ML25134A252
| ML25134A252 | |
| Person / Time | |
|---|---|
| Issue date: | 04/17/2025 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| NRc-0277 | |
| Download: ML25134A252 (1) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Plant Operations and License Renewal Docket Number:
(n/a)
Location:
Hampton, New Hampshire Date:
Thursday, April 17, 2025 Work Order No.:
NRC-0277 Pages 1-99 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1716 14th Street, N.W.
Washington, D.C. 20009 (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 PLANT OPERATIONS SUBCOMMITTEE 7
+ + + + +
8 THURSDAY, APRIL 17, 2025 9
+ + + + +
10 The Subcommittee met at the Best Western 11 Plus The Inn at Hampton, 815 Lafayette Road, Hampton, 12 New Hampshire, at 2:00 p.m., Gregory H. Halnon, Chair, 13 presiding.
14 COMMITTEE MEMBERS:
15 GREGORY H. HALNON, Subcommittee Chair 16 WALTER L. KIRCHNER, ACRS Chair 17 DAVID A. PETTI, Member-at-Large 18 RONALD G. BALLINGER 19 VICKI M. BIER 20 VESNA B. DIMITRIJEVIC*
21 CRAIG D. HARRINGTON 22 ROBERT P. MARTIN 23 SCOTT P. PALMTAG 24 THOMAS E. ROBERTS 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
2 ACRS CONSULTANTS:
1 DENNIS BLEY 2
STEPHEN SCHULTZ*
3 4
DESIGNATED FEDERAL OFFICIAL:
5 QUYNH NGUYEN 6
7 ALSO PRESENT:
8 LARRY BURKHART, Branch Chief, ACRS, NRC 9
TRAVIS DAUN, Region I, NRC 10 NIKLAS FLOYD, Region I, NRC 11 NATE MENTZER, Region I, NRC 12 13 14 15 16 17 18 19
- Present via teleconference 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
3 CONTENTS 1
Call to Order and Opening Remarks........
5 2
ACRS Overview and Purpose of Meeting
...... 11 3
Seabrook Visit 4
Region I: Reactor Oversight........... 21 5
ACRS Wrap-Up
.................. 66 6
Public Comments................. 92 7
Closing Remarks................. 99 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 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
4 P-R-O-C-E-E-D-I-N-G-S 1
2:00 p.m.
2 CHAIR HALNON: Good afternoon. I'm Greg 3
Halnon, Chair of the Plant Operations and License 4
Renewal Subcommittee of the Advisory Committee on 5
Reactor Safeguards.
6 ACRS members in attendance in person are 7
myself, Tom Roberts, Dr. Ron Ballinger, Dr. Robert 8
Martin, Dr. Scott Palmtag, Dr. Dave Petti, Dr. Craig 9
Harrington, Dr. Walt Kirchner, Dr. Vicki Bier. I do 10 expect that Dr. Vesna Dimitrijevic will be online.
11 We also have with us our consultant, Dr.
12 Dennis Bley, and online is Dr. Stephen Schultz.
13 If I missed anybody, either ACRS members 14 or consultants, please speak up.
15 Okay. Dr. Quynh Nguyen of the ACRS staff 16 is our Designated Federal Officer for this 17 Subcommittee meeting.
18 And we do have a quorum for today's 19 meeting.
20 The ACRS was established by statute and is 21 governed by the Federal Advisory Committee Act, or 22 FACA. The NRC implements FACA in accordance with our 23 regulations. I will go into more detail about the 24 Committee in just a few minutes. Per these 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
5 regulations and the Committee's bylaws, the ACRS 1
speaks only through its published Letter Reports. All 2
members' comments should be regarded as only the 3
individual opinion of that member, not a Committee 4
position.
5 All relevant information related to the 6
ACRS activities, such as letters, rules for meeting 7
participation, and transcripts are located on the NRC 8
public website and can be easily found by typing 9
"About us ACRS" in the search field on the NRC's home 10 page.
11 The ACRS, consistent with the agency's 12 values of public transparency in regulation of nuclear 13 facilities, provides opportunity for public input and 14 comment during our proceedings.
15 We have received written comments from the 16 C-10 organization and they have requested, also, time 17 to make some oral comments prior to the conclusion of 18 the meeting. Now, this does not preclude other 19 members of the public from making comments. So, we 20 will open up that portion of the meeting for all, and 21 we welcome all your thoughts.
22 Additional written statements may be 23 forwarded to today's Designated Federal Officer, as I 24 mentioned, Quynh Nguyen. We also will set aside time 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
6 at the end of this meeting for public comments, as I 1
mentioned.
2 A transcript of the meeting is being kept 3
and will be posted on our website.
4 Now, in the room we have name tags. As 5
you can see, the court reporter here can see who is 6
talking. If you do not have a name tag and you do say 7
something that you want on the record, the court 8
reporter will need to know who you are and your 9
affiliation, as appropriate, so that the record will 10 be accurate on who to credit the statement to.
11 Each table has microphones for the members 12 and staff who desire to speak. And I believe you guys 13 are familiar with that one. I've coached these folks.
14 We know what to do.
15 For the public portion, we will have a 16 microphone at the stand. And Andrea Cass -- where is 17 Andrea? Okay. Thank you, Andrea. If there's 18 multiple people that would like to make a statement, 19 she will make sure that it's orderly up to the 20 microphone. Only comments made into that microphone 21 will be on the record.
22 The Teams chat feature is going to be 23 unavailable during this meeting, but the meeting is 24 being transmitted over Teams. And again, only things 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
7 that go through the microphone will get provided to 1
Teams.
2 But if somebody is talking and you make a 3
comment nearby, I can't guarantee that that won't be 4
online. So, be careful in any kind of side 5
conversations. It would be really nice if you just 6
limited those to only what was necessary.
7 And I would also ask everybody to maintain 8
a professional and courteous decorum throughout this 9
afternoon.
10 Finally, if you have any feedback for the 11 ACRS about today's meeting, we encourage you to fill 12 out the public meeting feedback form, which is also on 13 the NRC website.
14 During today's meeting, the Committee will 15 consider the topic of alkali-silica reaction, or ASR, 16 at the Seabrook Nuclear Station. Today, the members 17 visited Seabrook to observe NextEra's Aging Management 18 Program and interact with the staff managing the 19 issue.
20 Region I staff, with the consultation of 21 NRC headquarter experts, provides inspections and 22 oversight of all plant operations, including the 23 management of ASR.
24 In a few minutes, we'll hear a synopsis of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
8 the issues, along with recent oversight information 1
and what is expected in the upcoming future cycle of 2
the inspections from our Region I staff.
3 The agenda for this afternoon consists of 4
myself going over some brief remarks about the ACRS, 5
and then, we'll touch briefly on what we saw this 6
morning at the plant.
7 We will walk through the history of the 8
ACRS with ASR, and then, we're going to ask Region I 9
staff to provide the information from their 10 perspective on the issue.
11 The Committee will hold some discussions 12 amongst the members, and then, ask the public to 13 provide comments on the record.
14 I want to emphasize a few items.
15 We ask that the public limit their 16 comments to two to three minutes.
17 When called upon, proceed to the aisle 18 microphone, state your name and, if appropriate, your 19 affiliation, and make your comment.
20 At this type of forum, the Committee will 21 not engage in a Q&A or a question-and-answering 22 session. However, if you do have a question that you 23 want to get answered, we ask that you write it down 24 and send it to Dr. Quynh Nguyen, as previously 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
9 mentioned. His email address will be on the meeting 1
notice.
2 The Committee members will then take all 3
your comments, in addition to the information that we 4
have gained today, into consideration as we continue 5
to engage in this topic during our May full Committee 6
meeting, where we will take up this topic for further 7
deliberations.
8 I wanted to make sure that, from Larry's 9
perspective, who is our Branch Chief, did I miss 10 anything? We're good? Okay.
11 So, this portion I wanted to walk through, 12 and this is mainly for you all out there. What is the 13 ACRS and what do we do? It's not all that usual that 14 the ACRS will visit a plant and walk through an issue 15 like this. So, I wanted to make sure you know why we 16 are here.
17 Let's go to the next slide.
18 First of all, I want to introduce you to 19 the members.
20 We have Dr. Ron Ballinger and Dr. Craig 21 Harrington, our material experts.
22 Dr. Scott Palmtag and Tom Roberts here are 23 kind of looking at the organization and how the 24 management of the program came across.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
10 We have Dr. Walt Kirchner back here, who 1
is the Chairman of the ACRS Committee, and Dr. David 2
Petti, who is our member of leadership on the 3
Committee, member-at-large.
4 Dr. Bob Martin, Dr. Vicki Bier, and our 5
consultant Dr. Dennis Bley.
6 A lot of experience both in the industry 7
and labs and Navy, and that list is way too long.
8 I'm going to go through the ACRS's further 9
introduction on what we do. We'll have Region I come 10 in, and then, we're going to talk about what we saw 11 this morning at the site.
12 Go ahead to the next one.
13 The ACRS purpose, if you didn't know, the 14 NRC has just recently redone their mission statement.
15 "The NRC protects public health and safety and 16 advances the Nation's common defense and security by 17 enabling the safe and secure use and deployment of 18 civilian nuclear energy, technologies, and radioactive 19 materials through efficient and reliable licensing, 20 oversight, and regulation for the benefit of society 21 and the environment." That was just redone in January 22 2025.
23 The ACRS is 100 percent independent from 24 the rest of the staff, and we want to complement and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
11 make sure that that mission statement is fulfilled.
1 Let's go to the next slide.
2 We have a long history all the way back 3
from, if you look at where nuclear started, for some 4
of you historians, the Chicago Critical Pile. That 5
was where the first, if you will, fission took place 6
in our nuclear energy.
7 We were established as the NRC in the mid-8 70s. And now, of course, you've heard a lot about the 9
ADVANCE Act, about advancing nuclear energy through 10 this system.
11 The ACRS has been involved all the way 12 from just after that Chicago Critical Pile. So, the 13 ACRS has been a longstanding organization and has had 14 a lot of history on technical issues.
15 Let's go to the next one.
16 We operate by FACA, as I mentioned, which 17 talks about the openness and candor. We are not bound 18 in our discussions by any regulations, rules, or 19 anything. We can ask anything that we think needs to 20 be asked.
21 We also want to be completely transparent.
22 Everything we do is on our website. All of our 23 meetings are public, unless there's some proprietary 24 information that goes through.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
12 Our deliberations are conducted in public, 1
and then, of course, I mentioned that our Letter 2
Reports and Memorandums are all publicly available.
3 We independently review and we report to 4
the Commission directly. We look at safety studies, 5
reactor facility operations, license applications. We 6
advise the Commission on hazards for proposed and 7
existing nuclear reactors, which is one of the reasons 8
why we're here today. And we independently review and 9
advise matters referred to it by the Commission. So, 10 the Commission may be concerned about something and 11 they would tell us to take a review of that item.
12 Those last two -- I grayed-out some of the 13 other ones, so that you didn't have to worry about 14 those. They're not necessarily as relevant.
15 As I mentioned, we are independent. We 16 have up to 15 members. What do we have now, 12?
17 Eleven members now. And we try to keep the mix of 18 experience across the board. Some of us are 19 operators; some of us are safety analysis people; some 20 are materials, as I mentioned. We have fuel experts, 21 methods experts, all kinds of stuff.
22 We do use some consultants to do 23 assessment reviews. This is why Dr. Bley is here.
24 And like I mentioned, we try to maintain a very broad 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
13 level experience across the board.
1 We have a subcommittee structure. This is 2
online. We've got all of our Subcommittees on the 3
left; we've got the names on the right.
4 If you go to the next one, I'll just give 5
you an example. This is where I'm responsible for.
6 You see the Plant Operations Subcommittee over here on 7
the second-to-the-bottom one. I'm also on the 8
Regulatory, Rulemaking, Policies. So, these are our 9
focus areas. These are the ones that we stay involved 10 in. You can see I'm Chair of the Operations 11 Subcommittee and that's another reason why we're here, 12 is because I follow the existing reactor fleet and 13 their performance.
14 The review process.
15 I see people squinting. These slides are 16 all available on the website.
17 We have all kinds of inputs, and our 18 outputs are, like I mentioned, Letter Reports. We 19 sometimes do some white papers. We have meeting 20 summaries. Every meeting has a summary written up on 21 it to discuss what we did. Of course, we have the 22 transcripts as well.
23 And then, we also provide -- one of the 24 most valuable things, other than the Letter Report 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
14 conclusions, is that we have technical discussions 1
that we kick around topics where the Committee has 2
some experience and we engage with both the staff and 3
licensees who come in for presentations. And we kick 4
around these issues and there's a lot of experience 5
and a lot of wisdom, both given to them and we learn 6
as well. Because a lot of the licensees have 7
tremendous experience behind them, as well as our 8
staff.
9 We do subcommittees, like we're doing 10 here. We do presentations. This Subcommittee, the 11 main purpose is to gather information, so that we can 12 take it to the full Committee and have official 13 deliberations in the public eye of the topic. And 14 that's what we're doing here today. We came to gather 15 information and to provide ourselves with a good 16 collegial discussion coming up in May. And that's why 17 we enjoy the public comments, because that's part of 18 us getting information.
19 Again, as I mentioned -- I can't emphasize 20 this too much -- since we do a lot of talking, we only 21 conclude our official position through the Letter 22 Reports to the Commission or the Executive Director of 23 Operations.
24 Again, I'm trying to circle the relevant 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
15 pieces, the operation, looking at the reactor safety 1
oversight. We look at significant events, generic 2
issues, and our reactor oversight process. And again, 3
that's one of the reasons why we're here today, 4
because it's part of our responsibilities.
5 We've always been attentive to 6
improvements in nuclear power plants. This picture is 7
we visited the Abilene Christian University. They're 8
building a molten salt reactor. So, we went and 9
visited that two years ago.
10 And we, again, gather that information, so 11 that we can input that into all parts of our reviews.
12 We learned a lot about instrumentation there. We 13 learned a lot about molten salt. Some of that, 14 obviously, applies to the advanced reactors coming 15 down the pike, but it also gives us experience for 16 looking at the reactor oversight process and how we 17 monitor our own plants that are running right now.
18 So, in summary, the Plant Operations 19 Subcommittee, we're monitoring the industry. We do 20 that on a routine basis. We are looking at operating 21 experience, all the inspection reports. We look at 22 events that may occur.
23 We bring those significant issues before 24 the Committee and we look at the changing regulatory 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
16 landscape with the ADVANCE Act and the changes to the 1
reactor oversight process, but we do try to keep our 2
focus on safety-significant issues, things that our 3
limited time can best help the safety of the industry, 4
and provide that advice to the Commission and the 5
Executive Director of Operations.
6 Again, we want to make timely advice to 7
the Commissioners. So that, in their implementation 8
of the mission, that we can make sure that they are 9
fully informed.
10 Okay. With that, I'm going to ask Dr.
11 Bley just to give a quick walkthrough of the ASR issue 12 and how it has progressed through the ACRS Committee, 13 and then, we'll turn it over to Region I.
14 DR. BLEY: Thanks, Greg.
15 The beginnings of this go back 16 years.
16 In 2009, NextEra identified pattern cracking in 17 sections of walls and some other structures. A year 18 later, they were able to confirm that the cracking was 19 due to ASR. And that's the first time that's cropped 20 up in this industry.
21 A
year after
- that, NRC issued an 22 Information Notice to alert all the other plants that 23 there was a plant with an ASR problem.
24 And the year after that, three years since 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
17 the beginning, our Seabrook License Renewal 1
Subcommittee met in July of 2012. None of the members 2
attending that meeting are still on the Committee. I 3
was a member, but there were other things going on and 4
I wasn't there.
5 We heard from the staff that they still 6
had many questions. This was Seabrook had come in and 7
were looking for license renewal. And ASR, as they 8
began to understand it more, the NRC had many 9
questions and learned things that day for the first 10 time and said they would really need to come back to 11 the Committee for a second meeting. That wouldn't 12 happen for about six years because of a variety of 13 reasons.
14 In 2014, two years later, we had an 15 information briefing with the staff and their 16 contractors at the time, not just on ASR, but on all 17 concrete degradation issues. About half of the 18 meeting was on everything else and half on ASR.
19 It was pretty much a
theoretical 20 discussion and discussion of plant experiments. And 21 the staff indicated they would perform confirmatory 22
- research, but not exploratory or anticipatory 23 research.
24 One of the presenters reminded us that, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
18 for a structure to behave in a fully composite 1
fashion, the rebar and cement had to be completely 2
bonded and noted that some studies on ASR had shown 3
there could be some, quote, "very funny things 4
happening" -- I think that's chemistry -- around the 5
rebar that could significantly reduce bond strength.
6 And I think that's some of what led to the extensive 7
experiments to see if that could be a problem for this 8
plant.
9 We also learned that NIST was doing some 10 experiments and a group of universities were also 11 involved in experiments and in trying to develop a 12 large computer model of all forms of concrete 13 degradation.
14 And when pressed -- not pressed hard; just 15 asked -- "Can you really believe a model that 16 complex?" the professor from Vanderbilt noted that, 17 "No, we can't," but we can use them and the follow-on 18 experiments, the testing and aging management 19 programs, to track the process and see if we're 20 modeling it correctly.
21 There were several things that went on 22 over the next few years, including the ACRS visited 23 NIST and observed the test setups. Also, two of our 24 members went to the University of Texas and looked at 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
19 their test arrangement.
1 And in 2015, we learned that NRC Resident 2
Inspectors had observed degraded fire seals and 3
changes in seismic gaps caused by differential 4
building movement, leading to further work on ASR and 5
a new Aging Management Program.
6 In October of 2018, we had the ACRS 7
meeting on license renewal, and many of the members 8
who attended that session and participated are still 9
on the Committee.
10 ASR imposes -- well, you'll hear more 11 about ASR -- structural issues that need to be 12 addressed. And the license application had two 13 requests -- I'm sorry -- LARs and two NRC safety 14 evaluations, one for license renewal and one for the 15 current license.
16 In December of 2018, the Committee wrote 17 a letter endorsing what the staff had presented in 18 their SE, that both NextEra and the NRC staff 19 considered the issue closed with the long-term Aging 20 Management Programs involved. The Committee agreed 21 with that, identifying that it was important that that 22 work be done forever, I think.
23 In 2021, NRC received a letter from two 24 Senators, Markey and Warren, that requested ACRS 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
20 continue to follow the issues.
1 And in April of 2022, there was a joint 2
ACRS Subcommittee meeting, three of the Subcommittees, 3
and now, most of the members at that meeting are also 4
here with you.
5 And the work continues. Greg told you why 6
the Committee came here now, to see how the process 7
for controlling ASR has been carried out.
8 CHAIR HALNON: Thank you, Dennis.
9 At this point, we'll turn it over to --
10 Travis, are you up? Or Nik or Nate?
11 MR. MENTZER: Nate, yes. Thank you.
12 All right. Good afternoon, Members of the 13 ACRS, and welcome to Seabrook.
14 My name is Nate Mentzer. I'm a Senior 15 Project Engineer in Region I, and with me today are 16 two more familiar faces, Travis Daun, the Senior 17 Resident Inspector at Seabrook, and Nik Floyd, the 18 Senior Reactor Inspection in Region I.
19 For our presentation today, we'll go 20 through an assessment summary, our NRC assessment 21 summary to date. We will do a quick refresher on ASR, 22 the background and history of that; focus heavily on 23 Seabrook's aging management and Aging Management 24 Programs for ASR, and then, we'll discuss the NRC 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
21 inspection, oversight, and assessment on
- ASR, 1
primarily in the last five years, but we also met in 2
September of 2024 and presented the information then.
3 And so, an update since then, and then, a final, next 4
steps.
5 From there, I'll turn it over to Travis.
6 MR. DAUN: All right. Thanks, Nate.
7 For the first slide, we thought it was 8
important to provide our overall assessment of the ASR 9
issue at Seabrook. So, as you can see from the slide, 10 we determined Seabrook's structures remain capable of 11 performing their safety functions as intended, and 12 that's under all limiting conditions.
13 We will continue to verify NextEra's 14 performance to monitor and take corrective actions to 15 maintain their structures, and we will continue to 16 verify NextEra's performance to meet ASR-related 17 License Conditions.
18 So, what does that really mean? So, we 19 continue to inspect ASR closely at Seabrook, probably 20 closer than a lot of the other baseline inspection 21 programs that we do.
22 As the Senior Resident Inspector, my 23 Resident, Seamus Flanagan, who is sitting right behind 24 me, we remain cognizant of all the ASR degradation 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
22 mechanisms at the site. All right. We're very 1
familiar with the areas that they see ASR impacts, 2
building deformation, and equipment impacts as a 3
result of building deformation.
4 I also talk to all of the inspection team 5
leads for any of the team inspections that come on the 6
site; make them aware of the ASR issues at Seabrook 7
and how they can incorporate those into their 8
inspection. And I think Nik will talk a little bit 9
about it somewhere.
10 It's not only mine and Seamus' inspections 11 that identify ASR-related issues. It's not only Nik's 12 inspections that identify those things, but there's 13 other inspection teams that have incorporated that 14 background into their inspection and have identified 15 things.
16 So, it gets communicated that way, and 17
- then, inspections such as the aging-related 18 degradations inspection, the biannual PI&R 19 inspections, and then, other baseline inspections.
20 So, go now to the next slide.
21 CHAIR HALNON: So, Travis, as you go, 22 since you opened the door on continuing to verify, 23 from an inspection hours perspective --
24 MR. DAUN: Yes?
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23 CHAIR HALNON: -- the ROP's roughly 2,000 1
hours a year, correct? It's 1600. I think it's 16 --
2 depending on where you are in the oversight process.
3 MR. DAUN: I haven't thought about the 4
number of hours.
5 CHAIR HALNON: Take my word for it, 1600 6
hours a year to 1800.
7 Since you didn't have that number in your 8
mind, I'm not going to ask you for a percentage of 9
time. But from your perspective, in a month's 10 timeframe, how much of that time do you think is 11 dedicated to ASR?
12 MR. DAUN: Dedicated to ASR? So, I would 13 probably tell you more from an annual. So, weekly, we 14 are going through the Corrective Action Program daily, 15 right? Seamus and myself are both reading every 16 corrective action request, every action request that's 17 in their system daily.
18 If there is something that relates to ASR, 19 such as, you know, a fire seal that seems to have 20 shifted, they're doing walkdowns. I would guess, from 21 a CR perspective, there's about 50 a year directly 22 related to ASR, right? And those, we package up, 23 review. We'll talk to Nik Floyd, see if there's 24 anything immediately we have to do there. A lot of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
24 times, if it's a seal or something like that, we will 1
walk it down usually that day to take a look and make 2
an assessment.
3 Outside of that, then incorporating into 4
your other baseline inspections. So, things such as 5
internal flooding samples, it comes into play. Things 6
like equipment walkdowns, we're always cognizant of, 7
you know, structural supports for piping. So, we're 8
looking at those, understanding that there are 9
buildings moving. So, it's incorporated into almost 10 every one of those inspections.
11 The fire protection inspections, we're 12 looking at fire seals. And a lot of times, you'll see 13 fire seals between buildings. That's where you'll see 14 separation there. So, we incorporate that into those 15 samples.
16 So, while there aren't direct ASR samples, 17 which I'll talk about in a second, outside our routine 18 baseline inspections, I would guess 80 percent of them 19 have some component that we're looking at ASR as an 20 aspect and if it can impact that sample.
21 Then, for annual PR&I samples, Nik Floyd 22 comes out and does samples on what's in their 23 Corrective Action Program; what actions they've taken, 24 and then, for operability, they have a lot of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
25 structures that are in their prompt operability 1
determination space. Nik takes a look at those 2
routinely. So, his samples, I think they're usually 3
in a year probably about 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> between you and 4
your team to do those, and then, the ancillary that we 5
put into every sample.
6 CHAIR HALNON: Okay. So, it sounds like 7
it's fair to say -- and stop me if it's not -- that, 8
at least from an oversight perspective, daily you're 9
talking about ASR?
10 MR. DAUN: I would say we are thinking 11 about ASR --
12 CHAIR HALNON: Or at least it's in the 13 conversation?
14 MR. DAUN: -- daily. We may not have a 15 conversation with Nik daily. Seamus and I may not 16 have a conversation --
17 CHAIR HALNON: Okay.
18 MR. DAUN: -- unless there's -- there are 19 days where, "Hey, did you see the CR? Do we know what 20 that means?" There are days that we have that 21 conversation, but I can't say it's every day that we 22 have a conversation on it.
23 CHAIR HALNON: Okay, but you observe the 24 licensing meetings?
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26 MR. DAUN: Correct.
1 CHAIR HALNON: Are they talking about it 2
every day?
3 MR. DAUN: I can't say they're always 4
talking about ASR every day. That's the only time --
5 CHAIR HALNON: Okay, but you hear it 6
often?
7 MR. DAUN: We try to be careful --
8 CHAIR HALNON: You hear it often, though?
9 MR. DAUN: We hear it often.
10 CHAIR HALNON: Okay. And then, from what 11 we heard this morning, there's at least a daily 12 meeting where they're talking specifically ASR with 13 the fleet.
14 MR. DAUN: Okay. Yes.
15 CHAIR HALNON: If you sat in those 16 meetings, you would have said, "Yes, they talk about 17 it daily."?
18 MR. DAUN: Right, if we sat in those 19 meetings. We don't, typically, sit in the --
20 CHAIR HALNON: Project meetings?
21 MR. DAUN: You know, they're daily work 22 management, you know, before they're sending people 23 out. We attend other meetings. We attend station, 24 overall station plan meetings. We do review the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
27 schedules. We do know the ASR work that's going on at 1
the site, but we don't sit in their daily ASR 2
meetings --
3 CHAIR HALNON: Okay.
4 MR. DAUN: -- just as we don't sit in 5
always their daily -- you know, every shop has a daily 6
meeting and we don't sit in meetings all day long. We 7
like to spend some time in the field.
8 CHAIR HALNON: Okay. I get that.
9 In this progression of findings that 10 occurred over the last four years or five years or so, 11 have you seen, have you grown -- you've been there for 12 what? How many years?
13 MR. DAUN: Six years.
14 CHAIR HALNON: So, you've been there 15 through this whole session. Have you seen a growing 16 level of yourself being more confident the site is at 17 least "all over this," I guess is the colloquial 18 language to use. Are they all over this?
19 MR. DAUN: I would say, you know, yes, 20 from the NRC office, from our Resident office, yes, I 21 think we are much more cognizant today than we were 22 six years ago. I would say that, six years ago, they 23 were more cognizant of it than they were six years 24 before that.
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28 CHAIR HALNON: Okay. So, it's grown?
1 MR. DAUN: It is a growing knowledge base 2
within the Resident office. We have always thought 3
about ASR, and as we develop more skills in it, I feel 4
very comfortable with all the mechanisms at this 5
point. When I first got here six years ago, I wasn't 6
as confident. It was a new, relatively new thing.
7 CHAIR HALNON: Okay. That helps.
8 MR. DAUN: For the licensee, yes, I think 9
it is much more on the forefront of their discussions, 10 especially looking at CRs. Before, you may have a CR 11 that talked about a fire seal that delaminated and it 12 wasn't tagged to ASR. It was tagged to the 13 maintenance group to go out there and inspect it and 14 repair as needed. But it wasn't necessarily getting 15 pulled into their ASR program.
16 They are much more likely today than they 17 were six years ago to flag those things and say, yes, 18 we also need to send this to the ASR group to evaluate 19 why did the seal delaminate. Maybe it had nothing to 20 do with ASR or maybe it did. And especially their 21 onsite engineering teams are much more cognizant of 22 that than I think they were when I first got here.
23 CHAIR HALNON: And that's sort of what I 24 wanted to explore, was the findings not only fix the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
29 issues specific to the findings, but it sounds like it 1
also tuned up both organizations on this issue to be 2
more diligent and cognizant of what's going on in --
3 MR. DAUN: One hundred percent.
4 CHAIR HALNON: Okay. Thank you.
5 MR. DAUN: Okay. Next slide.
6 We'll run through a quick background in 7
the ASR, which is on the lefthand side of this slide, 8
just to recap what is an ASR and what are we actually 9
talking about.
10 So, concrete consists of three main 11 ingredients. You have coarse aggregate, which are the 12 rocks such as gravel; you have fine aggregate, and 13 then, the cement that binds them together.
14 So, the aggregate that is actually the 15 cause of ASR at Seabrook is this coarse aggregate.
16 And ASR is a chemical reaction that occurs within the 17 concrete. So, you have reactive silicon present in 18 the aggregate. It reacts with the hydroxyl ions and 19 alkali ions in the cement, and then, it produces an 20 alkali-silica gel. So, this gel is what actually 21 expands as it absorbs water, and that expansion within 22 the concrete is what's placing stresses on the 23 structures.
24 Again, in order for the reaction to occur, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
30 you need all three conditions. You need radioactive 1
aggregate -- or radioactive? Sorry -- reactive 2
aggregate, yes, reactive aggregate. You need high 3
alkalized cement pour solution, and then, you need 4
adequate moisture, typically, humidity levels above 80 5
percent.
6 And then, ASR, the only way to confirm ASR 7
is through petrographic analysis, which requires a 8
core bore to be taken out of the concrete, polished, 9
but down, and then, looked at for petrographic 10 analysis.
11 So now, looking at the background, I don't 12 want to recap the entire background that you just 13 provided, but I'll hit the things that maybe weren't.
14 So, right in 2009, in preparation for 15 their license renewal, they identified aggressiveness 16 with the groundwater at the site that was in contact 17 with their concrete structures. They performed 18 testing again in August 2010, which confirmed they did 19 have ASR.
20 Because they had ASR -- their original 21 code of record did not assume ASR -- so, at that 22 point, they were outside their licensing basis and 23 they entered into a prompt operability determination 24 process to determine that the structures were still 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
31 adequate and able to meet their safety functions.
1 They assumed that the original cement and 2
aggregate was not susceptible to ASR, right. The ASTM 3
test methods at the time of the pours at Seabrook were 4
good at detecting fast-reacting aggregate, but not the 5
slow-reacting aggregate that they got. So, ASTM test 6
methods, just for awareness, nowadays would detect 7
that slower-reacting aggregate.
8 To resolve the open operability 9
determination related to ASR, they chose to perform a 10 large-scale test program at the University of Texas, 11 Austin, from 2013 to 2016, to better understand ASR's 12 impact on the structural performance; basically, the 13 load-carrying capacity of the structures.
14 I think we've talked about the large-scale 15 test program in the past, but I really want to just 16 get to the results of this test program. You know, 17 they placed test beams, tested them to failure. So, 18 the results of the test program showed, No. 1, there 19 is no reduction in structural capacity at the 20 expansion levels tested. Right? So, there was clear 21 guardrails up to that expansion level that is tested.
22 It doesn't tell anything about the structure after the 23 expansion levels that were tested. Right?
24 So since, within the expansion levels 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
32 tested, they can use the code equations that can 1
continue to be used up to the tested experience 2
limits. It also found that the expansion plateaued in 3
the X-Y direction due to reinforcement, and then, 4
continued through-wall, which lacks reinforcement.
5 So, it starts cross-plane, and then, once it hits a 6
threshold there, it starts going through-wall.
7 And then, based on that, it was determined 8
that expansion, specifically, through-wall expansion, 9
was the best parameter for tracking ASR progressions 10 in their structures. So, they determined though-wall 11 expansion. The test results were used to really 12 develop the expansion limits and monitoring 13 techniques, which were incorporated into Seabrook's 14 current license basis via the licensing amendment.
15 So, as long as Seabrook stays below the 16 identified expansion limits that were determined in 17 the Texas testing, they can continue to use the 18 original design equations and material properties to 19 determine the capacity of the impacted concrete. If 20 they go outside these limits, it does not necessarily 21 mean they are unsafe. It just means that we don't 22 know. Right? Up to the expansion that they tested, 23 we do have confidence in the structural capacity of 24 those members.
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33 As we stated earlier, ASR degradation was 1
not previously addressed in their license. So, they 2
did come in for a license amendment request. They 3
updated their license amendment to incorporate the 4
expansion limits and get approval of the methodology.
5 So, we talked a lot about the methodology document, 6
which was then incorporated into Their Structures 7
Monitoring Program. And Nik will talk a little bit 8
more about the Structures Monitoring Program to 9
analyze the structures affected by alkali-silica 10 reaction.
11 They also updated their license renewal 12 application to include those activities, and then, 13 following extensive review, the NRC approved the 14 license amendment, followed by the renewed license, in 15 March of 2019. It included peer reviews from other 16 offices in the NRC; use of expert contractors from a 17 National Lab, as well as reviews by the ACRS.
18 And then, lastly, we just want to point 19 out that the LAR was challenged by a local advocacy 20 group. It was seen before the Atomic Licensing Safety 21 Board and was adjudicated in November of 2020 with a 22 few additional License Conditions that were added on 23 as part of that contested license amendment request.
24 So, with that, I will turn it over to Nik, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
34 unless there are any questions before we move on.
1 (No response.)
2 MR. FLOYD: Thank you, Travis.
3 Can you hear me okay?
4 CHAIR HALNON: Mm-hmm.
5 MR. FLOYD: Okay. So, as Travis said, ASR 6
was not part of the original licensing and design 7
basis. After the license amendment request and the 8
license renewal application went
- through, the 9
Structures Monitoring Program, which is normally 10 implemented under the Maintenance Rule Program, was 11 enhanced to include three additional programs specific 12 to managing the effects of ASR.
13 The first program is the ASR Aging 14 Management Program. This program was based off the 15 large-scale test program. It deals with just the 16 capacity side of the concrete strength design 17 equation. And really, what it does is it just ensures 18 that the structures stay within the bounds of the 19 expansion levels that were tested during that large-20 scale test program.
21 How is that monitored? Well, it's 22 monitored through the ASR grids. During the 23 walkdowns, you saw the grids on the walls. That's the 24 in-plane measurements. Originally, that used crack 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
35 indexing. Now, they use pin-to-pin because it's more 1
reliable, as well as the extensometers, which is the 2
through-wall measurement direction. Those two develop 3
not just through-wall expansion, but, also, when you 4
add in the pin-to-pin in-plane, that gives you a full 5
volumetric expansion limit.
6 So, that is literally the heart and soul 7
of the ASR Monitoring Program, just to ensure that the 8
volumetric expansion stays within the large-scale test 9
program.
10 The second program is the Building 11 Deformation Aging Management Program. This all 12 revolves around the demand side of the concrete 13 strength design equation. What this does is now look 14 at the structural demand.
15 So, this is basically using a three-stage 16 progress, stage one to two to three, which looks at 17 the concrete design equations for the structures.
18 Stage one, starting with the least complex, using the 19 original design calc or design inputs, then adding in 20 a conservative ASR load, all the way up to stage 21 three, which is the most complex, which is finite 22 element modeling, where they do field walkdowns and 23 calibrate the model back to what is observed in the 24 field.
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36 And how is monitoring handled for this 1
program? Well, it uses the ASR Monitoring Program 2
elements, which are the in-plane expansion, as well as 3
the extensometers, and then, they also use crack 4
measurements, which could be crack widths. It could 5
be through vertical or horizontal directions on 6
specific areas of the wall, as well as seismic gaps, 7
and building dimensions. Building dimensions could be 8
wall-to-wall. This could be the plumbness of the 9
wall. It could even be a height measurement from the 10 bottom of the wall to a certain point.
11 So, all of that goes back into the 12 Building Deformation Program based off of the 13 analysis. And what we call those monitoring areas are 14 threshold limits. I shouldn't say, "what we" -- what 15 the licensee calls them. And when they do the 16 structural analysis, those threshold limits are 17 established based off critical areas of the structure.
18 So, when they do the finite element model, 19 you identify the areas that had the least amount of 20 margins. Those are considered the critical areas, and 21 those are the ones that are monitored just to ensure 22 that the analyzed demand stays within the capacity.
23 And then, the third program is the 24 equipment impacted by the building deformation. So 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
37 again, as Travis was alluding to during some of our 1
inspections, what we're starting to see now -- or not 2
starting to see, but have seen -- are various 3
equipment that are connected to one structure and also 4
connected to another structure.
5 Well, as you get this bulk ASR deformation 6
over time, that differential movement can impact those 7
connected components. Some components would be, like, 8
electrical conduit. They can be structural supports 9
for tubing or even piping. And once those are 10 impacted, then they have to be evaluated.
11 So, this program is mainly conducted 12 through visual examination of equipment, and then, the 13 acceptance criteria, it depends on the type of 14 component it is. For electrical conduit, they have 15 maximum displacements that that conduit can handle.
16 They also call them seismic isolators. But if they go 17 beyond a certain deformation, then they have to take 18 corrective action.
19 If it's component support, like for 20 tubing, and it touches the structure, well, that has 21 to be corrected. You have to have a minimal seismic 22 gap for that, just based off the analysis.
23 So, really, it's these three programs 24 enhanced and implemented under the umbrella of the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
38 Structures Monitoring Program that Seabrook uses to 1
monitor and manage the effects of ASR.
2 CHAIR HALNON: So, Nik, a couple of 3
questions.
4 MR. FLOYD: Yes.
5 CHAIR HALNON: Aging Management Program, 6
could you give just a few seconds on what is an aging 7
management program?
8 MR. FLOYD: Yes.
9 CHAIR HALNON: I mean, is it a series of 10 procedures? Is it a big notebook? Is it a computer 11 program? Or is it all of the above?
12 MR. FLOYD: Okay. And should have added, 13 I noted that these are aging management programs.
14 Normally, aging management is reserved under the 15 context of license renewal. In Seabrook, their period 16 of extended operation for the end of their 40-year 17 license isn't until 2030, but they're implementing 18 these aging management programs now.
19 And what these are, essentially, it's a 20 composite of the Structures Monitoring Program, which 21 is a program at large. There's an entire manual 22 dedicated to this. And each one of these are just 23 chapters within that program manual.
24 Within that is a set of guidelines, which 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
39 includes the 10 elements of a license renewal aging 1
management program. So, you have the scope of the 2
program. So, what components are covered? It also 3
has guidelines for monitoring. It has acceptance 4
criteria, trend, corrective actions, and then, the 5
procedures that are used to perform that monitoring.
6 That's from data collection to data evaluation, and 7
then, again, acceptance criteria and corrective action 8
if you exceed that acceptance criteria. So, it's a 9
whole suite of procedures, guidelines, and all under 10 the same program manual, if that helps.
11 CHAIR HALNON: Yes, that does.
12 Given all that, the minor earthquake that 13 was felt in January, what did that trigger, if 14 anything, in this program? Did they go out and get 15 new measurements? Was there any analysis done? Or 16 was it just below the level of concern, that it was so 17 small and just a point?
18 MR. FLOYD: I'll cover the quick technical 19 side, and then, I'll hand it to Travis, because he can 20 handle the plant's operational response.
21 So, that earthquake was well below the 22 plant's design basis earthquake level. So, there's a 23 safe shutdown earthquake level, which is the most 24 limiting, and then, the operating basis earthquake, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
40 the OBE, which, essentially, is a plant can handle 1
that load, that seismic load, and still continue to 2
operate. They were well below the operating level.
3 So, technically speaking, they're well 4
within the bounds of their analyzed limits for these 5
structures. So, under the Structures Monitoring 6
Program, they're not required to do any re-analysis.
7 Now, in the procedures -- and I'll let 8
Travis speak to this -- operationally, they will be 9
queued to do system walkdowns to look for any changes 10 such as cracks in concrete, displaced equipment. But 11 it's within -- I can't remember which procedure it is.
12 MR. DAUN: Yes, there was one point within 13 one of their steam chases that they did have a 14 compensatory action. It is part of their ASR program 15 to go down and do a hammer test following any seismic 16 activity at the site.
17 So, they did go down and do that hammer 18 test just to look for any delamination of the concrete 19 within the wall. They didn't identify anything. They 20 didn't think they would, but they went. They did the 21 hammer test. That was the only thing that was called 22 no because it was so low.
23 Now, they did, as Nik said, they did do a 24 lot of equipment walkdowns. They walked down, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
41 basically, all of the safety-related equipment, just 1
to validate, you know, that there wasn't any abnormal 2
conditions.
3 But the only thing directly required --
4 and it was part of an evaluation within their ASR 5
program -- was to do the hammer test in one area for 6
delamination.
7 CHAIR HALNON: And how did you monitor 8
what they did? Did they report to you or brief you on 9
the results of all the walkdowns?
10 MR. DAUN: So, yes, they're very good 11 about reporting the hammer test. I'll tell you, at 12 the time, we were unaware that the hammer test was 13 even occurring. I had walked into them doing the 14 hammer test as I was doing my walkdowns and thought it 15 was very interesting. "Well, what are you doing?"
16 And they're like, "Oh, this is the compensatory 17 requirement we have for" -- you know.
18 So, we would have looked at it eventually, 19 but it was fortunate that we just happened to be in 20 that area when they were doing it, if that makes 21 sense.
22 MR. FLOYD: Next slide.
23 So, under each one of those aging 24 management programs, there are methods to monitor.
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42 Right? This is how the licensee needs to implement 1
those programs. So, this slide is just giving a 2
representation of various examples of how that's 3
accomplished.
4 The top left is an ASR grid. In this, 5
they used to perform combined crack indexing or 6
otherwise known as CCI. Now, the more repeatable, 7
reliable, just a lot more efficient because there's so 8
many grids around the site, is the pin-to-pin. This 9
is designed just for in-plane expansion and this is 10 covered under both the ASR monitoring, Aging 11 Management Program and the Building Deformation 12 Program.
13 To the top right, that's a seismic gap 14 example between buildings. There are -- I don't have 15 the exact number -- it's on the order of 20 to 30 16 seismic gaps around the site. That, again, is 17 utilized to implement the Building Deformation 18 Monitoring Program. And essentially, you're just 19 measuring the distance from the one building to the 20 other.
21 And the original design of the seismic 22 gaps is that these are separate structures and they 23 require a certain set distance for seismic isolation.
24 Under the Building Deformation Program, those areas 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
43 were identified. The ones that they chose as critical 1
areas is because they helped monitor the overall 2
growth of the structure, as part of the building 3
analysis that was performed.
4 For the bottom left, that's an example of 5
an extensometer. What you're looking at is just a 6
cover of the extensometer. That's to help provide, 7
basically, protections, so that this instrumentation 8
does not get otherwise damaged, bumped, or otherwise 9
invalidated. So, the cover is there just for a simple 10 physical protection.
11 The diagram next to it is actually what 12 the through-wall representation or the side plane 13 looks like. It's anchored at the front and the rear 14 rebar mats and just provides an indication of the 15 through-wall expansion. There are no electronics 16 involved with this. This is purely a mechanical 17 strain gauge.
18 This was also demonstrated during the 19 large-scale test program. They tested various 20 extensometers for longevity, reliability, and just 21 overall accuracy. This is a snap-ring borehole 22 extensometer. This is what the licensee determined 23 was the best instrument to measure through-wall 24 expansion through the life of the plant.
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44 And we have not seen any indication that 1
their not performing appropriately. They continue to 2
monitor expansion levels as one would expect.
3 The last example -- and these are not all 4
the examples; these are just a set, a selection -- but 5
the bottom right is an example of a crack gauge. You 6
simply place this over a crack, and then, there's a 7
small -- it's kind of hard to see in this photo, but 8
it's just a small scale to show you any displacement 9
or movement of that crack.
10 There are other types of informal crack 11 widths also performed. So, it's part of the 12 structural analysis at certain set areas that were 13 identified as critical. There might be monitor this 14 size or this width crack over a set distance at is 15 this elevation for what would be expected per that 16 loading of the building, whether it's bending load or 17 a shear load, to look for that particular loading 18 configuration. And if the licensee were to see that 19 as part of their monitoring, that would kick them off 20 to do a re-analysis.
21 Next slide.
22 CHAIR HALNON: Yes, let's go back just a 23 second, Nik.
24 The seismic gap, they're watching for it 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
45 to close up because this is expansion. What do they 1
expect to see with ASR? I mean, is there an 2
acceptance criteria that puts them into -- that's Tier 3
3, or whatever you said, stage three?
4 MR. FLOYD: So, for the seismic gaps, 5
initially, they were walked down just to ensure that 6
there was still seismic isolation between the 7
buildings.
8 One of the early-on retrofits or physical 9
modifications was in the CEVA annulus. Between the 10 CEB, the containment enclosure building, and the 11 primary containment building, there were these 12 concrete missile shield blocks that protected safety-13 related piping below. Well, because the containment 14 enclosure building had actually physically deformed in 15 a bulk manner, that missile shield block was touching 16 the containment structure. So, they had to restore 17 those gaps.
18 So, the first walkdowns were just to 19 ensure that all the seismic gaps were retained. Now 20 what they're looking for is that the seismic gap, 21 basically, the material itself is intact. In some 22 instances, the gap is closing due to the differential 23 movement; in some instances, it's widening. So, 24 they're looking for both a closing and an opening.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
46 And under the Building Deformation 1
Program, most of that monitoring is done inside the 2
plant. They're just looking at the distance, just to 3
ensure the movement, or lack thereof. Because it's 4
used as an input into their structural analysis. So, 5
when they did the finite element model, they can see 6
where the displacement is and they use that as an 7
input to be monitored.
8 CHAIR HALNON: And that's how they go back 9
and verify their analyses, by looking at the specific 10 what has really happened in the field? Go back into 11 the analysis and make sure that that's either 12 calibrated, so that's the same thing, or it verifies 13 that the model was correct?
14 MR. FLOYD: That is correct.
15 CHAIR HALNON: Okay.
16 MR. FLOYD: And seismic gap, that's just 17 one example of a physical building measurement. Other 18 ones are, for example, like in the electrical tunnel 19 or even in the containment internals, reactor cavity 20 pit, they do a wall-to-wall measurement looking at the 21 distance between two adjacent structures. Yes.
22 So, as part of the aging management, 23 obviously, you have to monitor whatever the parameters 24 are. You have acceptance criteria. Well, there's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
47 also a corrective action piece.
1 The left is a proactive corrective action 2
performed by the licensee. This was on the fuel 3
storage building, where they did a structural 4
analysis. The building was actually well within the 5
structural capacity as far as the demand-to-capacity 6
ratio and had additional margin for future expansion.
7 But due to ease of access and, also, building a 8
proficiency for the maintenance step that they had 9
performing the mechanical modifications, they targeted 10 this structure first.
11 This was part of the walkdown that you had 12 today and it's just an example that this building in 13 this particular area, one of the load paths where they 14 were seeing additional ASR loads was in the vertical 15 expansion direction. So, that was going to be, if it 16 ever got there, one of the more limiting parameters 17 that they had to basically maintain.
18 And so, to combat that, the modification 19 that they targeted were these vertical plates.
20 Essentially, you could consider them external rebar.
21 And you can't see below it because it's excavated and 22 now it's been refilled-in, but it goes below the 23 ground
- level, and that just resists vertical 24 expansion.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
48 So, this was a proactive modification, but 1
it is an example of a type of physical modification 2
that can be performed at the site.
3 And also within the picture, and as shown 4
today, is they still maintain the original monitoring 5
parameters under the ASR Aging Management Program.
6 So, just because you do a modification doesn't mean 7
you have to stop monitoring for ASR expansion. That 8
still has to be maintained as part of that one Aging 9
Management Program.
So, there's still the 10 extensometer and there's still the ASR grid that they 11 have to monitor at that set frequency.
12 The picture on the right, this was a 13 reactive modification. So, this is an instance where 14 the building was being monitored. They had critical 15 points. They were coming or imposing upon those 16 limits, and then, the only way to actually physically 17 oppose that or correct that was through a physical 18 modification. There was no further re-analysis that 19 could be performed to show that this particular wall 20 on this particular structure would be acceptable.
21 So, in this instance, they used a 22 combination of physical modifications. One was 23 through-wall reinforcement. It's kind of hard to see, 24 but you can see the squares with the circles; that's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
49 actually me squatted down there in the photo. That's 1
a through-wall reinforcement, and then the triangular 2
braces that go from the wall to the floor also 3
providing additional, basically, bending resistance or 4
- yeah, bending resistance for the wall.
5 So, those are two types of modifications 6
implemented in the mechanical penetration building.
7 I didn't show the other wall, but there was a second 8
wall that was also physically modified. This was a 9
structure that was originally outside of the design 10
- basis, which put it into prompt operability 11 determination space. It now has been restored and it 12 has margin for additional expansion as ASR, if it were 13 to continue to grow.
14 Next slide, please. So, here, I just 15 wanted to kind of give you a general - I know we've 16 already discussed this or Travis covered some of the 17 items that the NRC Residents perform and the NRC 18 Reactor Inspector such as myself and team inspection 19 perform. But I just wanted to give a quick recap.
20 So
- here, since
- 2020, the NRC has 21 identified -- and these are NRC Inspector-identified 22 findings -- a total of five findings. They've all 23 been a very low safety significance. That means they 24 were, under the reactor oversight process, determined 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
50 to be green. And that's just because in each one of 1
those instances whatever the component or the 2
structure were demonstrated to remain functional 3
and/or operable. So, under our process, it screens to 4
very low safety significance.
5 Also, for each one of these findings, 6
anytime we do identify something, the licensee has put 7
that into their Corrective Action Program. And when 8
we come back for the future inspection, one of the 9
things that I like to do, and the Residents also look 10 at under the CAP, is: what corrective action was 11 actually taken? Has the licensee addressed that?
12 And in each one of these cases for the 13 five corrective actions, or the five findings, they 14 have taken corrective actions to address those. So, 15 that's the overall assessment.
16 Just real quick, since the last time we 17 had a discussion with you all -- that was September of 18 last year -- we have performed -- technically, we've 19 completed both these inspections, but only one of them 20 has been publicized in an Inspection Report. That's 21 the 2024004. So, for our fourth quarter of last year.
22 For that, the scope of that inspection was 23 a review of the condensate storage tank enclosure.
24 This is a reinforced concrete enclosure around the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
51 condensate storage tank. In this instance, it was 1
still within its ability to perform its function. It 2
was still well within the structural demand and 3
capacity, but it had threshold limits that the 4
licensee was monitoring. These were ASR grids that 5
were approaching the limits.
6 As part of the initial evaluation that was 7
performed for this, the licensee just looked at the 8
original design calc and incorporated conservative ASR 9
loads for this. Well, as part of their effort, they 10 wanted to reevaluate the structure. Part of the 11 process, they called it a re-baseline. That was using 12 more up-to-date ASR monitoring data as part of their 13 evaluation.
14 So, they performed a stage two structural 15 analysis, which was a finite element model, and they 16 also used the most up-to-date ASR expansion to 17 actually use that as the input into the model.
18 This was well within the methodology.
19 It's also within the Building Deformation Program. As 20 I said, there's three stages that could be performed, 21 and they opted to use a stage two approach for this.
22 So, we did review the inputs for that 23 analysis. We did walkdowns. We also looked at a 24 history of their ASR monitoring data up to that point, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
52 just to ensure that the assumptions and inputs that 1
they used in that evaluation were appropriate.
2 And then, the second piece of that is we 3
don't look at this every inspection because we only do 4
a sample at a time, but we wanted to review the ASR 5
expansion data to date. So, this was a look at the 6
threshold -- or not threshold -- but the through-wall 7
monitoring. These are the extensometers. We wanted 8
to look at what the extensometers were now, so that's 9
margin to the large-scale test program limits, as well 10 as what are they trending to.
11 So, that was something we identified a 12 couple of years ago and we just wanted to do a 13 touchpoint to see, hey, are they still on track? Do 14 they have a test program they plan to implement? Are 15 they still going to be within their bounded analysis 16 prior to completion of that program?
17 So, the trends, basically, aligned with 18 what they had just performed. So, we did not have any 19 issues with either one of those samples.
20 And the most recent inspection was the 21 first quarter of this year. While not publicized yet, 22 it will be available here very shortly. But this was, 23 actually, a very big inspection for us.
24 The first one was addressing License 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
53 Condition Bravo for ASR. This was the corroboration 1
study, which, essentially, looks at their ASR. Right?
2 When they did the large-scale test program, they 3
developed correlations between ASR expansion and the 4
concrete elastic modulus.
5 So, for that
- testing, for this 6
corroboration study, they took several core samples 7
from approximately 20 percent of the currently 8
installed extensometer locations, and then, did 9
testing to verify that the correlation between elastic 10 modulus and expansion still is similar to the large-11 scale testing program correlation trends.
12 The second piece of this was the 13 containment internal structure reactor pit temperature 14 data. So, this was the temperature that they had as 15 an input to their original analysis or their revised 16 analysis, that had an assumption that was not 17 previously measured.
18 During the last outage, they installed 19 data loggers with ambient temperatures. They 20 collected that over a cycle, and then, reviewed that 21 data during their most recent refuel outage for the 22 fall of last year, and just ensured that there were no 23 significant differences.
24 And then, the last scope of this was in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
54 the RHR vaults. They have vertical expansion that, 1
through their own structural analysis, showed that 2
they were approaching the rebar stress limits. Part 3
of their ASR License Condition Delta is to ensure that 4
they have a monitoring program in place, so that they 5
don't yield rebar, or that if they do yield rebar, 6
failure is detected.
7 So, part of this was looking at this test 8
program where they performed micro-drilling and 9
cutting of rebar on a sample of rebar locations in the 10 RHR vault to ensure that they did not approach and/or 11 yield any vertical or horizontal rebar.
12 So, from that Inspection Report, I can 13 tell you we identified no inspection findings and they 14 addressed multiple License Conditions.
15 CHAIR HALNON: So, over the years, the 16 findings have not all -- I mean, they've been 17 associated with ASR. That's why you're highlighting 18 them. But a couple of them have been programmatic 19 elsewhere, like prompt operability determinations and 20 the PI&R. Have you seen sufficient improvement in 21 those programs to have confidence that they have 22 plugged whatever holes that caused those programs to 23 stumble?
24 MR. FLOYD: Yes, very much so. You know, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
55 each one of those findings -- a better way I can say 1
it is, the only common issue that we found is that the 2
word or the phrase "ASR" is in there. Each one of the 3
issues are separate in its nature. They each revolved 4
around a different performance deficiency. And the 5
licensee has taken corrective action to improve upon 6
it.
7 One of the early-on findings was an issue 8
with the operability determination and trending of 9
expansion data, where we identified that they weren't 10 trending the collected ASR monitoring data. So, how 11 could you track timely corrective actions?
12 Since then, everything they have, they 13 have a trend for. So, they took it and ran with it.
14 And now, they're using that to inform their, 15 basically, work order tracking and prioritizing which 16 work gets attention first. So, that's one area where 17 they have taken it and run with it, and I'm very 18 comfortable in what they're doing now.
19 For the others, again, they're just kind 20 of smaller implementation issues. One of them, they, 21 as far as the extensometer, installed extensometer 22 locations, they have chocked up to a legacy issue.
23 Again, since then, they've put appropriate protocols 24 in place to ensure that doesn't happen again.
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56 So again, part of Travis' review of the 1
Corrective Action Program, he shared with me where one 2
or two areas went from a Tier 2 to Tier 3. This is 3
the ASR monitoring grids. And now, they have a work 4
order tracking extensometers location. So, they have 5
mechanisms in place to, basically, prevent that from 6
happening again.
7 So, from what I've seen -- and again, not 8
every year is five findings. There was one, one year; 9
two one year; None one year. It's kind of up and 10 down. But I would say it's consistent with the rest 11 of the plant performance and it's not isolated just to 12 ASR.
13 There's a lot on this slide. I do not 14 intend to read each one of the ASR License Conditions.
15 I just wanted to give a quick summary, just because 16 this is now part of Seabrook's operating license; and 17 also, to kind of give you a status of where they're at 18 with each one of these.
19 The first one -- and this one I will read 20
-- this was that "The licensee shall assess the 21 expansion behavior to confirm it's comparable to the 22 large-scale test program." And the second piece of 23 that is to check the margin for future expansion.
24 They completed that first assessment back 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
57 in March of 2018. We did look at that, just to ensure 1
that, yes, the expansion data that they are collecting 2
from the plant is the in-plane expansion and the 3
through-wall matched up with what they tested in the 4
large-scale test program.
5 The biggest thing there that they observed 6
is that it plateaus at a certain point, and then, 7
starts to go through-wall. Again, in 2018, they only 8
had so much run time, but at that time when they 9
performed this assessment, it was on par with the 10 large-scale test program. And per the License 11 Condition, the next one will be within the next 10 12 years. So, that puts them at 2028.
13 License Condition Bravo. This was another 14 very important Licensing Condition added by the NRC 15 staff at the time of the license amendment. This is 16 the corroboration that confirms that the concrete-17 modulus-to-expansion correlation matches the large-18 scale test program. Again, very important because 19 they are using that correlation when they install 20 extensometers to come up with what is the expansion to 21 date, and then, that expansion to date is added 22 through future monitoring to ensure they stay within 23 the large-scale test program limits.
24 So, to say that you have sufficient 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
58 capacity, that correlation must remain valid. And 1
we've identified no issues with that when we've 2
reviewed that in the first quarter of this year.
3 So, that study is now complete and the 4
next one will be in the next 10 years.
5 And then, as far as the remaining License 6
Conditions Charlie through Foxtrot, these are items 7
that we look at pretty much every time we look at the 8
inspection. You know, whether it's checking the 9
expansion, looking at the rebar programs, or the ASR 10 expansion monitoring rates, it's something that's 11 always going to be ongoing. It's not a once-every 12 years. It's a frequent item. So, that's something 13 that I just listed as ongoing because it's something 14 we do every inspection.
15 And I would say, within our last two 16 inspections, from the first quarter of this year to 17 the last quarter of 2024, we looked at all of these.
18 Now, I'll hand it back to Travis.
19 MR. DAUN: We kind of talked about a lot 20 of this before, but we continue to monitor ASR, ASR-21 related activities. They do have a number of 22 structures still in prompt operability determination 23 space that they are doing retrofits. We continue to 24 monitor those, and their methods bring those back into 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
59 the licensing basis. We monitor building deformation 1
and completing modifications.
2 So, I think that is what we have, you 3
know, pending any questions.
4 CHAIR HALNON: Members, any questions?
5 MEMBER HARRINGTON: So, as they've done --
6 you lost your identity -- as they've done re-analyses 7
of the various structures, have you had good access to 8
audit their calculations and that kind of thing?
9 MR. FLOYD: Yes. Yes. Part of the re-10 analysis, when we select a structure for review, the 11 first thing we ask for is a copy of their design 12 calculation. We ask for a copy of the original one, 13 and then, we also ask for a copy of the revised one.
14 In addition to that, we ask for a copy of 15 the Site Visit Report, which includes the field data 16 that they used as an input for that design calc.
17 And then, also, as part of that, we 18 request -- because NextEra themselves, they don't 19 perform these structural evaluations in-house. They 20 contract it out to a structural engineering firm, and 21 then, the structural engineering firm is the one who 22 actually performs the modeling, the analysis.
23 So, they bring their contractor onsite and 24 we actually have one-on-one discussions with them and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
60 their staff, such that we can ask those questions. As 1
part of the modeling, the design inputs, why did they 2
do this? Such that we have an open back-and-forth 3
just to understand what they performed.
4 CHAIR HALNON: Any other questions?
5 (No response.)
6 CHAIR HALNON: So, just one real quick, 7
but maybe it's not quick.
8 (Laughter.)
9 CHAIR HALNON: You do these analyses. You 10 do these calculations. The only thing we know for 11 certain is what you see in the field. So, how do you 12 deal with the uncertainties in the calculations and 13 the analyses? Because you can't look at those and 14 say, "That's exactly right." You have to put some 15 kind of uncertainty band around it. So, how do you 16 deal with that in the oversight process?
17 MR. DAUN: I'll tell you how I think and 18 I'll let Nik -- because you bring it up, right, it's 19 a lot of calculations. I am not a structural 20 engineer; Seamus is not a structural engineer. Right?
21 NRR provides structural engineers to come out with Nik 22 to help review those structures.
23 But Seamus and I are in the field daily 24 looking at differences. We know what structures look 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
61 like and it's easy tell when something has changed, 1
especially when it comes to equipment impacts, seals.
2 Seals are usually where you're seeing the issues first 3
and asking those questions, why is this seal starting 4
to tear away? Did you expect that?
5 That's how we're from a 10,000-foot view 6
of ASR -- we're out there actually looking at the 7
structures, looking at these monitoring locations, and 8
being able to know, hey, I don't recall pattern 9
cracking in this area before. I don't recall concrete 10 spalling in this area before.
11 You know, so when we see those things, 12 that's when we start engaging the licensee, for one, 13 are they aware of it? And two, well, why is it 14 occurring?
15 So, that's how I would answer that from 16 the resident offices. We know what it typically looks 17 like and we're pretty good at detecting when there's 18 a change from what we're used to walking through.
19 MR. FLOYD: So, Travis covered the high-20 level in-plant visual. From the technical aspect, for 21 concrete structures, at least for myself and during 22 the reviews, where we see uncertainty being addressed 23 the most is just the inherent margin in a lot of these 24 concrete design calculations -- the first one being in 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
62 the ACI 318, 1871 edition. Right? That's what 1
NextEra and Seabrook are committed to.
2 When you look at each load combination 3
that's required to be analyzed, each one of those has 4
a load factor. Well, I should say not all, though.
5 Most of the load combinations for normal and unusual 6
loads have a load factor combined. That's one safety 7
factor.
8 In addition, for ASR, ASR itself gets a 9
load factor, plus, they have to add in a margin for 10 additional expansion. So, that's from today, plus, 11 additional expansion. That's just one piece of the 12 uncertainty.
13 The second piece would be, for instance, 14 like with extensometers. When they do that 15 correlation, they actually have an uncertainty added 16 within that equation. It's.85. So, they're already 17 raising the level of installed through-wall expansion 18 another 15 percent times that correlation factor.
19 When they take, for example -- so, that's 20 the technical piece. Right? Within each margin --
21 there we go, let me not get tongue-tied -- within each 22 equation, there's already a margin built in. On top 23 of that, on the demand side of the equation, when the 24 licensee did some of these original design calcs --
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63 for instance, like the CST, right? -- they didn't 1
project out to ultimate expansion levels. They just 2
looked at, okay, just throw on 20 percent ASR 3
expansion to the original design loads. Here's the 4
total load demand. It's well within the capacity of 5
the structure.
6 It might be, for certain load 7
combinations, 50 percent. So, they didn't go through 8
and look at what is the 100 percent demand capacity 9
ratio, and then, what is that corresponding ASR load?
10 Or what's the corresponding ASR expansion?
11 So, in many instances, they just projected 12 ahead 20 percent, but they might be able to handle 50, 13 60, 70 percent. They didn't do that as part of their 14 initial effort. So, inherent just within the demand 15 side is also an additional level of conservatisms.
16 That's why, for some of these structures 17 where they're not within their acceptance criteria, 18 they're monitoring it under operability determination 19 limits, they only add 10 percent at a time, but they 20 can keep adding 10 percent at a time for a long time.
21 And the last thing I would say as part of 22 that is, you know, part of the modifications they're 23 doing now, they're taking substantial amounts of core 24 samples from the walls. If there was some type of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
64 undetected, on-the-surface degradation, we would 1
expect to see something within the integrity, you 2
know, within the volume of the wall.
3 When they bore core samples, most of the 4
time they come out as full samples. I mean, 5
sometimes, by inherent nature, sometimes you'll hit a 6
piece of rebar that might mess up that core sample, 7
but the core samples being removed don't indicate any 8
sort of integrity issues with what's going on inside 9
the wall.
10 And that's, I would say that's what's 11 really giving me a lot of additional confidence on top 12 of the modeling. Modeling is modeling. But when they 13 physically remove samples, that's what helps me.
14 So, we don't see mid-plane cracks. We 15 don't see crumbling samples. It's well-consolidated 16 concrete. Yes.
17 CHAIR HALNON: Okay. At this time, I 18 wanted to kind of walk through our technical experts 19 and experts focused on the areas. Will you just give 20 me your impression on what you saw?
21 What we saw this morning was, you know, we 22 started off with about 45 minutes almost to an hour 23 with the Residents drilling them with questions. I 24 mean, how many? We must have asked a thousand 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
65 questions and we got a really good brief.
1 And then, we spent another hour or so, two 2
hours, with the staff right next door. Then, we went 3
out in the field and we validated everything we had 4
just heard with what we saw.
5 And I wanted to ask Dr. Ron Ballinger and 6
Dr. Harrington to give their thoughts about the 7
technical aspects of what we heard.
8 Ron, we do have some of your slides here.
9 MEMBER BALLINGER: Yes, we have -- the 10 first two slides are pretty redundant. So, let's just 11 go through and see.
12 Okay. This is something that we've seen 13 already today, which describes the process. Up at the 14 top, it's the silica reaction, and then, the bottom 15 three slides, three figures are just descriptions of 16 where we see it and examples of it.
17 So, let's go to the next slide. That's 18 another one. We see this surface cracking. Again, 19 this is one person's opinion again. We need to be a 20 little bit careful when we see that. Most concrete 21 structures have 2 to 4 inches of what's called cover 22 on the rebar. And that's unconstrained expansion.
23 So, you get cracking there. That does not mean 24 there's cracking inside, because the rebar that's 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
66 inside, when you get expansion, actually puts it in 1
compression.
2 So, be a little bit careful when we make 3
an assumption that, oh, my goodness, this is going to 4
be bad inside. It's not necessarily the case.
5 So, next.
6 CHAIR HALNON: Is the reverse the case?
7 Can you have it inside and not have it on the outside?
8 MEMBER BALLINGER: I've not seen that.
9 Okay. So, I thought about, since this is 10 the Advisory Committee on Reactor Safeguards, what are 11 the safety implications from my perspective?
12 First off, it progresses very slowly, 13 which means there's not some threshold that we're 14 going to go through; all of a sudden, things are going 15 to get really bad.
16 It's limited to the high-silica aggregate.
17 When we went out there to see it, it's limited to 18 local regions. And I thought about that. This 19 aggregate came from Maine. And if you've ever been to 20 Sunday River, you'll probably know what I'm talking 21 about.
22 But granite that's up there is laid down 23 in layers by volcanic action, like, a couple of 24 hundred million years ago, or whatever it was. And 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
67 so, the composition will be layered in terms of 1
composition. So, when they mine the granite, it's 2
entirely possible, in one person's opinion, that you 3
can get compositional differences, depending on where 4
you -- what shovel you use, as a matter of fact. And 5
that might impact the fact that we see it locally.
6 It's manageable.
As part of the 7
discussion, that's all we've been talking about, is 8
that it's manageable. It's slow. There's a 9
management program in place which is very extensive 10 and very well-monitored.
11 We have not seen any indications of rebar 12 degradation, which is important. If anybody has 13 driven from Logan Airport up Route 93 or Route 95 or 14 495, and gone under some of those overpasses, you'll 15 know exactly what I'm talking about when I'm talking 16 about rebar issues.
17 There is building displacement that 18 affects the seismic gap, but that's being dealt with.
19 We've heard the discussions about what's been 20 happening for that.
21 But the important thing is the 22 verification of adequate safety margin, and that we've 23 had a big discussion about, a long discussion about as 24 well.
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68 And that required the implementation of 1
this monitoring program, which is going to be going on 2
for as long as the plant exists.
3 So, with that, I'll turn it over to Craig.
4 MEMBER HARRINGTON: The only thing I would 5
add is
- that, from a
degradation management 6
perspective, they have the right pieces in place of 7
understanding the problem; characterizing in an 8
engineering way the appropriate parameters; factoring 9
those into their calculations; making plant 10 modifications, and then, monitoring and feeding that 11 back into the process to continue to update their 12 results and make sure that they're staying within the 13 bounds of their analysis, or not, and then, adjusting 14 accordingly.
15 So, they have all those pieces in place 16 and it's, not to be trite about it, but it's an 17 implementation thing at this point, and they have to 18 keep at it and make sure that -- and you guys are 19 watching them -- make sure they go through that 20 process effectively and efficiently on a continuing 21 basis.
22 MEMBER BALLINGER: I have one more thing.
23 I have one more thing to add.
24 During our discussion, I coined a little 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
69 bit of a phrase and said that this whole process that 1
we've been dealing with is what I would call 2
"engineering convergence." What does that mean?
3 What it means is that you've discovered a 4
problem, and if you own a house -- my house is 180 5
years old -- you know what I'm talking about. You 6
eventually solve the problem by an iterative process, 7
and eventually, you converge on a monitoring program 8
which implements and actually covers all the bases, 9
some of which you didn't know about when you initially 10 saw the problem.
11 CHAIR HALNON: Since you guys are both 12 theoretical, academic, and practical, I mean, you've 13 got the full breadth of experience, what about testing 14 data? Do we need more testing data or is this so well 15 understood now, and we can analyze it forever, and not 16 have to worry about testing?
17 MEMBER HARRINGTON: The understanding that 18 I have from the SER, from the license amendment, from 19 the discussions today, they are working within the 20 test data that they have now, but as they approach the 21 bounds established by that test data, it may be 22 necessary either to obtain further test data that 23 allows them to open up that set of bounds further or 24 take other compensatory measures to remain within what 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
70 they know now.
1 CHAIR HALNON: Okay.
2 MEMBER HARRINGTON: But they did not, as 3
I understand it, run those tests to some logical 4
extreme that you can't surpass. So, there's still 5
latitude to go back and do further testing with more 6
extensive ASR-related effects and open up a bigger 7
box, basically.
8 CHAIR HALNON: So, in essence, it's a 9
little bit like what we mentioned earlier. When you 10 take the empirical data from the field, you go back 11 in, and you're going to validate your models and 12 validate your analyses. That's got to all be done 13 again probably when you reach the bounds of where 14 you're at right now with the analyses?
15 MEMBER HARRINGTON: Correct, yes.
16 CHAIR HALNON: Questions for our technical 17 people?
18 (No response.)
19 CHAIR HALNON: Okay. I'm going to ask Tom 20 Roberts and Scott Palmtag to discuss what they saw 21 from an organizational perspective.
22 MEMBER PALMTAG: All right. Thank you, 23 Greg.
24 As Greg mentioned, we had a four-hour tour 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
71 and discussions at the plant today. And Tom and I 1
were tasked with looking at the management 2
effectiveness and to start asking questions about 3
that.
4 So, I thought it was a very productive 5
meeting. The first thing we did was kind of talk 6
about the history of the ASR. I won't go through it 7
again, but it's been around since 2009. Both the NRC 8
and the utility have learned a lot through that 9
process. It's been about 15 years.
10 And you kind of start out with ASR. You 11 know, we see something. What is this? We investigate 12 it. We find out more information. How do we deal 13 with it? And then, you find out better ways to deal 14 with it. So, this has been an ongoing process for 15 about 15 years.
16 The major changes were since the license 17 amendment was submitted in the 2016-2019 timeframe.
18 I won't talk about what happened before there.
19 But they implemented the license, or they 20 submitted the license amendment, and then, there have 21 been some challenges and some learning implemented 22 after the plan. We learned today from the NRC 23 Inspectors, and also from the staff, that there's 24 currently about 50 ASR entries that they go through 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
72 per year.
1 Since 2020, they've found five NRC 2
findings, which corresponds to about one per year.
3 All the findings were low safety significance, but you 4
still have a finding and it's still significant.
5 However, when you compare it to the total amount, 50 6
per year, they're getting about one CAR per year.
7 It's a significant number, but it is small compared to 8
the total amount.
9 And then, I was also very happy to hear 10 that the plant does take ownership of these findings.
11 They didn't argue about it. They didn't try to pass 12 the buck. They didn't blame somebody else. They did 13 take ownership of the findings and try to correct 14 them.
15 As they've been learning more about ASR, 16 especially in the last five or six years, there's been 17 a lot more oversight and involvement from NextEra.
18 One of the things is that, you know, it's important 19 that the sites still maintain the leadership on the 20 ASR. The site knows more about it than anyone else.
21 They have the most experience.
22 But it was nice to see that there was more 23 oversight and involvement from NextEra. NextEra has 24 much more organizational skills and they can bring 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
73 some of those skills in and implement them with the 1
site, and improve the programs.
2 They recently came in, performed an 3
internal audit with an experienced manager. They 4
found issues in there. Again, it's a learning 5
process. The site discovered these issues themselves.
6 They implemented some changes.
7 We found out that they had frequent 8
meetings with the ASR team. I don't think I can say 9
the number outloud, but it is frequent meetings with 10 the site VP and ASR team. So, the ASR is getting lots 11 of visibility within the site and it's being taken 12 seriously.
13 They show an org chart that shows how many 14 people are affected by the ASR problem. There's 21 15 people. Now, these aren't 21 people full-time, but 16 there are 21 people on staff who are affected by the 17 ASR problem.
18 And then, we're also happy to see that 19 there was a single point of contact for technical 20 issues. There was somebody you can go to who sort of 21 owned the issue for the site, who if they didn't know 22 the answer, they could point you to the right person.
23 And so, from what we heard, I'm going to 24 stress that it was just a four-hour meeting. You 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
74 know, we didn't go in and do a multiple-day deep dive.
1 But from what we heard at this meeting, we felt that 2
the management was very dedicated to the monitoring 3
program.
4 And I think many people have said this 5
before: this problem is not going to go away. It's 6
going to take continued oversight, and there's 7
continued oversight from the NRC Inspectors. You'll 8
hear from the NRC Inspectors. They're going to 9
continue watching this problem for the life of the 10 plant.
11 So, thank you.
12 CHAIR HALNON: So, one of the issues with 13 these types of problems that plants deal with long-14 term is knowledge management. Did you see sufficient 15 depth in their organization, or at least breadth 16 across the board, to have some confidence that, if 17 somebody got hit by a beer truck tomorrow, that this 18 would carry on?
19 MEMBER PALMTAG: Yes. Yes.
20 Tom, do you want to answer that?
21 MEMBER ROBERTS: Yes, I asked that 22 question to the single point of contact, you know, who 23 was he mentoring. He said there's at least two people 24 who are following closely what he is working on.
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75 There's another manager who is equally into the 1
technical issues as he is.
2 So, it does appear that they're looking at 3
succession planning and trying to reserve their 4
technical expert as the one person who, inevitably, 5
will retire or go do something else at some point.
6 CHAIR HALNON: Any questions for these 7
folks?
8 Dave?
9 MEMBER PETTI: I just wanted to clarify 10 what I thought I heard. You know, these corrective 11 actions and the ones that were ASR-related, I mean, 12 many, almost all of these are of low safety 13 significance.
And it relates sometimes to 14 administrative issues, procedure, you know, where 15 something wasn't followed exactly to the procedure.
16 But None of them rose to the level of this is a safety 17 issue per se.
18 Everybody's corrective action program 19 across the fleet have these types of issues. It's not 20 abnormal to get the numbers that you see.
21 Is that -- I don't know, but I'm asking 22 you operations guys.
23 CHAIR HALNON: Well, first of all, let's 24 clarify. The low safety significance green is an ROP 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
76 classification for the level of safety impact. It has 1
PRA-type implications to it, if those things would 2
apply.
3 But, also, those PRA implications look at 4
-- and, Vicki, you can help me; you're the PRA expert 5
-- but you have to kind of remove that, too, because 6
that's failed. And then, you decide. And if it's so 7
far away from failure, it starts to screen lower and 8
lower.
9 But Travis, and Nik, and maybe Nate would 10 be better.
11 When you run things through --
12 MR. BURKHART: Can we stop for a second?
13 We've had the audio drop online.
14 (Whereupon, the above-entitled matter went 15 off the record at 3:29 p.m. and resumed at 3:31 p.m.)
16 CHAIR HALNON: I guess I was going to ask 17 you guys, just take a finding like this and run it 18 through the screening process really quick to discuss 19 how it gets to green. You're not going to run a full 20 PRA or analysis on this. So, how does something like 21 this screen out down to a green?
22 MR. DAUN: Right. Yes, we can kind of do 23 that.
24 I
just wanted to make one simple 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
77 correction first, though. Green is very low safety 1
significance.
Just we're saying low safety 2
significance.
3 CHAIR HALNON: It's very low?
4 MR. DAUN: Very low is what green is. So, 5
you know, just to keep it quantified.
6 CHAIR HALNON: Are they hearing us okay?
7 Someone told you it was clear? Okay.
8 Go ahead, Travis.
9 MR. DAUN: Okay. So, when we identify a 10 performance deficiency, we'll run it through our 11 screening process in accordance with our manual 12 chapters.
13 So, most of the violations -- and I can 14 let Nik talk to the specifics -- but the violations 15 that are the performance deficiencies that have been 16 identified, it was determined that they did not impact 17 the functionality or operability of the system, 18 structure, component. So, either that's the structure 19 that's being evaluated, or if it was equipment 20 impacted by that building deformation, it didn't 21 impact the operability of that system, structure, or 22 component. So, even with the performance deficiency, 23 that component would have still been able to meet its 24 safety function.
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78 So, that's kind of where the screening 1
process starts.
2 Do you want to -
3 MR. FLOYD: Yes, just to give you an 4
example, it would be a little bit more egregious if we 5
had, for instance, like a wall or a floor, to say that 6
was going to be inoperable, because then you would 7
have to make an assumption in PRA space that that 8
falls, and whatever adjacent to that wall or structure 9
is impacted.
10 It's a little bit easier to do, for 11 example, for like a structural support, like the 12 emergency feedwater support.
13 (Audio interference.)
14 CHAIR HALNON: Continue on.
15 MR. FLOYD: Okay. For example, the one 16 support that was touching the containment enclosure 17 building, if they were not able through a calculation 18 to show that that support was adequate, then you would 19 just assume that that support fails and the equipment, 20 you know, the tubing that is supported by the support 21 has also failed. And you would toggle that failed in 22 the PRA.
23 And you would have to go through a 24 detailed risk analysis at that point to see if that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
79 impacts the emergency feedwater pump performance. You 1
would have to assume whatever the exposure time is, 2
probably go to a year at that point, because it's been 3
like that for a while. And you would have to look at 4
it under PRA space.
5 So, it's very much a case-by-case basis, 6
and when nothing is impacted and it's shown to be 7
operable, it's an easy screen to green. It's just, 8
through our Inspector Manual, Chapter 0609, you just, 9
the first box in there, when you ask the question 10 "Does it retain it's functionality/operability?"
11 screen to green.
12 CHAIR HALNON: Okay. It's a graded 13 approach. You keep on ratcheting up more and more 14 PRA-type language as you get closer to failure. And 15 to get to a white finding, which would be still low 16 safety significance -- I don't know if you still use 17 low to medium -- but it's still low safety 18 significance. It's a pretty high level of analysis 19 starting to go into it to determine the actual safety 20 impact?
21 MR. DAUN: At that point, anything above 22 green is going to take a detailed risk assessment.
23 So, you know, that can also input different 24 uncertainty calculations as well, but --
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80 CHAIR HALNON: So, my point is that it's 1
obviously very low safety significance. Otherwise, a 2
lot more PRA would have gone into it. So, your point, 3
well-taken.
4 MEMBER BIER: And, Greg, if I can expand 5
a little bit, since you did bring the PRA side in?
6 Nothing that I heard this morning of the 7
deficiencies that were identified as problems would 8
have even made it into a PRA. You know, you're 9
talking about what might be maybe, at worst, an 10 incipient failure. In other words, if you let this go 11 for 10 years without remediating it, it could 12 eventually be a failure that would affect your risk 13 analysis. But as long as you catch it and have a plan 14 to remediate it before it gets to that point, nobody 15 would redo their PRA based on what we saw today.
16 CHAIR HALNON: Okay. And back to Ron's 17 point, it's very slow progression at issue.
18 Other questions for Scott or Tom?
19 (No response.)
20 CHAIR HALNON: Okay. Bob, you're going to 21 be talking about what you saw from an oversight 22 perspective. So, this is their report card.
23 MEMBER MARTIN: Okay. So, for them, and 24 for everyone else, I came to this task guided, of 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
81 course, by the NRC Management Directive 8.13 on the 1
reactor oversight process. Now, that process is 2
involved and I'm certainly no expert in that. It has 3
several categories and a lot of details under each of 4
those categories.
5 I took a higher view of that, focused on 6
communication, technical
- adequacy, monitoring 7
retrofit, and management commitment.
8 And from the communication standpoint -
9 well, I'll take it one step further here. What I'm 10 looking for is this evidence-based compliance and 11 decisionmaking approach as it relates to safety. Ron, 12 or Members Ballinger and Harrington, of course, 13 highlighted the safety implications. I'll roll that 14 all up into, say, structural fragility, and then, 15 maybe the likelihood and consequence of structural 16 failures as their safety implication that is relevant 17 to ASR, in particular.
18 MR. BURKHART: Please hold. There's a 19 technical problem. Sorry.
20 (Whereupon, the above-entitled matter went 21 off the record at 3:37 p.m. and resumed at 3:38 p.m.)
22 CHAIR HALNON: Okay. Go on, Bob.
23 MEMBER MARTIN: Okay. No repeat here?
24 CHAIR HALNON: No.
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82 MEMBER MARTIN:
So, regarding 1
communication, of course, here we're interested in 2
both internal and external communication.
3 Travis, you gave us an excellent review of 4
your experience with that and what you've seen from 5
NextEra.
6 I appreciated the work that has been done 7
by the utility and preparing procedures, manuals, 8
related to what has to be done to address these 9
issues. I think they noted 15-16 --
10 MR. BURKHART: Hold on again. Sorry about 11 that.
12 (Whereupon, the above-entitled matter went 13 off the record at 3:38 p.m. and resumed at 3:41 p.m.)
14 CHAIR HALNON: All right. We'll go with 15 that.
16 So, microphone close; make it too loud.
17 You can't make it too loud.
18 MEMBER MARTIN: All right. So, I was 19 addressing the first of the five categories that I 20 identified here, broad categories under reactor 21 oversight process, the first being the communication.
22 We've heard a lot about that. As I noted, 23 Travis gave us an excellent review of that covering 24 the administrative documentation, the Corrective 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
83 Action Program and its implementation. Of course, 1
their engagement with NextEra, and then, the routine 2
meetings, which, of course, came up a little while 3
ago.
4 The second aspect, the technical adequacy 5
covering testing and analysis. Of course, we heard 6
from Members Ballinger and Harrington on the technical 7
side of things.
8 Of course, NextEra provided Ed Carley, who 9
really answered our questions, and not all of them 10 were soft balls, but he did an excellent job of 11 explaining some of just the normal processes that are 12 in place generally that have to be addressed. And 13 that will include some just characterization of the 14 condition of the concrete, those kind of testings, as 15 well as getting into the details of the testing they 16 had done at the University of Texas, and then, I guess 17 the independent testing at NIST.
18 From the standpoint of analysis, I 19 appreciated their graded approach to analysis using 20 conservative, and then, finer details or best-21 estimate-type analysis as necessary to meet criteria 22 that they established there.
23 We had the benefit from one of our 24 consultants, and again, could answer our tougher 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
84 questions.
1 We heard a lot from Nik on the structures 2
monitoring program. Obviously, he had several slides 3
there, and obviously, that was an important part of 4
our review here.
5 I did ask the question about what Rev 6
number their documents were, and when they said 18, I 7
felt like that's a reflection of the CAP program, 8
where you're submitting the tickets, making the 9
reports, and they get rolled up into these revisions.
10 Anything less than 18, I'd be worried, but, you know, 11 I was looking for a high number just for that reason.
12 The retrofit, I appreciate the walkdown, 13 and then, I appreciated the discussion we had briefly 14 on the impact to the updated FSAR, noting there were, 15 I guess, five specific updates that mostly related to 16 Code updates, and then, of course, the NRC's review of 17 that.
18 And then, lastly is looking at the 19 management commitment. Of course, we had their site 20 VP present, Dave Sluszka, and mentioned, of course, 21 the financial commitment, which seemed quite sizable.
22 I guess kind of my final impression is 23 just really with the now number of years here or front 24 time with what can only be described as first-of-a-25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
85 kind ASR mitigation program. The impression I get is 1
that they are now proactively identifying, assessing, 2
and resolving emergent issues related to ASR.
3 Do you want to add anything, Vicki?
4 MEMBER BIER: Sure. I think both on the 5
NRC side and the licensee side, I was generally 6
impressed just with the level of effort. I mean, you 7
folks have said that these issues cross your desk 8
pretty much literally every day. And the site folks, 9
where they have a team of about 20 people that are, 10 one way or another, devoted to this issue, that also 11 have daily meetings and discussions, and whatever.
12 So, the level of activity is extremely high.
13 And, you know, kind of coming back to the 14 point I made earlier, also, is just that nothing we 15 saw is the type of thing that would be responsible for 16 an accident in the next year, or whatever, imminently.
17 It's something that, yes, you have to keep your eye on 18 and make sure that it's mitigated if it develops, but 19 it looks like, first of all, no new areas, physical 20 areas of ASR recently. Most of them were identified 21 already, and it's not cropping up new across the site.
22 And there are adequate measures being taken to address 23 it where it does occur.
24 So,
- overall, I
thought it seemed 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
86 satisfactory, the way they were dealing with it.
1 I guess the one other point that I would 2
mention, which, again, kind of echos some of what Bob 3
just said, is that, at the site level in the early 4
years, when they were first learning about it, there 5
may have been some level of attitude of, well, we'll 6
hope this goes away, or whatever. But, by now, I 7
think they've learned that they have to live with it; 8
they have to own it and make it part of their day-to-9 day operations. So, that, yes, if somebody is working 10 on something else and sees a sign of some problem that 11 might be ASR-related, it gets flagged and captured for 12 somebody to look at. So, I thought that was fairly 13 positive.
14 CHAIR HALNON: Okay. Thank you.
15 My impression back when -- I've grown a 16 couple of fleets in my career. And when you take a 17 plant and you incorporate it into a fleet, there's an 18 essence of these programs that, first, it's the 19 implementation, which is a direct nexus to safety.
20 Then, there's the support function. It's the project 21 controls and the financial aspects.
22 And when one person is tasked with all 23 three of those, you can see that that's quite a burden 24 from the standpoint of making sure that all the pieces 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
87 fit together.
1 When you take those other two pieces, the 2
financial and the project controls, and you pass those 3
to an organization that's used to doing that, like 4
their fleet project controls group, then it leaves a 5
key focus of the site on the implementation piece, and 6
that's the key.
7 And that's what I saw today, was that, as 8
part of these findings, and also just the learning of 9
ASR in general, they've moved these other support 10 functions to the support organizations in the fleet, 11 which I thought was a very positive thing.
12 Now, back to you guys, it looks to me --
13 the knowledge management piece is important.
14 Especially as you guys continue to advance in your 15 careers, the mentoring, like the site is doing with a 16 couple of people, mentoring, and it appears you're 17 doing that also. And I think that's positive.
18 I think the outlook of inspections is 19 positive. But you've got to keep your thumbs on the 20 screw, right? And that's important.
21 And I think that's a key message of ours, 22 that we rely on you guys to make sure that that 23 implementation piece is solid. And right now, it 24 looks like it is to me at this point.
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88 Any other questions for Bob or Vicki?
1 (No response.)
2 CHAIR HALNON: Okay. I was going to give 3
an opportunity for our Chairman and our other member-4 at-large, do you have any concluding comments relative 5
to the visit that we had today that you wanted to 6
make?
7 Dave?
8 MEMBER PETTI: It's really nice when you 9
hear kind of the same thing twice or more. This 10 morning in the meeting what struck me was all the 11 margin that's built-in along the way, whether it be 12 the data, the analysis, which is sort of standard, 13 good engineering.
14 But, then, when you asked Nik about, "How 15 do you deal with uncertainty?" he gave the exact 16 answer that I would have given, which is that there's 17 margin. And so, you know, that struck me. I mean, 18 it's a really important piece that I don't think 19 people can fully appreciate. Engineers, that's what 20 we do for a living, right, when we design things. You 21 always are talking about margins and limits, and all 22 of that. It's very important.
23 CHAIR HALNON: Thanks, Dave.
24 Walt?
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89 MEMBER KIRCHNER: I'm good, and, yes, just 1
thank the staff of NextEra and, also, the Inspectors, 2
the NRC staff.
3 Like Dave, I was encouraged by what we saw 4
and heard from both the Applicant here, the operator, 5
and the staff when they looked at specific ASR-related 6
issues.
7 I came, in particular, looking at the CST 8
tank review and Inspection Report, and I came away 9
with, like Dave just said, some confidence that good, 10 sound engineering was being applied to the issues that 11 are in front of the Applicant and those that the NRC 12 is responsible for inspecting and compliance with the 13 AMPs.
14 So, that's my observation.
15 CHAIR HALNON: Thank you, Walt.
16 Okay. Before I open it up to public 17 comments, I want to make sure you guys from the Region 18 side, anything else you wanted to say? Anyone else 19 over here? Members?
20 (No response.)
21 CHAIR HALNON: Did Vesna ever join us?
22 MR. BURKHART: She did. She did, about 10 23 minutes after the meeting started.
24 CHAIR HALNON: Do I dare ask her if 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
90 there's a way she can talk on this thing? Have her 1
say it in the chat. Does she have any comments?
2 MR. BURKHART: She should have the ability 3
to speak.
4 Vesna? Your mic is open. We can't hear 5
you, Vesna.
6 CHAIR HALNON: What is she speaking into?
7 Is her speaker down?
8 MR. BURKHART: Vesna?
9 MEMBER DIMITRIJEVIC: Can you hear me?
10 CHAIR HALNON: We can hear you, yes.
11 MEMBER DIMITRIJEVIC: No. Okay. I'm 12 fine. I don't have any additional comments. I'm 13 fine. It's nice of you to give me the opportunity.
14 CHAIR HALNON: Thank you, Vesna. You did 15 help us make sure we can hear somebody online.
16 So, at this point, I'm going to open it up 17 for public comments.
18 In the room first, anyone from the room 19 that would like to come on up to the microphone and 20 state your name, affiliation, and we'll go enter it 21 into the record.
22 Oh, come on.
23 (Laughter.)
24 CHAIR HALNON: You can come up, Sarah.
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91 MS. ABRAMSON: Good afternoon. My name is 1
-- is this on?
2 MR. BURKHART: Yes, ma'am.
3 MS. ABRAMSON: Okay. My name is Sarah 4
Abramson. I'm Executive Director of the C-10 Research 5
and Education Foundation. I'm also a resident of 6
Stratham, New Hampshire. So, I don't live that far 7
from here. And I live within the 10-mile evacuation 8
pathway emergency planning zoning.
9 And I have been with C-10 for three years.
10 So, I came in the middle of this ASR situation. So, 11 I have done my best --
12 (Audio interference.)
13 MS. ABRAMSON: Shall I start over?
14 CHAIR HALNON: Yes.
15 MS. ABRAMSON: Hi. My name is Sarah 16 Abramson. I am Executive Director of the C-10 17 Research and Education Foundation.
18 I am also a resident of Stratham, New 19 Hampshire. So, I live nearby and within the 20 evacuation pathway emergency planning zone, a 10-mile 21 radius of Seabrook Station.
22 I've been with C-10 for three years, since 23 2022. So, I have tried to come up-to-date on this ASR 24 issue, which has, obviously, been around since its 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
92 discovery in 2010. And I've read the historical ACRS 1
transcripts and related letters.
2 After what I heard today and recent 3
information that I read in Inspection Reports, I have 4
some questions, well, some comments that I'd like to 5
get on the record.
6 One, I'd like to reiterate that continuity 7
is very important for this ASR issue. And I really 8
like seeing someone who's been with the ACRS since 9
this came to this body, and I'd like to see an 10 investment on the NRC side to keep that continuity 11 with the NRC staff as well.
12 I think it's also important to make clear 13 that there is no permanent remediation; i.e., even 14 when there is a physical modification, as Niklas Floyd 15 stated, the extensometer is still installed and it's 16 still monitored to measure the progression of ASR, and 17 the expansion can still exceed the allowable limits, 18 even in a structure that has had a physical 19 modification.
20 And there was an annual public safety 21 meeting a couple of years ago where the NRC staff 22 stated that there are some structures that are 23 trending to be beyond that allowable limit before the 24 2050 expiration date of the current operating license.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
93 So, I just want us all to be aware that we 1
might in the situation where some structures are 2
outside that allowable limit, and I'm confident in the 3
bodies here today in holding to the enforcement that 4
should be required at that time; i.e., additional 5
testing program, or whatever else that may entail.
6 I also want to mention the earthquake.
7 Obviously, that was something that a lot of members of 8
the public were aware because their house shook, and 9
there are a lot of questions about that. And I did 10 communicate with the Inspector staff at the plant that 11 day.
12 And I did want to note that this has been 13 something that C-10 has had a little bit of concern 14 about in the past, and I still continue to, even after 15 hearing what I've heard today; that NextEra asserted 16 that the two thresholds for taking an action in a 17 seismic event, the operating basis earthquake and the 18 safe shutdown earthquake levels, have not been changed 19 for Seabrook Station, even with the presence of ASR.
20 And so, it is just a question that's still 21 outstanding and I don't think that I, as a member of 22 the public, have gotten a satisfactory answer on the 23 technical justification of keeping those levels status 24 quo.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
94 And in the history of ASR, which we heard 1
from a couple of folks, C-10 was that advocacy group 2
that did bring that legal challenge. And those six 3
additional terms added to the license amendment that 4
was upheld by the Atomic Safety Licensing Board, one 5
example is that the frequency of monitoring in the 6
Tier 3 and some of the worst structures that are 7
showing the most severe progression of damage, that 8
was going to be 10 years before intervention. Every 9
10 years they were going to check. And now, it's six 10 months.
11 So, there is a big difference in what 12 different boards might find as technically acceptable.
13 And so, again, I think it speaks to the role of the 14 ACRS, of the ASLB, of these bodies full of technical 15 experts, in finding the gaps.
16 The plant is very clear on when physical 17 modifications are needed. That's very clear in the 18 regulations. But timeliness is one thing that is just 19 not defined, and we've seen a real variability in how 20 timely the corrective actions are on some of the ASR-21 related items like installing those missing 22 extensometers that appear to be a legacy issue, as 23 well as doing the initial ASR analyses on some newly 24 discovered -- well, at the time it was new, six years 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
95 ago discovered ASR areas in the reactor 1
containment.
2 It just seems like a long time to do 3
something that I think is a very high priority, but 4
I've heard, you know, the licensee gets to dictate 5
what in their Corrective Action Program is the 6
priority. That could entail costs. That could entail 7
effort. And I'd like to have a little more confidence 8
that the safety implication is the leading factor on 9
what gets the most timely remediation.
10 And it's also important to note that, when 11 an NRC Inspector embarks on an ASR-specific 12 inspection, they inspect a sample. And in the example 13 that they are inspecting 10 percent of the ASR areas 14 or 10 percent of the ASR procedures, if they're 15 finding two violations in one year, you know, you can 16 use some algebra to say, you know, maybe there's 20 17 violations happening.
What's reported in an 18 Inspection Report is not a complete illustration of 19 what may be occurring in terms of noncompliance.
20 And then, for a little context -- and we 21 talked about it a bit with some of the examples about 22 underpasses and things -- the Hampton Seawall is also 23 suffering from ASR and it's going to be completely 24 replaced. So, in the public vernacular, this is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
96 actually more common than maybe other parts of the 1
country. People know what ASR is. They see it in 2
their daily lives. They're aware of big federal 3
projects to fix it.
4 But I'm not hearing a lot of, like, 5
remediating structures. I'm hearing a lot about 6
replacing structures. And so, I think it would be 7
good to have just more information publicly available, 8
publicly consumable, so, you know, in more of, like, 9
a layperson-type format. So, we can understand what's 10 the difference between totally replacing the seawall 11 that has ASR and this nuclear power plant. Like what 12 makes it more robust? What makes it more able to 13 perform its original function?
14 Am I correct that anybody who's on the 15 Zoom cannot submit a comment on the record? Or can 16 they?
17 CHAIR HALNON: We are going to open it up 18 for comment.
19 MS. ABRAMSON: Then, I will let the person 20 who texted me make their own comments.
21 CHAIR HALNON: Yes. Okay.
22 MS. ABRAMSON: Thank you.
23 CHAIR HALNON: Thank you, Sarah.
24 Anybody else in the room?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
97 (No response.)
1 CHAIR HALNON: Okay. Then, as soon as I 2
get the thumbs-up, we'll open it up to the online 3
folks.
4 MR. BURKHART: So, this is Larry Burkhart 5
from the ACRS staff.
6 So, if you do want to make a comment and 7
you're on MS Teams, please raise your hand, like Dr.
8 Saouma already has.
9 So, with that, Dr. Saouma, you should be 10 able to unmute yourself and make your comments. So, 11 please do.
12 DR. SAOUMA: Yes. Thank you. On Slide 13 10, Item B, as in bravo, there is a mention of the 14 core bore studies. So, my question is, how important 15 is that equation which relates compressive strength to 16 elastic modulus? And, No. 2, what is the level of 17 uncertainty associated with it? That equation is 18 critical to determine the past expansion, which, by 19 the way, has not yet been reported, though you have 20 had ample opportunity to determine that, based on the 21 number of cores that you've extracted.
22 CHAIR HALNON: Okay. Those questions will 23 be entered into the transcript. We appreciate your 24 comment. Thank you.
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98 Anyone else online have any comments? If 1
you do, please raise your hand, and Larry Burkhart 2
will call on you.
3 MR. BURKHART: Yes. So far, I don't have 4
anybody who has raised their hand.
5 So, please, again, if you would like to 6
make a comment on MS Teams, please raise your hand.
7 No, there are no others I see.
8 CHAIR HALNON: Okay. Then, I will close 9
public comments at this time, and ask the members if 10 there are any final remarks or comments or questions 11 for each other or the staff.
12 (No response.)
13 CHAIR HALNON: Okay. Well, with that, I 14 do want to thank the members of the public and other 15 staff members that have come to this meeting. I want 16 to thank those online who took the time, and for the 17 member to travel this long distance.
18 We do a lot of travel and this is not a 19 portion of the country that we normally come. So, I 20 do appreciate all that.
21 Travis, if you could send our thanks back 22 again to the staff at NextEra for hosting us this 23 morning? It was an excellent exchange.
24 And we will consider all this information 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
99 as we go forward. At least at the present time, we 1
have it scheduled for the May 7th full Committee 2
meeting to discuss what our next steps are relative to 3
the information we have gotten.
4 So, with that, I'm going to adjourn the 5
meeting.
6 (Whereupon, the above-entitled matter went 7
off the record at 4:04 p.m.)
8 9
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Advisory Committee on Reactor Safeguards Operations Subcommittee Greg Halnon Vice Chairman, ACRS Advisory Committee on Reactor Safeguards (ACRS)
U.S. Nuclear Regulatory Commission 1
Subcommittee Meeting
- ACRS Introduction
- NRC Region 1 Inspection Oversight
- ACRS Scope of Review
- Materials Technical Issues and Mitigation
- Site Aging Management Program Performance
- Adequacy of Oversight Program 2
ACRS Purpose 3
ACRS provides independent technical advice to the Commission on matters that concern safety in support of the NRCs Mission NRC Mission Statement The NRC protects public health and safety and advances the nations common defense and security by enabling the safe and secure use and deployment of civilian nuclear energy technologies and radioactive materials through efficient and reliable licensing, oversight, and regulation for the benefit of society and the environment. (January 2025)
ACRS - History 4
1950 1960 1970 1980 1990 2000 2010 Chicago Critical Pile AEC is established Shippingport NRC is established Industrial Committee on Reactor Location Problems established The two Committees are combined into ACRS 1957 Amendment to the Atomic Energy Act of 1954 establishes the ACRS as a Statutory Committee Advising the AEC Enactment of the Energy Reorganization Act transferred the ACRS intact from AEC to NRC AEC forms Reactor Safeguard Committee 2020 ADVANCE Act passed
ACRS and the Federal Advisory Committee Act Openness and Candor Transparency Deliberations are conducted in public Letter Reports and Memorandums are publicly available 5
ACRS Responsibilities Independently reviews and reports to the Commission on safety studies and reactor facility license applications Independently advises the Commission on hazards of proposed or existing reactor facilities and the adequacy of proposed reactor safety standards Independently reviews and advises on matters referred to it by the Commission, including nuclear materials, radiation protection, and waste management Independently reviews and evaluates NRCs regulatory research program and reports to the Commission Upon request, reviews and advises on hazards of DOE nuclear activities and facilities 6
Role of the ACRS Safety Focused, Independent, and Objective
- Independent of NRC staff and reports directly to the Commission
- Consists of up to 15 members appointed by the Commission to 4-year terms (renewable)
- Consultants used to assist some reviews
- Broad, diverse set of academic, industry, and national laboratory technical expertise to enable integrated, multidisciplinary reviews
- Reviews structured to be cross-cutting and not duplicative of NRC staff work
- Reviews focus on safety, scientific and technical rigor, and completeness The ACRS only speaks through its published letter reports.
7
Current ACRS Subcommittees 8
Current ACRS Subcommittees 9
10 ACRS REVIEW PROCESS Committees Reviews and Recommendations Documents and Presentations Provided by Program Offices (NRR, NRO, RES, NMSS, etc.)
Documents and Presentations Provided by Nuclear Industry (Licensees, EPRI, NEI, etc.)
Documents and Presentations Provided by other Government Agencies (DOE, NIST, etc.)
Letter Reports Public Comments White Papers Technical Feedback During Both Full Committee and Subcommittee Meetings Meeting Summaries Site visits, hands-on reviews
Conduct of ACRS Review
- Subcommittee gathers information such as documents, presentations, discussions, site visits
- Subcommittee provides assessment and recommendation for Full Committee consideration
- Full Committee presentation, either summary or brief summary presentation of key issues, and collegial deliberation
- Preparation of Letter Report with conclusions and recommendations to Chairman or EDO
- The Committee speaks only through its Letter Reports (there is an opportunity for added comments) 11
Current ACRS Review Activities 12 Independent Advice to the Commission Licensing Reviews Regulatory Policies and Practices Operating Reactors Safety Oversight Safety Research Reviews New Reactors / Facilities
- Design Certification
- Early Site Permit
- Combined License
- Construction Permit
- Operating License
- New Facilities Operating Reactors
- License Amendments (Power Uprates, Topical Reports, etc.)
Rulemaking
- New/Revised Rules Guidance Documents
- Regulatory Guides
- Standard Review Plans
- Interim Staff Guidance
- Bulletins and Generic Letters Consideration of International Safety Approaches Significant Operating Events Generic Issues Reactor Oversight Process Assessment of Significant Ongoing Research Activities Triennial Reviews of NRCs Regulatory Research Program Nuclear Materials and Waste Waste Management Radiation Health Effects Health Physics
Operating Reactors Safety Oversight
- The ACRS has always been attentive to safety improvements in operation of nuclear power plants.
- Significant contribution toward resolution of many generic safety issues
- Deliberations regarding the role and effectiveness of the NRC Reactor Oversight Process (ROP) in monitoring plant performance 13
Summary
- Plant Operations Subcommittee monitors industry press, NRC reports, Operating Experience programs
- Significant issues are brought before the committee for information gathering and assessment
- Changing industry, regulatory, and technical landscape necessitates safety-oriented yet efficient reviews by ACRS
- Our approach is focused on safety significant issues in applications and regulatory matters
- ACRS reviews provide timely advice to the Commission in support of the NRCs mission 14
For More Information About ACRS 15 https://www.nrc.gov/about-nrc/regulatory/advisory/acrs.html
Alkali Silica Reaction 16
17 Note: Adapted from NRC Presentation, Seabrook Station Public Meeting: Safety Implications and Status of Alkali-Silica Reaction Condition in Safety Related Structures, 12/11/12 Alkali (in Cement)
Reacts with Silica (in Aggregate) and Water Silica Gel Forms Cracking Occurs As Gel Expands Alkali-Silica Reaction
18 Micro-cracking in the aggregate Visual signs of cracking on the surface of the concrete ASR Example Note: Adapted from NRC Presentation, Seabrook Alkali Silica Reaction (ASR) Information Briefing, 4/27/22
19 Safety Implications?
- ASR Progresses Slowly
- Limited to Hi Silica Aggregate
- Limited to Local Regions
- Long-Term Manageable
- No Indications of Rebar Degradation
- Visible Deformations
- Small Building Displacement
- Verification of Adequate Safety Margin Implementation of Monitoring Program Note: Adapted from NRC Presentation, Seabrook Station Public Meeting: Safety Implications and Status of Alkali-Silica Condition in Safety Rerated Structures, 12/11/12
Advisory Committee on Reactor Safeguards (ACRS)
Subcommittee Meeting Seabrook Alkali-Silica Reaction (ASR)
Update / Information Briefing Division of Operating Reactor Safety U.S. NRC Region I April 17, 2025
NRC Staff Presenters Nate Mentzer Senior Project Engineer Region I Niklas Floyd Senior Reactor Inspector Region I Travis Daun Senior Resident Inspector, Seabrook Region I 2
Agenda
- NRC Assessment Summary
- Alkali-Silica Reaction (ASR) Background
- Seabrook Aging Management
- NRC Inspection and Assessment of ASR
- Next Steps 3
NRC Assessment Summary
- NRC inspectors determined Seabrook structures remain capable of performing their safety functions as intended, including under limiting conditions
- NRC inspectors will continue to verify NextEra's performance to monitor and take corrective actions to maintain Seabrook structures
- NRC inspectors will continue to verify NextEras performance to meet ASR related license conditions 4
ASR Background
- ASR is a slow, expansive chemical reaction in hardened concrete which occurs in the presence of water, between the alkaline cement and reactive silica found in some aggregates
- The expansion can cause various material impacts 5
- 2009 - 2010: Testing confirmed the presence of ASR
- 2013 - 2016: Large-Scale Test Program
- 2014 - 2015: NRC identified bulk structural deformation in Seismic Category 1 structures
- March 2019: NRC approved and issued both the license amendment request (LAR) and renewed license
- Nov 2020: The LAR was challenged by a local advocacy group, but the licensing action was upheld (with modifications) by the Atomic Safety Licensing Board
Seabrook Aging Management 6
ASR Aging Management Program Building Deformation Aging Management Program Structures Monitoring Program (Demand)
Structural analyses Threshold limits based on load demand vs. capacity Monitoring:
Items from ASR program Crack measurements Seismic gaps Building dimensions (Capacity)
Maximum expansion based on the Large-Scale Test Program results Monitoring:
ASR grids (Crack Indexing and Pin-to-Pin)
Extensometers Equipment Impacted by Building Deformation Aging Management Program Monitoring:
Visual exam of equipment
Seabrook Aging Management Examples of Monitoring ASR at Seabrook:
7 Combined crack indexing (CCI) and pin-to-pin distance Seismic gap widths between buildings Crack gauges and widths Extensometers
Seabrook Aging Management 8
Examples of Modifications:
Fuel Storage Building vertical plates Mechanical Penetration Building corner braces and strong backs
NRC Inspection and Assessment of ASR
- NRC inspectors identified 5 findings of very low safety significance since 2020, and all have been addressed in NextEras corrective action program
- Inspection Report 2024004
- Scope: Re-baseline and re-evaluation of condensate storage tank enclosure; ASR expansion data review
- Results: No findings
- Inspection Report 2025001
- Scope: Corroboration study per ASR License Condition b and f; CIS reactor pit temperature data review; RHR vault rebar strain testing per ASR License Condition d and revised limits
- Results: In-progress 9
NRC Inspection and Assessment of ASR Seabrook ASR License Condition Status a
Assess expansion behavior to confirm it is comparable to the large-scale test program and check margin for future expansion.
First assessment completed.
Subsequent study every 10 years.
b Corroborate, using Seabrook field data, the concrete modulus to expansion correlation used to calculate pre-instrument through-thickness expansion.
Initial study completed.
Follow-up study by May 2035.
c Conduct a volumetric expansion check for control extensometers every six months.
Ongoing d
Develop a monitoring program to ensure that rebar failure or yielding does not occur, or is detected if it has already occurred, if the structural evaluations indicate rebar stress may exceed yield.
Ongoing e
If the ASR expansion rate significantly exceeds 0.2 mm/m (0.02%) through-thickness expansion per year, NextEra will perform an engineering evaluation focused on the continued suitability of the six-month monitoring interval.
Ongoing f
Each core extracted from Seabrook Unit 1 will be subjected to a petrographic analysis to detect internal microcracking and delamination.
Ongoing 10
Next Steps
- NRC will continue inspections under the Reactor Oversight Process that include NextEras ASR-related activities to:
11
- Bring structures into compliance with licensing basis
- Monitor ASR and building deformation
- Complete modifications (physical and/or reanalyze) on affected structures
- Validate thermal and ASR loads in CIS
- Implement ASR related license conditions
References 12 NRC Webpage on Concrete Degradation at Seabrook https://www.nrc.gov/reactors/operating/ops-experience/concrete-degradation.html NRC Webpage on Seabrook License Renewal https://www.nrc.gov/reactors/operating/licensing/renewal/applications.html Documents Available are at https://adams-search.nrc.gov/home:
ASR license amendment request
- NRC staff safety evaluation report: ML18204A291
- ACRS letter: ML18348A951 License renewal application
- NRC staff safety evaluation report: ML18362A370
- ACRS letter: ML18353A954 ASLB hearing decision
- Initial decision: ML20254A339
- Revised license conditions: ML20318A003
End of Staff Presentation 13
C-10 Research & Education Foundation l 11 Chestnut St., Amesbury, MA 01913 1
April 14, 2025 via electronic mail To:
U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Attn: Advisory Committee on Reactor Safeguards Lawrence Burkhart, Chief, Technical Support Branch, ACRS Cc:
Travis Daun, Senior Resident Inspector, Seabrook Station Nik Floyd, Senior Reactor Inspector Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety Raymond Lorson, Regional Administrator, Region I Mel Gray, Chief, Engineering Branch 1
Subject:
C-10 Research & Education Foundation pre-meeting questions and comments in advance of April 17, 2025 Advisory Committee on Reactor Safeguards (ACRS) subcommittee meeting regarding Alkali-Silica Reaction (ASR) at Seabrook Station.
At the September 4, 2024 ACRS meeting on the ASR issue at Seabrook, we appreciated the very thoughtful questions and concerns raised by the ACRS members.
We support the committees work and mandate from Congress to advise the Commissioners on technical matters such as this. We also appreciate the ACRS agreement to take C-10s comments and questions into consideration ahead of the planned site tour on April 17, 2025 to Seabrook Station wherein we understand an ACRS subcommittee will view in person the concrete degradation caused by ASR.
The following comments and questions are intended to highlight matters requiring clarification that have only recently come to C-10's attention. These questions are wholly new, and have not been presented by C-10 to the ACRS in the past.
- 1. Question: Which ACRS member is the designated subject matter expert for Alkali-silica reaction (ASR), or concrete degradation?
- 2. Question: Has the ACRS been provided with the details of all of Seabrook Stations Corrective Action Reports (CAR) related to ASR?
Background:
The periodic NRC Integrated Inspection Reports (IIR) show continued violations related to the licensees improper implementation of the ASR-related license requirements. C-10, like all members of the public, is not allowed access to any information in the licensees Corrective Action Program (CAP), with public records showing only the issues that rise to the level of a violation because they are reported in an inspection report. We understand from
C-10 Research & Education Foundation l 11 Chestnut St., Amesbury, MA 01913 2
the NRC inspectors that every licensees CAP includes violations documented in inspection reports as well as all of the other lower-level issues, including some related to ASR, that would only be accessible to an internal NRC body like the ACRS. We seek to ascertain whether you have reviewed this more detailed information. And if you have not done so, we believe it is important that this step is completed, in conjunction with the inspection on April 17th, in order for the ACRS to make its own independent judgment about the significance of the data.
- 3. Question: Has the NRC staff sufficiently explained to the ACRS the regulatory basis for approving NextEras newly applied method of re-baselining the CST enclosure?
Background:
Conservatism:
In the 2024 Q4 Integrated Inspection Report (ML25034A193):
NextEra performed a re-baseline where collected ASR monitoring data and trends from other monitoring locations are utilized to revise the conservative assumptions for ASR expansion in the original structural evaluation.
While the report mentions that conservative assumptions were initially established and subsequently increased to accommodate higher readings, the way conservatism has been assessed appears subjective and therefore introduces bias. Without a systematic and quantitative evaluation of the model's bias against independent experimental or field data (see below the conditions imposed by the LAR), the degree of conservatism cannot be reliably verified. A proper assessment requires formal validation, where model predictions are compared to reference measurements, and bias factors are calculated to quantify whether the model consistently errs on the safe side. Only through such a structured validation process can it be demonstrated that the thresholds remain conservative, appropriate, and scientifically defensible.
Finite Element Studies:
Despite the inspection reports extensive emphasis on analysis, none is relevant here: the issue concerns a factual physical measurement and its associated (now increased) threshold. No finite element analysis (extensively mentioned in the inspection report) can modify or rationalize the observed data.
C-10 Research & Education Foundation l 11 Chestnut St., Amesbury, MA 01913 3
Deviation From the License Amendment Request:
Per the license amendment request (ML19170A332):
NextEras review should include consideration of the uncertainty associated with extensometer readings and with in-plane expansion measurements. Assessments of expansion rate for the purpose of projecting future expansion should rely on trends comprised of multiple data points. If such projections indicate that the limits may be exceeded prior to the next periodic check, NextEra should include consideration of the uncertainty associated with extensometer readings and with in-plane expansion measurements. If such projections indicate that the limits may be exceeded prior to the next periodic check, then NextEra should further investigate the location(s) in question or develop contingency plans for extending the expansion limit (e.g., supplemental testing).
There is no indication that all the necessary conditions for re-baselining have been satisfied. In particular:
- 1. Uncertainty in Measurements: No evaluation of the uncertainty associated with the extensometer readings has been presented.
Physical measurements must be accompanied by a quantified margin of error to allow for proper interpretation. Without explicitly accounting for measurement uncertainty, the outcome is inherently biased and cannot be reliably interpreted.
- 2. Investigation and Contingency Planning: Despite the guideline requirements, there is no evidence that NextEra has investigated the affected location(s) where thresholds could be exceeded, nor have contingency plans such as supplemental testing been developed.
- 3. Supplemental Testing: There is no indication that additional testing is being planned or performed to substantiate the revised expansion limits. Without supplemental data, the re-baselining lacks the scientific rigor needed to ensure continued structural safety.
In the absence of these critical evaluations, an attempt at re-baselining cannot be considered scientifically justified.
Deviation from NRC Regulatory Guide 1.207, and
Conclusion:
The NRC Regulatory Guide 1.207 and 10 CFR 50.59 Methods or solutions that differ from those described in this regulatory guide may be deemed acceptable if sufficient basis and information is provided for the NRC staff to
C-10 Research & Education Foundation l 11 Chestnut St., Amesbury, MA 01913 4
verify that the proposed alternative demonstrates compliance with the appropriate NRC regulations.
It is useful for the NRC to clarify to the ACRS if the prerequisites for re-baselining had been satisfied prior to the implementation of the re-baselining, such as the evidence and necessary supporting documentation that NextEra would have been required to provide to the NRC. Under NRC Regulatory Guide 1.207 and 10 CFR 50.59, deviations from approved methods must be supported by sufficient information to allow the NRC to independently verify compliance. NRC staff should provide clarity to the ACRS explaining if such a verification took place.
While we understand that re-baselining is permitted, it is not clear if the procedures that NextEra used included all that is required, such as supplemental testing, without which re-baselining is procedurally improper and scientifically unjustified.
- 4. Question: Is the ACRS aware of action taken by the licensee to seek, review, and apply as necessary, external scientific findings related to ASR in nuclear power plant concrete structures, in order to be compliant with NUREG-0737?
Background:
NUREG-0737: Clarification of TMI Action Plan Requirements (ML102560051) requires nuclear reactor licensees to report on how they seek and apply new, best available scientific information as part of their Operating Experience (OE) program. During Seabrook Stations license renewal, NextEra wrote in a 2018 document to the NRC that other groups were in the process of performing analogous studies on ASR in concrete structures at nuclear power plants, and that certain preliminary findings from those studies had produced similar results to the LSTP, referring to NextEras own Large Scale Testing Program (ML18348A951). Since then, final results of those specific studies mentioned by NextEra have been published, such as a 2021 report on a study by the National Institute of Standards and Technology (NIST) Structural Performance of Nuclear Power Plant Concrete Structures Affected by Alkali-Silica Reaction (ASR) which contains additional and more comprehensive findings that could be applicable to the ASR phenomenon at Seabrook Station.
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[1] NRC. (2025) SEABROOK STATION - INTEGRATED INSPECTION REPORT 05000443/2024004. https://www.nrc.gov/docs/ML2503/ML25034A193.pdf
[2] NRC. SEABROOK STATION UNIT 1 LICENSE RENEWAL APPLICATION: REVIEW OF LICENSEE PROGRAM ADDRESSING ALKALI-SILICA REACTION. Page 4.
https://www.nrc.gov/docs/ML1834/ML18348A951.pdf
[3] NRC. (1980). Clarification of TMI Action Plan Requirements.
https://www.nrc.gov/docs/ML1025/ML102560051.pdf
[4] NextEra. (2019). MPR-4273, Rev. 1, Seabrook Station - Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction (July 2016) (Non-proprietary version) (Enclosure 5 to Letter SBK-18072).
https://www.nrc.gov/docs/ML1917/ML19170A332.pdf Page B-2.
[5] Weigand, J., Sadek, F., Thonstad, T., Marcu, S., Villegas, R., Phan, L. and Pintar, A.
(2021), Structural Performance of Nuclear Power Plant Concrete Structures Affected by Alkali-Silica Reaction (ASR). Task 3: Assessing Cyclic Performance of ASR-Affected Concrete Shear Walls, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932991 (Accessed April 10, 2025)