm not, I don't object. We don't have 6
to just repeat stuff, but a pointer to A-9 would be 7
okay.
8 MR. ASHCRAFT: Understood.
9 CHAIR BROWN: As far as I'm concerned.
10 But it's a separate item.
11 MR. ASHCRAFT: Understood.
12 CHAIR BROWN: So the next one is in 13 Appendix A, Item A-8. It's in a lead in in Item 1.
14 Let me -- I got to go back and find that now.
15 MEMBER BLEY: Page 32, Charlie.
16 CHAIR BROWN: Well it depends on which 17 document you're looking at.
18 MEMBER BLEY: Within a page of 32.
19 CHAIR BROWN: Yes. Mine's on 33. It's 20 multi-unit stations. And this is the one I missed in 21 the 6/2, in our June 2nd subcommittee review. I had 22 reviewed, before that subcommittee, an earlier 23 revision of the DRG, an earlier version. I think it 24 was a March or April version.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
75 And then the N.0.0 version came down and 1
that modified that section, and I missed it. But an 2
earlier version, it stated -- which part is this.
3 Right at the beginning. Right now it says since SSCs 4
can be shared, the old version said while SSCs can be 5
shared among NPP units of multi-unit stations, the 6
reviewer should confirm that safety related systems 7
are not shared. Safety related I&C systems are not 8
shared among NPP units.
9 Okay, the new wording, since SSCs can be 10 shared, the reviewer should confirm, and the first 11 item says, safety related I&C SSCs are not shared 12 among NPP units unless it can be shown that such 13 sharing will not significantly impair their ability to 14 perform their safety functions, including in the event 15 of an accident in one unit, an orderly shutdown and 16 cool down of the remaining units.
17 And I'm trying to -- I don't like shared 18 stuff if you can -- well, I can't imagine a safety 19 system in Unit 1 being shared with eight other units, 20 or six other units, or whatever. All combined. In 21 other words, what does, what's the meaning of 22 significantly impaired? That means you can impair it 23 a little bit? Just one function. Two or three 24 functions are okay.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
76 Item 2, it's also then, if you look at 1
Item 2 in that listing, it says I&C design 2
descriptions in the application provide assurance that 3
safety related I&C SSCs are not share among units. So 4
the first item says they can be, as long as they don't 5
impair, and the second one says don't. So there's a 6
big inconsistency there, as well as just an 7
unsatisfactory approach in Item 1, in my opinion.
8 MR. ASHCRAFT: Understood.
9 CHAIR BROWN: I think we ought to, we 10 ought to be subject, you really ought to get rid of 11 this idea that you cannot significantly impair stuff.
12 That's the way I would -- it ought to just go back to 13 the way it read before. So that's that comment.
14 MEMBER BLEY: Well, let's -- there's a lot 15 of complications there and before the staff jumps on 16 what Charlie's suggesting, I'm wondering, have you 17 thought about this in more sorts of things. I could 18 imagine safety related electric power being shared 19 among modules in a multi-module system. I'm not sure 20 what else might be.
21 You know, we reviewed the design recently.
22 It's multi-modular. But because of uniqueness in 23 their design, the safety system -- and a limited 24 number of safety systems, they weren't shared because 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
77 they all fit kind of within each module package. So 1
I'm not sure, it makes sense to jump off and say they 2
can't be shared anywhere. Has the staff thought about 3
this in any detail?
4 CHAIR BROWN: These are I&C designs, not 5
the electric plans. This says I&C design, safety 6
related I&C SSCs, not electric plans. So I understand 7
your point, Dennis from that standpoint. Because I 8
thought we did have some shared systems on NuScale.
9 MEMBER BLEY: I'm not sure we had shared 10 safety systems. I have to go back and look more 11 carefully.
12 CHAIR BROWN: Oh, the I&C system --
13 (Simultaneous speaking.)
14 MEMBER BLEY: -- think about what kind of 15 I&C systems people may want to share and how they 16 define what's safety related. I don't know. I'd like 17 the staff to tell us a little bit about what led to 18 that and what kind of sharing their imagining would be 19 okay.
20 (Simultaneous speaking.)
21 MEMBER BLEY: Because off the top, I agree 22 with Charlie, but off the top is no way to do this 23 sort of thing.
24 MR. ASHCRAFT: Well if you, I guess we 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
78 pulled a lot of these words from appendix, I mean 10 1
C.F.R. part 50 Appendix A, Criteria 5, where it talks 2
about sharing of structure systems and components. So 3
I think that's sort of what brought us to these words.
4 But we'll take note of it.
5 MEMBER BLEY: At the full committee, maybe 6
you can tell us what you're thinking about it if you 7
decide to keep words like this. Because I haven't 8
thought about it in any detail 9
MR. ASHCRAFT: Right. Understood. Good 10 comments.
11 CHAIR BROWN: Normally when I think of 12 safety related I&C systems, I normally think reactor 13 trip and safeguard systems. Okay? There may be other 14 systems.
15 MEMBER BLEY: You know, it's kind of clear 16 there will be one for each unit, but there's other I&C 17 systems and I'm not sure exactly which ones are tagged 18 safety related and which ones aren't. And how they're 19 even tagged that way because if you're going to try to 20 be consistent with licensing modernization, that would 21 have an effect on that issue.
22 CHAIR BROWN: Well I always considered rod 23 control systems safety related I&C systems in my 24 plants. But in here, in the commercial world, they 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
79 are not safety related.
1 MEMBER BLEY: I guess at the full 2
committee meeting, I'd like to hear from the staff on 3
this one.
4 CHAIR BROWN: Oh, that's fine. That's the 5
purpose of bringing it up.
6 MR. ASHCRAFT: And your comment about this 7
is I&C, I mean, this Appendix A is a IEEE 603 8
criteria, which is not just specific to I&C. But 9
we'll take a look at the words and we'll provide 10 examples or, you know, have a discussion, or make 11 changes as necessary.
12 CHAIR BROWN: Well the second, Item 2, is 13 a direct, it's contradictory.
14 MR. ASHCRAFT: Yes. Understood.
15 CHAIR BROWN: Okay. So we've got to have 16 some resolution that doesn't have a conflict in it.
17 MR. ASHCRAFT: Understood.
18 CHAIR BROWN: Okay. And the last one, I 19 may have covered. That's the automatic and manual 20 control, that's A-9. And it was under manual control.
21 It was, oh, that was the diverse software based 22 digital equipment to perform coordinated actuation 23 logic.
24 And my recommendation would be, and you'll 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
80 see it in my comments, is to change the diverse 1
software to discrete hardware wired logic components, 2
which integrated circuit, you know, logic units that 3
are both fundamentally hardware. They are, they're 4
not microprocessors. You program them and that's 5
they're on and off, yes or no logic. The way we used 6
to build analog computers.
7 MR. ASHCRAFT: Understood.
8 CHAIR BROWN: So that's the last of my 9
miscellaneous comments. I fundamentally don't think 10 we ought to be, you know, introducing software back 11 into the manual actuation function, particularly when 12 it's going to be probably a single task after your 13 initial manual control.
14 And the priority and logics that were used 15 in
- NuScale, used hardware based logic
- units, 16 integrated circuits. So that was it for me. And 17 Christina will email this to you later in the week, 18 after I send it to her. Do any other members have any 19 additional comments?
20 Hearing none, I will -- Christina, can you 21 check to see if the phone line is open?
22 MS. ANTONESCU: Yes. Thomas, would you 23 please open the bridge line? Thomas, I'm sorry. You 24 said on?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
81 MR. DASHIELL: Yes. It is on.
1 MS. ANTONESCU: Thank you very much.
2 CHAIR BROWN: Okay. Thank you, Christina 3
and Thomas. Is there anyone on the bridge line, the 4
public line, that would like to make a comment? Is 5
NEI on that line, Christina?
6 MS. ANTONESCU: I believe so. Steve 7
Vaughn also is on the line.
8 CHAIR BROWN: Is he on a dedicated line?
9 MS. ANTONESCU: He's on the bridge line.
10 CHAIR BROWN: Oh, okay. Steve, are you 11 there?
12 MS. ANTONESCU: He was.
13 CHAIR BROWN: Okay. Is somebody back 14 again? I'm going to give it a few more seconds. I 15 heard a mute off come up. Is he still showing as a 16 participant, Christina?
17 MS. ANTONESCU: He's on the bridge line, 18 so he wouldn't show as a participant.
19 CHAIR BROWN: Oh, okay. Well mute is off.
20 So is anybody else on the bridge line that would like 21 to make a comment? Christina, am I back?
22 MS. ANTONESCU: Yes, you are.
23 CHAIR BROWN: Okay. My computer just put 24 me off. I just logged back in. Okay, well, I don't 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
82 hear anything on the bridge line. You can ask Thomas 1
to close the bridge line.
2 MR. DASHIELL: Closing the bridge line.
3 CHAIR BROWN: And if there is any more, or 4
one last round for the members. Does anybody else 5
like to make any additional comment?
6 MR. HECHT: Charlie, this is Myron.
7 CHAIR BROWN: Oh, yes.
8 MR. HECHT: I just wanted to let you know 9
that I actually was not able to respond here when you 10 asked at the beginning of the meeting.
11 CHAIR BROWN: Oh, okay.
12 MR. HECHT: Because I didn't press Star 6, 13 I just wanted to let you know that.
14 CHAIR BROWN: Okay. All right. Thank 15 you, Myron. Okay. With that, if there's no other 16 comments, we will adjourn the meeting. Staff, I 17 presume you will -- I will send these comments to you 18 and you'll be able to go through your resolution, 19 hopefully tell us what you plan to do before the 20 meeting so we can look at them.
21 MR. ASHCRAFT: Understood. Thank you ACRS 22 committee members for your
- comments, I
mean 23 observations. I'm sorry.
24 CHAIR BROWN: And thank you very much for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
83 the presentations today. I think we had some good 1
interchanges. I look forward to the full committee 2
meeting and we will be writing a letter unless my 3
members tell me that they don't want me to, which I 4
don't anticipate that, unfortunately. So the meeting 5
is now adjourned.
6 (Whereupon, the above-entitled matter went 7
off the record at 11:48 a.m.)
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.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
Design Review Guide (DRG):
Instrumentation and Controls for Non-Light Water Reactor (Non-LWR) Reviews Advisory Committee on Reactor Safeguards (ACRS) Subcommittee Meeting October 21, 2020 1
- Introduction
- Overview of instrumentation and controls (I&C) DRG to support the NRC staffs safety evaluation of advanced reactor applications
- Fundamental I&C Design Principles
- Overview of revisions to the DRG to address ACRS observations and public comments 2
Agenda
3 Licensing Modernization Project
- Licensing Basis Events
- Classification of Structures, Systems, and Components (SSCs)
- Defense-in-Depth (DID)
SSCs Including Radionuclide Barriers Safety Related (SR)
SSCs Non-Safety Related SSCs with Special Treatment (NSRST)
Non-safety Related SSCs with No Special Treatment (NST)
SSCs selected for required safety functions to mitigate DBEs within F-C Target*
SSCs performing risk significant functions SSCs performing functions required for defense-in-depth SSCs performing non-safety significant functions SSCs selected for required safety functions to prevent high consequence BDBEs from entering DBE region beyond F-C target Risk Significant SSCs Non-Risk Significant SSCs
- SR SSCs are relied on during DBAs to meet 10 CFR 50.34 dose limits using conservative assumptions
- NUREG-0800, SRP Chapter 7
- System-based approach for LWR licensing reviews
- Guidance not suitable for non-LWRs applications
- NuScale DSRS Chapter 7
- Improved safety-focused licensing review approach
- Improved licensing reviews efficiency and effectiveness
- Design Review Guide (DRG) for I&C
- Leverages the DSRS concepts
- Leverages lessons learned from recent new reactor I&C licensing reviews 4
Evolution of I&C Review Guidance
Goals 5
- Modernizes the I&C safety review in support of advanced non-LWR licensing applications
- Supports the NRCs vision and strategy for advanced reactor safety reviews
- Incorporates principles from Regulatory Guide (RG)-
1.233 Safety-focused Risk-informed Technology-Inclusive Performance-based
I&C System Review Framework 6
Overall Review Approach 7
Architecture
- The NRC staff review starts at the I&C architecture level
- Ensure that the information necessary to understand the proposed I&C architecture and system functions is available Safety-Significant Functions
- The NRC staff review focuses on safety-significant functions and selected SSCs that support them
- Ensure that the I&C performance objectives are met Functions Not Safety-Significant
- The design-related review for SSCs that the NRC staff determined are not safety-related and not risk significant should be less
- The NRC staff review focuses on ensuring that failure or operation of such SSCs will not prevent other SSCs from performing their safety-significant functions or adversely affect DID adequacy
8
- Control of Access,Section X.0.1.2, Item 6 The review should confirm that hardware characteristics that enforce unidirectional communication feature(s) (e.g., the use of a unidirectional/non-software based link that is connected only to a transmitter in the higher classified system and a receiver in the lower classified system) are considered by the applicant as the preferred means for mitigating any hazard(s) associated with communication paths.
9 Resolution of ACRS Observations
- Manual Controls, Appendix A, A.9 The manual controls provided in the I&C design should be connected downstream of the plants digital I&C safety system outputs. These connections should not compromise the integrity of interconnecting cables and interfaces between local electrical or electronic cabinets and the plants electromechanical equipment. The manual controls may be connected either to discrete hardwired components or to simple, dedicated, and diverse software-based digital equipment that performs the coordinated actuation logic.
10 Resolution of ACRS Observations
11 Resolution of Public Comments Example 1 Comment No. 4-7 The term fundamental I&C design principles is used throughout the document. It appears that these may be described in Section X.2.2.1. Is this intended as a definition?
Clarify where the definition of fundamental I&C design principles exists and explain the relationship between fundamental I&C design principles and PDCs.
12 Resolution of Public Comments Example 2 Comment No. 4-13 The guide states: The objectives of I&C system reviews are to confirm that: (1) the I&C system design includes the functions necessary to assure adequate safety during operation of a NPP under normal operation, transient, and accident conditions; The statement refers to functions in the context of a finding of adequate safety. The statement is not specific as to the type of functions that are part of an adequate protection finding.
In the NEI 18-04 context, fundamental safety functions are those that are important to a finding of adequate protection. Recommend rewording item (1) as follows:
(1) the I&C system design addresses the fundamental safety functions as stated in Proposal for a TechnologyNeutral Safety Approach for New Reactor Designs, Technical Report IAEA-TECDOC1570, to assure adequate safety during operation of a NPP under normal operation, transient, and accident conditions;
Schedule Milestones 13 Activity Completion Date A.1 Addressing public/ACRS comments COMPLETE A.2 2nd DRG ACRS Sub-Committee meeting October 21, 2020 A.3 DRG ACRS Full Committee meeting December 2020 A.4 Incorporate ACRS recommendations and prepare final DRG 1st Quarter 2021
14
ARCAP - advanced reactor content of application project CCFs - common cause failures CFR - Code of Federal Regulations DG - draft regulatory guide DID - defense-in-depth DRG - Design Review Guide DSRS - design-specific review standard I&C - instrumentation and controls IEEE - Institute for Electrical and Electronics Engineering LBE - licensing basis event LMP - licensing modernization project LWR - light water reactor NEI - Nuclear Energy Institute non-LWR - non-light water reactor NMSS - Office of Nuclear Material Safety and Safeguards NRR - Office of Nuclear Reactor Regulation NSIR - Office of Nuclear Security and Incident Response OGC - Office of the General Counsel PDC - principal design criteria RES - Office of Nuclear Regulatory Research RG - Regulatory Guide SMR - small modular reactor SRM - staff requirements memorandum SSCs - structures, systems, and components Std - standard TICAP - technology-inclusive content of application project 15 Acronyms
16 Backup Slides
17 Core Review Team Approach
- Non-LWR Review Strategy - successfully implementing for non-LWR preapplication reviews
- Multi-disciplinary core review team supported by subject matter experts from NRR, NMSS, NSIR, RES, OGC
- Focus on the Fundamental Safety Functions
- Perform an Integrated System Design Review
- Demonstrate Compliance with Applicable Regulations
I&C Safety-Focused Review Initiative 18
- Additional lessons learned and new opportunities
- New initiative started
- Create new, improved guidance for future design reviews in a timely manner
- Building on DSRS
- Close coordination
- Advanced reactors
- I&C modernization
- Innovation and transformation at the NRC DSRS Design Review Guide (DRG)
19 Control of Access (Appendix A, Section A.6)