ML18348B117
| ML18348B117 | |
| Person / Time | |
|---|---|
| Issue date: | 10/31/2018 |
| From: | Kent Howard Advisory Committee on Reactor Safeguards |
| To: | |
| Howard K | |
| References | |
| NRC-3949 | |
| Download: ML18348B117 (395) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION Title: Advisory Committee on Reactor Safeguards License Renewal Subcommittee Open Session Docket Number: (n/a)
Location: Rockville, Maryland Date: Wednesday, October 31, 2018 Work Order No.: NRC-3949 Pages 1- NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005
-3701 www.nealrgross.com 1 1 2 3 DISCLAIMER 4 5 6 UNITED STATES NUCLEAR REGULATORY COMMISSION'S 7 ADVISORY COMMITTE E 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 t ranscript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
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-3701 (202) 234-4433 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
+ + + + + ADVISORY COMMITTEE ON REACTOR SAFEGUARDS (ACRS) + + + + + LICENSE RENEWAL SUBCOMMITTEE
+ + + + + OPEN SESSION
+ + + + + WEDNESDAY OCTOBER 31, 2018
+ + + + + ROCKVILLE, MARYLAND + + + + + The Subcommittee met at the Nuclear Regulatory Commission, Three White Flint North, Room 1C3 & 1C5, 11601 Landsdown Street, at 8:30 a.m., Gordon R. Skillman, Chairman, presiding.
COMMITTEE MEMBERS:
GORDON R. SKILLMAN, Chairman MICHAEL L. CORRADINI, Member RONALD G. BALLINGER, Member DENNIS C. BLEY, Member*
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-3701 (202) 234-4433 CHARLES H. BROWN, JR., Member VESNA B. DIMITRIJEVIC, Member WALTER KIRCHNER, Member JOSE MARCH
-LEUBA, Member JOY L. REMPE, Member PETER RICCARDELLA, Member ACRS CONSULTANT:
STEPHEN SCHULTZ DESIGNATED FEDERAL OFFICIAL:
- Present via telephone
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-3701 (202) 234-4433 AGENDA Opening Remarks
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...4 Member Comments
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..10 Statement from the Deputy Director of the Division of Material and License Renewal
.........14 Applicant Remarks
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17 Overview and Timeline for ASR Issue at Seabrook
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.19 ASR Presentation, Load Fact ors, Methodology, Fiel d Data, Structural Evaluation
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65 NRC Review of ASR
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198 Public Comments
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.. 289 Adjournment
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-3701 (202) 234-4433 P R O C E E D I N G S 1 8:30 a.m. 2 CHAIRMAN SKILLMAN: Ladies and gentlemen, 3 good morning. This meeting will now come to order.
4 This is a meeting of the ACRS's Plant License Renewal 5 Subcommittee. I am Gordon Skillman. I'm Chairman of 6 the ACRS License Renewal Subcommittee.
7 ACRS members in attendance are Dr. Ronald 8 Ballinger, Dr. Peter Riccardella, Dr. Walter Kirchner, 9 Dr. Joy Rempe, Dr. Michael Corradini, Dr. Jose 10 March-Leuba, Dr. Vesna Dimitrijevic, and Dr. Dennis 11 Bley by phone.
12 Our colleague, Mr. Charlie Brown, will 13 attend later. We welcome Dr. Stephen Schultz as our 14 consultant on this topic, and Mr. Kent Howard of the 15 ACRS staff is the designated federal official for this 16 meeting. 17 NextEra, the licensee for Seabrook 18 station, is following the required protocol for 19 requesting a license renewal for 20 years for the 20 Seabrook Station.
21 This special meeting is convened to provide 22 focus on one unique topic effecting license renewal 23 of this nuclear power plant, and that topic is 24 alkali-silica reaction on structures, systems, and 25 5 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 components within the scope of the license renewal at 1 the Seabrook Station.
2 Because of the critical nature of this 3 topic, the ACRS considered this independent meeting 4 appropriate and important to enable stakeholder, 5 licensee, and staff part icipation.
6 In this Subcommittee meeting, we expect 7 the staff and NextEra to brief the Subcommittee on the 8 status of the alkali
-silica reaction issue at Seabrook.
9 The Subcommittee will gather information, analyze 10 relevant issues, formulate a proposed posit ion for 11 deliberation for deliberation for the full committee 12 if needed.
13 As we begin, I would like to emphasize 14 several points relating to this specific meeting. One 15 of Seabrook Station's required aging management 16 programs addresses structures, systems, an d 17 components.
18 The AMP, Aging Management Program, that 19 addresses SSCs, structures, systems, and components, 20 must address the suitability of the SSC for the 21 mechanical loading for the period of extended 22 operation.
23 The alkali
-silic a reaction discovered at 24 Seabrook obligates determining its impact on those SSCs 25 6 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 within the scope of license renewal Seabrook.
1 The ASR imposes structural loadings that 2 are different than those originally addressed in 3 Seabrook's operating license. NextEra is required to 4 formally address those different structural loadings 5 through a license amendment request.
6 NextEra has submitted a license amendment 7 request to address the different loadings. The license 8 amendment request is based on research and analysis 9 and data intended to demonstrate the acceptability of 10 ASR in those SSCs that are required both for present 11 and for future plant operation.
12 This meeting is focused on determining 13 whether the SSCs affected by ASR and addressed by the 14 AMP and the license amend ment request are acceptable 15 for the requested period of extended operation that 16 NextEra has requested in their license renewal 17 application for Seabrook.
18 The ACRS was established by statute and 19 is governed by the Federal Advisory Committee Act, FACA.
20 That means that the committee can only speak through 21 its published letter reports. Let me say that again 22 so that it's clear in everyone's mind. That means that 23 the committee can only speak through its published 24 letter reports.
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-3701 (202) 234-4433 This m eeting, a Subcommittee meeting, 1 enables the members to express their comments and 2 concerns, and those comments may or may not find their 3 way into the final letter of report. That means we 4 speak as individuals.
5 The ACRS reviews and advises the Commission 6 with regard to licensing and operation of production 7 and utilization facilities and related safety issues, 8 the adequacy of proposed reactor safety standards, 9 technical and policy issues related to the licensing 10 of evolutionary and passive plant designs, and other 11 matters referred to it by the Commission.
12 The ACRS section of the U.S. NRC public 13 website provides our charter, bylaws, letter reports, 14 and full transcripts of all Subcommittee meetings, 15 including slides presented at the meetings.
16 The rules for part icipation in today's 17 meeting were announced in the Federal Register. The 18 meeting was announced as open, but here it is. Portions 19 may be closed as needed to protect information 20 proprietary to NextEra or its vendors pursuant to 5 21 USC 552BC4.
22 We have, I repeat, we have received written 23 comments and requests for time to make oral statements 24 from members of the public during today's meeting.
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-3701 (202) 234-4433 A transcript of the meeting is being kept 1 and will be made available as stated in the Federal 2 Register notice. Therefore, we request that 3 participants in this meeting please use the microphones 4 located throughout the meeting room when addressing 5 the Subcommittee.
6 Participants are requested for first 7 identify themselves and speak wit h clarity and volume 8 so that they can be readily heard.
9 A telephone bridge line has been 10 established for this meeting. We have several members 11 of the public, one ACRS member, and perhaps others from 12 the public listening in on the public bridge line.
13 Thi s public line will be closed during the 14 closed section of the meeting and will be reopened 15 during the open session. We will close the public line 16 as necessary if that is required.
17 To preclude interruption of the meeting, 18 we ask that you please mute your i ndividual lines during 19 the presentations, and for those in the room, we request 20 that you please silence all your phones and electronic 21 devices. 22 Before turning the meeting over to Joe 23 Donoghue of DMLR, and this is different for ACRS, I 24 want to provide opportunity for ACRS members to express 25 9 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 their expectations for this meeting. We don't normally 1 do this.
2 My concern is very often the ACRS is seen 3 as a group of individuals who are perhaps not too willing 4 to engage or perhaps not express their thoughts. Since 5 this meeting is different, I want to give the members 6 an opportunity to provide comment before we begin so 7 that NextEra and the staff can hear , if you will, how 8 the ACRS thinks.
9 I will begin by stating that I am interested 10 in both the staff's and licensee's clear statements 11 that communicates their understanding of the 12 seriousness of the ASR issue at Seabrook, clarity 13 regarding the scope of the s tructures, systems, and 14 components affected by ASR, clarity regarding the 15 extent of condition resolution and research of this 16 phenomenon, demonstration of the discipline related 17 to understanding the as
-found state and of the 18 progression of the ASR phenomen on, and the thoroughness 19 of the licensee's plans, actions, commitments, and 20 programs to fully and comprehensively address ASR.
21 I invite my colleagues to offer their 22 opening comments. I will begin by asking Dr.
23 Dimitrijevic.
24 MEMBER DIMITRIJEVIC: So this is my first 25 10 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 meeting on this issue, so my goal of this thing is to 1 see that we have a full understanding of the issue and 2 status. So I have a very small expectation just to 3 get completely familiar and understanding of the issue, 4 okay. 5 CHAIRMAN SKILLMAN: Thank you, Vesna.
6 Dr. Corradini?
7 MEMBER CORRADINI: I also am trying to 8 learn about the issue, so my only comment is I think 9 the background information we've gotten is quite 10 comprehensive, so I think that will help.
11 CHAIRMAN SKILLMAN: Thank you, Mike. Dr.
12 Rempe? 13 MEMBER REMPE: Thank you, Dick. I, in 14 reading through the material, was very interested in 15 why there was such a long time between the 2010, 2009 16 initial observation of ASR and then the time frame 17 before another indication of it was identified in 2014.
18 19 ASR is a known phenomena in other 20 industries and applications, and I am interested in 21 that lag because I want to understand that you're not 22 only monitoring the ASR identified structures, but 23 other structures that might be susceptible, okay?
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-3701 (202) 234-4433 CHAIRMAN SKILLMAN: Thank you, Joy. Dr.
1 Riccardella?
2 MEMBER RICCARDELLA: Yes, thank you, Dick.
3 I'm a mechanical engineer with a background in 4 structure strength and materials, structural analysis, 5 and probably the closest thing we have on this committee 6 to a structural engineer. I've spent a lot of times 7 in the last couple of weeks reviewing the background 8 information, which I found to be a very, very impressive 9 program and comprehensive.
10 I have some qu estions, and I guess my goal 11 for this meeting is to get those questions answered 12 and get all of the information we need for our full 13 committee deliberations.
14 CHAIRMAN SKILLMAN: Thank you, Pete. Dr.
15 Kirchner? 16 MEMBER KIRCHNER: Thank you, Dick. My 17 particular interest in this meeting is to see how the 18 test program that was conducted bounds the problem based 19 on the condition assessment and project impact of this 20 ASR over the applicant's, you know, the extended license 21 period. Thank you.
22 CHAIRMAN SKILLMAN: Thank you, Walt. Dr.
23 March-Leuba? 24 MEMBER MARCH
-LEUBA: As opposed to my 25 12 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 members, I want to start by apologizing for two things.
1 First, it will take a little while to understand my 2 accent, so I will try to speak slowly into the 3 microphone, and second, I am not an expert on this 4 whatsoever.
5 I mean, ASR, my extent of ASR knowledge 6 is wherever there's a snow forecast, I put the snow 7 on my driveway, and when the snow is away, the driveway's 8 kind of chipped, so tha t's what I know.
9 So considering the questions, I wanted to 10 apologize, but the questions I will ask you during the 11 presentation, consider me an uninformed member of the 12 public and I will try to kind of inform the public 13 through my questions.
14 CHAIRMAN SKILLMAN: Thank you, Jose. Dr.
15 Ballinger?
16 MEMBER BALLINGER: Thank you, Dick. I 17 really can't add anything to what everybody else has 18 said except for the fact that I live in the EPZ for 19 Seabrook. More importantly, the Airfield Café and the 20 Max BMW motor cycle place is in the EPZ, so I have a 21 very keen interest in what's going on.
22 My area is corrosion and materials, and 23 I've actually done work related to ASR, so my 24 expectation is to understand that you folks understand 25 13 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the process and what's going on, and in particular, 1 what Walt has to say, how the testing has bounded the 2 conditions at Seabrook.
3 CHAIRMAN SKILLMAN: Thank you, Ron. Dr.
4 Schultz? 5 MR. SCHULTZ: My experience is in 6 technical support for supporting operating reactors 7 as a licensee, and I'm sure the Committee wants to 8 develop today a full understanding of the requirements 9 of the ongoing and forward
-looking plan and program 10 for addressing ASR.
11 How has it been implemented for the current 12 operation of the plant? What mod ifications are 13 required in the near term as a result of the license 14 amendment commitments by the licensee? What if 15 anything in the current program is still in flux?
16 And I want to, we want to assure that the 17 applicant, the Committee, and the staff wil l be certain 18 that the program for addressing ASR is fully in place 19 to support the application for license renewal.
20 CHAIRMAN SKILLMAN: Thank you, Steve.
21 Dr. Bley, may I ask you, please, to offer any comment 22 or expectation you might have, sir?
23 MEMBER BLEY: No, thank you, Dick. I have 24 nothing additional to add, but I am interested in how 25 14 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the test results have proceeded. Thanks.
1 CHAIRMAN SKILLMAN: Thank you, Dennis.
2 With that, I'm going to turn the meeting over to Joe 3 Donoghue, the Deputy Director of the Division of 4 Material and License Renewal. Joe, welcome, and thank 5 you. Please proceed.
6 MR. DONOGHUE: Good morning. Thank you, 7 Chairman Skillman, members of the ACRS License Renewal 8 Subcommittee, and other ACRS members in attend ance. 9 Yes, I'm Joe Donoghue. I'm the Deputy Director of the 10 Division of Materials and License Renewal.
11 We thank the Subcommittee for the 12 opportunity to present an overview of the NRC's 13 activities associated with the review of the 14 alkali-silica reaction or ASR effecting concrete 15 structures at Seabrook Station Unit 1, as well as the 16 results of the staff's review of the applicant's 17 methodology for assessing structures impacted by ASR 18 that was submitted in a license amendment request, and 19 the staff's review of the aging management programs 20 that are credited for addressing ASR in their license 21 renewal application.
22 I'll just add that there's two separate 23 actions that are affected by this, the license amendment 24 request as well as the license renewal. They depend 25 15 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 on the same methodology and the license renewal depends 1 on, it involves a program that's going to, the aging 2 management program that's going to address it.
3 The NRC has spent considerable time and 4 effort on the ASR issue to ensure t hat it was 5 appropriately addressed for operability as part of the 6 current licensing basis and in the aging management 7 program's credit for the license renewal.
8 Just to highlight the extent of the effort, 9 we had site resident inspectors performing regular 10 inspections to assess operability. We had Region I 11 inspection staff who were supported by headquarters' 12 technical staff conducting problem identification and 13 resolution inspections onsite, and we did inspections 14 at the testing site.
15 We had senior structural engineers from 16 the Division of Engineering assessing the aging 17 management programs for ASR, the structural assessment 18 methodology, and the large
-scale testing that was 19 conducted at Ferguson Structural Engineering Lab at 20 the University of Texas. They were also supported by 21 structural engineers from Brookhaven National Lab.
22 The staff also had a team of reviewers and 23 experts that we established back in 2012 to coordinate 24 all of our activities.
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-3701 (202) 234-4433 In July 2012, the staff presented the 1 sa fety evaluation report with open items to the ACRS 2 License Renewal Subcommittee, and of those open items 3 that existed at the time, the one associated with aging 4 management for ASR dominated the discussion.
5 Today, the staff will present its review 6 of the en hanced and newly developed aging management 7 programs that address ASR that are the basis for the 8 SAR, and that we think resolve this open item. We will 9 present the complete SER and address the remaining open 10 items in a meeting in a couple of weeks to the 11 Subcommittee.
12 The project manager for the Seabrook 13 license renewal safety review and who will lead us 14 through the presentation is Butch Burton seated 15 opposite me in the room.
16 Part of the management team that are here 17 with me today are Eric Oesterle next to me, Chief of 18 the Projects Branch in our division, Kamal Manoly who 19 is Senior Level Advisor for Structural Mechanics from 20 the Division of Engineering, and other division and 21 NRR office technical experts and managers.
22 We also have in the audience and on the 23 phone other staff who supported the review, as well 24 as Region I staff who performed the facility inspections 25 17 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and supported the license renewal reviews, and you'll 1 be hearing from one of them in the presentations later 2 today. 3 We look forward to a productive discussion 4 with the ACRS Subcommittee, and as always, we will 5 address any questions on this review that you may have.
6 And at this time, I'd like to turn the presentation 7 to NextEra and their Regional Vice President for the 8 Northern Region, Mr. Eric McCartney, to introduce his 9 team. 10 MR. McCARTNEY: Thank you, Mr. Donoghue.
11 As he said, my name is Eric McCartney and I've been 12 the Regional Vice President for NextEra Energy 13 responsible for the Seabrook Station, Point B Station, 14 and Duane Arnold Station for the past year.
15 I've been in the commercial industry for 16 33 years now. I started my career as an unlicensed 17 operator and I have served as the plant manager or site 18 vice president at five different stations i n the course 19 of that career. I was a senior reactor operator, 20 licensed operator at the Harris Nuclear Plant outside 21 of Raleigh, North Carolina.
22 We're pleased to have the opportunity to 23 discuss our structures monitoring program specifically 24 as it relates to alkali
-silica reaction with the 25 18 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Committee today.
1 NextEra has expended a tremendous amount 2 of time and resources to develop a clear understand ing 3 of this issue and develop a comprehensive structures 4 monitoring program that provides us assurance that we 5 can operate the plant safely and reliably not only for 6 the current license, but for the extended license that 7 we are requesting.
8 We recognize tha t this condition is a life 9 of the plant condition, and as a corporation, we remain 10 committed to engage in anything and all activities we 11 need to do to ensure that we operate this plant with 12 the safety margins that it's designed to operate with.
13 We have worked diligently with industry 14 leaders to ensure that we gain any expertise that we 15 may lack at our facility. We have engaged with the 16 folks that we need to, to make sure that we clearly 17 understanding this. Many of them are here today that 18 will help in the discussion.
19 We also recognize the obligation that we 20 have to the industry to share what we've learned as 21 we go forward with this process. We remain engaged 22 with INPO through our membership.
23 We continue to work with NEI, and EPRI , 24 and other industry groups to share everything that we 25 19 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 learned to ensure that the industry and other facilities 1 in other industries can gain the knowledge that we've 2 gained as we've worked through this process.
3 Today, we'll talk about our large
-scale 4 testing program. We'll talk about the development of 5 the methodologies to monitor the loads, and we'll talk 6 about our structures monitoring program, and provide 7 a comprehensive discussion of both of those, and I 8 believe we'll answer all of the questions and c oncerns 9 that you articulated as you went through your questions.
10 If we could go to our slide?
11 MR. BURTON: Good morning. As Joe said, 12 my name is Butch Burton. I'm the project manager for 13 the NRC staff safety review of the license renewal 14 application for Seabrook station Unit 1.
15 As was already mentioned, we're here today 16 to discuss the staff's closure of the open item related 17 to the alkali
-silica reaction known as ASR related to 18 the Seabrook license renewal application.
19 The closure of this open item is documented 20 in the staff's safety evaluation report for the license 21 renewal application and is supported by the staff's 22 safety evaluation on a related license amendment 23 request. Both of these documents were issued on 24 September 18, 2018, and provided to the Subcommittee.
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-3701 (202) 234-4433 We'd like to begin this meeting by 1 providing you with an overview and timeline of the NRC's 2 activities related to ASR at Seabrook. We'll then turn 3 the meeting over to representatives from NextEra Energy 4 Seabrook, which is the licensee for Seabrook, who will 5 discuss their activities on this project.
6 Following the NextEra presentation, the 7 staff will discuss its review, audit, and inspection 8 activities associated with ASR at Seabrook, and we'll 9 discuss the basis for its c losure of the ASR open item 10 in the SER.
11 As we stated, portions of this meeting will 12 be closed to the public. The staff has not prepared 13 presentations for the closed portion of the meeting, 14 but will be available to answer any questi ons from the 15 Subcommittee during the closed portion of the meeting.
16 Seabrook is a single
-unit Westinghouse 17 four-loop pressurized water reactor located just south 18 of Portsmouth, New Hampshire. Its 40
-year operating 19 licensed was issued on March 15, 1990, an d the unit 20 began commercial operation on August 19, 1990. NextEra 21 is the principal owner and operator of the unit.
22 On May 25, 2010, NextEra submitted a 23 license renewal application requesting renewal of its 24 operating license to allow operation for 20 years beyond 25 21 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the expiration date of its current license. Issuing 1 a renewed license would allow the plant to operate 2 through March 15, 2050.
3 In 2009, NextEra identified pattern 4 cracking in sections of walls and certain below grade 5 structures at Seabrook. In 20 10, NextEra confirmed 6 that this cracking was due to ASR. In order to address 7 this ASR issue, NextEra pursued two licensing actions.
8 9 It amended its existing license renewal 10 application to include activities to manage aging 11 resulting from ASR and it submitted a license amendment 12 request to address the nonconforming condition with 13 its current license resulting from the effects of ASR.
14 As you can see, these actions were 15 addressed along two parallel tracks. The upper track 16 shows that NextEra submitted an amendment to its license 17 renewal application and shows the staff's review and 18 the issuance of its review findings in the safety 19 evaluation report.
20 The lower track shows that NextEra 21 submitted a license amendment request to address ASR 22 in current licensing space, and shows the staff's review 23 and the issuance of its review findings as the final 24 safety evaluation.
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-3701 (202) 234-4433 As shown, the identification of ASR at 1 Seabrook led to an immediate impact on the license 2 renewal application review schedule a nd a prolonged 3 time period of NRC oversight activities to fully 4 understand the issue. The NRC's activities will be 5 discussed in more detail during our presentation this 6 afternoon.
7 Before I turn it over to NextEra, I did 8 want to ree mphasize what Chairman Skillman mentioned 9 before, that portion of NextEra's presentation will 10 be closed. During that time, we will ask members of 11 the public to leave the room and we will also close 12 the public bridge line. After the closed portion of 13 the meeting is completed, we'll bring members of the 14 public back in and reopen the public bridge line, and 15 they'll let us know when it's appropriate to do that.
16 Now I'll ask representatives from NextEra 17 to discuss their activities to address ASR at Seabrook.
18 MEMBER MARCH
-LEUBA: Just a question and 19 first I'd like to inform you that we, the members, we 20 ask a lot of questions and we interrupt a lot, so you 21 know that. So I'm not sure if you are the correct person 22 to ask this, but is this a program which is speci fic 23 to Seabrook or is this a more generic issue? Is the 24 staff considering it in other plants?
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-3701 (202) 234-4433 And I'm thinking the ASR, the S stands for 1 silica, and most concrete is done with limestone. Is 2 that the answer? Is Seabrook the only plant that used 3 silica hydrates? 4 MR. BURTON: I can say that as far as the 5 nuclear industry, I believe, and correct me if I'm 6 wrong, I believe that Seabrook is the only nuclear plant 7 that has found this problem, although my understanding 8 is that it is an issue in other areas such as, I guess, 9 transportation, but we do have some of our technical 10 folks here. I don't know the extent to which it applies 11 to other things beyond what we're seen. I don't know 12 if - 13 MEMBER MARCH
-LEUBA: So the other question 14 is you don't believe it's a generic issue, but was there 15 a generic letter issued to make sure that every other 16 plant was aware of the problem?
17 MR. DONOGHUE: No, this is Joe Donoghue.
18 No, we didn't issue a generic letter on this, and this 19 is a plant specific program that was put together.
20 There is continuing research that I think you're going 21 to hear about today. I think in his opening remarks, 22 Mr. McCartney mentioned their connection with INPO, 23 so the industry is aware of the issue, but this is
- 24 My understanding, and I think you're going 25 24 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 to hear this from the staff's presentation, this is 1 the first plant that observed ASR and this is the only 2 plant that I know of that has experienced it to the 3 extent that it could affect operability, and that's 4 what we're a ddressing here, so other plants have not 5 experienced it to that extent.
6 MEMBER MARCH
-LEUBA: I'm thinking from the 7 point of view of physics, not
- I mean, you need two 8 things for this to happen. You need to be close to 9 the sea to have salty water in your basement and have 10 used concrete that is segregated with granite.
11 MR. DONOGHUE: So Angie, one of our experts 12 who you're going to hear from later today, can add to 13 my, to our answers.
14 MS. BUFORD: Sure, when the ASR issue was 15 discove red at Seabrook, the NRC staff did issue an 16 information notice which didn't require licensees to 17 provide the NRC with written feedback, but it did 18 require that licensees consider the potential for ASR, 19 and so per the process for dispositioning information 20 notices, that goes into the corrective action program, 21 and then our resident inspectors inspect to make sure 22 that the licensees have adequately considered it.
23 MEMBER MARCH
-LEUBA: Excellent, so you 24 would have held the ball and considered it on a generic 25 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 ba sis and discounted it. Thank you.
1 CHAIRMAN SKILLMAN: So NextEra is up.
2 Yes, sir? 3 MR. McCARTNEY: Thank you, Mr. Chairman.
4 So I have with me today Mr. Mike Collins. He's our 5 engineering director at the Seabrook Station. Mr. Ken 6 Brown is our licensing manager. Mr. Ed Carley, Ed is 7 our program manager for license renewal. And behind 8 you is Ms. Jackie Hulbert, and Jackie is our program 9 engineer for the ASR program.
10 Before I turn it over to the team for some 11 technical discussion, I'd like to bring your attention 12 to a little about the nuclear excellence model at 13 NextEra Energy.
14 This is a model of how we use to govern 15 our operation within our fleet. It's been in our 16 protocol since 2008. It's based on a set of core 17 principles and values that have never changed. They've 18 been the same since we introduced the model.
19 You'll see at the first top value on the left, 20 it's the, we conduct all activities with a deep respect 21 for nuclear safety. This is the foundation of how we 22 operate our fleet and our enterprise.
23 We also focus very heavily on being a 24 self-improving culture and a learning organization, 25 26 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and you'll see through our discussion, everything that 1 we talk about in our structures monitoring program is 2 subject to our appendix B corrective action program.
3 It gets audited through our own internal 4 audit program. It's subject to audit by our nuclear 5 oversight committee. It also reports out to our 6 corporate oversight, nuclear oversight committee that 7 reports to our board of di rectors. 8 We also focus heavily on prevention and 9 detection, and if we can spend 80 percent of our time 10 in prevention and detection, we can find issues at the 11 early onset and deal with them quickly so that the 12 actions that we have to take at that point are relatively 13 small and manageable and easy.
14 When we get into correcting space, we're 15 now having to correct a larger issue, so we want to 16 focus heavily, 80 percent of our time, in prevention 17 and detection, and this is the foundation of how we've 18 operated our fleet since 2008 and we'll continue to 19 do so. 20 CHAIRMAN SKILLMAN: Eric, let me ask this 21 question, and I'm imagining Dr. Rempe's opening 22 question. You're a learning organization. You just 23 communicated that your vision for your co mpany is to 24 jump on issues early and prevent them from becoming 25 27 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 worse. Why then did it take from 2010 to 2014 to really 1 get a grip?
2 MEMBER REMPE: And could I even go a bit 3 further? Wasn't it because of an NRC inspection that 4 the next indicator in 2014 was identified? And the 5 reason that I'm again raising this now is because I 6 want to have the concern addressed that you're now 7 looking for other places where something could occur.
8 It was known that ASR expansion could cause 9 buildings, to place different loads on buildings and 10 have the walls deform, and that was what caused, my 11 understanding is, the seal to quit functioning as it 12 should. Is my question clear what I'm trying to say?
13 MR. McCARTNEY: I think your question is 14 clear and I think that through the course of the 15 technical discussion today, we'll probably answer a 16 number of those questions.
17 But one of the things that is a bit unique 18 about the application of ASR at Seabrook is the small 19 growth model. Much of the science involved with ASR 20 was recognizing an early rapid growth period. The 21 testing that we did early on during construction looked 22 for fast growth ASR.
23 I think the team will speak to that in a 24 lot more detail and a lot more technically than I'm 25 28 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 able to, but that, I believe, is the foundation that 1 will speak a bit to that time lag that you asked your 2 question about, Dr. Rempe.
3 MEMBER REMPE: Thank you.
4 CHAIRMAN SKILLMAN: Eric, thank you.
5 Please proceed.
6 MR. McCARTNEY: Okay, thank you, and I'd 7 like now to turn it over to our technical team and Ms.
8 Hulbert will come up and I'll leave back to the back 9 of the room.
10 MR. BROWNE: Thank you, Eric, and thank 11 you, Mr. Chairman. I'm Ken Browne, licensing manager 12 for Seabrook Station. I've b een at Seabrook for 28 13 years. 14 I've held positions in operations, 15 including a senior reactor operator's license, varying 16 positions in the control room up through ops director, 17 several years in accredited training, and then the last 18 three years, I've been involved as a regulatory 19 compliance and project management sponsor for the 20 alkali-silica reaction project at Seabrook.
21 We've prepared a very comprehensive 22 presentation for you today. I believe it will address 23 the Committee's requests and concerns that you 24 articulated at the beginning of the meeting.
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-3701 (202) 234-4433 Just a bit of background, since Seabrook's 1 last presentation at the ACRS Subcommittee, NextEra 2 and its specialty contractors have been engaged in 3 industry leading research in establishing a safe, 4 reliable metho d for understanding the effects of ASR 5 and also how it affects concrete and safety
-related 6 structures.
7 CHAIRMAN SKILLMAN: Let the record show 8 that that last interaction with the ACRS was in 2012.
9 MR. BROWNE: That is correct.
10 CHAIRMAN SKILLMAN: It's been six years.
11 MR. BROWNE: That's correct.
12 CHAIRMAN SKILLMAN: And I'm not assigning 13 any pejorative connotation to that. I'm just saying 14 it's been a while since we've had you here to explain 15 what you're doing.
16 MR. BROWNE: It has been a while, yes, sir.
17 CHAIRMAN SKILLMAN: Thank you, okay.
18 MR. BROWNE: And at the time, we had spoken 19 about our large
-scale test program which we had just 20 been initiating at the University of Texas, which was 21 to perform disruptive testing on large
-scale beams d one 22 with specimens that were representative of Seabrook's 23 structures.
24 Instead of tests on small sample cores, 25 30 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the large-scale testing would provide data about the 1 structural capacity of ASR
-affected structures at 2 Seabrook, which as we all know, has signifi cant 3 reinforcement.
4 We had since completed that large
-scale 5 testing and it has demonstrated that there is no loss 6 of structural capacity for levels of ASR expansion 7 beyond that presently observed at Seabrook. The 8 results of the lar ge-scale programs have been 9 incorporated into our structures monitoring program 10 and into evaluations of ASR
-affected structures, and 11 as part of today's presentation, we will discuss in 12 detail how we determined that ASR conditions at Seabrook 13 are within the bounds of the Texas program.
14 Another change since our presentation is 15 that we've expanded the ASR project to include the 16 monitoring of building displacement and deformation 17 caused for ASR
-related expansion.
18 As noted, over the past few years, we began 19 to recognize that certain susceptible areas in the plant 20 had shown relative movement due to ASR expansion. This 21 was evident to us in components like seismic gaps, flex 22 conduits, and we do have some photographs of that as 23 part of our presentation, and in som e cases, instrument 24 tubing which had become misaligned.
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-3701 (202) 234-4433 At that point, we enlisted the services 1 of Simpson, Gumpertz, and Heger out of Boston, who 2 performed inspection and analysis of these effected 3 buildings to ensure that the ASR
-affected displacement 4 would not alter Seabrook's compliance with its design 5 code margins.
6 As data is integrated and continues to be 7 integrated from monitoring these buildings, we will 8 continue to update these evaluations throughout the 9 period of extended operation.
10 MEMBER REMPE: So this is, I guess, a good 11 place. You clearly have identified some buildings.
12 Are you looking for other locations that you have not 13 yet identified? I think there's feedback.
14 Okay, that's what I was concerned ab out 15 because, you know, what's happened in the past has 16 happened, but I want to make sure you're looking at 17 other locations that have not been identified. Thank 18 you. 19 MR. BROWNE: Yes, Doctor, we do have the 20 extensive walk down program that's been in place for 21 several years, and we have that as built into our 22 presentation, our extended condition, the structural 23 analysis, and where we stand currently for evaluation 24 of those structures.
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-3701 (202) 234-4433 MEMBER REMPE: Thank you.
1 CHAIRMAN SKILLMAN: If I can ask, what is 2 the connection between that walk down program and the 3 entry of data into your corrective action program?
4 MR. BROWNE: Maybe Jackie Hulbert may be 5 better to answer that one, but right now, the walk down 6 data is entered into the CAP as part of the program 7 and we'll demonstrate. We have a couple of slides later 8 on that talks about our structures monitoring program 9 and just some of the tooling we use to make sure that 10 we've captured that by building and we're able to have 11 it all in one place so we understand what's going on 12 in the building.
13 CHAIRMAN SKILLMAN: Okay, thank you.
14 MR. SCHULTZ: Just a question, there is 15 some impression that the NRC's audits have found the 16 structural deformation in certain locations in the 17 plant. Is that the case or is it just an instance where 18 it's an area of the plant once identified in the NRC 19 audit and what is the circumstance there?
20 I'm talking about 2014, the audits that 21 were performed then. It appeared from the audit report 22 that the NRC found elements of structural deformation 23 before the licensee did.
24 MR. BROWNE: The deformation that I think 25 33 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 you're talking about, Dr. Schultz, is our, and you'll 1 hear about it here, is the containment enclosure 2 building.
3 It was noted by a junior re sident at the 4 time that there was, from memory, there was a fire seal 5 or a seismic gap seal that had pulled away from the 6 structure and it was recognized, you know, credit given 7 to the inspector that brought that to our attention, 8 and that is really what led us down the road to 9 understanding more about how ASR was affecting 10 deformation on the structures, so, yes, it was 11 identified by the NRC at that point.
12 MR. SCHULTZ: And that lesson has affected 13 your program that you have in place today?
14 MR. BROWNE: Abs olutely, and we'll talk 15 more about that in subsequent material. Regarding 16 regulatory transmittal over the last several years, 17 we have used the information from the Texas test 18 programs to also prepare two important licensing 19 actions for Seabrook.
20 We've s ubmitted a license amendment 21 request, as Mr. Burton has noted, since relevant design 22 codes that Seabrook was built with did not consider 23 the loads resulting from alkali
-silica reaction, and 24 we'll talk about that extensively in our presentation, 25 34 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and that am endment covers the methodology for 1 evaluating ASR
-affected seismic CAT 1 structures at 2 Seabrook. 3 This methodology uses the results of the 4 large-scale testing program to determine the structural 5 capacity of concrete structures at Seabrook and defines 6 the analytical methodology used to evaluate these 7 structures.
8 The methodology also includes monitoring 9 to ensure that structures remain within limits of the 10 large-scale testing program and within its design 11 margins as established in the s tructures analysis.
12 We have also enhanced our license renewal 13 aging management program for alkali
-silica reaction, 14 which was the program we first presented back in 2012, 15 to account for the results of the large
-scale testing 16 program. 17 I'm going to move to in troduce our team 18 on the next several slides. We've brought a number 19 of NextEra individuals and also our specialty 20 engineering firms that have assisted us over the years 21 with getting to this point.
22 I won't go into specific details of 23 introductions on our contractors, but I will just go 24 through the highlight, the slides, and the team leads 25 35 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 just to move us into the presentation, Mr. Chairman.
1 The NextEra representatives are, as Eric 2 has mentioned, here, and all of these will be speaking 3 at some point during today's presentation.
4 We also have, excuse me, we also have MPR 5 Associates who is a well
-known industry expert. They 6 are a multidisciplinary specialty firm with roots in 7 the nuclear power industry, and John Simons is here 8 leading that team from MPR.
9 We have Simpson, Gumpertz and Heger, which 10 we're lucky to have, out of the Boston office, which 11 is in close proximity to Seabrook, and they're a 12 national engineering firm that designs, investigates, 13 and rehabilitates structures, an d Dr. Said Bolourchi 14 is here leading that team and he'll be making a large 15 part of our presentation today.
16 And lastly, we have some distinguished 17 technical consultants, notably Dr. Bayrak, who ran our 18 program at the University of Texas at Austin, and Dr.
19 B ruce Ellingwood of Colorado State University.
20 I'm going to turn the presentation over 21 to Mike Collins, our engineering director, to walk us 22 through the background and introduction to ASR from 23 an engineering perspective.
24 MR. COLLINS: Good morning, my name is 25 36 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Michael Collins and I'm the Director of Engineering 1 at Seabrook Station. I have 37 years' experience in 2 the nuclear industry, 17 years with Stone and Webster 3 Engineering, with new build construction, and also 4 continuing services at operating facilities , and 20 5 years at Seabrook Station, the last four
-and-a-half 6 years in which I functioned as the Director of 7 Engineering.
8 So my part of the presentation here will 9 be the background of our station and also lay out how 10 we're going to proceed today with our discussions and 11 presentations.
12 Seabrook Station is a single unit 13 Westinghouse four
-loop pressurized water reactor with 14 a General Electric turbine
- 15 OPERATOR: The conference is now in silent 16 mode. 17 MR. COLLINS: We're located in the t own 18 of Seabrook, New Hampshire, two miles west of the 19 Atlantic Ocean, approximately two miles north of the 20 Massachusetts state line, and 15 miles south of the 21 Maine state line.
22 Our reactor is housed in a steel
-lined 23 reinforced concrete containment structur e which is 24 enclosed by a reinforced concrete containment enclosure 25 37 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 structure. This containment enclosure building, 1 otherwise known at the station as the CEB, is a structure 2 that actually encapsulates our containment building.
3 4 So if you're onsite and you look at the 5 rounded structures at many facilities, it is in fact 6 a containment building. That's not the case at 7 Seabrook Station. That's our containment enclosure 8 building. 9 MEMBER RICCARDELLA: Excuse me, is that 10 building also the missile shield for the containment?
11 MR. COLLINS: The containment still has 12 its analysis for missile shields, and we do have 13 protection of missile shields that we'll discuss in 14 one aspect of the presentation, to protect penetrations 15 going through that ar ea from the containment enclosure 16 structure to containment itself.
17 MEMBER RICCARDELLA: But does the CEB also 18 function as a missile shield?
19 MR. COLLINS: That is correct.
20 MEMBER RICCARDELLA: Okay, thank you.
21 MR. COLLINS: We're at 3648 megawatt 22 thermal power and 1250 net megawatts electric. The 23 Atlantic Ocean is our ultimate heat sink. The seismic 24 category one mechanical draft cooling tower provides 25 38 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 additional safe shutdown capability for the ultimate 1 heat sink. Next slide, please.
2 This is an aerial vie w of our station, both 3 the unit controlled area and our protected area.
4 Again, we're two miles inland west of the open Atlantic 5 Ocean. Next slide, please.
6 And this is the
- as originally designed, 7 this station was to be a two unit site. It's broken 8 down, which we call the 50
-yard line, down the middle 9 of the station. This side of the station is Unit 2, 10 which construction on that Unit 2 was terminated in 11 1984. The construction permit expired in 1988. That 12 is outside our protecte d area as it stands.
13 Some of our major buildings that can be 14 seen is our containment structure, our fuel storage 15 building, our service water pump house, our primary 16 auxiliary building, the seismic cat one safety
-related 17 cooling, mechanical draft cooling tower that was just 18 mentioned, our residual heat sink removal vaults, and 19 our controlled building which houses our emergency 20 diesel generators.
21 So just quickly going through our licensing 22 timeline, construction permit July 1986, zero power 23 operating license October 1986, low power operating 24 license in 1989, our full power operating license March 25 39 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 1990, and as was stated earlier, our commercial 1 operation August 1990, operating license transfer to 2 Florida Power and Light, now NextEra energy November 3 2002. 4 Our stretch power operate the 3587 5 megawatts was in February 2005. We went through a zero 6 power recapture which the NRC then issued amendment 7 105 to the Seabrook facility operating license 8 extending the expiration date from October 17, 2026 9 to March 15, 203
- 0. 10 CHAIRMAN SKILLMAN: Michael, what was the 11 action undertaken for the stretch power upgrade? What 12 did you do there?
13 MR. COLLINS: It certainly wasn't the 14 magnitude of the large station's extended power to 15 operate. We placed some rotating elements in our 16 condensate pumps. We didn't replace any feedwater 17 heaters.
18 We didn't replace any feedwater pumps.
19 Rather minimal, we fit our MSRs from a two pass to a 20 four pass. It wasn't as large, again, as our facilities 21 down south such as St. Lucie and Turkey Point 22 encountered.
23 CHAIRMAN SKILLMAN: Did you change your 24 fuel or did you change your operating cycle length?
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-3701 (202) 234-4433 MR. COLLINS: Yes, fuel design was changed 1 through an 18
-month design of our fuel cycle.
2 CHAIRMAN SKILLMAN: Okay, thank you
. 3 MEMBER RICCARDELLA: What was the prior 4 thermal power limit?
5 MR. BROWNE: The original licensed thermal 6 power was 3411 megawatts.
7 MR. COLLINS: Again, we had a slight more 8 increase in power with a two percent uncertainty up 9 rate with instrument uncertainties we took advantage 10 of. Our license reapplication was submitted in May 11 2010 and our present operating license expires March 12 15, 2030. 13 The present status of the ASR effort at 14 Seabrook Station, to date, we've completed a 15 comprehensive effort to conduct large
-scale testing 16 to understand the structural implications of ASR. From 17 that, we've developed methodology for evaluation of 18 ASR-affected structures.
19 We're evaluating, presently evaluating all 20 our seismic category one structur es. There's 26 of 21 those structures. And we're developing a monitoring 22 strategy of ASR
-affected concrete and associated system 23 structures and components.
24 We demonstrated compliance evaluated our 25 41 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 seismic category structures and comply with the 1 proposed licensing basis as amended in the LAR, and 2 we have identified areas where modifications to 3 structures are underway and required.
4 And as stated earlier, we're actively 5 engaged with NEI, EPRI, and other working groups to 6 make sure we're actively tracking deve lopments and any 7 other ASR research not conducted by ourselves.
8 NextEra Energy Seabrook has implemented 9 an effective program for evaluating and managing the 10 impacts of ASR on effected concrete structures and 11 associated system struct ures and components.
12 CHAIRMAN SKILLMAN: Michael, you 13 mentioned the numeric 26 structures. Is that 26 that 14 are seismic category one or is 26 the number of the 15 ASR-affected structures?
16 MR. COLLINS: 26 that are seismically 17 category one, and each one of tho se are being evaluated 18 via analysis as impacted by ASR as individual 19 structures.
20 CHAIRMAN SKILLMAN: Is that what the 21 station calls the ASR scope?
22 MR. COLLINS: That would be fair to say.
23 We are looking at some other structures that aren't 24 considered category one structures, but are part of 25 42 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 our license renewal activity, and those will be included 1 in the ASR aging management program.
2 CHAIRMAN SKILLMAN: Yes, sir, thank you.
3 MEMBER RICCARDELLA: So I spent some time 4 reviewing the detailed evaluation of the C EB, which 5 was cited as an example of a stage three evaluation.
6 MR. COLLINS: Yes, sir.
7 MEMBER RICCARDELLA: I'm just curious as 8 to the scheduling of similar evaluations on these other 9 26 structures. Are any of the others complete?
Are 10 they going to be complete prior to the period of extended 11 operation?
12 MR. COLLINS: Absolutely is the answer to 13 that question, but we'll certainly go into more depth 14 as far as the amount of structures that are evaluated.
15 Presently 19 of those structur es have their 16 evaluations completed and eight structures are 17 underway. Approximately half of those are in draft 18 format at this point.
19 MEMBER RICCARDELLA: Okay, thank you.
20 MR. SCHULTZ: Will you present more 21 detail, Mike? Will you present more detail on the 22 schedule related to that later today?
23 MR. COLLINS: Yes, sir.
24 MR. SCHULTZ: Thank you.
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-3701 (202) 234-4433 MR. COLLINS: You know, the buildings were 1 prioritized for evaluation with regards to the extent 2 of ASR presently identified in those buildings. The 3 point of discov ery would be early for those buildings.
4 MEMBER KIRCHNER: Michael, could you give 5 us some examples of modifications to structures? How 6 extensive are these modifications and their relative 7 importance?
8 MR. COLLINS: Yes, sir, one of the 9 modifications that has taken place is there's missile 10 shield blocks that are attached to our containment 11 enclosure building as you go out towards the outside 12 of the containment structure that, with regards to 13 missile anal ysis, protect some of our very important 14 penetrations that go from the Seabrook into the 15 containment building.
16 With the relative movement of the 17 containment enclosure building, one of those missile 18 shield blocks actually came in contact with the ID of 19 the containment structure. With that, we remediated 20 that by reestablishing the three
-inch gap between that 21 missile shield block and the outside of our containment.
22 MEMBER KIRCHNER: Thank you.
23 CHAIRMAN SKILLMAN: Michael, when you 24 mentioned the 26 buildings that are categorized, those 25 44 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 are the category one, two, and three in accordance with 1 some of your documentation?
2 MR. COLLINS: You'll see through our 3 presentation today we have several different means of 4 categorizing the extent of ASR and how we specifical ly 5 analyzed those buildings, so those 26 structures are 6 broken up into those three categories which we'll 7 present when we do our detailed discussion of our 8 analysis. 9 CHAIRMAN SKILLMAN: Thank you.
10 MR. COLLINS: Next slide, please.
So the 11 purpose of our presentation today is to describe the 12 comprehensive approach for addressing ASR at Seabrook 13 station, provide an overview of the technical basis 14 for ASR, of the ASR management approach which certainly 15 includes our large
-scale testing, and from that, the 16 methodology for evaluating ASR
-affected structures, 17 and then most importantly for the long term of our 18 station, summarize implementation of the structures 19 monitoring program for aging management of the 20 ASR-affected structures. Next slid e, please.
21 Our presentation outline will include my 22 present presentation of ASR background, our approach 23 to addressing ASR, our technical basis for our ASR 24 management approach via the large
-scale testing 25 45 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 programs, and the structural evaluation methodology 1 of ASR-affected structures, and our implementation of 2 the ASR management approach, our structures monitoring 3 program, and present the status of our relevant 4 licensing actions, our license amendment request, and 5 our licensing renewal application. We will t hen 6 provide conclusions and closing remarks.
7 The background of ASR at Seabrook Station, 8 in 2009 during the Seabrook license renewal process, 9 it was identified that aggressiveness of groundwater 10 chemistry on concrete structures in co ntact with 11 groundwater and soil needed to be determined. Testing 12 was performed, and in August 2010, Seabrook confirmed 13 the presence of ASR degradation of concrete in below 14 grade walls of several category one structures.
15 The identified material properties that 16 were impacts, which again we'll go into detail as we 17 go forward with our presentation, was a loss of 18 compressive strength, loss of tensile strength, and 19 reduction of the modulus of elasticity.
20 What ASR is, ASR occurs in concrete when 21 reactive silica in the aggregate reacts with hydroxyl 22 ions and alkali ions in the pour solution, the cement.
23 Hydroxyl ions detach the silica anions which then 24 combine with the alkali ions. The reaction produces 25 46 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 an alkali-silica gel that expands as it absorbs 1 moisture, exerting tensile stress on the surrounding 2 concrete and results in the cracking that we'll discuss 3 in detail in our presentation today.
4 What we have behind myself here on the shelf 5 here are several samples of slices of core bores we 6 have taken, you know, to give you a feel for the size 7 of the cracking that we're discussing in the concrete 8 pour. 9 We also have an example of the extensometer 10 which is the device that we're using to measure through 11 wall expansion, which we'll call the Z di rection 12 expansion of our concrete walls, and we have an optical 13 device that we use for our crack mapping, and also 14 finally petrography slides for the thin slices of the 15 material they take for the petrographer to look at to 16 determine what level of ASR we ha ve in that core sample.
17 You're free to look at that during the breaks. If 18 you have any questions, please talk to one of the 19 individuals supporting this presentation.
20 So these are pictures looking at 21 ASR-affected structures outside of Seabrook Station.
22 T hese photos will look very familiar to the pattern 23 cracking that has been seen at our station and also 24 through the country's infrastructure. As you will hear 25 47 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 today, ASR is an aging effect and has been known in 1 the concrete industry since the 1930s.
2 CHAIRMAN SKILLMAN: Before you change that 3 image, this is not Seabrook. This is another place.
4 MR. COLLINS: That is correct.
5 CHAIRMAN SKILLMAN: What other places are 6 we looking at, please?
7 MR. COLLINS: These are samples. I don't 8 know if SG&H can help me with that. They're most likely 9 bridge abutments. That's correct, bridge abutments.
10 CHAIRMAN SKILLMAN: Bridge abutments in 11 Walla Walla, Washington?
12 MR. CARLEY: Commonwealth of 13 Massachusetts.
14 CHAIRMAN SKILLMAN: In the Commonwealth 15 o f Massachusetts, bridges that do what?
16 MR. COLLINS: Matt, can you help me with 17 this? 18 CHAIRMAN SKILLMAN: Do they support 19 automobile traffic? Do they support railroad traffic, 20 both, neither?
21 MR. SHERMAN: This is Matthew Sherman with 22 Simpson, Gumpertz, and Heger. These were photographs 23 that we've taken on other projects where we were working 24 for the Massachusetts Department of Transportation.
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-3701 (202) 234-4433 There is retaining walls there that are supportin g 1 backfill on the upper right.
2 There are bridge abutments, I believe, on 3 the lower left and lower right. So we're doing the 4 same types of observations and measurements. So 5 they're carrying traffic. It's well known. ASR is 6 well known in the transporta tion industry.
7 CHAIRMAN SKILLMAN: Okay, those white 8 buttons on the lower left image, those are extensometer 9 penetrations out of that monolith?
10 MR. COLLINS: Matt, I'll take it from here.
11 No, sir, they're not. Those are pins that are used 12 to measure implant expansion in the X and Y direction.
13 Those will be addressed in detail from both the 14 large-scale testing program and also our structures 15 monitoring program.
16 CHAIRMAN SKILLMAN: So you're using these 17 devices in places other than at Seabrook to determine 18 the extent to which this concrete is expanding?
19 MR. COLLINS: Yes, sir.
20 CHAIRMAN SKILLMAN: Okay.
21 MEMBER RICCARDELLA: Yeah, I have a 22 related question. So you have two pictures of 23 individuals, it looks like, with calipers measurin g 24 crack width. Are those the, are they applying like 25 49 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the CI, the crack index method?
1 MR. COLLINS: Those are the pin to pin 2 measurements that are used in our component cracking.
3 MEMBER RICCARDELLA: Okay, so that's
- 4 CHAIRMAN SKILLMAN: And the CCI?
5 MEMBER RICCARDELLA: And the CCI, so 6 that's not something that was just invented for 7 Seabrook. That's something that's fairly well used 8 in the concrete industry?
9 MR. COLLINS: That's correct, and you'll 10 see how we use that, although we looked at different 11 methods of what we were going to use for instrumentation 12 going forward, and that was developed during the 13 University of Texas large
-scale testing. There will 14 be a section in our presentation on how we derived what 15 instrumentation we would use to track our ASR growth.
16 MEMBER RICCARDELLA: Thank you.
17 CHAIRMAN SKILLMAN: Were these images 18 taken only in the state of New Hampshire?
19 MR. COLLINS: Massachusetts, sir.
20 CHAIRMAN SKILLMAN: Oh, how about Maine?
21 MR. COLLINS: I don't have any pictures 22 from Maine.
23 CHAIRMAN SKILLMAN: If I went to Maine, 24 would I find stuff like that?
25 50 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. COLLINS: I would say yes.
1 CHAIRMAN SKILLMAN: And also in New 2 Hampshire?
3 MR. COLLINS: We don't want to leave New 4 Hampshire out. Yes, sir, you would find that also. 5 CHAIRMAN SKILLMAN: Thank you, okay.
6 MR. COLLINS: Next slide, please. So the 7 ASR background, causes of ASR, original plant 8 construction, preventive measures were taken during 9 plant construction to prevent the development of ASR.
10 We did aggregate, using aggregate reactivity testing 11 and we u sed low alkali cement.
12 Where we are today with the knowledge of 13 reactive, slow reactive, slow moving reactive 14 aggregate, the ASTMs that were used during original 15 plant construction were not effective in identifying 16 the aggregate that we had was slow reac tive. 17 Today's dates, we use updated ASTMs that 18 are recommended in a modern test nuclear plants can 19 use for aggregate reactivity test data.
20 Current state of knowledge on this, ASTM 21 test methods used during plant construction were not 22 reliable as an effect ive means to identify slow reactive 23 aggregate, and also finally, limiting alkali content 24 of cement alone was not sufficient itself to prevent 25 51 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the ASR phenomenon. Next slide, please.
1 So it was the visual identification of 2 pattern cr acking in the 2009 time frame with the 3 identification of aggressive groundwater, which is 4 about 500 ppm chlorides, that led us to doing the 5 investigation in the walls, which led to the core bores 6 and petrography and the identification of ASR in our 7 walls. 8 MEMBER MARCH
-LEUBA: So, Michael, for my 9 education again, is this an education with a bad 10 concrete mix that you bought 40 years ago, or is this 11 an issue with groundwater, or both?
12 MR. COLLINS: It's an issue with regards 13 to the aggregate we used in the con struction of our 14 station. 15 MEMBER MARCH
-LEUBA: Yeah, but what is the 16 source of the sodium? Is that groundwater or was it 17 in the concrete to start with?
18 MR. COLLINS: It was not in the concrete 19 to start with. We have not had any above that level 20 since 2011. The source of sodium could be as easy of 21 the rock salt we spread around the station in the winter.
22 It's not tied directly to us being on a marsh or being 23 close to the ocean, and then the issue of groundwater, 24 we'll go into that with a little more deta il. 25 52 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 We have buildings above grade subjected 1 to ambient humidity that have the same levels of ASR 2 as we do in the lower elevations that are impacted with 3 true wall groundwater, so we can't tie groundwater, 4 ASR directly to the prese nce of groundwater. It's 5 evident above grade and also below grade.
6 Again, we discussed this. This is again 7 one of the mechanisms we use which we'll discuss in 8 detail to monitor X, Y in plane expansion of the cracking 9 concrete. 10 So implications of ASR at t he station, 11 you'll see in the upper right
-hand corner, that's just 12 industry literature for expansion effects of ASR on 13 unreinforced concrete, so that data applies to the 14 investigation and the analysis that we've done for 15 unrestrained concrete structures wh ich we'll, 16 unrestrained concrete cores that we'll discuss later 17 in our evaluation.
18 As I mentioned earlier, ASR impacts the 19 reduction of material properties and their effect on 20 structural capacity, again, compressive strength, 21 tensile strength, and modulus of elasticity.
22 CHAIRMAN SKILLMAN: Michael, please
- 23 excuse me, go ahead.
24 MEMBER REMPE: In some of the background 25 53 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 information that I have found, I observed that they 1 had a lot of cautions in the industry that just because 2 you don't see cracks, you need to be concerned about 3 structural deformation because it's below grade, and 4 obviously that's proven to have happened at Seabrook.
5 MR. COLLINS: Yes, it has. So thank you 6 for the lead in on effects of ASR expansion on structural 7 demands. That is being handled by our analysis we're 8 doing, and structural deformation as evident in this 9 station, you can see on the lower left.
10 That is reflecting relative movement 11 between structures, and then on the right, you'll see 12 those are electrical fl ex connections that are between 13 structures and reflecting relative movement between 14 the structures.
15 CHAIRMAN SKILLMAN: Michael, please explain 16 what the lower left image is portraying.
17 MR. COLLINS: The lower left image is the 18 concrete structure has pulled a way from a metal, we 19 call it a kick plate, in that area of the building.
20 MEMBER MARCH
-LEUBA: Sorry, I didn't get 21 that. The part moved a couple of inches to the left.
22 Is that what you're saying?
23 MR. COLLINS: That's correct.
24 CHAIRMAN SKILLMAN: Thank you.
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-3701 (202) 234-4433 M R. SCHULTZ: Michael, the graph 1 information, is that showing Seabrook data, testing 2 data? 3 MR. COLLINS: It is not. It's just 4 ourselves just reflecting that what we'll present today 5 with regards to unreinforced concrete is in line with 6 industry practices.
7 MR. SCHULTZ: So we'll see more later?
8 MR. COLLINS: Yes, you will.
9 MR. SCHULTZ: Thank you.
10 MR. COLLINS: So we're going to become very 11 familiar with this slide through the presentations 12 we're going to make today. This flow chart is the 13 layout and explains the integrated approach that 14 NextEra Seabrook has developed in response to the 15 identification of ASR in our concrete structures.
16 All of the ASR related efforts fit and flow 17 together, and all results, conclusions, lessons learned 18 are incorporated into the structures monitoring 19 program. 20 Before we go into each section of our 21 detailed discussions today, we'll discuss each one of 22 these blocks shown on this flow diagram, and the 23 respective block will be presented in the front of that 24 discussion, so as you go through, you can piece our 25 55 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 process together.
1 MEMBER BALLINGER: This may not be the 2 right point to ask this question, but in all of the 3 presentations, I don't see explicit comment on any 4 interaction between t he Seabrook folks and the other 5 ASR related programs that are undergoing funded by DOE.
6 NIST has a big program that's looking at concrete 7 degradation. Are you guys connected or following those 8 programs? 9 MR. COLLINS: We are knowledgeable and are 10 followin g. We haven't been fully engaged in those 11 programs. 12 MEMBER BALLINGER: Because they're very 13 extensive in terms of full scale testing and a lot of 14 it's being done at the University of Texas. Tennessee?
15 I thought Texas as well, but anyway, okay, so you 16 ha ven't been?
17 MR. COLLINS: Well, again, we're 18 knowledgeable of the activities, but we haven't had 19 teams associated with those activities.
20 So with regards to just a quick overview 21 of each one of the aspects of our overall approach, 22 we have the large
-scale te sting conclusions, our input 23 into our structures monitoring program. Large
-scale 24 testing conclusions are input to our structural 25 56 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 evaluations. ASR load factors have been derived for 1 use in our structural analysis.
2 Our evaluation methodology and guidance 3 was developed out of both the ASR load factor 4 development and also our large
-scale testing. Our 5 field data is used to feed into our structural 6 evaluation of our 26 seismic category one buildings, 7 and structural evaluation results then feed into our 8 ongoing monitoring and evaluation effort.
9 MEMBER RICCARDELLA: Tell me a little bit 10 about the ASR load factors. What are we referring to 11 there, please?
12 MR. COLLINS: I can't explain that because 13 it's over my head. You will be
- I am ho nest on that.
14 That will be discussed in
-depth by SG&H in their 15 presentation.
16 MEMBER RICCARDELLA: Thank you. I was 17 just trying to understand whether those are safety 18 factors applied to the ASR or factors that are projected 19 or allowing for projection of a dditional ASR in the 20 future. 21 MR. COLLINS: Those are derived safety 22 factors for the analysis.
23 MEMBER RICCARDELLA: Okay, thank you.
24 MR. COLLINS: I apologize I couldn't 25 57 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 answer that, but I wouldn't do it justice.
1 MEMBER RICCARDELLA: Okay.
2 CHAIRMAN SKILLMAN: Michael, let me ask 3 this question. The image that showed the displacement 4 raises in my mind my own years of being involved. Not 5 all buildings' displacements would be of concern, but 6 there are some places where a change, where a 7 displacement could be a very large concern.
8 For example, up in your spent fuel pool, 9 if you got some walk on your north/south walls, you 10 could take your fuel handling gear out of plumb or out 11 of track and out of trolley.
12 If you have movement in your primary shield 13 in your reactor cavity, you can offset the points of 14 loading for the reactor coolant systems, support for 15 the reactor vessel for your reactor coolant pumps and 16 for their capability to resist seismic loads or to be 17 aligned pr operly. 18 Would you say something, please, about how 19 the plumbers at the site and the operators at the site 20 really viewed differential movement relating to 21 operability and to the integrity of your license?
22 MR. COLLINS: Absolutely, so via our 23 structures monitoring program, we all monitoring all 24 of the structures at this point. That's fully 25 58 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 developed. We actually do our target surveys in the 1 fuel storage building to make sure relative movement 2 isn't impacting any of those structures. There's been 3 no, as you explained, tell
-tale signs in that structure 4 of issues.
5 The containment building, there's been no 6 ASR identified within the containment building. We'll 7 talk a little later. There's been some very sma ll areas 8 on the outside wall of containment that have been 9 addressed with ASR.
10 We've also, to have more eyes in the field, 11 we have trained both the operators and the engineering 12 staff on the aspects of ASR and what to be looking for 13 so that a daily opera tor round, he is looking for those, 14 so again, we will identify the issues early and put 15 them into the structures monitoring program.
16 If they're not conforming and considered 17 degraded, an AR is written and they're put into our 18 corrective action program.
That gives the shift 19 manager a look at it right out of the gate to make an 20 initial operability call on that item. So all hands 21 are on deck for the station looking for the impacts 22 of ASR on our structures.
23 CHAIRMAN SKILLMAN: Will you talk about 24 this later today? 25 59 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. COLLINS: We'll talk about it later 1 today with regards to Jackie Hulbert's presentation 2 of our structures monitoring program.
3 CHAIRMAN SKILLMAN: Okay, thank you, all 4 right. 5 MEMBER REMPE: But just to clarify, did 6 you say, "We are now monitoring all structures on the 7 site for deformation and movement," not just the 8 category one or the ASR
-affected structures, but all 9 structures? Is that what I heard you say?
10 MR. COLLINS: I believe we're focusing on 11 the category one stru ctures at this point.
12 MS. HULBERT: We are, but our structures 13 monitoring program as well encompasses all structures, 14 so we look for that pattern cracking under, like, the 15 maintenance rule portion.
16 MEMBER REMPE: But deformation, just 17 pattern cracking or
- 18 MS. HULBERT: So deformation, we're 19 monitoring seismic category one structures.
20 MEMBER REMPE: Just the category one, 21 okay. Thank you.
22 MEMBER MARCH
-LEUBA: For my own education, 23 this expansion, is it overnight or is it, I mean, is 24 it a meter a year, or you go home on a Friday and Monday 25 60 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 you show up and it's moved two inches?
1 MR. COLLINS: No, sir, the progression of 2 ASR is very slow moving.
3 MEMBER MARCH
-LEUBA: Okay, so if you have 4 a decent - 5 MR. COLLINS: Years.
6 MEMBER MARCH
-LEUBA: - program to look for 7 it, you will see it?
8 MR. COLLINS: Yes, sir.
9 MEMBER MARCH
-LEUBA: Okay.
10 MR. BROWNE: And Mr. Chairman, if I could 11 revisit your question, as a result of our root cause 12 for the containment enclosure building deformation that 13 we discuss, one of the actions coming out of that 14 corrective action was to, we had a multi
-discipline 15 team which also had operators in it that did a, I think 16 the number was plant engineering guideline 98, which 17 is the comprehensive multidisciplinary walk down of 18 the site, to identify things like you're mentioning, 19 like conduit deformation, pipes that may be offset in 20 their support, safety loaded structures.
So 21 that was all captured out of the initial root cause 22 coming out of CEB and then dispositioned, and it' s also 23 a two-year requirement coming out of tech 98 as well, 24 but we'll talk about that as well.
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-3701 (202) 234-4433 CHAIRMAN SKILLMAN: Thank you.
1 MR. SCHULTZ: Mike, you've had almost 10 2 years of experience with this now. When you say slow 3 moving, are we talking weeks, months, years, or does 4 that vary?
5 MR. COLLINS: We're talking decades.
6 MR. SCHULTZ: Thank you.
7 MEMBER DIMITRIJEVIC: But you have 8 identified, according to this, all of the potential 9 impact on plant systems and factors, right? So, an d 10 you know what was potentially impacted on the safety 11 of the plant due to this, right? And did you use that 12 in prioritizing some of the problems?
13 MR. COLLINS: So we have used our walk down 14 data to prioritize the first buildings that went into 15 analysis.
That's correct, and then again, the daily 16 walk downs of the building structures monitoring 17 program, if anything is new or identified as moving, 18 it goes into our corrective action system.
19 MEMBER DIMITRIJEVIC: Okay, but you're 20 having a comprehensive release of all the systems and 21 components that could be impacted?
22 MR. COLLINS: Ms. Hulbert will show the 23 comprehensive database that we maintain for all 24 buildings and building areas and the observations in 25 62 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 those areas.
1 MEMBER DIMITRIJEVIC: And you have 2 comprehensive risk assessment as I am familiar that 3 Seabrook has, and I know you have a daily observation 4 too on the daily activities, so did this in any, did 5 you do any risk analysis on this potential impact on 6 the systems and components?
7 MR. COLLINS: As far, I mean, certainly 8 if we find something that is impacting a system 9 structure or component in a degraded way, that risk 10 analysis happens at what we call T
-zero, right away 11 for its impact on the station.
12 MEMBER DIMITRIJEVIC: Okay, so t here is 13 nothing that you can say is in progress that can 14 potentially damage this pipe, or these cable trays, 15 or whatever connections or anything?
16 MR. COLLINS: So, you know, to be honest, 17 we have observed items that aren't perfectly straight 18 in a pipe slee ve that have pulled away from walls, but 19 those are being evaluated on a case by case basis and 20 included in the overall program. Next slide please.
21 So just in conclusion before I turn it over 22 for the full presentations that are going to be made 23 today, the large
-scale test program, we have determined 24 that there is no adverse impact on ASR on structural 25 63 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 capacity within the test limits identified via the 1 University of Texas Program. Limits have been 2 established for monitoring of plant structures. Our 3 evaluation methodology define process that considers 4 the impact on ASR on both structural capacity and 5 structural demands of the respective structures.
6 Structure evaluations demonstrate the 7 seismic category one structures comply with the 8 licensing basis as amended by the LAR, and then 9 structures monitoring comprehensive program addresses 10 ASR expansion, building deformation, and impact on 11 system structures and components.
12 NextEra Energy has implemented an 13 effective program for evaluating and maintaining the 14 impacts of ASR on effected concrete structures and 15 associated system structures and components. I'll now 16 turn over the program back to Mr. Browne.
17 MR. BROWNE: Thank you, Mike. Mr.
18 Chairman, that concludes our opening remarks and 19 initial presentation for NextEra, and at this point, 20 the next section is a closed section, so that concludes 21 our remarks.
22 CHAIRMAN SKILLMAN: Kenneth, thank you 23 very much. Ladies and gentlemen, we are going to take 24 a 10-minute break. We will return at four minutes to 25 64 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 10:00 on that clock. We are going to stay on schedule 1 and we are in recess for 10 minutes.
2 (Whereupon, the above
-entitled matter went 3 off the record at 9:46 a.m. and resumed at 1:17 p.m.)
4 CHAIRMAN SKILLMAN: Ladies and gentl emen, 5 let's restart our meeting. We are back in session.
6 We are in the open session and we turn the meeting over 7 to SGH. Gentlemen, please proceed.
8 MR. BROWNE: Thank you, Mr. Chairman. I'm 9 going to turn it over to Dr. Said Bolourchi who is going 10 to le ad us through the SGH portion of the presentation.
11 CHAIRMAN SKILLMAN: Yes, sir, thank you.
12 DR. BOLOURCHI: Thank you very much. I'm 13 Said Bolourchi. I'm the senior principle at Simpson 14 Gumpertz & Heger in Boston.
15 I have worked in the nuclear industry sin ce 16 the very early 1980s and I started my work with John 17 Bloom and Associates and work on many of the, started 18 at Diablo Canyon and then continue with many of the 19 other plant.
20 I will be representing the methodology 21 for the ASR affec ted structure. And in this 22 presentation Mr. Glenn Bell and Matt Sherman, both 23 senior principals from Simpson Gumpertz & Heger, will 24 be helping me along with Bruce Ellingwood that will 25 65 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 be introduced.
1 Each person when they come in they will 2 introduce their background for your information. Next 3 slide. The goal is to present the consistent and 4 repeatable methodology that can be applied to all 5 Category 1 structures at Seabrook.
6 And, but the basic principle in structural 7 engineering, I'm sorry that many of you may not be in 8 structural engineering. But the basic premise is the 9 equation I put on the slide.
10 The structural capacity is the strength 11 of the number that it can resist the load should be 12 greater than total load. That is the concept.
13 In the morning sess ion it was discussed 14 that the effect of ASR will not reduce the code 15 capacities and therefore, we can apply the code equation 16 for calculating the capacity. And in doing that we 17 will keep having reliability of the code into the 18 evaluation.
19 There also, they discussed about the change 20 in the stiffness because of the pre
-stressing.
21 Therefore, now on the right hand side in the load that 22 was originally designed for this structure, for all 23 the structures at Seabrook the ASR was not part of a 24 load that was listed in the UFSAR.
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-3701 (202) 234-4433 Therefore, as part of this part we will 1 define the load associated with ASR and the load factor 2 associated with that. And then also we will discuss 3 the field data to identify what is the status of th e 4 ASR for each individual building.
5 And that we will discuss as part of this 6 methodology. And then we will discuss the modeling 7 procedure to make sure that we will capture what was 8 observed in larger scale testing which includes the 9 pre-stressing effect.
10 Next slide. In the morning some of the 11 questions was answered. But why are we calculating 12 the demand in the structure.
13 If you start with the unreinforced concrete 14 and you expose it to ASR the number will expand but 15 it will not produce any measurable load that will affect 16 the structure.
17 But if the structure is restrained, such 18 as this structure, all the structures in Seabrook, then 19 when it wants to expand the resistance to that expansion 20 will produce imposed load on that structure and that 21 load has to be a ccounted. 22 And that resistance can come from a number 23 of places. It can come from reinforcement, doesn't 24 let it grow therefore it is internal balance between 25 67 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the concrete and steel but the steel, it will produce 1 its loads.
2 Other seg ment of a structure if there is 3 one part of the structure is expanded and the other 4 part is not the transition between that will see a lot 5 of load in the ASR portion and in the area which is 6 not in the ASR portion where you see all this load or 7 if it's adjacent structures or a part that they are 8 holding. 9 Therefore, as a whole if you have, if you 10 are resisting this expansion then you will produce load.
11 And this load can be significant therefore it should 12 be considered in total evaluation on the right hand 13 side of the equation that we said it needs to be done.
14 Therefore, ASR affected structure must be 15 evaluated even if you don't see deformation as such.
16 But it needs to be evaluated. Go ahead, next.
17 Under methodology again we wanted to make 18 sure we calculate d all Category 1 structures to make 19 sure that they will meet the UFSAR as amended by LAR.
20 And in the structural evaluation methodology there 21 are two basic segments that we need to discuss.
22 One is the ASR loading and loads factor 23 to make sure that we maintain the code reliability that 24 it was intended. The other is a document that can be 25 68 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 applied to all structures uniformly for all of that.
1 And this methodology will provide detailed 2 collection of the data and also evaluation of all 3 seismic Category 1 structures. Go ahead. And then 4 now I want to introduce Glenn Bell for discussing the 5 ASR load factors.
6 MR. BELL: Good afternoon, everyone. My 7 name is Glenn Bell. I am senior principal and chairman 8 of Simpson Gumpertz & Heger. I have 43 years' 9 experience in the design, evaluation and rehabilitation 10 of structures of all types.
11 I'm going to address the preparation of 12 the load factors for ASR loading, which as the graphic 13 on the screen shows is input into the structural 14 evaluation methodology. To my right is Professor, Dr.
15 Bruce Ellingwood.
16 Dr. Ellingwood was our independent 17 reviewer for this portion of the work. He is an eminent 18 authority on the theory of structural safety and 19 reliability and has done groundbreaking work in that 20 area no t only in the nuclear industry but in structural 21 engineering in general.
22 And he'll have some comments at the end 23 of my presentation. But he reviewed and validated this 24 part of our work.
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-3701 (202) 234-4433 As Dr. Bolourchi mentioned, the overall 1 objec tive of our methodology is to supplement the design 2 loads used in the original plant design with new ASR 3 loads. And the objective is to do that in a way that 4 maintains that level of structural performance implicit 5 in the original design criteria codes and standards.
6 So we are maintaining all of the loads and 7 load combinations of the original Seabrook design but 8 introducing new ASR loads into those load combinations.
9 Next slide, please.
10 The containment building at Seabrook was 11 designed to the ASME Boil and Pressure Vessel Code, 12 Section 3, Division 2, 1975. All of the other seismic 13 Category 1 structures at the plant were designed to 14 ACI standard 318
-71 version.
15 The ASME and ACI documents are based on 16 different design philosophies. ASME is based on 17 so-called allowable stress design which I will describe 18 while the ACI standard is based on so
-called strength 19 design. 20 Why were different codes and criteria used 21 for different structures? The answer is that ACI 22 318-71 is principally concerned with strength, assuring 23 that the structure's strength is adequate which is 24 appropriate for all of the Category 1 structures at 25 70 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Seabrook but the containment building.
1 The containment building on the other hand 2 serves the dual purpose not only of structur al 3 containment but also containing the radiological 4 consequences of a loss on cooling accident. So the 5 ASME code requires loading capacity criteria that 6 assure these dual purposes through provisions not 7 contained in the ACI standard.
8 In particular, the AS ME code limits 9 stresses in concrete and steel reinforcing to ensure 10 the containment buildings function as a pressure 11 vessel. I go into this detail because the approaches 12 for the design standards and approaches to load factors 13 are different because of thes e dual purposes.
14 So I'm going to take these one at a time.
15 Next slide, please. So let's start with the ASME code, 16 again applied to the containment building. For the 17 containment building the program
-- 18 CHAIRMAN SKILLMAN: Glenn, let me jump in 19 here just for a second.
20 MR. BELL: Yes, sure.
21 CHAIRMAN SKILLMAN: And let me address my 22 question to Kenneth please. So I'm going to go back 23 to being a landowner within three or four miles of this 24 site. 25 71 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 And I am witnessing NextEra building a 1 varsity team of extraordinarily qualified 2 professionals to defend ASR. The question is, why did 3 NextEra not specifically choose this team but why did 4 NextEra go to a strong outside consulting firm, if you 5 will, as opposed to using a group that might be lo cated 6 in Portsmouth, New Hampshire or Manchester, New 7 Hampshire or someone real, real close to the farms and 8 to the land near the plant?
9 MR. BROWNE: Yes, I'll try to answer your 10 question. Obviously it's a complex issue. We were 11 first in the industry in needing to deal with this.
12 SGH is, I would say they are somewhat close 13 because they are out of Boston and I mentioned that 14 earlier that we are fortunate that we have the access 15 to this expertise, you know, literally an hour away.
16 We've had virtually a constant presence 17 from them on site since we started addressing the issue.
18 I'm not sure if that answers your question. But I 19 do respect that it's certainly bringing that type of 20 technology home to New Hampshire and having that locally 21 is certainly an advantage.
22 But in this case the, just the level of 23 expertise we needed in order to understand a very 24 complex problem, first in the industry really drove 25 72 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 us to reach out for this kind of expertise.
1 CHAIRMAN SKILLMAN: Fair enough. I just 2 wanted to explore for those who might say why did you 3 find it necessary to go and get a varsity team from 4 over there versus next door.
5 I think you're saying they're really not 6 that far away. They're just down in Boston and they 7 bring an expertise that is e ssential for this unique 8 phenomenon that this facility is experiencing.
9 MR. BROWNE: That's well characterized.
10 I agree. 11 CHAIRMAN SKILLMAN: Thank you, please 12 proceed. 13 MR. SCHULTZ: Ken, you mentioned that 14 they've been on site since the problem began. Ca n you 15 characterize that more deeply?
16 MR. BROWNE: Yes, Matt Sherman will talk 17 here shortly after Glenn Bell and Liying who is one 18 of our inspectors who is in the audience with us 19 virtually is on site most days and she's been perform ing 20 virtually all of our surface inspections for the plant.
21 She does all of our CCI measurements. And 22 so that takes several days per week of, you know, of 23 her time. So they have really helped us develop the 24 program to where it is right now.
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-3701 (202) 234-4433 DR. BOLOURCHI: We already have seven 1 batch inspector in the field and almost there is no 2 week that we don't have people there since 2010.
3 CHAIRMAN SKILLMAN: Glenn, I interrupted 4 you and I apologize. Let's proceed.
5 MR. BELL: No apology necessary, sir. So 6 we're starting with the containment building under the 7 ASME code. For the containment building Matt Sherman 8 is going to describe our field program in some detail 9 following me.
10 Our work there included crack index 11 measurements at four grids but very extensive vis ual 12 survey employing rope access. That field survey showed 13 that in the containment building there was only limited 14 localized ASR locations on the exterior surface of the 15 containment building.
16 And I'll show you a graphic in a few sl ides 17 from now of the location and the extent of that. So 18 we started with a very conservative initial screening 19 approach in our view of the CB, the containment 20 building. 21 The intent was to do this initial 22 conservative screening and if the analysis did not 23 demonstrate the structure's adequacy according to the 24 criteria that we would conduct further field 25 74 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 measurements, reduce the uncertainty and rerun the 1 analysis. 2 Fortunately, the structure passed the 3 initial conservative screening. Next slide, please.
4 As I mentioned earlier, the ASME code is based on 5 allowable stress design.
6 So it's primary objective is to limit 7 stresses in the concrete and steel reinforcement. And 8 the ASME code requires code checking under so
-called 9 service and load conditions and factored load 10 conditions.
11 Service load conditions are those that 12 apply to scenarios of normal operation of the plant 13 which are expected to occur frequently over the life 14 of the structure. Concrete stresses under these 15 scenarios are kept well below the concrete's ultimate 16 compressive strength and well below the yield strength 17 of the reinforcement.
18 Factored load conditions, however, apply 19 to more severe scenarios that include extreme 20 conditions that could include failure of the reactor 21 cooling system and/or environmental conditions that 22 are considered to be upper bound for the site.
23 In this case the permitted stresses are 24 higher than they are for service load conditions. But 25 75 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 they are still below the concrete compressive strength 1 and below the steel yield strength.
2 There is one exception to the statement 3 that I just made is that some local steel yielding is 4 permitted under factor load conditions when temperature 5 gradients are considered in the analysis. Next slide, 6 please. 7 So the question was asked earlier exactly 8 what load factors are. And this slide describes that.
9 Load factors along with partial safety factors are 10 key to assuring the intended structural performance.
11 As Dr. Bolourchi mentioned earlier, our 12 primary objective in structural en gineering is to 13 assure that the structure has adequate capacity to the 14 load effects imposed on it. That is the capacity must 15 equal or exceed the load effects.
16 That capacity we are concerned with in 17 allowable stress design is assure d through limitations 18 on stresses. The effects of the loads represented on 19 the right hand side of the equation are typically from 20 multiple sources that can include dead load, live load, 21 wind, earthquake, temperature, et cetera.
22 These multiple sources are represented by 23 the S subscript I terms on the right hand side of the 24 equation. And in the case of our present exercise we 25 76 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 are also introducing ASR as a new loading condition.
1 The terms alpha I in front of the SI load 2 effects are the load factors. These are the load 3 factors. There are different load factors for various 4 types of loads in combinations of loads that codes 5 prescribe.
6 The purpose of the load factors is to 7 account for the variability of the actual loads from 8 the values used in design and to ass ure that the overall 9 required reliability, r margin of the safety of the 10 structure is achieved.
11 In allowable stress design the capacity 12 side of the equation on the left is determined by an 13 allowable stress f sub a which cannot be exceeded.
14 The allowable stress is held below a certain critical 15 stress, F sub cr, by applying a partial factor of safety 16 K to the critical stress and K is less than one.
17 So in terms of overall factor safety the 18 K factor and the alpha i's produce an overall factor 19 of safety against exceeding the allowable stresses.
20 The loads and load combinations represented by the ASME 21 code are deterministic.
22 That is, they are not probabilistically 23 based. They are not based on a quantifiable target 24 reliability level, but r ather structural assurance, 25 77 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 performance rather is assured under various scenarios 1 of normal and extreme loading that were posited by the 2 code drafters.
3 In the ASME code most of the load factors 4 are 1.0, although some are 1.25 and 1.5 for severe 5 environmental or abnormal conditions. An example of 6 the application of a load factor higher than one is 7 in the operating basis earthquake when it is applied 8 to extreme and abnormal conditions.
9 Because the operational basis earthquake 10 is a relatively frequently occurring event it needs 11 to be scaled up by some factor larger than one to 12 represent an extreme condition. On the other hand, 13 the safe shutdown earthquake which posits a very extreme 14 condition of seismicity, seismic accelerations uses 15 a load factor of one. Ne xt slide, please.
16 MEMBER CORRADINI: So then for ASR, I think 17 Pete had asked that early on or you had asked somebody.
18 So what is alpha, to work your simple equation 19 backwards is alpha set to essentially make the allowable 20 force equ al to the load?
21 MR. BELL: No.
22 MEMBER CORRADINI: Or you're looking for 23 a margin given in alpha?
24 MR. BELL: Yes, you're looking for a 25 78 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 margin. 1 MEMBER CORRADINI: So in ASR's case you're 2 going to use some additional larger than one value with 3 the ASR loading? 4 MR. BELL: There's a linkage between the 5 severity of the loading and the alpha factor that you 6 use. The more extreme the loading the lower the load 7 factor needs to be to give you the margin that you need.
8 And, excuse me, and in most cases, in alm ost 9 all cases in the ASME code the load factors are 1.0 10 along with an approach that targets an extreme value 11 of loading.
12 MEMBER CORRADINI: Okay.
13 MR. BELL: Okay. Which is actually a 14 segue to the next slide. So consistent with thi s, next 15 slide, please. Consistent with this our approach is 16 to develop ASR loads that have a very small likelihood 17 of exceedance and to use an ASR load factor of one.
18 Next slide, please. This describes how 19 we developed the ASR loads. In our structural 20 methodology we applied ASR loading to structures by 21 defining four zones of ASR severity according to this 22 graphic. 23 And this is similar but not, this is similar 24 both in the ASME application and the ACI application.
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-3701 (202) 234-4433 Zone 1 which is the lowest level of ASR ex pansion is 1 from a cracking index of near zero to .5 millimeters 2 per meter.
3 Zone 2 is from .5 to one. Zone 3, one to 4 two and Zone 4 over two. In the case of the containment 5 building, as I mentioned earlier, we have only a limited 6 amount of ASR and that all falls within Zone 1 where 7 it does occur.
8 And so I've only highlighted with a picture 9 the box showing Zone 1 here. So our methodology for 10 an extreme and conservative application of ASR is to 11 apply to the entirety of the entire zone an ASR strain 12 correspo nding to the upper limit of that zone.
13 And in the stage one analyses we increase 14 that upper limit by another factor of 1.25. So the 15 practice of applying 1.25 times the maximum limit to 16 the entire zone is conservative.
17 In this case with Zone 1 ranging from CI 18 to .1 to .5, we apply a value of .6 across the entire 19 zone. 20 CHAIRMAN SKILLMAN: Glenn, that is, at 21 least it seems to me to be a decision that's driven 22 by an assumption of the thoroughness of the inspection 23 of the containment bui lding. You've said there is 24 little or no cracking or very little limited cracking.
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-3701 (202) 234-4433 MR. BELL: Correct.
1 CHAIRMAN SKILLMAN: How should we judge, 2 if you will, the thoroughness of that inspection?
3 That's a big building.
4 MR. BELL: We have done extensive vis ual 5 survey all over the building that included rope access 6 all the way to the top and found only limited ASR across 7 the containment building. And the next graphic, if 8 I may, help to answer that question will illustrate 9 that. 10 CHAIRMAN SKILLMAN: I'll be ha ppy to wait 11 until the next slide.
12 MEMBER RICCARDELLA: First is why are we 13 using the term CI here rather than CCI?
14 MR. BELL: I should explain that CI and 15 CCI we're using interchangeably with respect to the 16 application of the ASR lo ads. 17 MEMBER RICCARDELLA: Okay. And also I 18 did, I haven't seen the containment building analysis.
19 But I have reviewed the CEB analysis.
20 And I thought I saw in that you are 21 averaging the CI readings over regions, that you weren't 22 just picking the maximum individual value.
23 MR. BELL: You are correction application 24 to the CEB. And I'm going to go on, that's the different 25 81 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 approach that I was talking about in the ACI code and 1 I'll explain how we dealt with that there.
2 MEMBER RICCARDELLA: So for the 3 containment you're using the absolute
-- 4 MR. BELL: Maximum in the zone.
5 MEMBER RICCARDELLA:
-- that you found?
6 MR. BELL: Maximum in the zone augmented 7 by 25 percent.
8 MEMBER RICCARDELLA: Okay. There were 9 zones and regions though in the CEB.
10 MR. BELL: We simply worked with zones in 11 the CEB. 12 MEMBER RICCARDELLA: So the containment 13 was all one region you're saying?
14 MR. BELL: If I could go to the next slide 15 that might help clarify both questions, okay. This 16 is a schematic illustration of the extent of ASR from 17 the extensive visual surveys in the containment 18 building. 19 You see a band of Zone 1 ASR that runs around 20 the base of the cylinder just above the foundation level 21 for a height of about six feet. There is also a band 22 below the equipment hatch shown schematically there.
23 And one other patch that is not shown 24 because it occurs on the back side is a three foot by 25 82 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 eight foot section of, I'm going to call it suspected 1 ASR because we were conservative in our interpretation 2 of the crack ing in that particular area.
3 And that occurs at an elevation of 68 feet 4 which is higher than the level in the equipment hatch 5 that you see here roughly on the far side. So you can 6 see the vast majority of the CEB has no ASR and even 7 where it occurs it's o nly within Zone 1.
8 CHAIRMAN SKILLMAN: How is that captured 9 in your documentation so that a generation to come can 10 review this documentation and have a strong starting 11 point? 12 MR. BELL: We have an extensive log of all 13 of the field work and the photographs associated with 14 that tagged to particular locations over the building.
15 All of that is summarized in all of our reports running 16 all the way down to the application of loads in our 17 finite element analysis for the containment building
. 18 So it's very thoroughly documented, the 19 dates, the locations, photographic documentation, et 20 cetera. 21 CHAIRMAN SKILLMAN: Thank you.
22 MR. BELL: Yes.
23 MEMBER REMPE: So I have a question that 24 will show my ignorance in this methodology. But from 25 83 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the material I read they emphasized the point that a 1 lot of times there's below grade cracking that imposes 2 a load. 3 And yet your presentation emphasized that 4 you used this cracking measurement to base your load 5 on. How do you account for these loads that you can't 6 s ee? 7 MR. BELL: In this particular case if there 8 was, and we looked at this case, if there was expansion 9 to the foundation that would actually alleviate the 10 loads on the cylinder. We ran the analysis both ways.
11 MEMBER REMPE: Okay, good.
12 MR. BELL: And we only reported the worst 13 case which was the assumption of no ASR or no cracking, 14 no expansion in the foundation. But that's a more 15 severe condition because the foundation if it doesn't 16 expand tends to restrain the expansion in the cylinder 17 from the ASR.
18 MEMBER REMPE: Okay, thank you.
19 MR. BELL: Sure.
20 MEMBER BROWN: For the uninitiated again, 21 another one of my dumb questions. Why is it so local 22 as opposed to more, sorry about that. Why is it so 23 locally located as opposed to more uniformly 24 distributed?
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-3701 (202) 234-4433 I mean it seems to be these very unique 1 bands over this entire thing it's all concrete.
2 MR. BELL: As others have said today and 3 I think will continue to say over the course of the 4 day the presence of ASR has some drivers. But there's 5 a lot of randomness to the process.
6 But one of the many drivers is humidity, 7 high humidity. There was a point in time when there 8 was a wet zone on top of the foundation near the base 9 of the cylinder.
10 That's been dried out now but our 11 presumption is that the humidity associated with that 12 drove that band of ASR down at the foundation level.
13 We also know at one point in time there was some leakage 14 in the equipment hatch tunnel between the CEB and the 15 equipment ha tch that probably drove that band of ASR 16 down that you see just below the equipment hatch.
17 MEMBER BROWN: Okay, thank you very much.
18 MR. BELL: Sure.
19 MEMBER RICCARDELLA: Where is grade on 20 this? 21 MR. BELL: I'm sorry.
22 MEMBER RICCARDELLA: Where is grade, wh at 23 level is grade, right at the foundation?
24 MR. BELL: Grade is, help me, Said. It's 25 85 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 near the equipment hatch.
1 DR. BOLOURCHI: Equipment hatch.
2 MR. BELL: Any other questions before we 3 -- 4 MEMBER CORRADINI: Yes, just so we're all 5 on the same page. This i s the containment
-- 6 MR. BELL: Correct.
7 MEMBER CORRADINI:
-- which is inside the 8 CEB. 9 MR. BELL: Right.
10 MEMBER CORRADINI: And the difference in 11 distance between the two that have allowed the visual 12 inspection is about two or three feet?
13 DR. BOLOURCHI: Four and a half feet.
14 MR. BELL: Four and a half feet.
15 MEMBER CORRADINI: Okay.
16 MEMBER RICCARDELLA: What was the three 17 inch clearance that I read?
18 MR. BELL: I think that was reference to 19 a seismic expansion joint earlier. 20 MEMBER RICCARDELLA: Okay.
21 PARTICIPANT:
That was actually the missile 22 shield. 23 MEMBER RICCARDELLA: There's three feet 24 between. 25 86 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. BELL: There's three feet, four and 1 a half feet, I think, annulus between the CB and the 2 CEB. 3 MEMBER RICCARDELLA:
Thank you.
4 MR. BELL: So next slide, please, 5 summarizes the approach to load factors in the 6 containment building. And next slide, please, Ken, 7 thank you.
8 We selected a conservative approach to 9 loads and load combinations by taking the highest level 10 of strain in each zone and applying it to the entire 11 zone and augmenting that by another 25 percent margin.
12 Also we know that the large
-scale testing 13 program that was described earlier demonstrated on 14 average the cracking index measuremen ts conservatively 15 predict ASR strain and furthermore the literature shows 16 that ASR strains measured at the surface of the concrete 17 significantly overpredict the strains at the 18 reinforcement depth which is the depth that we're most 19 concerned with when it co mes to detecting stresses and 20 reinforcement and so forth.
21 So for each load combination for the CB 22 by the ASME code we have applied a conservative value 23 of ASR strain in combination with a load factor of one.
24 Next I will go on to the seismic Category 1 str uctures 25 87 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 other than the containment building, ACI 318
-71. 1 This, as I said earlier, uses a different 2 approach to assuring structural performance than the 3 ASME code and that impacts the methodology that we use 4 for determining load factors. Next slide, please
. 5 These structures, as I mentioned, were 6 designed to the ACI standard 318
-71 which takes the 7 ultimate strength design approach where the primary 8 objective is to assure adequate strength.
9 We check that strength through the code 10 equations which were mentione d earlier with respect 11 to the large
-scale testing program.
12 MEMBER CORRADINI: May I just back you up?
13 MR. BELL: Absolutely.
14 MEMBER CORRADINI: Is the CEB this or ASME?
15 MR. BELL: This. Only the CB uses ASME.
16 All of the other Cate gory 1 structures
-- 17 MEMBER CORRADINI: Only the containment 18 uses ASME?
19 MR. BELL: Did I misspeak? Only the 20 containment, excuse me.
21 MEMBER CORRADINI: The CEB uses this?
22 MR. BELL: The CEB uses this, yes.
23 MEMBER CORRADINI: Thank you.
24 MR. BELL: Thank you. So we check 25 88 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 strength with the code equations that were described 1 earlier. The ACI code also includes secondary, 2 so-called serviceability checks that are made under 3 less extreme loading conditions.
4 But we're primarily concerned here with 5 assuring adequate strength. Next slide, please. This 6 graphic is very similar to the one that I showed for 7 the ASME code where we are looking to assure that 8 capacity exceeds the load effects.
9 The general construct of the right hand 10 side of the equation the load effect side is similar 11 to the application of the ASME code. The capacity is 12 determined a bit differently again, because we're 13 looking to assure adequate strength rather than 14 limiting stresses.
15 So the factor R, is the nominal strength 16 capac ity determined by code equations and it is modified 17 by a partial safety factor fee which is less than one.
18 Now contrary to the ASME code where most of the load 19 factors are 1.0, in the ACI code they generally fall 20 between 1.4 and 1.7.
21 In the case of the UF SAR the application 22 of the operating basis earthquake goes up to 1.9 and 23 there are some numbers smaller than 1.4 for different 24 load combinations. But the point here is that most 25 89 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 of them fall in the range of 1.4 to 1.7 significantly 1 higher than the 1.0 in the ASME code.
2 MEMBER CORRADINI: I'm sorry that I keep 3 on asking this stuff. So if I made a plot of this phi 4 R is always larger than F sub a?
5 In other words, there's got to be 6 equivalence in terms of the loading. So the way I think 7 of it is your phi R capacity term is higher than F sub 8 a. 9 MR. BELL: As a general prospect we're 10 looking at a more extreme condition of structural 11 loading, exactly, yes.
12 MEMBER CORRADINI: Okay, all right, thank 13 you. 14 MR. BELL: Yes. Next slide, please
. 15 CHAIRMAN SKILLMAN: Before you change.
16 From where do you chose the phi?
17 MR. BELL: I'm going to come to that. But 18 actually if you could bear with me for one more slide 19 or a couple more slides I think that will answer your 20 question. Next slide, please.
21 So since the 1980s the underlying approach 22 to design of concrete structures to the ACI standards 23 and many others has been based on probabilistic concepts 24 of structural reliability. These standards use a 25 90 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 quantitative approach to variations in capacity and 1 load effects to achieve a numerical targeted level of 2 reliability.
3 Reliability here is defined as the 4 probability of not exceeding an acceptable measure of 5 structural performance. While the 1971 version of ACI 6 318 was not based on probabilistic concepts work was 7 underway in the mid to late 1970s to define a 8 probabilistic approach.
9 And a key project in laying the groundwork 10 for a probability based structure reliability was 11 undertaken at the Natural Bureau of Standards, now NIST 12 of course. And the leader of that program was Dr. Bruce 13 Ellingwood who was then a research engineer at the NBS.
14 In their work Ellingwood and his colleagues 15 were able to quantify the levels of reliability inherent 16 in the then existing design methods including ACI 17 318-71. So they sort of reverse engineered the 18 problem, if you will.
19 And they laid out an approach for what is 20 called load and resistance factor design going forward, 21 probabilistically based, reliability based 22 engineering. The work evaluated and his colleagues 23 were culminated in a report that is thumbnailed on the 24 left hand side here called Development of a Probability 25 91 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Based Load Criterion for American National Standard 1 A58. 2 This report became the seminal document 3 in structural reliability implementation in codes and 4 standards and is a key reference in our approach to 5 developing ASR load factors for the ACI code for this 6 project. 7 Structural reliability in this context is 8 defined by a term beta reliability index. There's a 9 relationship between the probability of failure and 10 beta. The higher the beta the higher the probability 11 that the structure will remain safe.
12 The methodology to incorporate ASR effects 13 into this analysis employs the NBS study's findings 14 regarding the reliability inherent in ACI 318
-71. The 15 NBS studies show the average reliability or beta for 16 various load combinations to be as shown in the slide 17 here. 18 That is for load combinations involving 19 static conditions basically gravity loads and lateral 20 earth pressure, a beta of 3.0. For load combinations 21 involving wind a beta of 2.5. For load combinations 22 involving the operating basis earthquake 1.75.
23 And we used these target reliabilities in 24 our methodology thus maintaining that level of 25 92 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 reliability inherent in ACI 31 8-71. Next slide, 1 please. 2 So we used a similar zoning approach as 3 I described earlier for the ASME code. But we had very 4 extensive statistical data on cracking index 5 measurements for the plant. We had measurements, 216 6 measurements and 108 grids which w e used for a 7 statistical analysis to feed into beta.
8 And we grouped those into the four zones 9 of severity shown here. Zone 1 being less than .5.
10 Zone 2, .5 to 1. Zone 3, one to two and Zone 4, anything 11 higher than two.
12 And for each zone we determined the ASR 13 strains from statistics gathered over the zones for 14 the entire plant. We mapped the four ASR severity zones 15 onto each structure and we applied in our loading an 16 ASR strain corresponding to the mean value of CI 17 measured in each zone with the application of a load 18 factor on top of that.
19 That addresses the question that I came 20 up earlier I think. And we applied that 21 probabilistically based determined load factor. Next 22 slide, please.
23 So the calculation to achieve the required 24 beta is a bit involved. But this shows the basic input 25 93 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and the sources of information. The target reliability 1 level of beta.
2 It is based on the NBS report, as I just 3 mentioned. The probability distribution of structural 4 resistance is based on the NBS repo rt and out of that 5 come statistics about the resistance to answer your 6 question and also the phi factor, to directly answer 7 your question, comes right out of the ACI code.
8 But that phi factor needs to, the 9 probability distribution of structural resistance 10 needs to be consistent with the NBS report in order 11 for that phi factor to be appropriately applicable.
12 We gained the probability distribution of all of the 13 loads other than ASR based on the methodology of the 14 NBS report.
15 The probability distribution of the ASR 16 load effects we gained from the statistics measured 17 at the plant. And we also need to know the ratio of 18 ASR load effects to the total load effects, a factor 19 that we call k ASR and we found representative values 20 for each ASR zone in our calculation.
21 So these input variables go into a 22 calculation that finds the ASR load factor that results 23 in the target reliability level. Next slide, please.
24 And these are the results of many complex 25 94 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 calculations to determine load factors. Bu t for static 1 load factors for Zone 1, the ASR load factor is 2.0.
2 For Zones 2 to 4 it's 1.6. For wind, 1.7 3 for Zone 1. For Zones 2 to 4, 1.36. For the operating 4 basis earthquake, 1.3 for Zone 1. 1.04 for Zones 2 5 through 4.
6 A couple of comments on this. Number one, 7 these are simply the load factors that apply to the 8 ASR loads. All of the other loads in the combination 9 use the standard code load factors.
10 And you'll note here that the load factors 11 for Zones 2 through 4 are lower than those for Zone 12 1. The reason for that is that the coefficient of 13 variation of the CI statistics in Zone 1 is larger than 14 Zones 2 to 4.
15 And that has to do with the size of the 16 denominator, coefficient of variation being standard 17 deviation divided by the mean. So that's smaller 18 there. 19 There's two other footnotes. Per ACI 20 318-71 when you have load factors, load combinations 21 that involve differential settlement, create shrinkage 22 or temperature change these load factors may be reduced 23 by 25 percent, but t hey may not be less than one.
24 And finally, for an unusual, very unusual 25 95 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 load combinations involving very extreme values of say 1 shut down earthquake and tornado these are not 2 determined deterministically. They are, they are not 3 determined probabilistically
. 4 They are determined deterministically with 5 a load factor of 1.0. I have a concluding slide that 6 perhaps I should pause here for questions before we 7 go to that.
8 MEMBER RICCARDELLA: You need to help me 9 with this table. Are you sa ying you used different 10 load factors on the ASR load when you combined them 11 with these other loads? Is that why there is a whole 12 table here?
13 MR. BELL: We used these load factors in 14 any of the equations that involve loads with ASR 15 loading. So these are the load factors applied to ASR.
16 A typical load combination will include 17 many factors, dead load, live load, possibly wind or 18 earthquake, et cetera. And now they always include 19 ASR load as well.
20 Each of those loads, individual loads has 21 its own load factor. These are the load factors that 22 we applied to the ASR loads in every combination.
23 MEMBER RICCARDELLA: In that specific 24 equation, in those specific loads?
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-3701 (202) 234-4433 MR. BELL: Yes, that's correct.
1 MEMBER RICCARDELLA: But what about, I 2 mean, but don't you have co mbinations that would include 3 static plus wind?
4 MR. BELL: We do. And we included all of 5 those in the calculations that lead to the ultimate 6 reliability level data using the code prescribed load 7 factors for those loads that are cod e prescribed.
8 So we're adding here ASR loading to all 9 of those load combinations. A load that I have 10 described along with specific load factors just for 11 the ASR load. We don't change anything else.
12 MR. SCHULTZ: Glenn, could you walk 13 through one more time why the load factors for Zones 14 2 through 4 are lower than for Zone 1? These are, Zones 15 2 through 4, are those where the cracking index is larger 16 than in Zone 1.
17 MR. BELL: Right. So coefficient of 18 variation is standard deviation divided by the mean.
19 If you go to the next slide the mean in Zone 1 is very 20 small. 21 It ranges between zero and .1. The means 22 of all of the other zones are significantly larger.
23 That's the main driver.
24 Another possible contributor is that the 25 97 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 precision in the optical measuremen ts in the very fine 1 cracks is probably not as high as it is, the wider the 2 crack the more precision that we have in the optical 3 measurements. So those two factors account for that.
4 MR. SCHULTZ: Okay. It's the level of 5 variation divided by
-- 6 MR. BELL: Yes, it's all in the variation, 7 yes. 8 MR. SCHULTZ: I can see that. Thank you.
9 MEMBER RICCARDELLA: The level of 10 variation in the measurements that you've made in the 11 field in a specific zone. Is that what you're, that' s 12 what you're referring to, right?
13 MR. BELL: That and the fact that in 14 computing COV we're using a very small denominator for 15 Zone 1. But I have one more slide if
-- 16 MEMBER RICCARDELLA: I am still struggling 17 -- 18 MR. BELL: Go ahead.
19 MEMBER RICCARDELLA:
-- a little with 20 this. I mean, should the second row really be static 21 plus wind and the third row should be static plus wind 22 and also be
-- 23 MR. BELL: These are load combinations 24 that are principally static. They don't include wind.
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-3701 (202) 234-4433 They can include dea d load and by static we mean dead 1 load, live load, lateral earth pressure. The second 2 row are load combinations that involve wind, et cetera.
3 MEMBER RICCARDELLA: I understand now.
4 Okay, thank you.
5 MR. BELL: So our last slide, pl ease. 6 Oops, no, that's correct, sorry. In conclusion, we 7 developed ASR load factors for both the ASME and the 8 ACI 318 approaches.
9 We used methods that are consistent with 10 the underlying philosophy of the original design 11 criteria. We used methods that ar e consistent with 12 the level of safety and reliability inherent in those 13 codes and standards.
14 And we took a comprehensive and 15 conservative approach at various decision points. And 16 with that I will turn it over to Dr. Ellingwood who 17 has some comments based on his review of the work that 18 I just presented.
19 CHAIRMAN SKILLMAN: Before you do that let 20 me ask a question to NextEra, to Kenneth. Kenneth, 21 if I'm, again I'm a citizen of New Hampshire, I live 22 six miles from this place, will the documentation that 23 defends this be available to me in a publicly releasable 24 form so I can take my calculator and my pencil and do 25 99 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 some calculating?
1 In other words, will there be a version 2 of this that is available to the citizens that are living 3 a couple miles from this facility
? 4 MR. BROWNE: The license amendment request 5 and also the AMP are also, are submitted on the docket 6 for review. So, I guess, simplistically, yes.
7 CHAIRMAN SKILLMAN: Simplistically.
8 Does that mean
-- 9 MR. BROWNE: The proprietary v ersion is 10 obviously redacted for
-- 11 CHAIRMAN SKILLMAN: I understand that.
12 Now is the not proprietary version of sufficient detail 13 that an interested and curious person could pretty much 14 come to the same conclusion that your consultant has 15 come to? 16 MR. BROWNE: The methodology document and 17 also the remaining calculations would need to be married 18 up with the license amendment request in order to come 19 to the same conclusions.
20 CHAIRMAN SKILLMAN: I would like you to 21 think about that just some lessons from what it took 22 to take a plant from not operable to being fully operable 23 given a local next door. We've also seen this, for 24 instance, at Davis
-Besse, which was another 350 plant.
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-3701 (202) 234-4433 And the question was can the public really 1 find a way to come to the same conclus ion without going 2 through extraordinary efforts.
3 MR. BROWNE: No, I understand your comment 4 and several of your questions have been focused around 5 the fact that when you have difficult problems in our 6 industry they're often very dif ficult to, we obviously, 7 we work in a complex industry.
8 And it's a technology that sometimes can 9 be difficult to understand. And then when people don't 10 understand our industry due to the complexity they reach 11 a conclusion that's often adverse to safety.
12 So I understand your comment and we'll work 13 to -- 14 CHAIRMAN SKILLMAN: You know, I'm a 50 year 15 veteran in this, actually a little bit more than that.
16 And what I've learned is the public is mighty smart.
17 MR. BROWNE: Absolutely.
18 CHAIRMAN SKILLMAN: And they are owed good 19 answers because one of the most important features we 20 have in nuclear is that we're open to the community.
21 And if the community can find their way to come to 22 almost the same conclusion without a lot of smoke and 23 mirrors the public gains a l ot of confidence very 24 quickly. 25 101 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. BROWNE: No, I understand your 1 comment, we understand your comment at NextEra.
2 CHAIRMAN SKILLMAN: Okay, thank you.
3 Please proceed.
4 DR. ELLINGWOOD: Thank you, Glenn. I was 5 asked to perform an independent evaluation of the 6 calculations that the SGH team had made in support of 7 the load combinations and the load factors applied to 8 alkali silica reaction structural actions.
9 And in my judgment the conclusions that 10 they arrived at for the containment b uilding and the 11 methods employed are consistent with, you know, the 12 load combinations that appear in Section 3, Division 13 2 of the ASME Boiler and Pressure Code which are in 14 fact deterministically based and historically done that 15 way. 16 For the Category 1 str uctures other than 17 containment, the procedures that they followed were 18 consistent with the procedures that we adopted in 19 developing the probability based load resistance 20 factors for American National Standard A58 which 21 subsequently have been adopted by all the model codes 22 in the United States material specifications and I might 23 add by some overseas code organizations as well.
24 And I think that the load combinations that 25 102 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 have been proposed for the load factors will achieve 1 the target reliabilities that Glenn had produced in 2 support of his recommendations. Thank you.
3 DR. BOLOURCHI: I would like to present 4 Matt Sherman to first come and discuss about the field 5 observations before we get to the actual methodology 6 document because we used this data in that.
7 MR. SHERMAN: Sure. Thank you very much.
8 My name is Matthew Sherman. I'm a senior principal 9 at Simpson Gumpertz & Heger.
10 As Dr. Bolourchi just mentioned we're going 11 to do a little bit of a jump ahead to the field data.
12 And we're going to talk about that before he comes 13 back and talks about how it all feeds into the structural 14 evaluation methodology.
15 We're doing that because it's, the 16 methodology document describes how the field data is 17 actually used in the analysis. And when Dr. Bol ourchi 18 goes through that document he's going to use some 19 examples of how the field data feeds into the structural 20 evaluation methodology.
21 So if we tell you right now a little bit 22 ahead of time how we do the field data when it comes 23 along to talk about how it's used you can concentrate 24 on that part and we can keep kind of the simple 25 103 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 attainment of the data here first.
1 All right, so to reboot, I'm Matt Sherman.
2 I have about 25 years of experience in the civil 3 engineering world mostly i n civil engineering 4 materials, construction, repair and testing.
5 I was the supervisor for the field data 6 acquisition portion of the work. Field data is used 7 extensively in the methodology document. It describes 8 very comprehensively how field data works i
- n. 9 And it's really an integral component of 10 the structural evaluations that were done because it 11 works into an iterative process that lets us interact 12 with information, data and the results of analysis to 13 provide really a robust basis for the calculation.
14 Next slide, please. So if you think about 15 it the methodology document really describes this 16 evaluation process. It uses field data and provides 17 a framework, the methodology document provides a 18 framework for the overall, for the whole process.
19 And it really includes a cycle of analysis, 20 field data and an intelligent interpretation. This 21 is not a linear, one time process. It's a cycle where 22 we use the intelligent interpretation.
23 For example, field testing may include 24 observing crack patterns and measuring expansions.
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-3701 (202) 234-4433 The analysis may be a finite element model that uses 1 some of that data.
2 And then the interpretation is an 3 intelligent comparison and backcheck of those, right.
4 So we have to match the models up with the data and 5 obser ver. 6 So it's an iterative process. So we start 7 with the observations. We might include measurements 8 and possibly some special testing. And it's done by 9 a team of people who are integrated. The field people 10 are integrated with the analysis team.
11 Next slide, please. So for this work we 12 can think of the field data as comprising three main 13 groups. There's, the first one is observations which 14 are kind of non
-quantifiable information.
15 They're non
-quantifiable. There are 16 measurements that are actually dat a that feed into the 17 analysis. And then there are sometimes specialty 18 testing that's used to supplement or to answer special 19 questions that arise during it.
20 All right, all of our work on the field 21 data work was done under full QA, under our full nuclear 22 QA program. All the field teams are two person teams 23 that include different degrees of peer checking to 24 review all the data.
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-3701 (202) 234-4433 And then it's all evaluated through the 1 structural process. Next slide, please. So the field 2 work really starts with observations, right. This is 3 a walk down that guides and shapes the initial analysis 4 and field data gathering.
5 These walk downs are done with full plant 6 support and coordination for safety, access and also 7 as a source of historical knowledge f or what's happened 8 in the plant and provide any background information 9 that's needed.
10 So remember that these observations 11 include information but not necessarily data that we 12 use. Next slide, please. So the observations give 13 us information on the extent of apparent ASR cracking 14 and it provides clues about other types of cracking 15 that may be present for other reasons.
16 Such as on the left here where you can see 17 these diagonal cracks that are highlighted in yellow 18 chalk. Those diagonal cracks are indicative of typical 19 shear forces.
20 You know, so we're using that information 21 and feeding into the overall analysis. The methodology 22 document describes in detail how the observed cracking 23 is incorporated into the analysis using pattern, type, 24 widths, all of that to aid in interpretation.
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-3701 (202) 234-4433 This observation phase is a thinking 1 observation. It's a thinking operation. It's done 2 by people who are integrated into the overall team.
3 MEMBER MARCH
-LEUBA: Quick question. Is 4 this Seabrook?
5 MR. SHERMAN: These are both at Seabrook, 6 yes. 7 MEMBER MARCH
-LEUBA: Okay. So it is the 8 famous tunnel?
9 MR. SHERMAN: This is not the famous 10 tunnel. These are other locations.
11 MEMBER MARCH
-LEUBA: And what, we're 12 talking a maximum of .5 or 5 millimeters per meter 13 expansion. What degree of expansion would say this 14 is? 15 MR. SHERMAN: This one I'm not sure of the 16 number for sure. I have a better example coming up 17 later on. This is low. This would be, the one on the 18 right hand side is down like what Glenn was talking 19 a bout. 20 MEMBER MARCH
-LEUBA: I wonder about those 21 long cracks.
22 MR. SHERMAN: Those aren't ASR cracks.
23 Those are shear cracks, right so that's, the methodology 24 document describes how we do that. For the most part 25 107 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 we assume that they' re ASR cracks and use that 1 conservatively.
2 There are occasions where, Said will get 3 into later on where the methodology document lets you 4 work through and understand that better. So sometimes 5 these observations will also include limited 6 measurements.
7 We'll go to the, there was an earlier 8 question, we go whenever we walk down an individual 9 structure or a room within a structure or a piece of 10 it, we go find the worst area to make measurements on 11 to help us frame what we're going to do there.
12 Again, it's a th inking operation. So 13 we'll do limited measurements to provide initial 14 assessments of severity and location. Really not as 15 a data source per se but to indicate what types of formal 16 measurements are required underneath the methodology 17 document. 18 It shows us what's required as follow up 19 work. We also, during these walk downs we also go to 20 areas and sound the representative surfaces to look 21 for any kind of, with hammers or chains to look for 22 drumming sounding areas or any weak sounding areas all 23 in accordance with the ACI 349.3 document which I was 24 just on the committee that revised.
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-3701 (202) 234-4433 All right, next slide, please. So the 1 observations in walk down really let us incorporate 2 real world data. They let us bring that real world 3 information into our analysis.
4 This is needed because there is some degree 5 of cracking that is fundamental to reinforced concrete 6 behavior. That's in reinforced concrete 101, you know, 7 you have to crack to some degree to activate the 8 reinforcement.
9 That's because the concrete works mostly 10 in compression and it has to crack to let that 11 reinforcement work. And remember there are also other 12 sources of expected cracking such as when we do normal 13 pressure testing of the containment building or in 14 shrinkage causes cracking or anybody who walks around 15 who has a concrete basement knows that you have cracks 16 and look at your sidewalk when you're walking down.
17 So based on during the observations and 18 walk down we outline any cracks with chalk and identify 19 the patterns that may be unrelated to ASR within the 20 concrete. For example, on the left hand side again 21 those are those shear cracks that are highlighted in 22 yellow chalk.
23 We also document other information that 24 can feed into the analysis such as relative building 25 109 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 movement that could be related to expansion. For 1 example, the photo on the right shows the movement of 2 the conduit flex joints.
3 Movement direction and offset degree can 4 be used to calibrate the structural models, as Said 5 will describe in a minute. Now each one of these 6 structures, an earlier question about how, where the 7 data is available every structure that we go out has 8 a site visit report that's issued that has a full 9 breakdown of it and those are on the docket.
10 MR. SCHULTZ: Matthew, before you move on.
11 MR. SHERMAN: Yes, sir.
12 MR. SCHULTZ: The observations, I know 13 this is the first stage, if you will, of the 14 investigation. But you said that the, I just want to 15 check what you said, what I thought you said.
16 And that is this is done by a quali fied 17 team that knows what they're looking for. It's a two 18 person team so that one is examining, the other is 19 checking that the observations are correct and so forth.
20 So this is not just an individual that's 21 out there looking to see what might happen. Thi s is 22 all done as part of a documented observation by 23 qualified people.
24 MR. SHERMAN: Yes. We have an inspection 25 110 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and testing protocol that we call on for each document 1 plus a test method that we have.
2 MR. SCHULTZ: And your procedur es are 3 causing the team to document this examination in a 4 particular way.
5 MR. SHERMAN: Yes.
6 MR. SCHULTZ: So that when we look at the 7 reports or when anyone looks at the reports it was 8 mentioned earlier how do we know if the next generation 9 is going to know what happened when. This is the first 10 stage of that.
11 MR. SHERMAN: Correct. These will all 12 wrap up into a site visit report that is well documented 13 and the process is described in our test procedure and 14 in the ITP.
15 And that includes things about how y ou tier 16 and qualify inspectors. So there is basically a tiered 17 inspection program where you start off as almost as 18 a journeyman and then work your way up, you know, 19 apprentice work your way up to a journeyman to a senior.
20 MR. SCHULTZ: Appreciate that, th ank you. 21 MEMBER MARCH
-LEUBA: On this walk through 22 with procedure is it one time or is it going to be every 23 year? 24 MR. SHERMAN: These are all integrated.
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-3701 (202) 234-4433 You'll hear more, these are integrated into the overall 1 structural monitoring program. It's not as simple as 2 just, there's not one answer because it depends on the 3 severity. 4 There are multiple tracks. There are some 5 tracks that are for the routine observations and 6 measurements and there are other tracks, parallel 7 tracks that rela te to building analyses.
8 After the first time through actually 9 there's two parallel tracks. One that is based on the 10 results of the analysis, Said will tell us later on 11 about what we find, set some thresholds.
12 And there are other ones that are just part 13 of the overall parallel track that's for overall 14 monitoring. All right, next slide, please.
15 So the expansion measurements are done when 16 identified according to that methodology document.
17 These expansion measurements provide data that is 18 incorporated into the eventual evaluations.
19 If you think back to the earlier slides 20 on the overall testing program and Glenn's descriptions 21 of how we develop those load factors, this is the link 22 now. These expansion numbers are the link that 23 connects the actual plant to the results of the research 24 and the work done and to the statistical work that was 25 112 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 done to develop the load factors, right.
1 So the main group of these are direct 2 measures of expansion. Next slide. So we've seen this 3 already before. You've seen a little bit of some 4 background on the cracking index.
5 This is the most frequently used method 6 at Seabrook Station. Well over 100 locations are 7 currently being monitored with cracking indexes Glenn 8 just discussed in the background for the load factors.
9 As you previously heard about these are 10 measures of total cracking strain or a good way to 11 estimate total cracking strain to date. And it's 12 obtained from a crack mapping process where we do 13 quantitative measurements at individual cracks and 14 summation of crack widths along a set of lines.
15 I'll show an example of that in just a 16 moment. As we heard earlier this technique is based 17 on Federal Highway Administration documents that have 18 been developed for monitoring highway structures.
19 It's based on Institute of Structural 20 Engineer documents from overseas. It's a pretty well 21 established way of estimating crack strains.
22 These are used to estimate the expansion 23 reached to date by the ASR
-affected concrete. And this 24 is the primary data that drives the structural 25 113 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 evaluations.
1 You can see here we have an example of one.
2 We make these, they are an optical measurement with 3 a magnifying loop and with a calibrated, inside there, 4 there is an optical reticle that helps, that lets you 5 measure the crack widths under magnification.
6 So with this you can measure it out to about 7 two one thousandths of an inch. All right, next slide, 8 please. So just as a quick recap if we imagine how 9 these measurements are done, this is a quick recap if 10 we imagine there are some cracks in a piece of concrete.
11 Next click. We draw lines. For 12 simplicity I'm going to show you one line. We draw 13 one line on the concrete and we measure where the crack, 14 the width of the crack where it crosses the line.
15 If you do the one click. And then we sum 16 those numbers together, next click and divide by the 17 length of the line. Gives an indication of total 18 strain, how much that concrete has gotten bigger.
19 That's very simple. In practice, if you 20 give me a next click, this is what an expansion grid 21 at the station looks like. All right, so it's 20 inches 22 by 30 inches.
23 So we established that in the area selected 24 during the walk down. And we measure along each one 25 114 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 of those reference lines. The 20 by 30 inch grid size 1 is based on the Federal Highway Administration guide 2 document. 3 It lets us share those corner points to 4 economize the measurements and it balances the 5 directions pretty well. We get eight measurements in 6 one direction, nine in the opposit
- e. 7 To give you an idea of the effort required 8 each one of those is a measurement of the crack widths 9 there. This type of grid will take somewhere on the 10 order of an hour to an hour and a half for a person 11 to do. 12 You wanted an example. This cracking 13 level was about 1.2 millimeters per meter.
14 CHAIRMAN SKILLMAN: Let me ask this on the 15 prior slide, Slide 31. How do you select length, L?
16 MR. SHERMAN: It actually ends up being 17 ten inches to let us combine it with the mechanical 18 strain gauges. In just a moment I'll show you that.
19 We actually used the same grids to do the expansion, 20 direct expansion measurements and the optical 21 measurements.
22 So by combining with ten inches it lets 23 us do dual purpose on those grids and leverage the data 24 that we get optically.
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-3701 (202) 234-4433 MEMBER MARCH
-LEUBA: This is just 1 curiosity. Can you go to the next slide? When I look 2 at this picture I don't see cracks. I mean when I look 3 at the sidewalk I see cracks, I see air in between.
4 This is just filled in with calcium 5 silicate gel. Is that what it is?
6 MR. SHERMAN: So the dark, those cracks 7 if you could read the pieces most of those are on the 8 order of two thousandths of an inch to maybe five 9 thousandths of an inch, those individual surface 10 opening cracks.
11 And the dark appearing material is actually 12 the alkali silica gel itself. So that wall is dry.
13 That's not moisture. That's the alkali silica gel.
14 MEMBER MARCH
-LEUBA: I was reading during 15 lunch time. It's not alkali silicate. It's calcium 16 silicate. 17 MR. SHERMAN: Well it depends on what your 18 alkali is. Calcium is an alkali. That's an alkali.
19 It can be a sodium silicate gel as well. But we don't 20 have to go
-- 21 MEMBER MARCH
-LEUBA: I read the Wikipedia 22 page. It's very informative. So I know
-- 23 MR. SHERMAN: You can get different, the 24 cation can be different. It's the calcium or the sodium 25 116 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 which is that alkali Dr. Bayrak talked about.
1 MEMBER MARCH
-LEUBA: I recommend that you 2 read the Wikipedia page. That's the source of my 3 knowledge.
4 MR. SHERMAN: So if we jump to the next 5 slide please. So this is where the ten inch comes from.
6 So this is the mechanical strain gauges. So it's a 7 demountable mechanical strain gauge.
8 So we do these in addition to the cracking 9 index measurements. And we use the same monitoring 10 grid and we do this by installing those metal gauge 11 points, each gauge point has a receiver for the pins 12 from the mechanical strain gauge.
13 And what this lets us do is go to another 14 order of magnitude of accuracy.
This lets us go to 15 a ten thousandth of an inch.
16 MEMBER CORRADINI: So let me stop you here 17 because early I think in when NextEra was doing the 18 initial or maybe the MPR folks were doing the initial 19 thing there was a comment made th at the, I'll call it 20 the labor intensiveness is different between these two.
21 Can you tell me more about this? This one 22 strikes me as something I prefer to the sending a field 23 worker out to look at cracks. Is this just only 24 available in certain areas of, in terms of where you 25 117 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 can place the pins?
1 I'm trying to understand your choices 2 between these two because you made it a point of saying 3 that they kind of intermesh.
4 MR. SHERMAN: They intermesh. It's a 5 great lead in to where I was, they are very 6 complemen tary. The cracking index helps us get back 7 to the origin, to when we started, to before there was 8 any cracks, lets us know what's happened to date.
9 But there's a little bit, it's less 10 precise. Moving forward these provide more 11 information because now we have pins installed and it 12 lets us more precisely monitor expansion moving 13 forward. 14 And that's actually baked into the 15 structural analysis and into the structural monitoring 16 plan that we use CCI to start, lets us know where we 17 are. And then moving forward we combine it with the 18 enhanced accuracy of the expansion index.
19 MEMBER REMPE: So earlier I had asked well 20 how do you know where to put these pins in. And so 21 you would look at the prior slide and is it typically 22 where you see the bigger areas or more densely cracked 23 areas and you stick the pin in there or
-- 24 MR. SHERMAN: In general, yes, flip 25 118 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 forward one. You'll actually see in general, yes.
1 Remember I told you there's two tracks. You can see 2 here we have instrumented the wors t appearing area.
3 MEMBER REMPE: I can't tell that is, but 4 if it is, okay.
5 MR. SHERMAN: So that would be
-- 6 MEMBER REMPE: I might put it a little more 7 to the right and up a little based on the picture.
8 MR. SHERMAN: Remember you may not be 9 seeing the entire grid. So it depends. There's two 10 tracks. One track where we do track the worst areas 11 and that's because that lets, you can always find the 12 worst. 13 And then in some of the analysis, as Glenn 14 was describing we use moderate. So once, in the second 15 track that's the calculations looks for representative 16 areas, not necessarily the worst case because that feeds 17 into the analysis.
18 So there's two tracks. It's not, there's 19 a lot to it.
20 MEMBER RICCARDELLA: But if you go back 21 to your previous slide, do I understand that you have 22 put your pins at the intersections of these grid points, 23 right? You put one in the middle
-- 24 MR. SHERMAN: Yes.
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-3701 (202) 234-4433 MEMBER RICCARDELLA:
-- because you want 1 to compare them to the CCI. So they can only put them 2 there and there or there and there.
3 MR. SHERMAN: Right. You can see on the 4 slide it's Level E, across the middle E, F, G, and H.
5 Those are the individual pins. So those are much 6 faster to do.
7 The expansion index with the mechanical 8 strain gauge is much more, is faster and more accurate.
9 MEMBER RICCARDELLA: Yes, but you're only 10 looking at the increment which is a much smaller thing 11 that you're trying to measure.
12 MR. SHERMAN: Correct, right. So they're 13 very complementary.
14 MEMBER BALLINGER: But there's a temporal 15 nature to this as well. I mean the fact that you put 16 a gauge on something that looks ugly, that could be 17 an area for which you're already on the plateau.
18 How do you know that, it's kind of a, I 19 won't use the right terminology, crapshoot in terms 20 of how do you know that there isn't an area that's about 21 to become an issue?
22 MEMBER RICCARDELLA: But as I understand 23 it once you get beyond that plateau you've got to go 24 to the through
-thickness measurements. You don't keep 25 120 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 doi ng the in-plane measurements once you're on the 1 plateau, right?
2 MR. SHERMAN: Again, those are 3 complementary. And where would we, we would see 4 something and that's going to come into where Said talks 5 about how we group the areas.
6 So what would happen is i f cracks started 7 developing in a new area the classification of that 8 area would change. So then we would probably go and 9 have to go look and add monitoring.
10 The monitoring points are not static. We 11 add them as driven by the structural analysis we add 12 locations to fuel, again it's that cyclic process where 13 the field data feeds into and supports the analysis 14 and the analysis drives the field data.
15 Right, sometimes they may need an 16 additional data point so we will go and add another 17 d ata point.
18 MEMBER BALLINGER: So ten years from now 19 or ten years from x, there may be an additional, there 20 will likely be additional places where you start doing 21 measurements?
22 MR. SHERMAN: Yes. And that's all baked 23 into the structural monitoring program at the plant.
24 All right, next slide then and one more. We'll catch 25 121 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 back up. 1 We also heard earlier about 2 through-thickness measurements. These are also used 3 to measure ongoing changes and to verify that the 4 structure remains within the bounds, within tha t 5 playground that's established by the large
-scale 6 testing program.
7 Next slide. So deformation measurements.
8 We've talked, we've heard a little bit today about 9 deformation, right. All buildings are designed to 10 move. 11 If you walk out in this building you' ll 12 see joints in the, expansion joints where the buildings 13 are expected to move.
14 MEMBER RICCARDELLA: You went too fast.
15 MR. SHERMAN: I'm sorry.
16 MEMBER RICCARDELLA: So in all the, the 17 previous slide, please. All the slides up to this point 18 were CCI which as I understand it is related to in
-plane 19 expansion.
20 This is the only one where you're looking 21 at the through
-thickness which is where you have to 22 get to once you get above that .1 or .2 percent 23 threshold, right. We talked earlie
- r. 24 You said there are 26 buildings under 25 122 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 evaluation. I'm curious how many of those 26 have 1 forced you into the through
-thickness measurement 2 versus still doing the CCI measurements?
3 MR. SHERMAN: If those are all the 4 buildings that Said will bring up late r on that are 5 classified as Stage 3, Tier 3 sorry, I keep using the 6 wrong word.
7 MEMBER RICCARDELLA: So if you're going 8 to cover it later
-- 9 MR. SHERMAN: It's about 40 locations 10 where the through
-thickness measurements are done.
11 MEMBER RICCARDELLA: Thank you. 12 MEMBER REMPE: So I know there's a license 13 condition for additional data to corroborate what 14 you've seen. But what about this thing about adding 15 additional locations.
16 Is that something that's covered by one 17 of the regulatory programs that again, it's our job 18 to ask these kinds of questions, but to make sure the 19 licensee continues to be vigilant in looking for new 20 locations and adding additional monitors?
21 MR. SHERMAN: Yes, yes. That process of 22 adding data is worked into the m ethodology document 23 and it also comes out as a result of individual 24 structural reports.
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-3701 (202) 234-4433 So each structural evaluation has 1 requirements that roll out of that, that Said is going 2 to talk about that say how often you have to go back 3 and measure and where you have to do that.
4 MEMBER REMPE: Okay, thanks.
5 MEMBER RICCARDELLA: So continuing along 6 those lines. As I understand it your load factors, 7 your ASR load factors were based on measurements taken 8 so far and consider the scatter and, you know, the 9 standard de viation of those measurements.
10 It's possible that going forward in the 11 future that you might get some measurements that change 12 those distributions and result in a need to go back 13 and relook at your load factors.
14 MR. SHERMAN: Yes.
15 MEMBER RICCARDELLA: Is that, that's built 16 into the program?
17 MR. SHERMAN: Yes. Do you want to add 18 anything on that?
19 DR. BOLOURCHI: Up to now we have not seen 20 anything that changes by adding additional locations 21 that we have done. The distribution of dat a has not 22 changed. 23 And when we did those four zones we did 24 multiple distribution and anticipate this kind of 25 124 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 affect that three different distribution that if you 1 get more data one of those will cover it and all of 2 those distribution the envelope goes to ca lculate the 3 zone factor.
4 Therefore, the possibility is there. But 5 probability is not going to change.
6 MR. BELL: Without getting into a lot of 7 detail we took a, when we did the curve fitting to the 8 data to determine the load factors we did some 9 conservative adjustments to those data in order to 10 account for the possibility of more numbers and where 11 things might go.
12 So I think the scenario you pose is possible 13 but highly improbable.
14 MEMBER BALLINGER: In an earlier part of 15 the presentation somebody mentioned that the degree 16 of volumetric expansion of the components are, consists 17 of near the surface wider cracks, but fewer and as you 18 go into the surface, subsurface smaller cracks but more 19 of them. 20 I think I recall somebody saying that.
21 Now has the, have the measurements that you've done 22 on the internal part, the through
-thickness ones, have 23 they confirmed that contention?
24 In other words, can you convert the surface 25 125 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 to the interior and see if by measuring the interior 1 you're actually adh ering to that contention?
2 MR. SHERMAN: I haven't made the 3 correlation between the two. But I think you might 4 be, we expect the strain to be the same whether we have 5 a lot of little cracks and neither one of these methods 6 will really pick up or the throug h-thickness 7 measurement will not pick up how many.
8 It just measures total strain. So I can't 9 tell you if it's a lot of little ones or, you know, 10 one larger crack.
11 MEMBER BALLINGER: But what you're saying 12 is the strain is about the same?
13 MR. SHERMAN: I t hink that was what was 14 postulated earlier.
15 MEMBER BALLINGER: Postulated. Have 16 these measurements confirmed that?
17 MR. SHERMAN: I don't think we've done, 18 we have not done it.
19 MEMBER BALLINGER: Maybe I'm not using the 20 right terms.
But that was a contention that the strain 21 was uniform.
22 MR. BELL: There is actually a lot of 23 literature that says that the strain reduces with depth 24 from surface. So the surface measurements should be 25 126 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 conservative.
1 Do you have anything to add to that, Dr. 2 Bayrak? You have to go up to a microphone if you're 3 going to add.
4 MEMBER BALLINGER: So I must have 5 misheard. 6 DR. BAYRAK: So the description that I 7 provided in the morning relates to a study we have done 8 at Ferguson Lab where we sectioned a beam to tak e a 9 look at what the surface crack patterns look like and 10 what the whole thing looks like through the thickness.
11 So the strains remaining reasonably 12 uniform within the test specimens was based on that 13 observation.
14 MEMBER BALLINGER:
Okay, but what about 15 here? 16 DR. BAYRAK: So this particular 17 measurement is intended to measure how much the 18 thickness of a structural wall grows as opposed to how 19 the surface measurements which are in the x and y 20 directions vary as you move inwards into th e structural 21 wall. 22 So this is a z, direction measurement and 23 the cracks that we see on the surface provide an 24 indication for x and y strains.
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-3701 (202) 234-4433 MEMBER RICCARDELLA: Would the core 1 samples that you take out give you any information 2 regarding that?
3 MR. BELL: I'd like to make one clarifying 4 point on the statement that I just made. For in
-plane 5 strain in a reinforced member, reinforced concrete 6 member generally the strain is reduced with depth 7 because the reinforcement restrains the strain as you 8 go deeper into it. 9 MR. SHERMAN: Right. We would not 10 actually expect a match between the through
-thickness 11 because it's unrestrained and the in
-plane surface 12 strain. Those would not be expected to track together 13 because of the effect of restraint.
14 MEMBER BALLINGER: So there would be a 15 significant difference between the cover, what do you 16 want to call it, the concrete area that has no rebar 17 in it, the cover area, a couple inches or so and once 18 you get into the reinforced are a? 19 MR. SHERMAN: There is a difference. The 20 literature shows there is a difference. It's not giant 21 because the effect of the reinforcement is thrown to 22 a certain degree right.
23 And we're measuring in the same plane.
24 So everything that's in the same plane is there but 25 128 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 it's different than the through
-thickness. All right, 1 so we'll jump ahead to the deformation, starting on 2 deformation.
3 So to restart all buildings are really 4 designed to move, right. We do that intentionally.
5 We put gaps in buildings. We put thermal gaps in 6 buildings. We put seismic gaps in buildings.
7 So we do that to accommodate thermal 8 movement, earthquake and other such loadings, wind 9 movement. As such buildings incorporate specific, 10 back one, please.
11 We incorp orate specific detailing to 12 accommodate that movement, right. So in the field we 13 measure those deformations or movement of those 14 different structural components at those points of 15 movement and at other locations to provide more 16 supporting information for the analysis.
17 So in addition to that normal seismic or 18 thermal movements the ASR at Seabrook provides another 19 source of deformations, right, as the affected concrete 20 expands. It's just a difference source of movement.
21 Before going into our deformation 22 movements I want to take a quick detour. We alluded 23 to it this morning. We're going to talk about plant 24 construction for a moment.
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-3701 (202) 234-4433 Now if we jump to the next, right. So 1 Seabrook construction took place in excavated bedrock 2 which was near, the bedrock was v ery close to the ground 3 surface. 4 So after building the structures within 5 the excavated bedrock the remaining space at many 6 locations between the excavation face and the structure 7 was filled with unreinforced structural grade concrete, 8 right, of the same type used in the structures.
9 And they did it in two foot lifts. They 10 used that rather than a granular engineered fill.
11 Because this concrete is of the same type and 12 composition of the structural concrete that we've been 13 talking about so far there is evidence that it too is 14 undergoing ASR expansion, right.
15 This expansion creates pressures against 16 the backsides or underside of structures. You can see 17 how the structure is kind of worked into the bedrock 18 causing relative movements.
19 So we measured indicators of that movement 20 to be able to feed back into the structural analysis 21 that Dr. Bolourchi is going to talk about shortly.
22 Next slide, please.
23 So we measure the deformations of the 24 structures where applicable to provide information f or 25 130 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the analysis. For example, sometimes quantifying the 1 deformation pattern is critical to understanding the 2 performance and is required to support the analysis 3 as you'll hear about later on.
4 In a case such as this we'll measure the 5 deformed shape of the structure using a variety of 6 techniques. For example, when we were looking at a 7 vertical wall shown on the left we would mount, we put 8 a laser, a self
-leveling laser beam on the floor and 9 measure the offset to the wall in prescribed steps as 10 we go up. 11 Similarly we'll do the same thing on 12 horizontal surfaces with the horizontally projecting 13 laser. And in all those cases we would bring them back, 14 those measurements back to a known reference location.
15 Next slide, please. So simil arly, 16 sometimes we want to know information about the relative 17 position of buildings so that we can understand the 18 performance and to feed into the measurement analysis 19 and interpretation feedback cycle.
20 For example, we've heard a lot about fire 21 seal or the seals at seismic joints. That's what's 22 shown on the left here. That's a foam seal or a sealant 23 in a seismic joint.
24 So we measure and those are actually part 25 131 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 of the ongoing tracking program at the plant now. We're 1 measuring like 25 locations are routin ely monitored 2 plus there's other measurements that are done in support 3 of building specific evaluations.
4 So we look at those joint sealant 5 movements. Other places, there was a question earlier 6 about the space between the containment building and 7 the conta inment enclosure building. That's what you 8 see on the right.
9 I've spent many an hour in that space.
10 So they're measuring the distance between the two.
11 And again, because of the large size of these things 12 some of those, what sounds like a large deflection could 13 actually be a very small strain because they're just 14 large structures overall.
15 So we measure those spaces in between there 16 with a laser range finder. And next slide.
17 MEMBER KIRCHNER: Just to make that last 18 picture palpable , how much movement are you measuring?
19 MR. SHERMAN: In between those?
20 MEMBER KIRCHNER: Yes, and the annulus, 21 fraction of an inch?
22 MR. SHERMAN: Since we've started 23 monitoring they're small. This is one of the locations 24 where they had, this was where one of the missile shields 25 132 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 was that had to be cut back where a gap had actually 1 closed. 2 So it had been an initial gap that had come 3 into direct contact. The trick is here, Said is going 4 to show a picture. Remember these are very large 5 structures that are ve ry highly restrained.
6 So a very small amount of strain can 7 actually, gets kind of amplified by the shape of the 8 structure and where it goes by all the different 9 constraints on it. So we feed that right back into 10 the analysis.
11 That's why it's important to do these 12 measurements because it feeds into the analysis so we 13 can really understand what it is.
14 MEMBER RICCARDELLA: That missile shield 15 thing we're talking movements on the order of an inch, 16 inches, right?
17 MR. SHERMAN: Yes. Prov ided, again, we 18 don't know where it started. All we know is that it 19 was, it had come into contact, right. So we're assuming 20 that initial gap had been, was properly there which 21 is, I think, a valid assumption.
22 But again, very large structures, small 23 strains over large structures, yes. Without 24 necessarily a lot of stress associated with that. This 25 133 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 is a strain controlled phenomenon.
1 So you have to get into the strain world 2 in your head rather than stress world and that's hard 3 for a lot of people. Next slide, please. So we will 4 also occasionally undertake specialty testing in the 5 form of petrographic examinations when it's needed to 6 provide specialized information as was described 7 earlier in the large
-scale testing program.
8 This is done only in special cases where 9 we find a difference between the measurements, 10 observations and analysis. For example, this could 11 be a case where an indicated strain by the cracking 12 index really doesn't match with the appearance or the 13 pattern cracking and it doesn't match with what we see 14 in the results of the analysis.
15 There's a disconnect in our data. And we, 16 we're curious if that cracking is actually due to ASR.
17 So in that case we'll use petrography to see if the 18 source of that cracking is ASR or if another cause is 19 likely. 20 Next slide, please. So an example of the 21 process in this case, this is where the cracking index 22 suggests that actually a high degree of ASR. But that 23 was inconsistent with the overall pattern with what 24 we saw on the surface.
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-3701 (202) 234-4433 You know, we didn't see any of that ASR 1 gel. And it was inconsistent with the results of the 2 analysis. If we really had that much strain the 3 analysis showed us that other things should be happening 4 that weren't.
5 So we went back and this is actually in 6 th e pre-action valve structure. So we went in and 7 removed a core to test that assumption that all the 8 cracking was caused by ASR.
9 So we took a core centered at a surface 10 crack. Next slide, please. Then we take that core 11 out, cut it, polish it and perform a petrographic 12 examination on the core.
13 Petrographer is really a geologist who 14 studies concrete. They're specialist geologists who, 15 because concrete is just an artificial rock. So we 16 do that with two petrographers on site still un der a 17 full QA program.
18 We set up a temporary lab on site to do 19 that. And in this case we did the petrography and found 20 that the near surface cracking that was visible was 21 actually not due to ASR.
22 It's pretty clear the overall picture is 23 on the left. But on the right, it's hard in this room 24 to see, but it does not exhibit any of the typical 25 135 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 characteristics of ASR and the petrographers confirmed 1 there is no ASR in this core.
2 We don't see ASR gel formed. Usually you 3 would see it filling air voids and other cracks within 4 the concrete. We don't see that. The cracks do not 5 start in the aggregate and extend outward. They 6 actually run around the outside edge of the aggregates.
7 The aggregates themselves don't show signs 8 of reaction. We don't see any alteration rings. So 9 in this case we are able to find that the cracking was 10 not due to ASR. It was attributed to other locations.
11 So we don't have to account for it as an 12 ASR load. But we do track down where it came from.
13 All right, so next slide. So, I guess, in conclusion, 14 you know, we've gone through how we get the field data 15 and how it's used in support of the methodology 16 document, right.
17 It provides input data, a feedback loop 18 into the whole analysis cycle and information to support 19 that correlation of the work during the whole evaluation 20 cycle. And as another side, another track that it does 21 is the field data provides a means and is the basis 22 for a lot of the ongoing structural monitoring program 23 that goes on at the plant right.
24 The readings we're doing now have been 25 136 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 baked into the ongoing structural monitoring plan that 1 you'll hear about later on. All right. So with that 2 I think we turn it back to Said.
3 DR. BOLOURCHI: Okay, thank you. The goal 4 in here is to describe the structur al evaluation 5 methodology to define a procedure which is repeatable 6 and can be applied to all Category 1 structures.
7 And also there is another terminology we're 8 going to start using establishing a threshold limit 9 for potential futur e growth of ASR in each building.
10 And I will describe what does this threshold mean.
11 Is it building specific? And it is a 12 measure that we can expand the ASR still staying within 13 the limit of the defined code. Next slide.
14 All of you are well aware of whe re we are.
15 First, we started with the UFSAR and we have defined 16 an LAR. As part of the LAR we have attached to that 17 the load and load factor as a document and that's an 18 attachment to the LAR.
19 The material properties are per spec 20 defined in the original design per the larger
-scale 21 testing that was discussed in the morning. Also LAR 22 defined a creative approach and I will describe that 23 creative approach a little bit further on to that it 24 quite a bit of effort to evaluate all these structures 25 137 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 in a timely man ner. 1 Therefore, we tried to do it on graded 2 approach. And also we defined code supplement that 3 we will, the document five supplement to the code for 4 evaluation of this structure.
5 And we go through those specifically.
6 Then you come, the issue with the LAR is high level 7 and is not a repeatable, although it defined the process 8 but it is not detailed enough that can be defined, can 9 be repeated by sort of any other structural engineer.
10 Therefore, now we have defined a 11 methodology document and it is very detailed and is, 12 has three big segments. One is the analysis approach.
13 In that it will be, the requirement is to be a 14 repeatable process that can be applied for all Category 15 1 structures.
16 And also it defined a graded approach for 17 field data. Therefore, for different graded analysis 18 we will get conservative or more data as is needed.
19 And then the threshold limit is using the design margin 20 for the structure at the
-- right now to extend how 21 much more it has, that is still within th e code limit.
22 And that goes through the monitoring as 23 to, as it gets approached to that there will be proper 24 action to take place. And the next one is the finally, 25 138 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 structural evaluation.
1 And structural evaluation is the same 2 equation that you see from the first one. And 3 structural capacity defined by the code for all the, 4 any of the graded approach includes the reliability 5 inherent in the code.
6 The structural capacity should be greater 7 than all the load included in their structure, the ASR 8 load. When the structure is evaluated based on that 9 then we'll define the parameters that need to be tested 10 and the frequency of the testing and the requirement 11 of the trending.
12 And that will be defined in each of the 13 calculation packages. If yo u get any of the 14 calculation, Chapter 8 defined those things very 15 detailed on that, that can be taken directly from there 16 and put into the structural monitoring program which 17 has been in place.
18 And the last box is the structural 19 monitoring program that it is maintained completely 20 by the Seabrook plant. Next slide. Just to, since 21 the threshold is a new terminology that we are 22 introducing we try to use a similar equation that Glenn 23 discussed earlier.
24 On the left hand side it is the resistance 25 139 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 which we haven't changed. On the right hand side I 1 divided it in two terms. One, all the load effect that 2 is already in the UFSAR.
3 Therefore, we are not changing those. We 4 are not changing the load factors. All of them is 5 there, therefore, that is the sum of the fac tor designed 6 basis load that is there.
7 Then we have a factor of I, which is the 8 load factor for ASR. And then SA which is the load 9 factor load for the ASR. Then the last item which put 10 in green, KT edge, what we call the threshold factor. 11 Therefore, we go to the field and we measure 12 the ASR and the load by the strain, for example. We 13 put that thing as SA. We multiply it by a factor which 14 is always greater than one.
15 And it can be very high. In the end I'll 16 give you some summary on that. Therefore, we always 17 grade down one. One is the right at this present time.
18 If it is 1.5 it is 50 percent more than 19 whatever it is now. That is the only associated with 20 the ASR load because the other load is constant, is 21 not changing. Go ahead.
22 On the field data already we had a long 23 discussion. We always start with the walk down for 24 the observation. And we also define in detail in the 25 140 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 methodology document a graded approach for the field 1 data collection.
2 The reason that they will see the grade d 3 approach if a building has significant margin already 4 in it we try to do much simpler calculation. Keep a 5 lot of the conservatism.
6 As it is resolved we don't need as much 7 data. We can use more conservative calculations, a 8 lot mo re conservative for the, that and evaluate the 9 building. And also the typical data is all listed in 10 the methodology.
11 Therefore, this methodology is designed 12 such that the infrastructure need to reevaluated can 13 be done without any license change requiremen
- t. It 14 is all included in that.
15 Therefore, the in
-plane strain we talked 16 about CI, CCI and pin
-to-pin or expansion measurement.
17 And also changing in seismic gap, structural 18 deformation and structural distress like crack and 19 crack rate.
20 All of that has bee n accurately listed in 21 that on how it can be used. And also in, there is a 22 good section in the methodology that defines how do 23 you adjust what we measured in the field.
24 Does the table specifically define what 25 141 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 is ASR and what is not ASR? Therefore, you ca n go and 1 there are five different requirements to be ASR.
2 Therefore, that is defined.
3 But also there are other cracks that we 4 know that they are not ASR like pressurization. We 5 have data from 1980 that containing
-- we have the 6 pi ctures and the grade of where the crack was under.
7 The temperature affect differential ASR 8 between these structures have produced a structural 9 crack not an ASR crack and other sorts of structural 10 deformation. And if needed we'll do petrography to 11 identify if it is or is not because usually when we 12 go to a place then we can look at that.
13 And if it doesn't jive that all the, why 14 should it be ASR and we cannot completely identify it 15 based on the structural primarily on this lab on plate 16 -- lots of times we do petrography to confirm if it 17 is not ASR.
18 CHAIRMAN SKILLMAN: Dr. Bolourchi, would 19 it be acceptable if we took a 15 minute bio break because 20 the next portion of the presentation will be the graded 21 approach. This might be a clean break, give everybody 22 a few minutes to stretch their legs. Would that be 23 all right?
24 DR. BOLOURCHI: Absolutely.
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-3701 (202) 234-4433 CHAIRMAN SKILLMAN: Ladies and gentlemen, 1 we are in recess for 15 minutes. Please come back at 2 quarter past three by that clock.
3 (Whereupon, the above
-entitled matter went off the record at 2:57 p.m. and 4 resumed at 3:14 p.m.)
5 CHAIRMAN SKILLMAN: Ladies and gentlemen, 6 we are back in session, let's begin. To the presenters, 7 we're late in the day, we're behind schedule, I ask 8 you to take every acti on that you can to speed up this 9 presentation.
10 DR. BOLOURCHI: Okay.
11 CHAIRMAN SKILLMAN: We need time for the 12 staff, we need time for the public. We will go as late 13 as we need to go, but let's proceed forthwith. Thank 14 you. 15 DR. BOLOURCHI: Thank you. The ta lk about 16 the graded approach, next two slide, we go a little 17 bit slower, but after that, we'll try to go as fast 18 as we can.
19 In each of the building we start, we start 20 with the review in the field data and all the document 21 that there are, the original desig n document, review 22 all the Structures Monitoring Program to date, to figure 23 out if there was any observation over the life of the 24 plant. 25 143 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 And then, we do initial walkdown. And at 1 that point, we'll decide which space under how much 2 margin it is in the original design and what is the 3 status of the ASR and so on.
4 CHAIRMAN SKILLMAN: For those of you who 5 are on the phone line, please put your phones on mute.
6 Thank you.
7 DR. BOLOURCHI: Okay. Then, we will start, 8 we can start at any of the three stages of analysis.
9 Within all three stages, the commonality is that all 10 will be evaluated based on the code of record.
11 Therefore, in any of these three condition, 12 the conservatism inherent in the code will remain intact 13 for all of these stages and type of analysis.
14 MEMBER MARCH
-LEUBA: So, I can understand, 15 you call it the stages. Is that you're doing all three 16 for each component? Or are these options?
17 DR. BOLOURCHI: These are options and you 18 can start at any of them.
19 MEMBER MARCH
-LEUBA: So, it's an option and 20 you can choose one of the three for a component and 21 stay with it forever?
22 DR. BOLOURCHI: We can start with Stage One 23 and if you need to reevaluate it, I have a choice of 24 going to Stage Two.
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-3701 (202) 234-4433 MEMBER MARCH
-LEUBA: You do a Stage One, 1 if you don't meet the criteria, you go to Two, if you 2 don't meet the criteria, you go to Three?
3 DR. BOLOURCHI: But if a structure is 4 already in a more critical or as defined, we can start 5 at Stage Two. You don't need to go One, Two, Three, 6 we can go One, Three, if needed.
7 So, the Stage One is, obviously, the most 8 conservative calculation. These are usually we use 9 all the original design calculation, we don't do any 10 more recalculation of the demand.
11 Usually, the original design is done at 12 a part, the design stage very conservatively. And we 13 calculate the ASR in conservative way.
14 The way we do that, we go to the worse area 15 of the building and we measure that one. We amplify 16 that for the entire area. We expand that, if it can 17 take that load, ob viously it can take even if you have 18 more data in that.
19 We start with the most conservative way 20 of calculation, which is really over
-conservative, but 21 saves lots of time and has lots of margin in that.
22 Since it has lots of margin in this calculation, we 23 will mandate every 36 months going back and make sure 24 that nothing is changed in that.
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-3701 (202) 234-4433 The Stage Two is still very conservative, 1 because we still use all the original design 2 calculation.
3 All the loads which were calculated with 4 the original design, we don't touch it, we just go back 5 to usually in the old calculation, all that has been 6 done based on the closed form solution, very 7 conservative. They will pick up those very directly.
8 But usually, then, we will model the ASR 9 using finite element. And generally, that is the case 10 when the differential in the one area versus the other, 11 that difference between that, if you cannot simulate 12 by hand calculation, become more complex.
13 Or if the geometry is complex. If you have 14 a cylinder and a rectangle next to each other, trying 15 to estimate it by hand become very difficult.
16 In that case, we go to calculating the ASR 17 demand by the finite element, then we add to original 18 calculation and then, we will monitor it every 18 months 19 after it pass.
20 The Stage Three, which as I said, retain 21 all the evaluation based on the code, is the more 22 defined. We calculate
-- we develop a finite element.
23 And the first step in that would be to 24 correlate the finite element with the in situ condition, 25 146 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the sustained load at this point. And I have a figure 1 for that. 2 And then, we calculate all the loads, the 3 dead load, live load, lateral soil pressure, all the 4 load that we need in the original design and the ASR, 5 using that finite element. And then , we will monitor 6 these structure every six months.
7 If you go to next slide, this is a flowchart 8 for a Stage Three analysis, which is the most refined 9 one. The other one become simpler than that. We 10 started with Stage Three, either because we started 11 at that or it can come from the previous analysis.
12 Then, we will develop the finite element 13 and we correlate that to the field data that we will 14 talk, and I have a figure to represent that. And then, 15 we use, when the finite element model is validated, 16 then we will use it to calculate all the load, ASR and 17 non-ASR. 18 And then, we will amplify ASR load with 19 additional load, more with the threshold factor for 20 future growth of ASR. We calculate total load and then, 21 we come to the box at the junction.
22 The question is, is the capacity still 23 greater than the demand? Capacity, the core capacity 24 still. And the demand is all the load calculated.
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-3701 (202) 234-4433 If it greater than that, therefore, it meet 1 the licensing basis, as appended by LAR, which obviously 2 including ASR load, we define threshold limit and the 3 reference value for monitoring every six month.
4 If it doesn't pass, we have two choices.
5 Either we can go back and reevaluate with the same 6 methodology, how can we do it? Because if we can go 7 back and get more field data, we'll observe more 8 variation in the structure.
9 Or we can do petrography, if you have 10 assumed something is ASR and if it didn't qualify, we 11 can go back and do petrography and confirm it is not 12 ASR. If it is not, then we can go back an d reevaluate 13 this structure.
14 And that can happen if you approach the 15 threshold. Right now, we don't have that condition, 16 but it is anticipated in the methodology to be able 17 to do within that.
18 Or the other option, we can go and retrofit.
19 And we have already defined some retrofit and some 20 has been completed, that will be discussed by Seabrook.
21 Next slide, okay.
22 The model evaluation, model correlation, 23 corroboration with the field data is important step.
24 On the left
-hand side is the input that will go to 25 148 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 t he finite element. It is the CCI on the top left.
1 And as a Stage Three, the dot represent 2 the number of points that we have taken. As you see, 3 there is many points on that. Then, below that is the 4 pressure from the concrete backf ill. And then, all 5 the other load.
6 On the right
-hand side, we will get
-- we 7 have measure those, the deformation, either through 8 the seal or through the annulus measurement. And then, 9 we have amplified the deformation in order to be visual, 10 otherwise you don't see any deformation. And then, 11 we will try to match the deformation to that.
12 The only variable in here is the concrete 13 backfill, we can adjust, that we'll discuss, to match 14 that. Or in the other structure, it can be cracking 15 or cracking pattern or strain. And that is the output 16 and that the input.
17 One the comment that was in the morning 18 about the ASR, the CI value of the containment enclosure 19 to be small. We have the trending analysis with the 20 pin-to-pin measurement and we have looked at the slop e 21 of that versus the slope of the CI measurement, starting 22 from the early eighties to that value.
23 The change in the slope is insignificant, 24 therefore, the measurement that we have is valid for 25 149 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the evaluation of the CI. I mean, for the containment 1 enclosur e building. Next slide.
2 MEMBER RICCARDELLA: You don't have a plot 3 here that shows it, but it's saturated, you're saying?
4 It seems to have reached the level of threshold?
5 DR. BOLOURCHI: Well, your question, I 6 understood that you were saying that that is in the 7 low level and there may be a difference between the 8 measurement with the strain measurement versus the CI 9 measurement.
10 And I'm saying that we have, like, eight 11 years of pin
-to-pin, which is physical measurement that 12 describe on that, that it account for all the strain.
13 And when we get the slope of that and we 14 go back to the
-- go directly down, compare to the slope 15 if you started the CI all the way to the early eighties, 16 these two slopes are very similar to each other.
17 Therefore, that CI measurement that we use 18 for the containment enclosure building is 19 representative of the actual value. We have two ways 20 of confirming that value. Okay, next slide. Some of 21 the attribute of the
-- 22 MEMBER RICCARDELLA: Can you go back a 23 moment? 24 DR. BOLOURCHI: Sure.
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-3701 (202) 234-4433 MEMBER RICCARDELLA: So, the upper 1 right-hand corner, on a bigger version, I was trying 2 to understand you, this is, you're comparing your finite 3 element measure deformations to the actual measured 4 deformations.
I had trouble kind of interpreting which 5 -- 6 DR. BOLOURCHI: Oh, okay. The dark black 7 line is the
-- which is circular, that's the original 8 shape. 9 MEMBER RICCARDELLA: Okay.
10 DR. BOLOURCHI: Then, we put two circle, 11 inner and outer, each of them representing one inch 12 of deformation.
13 MEMBER RICCARDELLA: Yes.
14 DR. BOLOURCHI: Obviously, at 180, 160 feet 15 diameters, one inch, you will not see, but for 16 visualization.
17 Then, the dots are the actual measurements 18 that you see on the dots. And the lighter blue color 19 is the deformation presented by the finite element.
20 This at one section, we have done it at multiple 21 sections, to make sure that the deformation matches 22 the data on that. Okay?
23 MEMBER RICCARDELLA: Okay.
24 DR. BOLOURCHI: On the attribute , we are 25 151 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 using general purpose program ANSYS, which we got 1 license under the full QA and we have audited that and 2 we brought it under our QA program.
3 And that program has been used for multiple 4 other plans that we have used and others have used for 5 the industry. And the internal ASR is the ASR of the 6 reinforced concrete structures.
7 And for each of the finite element that 8 I showed at the previous slide, each of the element 9 consist of three elements. One representing concrete 10 and two representing rebar in o ne direction and two 11 orthogonal direction.
12 We expand the concrete by the CI 13 measurement and then, the reinforcement model will pull 14 it back and produce the pre
-stressing that was observed 15 in the testing program. Therefore, in here, we will 16 see the pre
-str essing that require to model on that.
17 And the concrete backfill is, obviously, 18 from the measurement that we have a bigger section, 19 all of which we defined.
20 MEMBER KIRCHNER: So, may I ask, do you test 21 your -- I'm looking at the sub
-b ullet there, on
-- I'm 22 interested how the nodalization might impact the 23 results. So, I assume you benchmark the code, with 24 the assumptions you just described, against the 25 152 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 large-scale test program beams?
1 Or how did you determine that the 2 nodalization used in the finite element method applied 3 here was actually doing physically what happens in the 4 structural member?
5 DR. BOLOURCHI: We have some hand 6 calculation that we can simulate that very easily.
7 And we have also used different method of calculation 8 and co mpared to that.
9 And the result
-- we also simulated some 10 of the testing that was done in response to some of 11 the question that was raised by NRC. We showed that 12 all of them are simulated properly.
13 MEMBER KIRCHNER: Like this morning, we saw 14 a large beam being flexed quite a bit. Were you able 15 to model that
-- 16 DR. BOLOURCHI: We did not
-- 17 MEMBER KIRCHNER:
-- behavior and failure?
18 DR. BOLOURCHI: We did not simulate that 19 particular one, but we have done the north wall of 20 Seabrook, for example, which has abo ut one inches of 21 deformation.
22 We have the CEB, which has plus or minus 23 two inch of deformation. And we have simulated those 24 and we match the actual field measure.
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-3701 (202) 234-4433 MEMBER KIRCHNER: Yes, but I can adjust a 1 code to get to the field me asurements. What I'm 2 thinking more is kind of a blind calculation of the 3 large-scale test program results, to have confidence 4 in the code as applied and that the nodalization is 5 sufficient to capture the effects, because the 6 properties are changing in the concrete mix and not 7 in the steel, other than, obviously, there's stresses 8 induced. 9 So, I'm just curious if you did some just 10 basic checks of the methodology, using the FEM code 11 against those test specimens from the large
-scale test 12 program. 13 DR. BOLOURCHI: We have not done a 14 validation against the test program. In our QA 15 program, we have done enough to confirm that it is done, 16 but we have not
-- if specifically you are saying that, 17 did we validate our program against large
-scale test, 18 we have not done tha
- t. 19 MEMBER RICCARDELLA: I thought you said you 20 did one. 21 DR. BOLOURCHI: Pardon me?
22 MEMBER RICCARDELLA: I thought you said you 23 did simulate one.
24 DR. BOLOURCHI: We have simulated some of 25 154 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the values on that
-- 1 MEMBER RICCARDELLA: On the large-scale -- 2 DR. BOLOURCHI:
-- and we have captured the 3 same delay cracking that was observed. We have 4 simulated that in the analysis. But we did not get 5 exact same dimensions.
6 MEMBER RICCARDELLA: If your ANSYS 7 analysis, it's a linear analysis?
8 DR. BOL OURCHI: ANSYS is for the
-- what 9 we have use is a linear analysis.
10 MEMBER RICCARDELLA: Linear, so if you were 11 simulating a test, you could only go up to the point 12 of first cracking?
13 DR. BOLOURCHI: That's all it is. I mean, 14 we have extended it for ourselve s to see with going 15 there. 16 But in our evaluation and modeling, we have 17 limited to the linear analysis, as required by the
-- 18 we did not extend to any nonlinear vein. We are not 19 getting to that range of large reflection that it was 20 tested. Okay.
21 The other factors, the structure cracking 22 and the cracking is associated
-- we have tied the 23 cracking to the strain in the concrete. Therefore, 24 any of the pre
-stressing has to be overcome. That 25 155 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 simulated delay cracking that was o bserved in the field.
1 Next slide.
2 This slide, we have seen before.
3 Basically, growth of concrete backfill can put load 4 on the structure. Let's go to the next slide.
5 In here, in the Methodology Document, we 6 have quite a bit of extension of discussion and that 7 here are coded basic concept of it. At any depth on 8 the concrete backfill, as it try to grow, will produce 9 a load, we assume a load equal to the overburden, is 10 all the load that is sitting up there.
11 And since if it want to grow beyond that, 12 it will grow vertically, doesn't need to grow 13 horizontally, is the direction of least resistance.
14 But when we want to simulate the deformation, we can 15 reduce that, like we have simulated in the CEB, we can 16 reduce that in order to match the deformation.
17 Or if we are not observe a crack on the 18 wall, we can assume that the pressure equal to the crack, 19 which is the conservative value. Therefore, when we 20 come to field observation, we say, go and make sure 21 there is no crack observed in the field. That's how 22 we adjust on that. Next slide.
23 The supplement on the code, there are five 24 supplement. The first one is, we add ASR load base 25 156 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 on the load and load factor, which were discussed, to 1 all the FSAR load. We are not changing FSAR load, we 2 keep all the load, we add the ASR to that.
3 And the second one is that we are accepting 4 the code calculated values as capacity for the 5 structure. And that is based on the large
-scale 6 testing. 7 The third one is, ASR produces compression 8 in the member and there is a terminology called shear 9 friction, that it is sliding of the concrete over each 10 other. 11 If you have compression, you have to 12 overcome the sliding friction. ACI 318
-71 does not 13 address that. All the other code beyond that, 14 including 83 version and ACI 3 49, address that 15 consistently. Therefore, we are using 318
-83, entire 16 section of that, instead of the original 71.
17 And the next two is reduction of the 18 structural property, because of the cracking. The 19 number four is full flexure, which ASME 443 and curr ent 20 ACI all recommend that, in lieu of doing a tedious 21 calculation, you can use a 50 percent reduction and 22 that's a conservative.
23 Because we want to get a higher value, this 24 is a displacement control, more stiff you put, more 25 157 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 load y ou going to get.
1 And the last one is axial and shear 2 reduction, because of the cracking. Again, the code 3 71 says, you can reduce it to zero. We gradually reduce 4 it in order to capture more load and that is standard 5 in the industry. Next slide.
6 The threshold parameters, this is specific 7 for each structure, for structure monitoring, after 8 we evaluate the building. But these parameters is from 9 a set of the well
-defined in the methodology.
10 Therefore, we are not coming up with a new 11 case, because if it come later they want to reevaluate 12 any of these building, the methodology already defined 13 what are the parameters that you can do.
14 And those are in
-plane expansion. As you 15 see, I'm not talking about CI anymore, it's just the 16 expansion. And the preferred method is the pin
-to-pin 17 expansion here. We also, we can look at the 18 deformation, seismic joint, or structure deformation 19 as included. Next slide.
20 In the summary, we have provided a 21 Methodology Document that includes how to include ASR 22 load and load factor to maintain inherent reliability 23 in the code.
24 And we provided repeatable graded approach 25 158 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 for analysis and collecting data, and also, threshold 1 values and limit that need to be monitored in future.
2 Therefore, as taken, is that the rep eatable analysis 3 process is for evaluation of all Category I structures 4 has been defined in here.
5 Next, we go to the next box in the 6 evaluation of the structure. Therefore, now, we use 7 the Methodology Document and apply to each of the 8 Category I structure
- s. 9 And in here, we going to define established 10 limit for the threshold and how much more these 11 structures have capacity to go. And again, the same 12 thing is, we are giving back to that the structure 13 capacity based on the code, it should be greater than 14 all the loads on that.
15 We go to next slide. For all Category I 16 structures that are being evaluated for the site, we 17 confirm that the structure meet the code of record and 18 we will determine the threshold for future ASR growth 19 and will define for each of them how often they need 20 to be monitored, based on the stage of the analysis 21 was done. 22 And we also defined the parameters that 23 need to be monitored. Also, we will identify if there 24 is an area of the structure that require enhanced 25 159 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 monitoring, which can be as short as two months 1 interval. And also, if there are some retrofit 2 required for the structure.
3 And a summary of the structure evaluation 4 is summarized in this table below. Obviously, it 5 doesn't add up to 26, I
-- 6 MEMBER RICCARDELLA: That was my question.
7 DR. BOLOURCHI:
-- can tell you right away.
8 Because what we have done is the number of structure 9 evaluation packages.
10 Some of the structures, we can combine them 11 together and evaluate it together. Some structures, 12 we had to do thre e or four different evaluations.
13 Like the example is manholes, there are 14 16 different manholes, different geometries, trying 15 to put everything in one
-- and some of them are Stage 16 One, some of them are Stage Two
-- become very difficult, 17 trying to stay wit h the structure.
18 Therefore, 19 of them is completed and the 19 threshold is from 1.2 to 3.7 for the ones which is 20 completed.
21 And out of the eight which is left, four 22 of them, one of them is Stage One, one of them is Stage 23 Two, two of them is Stage Three. We have the draft 24 calculation, but it is going through internal review 25 160 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 before we send it to Seabrook for evaluation.
1 MEMBER MARCH
-LEUBA: You might not know the 2 answer to this, order of magnitude, the equation that 3 controls this is capacity greater than the sum of the 4 loads, the load for the ASR, what's the percentage of 5 the total load?
6 DR. BOLOURCHI: It's very good question.
7 MEMBER MARCH
-LEUBA: And I know it depends 8 on -- each one is different, right?
9 DR. BOLOURCHI: Yes, each one is di fferent, 10 but there are places that ASR can be small, five
-ten 11 percent. There are places that the ASR can be 40 12 percent of the load.
13 MEMBER MARCH
-LEUBA: You've seen 40 percent 14 increase? 15 DR. BOLOURCHI: I have seen 40 percent and 16 there can be some structures that, in some direction, 17 there was not
-- doesn't produce load, but ASR become 18 primary load on that.
19 MEMBER MARCH
-LEUBA: But as a percentage 20 of the capacity, not a percentage of the total sum?
21 DR. BOLOURCHI: Oh, it could
-- 22 MEMBER MARCH-LEUBA: Because, I mean, if 23 you didn't have any load, then any load is a significant 24 change. 25 161 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 DR. BOLOURCHI: Right. I mean, as a 1 percentage, yes, because we always add up everything 2 to see how much is compared to the load that was design.
3 As a total load, probably about, could be about 30 4 to 40 percent. I mean, this is just an estimate. I 5 mean -- 6 MEMBER MARCH
-LEUBA: Relevant, it was not 7 a wasted exercise, we
-- 8 DR. BOLOURCHI: Yes, it is not
-- I mean, 9 I cannot say it one or two percent, it a value g reater 10 than that.
11 MEMBER REMPE: I'd like to understand 12 uncertainty and try and get a feel for it. Could you 13 go back to Slide 49, please?
14 DR. BOLOURCHI: Okay.
15 MEMBER REMPE: On the lower right, sometimes 16 the data are very
-- I assume the data are the little 17 dots or -- 18 DR. BOLOURCHI: That's correct.
19 MEMBER REMPE:
-- diamonds and
-- 20 DR. BOLOURCHI: That's correct.
21 MEMBER REMPE:
-- the predictions are the 22 line that are reddish
-- 23 DR. BOLOURCHI: Correct.
24 MEMBER REMPE:
-- colored. Some pla ces are 25 162 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 matching quite well, but then, if we look at towards 1 the end there, it looks like that it's almost 0.009 2 versus -- it looks like the data could be off by a factor 3 of two? 4 DR. BOLOURCHI: Well, okay, that's great 5 question. And if you look at that, i n the actual
-- 6 on the right
-hand side, if you look at the right
-hand 7 side on the top, we have different colors.
8 MEMBER REMPE: Right.
9 DR. BOLOURCHI: And that area that you are 10 referring to is the right
-hand side of that, which is 11 a special area, which is t he average of the
-- we have 12 actually input the average value between these two 13 locations. And that is the vertical direction that 14 was applied.
15 And the reason, because that value was very 16 high, either we can go and do a petrography and confirm 17 it's not there, but we will
-- at this stage, we say, 18 okay, let's have that, but we have, in that area, we 19 measured about eight or nine values and we put the 20 average of that eight or nine values into the model, 21 as a not constant value.
22 But when it comes with all the other load 23 combinations and the deformation, then the strain 24 deformation, it doesn't become constant, it become a 25 163 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 gradual value.
1 MEMBER REMPE: Okay.
2 DR. BOLOURCHI: But it is, as an input, it 3 is -- 4 MEMBER REMPE: Okay. So
-- 5 DR. BO LOURCHI: -- average. 6 MEMBER REMPE:
-- my takeaway, since I'm 7 not an expert in this, is if you see something like 8 that, you investigate it and try and understand and 9 get a better feel for what's going on
-- 10 DR. BOLOURCHI: Absolutely.
11 MEMBER REMPE:
-- at tho se locations?
12 DR. BOLOURCHI: Absolutely. And that is 13 exactly -- that was very important for us to do. For 14 that particular one, I know I spent at least about three 15 months. 16 MEMBER REMPE: I don't want to know what 17 you did for three months on it, but thank y ou. 18 MEMBER RICCARDELLA: Now, is that within 19 the scatter that we talked about from the mean to the 20 -- you talked about how you built the spread in the 21 data into the load factors for ASR.
22 Now, this one here, does that say that three 23 standard deviations is a factor of two or something 24 like that? Is that what that tells you?
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-3701 (202) 234-4433 MR. BELL: This is somewhat of an anomaly.
1 We're looking at the differences between an analysis 2 and a measured value.
3 MEMBER RICCARDELLA: Yes.
4 MR. BELL: And we ofte n will input a measured 5 strain, under the presumption that it's all ASR. And 6 what Said is saying is, if the model tells us there's 7 a large discrepancy there, then we need to chase down 8 why there's a discrepancy.
9 So, we'll either refine the analysis or 10 do petrographic analysis to explain the difference, 11 we just don't let it lie.
12 So, this isn't so much variation in field 13 data as the model not, at first blush, completely 14 describing the structural behavior. And then, we chase 15 that down.
16 MR. SCHULTZ: Said, you r last slide on 17 evaluation packages shows that there are three that 18 are in Analysis Stage, excuse me, nine that are in 19 Analysis Stage Three. And so, they're being monitored 20 on a six-month frequency?
21 DR. BOLOURCHI: Yes, after
-- they are on 22 a six months, after it is completed. The one that
-- 23 MR. SCHULTZ: Yes.
24 DR. BOLOURCHI:
-- it is completed, they 25 165 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 will go on a six months monitoring.
1 MR. SCHULTZ: How long does it take to do 2 these analyses?
3 DR. BOLOURCHI: Is about
-- 4 MR. SCHULTZ:
Roughly? 5 DR. BOLOURCHI:
-- five-six months, at 6 least. 7 MR. SCHULTZ: Are any in the augmented, you 8 mentioned augmented, could be less than six months, 9 are any of the completed package less than six months?
10 DR. BOLOURCHI: Actually, in the 11 Methodology Document, we have provisions, if there is 12 an area that may require retrofit, then we will put 13 it on a higher monitoring
-- 14 MR. SCHULTZ: But you don't have that for 15 these -- 16 DR. BOLOURCHI:
-- until we -- 17 MR. SCHULTZ:
-- completed packages?
18 DR. BOLOURCHI:
-- it is r etrofitted and 19 the issue goes away.
20 MR. SCHULTZ: I see where that fits, thank 21 you. 22 MEMBER MARCH
-LEUBA: But the monitoring, 23 what you do is, you check the cracks again every six 24 months, to make sure that they're below a threshold?
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-3701 (202) 234-4433 Yo u don't rerun the analysis?
1 DR. BOLOURCHI: That's correct. That's 2 correct. 3 MEMBER MARCH
-LEUBA: So, and we were told 4 a single location takes about a couple of hours to 5 perform? 6 DR. BOLOURCHI: That's correct. And when 7 we get to the monitoring, there's a
-- our preferred 8 method is the expansion measurement, which most 9 difficult time is to get to the location. The actual 10 measurement is very fast, usually
-- 11 MEMBER MARCH
-LEUBA: I have not read that 12 slide yet, but suppose you give the threshold in units 13 of CCI change instead of 1.2, that doesn't mean much 14 to the guy in the field.
15 DR. BOLOURCHI: Oh, yes. No, no, no, we 16 will define exactly for one
-- 17 MEMBER MARCH
-LEUBA: The maximum CCI is 4.7?
18 DR. BOLOURCHI: Right. We will define as 19 one value or at one location or aggregate, depending 20 on the deformation pattern, aggregate of that, and will 21 give them the actual value.
22 And also, if it is Stage One, we reduce 23 that by 90 percent, and if it is a Stage Two, we reduce 24 it by 95, and so on.
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-3701 (202) 234-4433 MEMBER MARCH-LEUBA: I'm just thinking, 1 human factors, everybody in that table understands what 2 a load effect S sub A means. The tech you're going 3 to send in the field doesn't know what that is.
4 DR. BOLOURCHI: No, that
-- 5 MEMBER MARCH
-LEUBA: They don't know what 6 CCI is. 7 DR. BOLOURCHI: That's correct. We give 8 the actual value of, this much strain cannot go more 9 than this value. We give the exact value in the table.
10 MEMBER RICCARDELLA: So, when you say the 11 threshold factor range from 1.2 to 3.7, can I assume 12 that the 1.2 is associated mainly with the ones in Stage 13 Three and the 3.7 would be way down in the Stage One?
14 Is that -- 15 DR. BOLOURCHI: That's usually
-- there's 16 one or two building which has 1.2 and is Stage Three.
17 The other one, we have 1.4, 1.7, 2, 2.5, and it can 18 be -- there is one building that is 1.3 and by design, 19 we set it on that.
20 That it is a Stage One, because doing any 21 higher evaluation doesn't change. But as a part of 22 the methodology, we
-- 23 MEMBER RICCARDELLA: But 1.2 means -- 24 DR. BOLOURCHI:
-- put that value
-- 25 168 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MEMBER RICCARDELLA:
-- you're 80 percent 1 of the way there, if you can only take 20 percent more 2 expansion before you hit the limit?
3 DR. BOLOURCHI: Before you hit the limit 4 and -- 5 MEMBER RICCARDELLA: Have you to do so? 6 DR. BOLOURCHI:
-- you can do the 7 reevaluation or there are specific procedure how to 8 get there. Either you
-- because usually not all the 9 structure get effected, there is a small part of the 10 structure that you can either reevaluate or retrofit.
11 MEM BER RICCARDELLA: Retrofit?
12 DR. BOLOURCHI: Yes.
13 MEMBER RICCARDELLA: I see.
14 DR. BOLOURCHI: It is option that we can 15 -- will be discussed by Seabrook.
16 MEMBER DIMITRIJEVIC: I have a risk related, 17 I'm risk specialist, so I really appreciate all of this 18 deterministic evaluation. But, from my point, so, you 19 basically prove that they satisfy licensing basis and 20 capacity of the structure.
21 What I would like to understand is there 22 any, because I know you do this and you will understand 23 it well , is there any risk implication of this?
24 So, let's say that we have a Seabrook 25 169 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 station, same for Westinghouse, on the same seismic 1 area. I'll just ask about seismic, I will ask when 2 this second group comes about other failure modes.
3 So, you have same seismic event and you 4 calculate fragility for the components and structures.
5 Would the Seabrook, with this issue, with ASR issue, 6 would the fragility numbers be different?
7 DR. BOLOURCHI: I haven't calculate the 8 actual fragility calculation for you, but we hav e -- 9 MEMBER DIMITRIJEVIC: What's your feeling?
10 DR. BOLOURCHI: No, no, let me
-- 11 MEMBER DIMITRIJEVIC: Okay.
12 DR. BOLOURCHI:
-- each of our calculation, 13 I am a seismic engineer
-- 14 MEMBER DIMITRIJEVIC: Yes, that's right.
15 DR. BOLOURCHI:
-- by nature, we have 16 calculated all the calculation, original calculation 17 is done by the stick model for the seismic and we review 18 all of that.
19 The total mass is not changed, obviously.
20 The center of gravity, center of the
-- we calculate 21 the center fragility and central mass for each of the 22 structures, to make sure the original stick model still 23 is valid. 24 Therefore, the original calculation in 25 170 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 which Seabrook, I assume that they have done the PRA 1 work, would not be impacted on that. And
-- 2 MEMBER DIMITRIJEVIC: But, for example, you 3 said that there is a change in seismic gap. This can 4 impact the impact of the one structure and that is
-- 5 so, you think really that ASR would not impact any risk, 6 seismic risk calculation?
7 DR. BOLOURCHI: No, no, we calculate 8 actually the maximum calculated value for what is the 9 required seismic gap? And we calculate that, I know, 10 on a very conservative way.
11 Originally, they did all the seismic gap, 12 they put everything at three inches. And most of the 13 calculations are less than half an inch, that you 14 require. 15 We are recalculating those to confirm, at 16 an area that was abutting against each other, that was 17 one of our recommendation, because it would impact the 18 seismic, original seismic evaluation.
19 Therefore, we recommended to cut the 20 missile shield and they did cut it and the requirement 21 was to have at least one inch of gap and to maintain 22 that, to maintain the same code requirement and also, 23 the fragility that would impact on that.
24 MEMBER DIMITRIJEVIC: Th ank you. So, no 25 171 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 risk implication, that's what you're saying, right?
1 This phenomena doesn't have a risk implication 2 whatsoever?
3 MR. BELL: Maybe a way to address your 4 question at a higher plane, if this is appropriate, 5 we could go through the analysis and all the processes, 6 the structural performance, including fragility, would 7 be in line with a code
-compliant structure.
8 MEMBER DIMITRIJEVIC: All right.
9 MEMBER RICCARDELLA: I believe you did the 10 analysis using the original design
-basis response 11 vector for SSE
. 12 I'm sure you're probably aware that the 13 updated response vector, as part of the Central and 14 Eastern United States Seismic Study, showed a 15 considerably reduced response vector, in the one to 16 ten hertz range. I'm sure you're probably aware of 17 that. 18 DR. BOLOURCHI: I think Seabrook did the 19 PRA work already?
20 MR. BROWNE: Yes, I would have to reach out 21 for the PRA work.
22 MEMBER RICCARDELLA: Well, I'm just saying 23 that might be some additional margin that you could 24 take -- 25 172 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 DR. BOLOURCHI: Ye
- s. 1 MEMBER RICCARDELLA:
-- advantage of in
-- 2 DR. BOLOURCHI: We have additional margin.
3 MEMBER RICCARDELLA:
-- the event that you 4 have the 1.2, an issue with the 1.2.
5 MR. BELL: The exercise here was to check 6 conformance to the original design criteria. To the 7 extent that was conservative, that's built into the 8 present exercise.
9 CHAIRMAN SKILLMAN: Let's move along, 10 folks. 11 DR. BOLOURCHI: Okay, next slide.
12 Therefore, in conclusion, we have evaluated or we are 13 completing evaluating all seismic Category I struc ture 14 using the consistent methodology applicable to all of 15 them. 16 And we provided the threshold for each 17 building that we will complete. Therefore, and defined 18 action require to make sure each structure meet the 19 code of record. And that conclude our part of the 20 evaluation.
21 CHAIRMAN SKILLMAN: Thank you very much.
22 Members, before we release this team of consultants, 23 have you any questions, please? Hearing none, it's 24 -- Ron, go ahead.
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-3701 (202) 234-4433 MEMBER BALLINGER: What's the uncertainty 1 on the 1.2? 2 DR. BOLOURCHI: Generally, the
-- I know 3 some of these buildings by heart now. Some of the 4 buildings that is 1.2 is on the conservative side, I 5 can very easily, if I do more evaluation on that, can 6 easily, because the controlling part is low grade and 7 that's why we limited to above grade, and we
-- easily, 8 we have more margin. We have tried to be conservative 9 on this evaluation.
10 MEMBER BALLINGER: So, it's better than 1.2?
11 DR. BOLOURCHI: It's better than 1.2.
12 MEMBER BALLINGER: Not lower than 1.2?
13 DR. BOLOURCHI: No.
14 CHAIRMAN SKILLMAN: Okay. Where are we on 15 presentations? Do we have another presentation from 16 -- 17 MR. BROWNE: Mr. Chair, we have a short, 18 I'll call it a short presentation on the program, but, 19 I'll talk to Ed, but I t hink in the
-- there's several 20 slides at the backside of this next section that involve 21 the license amendment that I think would be redundant 22 and I think the Subcommittee likely understands the 23 construct of that.
24 But I'd advocate we at least walk through 25 174 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the program a bit with Mr. Carley and Ms. Hulbert, and 1 then, we'll turn it over.
2 CHAIRMAN SKILLMAN: Absolutely. Let's do 3 that and let's get moving. Thank you. Please go 4 ahead. 5 MR. CARLEY: Thank you. I am Edward Carley, 6 the Engineering Supervisor for Li cense Renewal and 7 I was part of the project team for the resolution in 8 the licensing basis for ASR
-affected concrete 9 structures.
10 As our final segment for today, we will 11 discuss the approach for managing the aging effects 12 of ASR-affected concrete structures at Seabrook 13 Station. If we can just go ahead one slide?
14 Ms. Jackie Hulbert will provide the details 15 of our enhanced Structures Monitoring Program and ASR 16 monitoring implementation. And as we had just 17 discussed, we will probably j ust skip over the summary 18 of our current licensing actions, as we've discussed 19 those quite a bit today. So, just two more slides 20 ahead. 21 So, referring back to the graphic you've 22 seen throughout this presentation, the Structures 23 Monitoring Program takes the bounding conditions of 24 the large-scale test program and the threshold 25 175 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 monitoring limits from the structural evaluation and 1 implements an overall ASR Aging Management Monitoring 2 Program that is integrated into the site's 3 comprehensive Structures Monitoring Program. 4 As shown by this graphic, the
-- if and 5 when limits are approached or a new condition is 6 identified, there is a feedback loop to update the 7 structural evaluations. And as shown on the graphic, 8 the program currently implemented will continue into 9 and through the period of extended operation.
10 And on that, I'll turn it over to Ms.
11 Hulbert. 12 MS. HULBERT: Hi, I'm Jackie Hulbert. I'm 13 the Structures Monitoring Program Engineer at Seabrook.
14 As Ed had mentioned just a second ago, w e 15 have developed a comprehensive Structures Monitoring 16 Program that addresses the typical Maintenance Rule 17 portion, as well as the identification, evaluation, 18 and monitoring of alkali
-silica reaction affected 19 concrete structures and associated systems, 20 str uctures, and components.
21 Our Structures Monitoring Program 22 incorporates the results and the respective monitoring 23 limits from both the large
-scale testing program, as 24 well as the structural evaluations.
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-3701 (202) 234-4433 In addition, Seabrook Engineering, we have 1 performed both interdisciplinary and 2 cross-disciplinary training on ASR and ASR
-induced 3 building deformation to bring awareness to the Station.
4 We have developed web
-based training for 5 all badge personnel onsite, as well as we provide 6 focused training for department
- s. Next slide.
7 So, I know this slide's busy, and the next 8 slide will be as well. The intent is not for you to 9 be able to read every word.
10 So, at Seabrook, we developed a database 11 in which we enter all of the deficiencies, the 12 monitoring results, et cetera, that derive from the 13 inspections performed in accordance with our Structures 14 Monitoring Program.
15 The database mimics the different sections 16 of our program. As you can see, we have the Maintenance 17 Rule portion, ASR expansion moni toring, the ASR
-induced 18 building deformation monitoring, and equipment 19 impacted by building deformation, and groundwater 20 monitoring.
21 The database we use as a tool or an aid, 22 that we use to track our monitoring results, and in 23 addition, the other department s onsite have access to 24 this, so they can use this for their information. Next 25 177 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 slide. 1 Like I said, this is busy. This just gives 2 you a glimpse of what's included in our database. It's 3 a partial view of all the observations identified under 4 the different sections of our program.
5 This is particular to our residual heat 6 removal vaults. Examples captured in our program 7 include, like, corrosion of the steel components, 8 concrete cracks, ASR, degraded building seals, 9 coatings, et cetera.
10 So, the margin parameters in acceptance 11 criteria for ASR
-affected concrete structures are 12 driven by the results from the large
-scale testing in 13 the structural evaluations, as previously mentioned.
14 Expansion due to ASR is tracked via 15 in-plane expansion measurements, in th e form of either 16 combined cracking index or pin
-to-pin. 17 The through
-thickness expansion is tracked 18 via material testing in the installation of the borehole 19 extensometers. And then, we also track volumetric 20 expansion.
21 The limits for ASR expansion, like I said, 22 were derived from the large
-scale testing program.
23 The monitoring frequency is driven by the severity of 24 the in-plane expansion.
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-3701 (202) 234-4433 In-plant expansion measurements are 1 performed either on a six
-month or a 30
-month basis.
2 Through-thickness expansion measurements are 3 performed on a six
-month basis, as well as the 4 volumetric.
5 The parameters to be monitored for 6 structural deformation due to ASR are building
-specific 7 and their associated thresholds are derived from the 8 structural eval uations. 9 Examples of parameters in which we monitor 10 can include the measurements of seismic gaps between 11 structures, the annulus width measurement between our 12 containment structure and containment enclosure 13 structure. We do plumbness measurements, in
-plan e 14 expansion measurements. We sound for drumming areas.
15 And a slew of other things.
16 The monitoring frequency for the 17 deformation parameter monitoring is based on the stage 18 in which the building was analyzed under.
19 So, as previously mentioned, Stage One 20 structures are monitored every 36 months. Stage Two 21 structures are monitored every 18 months. And Stage 22 Three are monitored every six months.
23 Additional conservatism has been 24 implemented by our Structures Monitoring Program, by 25 179 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 way of applying what we call an administrative 1 monitoring action limit, and that's applied to the 2 threshold limits that were developed through the 3 structural evaluations.
4 The admin limit provides time to perform 5 additional inspections, to ensure limits are not to 6 be approached prior to the next inspection interval, 7 and to initiate corrective actions if warranted.
8 In addition, the Structures Monitoring 9 Program ensures that if a new deficiency is noted or 10 if a deficiency worsens that could potentially have 11 an impact on structural evaluations, that it is entered 12 into our Corrective Action Program and evaluated 13 appropriately.
14 So, monitoring locations. As previously 15 mentioned, we monitor ASR expansion volumetrically, 16 both in-plane and through
-wall. 17 We currently have a total of 136 locations 18 in which we monitor in
-plane expansion, as it relates 19 to the large
-scale testing, and we have an additional 20 21 grids established that derive from the building 21 deformation evaluations.
22 Thro ugh-thickness expansion, like 23 previously mentioned, is determined by establishing 24 what the expansion is to
-date and then, using the 25 180 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 borehole extensometers to track any potential expansion 1 going forward.
2 To establish the expansion to
-date, we 3 extracted concrete cores, performed material testing, 4 and correlated the results back to the large
-scale 5 testing program.
6 We currently have a total of 48 7 extensometers installed in various structures and we've 8 taken approximately 200 cores and performed material 9 testing on all of them.
10 As mentioned before from MPR, we test all 11 cores for compressive strength and for modulus of 12 elasticity.
13 Actually, Seabrook
-- so, for the material 14 testing, Seabrook actually brought the capability to 15 test cores onsite. We set up a lab tha t mimicked the 16 lab at the Ferguson Structural Engineering Laboratory.
17 And we developed procedures in accordance 18 with the respective ASTM standards for the obtaining 19 and the performing of the material testing on the 20 concrete cores.
Next slide.
21 The monitoring locations and parameters 22 related to the structural deformation, like I said, 23 are derived from the structural evaluations and are 24 captured in our program.
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-3701 (202) 234-4433 This slide shows some examples of the 1 monitoring we performed. Top left ph otograph shows 2 how we perform seismic gap measurements between 3 structures.
4 Top right is, we have these plastic 5 Avongard crack gauges installed on specific cracks 6 throughout certain structures, to monitor any 7 additional crack width or worsening of said cracks. 8 We also monitor in
-plane expansion, like we mentioned, 9 via both CCI and the pin
-to-pin. 10 And we measure, like I said, between 11 structures, like the bottom right, the annulus between 12 the containment enclosure building and the containment 13 structure.
Next slide.
14 With our ongoing monitoring, we have 15 established that the current ASR expansion levels are 16 within the large
-scale testing limits and our 17 structures and the associated building deformation 18 monitoring parameters are within threshold limits 19 established from the structural evaluations.
20 As we had mentioned before, ASR expansion 21 at Seabrook is slow. We have been monitoring expansion 22 since 2011 and our monitoring frequencies are 23 sufficient to ensure that the limits are not appr oached 24 prior to the next inspection interval.
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-3701 (202) 234-4433 MR. SCHULTZ: Jaclyn, how much margin do 1 you have on that statement? In other words, you know 2 it's not going to happen before the next inspection, 3 but if it did happen then, I mean, it would be nice 4 if you had two intervals, comfort level for at least 5 two intervals.
6 Because a reevaluation, for example, could 7 take six months, it was stated. Action take to correct 8 an issue that was identified and then, inspection, could 9 take even longer. So, how
-- 10 MS. HULBERT:
Correct. With
-- 11 MR. SCHULTZ:
-- much margin do you have?
12 Do you feel, with the slowness and
-- 13 MS. HULBERT: That's a loaded question.
14 MR. CARLEY: So, not getting back into what 15 we discussed in the closed session, right now, the 16 in-plane limit is at, the highest location is 2.46.
17 So, significantly lower than the overall limits.
18 Volumetric is at 0.78, so if you can 19 remember the close limits, but significantly lower.
20 So, even in our worst case situations, we still have 21 quite a bit of margin to all areas.
22 MEMBER RICCARDELLA: That's for the first 23 bullet, relative to the large
-scale testing. It seems 24 to me, the second bullet is the more limiting.
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-3701 (202) 234-4433 MR. CARLEY: The more
-- the threshold 1 limits are our limiting case.
2 MEMBER RICCARDELLA: Like that 1.2, have 3 you had multiple measurements on the one that has the 4 threshold factor of 1.2, to see how that's progressing?
5 MR. CARLEY: That is the CEB, and that is 6 the one that we have the most data on. And 7 particularly, on seismic gaps, and we see very little 8 to no -- 9 MEMBER RICCARDELLA: Can you
-- 10 MR. CARLEY:
-- movement on that.
11 MEMBER RICCARDELLA: Okay.
12 MR. CARLEY: Liying can probably elaborate 13 on that, because she takes those measurements for us, 14 if you need more detail.
15 MS. HULBERT: But like I said, we have this 16 admin limit that we apply to it as well, to give us 17 more time to react.
18 MEMBER MARCH
-LEUBA: But I don't know how 19 to compare that 1.2, which is a 20 percent margin on 20 the load factor, which is a threshold, how to c ompare 21 to how much cracks you can have. Can you double the 22 number of cracks and it still be okay on that?
23 Twenty percent doesn't seem like that much 24 margin, but it may be more than sufficient, because 25 184 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 it's in the wrong units. And I have no idea how to 1 co nvert it. 2 MEMBER RICCARDELLA: It depends on how fast 3 it's changing. I mean, if they've taken measurements 4 in the last three six
-month intervals and it's only 5 gone from maybe 1.1 to 1.1, then you're not too concerned 6 about reaching 1.2.
7 MEMBER MARCH
-LEUBA: But what I'm hearing 8 on the top bullet units is that for 30 years, it has 9 grown 2.5 millimeters. And it can
-- they can tolerate 10 seven. 11 MEMBER RICCARDELLA: Yes.
12 MEMBER MARCH
-LEUBA: So, that
-- over there, 13 you don't have a problem. What I don't know, how to 14 compare 1.2 to something in those units.
15 MEMBER RICCARDELLA: Yes. It probably 16 depends on the structure.
17 CHAIRMAN SKILLMAN: Let's move. Something 18 to think about in your program.
19 MR. SCHULTZ: Another question was, it 20 sounds as i f Seabrook has taken over all of the 21 inspection, Seabrook personnel are doing all the 22 inspections that were done by
-- 23 MR. COLLINS: No, SGH has continued to
-- 24 MR. SCHULTZ: Their work?
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-3701 (202) 234-4433 MR. COLLINS:
-- perform those inspections.
1 We do have a long
-range pla n, because SGH is not cheap, 2 sorry you guys. So
-- 3 MR. SCHULTZ: No, I understand that.
4 MR. COLLINS: We do have
-- we have just 5 opened up three positions in our design group, civil 6 design group, to hire in individuals to
-- and SGH has 7 just said they'll he lp train these individuals to do 8 the work that SGH is now performing. We intend to have 9 a transition to bring all those activities in
-house. 10 MR. SCHULTZ: Is there a clear qualification 11 program that is required to do this kind of inspection?
12 MR. COLLINS: We'll set up a qualification 13 program. I know SGH has their own qualification 14 program, that's something we're going to have to go 15 through the transition period with.
16 MR. SCHULTZ: Okay, thank you.
17 MR. CARLEY: ACI 349 - 18 MR. SCHULTZ: Okay, good.
19 MR. CARLEY:
-- has the requirements.
20 MR. SCHULTZ: Thank you.
21 MEMBER REMPE: Remind me, what is the admin 22 limit, what percent of the
-- 23 MS. HULBERT: Ninety
-seven percent.
24 MEMBER REMPE: Ninety
-seven, so it's only 25 186 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 three percent addi tional margin?
1 MS. HULBERT: But this is on top of the 2 conservatism that's already built into the model.
3 MEMBER REMPE: Thank you.
4 MEMBER DIMITRIJEVIC: May I ask a question?
5 Why do we worry about those small details if there 6 is no risk implication of that?
They just told us it 7 doesn't change any risk, so why we are so concerned 8 of is it 1.2 or 0.9? What is going to change from the 9 risk perspective?
10 MR. SCHULTZ: Maybe if you go to Slide 18, 11 if you're ready to do that. I mean, there are 12 modifications that a re happening to the facility 13 because of this program. And they're determined based 14 upon the analyses and the inspections.
15 CHAIRMAN SKILLMAN: Vesna, it goes back to 16 the design basis. This is an issue where the licensee 17 must demonstrate that the loads imposed by ASR, combined 18 with other loads, do not exceed the licensed load 19 limits. 20 And so, while there might not be any 21 significant risk implications, there is most certainly 22 a license implication. And this is very much a licens e 23 demonstration of loading capacity, so that the facility 24 is within the bounds established by its license.
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-3701 (202) 234-4433 MEMBER KIRCHNER: But, Dick, it's more than 1 that. I mean, if they exceed the limits from the codes, 2 then you can't make assumptions about success of the 3 particular structure to withstand, let me just pick 4 on one of the inputs, seismic loading, if you don't 5 meet code within the margin that's required.
6 So, it does turn back to a risk impact, 7 because then, when you do your PRA, you pretty much 8 need to assume that with that load and that degradation, 9 that piece of equipment does not meet its function.
10 It becomes very important with seismic Cat I components 11 and structures.
12 MEMBER DIMITRIJEVIC: I understand this, 13 but what I'm saying, this is just setting limits, 14 triggering limits. We are not anywhere close not to 15 meet -- okay. 16 MEMBER REMPE: So, earlier
-- 17 MEMBER DIMITRIJEVIC: I'm a probabilistic 18 person, I'm staying out of this discussion.
19 MEMBER REMPE: Well, earlier today, you 20 asked, have they reevaluated fragility? And in my 21 mind, I was wondering, have you gone through and thought 22 about what seals, other seals due to building 23 deformation, might be impacted?
24 And has a similar type of analysis been 25 188 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 done on that? I mean, it's not just fragility, it's 1 penetration seals, and has that been carefully thought 2 through all the way?
3 MR. CARLEY: Yes. And seals are inspected 4 as part of our monitoring program, along with seismic 5 gaps, fire seals, we're looking at those and make sure 6 -- 7 MEMBER REM PE: All of them?
8 MR. CARLEY: Yes, those are all incorporated 9 into our Structures Monitoring Program, as part of 10 structures monitoring, but also as part of the 11 deformation review, to verify that those seals are 12 staying intact through
-- 13 MEMBER REMPE: So, you're monitoring the 14 deformation that could impact all those
-- these kind 15 of questions are good. I appreciate it, just because 16 it would be hard to divine that from what we were given 17 to read in advance.
18 MEMBER DIMITRIJEVIC: Well, I was going to 19 go in more details, like the electrical vaults or the 20 pipe vaults and things. But then, I said, if they're 21 not impacted in seismic area, there is nothing else 22 which will impact it.
23 Not any other challenge, or maybe they will 24 -- so, this was why I concentrate only on the seismic 25 189 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 demand versus the others. So, I mean, there is so many 1 different failure modes can be introduced here, but 2 if they are not going to fail under seismic, then
-- 3 MR. CARLEY: Yes, and I think the tru e 4 answer, as Chairman Skillman indicated, as long as we 5 stay in our limits, our licensing limits, there is no 6 increased risk. I mean, that's what we're looking at.
7 CHAIRMAN SKILLMAN: Let's move on, we're 8 almost there, let's go.
9 MR. CARLEY: If it's all rig ht with 10 everyone, we'll skip over the review of the license 11 amendment and the license renewal application and move 12 on to Slide 15.
13 This is just the summary of our closure 14 of the open item from 2012 in the SER, for Structures 15 Monitor ing Program.
16 We've updated to augment the existing 17 Structures Monitoring Program by the addition of 18 plant-specific Alkali
-Silica Reaction and Building 19 Deformation Aging Management Programs.
20 And we've also added a tie in our IWL 21 Program to our Structures Mo nitoring Program, to 22 address ASR.
23 CHAIRMAN SKILLMAN: Okay.
24 MR. CARLEY: And as our conclusion, NextEra 25 190 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 has implemented a program that effectively evaluates 1 and manages the aging effects of ASR on affected 2 concrete structures and associated components.
3 And on that, I'll turn it back over to Mr.
4 Collins for conclusions.
5 MR. COLLINS: Thanks, Ed. Next slide, 6 please. So, you'll recognize the flowchart from my 7 opening discussion of the background of ASR at Seabrook 8 Station. 9 We have presented a detailed discussion 10 on each aspect of the graded approach that has been 11 developed in response to the identification of ASR in 12 our seismic Category I concrete structures.
13 The flowchart explains the integrated 14 approach that NextEra Seabrook ha s developed. All 15 ASR-related efforts fit together and all results, 16 conclusions, lessons learned, are all incorporated 17 ultimately into our Structures Monitoring Program.
18 Next slide.
19 And then, these are the 19 structures that 20 we have completed a seismic Category I structural 21 evaluations. Listed under the actions required on the 22 right-hand column are activities moving forth for 23 retrofit for areas that are outside the limits or bounds 24 of the analysis, and we are taking appropriate actions 25 191 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 in those cases.
1 MEM BER MARCH-LEUBA: Before you move to the 2 next one -- 3 MR. COLLINS: Sure.
4 MEMBER MARCH
-LEUBA: -- I understand you 5 will be coming back next month, I believe, for the full 6 Committee, to get our coveted letter. I would ask you 7 a favor. 8 If you can present this s lide to us again 9 and add an extra column, which is the percent 10 contribution to the load by ASR? Because those 1.2s 11 at the bottom look really bad, but maybe the ASR only 12 contributes five percent to it.
13 If it's not too much work, whi ch I mean, 14 you have the numbers, I would add how much did
-- what 15 was the contribution of ASR to that threshold?
16 MR. COLLINS: I don't see that as being 17 unreasonable, we'll work on that.
18 MEMBER MARCH
-LEUBA: It would help me a lot, 19 understand how relevant AS R is to this problem.
20 MR. COLLINS: Understood, thank you.
21 MEMBER MARCH
-LEUBA: And if you could send 22 it -- if you have it done three days in advance, don't 23 send it the night before at midnight, so we can read 24 it. 25 192 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. COLLINS: We'll work through it to make 1 s ure you have reasonable time to review the information.
2 But next slide, please. Again, this is a conclusion 3 statement, to rack up, close up the discussion for 4 today. 5 In conclusion, NextEra has completed a 6 comprehensive effort to c onduct large
-scale testing 7 to understand the structural implications of ASR, 8 developed methodology for evaluation of ASR
-affected 9 structures, evaluated ASR
-affected structures to the 10 degree I just showed you in the previous slide, and 11 have developed monito ring strategies for ASR
-affected 12 concrete and associated systems, structures, and 13 components.
14 Completed structural evaluations 15 demonstrate seismic Category I structures comply with 16 the licensing basis, as amended by the LAR. We've shown 17 that ASR progressi on is slow.
18 Ample margin exists before large
-scale 19 expansion limits would be approached. Monitoring 20 frequency are based on relative margin to the limits 21 and thresholds.
22 And our efforts provide reasonable 23 assurance that the structures will continue to perf orm 24 their intended function, consistent with the licensing 25 193 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 basis, again, as amended by the LAR, through the period 1 of extended operation.
2 If there's no more questions, this will 3 end our presentation for today.
4 CHAIRMAN SKILLMAN: Okay. So, colleagues, 5 any question or questions at this point for NextEra 6 or either of their consultant teams?
7 MEMBER KIRCHNER: What is, I don't see it 8 here in the rack up, in the summary, how does the 9 containment margin, how would you, not demonstrate, 10 in your -- as a result of yo ur program and your analysis, 11 what would you say about the containment?
12 You've got threshold factors for all these 13 seismic I categories
-- 14 MR. COLLINS: That
-- 15 MEMBER KIRCHNER:
-- that CV, is that the 16 1.8, there?
17 MR. COLLINS: Yes.
18 MEMBER KIRCHNER: Is that it?
19 MR. COLLINS: That's correct, sir.
20 MEMBER KIRCHNER: Okay, thank you.
21 MEMBER RICCARDELLA: And the CV, I don't 22 see in this table.
23 MR. COLLINS: Sorry?
24 MEMBER RICCARDELLA: I'm sorry, I don't see 25 194 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the -- 1 MEMBER KIRCHNER: It's down her e, I think, 2 there. 3 CHAIRMAN SKILLMAN: It's about six from the 4 bottom. 5 MEMBER RICCARDELLA: Okay. All right, 6 thank you.
7 CHAIRMAN SKILLMAN: Colleagues, any other 8 questions for
-- 9 MEMBER MARCH
-LEUBA: Yes, to remind me, the 10 containment is the one that almost didn't have any ASR?
11 So, that's where the percentage I'm asking you will 12 help, because you will see no difference before and 13 after. I hope.
14 MR. COLLINS: We'll apply that to all the 15 items I have listed here.
16 CHAIRMAN SKILLMAN: Okay.
Going once?
17 Going twice? NextEra and MPR, and the team from Boston, 18 thank you very much.
19 Not being trite, we've saved the best for 20 last. We've got the NRC staff to come up and they've 21 been patient all day long.
22 We did take a break an hour ago. I'm go ing 23 to ask that we move into the next phase of the 24 presentation. And if individuals need to disappear 25 195 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 for a few minutes, would you please do that, but let's 1 keep this meeting going, because we really would like 2 to wrap up at a reasonable hour. Please.
3 MR. DONOGHUE: Yes, Chairman Skillman, I'll 4 tell you that the staff, embracing transformation, has 5 looked through its slides
-- come on up, come on up 6 -- and will streamline as they can, but we're ready 7 to answer all the Subcommittee's questions.
8 CHAIRMAN SKILLMAN: Thank you, Joe. So, 9 Angela, are you the leader today?
10 MS. BUFORD: Yes.
11 CHAIRMAN SKILLMAN: Thank you. Let's just 12 hold for a minute here. Ladies and gentlemen, let's 13 get started. Angela, are you ready?
14 MS. BUFORD: Yes.
15 CHAI RMAN SKILLMAN: Yes, ma'am.
16 MS. BUFORD: Okay. There we go.
17 CHAIRMAN SKILLMAN: Let us begin.
18 MS. BUFORD: Okay, great. My name is Angela 19 Buford. I am a Structural Engineer in the NRC's Office 20 of Nuclear Reactor Regulation. I'm also the technical 21 lead for the Seabrook license renewal ASR issue.
22 Seated with me at the table are Bryce 23 Lehman, he is another Structural Engineer in NRR. And 24 also, Nik Floyd, who is a Senior Reactor Inspector in 25 196 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Region I. 1 Also at the table is actually George 2 Thomas, who won't have a speaking role today, but he 3 participated in the review of the license amendment 4 request. 5 Like Joe said, in the interest of time, 6 we're going to trying to streamline what we say and 7 not repeat some of the information that was already 8 given to you.
9 But as it relates to the staff's 10 impressions and our review, some of the information 11 may overlap, just so that you can get a feel for our 12 reactions and our actions.
13 As you guys know, this issue has definitely 14 evolved over time. I've actually been involved since 15 day one, so that's eight years.
16 And a lot of iterations of the LRA were 17 not deemed sufficient by the staff, because we weren't 18 able to come to a reasonable assurance conclusion, 19 because there was testing being done, there wa s not 20 enough information, and we weren't able to have 21 confidence that ASR would be effectively managed.
22 After extensive work by the licensee and 23 extensive review from the staff, we are now able to 24 have that reasonable assurance conclusion and can now 25 197 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 close that open item. Next slide, please.
1 This slide just presents an overview of 2 what we'll be discussing today. So, I don't need to 3 read it. But I'll just begin with the overview and 4 then, I'll turn it over to my colleagues.
5 Oh, you know what?, this is But ch's 6 presentation, if you just scroll through? Okay, there 7 we go. Because this is what we'll be covering. And 8 again, we'll try to pare down as necessary. Next slide.
9 I will just highlight that, because ASR 10 is a complex phenomenon and it's the first identified 11 in the nuclear industry in the U.S., the NRC assembled 12 a large team of individuals to help coordinate and 13 evaluate the issue, and that's including the 14 organizations that are up on that slide.
15 It's the Seabrook ASR Issue Tech nical Team, 16 and we've had extensive coordination in assessing and 17 sharing information along the way. Next slide.
18 So, a lot of this slide is history, so 19 unless you have any questions on it, I will skip through 20 to the next. We know how ASR was found and th at 21 operability determinations were developed. Okay.
22 So, again, on this slide, NextEra covered 23 most of why ASR occurred. But I will highlight the 24 last bullet, that the Seabrook Health Monitoring 25 198 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Program for Systems and Structures, which was a 1 precursor to the Structures Monitoring Program, which 2 is required by the Maintenance Rule, did not then have 3 a process for periodic reassessment to assure that all 4 failure modes were identified and monitored.
5 Since then, NextEra has adopted ACI 341.3R, 6 which includes guidance for monitoring all aging 7 effects for concrete, including active cracking, such 8 as ASR. 9 CHAIRMAN SKILLMAN: I would like to just 10 make an observation, as I've been preparing for this 11 meeting for about six or eight weeks.
12 What I finally tumbled to, when I was 13 thinking about 50.65, Maintenance Rules, Structures 14 Monitoring, and all of the experience I have had, I 15 was asking myself, how did this slip through the crack?
16 And the answer that I'm comfortable with, 17 whether it's a good a nswer or not, is, this is an active 18 element of a passive component.
19 And we normally don't think about a passive 20 component having an active mechanism that has the 21 potential to degrade that component to the point where 22 it is no longer within its design basis
. 23 So, at least in my own mind, in an attempt 24 to not point fingers or create fault or to suggest 25 199 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 anything untoward, this one slipped by a lot of people 1 in the whole industry.
2 This isn't just something that happened 3 in a little corner of New Hampshire, this could have 4 slipped by anybody. But it does raise the question, 5 are there any other passive components out in our realm 6 that have an active element that we're not looking at?
7 And I don't know the answer to that 8 question, but
-- well , we know about NVT, we know about 9 all kinds of chemical issues, but here's truly one 10 that's a sleeper. It's really under everyone's radar.
11 But it just strikes me that a unique feature 12 of this is, here is a passive component that has an 13 active mechanism w ithin it, and none of us saw it coming.
14 MS. BUFORD: Yes.
15 MR. DONOGHUE: Chairman Skillman, this 16 isn't really an answer to your question, but I'll just 17 emphasize that the staff plays close attention to 18 operating experience. I know the industry does.
19 And one of our jobs in the Division of 20 Materials and License Renewal, they were put together 21 for a reason, because a lot of those degradation 22 mechanisms are material based, material engineering 23 based. 24 So, we are paying attention to operating 25 200 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 experience, that's ho w we think we're going to catch 1 them as early as we can.
2 CHAIRMAN SKILLMAN: Good, thank you, Joe.
3 Not philosophizing, I just
-- I found it important 4 to communicate that, because in a way, it tells me, 5 this is how we got here. This really snuck up on 6 everybody.
7 MS. BUFORD: Yes, and it actually happened 8 during the review for license renewal, so that was a 9 focused review, specific to that application.
10 Under the reactor oversight process 11 requirements, NextEra performed an extent of con dition 12 review and prompt operability determinations and 13 concluded that, from a regulatory standpoint, the 14 affected structures were operable, but degraded, and 15 nonconforming, because ASR was a degradation mechanism 16 that was not taken into account in the the n current 17 licensing basis.
18 The prompt operability determination 19 analyses assumed that the Seabrook design equations 20 remained valid for concrete affected by ASR and used 21 a reduction in capacity for structural limit states 22 such as shear and compressive stren gth. 23 Regional inspectors and Headquarters 24 experts reviewed the operability determinations. The 25 201 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 NRC staff concluded that the analyses used conservative 1 load factors to ensure that there was sufficient 2 engineering margin.
3 Secondly, i nspectors and experts from 4 Headquarters performed field walkdowns and confirmed 5 that there were no significant indications of 6 deformation, distortion, or rebar corrosion.
7 Third, that the ASR was localized and was 8 occurring slowly, based on existing operati ng 9 experience. And then, finally, the degradation was 10 being monitored.
11 And those operability determinations are 12 still in place and are being resolved under the license 13 amendment request.
14 In response, NextEra made commitments to 15 address the issue of ASR
-affected concrete and to 16 confirm those commitments, the staff issued a 17 confirmatory action letter, or CAL.
18 The CAL referenced NextEra's planned 19 large-scale testing program and you heard about that 20 a lot today.
21 At the time that the applicant was 22 proposing the testing program, they wanted to define 23 crack limits for ASR and to examine ASR behavior in 24 a structural context, as opposed to an unreinforced 25 202 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 core bore samples.
1 Under the license renewal process, in June 2 of 2012, the NRC staff iss ued its safety evaluation 3 report with open items. The document discussed the 4 Seabrook operating experience related to the impact 5 of ASR and included one open item related to the need 6 for ASR to demonstrate that the aging of structures 7 would be adequately managed during the period of 8 operation, extended operation, despite ASR.
9 The Region, during its inspection 10 procedure, 71002 Inspection, came to the same 11 conclusion. And such that the NRC staff did not find 12 that the structures could be effectively managed for 13 the aging effect, given the proposed monitoring.
14 Shortly after the SER with open items was 15 issued, NextEra supplemented it's license renewal 16 application to include a plant
-specific ASR monitoring 17 program. 18 This was also the time frame that the SAITT, 19 the technical team, was formed to allow for effective 20 alignment of Agency positions. Next slide.
21 As discussed previously, NextEra's prompt 22 operability determination evaluations used a 23 conservative loss of structural capacity.
24 The NRC, with input from an ind ependent 25 203 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 expert on structural engineering, independently 1 verified that there was reasonable assurance that the 2 ASR-affected structures at Seabrook maintained 3 adequate margin to continue to perform their intended 4 functions.
5 However, since the prompt operability 6 determination evaluations were based on conservative 7 estimates and literature data, the staff understood 8 that NextEra would be initiating a large
-scale testing 9 program to determine the actual impact of ASR on the 10 performance of the structures.
11 The NRC, as part of its CAL review, reviewed 12 those plans, and also under the license renewal review.
13 There was a significant amount of back and 14 forth, with the NRC staff asking questions and holding 15 public meetings to understand how the testing program 16 was going to be credited to analyze the structures.
17 Next slide.
18 So, there was a difference in opinion.
19 NextEra viewed the large
-scale testing program as more 20 of a research and development effort, to gain 21 information that would help to inf orm monitoring 22 programs. 23 The NRC position, however, was that if the 24 testing would be used to support the position that ASR 25 204 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 did not have a structural impact, then this would be 1 a new method of evaluation for the current license that 2 would need to be approve d by the NRC.
3 Similarly, the staff position with respect 4 to license renewal has always been that if the testing 5 program would be the basis for elements of Aging 6 Management, then that would require a detailed review 7 by the NRC.
8 So, in response, NextEra submitted their 9 license amendment request that included the large
-scale 10 testing program and would amend the Seabrook licensing 11 basis to include the findings of that large
-scale 12 testing program. Next slide.
13 So, you already know that dur ing routine 14 walkdowns in 2014 and 2015, it was NRC Resident 15 Inspectors that observed degraded seismic and fire 16 seals that appeared to have been caused by differential 17 movement between adjoining concrete buildings.
18 It was determined that ASR caused this 19 add itional aging effect through cumulative 20 micro-cracking in ASR
-affected structures. In 21 addition, there was discrete large cracks and the 22 effects were not anticipated. They were identified 23 by the NRC as a different consequence of ASR.
24 In addition, the larg e-scale testing 25 205 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 program did not address specifically how building 1 deformation would affect the ability for structures 2 to perform their intended functions.
3 Therefore, NextEra subsequently developed 4 an additional plant
-specific Aging Management Program 5 called the Building Deformation Monitoring Program, 6 to manage this effect.
7 I'll just add that, based on your earlier 8 comments, Mr. Chairman and Dr. Corradini
-- 9 MEMBER REMPE: I'm short, but I'm right 10 here. 11 MS. BUFORD: Oh, I'm sorry, Remp e, Joy, 12 excuse me. Okay, yes, right. Yes, I couldn't see you.
13 Sorry about that.
14 MEMBER REMPE: Otherwise, we look a lot 15 alike. 16 (Laughter.)
17 MS. BUFORD: Sorry about that, Ms. Rempe.
18 So, I just wanted to add that, based on your earlier 19 comments about the length of time that it's taken from 20 the initial review to get to this point, part of the 21 reason that the staff was not able to reach a reasonable 22 assurance conclusion was our concern that NextEra did 23 not appear to be addressing the potential for ASR to 24 mani fest in other ways.
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-3701 (202) 234-4433 So, we didn't have confidence, throughout 1 this process, that monitoring plans that were in place 2 would manage the aging effect in a more holistic manner.
3 MEMBER REMPE: So, that clarifies a question 4 I was going to ask about, this was not anticipated.
5 It sounds like the staff did do some homework and 6 recognized that this could be another effect, because 7 it's in the literature.
8 MS. BUFORD: I think that it definitely came 9 to -- it was a surprise, I think, even to the staff, 10 although in the literature, it does say that ASR can 11 manifest itself in other ways.
12 It's just that that particular way of the 13 building deformation hadn't been identified by the 14 licensee. And it was of concern to the NRC that it 15 was the NRC that id entified the issue.
16 CHAIRMAN SKILLMAN: Let me ask this, as I 17 listen to your words and think about what we've learned 18 today, it's logical from my perspective, as a long
-term 19 plant person, I'd be looking at buildings, I'd be 20 looking at what the Maintenance Rule would tell me to 21 look at, but the last thing I would be thinking about 22 is that the engineering fill or the concrete that was 23 outside the building was actually imposing a load, 24 causing the building to deform.
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-3701 (202) 234-4433 That would never have crossed my mind.
1 Is that -- when you say, NextEra really didn't latch 2 on to the fact that the buildings were being deformed, 3 as an individual in PE, I'd say, well, I probably would 4 have missed that too.
5 I never would have thought that there would 6 be outside forces that were strong enough to shift my 7 building. Is that kind of what's hiding in here?
8 MS. BUFORD: Well, yes, but I think that 9 our reaction really was that, because if you
-- we walked 10 down the plant numerous times. And if you go to the 11 areas, it's clear that something's wrong, right?
12 You've got expanded
-- 13 CHAIRMAN SKILLMAN: Something's off?
14 MS. BUFORD: Right. So, I guess, our 15 concern really was that people
-- this has been 16 potentially going on for years and no one noticed it.
17 So, even if you couldn't predict the 18 backfill to be expanding the structures, it was a little 19 bit just -- it was surprising to us that, walking the 20 plant, no one said, why is that seismic gap smushed?
21 Or isn't that supposed to be three inches, 22 and that looks like it's actually just hitting the other 23 building? So, those kind of symptoms, we were
-- it 24 was surprising that those symptoms weren't identified 25 208 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 sooner, really, I think.
1 CHAIRMAN SKILLMAN: I see. Okay, thank 2 you. 3 MS. BUFORD: Okay. This is really already 4 -- you can turn to the next slide, please. This 5 information has already been covered, just that in 6 August of 2016, the license amendment request was 7 submitted to resolve the licensing basis.
8 And also, to provide technical inputs to 9 the lic ense renewal review. The review of the 10 methodology and the large
-scale testing was needed in 11 order to come to a reasonable assurance conclusion for 12 license renewal.
13 And so, the staff's review under the 14 license amendment request provided that technical 15 rev iew. 16 And now, I will turn the presentation over 17 to Nik Floyd, who will discuss the Regional inspection 18 and oversight.
19 MR. FLOYD: Thank you, Angie. Good 20 afternoon, everyone. My name is Nik Floyd and I now 21 will discuss the Regional inspection and oversight of 22 ASR at Seabrook, which I have been personally involved 23 with since 2013. Next slide.
24 The roles of the Regional inspections were 25 209 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 initially focused on NextEra's structural assessments 1 of the reinforced concrete buildings affected by ASR. 2 As you heard in some of the previous slides, 3 NRC performed independent reviews to verify that the 4 affected structures were capable of performing the 5 required safety functions and were properly 6 characterized as operable, but degraded and 7 nonconformi ng. 8 We have continued to perform semiannual 9 inspections to review the Structures Monitoring Program 10 implementation and results and to verify the 11 significant changes, if any, are evaluated for impact 12 on the concrete structures.
13 One of those sensitivities wa s the fact 14 that this was initially mis
-unidentified and then, the 15 identification of building deformation led us to 16 another increased sensitivity, that we need to continue 17 to look at this with a keen eye.
18 The Resident Inspectors also provide 19 insights on new material conditions in the plant, which 20 I'll describe later.
21 In addition to the onsite monitoring, the 22 NRC performed inspections of NextEra's large
-scale 23 testing program, to ensure that the results were being 24 appropriately reflected in the operability ass essments 25 210 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 and evaluations of ASR
-affected structures.
1 The Regional Office has lead the Seabrook 2 ASR Issues Technical Team, as the team's chair. Part 3 of that role has been to ensure a coordinated effort 4 between the Regional inspector s and Headquarters 5 technical staff, when conducting inspections, as well 6 as assisting in some of the technical licensing review 7 audits. 8 We provide insights and observations from 9 each inspection to the NRC inspectors and experts on 10 that team.
11 The Resident I nspectors, who are also at 12 the plant each workday, also participate in these 13 meetings. 14 It was really this collegial knowledge 15 sharing that's led to a comprehensive oversight and 16 has aided the staff during the licensing activities 17 related to ASR.
18 And a lot of that has also included requests 19 for additional information as new issues arise. Next 20 slide. 21 There have been thousands of direct 22 inspection hours by Regional inspectors and 23 Headquarters structural experts related to ASR at 24 Seabrook since 2010.
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-3701 (202) 234-4433 In total, the combined number of 1 inspections at Seabrook and the Ferguson Structural 2 Engineering Laboratory, which is the location of the 3 large-scale testing program, is 32 weeks.
4 Just to note, these figures do not include 5 the separate audits conducted by Headquarters as part 6 of the licensing review activities.
7 The scope of the Regional inspections 8 consisted of reviewing the operability determinations, 9 the confirmatory action letter team inspections, 10 Resident Inspector samples specifically looking at ASR, 11 as well as the semiannual onsite inspections focused 12 on the ongoing monitoring and corrective actions for 13 ASR. Next slide.
14 Since 2010, the Regional inspections have 15 focused on NextEra's performance to fully identify 16 the effect s of ASR on Seabrook structures, to evaluate 17 the condition with sufficient technical detail, and 18 to resolve the nonconforming condition.
19 We have closely monitored NextEra's 20 response to ASR, from the initial identification during 21 the petrography of concrete samples to the 22 implementation of ongoing corrective actions, which 23 would include enhancements to the onsite monitoring 24 programs. 25 212 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 I'll now discuss a few of those key 1 observations from this experience.
2 During the NRC's initial oversi ght of ASR 3 at Seabrook, the inspectors identified concerns 4 regarding the long
-term operability of the structures 5 affected by ASR.
6 This was understandable, because the 7 various characteristics of concrete affected by ASR 8 and the related effects on other elem ents of the 9 structure, such as rebar, due to groundwater 10 in-leakage, and also the progression rate of ASR at 11 the site, were not well understood.
12 Several early inspection findings related 13 to inadequate operability determinations, to fully 14 evaluate the ASR i mpact with available information.
15 It was really this long
-term impact concern 16 that led to a public meeting with NextEra staff and 17 to the NRC subsequently issuing a confirmatory action 18 letter, with one of NextEra's commitments being a time 19 line of resolution of actions and plans to conduct a 20 large-scale testing program.
21 Just a quick note, I'll provide
-- 22 MR. SCHULTZ: Excuse me, just to clarify, 23 this leads back then to the statement on the previous 24 slide that all of the ten noted short comings were all 25 213 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 low significance or very low significance, is what you 1 represented there.
2 And so, that was the earlier finding and 3 then, as time went on, it was determined that this really 4 is a long-term programmatic problem that needs to be 5 seriously con sidered. 6 MR. FLOYD: Yes, that would be correct.
7 So, some of our early inspection findings, back in the 8 2011 time frame, were really the initial identification 9 of ASR and what that impact was to the sites.
10 Another one would be with the condition 11 monitoring program for the Maintenance Rule. They 12 weren't really evaluating and putting that back into 13 the program for evaluation.
14 I think part of that was growing pains, 15 trying to understand what the issue was, and that led 16 to additional NRC questions and, inevita bly, a public 17 meeting and issuance of the CAL, to fully understand 18 the impacts.
19 Some of those impacts were completing 20 operability determinations on all the affected 21 structures.
22 MR. SCHULTZ: Yes, that's to be appreciated.
23 I thank you.
24 MR. FLOYD: Yes. Just a quick note on the 25 214 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 large-scale testing program implementation, Bryce will 1 provide more details on that later and I'll have key 2 observations during that portion.
3 In 2014, NRC Resident Inspectors 4 identified several instances of large discrete cracks 5 in the Seabrook residual heat removal vaults.
6 The NRC issued a finding of very low safety 7 significance and inspection report dated August 5, 8 2014, because NextEra did not perform an adequate 9 technical evaluation when it was determined that the 10 crack sizes exceeded the quantitative limits specified 11 in plant procedures, per the Structures Monitoring 12 Program. 13 This is actually one indication of 14 Structures Monitoring Program implementation issues 15 and going back from 2011 t o 2014, there was a grouping 16 then, and then, in 2014, a separate grouping, all along 17 the implementation of the program.
18 So, that's what this observation really 19 captures. Also
-- 20 MEMBER MARCH
-LEUBA: Nik?
21 MR. FLOYD:
-- this was one early indication 22 of -- oh , sorry. 23 MEMBER MARCH
-LEUBA: Those large cracks on 24 the residual heat removal system, were they ASR
-induced 25 215 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 or were they other type of stress?
1 MR. FLOYD: Well, that's actually what kind 2 of led to some of the delayed identification.
This 3 cracking went along the interior of the vaults and it 4 was in areas that ASR had not been confirmed.
5 And it didn't make sense why that crack 6 was there. Maybe the thoughts were, was it a cold 7 joint? Was it settlement? And it was the lack of 8 evaluation by NextEra staff that led to it not being 9 evaluated and later being confirmed to be the
-- 10 MEMBER MARCH
-LEUBA: And what was the 11 evaluation at the end? Was it ASR or not?
13 MEMBER MARCH
-LEUBA: It was ASR?
14 MR. FLOYD: Yes.
15 MEMBER MARCH
-LEUBA: So, that's the 16 limiting, not the famous tunnel, but this one?
17 MR. FLOYD: Yes, this is a separate 18 structure that just kind of slipped under the radar.
19 MEMBER MARCH
-LEUBA: Well, if you look at 20 the list that we saw at the end of the presentation, 21 is the limiting one, is the one that has a threshold 22 of 1.2. 23 MR. FLOYD: The RHR bolts?
24 MEMBER MARCH
-LEUBA: Yes. That's the 25 216 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 limiting place.
1 MR. FLOYD: Next slide, please. Later in 2 2015, during a routine plant tour, NRC Resident 3 Inspectors observed degraded fire seals and changes 4 in seismic gaps that appeared to be caused by 5 differential building movement between the adjoining 6 concrete structures.
7 An example of a degraded seismic gap is 8 shown in the picture. The concrete structures are 9 separated by a seismic gap, that's what's shown by the 10 two black vertical lines there. And the change in the 11 gap at the seal can be seen by the associated cracking 12 and separation between the seal and the structure on 13 the right.
14 We have seen instances of b oth increases 15 and decreases in gaps, due to the differences in 16 building deformation.
17 As Angie described earlier, NextEra staff 18 initiated a root cause analysis in response to this 19 observation. This confirmed bulk ASR expansion, 20 resulting in building deform ation. 21 This building deformation impacted some 22 systems and components attached to the adjoining 23 structures, as evidenced by deformed flexible conduit 24 couplings, reduced seismic isolation gaps, and concrete 25 217 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 spalling. Next slide.
1 An example of equipment impacted by 2 deformation is shown in these two pictures. On the 3 left, you can see deformed flexible conduit couplings.
4 On the right, you can see deformed instrument air 5 piping. 6 Building deformation and its impact on 7 equipment was cons idered a new phenomenon related to 8 the effects of ASR. NextEra subsequently developed 9 an additional plant
-specific Aging Management Program 10 to manage this effect, which you heard earlier.
11 The NRC staff continued to perform 12 inspections and audits at the pl ant and issued requests 13 for additional information as needed, to determine 14 whether building deformation would be adequately 15 managed during the period of extended operation.
16 Our inspections have verified that the 17 equipment impacted by building deformation h as been 18 documented and evaluated by NextEra.
19 We've also reviewed the criteria 20 established for acceptability, as detailed in the 21 Building Deformation Monitoring Program, to ensure that 22 the equipment remains functional. Next slide.
23 Overall, Regional inspections have 24 determined that the Seabrook structures remain capable 25 218 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 of performing their safety function. The NRC has 1 observed significant enhancements to the Structures 2 Monitoring Program since the original identification 3 of ASR at Se abrook. 4 Independent walkdowns by the NRC 5 inspectors have not identified any new undocumented 6 structural deficiencies over the past two years.
7 Based on inspections conducted to
-date, 8 NRC inspectors conclude that the licensee is adequately 9 implementing the Structures Monitoring Program and it 10 is appropriately identifying, evaluating, and 11 correcting issues.
12 I will now turn the presentation over to 13 Bryce Lehman to discuss the staff's review of the 14 large-scale testing program, absent any additional 15 questions.
16 MR. LEHMAN: All right, thanks, Nik. I'm 17 going to cover the staff's review of the large
-scale 18 testing program and conclusions from the testing 19 program. 20 Obviously, a lot of this, we covered this 21 morning, so if I think we've already ad dressed it, I'm 22 going to jump over it. If I'm going too fast, just 23 let me know, stop me and ask questions. All right.
24 Next slide, please.
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-3701 (202) 234-4433 And in fact, this one, I think we can skip 1 completely, because it kind of just is an overview of 2 the program and how it was developed, and I think we 3 went over that in detail this morning. So, I'll skip 4 right to the staff's review. All right.
5 The staff reviewed the large
-scale testing 6 program, with a focus on the representativeness of the 7 program and the applicabilit y of the program's 8 conclusions to Seabrook structures.
9 The size of the specimens, the 10 configuration of the reinforcement in the materials 11 used in the specimens, were all much more similar to 12 Seabrook structures than existing literature data.
13 The reinforcement in the specimens is 14 similar to Seabrook structures and provides a realistic 15 structural context which accounts for the confinement 16 provided by the reinforcement and the interaction 17 between concrete and reinforcement.
18 The concrete mix design was based on the 19 original Seabrook design specifications. And when 20 practical, materials were obtained from similar sources 21 as the original construction.
22 Furthermore, the test methods used during 23 the testing program were the same as those metho ds used 24 to establish the empirical design equations in the 25 220 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Seabrook codes of record.
1 Based on these features of the large
-scale 2 testing program, especially the structural context that 3 is provided by using large
-scale specimens with 4 realistic reinforcement, the staff found that the 5 large-scale testing program is representative of 6 Seabrook structures. Next slide, please.
7 In order to use the through
-wall expansion 8 to monitor ASR at Seabrook, it was necessary for NextEra 9 to determine the through
-wall expansion of Seabrook 10 structures that had already occurred prior to 11 instrument installation.
12 NextEra reviewed the large
-scale testing 13 program data and literature data for multiple 14 properties and determined that reduction in modulus 15 of elasticity was the best materi al parameter to 16 determine ASR expansion to
-date. 17 Using data from the testing program, 18 NextEra developed a correlation between normalized 19 modulus and through
-thickness expansion. The staff 20 reviewed the data and noted that the correlation aligns 21 well with the testing data and the available literature 22 data. 23 In addition, the staff noted that a 24 reduction factor was included in the correlation to 25 221 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 account for uncertainty and to provide a conservative 1 expansion value.
2 The staff found this a pproach to estimating 3 through-wall expansion reasonable. However, since 4 this approach has not be corroborated on Seabrook 5 structures, the staff determined that a license 6 condition was necessary to require future confirmatory 7 actions related to the correla tion. 8 MR. SCHULTZ: Bryce, this looks
-- these 9 future confirmatory actions, they seem like 10 substantial, substantial evaluations that are going 11 to occur for 2025 and then, ten years subsequent. Is 12 that -- am I getting the right impression?
13 MR. LEHMAN: Yes, I believe that's correct.
14 I mean -- 15 MR. SCHULTZ: In other words
-- 16 MR. LEHMAN:
-- NextEra kind of went over 17 it this morning, but it's to
-- 18 MR. SCHULTZ: Yes.
19 MR. LEHMAN:
-- verify that the behavior 20 is similar to the University of Texas.
21 MR. SCHULTZ: And t hat could, in fact, 22 require an additional research program, as well as site 23 characterization and evaluations?
24 MR. LEHMAN: Well, I think
-- 25 222 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. SCHULTZ: What
-- I'm trying to get a 1 picture of what you are expecting out of that license 2 condition.
3 MR. LEHMAN: Sure. There's, I mean, 4 there's a lot done in the condition, but it's 5 confirmatory in nature.
6 So, the expectation, based on the 7 representativeness of the testing, is that it will match 8 the behavior. But this is just to confi rm, when they 9 have more data from the onsite structures, the behavior 10 is the same and that the correlation is matching with 11 what's happening at Seabrook.
12 So, the expectation is that it will, but 13 this is corroboration with onsite
-- 14 MR. SCHULTZ: Okay. Is t he condition
-- 15 all I see in the condition is a statement that this 16 is going to be done.
17 But is there enough documentation about 18 the expectation so that six years from now, the NRC 19 and NextEra can determine what needs to be done? They 20 may not be the same people as are here in this room 21 today. 22 MR. LEHMAN: Yes, that's a great point.
23 And the -- you're right, the license condition is fairly 24 high level and just says, this will be done.
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-3701 (202) 234-4433 But it has reference to documents that 1 they've submitted on the docket that were reviewed, 2 which had very specific explanations of how it will 3 be done. So
-- 4 MR. SCHULTZ: Okay.
5 MR. LEHMAN:
-- yes, that detail is there.
6 MEMBER BALLINGER: And it's my 7 understanding that there's AMPs that are in place for 8 this, that are independent of any of this, that will 9 ensure that they'll
-- if they adhere to the AMPs, 10 they'll keep track of it.
11 MR. LEHMAN: Yes. Angie will talk about 12 the management programs a little bit later. But, I 13 mean, this program is in place now an d it will go into 14 license renewal as the Aging Management Program and 15 we'll be tracking all of this stuff.
16 This was just to capture that confirmation 17 piece, to make sure that the behavior aspect is the 18 same from the test program to Seabrook. But, yes
-- 19 C HAIRMAN SKILLMAN: That was
-- 20 MR. LEHMAN:
-- the AMPs are in place as 21 well. 22 CHAIRMAN SKILLMAN: That was the concluding 23 slide from the last presentation. So, I feel 24 comfortable that
-- 25 224 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. SCHULTZ: Thank you.
1 CHAIRMAN SKILLMAN:
-- t he actions going 2 forward are clearly codified for whatever that next 3 generation may be, that will have the accountability 4 to execute this.
5 MR. SCHULTZ: Sounds good, thank you.
6 MS. BUFORD: And I was just going to add 7 that the expectation from carrying out t he license 8 condition is that the NRC, in its continued oversight 9 of Seabrook, if the results are different than expected, 10 then there would be
-- we would expect NRC engagement 11 and Regional oversight activities, how they saw fit, 12 to address a deviation from what they thought to that 13 corroboration piece. So, that's where we would address 14 it. 15 MR. LEHMAN: All right, if we can go to the 16 next slide, that talks about the license condition as 17 well, too.
18 So, the NRC staff is requiring a license 19 condition to confirm that future expansion behavior 20 of ASR-affected Seabrook structures aligns with the 21 large-scale testing program specimens.
22 The first portion of the license condition 23 requires an assessment of overall Seabrook expansion 24 behavior, to ensure that it is similar to the behavior 25 225 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 seen during the testing program, while the second 1 portion of the license condition requires the use of 2 potential future Seabrook expansion data to confirm 3 that the modulus expansion correlation can accurately 4 predi ct expansion. Next slide, please, George.
5 In addition to the NRR staff review, the 6 Division of Engineering and the NRC Office of Nuclear 7 Regulatory Research provided an independent peer review 8 of the test program development and conclusions and 9 the results of their independent review supported the 10 conclusions reached by the NRR reviewers.
11 So, staff conclusion on the review of the 12 LSTP. Based on its review of the testing program and 13 the representativeness of the program, the staff finds 14 that it is reasonab le to apply the results of the testing 15 program to Seabrook structures and to use the original 16 design equations, as long as Seabrook expansion 17 behavior remains similar to the specimens and expansion 18 remains below the tested limits.
19 Unless there is further q uestions, I'll 20 now turn the presentation back to Nik to discuss the 21 Regional oversight of the large
-scale testing program.
22 MR. FLOYD: Thanks, Bryce. The NRC 23 completed a total of six weeks of inspection at the 24 Ferguson Structural Engineering Laboratory at the 25 226 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 University of Texas. This also included one week of 1 a joint inspection audit with the licensing reviewers.
2 As Bryce stated before, the testing was 3 initiated to help resolve the open operability 4 determinations related to ASR at Seabrook. 5 As part of the CAL inspections, that's 6 confirmatory action letter inspections, in 2012 and 7 2013, the NRC verified that the overall testing program 8 approach was sufficient developed and described to 9 support an understanding of the testing plans an d 10 objectives.
11 Our inspections and observations of the 12 testing program allowed for insights into the Seabrook 13 Structures Monitoring Program, the operability 14 determinations, and enhancements to existing Aging 15 Management Programs.
16 The inspectors communicated these results 17 during periodic Seabrook ASR Issue Technical Team 18 meetings and it was this feedback from the inspectors 19 to Headquarters staff, that assisted in their technical 20 review efforts. Next slide, please.
21 One of the significan t observations 22 identified during the testing program, and also seen 23 during our inspections, was the extent of through
-wall 24 expansion examples versus the in
-plane expansion.
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-3701 (202) 234-4433 As a result, NextEra updated its testing 1 program to evaluate the best instrument fo r measuring 2 through-wall expansion, as you heard earlier.
3 The inspectors discussed this testing plan 4 and reviewed the results of the instrument selection 5 study with NextEra staff to verify the reliability of 6 the instrument.
7 NextEra then enhanced their Stru ctures 8 Monitoring Program to include monitoring of 9 through-wall expansion.
10 The inspectors observed the installation 11 of the instruments in the Seabrook walls and during 12 ongoing periodic onsite inspections, we reviewed this 13 inspection data, we also looked fo r trends and we 14 verified the expansion is within the bounds of the 15 testing program. Next slide.
16 Overall, the inspectors observed proper 17 procedural adherence, good test coordination, and 18 proper communications and safety practices exhibited 19 by the testing s taff, the supervisory personnel, and 20 the quality assurance overseers.
21 The inspectors verified proper testing 22 preparations and quality control oversight during each 23 visit to the Structural Lab. And this was really to 24 ensure that suc h testing met appropriate quality 25 228 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 assurance standards.
1 I will now turn the presentation back to 2 Bryce to discuss the staff's review of the proposed 3 Methodology Document.
4 MR. LEHMAN: All right, thanks, Nik. I'm 5 going to discuss the methodology now. A lot of the 6 details on methodology, obviously, have already been 7 covered, so I'm going to try to focus on the staff's 8 review and the associated findings. Next slide. Go 9 back just one.
10 Just a high level of what was in there, 11 as discussed previously, they submitted an LAR to 12 account for the ASR. And the license amendment request 13 proposed a unique three
-stage analysis methodology to 14 address the ASR load and associated building 15 deformations.
16 The proposed methodology includes five 17 supplements to the Seabrook desig n code of record and 18 a detailed description of how to implement the 19 methodology is captured in the Methodology Document.
20 Which I think gets to some of the stuff 21 we were just discussing, the detail of how to do it 22 as they move forward.
23 MEMBER MARCH
-LEUBA: Sorry to ask, 24 procedurally, is this an attachment to the LAR? This 25 229 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Methodology Document?
1 I'm thinking, are you issuing and SER to 2 approve it? Or are you, by approving the LAR, you are 3 implicitly improving the methodology? How are we 4 handling the approval?
5 MR. LEHMAN: Well, it was submitted as 6 support of the LAR and it's referenced in, and we'll 7 get to it a little bit later, but it's referenced in 8 the updated FSAR, with the revision number on there.
9 MEMBER MARCH-LEUBA: Well, if you guys are 10 happy, I'm happy. It's not an issue.
11 MR. LEHMAN: Okay. So, the staff review 12 of the methodology was supported by Brookhaven National 13 Laboratory and included two site audits to review the 14 implementation of the methodology , as well as multiple 15 rounds of request for additional information.
16 The review of the methodology focused on 17 the five areas shown on the slide, and I'll discuss 18 each of these in turn. All right. Next slide, please.
19 The first step in the evaluation 20 methodology is determining the ASR load. Depending 21 on the stage of the analysis, the ASR load is either 22 estimated using concrete strain based on in
-plane 23 expansion or a finite element model is developed for 24 the structure.
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-3701 (202) 234-4433 In situ loads a re applied to the model and 1 the ASR loads and concrete backfill loads due to ASR 2 are adjusted until the model deformations match those 3 measured in the field.
4 The staff reviewed the process for 5 developing the ASR load and finds it reasonable. The 6 Methodology Document clearly defines how the ASR load 7 and concrete backfill load can be adjusted within the 8 model and provides guidance on how it is determined 9 that the model aligns with the field measurements.
10 In addition, the staff audited multiple 11 calculations in each analysis stage and verified that 12 the licensee was estimating the load consistently and 13 in accordance with the guidance in the Methodology 14 Document. 15 MEMBER KIRCHNER: Let me ask here, did you 16 ask the applicant team about qualification of the finite 17 el ement code for this application?
18 Did you look at that at all in
-- I know 19 it's a widely available code, but for this application, 20 did you look at how they actually modeled the 21 structures, the aggregate and the reinforcement, et 22 cetera, in the concrete, in the finite element code 23 in their methodology?
24 MR. LEHMAN: Yes, we did look at that.
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-3701 (202) 234-4433 George, can you expand on that at all?
1 MR. THOMAS: Yes. During the audit, the 2 staff did look at sample calculations to verify 3 implementation of the methodology, including the 4 application of the computer code.
5 MEMBER KIRCHNER: Well, I don't doubt that 6 the applicant knows how to use a finite element code, 7 my question is perhaps a little more nuanced.
8 Is the actual modeling of the structure 9 and the impact of ASR within the finite element code?
10 I mean, is the nodalization sufficient to capture that?
11 I'm not -- I don't find application of a 12 code like that to a large structure showing reasonable 13 agreement as a means for qualifying the code for the 14 task at hand. 15 Usually you would take elements of the 16 large-scale test program, where they actually bent
-- 17 they put loads on beams and check and make sure that 18 the finite element code could reproduce the results 19 of those test. Was anything like that done or chec ked? 20 MR. THOMAS: The way the load was applied 21 was the in
-plane strain was applied as a thermal strain 22 within the ANSYS computer model.
23 MEMBER KIRCHNER: Well, it seems to me it's 24 a rather straightforward application of the
-- it's 25 232 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 AN SYS, isn't it?
-- of the code here to model some of 1 the tests that were conducted in Texas to just make 2 sure that the code can reproduce the measured 3 deformation and stresses that they saw on the test, 4 with these large elements. It's good benchmark 5 materi al. 6 I'm hearing that wasn't done, is what I'm 7 -- I would think someone in Research would suggest that.
8 We typically do that with other codes, when 9 we apply them to systems analysis, do separate effects 10 tests, at least, to make sure that we understand how 11 nodalization and correlation assumptions impact the 12 results. 13 MR. THOMAS: Yes. Let
-- 14 MEMBER KIRCHNER: I guess that's not a 15 question now, it's a comment.
16 MR. THOMAS: Yes. Well, the way the code 17 was used here was in a simple linear elastic analysis, 18 which is a standard analysis. They didn't go further 19 into the nonlinear aspects.
20 MEMBER KIRCHNER: I didn't ask whether you 21 went beyond cracking, but up until that threshold, it 22 would be a useful way to benchmark the application of 23 the code to these structures.
24 MR. LEHMAN: Yes, I think we have a member 25 233 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 from Research who
-- 1 MR. PIRES: Yes, good afternoon. My name 2 is Jose Pires, I'm from the Office of Research. My 3 understanding is that these analyses are not limit state 4 analyses. 5 These a re linear analyses, design
-basis 6 calculations. So, this code has been qualified for 7 this purpose. It is used frequently to analyze 8 reinforced concrete structures for design 9 calculations.
10 The tests, the testing program went way 11 past the design limits. Th ey are ultimate capacity 12 tests to see if the stress equations in the ACI are 13 applicable. So, they went way past the regime in which 14 the code was used for. The code
-- 15 MEMBER KIRCHNER: I understand that.
16 MR. PIRES:
-- the calculations of the code 17 didn't g o to that level of deformation and response, 18 are way below that. So, that's
-- and the code has 19 been qualified for that purpose, because it's used 20 extensively for design analysis for applications.
21 MEMBER KIRCHNER: I understand all that. 22 What I'm asking you is, you're studying the effect of 23 ASR on the performance of these structures.
24 And it would seem to me, are you saying 25 234 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 that there was no
-- I'm interested in how you put in 1 the material properties to the code and how you 2 nodalized that model to take into account the variation 3 in ASR, because you had samples of various levels of 4 ASR degradation.
5 MEMBER BALLINGER: In particular, the 6 modulus? That's really what would be affected.
7 MR. PIRES: Right.
8 MEMBER RICCARDELLA: Well, I mean, th ere 9 were some modeling assumptions that were made. You 10 used shell elements for the shell, you used membrane 11 elements for the rebar.
12 These are modeling assumptions that could 13 have been
-- that could be tested in the
-- against, 14 say, one of the beam test pr ograms, to show that you're 15 calculating the proper stresses in the rebar, up to 16 cracking, or things of that sort. I think that's what 17 Walt is getting to.
18 DR. BAYRAK: Certainly, this is
-- once 19 again, this is Ozzie Bayrak. Such val idations are 20 always useful, but just to go back to the point that 21 the analyses conducted are linear elastic, using ANSYS.
22 And if you recall one of the slides I 23 showed, on our rebar anchorage test programs, where 24 we're looking into actually a family of curv es, we 25 235 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 looked into the first part, control specimen versus 1 ASR-affected, where the stiffness does not change 2 appreciably.
3 So, that is the range in which you would 4 be doing this validation. And ANSYS, I've used it a 5 number of times, not in the recent past, but in terms 6 of analyzing a typical reinforced concrete beam 7 behavior, it does that just fine.
8 I would be surprised if such an analysis 9 showed that, particularly within that range, the 10 behavior cannot be captured.
11 Now, later on in the game, when you have 12 flexural cracking, yielding, and so on and so forth, 13 such nonlinear actions, can you pick that up with ANSYS?
14 My answer to that would be, I have no idea. But for 15 the linear elastic portion, I'm fairly confident.
16 MEMBER KIRCHNER: Okay.
17 DR. BAYRAK: I think that's -- 18 MEMBER KIRCHNER: All right, thank you.
19 DR. BAYRAK:
-- what you were trying to 20 indicate. 21 MR. PIRES: The intent of the testing 22 program, the methodology and so forth, was that you 23 could do that. That you could map the probl em into 24 the design analysis situation. So, that was the 25 236 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 purpose. 1 CHAIRMAN SKILLMAN: Let's keep on going.
2 MR. LEHMAN: All right. I think we're on 3 the next slide, George. And that's all, so I think 4 we understood the comment. Are there any other 5 questions on that? All right, moving on.
6 MEMBER RICCARDELLA: Did the staff do any 7 independent calculations?
8 MR. LEHMAN: No, we did not. But I think 9 we understood the comment and we'll look at it more.
10 The next topic is the development of ASR 11 load factors. So, ne xt slide, please. There, 12 perfect. 13 To incorporate the ASR load into the 14 existing load combinations, it was necessary to develop 15 load factors for the ASR load. The factors for ASR 16 were developed based on the reliability index approach 17 used to develop proba bilistic-based load factors in 18 ACI 318 and ASE 7.
19 The staff finds this approach reasonable, 20 because it follows the same method used in industry 21 consensus standards and the developed factors maintain 22 the original reliability of the d esign-basis load 23 combination.
24 The resulting ASR load factors will be 25 237 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 incorporated into the updated Final Safety Analysis 1 Report. Next slide, please.
2 The original license amendment request 3 included multiple analysis methods that appeared to 4 be departures from the codes of record. In response 5 to staff requests for additional information and 6 discussions during site audits, NextEra identified five 7 supplements to the existing codes of record.
8 Supplement 1 was identified as the 9 incorporation of ASR loads into the existing FSAR 10 design-basis load combinations. The staff finds this 11 supplement acceptable, because it officially 12 incorporates ASR loads into the design basis.
13 Supplement 2 was identified as the use of 14 the original design code equations to determine the 15 strength of ASR
-affected concrete sections. As 16 discussed previously, the staff finds this supplement 17 acceptable, based on the results of the large
-scale 18 testing program. Next slide, please.
19 Supplement 3 was identified as using the 20 procedures defined in ACI 318
-83, Section 11.7, to 21 calculate shear friction capacity for members subjected 22 to net compression.
23 The staff finds this supplement 24 acceptable, because the guidance is identical to 25 238 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Section 11.7 of ACI 349
-97, which is endorsed b y the 1 staff in Reg Guide 1.142. Next slide, please.
2 The staff reviewed Supplements 4and 5 3 together, because both supplements relate to crack 4 section properties. Supplement 4 deals with flexural 5 crack section properties, while Supplement 5 addresses 6 axial and shear stiffness of structural components.
7 The staff noted that the approach was 8 reasonable for normal concrete, but did not appear to 9 account for the test results, which indicated a relative 10 increase in stiffness with ASR due to the ASR 11 pre-stressing effect. 12 The staff discussed this issue with NextEra 13 during an audit and issued an RAI. In response to the 14 RAI, NextEra revised the referenced equations and the 15 guidance in the Methodology Document to account for 16 the observed increases in stiffness.
17 The Methodology Document clarifies the 18 tensile and shear crack initiations are based on net 19 concrete strength after the ASR pre
-stressing effects 20 are overcome.
21 The staff finds this approach acceptable, 22 because it is consistent with industry standards for 23 developing crack section properties and the revised 24 guidance in the Methodology Document ensures the ASR 25 239 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 pre-stressing effects are taken into account in the 1 analysis. 2 The next main topic of review is the 3 threshold factor and threshold limits. These are 4 structure-specific outputs of the methodology that 5 quantify the remaining margin in each structure.
6 The staff finds the use of the threshold 7 factors and threshold limits acceptable, because the 8 calculations used to develop the values follow the 9 design code of record with acceptable supplements as 10 just discussed.
11 The threshold factor allows for future ASR 12 expansion and quantifies the remaining margin in each 13 structure.
14 If an acceptable factor cannot be developed 15 or if a threshold limit is reached, a more detailed 16 analysis stage may be entered or a structural 17 modification may be developed to reestablish the 18 margin. Next slide, please.
19 The last major topic reviewed by the staff 20 as part of the methodology relates to reinforcement 21 stresses and strains.
22 The Seabrook design code of record requires 23 that stress and strains in structures remain within 24 elastic limits under normal operation or service load 25 240 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 conditions.
1 However, unlike other service loads, ASR 2 expansion is a self-straining load whose progression 3 has a potential for straining reinforcement beyond 4 yield under service conditions.
5 To address this, NextEra identified 6 additional actions that will be taken if the in
-plane 7 ASR strain exceeds two millimeters per meter over a 8 large region, which is the approximate level at which 9 rebar could yield, based on minimum specified yield 10 strength. 11 If this limit is exceeded, the Methodology 12 Document recommends further evaluation of the area, 13 which could result in a retrofit or re pair to mitigate 14 possible reinforcement yield or slippage, or could 15 result in further analysis to qualify the structure.
16 MEMBER MARCH
-LEUBA: I know it's late, but 17 remind me again
-- maybe I should ask the boss. On 18 the CRs, we put limitations and condition
- s. 19 On LAR approvals, we don't add limitations, 20 right? So, we either approve what the licensee 21 proposes as these limits or we reject it, is that the 22 case? 23 MR. DONOGHUE: In this case, we're approving 24 with license conditions. So, the y have to satisfy 25 241 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 those license conditions as part of their license now.
1 MEMBER MARCH
-LEUBA: So, we can add
-- 2 MR. DONOGHUE: Once it's approved.
3 MEMBER MARCH
-LEUBA: -- a license condition 4 on the LAR? You can add a condition to the LAR?
5 MR. DONOGHUE: Yes.
Now -- 6 MEMBER MARCH
-LEUBA: Okay.
7 MR. DONOGHUE:
-- there's some particulars 8 about that and we had to work with the licensee to make 9 sure that it's something that's confirmatory.
10 It's not going to be new analyses or 11 information that are given to us to revie w, it's 12 something that can be confirmed by inspection, 13 basically.
14 MEMBER MARCH
-LEUBA: So, there is a process 15 to get that? I was thinking
-- 16 MR. DONOGHUE: Yes.
17 MEMBER MARCH
-LEUBA: -- because we run into 18 that problem with the design certifications.
19 MR. DONOGHUE: Right. So, this gets
-- 20 MEMBER MARCH
-LEUBA: And I'm
-- 21 MR. DONOGHUE: I'm sorry. This gets back 22 to an earlier question about, if it's not spelled out 23 in the condition, where is it?
24 And that's where we're depending on their 25 242 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 ag ing programs and the documentation they have to follow 1 and our oversight, I think Angie mentioned this, our 2 oversight is going to confirm that they live up to their 3 programs. And we do this in all areas throughout the 4 plant, besides just monitoring ASR.
5 M EMBER MARCH
-LEUBA: In opening my mouth, 6 I think I answered my question myself
-- 7 MR. DONOGHUE: Okay.
8 MEMBER MARCH
-LEUBA: -- you need an SER if 9 you're modifying Tech Specs.
10 MR. DONOGHUE: Right.
11 MEMBER MARCH
-LEUBA: But because this 12 doesn't modify Tech Specs, what they have done is a 13 regulatory commitment.
14 MR. DONOGHUE: Well, no, it's a license 15 condition and they are modifying their license, because 16 now, this program is going to be part of their
-- it's 17 going to be put in their UFSAR. And they
-- 18 MEMBER MARCH
-LEUBA: And there is
-- 19 MR. DONOGHUE:
-- we needed that
-- so, the 20 reason these are coupled to the license renewal is they 21 needed to get this into their current licensing basis 22 to get the license renewal submitted.
23 MEMB ER MARCH-LEUBA: And there is no doubt 24 in my mind that they will follow the proper methodology.
25 243 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MR. OESTERLE: Yes, so, just let me add 1 something. The
-- earlier in the discussion today
-- 2 oh, sorry, Eric Oesterle, DMLR.
3 Earlier in the discussion today, the re was 4 mention that the staff had a difference of opinion with 5 NextEra in that, because this was a new method of 6 evaluation, it needed to be incorporated into the UFSAR 7 and the process to do that is via a license amendment.
8 So, if you look at the criteria in 50.59, 9 there's a question in there about a new method of 10 evaluation. And so, that tripped a criteria, which 11 requires a license amendment to include it in the FSAR.
12 MR. LEHMAN: But just to clarify, this limit 13 is not part of the license condition. This is not 14 captured in the license condition, this is captured 15 clearly in the Methodology Document, which is 16 referenced in their FSAR update. So, we would still 17 have oversight of it, but it's not part of the license 18 condition.
19 So, the staff finds this approach 20 acceptable, because a reasonable limit for in
-plane 21 ASR strain has been identified and if the limit is 22 exceeded, further evaluation will be performed, 23 including the evaluation of potential rebar slip or 24 yield under service conditi ons. Next slide, please.
25 244 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 This is sort of the overall summary. The 1 staff reviewed the methodology and based on its review, 2 the staff finds that NextEra's evaluation method is 3 a reasonable approach for analyzing structures with 4 ASR, because the approach is consistent with Seabrook's 5 code of record design philosophy.
6 NextEra provided acceptable justification 7 for the continued applicability of the code, along with 8 the five proposed supplements to the code.
9 NextEra's approach for estimating the load 10 due to ASR is reasonable and based on field data, and 11 the load is incorporated into the existing load 12 combinations with reasonable load factors.
13 The methodology quantifies the future ASR 14 expansion that can be accommodated by a structure and 15 i dentifies quantitative acceptance criteria for 16 threshold parameters for each structure.
17 Additionally, limits are in place to ensure 18 structures are evaluated for potential rebar yield 19 under service loads and monitoring programs are in place 20 to ensure ASR ex pansion remains within the identified 21 test program limits and structure
-specific threshold 22 limits. 23 Angie will discuss the monitoring programs 24 in more detail in the upcoming slides.
25 245 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Finally, confirmatory actions in the 1 license condition provide assurance th at the 2 large-scale testing program results will continue to 3 be applicable to Seabrook structures. Next slide, 4 please. 5 The staff also finds that NextEra's 6 evaluation methodology is adequately captured in the 7 Methodology Document and the proposed UFSAR upda te. 8 The staff audited multiple calculations 9 in each analysis stage and determined the Methodology 10 Document is robust and detailed enough to be repeatable 11 for any structure or analysis stage.
12 The Methodology Document will provide 13 app ropriate monitoring parameters and associated 14 acceptance criteria for each analyzed structure.
15 The UFSAR update captures the five code 16 supplements and references the Methodology Document.
17 The UFSAR also includes the ASR load and the updated 18 load combinations and identifies the expansion limits.
19 Based on its review, the staff finds that 20 the proposed methodology is adequately described in 21 the proposed UFSAR update and provides reasonable 22 assurance that ASR
-affected structures will continue 23 to meet the design codes as supplemented.
24 That concludes my presentation on the 25 246 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 evaluation methodology and I will turn the presentation 1 over to Angie to discuss ASR monitoring and 2 plant-specific AMPs.
3 MS. BUFORD: Okay. Thanks, Bryce. So, the 4 applicant has proposed and is implementing monitoring 5 programs that rely on the robust methodology that the 6 licensee is crediting in their license amendment 7 request and their plan is to monitor ASR
-related 8 behaviors under two plant
-specific programs.
9 The staff reviewed the programs against 10 the plant-specific review guidelines, per the 11 ten-element review process outlined in the Standard 12 Review Plan for License Renewal.
13 We thought that appropriate, considering 14 that the programs that are being implemented today a re 15 the programs that are planned for the period of extended 16 operation.
17 This next slide has been covered, it's just 18 a high level overview of the ASR monitoring plan. So, 19 for time, we'll just move to the next slide.
20 MEMBER KIRCHNER: Sorry to slow you down.
21 MS. BUFORD: Sure, no problem.
22 MEMBER KIRCHNER: I have a question about 23 methodology for the building deformation. Is there 24 any plan to estimate gross movement of individual 25 247 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 buildings because of pressure from the backfill 1 expansion and what's the consequenc e of that?
2 Is there any limits to
-- hypothetically, 3 just say there's a gap there for seismic purposes and 4 it's closing because of expansion and pressure. Is 5 there any program in place that defines an acceptable 6 methodology for estimating that and predict ing it going 7 forward? 8 Or is it going to be a reactive monitor 9 what the gap is and, at some point, if it closes and 10 creates a seismic or other induced load, then you 11 mitigate that or calculate your way out of it or 12 whatever? 13 I mean, is that the response to this issue 14 of building deformation that's because the structures 15 float and are being pushed, if you will, and stressed 16 by the backfill expanding?
17 MS. BUFORD: Yes. So, our review process 18 for their
-- the licensee actually has a spec ific 19 program called the Building Deformation Monitoring 20 Program that
-- 21 MEMBER KIRCHNER: Right, I saw that coming 22 up. 23 MS. BUFORD: Yes, so that is coming
-- 24 MEMBER KIRCHNER: Right.
25 248 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MS. BUFORD:
-- up, but that's what you're 1 referring to. And so, what that program does is that 2 it looks at all of the different
-- for each structure, 3 it looks at the different parameters that are unique 4 to that structure that are related to both ASR and any 5 movement, large cracks, and any ASR
-related or building 6 deformation agi ng effects.
7 And our guidance says that, when we review 8 this, we need to see that indications are both trended 9 and also there's a forward look in the review to say 10 that the licensee needs to show that, based on prior 11 trending, that they will not reach their threshold 12 limits for any of the monitored parameters before the 13 next inspection time.
14 And we've heard today that there's 15 actually, even though it's not part of the guidance 16 for license renewal, NextEra actually has a limit that's 17 what they were calling their administrative limit, 18 that's actually even before they would get
-- so, that's 19 actually the limit they use, which has a conservatism 20 even built into that.
21 That's actually what they're trending to, 22 so the program trends up to the next inspection, based 23 on previous movement. And like we said, it's slow and 24 they have years' worth of data that they can use to 25 249 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 trend. 1 And every structure is different, so there 2 is essentially a Building Deformation Monitoring 3 Program for every structur
- e. Does that
-- 4 MEMBER KIRCHNER: Okay.
5 MS. BUFORD:
-- answer your question?
6 MEMBER KIRCHNER: Kind of, sort of, yes.
7 MR. LEHMAN: I can expand on that.
8 MEMBER KIRCHNER: It's a little different, 9 I guess, this problem or issue or
-- than the actual 10 reinforced concrete structures, which they bounded with 11 their large
-scale test program.
12 And now, you're working within a defined 13 envelope or limits to make sure you don't exceed what 14 was tested.
15 I don't expect a test program for bulk 16 deformation or large
-scale movement of buildings, but 17 I was just curious how you project out through the life 18 of the license and the renewal application.
19 MS. BUFORD: So, the test program is not 20 -- it was not directly related to the
-- 21 MEMBER KIRCHNER: No, I -- 22 MS. BUFORD:
-- building deformation, but 23 -- 24 MEMBER KIRCHNER:
-- admit that, that's 25 250 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 quite different.
1 MS. BUFORD: So, actually, the inputs from 2 the test program specific to the actual ASR expansion, 3 that's the ASR monitoring program, which it's actually 4 the other program.
5 MEMBER KIRCHNER: Okay.
6 MS. BUFORD: So, the ASR monitoring program 7 is specifically looking at the in
-plane cracking and 8 the through
-wall cracking and directly comparing to 9 those testing limits.
10 MEMBER KIRCHNER: I understand that 11 complete ly. 12 MS. BUFORD: The Building Deformation 13 Monitoring Program takes
-- weaves conclusions from 14 the testing program into the calculation that governs 15 the extent of aging effects for the
-- so, it basically 16 wove into the calculation.
17 An d it's not
-- the testing program isn't 18 being in any way tied directly
-- 19 MEMBER KIRCHNER: No, I understood all that.
20 No, I'm -- I guess, indirectly, what I'm asking is, 21 is there an effort underway to estimate what bulk 22 deformation would occur through the license renewal 23 application time period?
24 MS. BUFORD: So, no. Our process for the 25 251 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 -- in our programmatic review, we look to understand 1 that there are mechanisms in place to
-- and I think 2 that Michael Collins alluded to this previously in the 3 presentation, where we're not looking for them to 4 estimate out the, either the expansion or the bulk 5 deformation through any time period except to the next 6 inspection. And that the monitoring criteria will 7 identify deficiencies prior to that.
8 But there's no
-- it's o ur understand and 9 it's acceptable to the staff that there is not a 10 projection out to any extended time period, because 11 -- 12 MEMBER KIRCHNER: To the 26
-year or whatever 13 -- 14 MS. BUFORD:
-- it's a condition monitoring 15 program. 16 MEMBER KIRC HNER: -- the time frame is.
17 MS. BUFORD: Yes. So, if at any point
-- 18 MEMBER KIRCHNER: So, it's a more reactive, 19 monitor and react approach, rather than to bound the 20 problem, like you did with the large
-scale test program?
21 MS. BUFORD: We'd call it more cond ition 22 monitoring, because
-- 23 MEMBER KIRCHNER: Okay.
24 MS. BUFORD:
-- you're monitoring 25 252 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 conditions up to a point at which you need to go into 1 your Corrective Action Program and look into 2 operability of structures. And that's based on the 3 work that was done.
4 But the -- programmatically, the NRC looks 5 to make sure that the programs can effectively identify 6 any of the aging effects associated with the structure 7 prior to the next scheduled inspection.
8 MEMBER KIRCHNER: Well, typically, when we 9 have an issue surfa ce like this, I would hope that 10 Research would be involved and they would be thinking 11 through, okay, what's the implication of this?
12 I'll bring up some analogies, I guess, at 13 some risk, like reactor vessel degradation, because 14 of neutron irradiation.
15 What you do is estimate out to the lifetime 16 of the reactor vessel what the fluence is and what the 17 effect is on the structural capacity of the reactor 18 vessel. 19 Here, it's a little bit different, because 20 we're talking about bulk movement , but I would think 21 that one would want to take a stab at estimating how 22 these islands are floating and being moved, to see 23 whether or not you would then, in the lifetime of the 24 plant, have a condition occur where you have, let me 25 253 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 say, building to building contact that's unacceptable 1 because of the loads it would induce, et cetera.
2 So, I'm just curious if any work is underway 3 to look at that aspect of the problem, or are you just 4 going to monitor
-- 5 MS. BUFORD: So, we don't have
-- 6 MEMBER KIRCHNER:
-- and r eact? 7 MS. BUFORD:
-- any work underway to do that, 8 and that's
-- there is a specific reason for that, 9 because those types of analyses are, under the 10 regulations, are time
-limited aging analyses.
11 And those are the analyses that look out 12 to the end of life of the plant and either bound the 13 behavior or propose Aging Management activities.
14 One of the criteria for a time
-limited 15 aging analysis that looks out to the end of plant life 16 is that there is an analysis that's already in the 17 licensing basis that's associated with time, where it 18 was assumed that there would be a 40
-year license and 19 then, licensees, applicants, have to revisit that 20 40-year analysis out to the extended period.
21 In this case, there's not a licensing basis 22 calculation as sociated with
-- 23 MEMBER KIRCHNER: I understand, because
-- 24 MS. BUFORD:
-- the life of the plant
-- 25 254 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 MEMBER KIRCHNER:
-- you discovered this 1 in 2014. 2 MS. BUFORD: Well, right. But in terms of 3 our -- it's acceptable and adequate for this to be a 4 condition mon itoring program, so long as aging effects 5 can be identified
-- 6 MEMBER KIRCHNER: Okay, fair enough.
7 MS. BUFORD:
-- prior to the next 8 inspection.
9 MEMBER KIRCHNER: That's fair enough.
10 Thank you.
11 MR. COLLINS: So, the issue of the backfill 12 concrete, those loads are being applied by SG&H, as 13 far as in their buildings analysis.
14 And we have our threshold limits and those 15 threshold limits drive the inspection criteria, whether 16 it be a seismic gap, whether it be a distances between 17 fire gaps.
So, we're not expecting a massive blowout 18 of a wall, so we are
-- 19 MEMBER KIRCHNER: No, I wasn't
-- 20 MR. COLLINS: No, and I
-- 21 MEMBER KIRCHNER:
-- suggesting that.
22 MR. COLLINS:
-- know you weren't. But I 23 think we got a little dysfunction there with regard s 24 to the backfill concrete. That is being monitored, 25 255 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 that input of that backfill concrete is being input 1 into our analysis of
-- 2 MEMBER KIRCHNER: Okay, fair enough.
3 MR. COLLINS:
-- the structures.
4 MEMBER RICCARDELLA: Could I just make sure 5 my understanding is correct? You've done the 6 structural models of each of the structures, certainly 7 the ones that fall into the Stage Three.
8 And my understanding is that the Building 9 Deformation Monitoring Program is just there to confirm 10 the predictions of those structural models. So, that 11 it has been modeled, by including the factor, I forget, 12 the threshold factor in there, that does take it to 13 the end of life.
14 If you go in there and measure something 15 that says, well, I'm right up t o the threshold, to that 16 threshold factor, you basically have to take an action.
17 MR. COLLINS: That's correct.
18 MEMBER RICCARDELLA: Right?
19 MR. COLLINS: Yes. And I'm Michael 20 Collins, Director of Engineering, Seabrook Station.
21 MEMBER RICCARDELLA: Yes. I mean , that 22 might not be so true for the ones that are maybe a Stage 23 One or a Stage Two, but certainly for anything that 24 was Stage Three, you've got a finite element model 25 256 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 predicting deformations and your monitoring program, 1 as I understand it, is just to confi rm those 2 measurements, right?
3 MR. COLLINS: That's well said.
4 MEMBER RICCARDELLA: Okay, thank you.
5 MR. LEHMAN: And also, for all of the stages, 6 that limit is a limit they have to take action at.
7 But at a Stage One, it might just be, go to a Stage 8 Two, or go to a Stage Three. At a Stage Three, it's 9 a little bit more and the action might be a mod at that 10 point. 11 MEMBER RICCARDELLA: Understood.
12 MR. THOMAS: This is George Thomas. Just 13 to add to that, even if it's a Stage One analysis, i f 14 the field observations indicate that the seismic gap 15 is an important parameter, that would be identified 16 as the threshold parameter and monitored. So, it's 17 all field data driven.
18 CHAIRMAN SKILLMAN: Let's proceed, please.
19 MS. BUFORD: Okay. So, we were g oing to 20 move to the next slide. We were trying to skip that 21 slide and so, we are going to still. So, I'm going 22 to go back, I know we talked a little bit about the 23 building deformation monitoring, but that's coming in 24 a couple slides.
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-3701 (202) 234-4433 The ASR monitoring p rogram, the staff 1 reviewed the ASR monitoring program using the 2 ten-element review guidance that I mentioned in the 3 Standard Review Plan for License Renewal.
4 And we noted that visual inspections are 5 performed. And for any concrete onsite, that's a 6 five-year basis. That's the baseline. And the 7 frequency for the baseline inspections is adequate
-- 8 and actually, I won't call them baseline, but I'll call 9 them routine structures monitoring inspections.
10 That frequency is adequate becaus e, 11 firstly, NextEra has already performed a comprehensive 12 baseline inspection on all concrete at Seabrook. Any 13 area with visual indications of ASR were noted in that 14 baseline inspection. The five
-year inspection is for 15 concrete where ASR has not been pre viously identified.
16 The staff agrees that five years is 17 sufficient to be able to both detect initial signs of 18 ASR, since ASR is a slow progressive phenomenon, and 19 has confidence that it would be unlikely for that area 20 to progress from having no signs of AS R to having ASR 21 damage that could challenge the intended function.
22 The inspection frequencies for all 23 locations that have any indication of ASR are 30 months 24 and move to six months, according to ASR severity.
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-3701 (202) 234-4433 The program uses combined cracking index, 1 which you've heard extensively today, to measure 2 in-plane cracking for areas whose CCI measures less 3 than one millimeter per meter.
4 The staff agrees that CCI is a valid method 5 of measuring ASR micro
-cracking, because it was
-- well, 6 one, it is the standard for
-- it's noted in the Federal 7 Highway Administration literature. And also, just 8 because it was found by the large
-scale testing program 9 to correlate well to concrete strain.
10 And also, the one millimeter per meter 11 threshold for more frequent inspections is very 12 conservative, because it represents a low level of 13 strain. 14 For these low ASR severity levels, the 15 30-month frequency associated is conservative based 16 on the slow rate of ASR progression.
17 This has also been validated with data from 18 Seabrook structures and the staff has confidence that 19 for a low ASR severity, a 30
-month inspection interval 20 will identify degradation and trend to the next 21 inspection prior to a loss of intended function.
22 Through-wall expansion is measured in any 23 structure whose CCI exceeds one millimeter per meter.
24 As I mentioned, the testing program demonstrated that 25 259 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 through-wall expansion exceeded in
-plane expansion for 1 structures with more severe ASR degradation.
2 One millimeter per meter expansion is a 3 low and conservative factor for through
-wall 4 extensometer installation.
5 The through
-wall expansions are measured 6 every six months for every location that uses an 7 extensometer and the expansion limits are based on 8 expansion data from the testing program.
9 Since the large
-scale testing specimens 10 exceeded their structural acceptability, staff has 11 confidence that as long as the Seabrook structures 12 remain within the tested limits, they will be able to 13 perform their intended functions.
Next slide.
14 The staff finds that NextEra's ASR 15 monitoring program is acceptable, because the program 16 begins with visual inspections and progresses to 17 expansion monitoring, as necessary, for increased 18 levels of ASR degradation.
19 The inspection frequencies ar e 20 conservative and are aligned with guidance in ACI 21 349.3R. 22 The starting point of the five
-year 23 frequency aligns with the GALL report recommendations 24 for inspection of concrete in an aggressive 25 260 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 environment, which Seabrook concrete is considered to 1 be, sinc e they are susceptible to ASR.
2 The staff has also performed numerous 3 inspections under the reactor oversight process that 4 look at the expansion and deformation behavior and these 5 inspections have concluded that ASR progress has been 6 very slow.
7 In addition, the ASR monitoring program 8 compares total volumetric expansion against reasonable 9 limits from the testing program and license conditions 10 are in place to assess continued assurance that the 11 testing program is valid and representative of 12 Seabrook. 13 In addition, as reflected in the operating 14 experience program element of the program, the program 15 will monitor and evaluate future industry and 16 plant-specific operating experience and the program 17 will be modified if necessary.
18 Any questions on the ASR AMP? Okay. Next 19 slide. 20 So, the other program to manage ASR is the 21 Building Deformation Monitoring AMP. For this AMP, 22 structures with indications of ASR micro
-cracking and 23 any other manifestations of ASR are analyzed using the 24 pro posed methodology that was discussed earlier.
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-3701 (202) 234-4433 For each structure, analysis defined 1 structure-specific parameters to monitor and has 2 acceptance criteria that is based on an evaluation 3 that's unique to that structure.
4 The program identifies and monitors 5 parameters generated from the Methodology Document and 6 those parameters are quantitative when feasible.
7 Also, the licensee has established a unique 8 program for each structure that references threshold 9 factors that must be met and trended to the next 10 inspection
. 11 For each structure, the inspection 12 interval is either three years, 18 months, or six 13 months, based on the stage of analysis, essentially 14 considering the level of conservatism in the 15 calculation or the potential for building deform ations 16 to become more severe.
17 The staff believes these frequencies to 18 be adequate in its audit and review of a sample of each 19 stage of analysis and notes that for areas with higher 20 potential to reach the threshold, i.e., the Stage Three 21 analyses, a six
-mon th frequency is very conservative 22 considering the ASR progression is very slow.
23 The staff concludes that the 24 implementation of the Building Deformation Monitoring 25 262 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 Program ensures structures continue to meet the code 1 of record, with supplements, if measurem ents remain 2 below the acceptance criteria. Next slide, please.
3 The staff finds the proposed Building 4 Deformation Monitoring AMP acceptable, because the 5 program identifies appropriate monitoring parameters 6 and acceptance criteria based on the Methodology 7 Document, which the staff has found technically 8 adequate. 9 The Methodology Document has identified 10 the method for monitoring each possible parameter.
11 The staff also finds that the program uses 12 conservative inspection intervals, which are frequent 13 enough to ensure significant changes in deformation 14 are identified and remediation can take place prior 15 to a loss of intended function.
16 The monitoring is based on more and more 17 stringent frequencies based on ASR degradation and the 18 staff has confidence, because we noted from trended 19 data that ASR has progressed slowly.
20 In addition, the inspection frequencies 21 associated with this aging mechanism are closely tied 22 with ACI 349.3R guidance for sites that have operating 23 experience with respect to s ignificant degradation 24 mechanisms.
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-3701 (202) 234-4433 Also, the staff noted that the program 1 includes structural, electrical, and mechanical 2 components in the plant that may be impacted by 3 structural deformations.
4 These components will also be monitored 5 for continued deforma tion effects and we verified 6 implementation in the licensee's database during our 7 onsite inspection.
8 Finally, the Building Deformation 9 Monitoring AMP will monitor and evaluate future 10 industry and plant
-specific operating experience and 11 modify the program as necessary.
12 If there are no questions, I will turn the 13 presentation back to Nik so he can discuss the follow
-up 14 license renewal inspection at Seabrook for ASR.
15 MR. FLOYD: Thank you, Angie. Next slide, 16 please. George, next slide.
Oh, thank you.
17 The NRC conducted a second license renewal 18 inspection at Seabrook to determine whether actions 19 taken by NextEra since the previous license renewal 20 inspection conducted in 2011 was adequate to manage 21 aging in concrete structures due to the e ffects of ASR.
22 The inspection was focused solely on ASR, 23 because the 2011 inspection reviewed the other Aging 24 Management Programs.
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-3701 (202) 234-4433 The timing of this inspection was prompted 1 by NextEra's completion of the large
-scale testing 2 program, NextEra's submittal of the license amendment 3 request, updates to the Aging Management Programs for 4 the license renewal application, and the NRC completion 5 of staff licensing audits.
6 The inspection involved one Regional 7 Inspector, who was myself, and one Headquarters 8 Inspector, who was Angie, with expertise in both 9 materials and civil engineering.
10 The team was onsite the week of April 30, 11 2018 and the inspection report was issued August 10, 12 2018. Next slide, please.
13 The team reviewed the Aging Management 14 Programs associated with ASR. These were the 15 Structures Monitoring Program, ASR, Building 16 Deformation, and ASME Section 11, Subsection IWL, for 17 containment concrete inspections.
18 The team performed detailed walkdowns on 19 a sample of three structures affecte d by ASR and 20 verified that the structural deficiencies were being 21 identified, evaluated, and corrected by the applicant.
22 The team did not identify any new deficiencies that 23 were not previously documented.
24 The team also performed an in
-depth review 25 265 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 of the Structures Monitoring Program database. This 1 database captures the results of NextEra's monitoring 2 of structures per the Maintenance Rule and also includes 3 the monitoring results from the ASR monitoring and the 4 Building Deformation Monitoring Programs. N ext slide.
5 NRC Regional Management provided oversight 6 during this inspection. In the photo, you can see the 7 team on the left and the right, provided their 8 observations and assessments on the Structures 9 Monitoring Program during a w alkdown in the Fuel Storage 10 Building. 11 The binder, which you can see in the photo, 12 contained a list of NextEra's documented structural 13 deficiencies, which the inspectors used during their 14 walkdowns to independently verify that all deficiencies 15 were being ap propriately identified. Next slide, 16 please. 17 From the walkdown and review of the 18 Structures Monitoring Program database, the team 19 determined that NextEra was implementing the 20 established monitoring programs and was appropriately 21 identifying and correcting issues. 22 The team noted that all in
-scope buildings 23 were being monitored in the Structures Monitoring 24 Program for ASR.
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-3701 (202) 234-4433 As part of the new Aging Management 1 Programs, we reviewed ASR
-specific monitoring 2 parameters.
3 Those would include combined crack 4 indexing grids, pin
-to-pin expansions, extensometers, 5 as well as building deformation monitoring parameters, 6 which would include seismic gap and specified cracking.
7 We determined that these parameters were 8 adequately captured in the program and were being 9 monitored at the program
-specified frequencies.
10 NRC inspections of ASR
-related issues 11 completed to
-date, which would include the semiannual 12 focus inspections, as well as this follow
-up license 13 renewal inspection, support the conclusion that there 14 is reasonable assurance that the effects of aging due 15 to ASR in Seabrook structures, systems, and components 16 will be managed through implementation of the programs 17 during the period of extended operation.
18 Also, just a quick note, review of this 19 database, as well as this inspection, did provide us 20 confidence in NextEra staff's ability to implement the 21 program, given its extensive processes for monitoring.
22 As far as just, and this is my personal 23 opinion, as far as benchmarking and Structures 24 Monitoring programs go, this really is probably the 25 267 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 most comprehensive Structures Monitoring Program that 1 I've observed. So, I'll just offer that observation.
2 Are there any questions on the scope of 3 the inspection or observations? Thanks very much.
4 I'll turn it back over to Angie.
5 MS. BUFORD: Home stretch. I'm going to 6 now finish the staff's presentation with our 7 conclusions. Next slide, okay.
8 The staff found that there are acceptable 9 plant-specific AMPs provided for both ASR monitori ng 10 and building deformation.
11 We found that the existing structures 12 monitoring and ASME Section 11, Subsection IWL AMPs, 13 and structural Aging Management review items have been 14 updated to reflect ASR. And that also includes 15 components that are affected by b uilding deformation.
16 The license renewal safety evaluation 17 report conclusions rely on the large
-scale testing 18 program and the license amendment request safety 19 evaluation findings.
20 The SER focuses on monitoring parameters, 21 inspection methods and intervals, acceptance criteria, 22 and evaluation of future operating experience.
23 The staff finds that ASR degradation and 24 related building deformation will be adequately managed 25 268 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 so that the intended functions will be maintained 1 through the period of extended operation.
2 It's been a long six years and the staff 3 can now conclude that, based on our review, the ASR 4 open item from 2012 is closed.
5 The next slide is just a summary of the 6 regulatory reasonable assurance conclusion.
7 Number one, the applica nt demonstrated 8 that proposed plant
-specific Aging Management Programs 9 will adequately manage the effects of aging due to ASR, 10 in accordance with the regulations in 10 CFR 54.29(a).
11 The license amendment ensures that 12 programs to evaluate and manage ASR will be added to 13 the current licensing basis.
14 The ongoing Regional oversight and the 15 71002 inspection concluded, from a Regional 16 perspective, that programs are effectively being 17 implemented today and will continue to be effectively 18 implemented through the PEO
. 19 And the license conditions that are 20 associated with the license amendment request 21 corroborate future expansion behavior, which will 22 ensure continued applicability of the large
-scale 23 testing program to Seabrook structures.
24 With that, I conclude the staff' s 25 269 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 presentation and we'd like to welcome your questions.
1 CHAIRMAN SKILLMAN: Angela, thank you very 2 much. Colleagues, any questions for the NRC staff at 3 this point, please? No questions from my colleagues?
4 Let me just do a headcount.
5 Vesna, any comments or anything you would 6 like to communicate at this point, please? Go ahead, 7 Vesna. 8 MEMBER DIMITRIJEVIC: No, I have asked the 9 questions I have been interested in. I think this was 10 a very comprehensive, absolutel y wonderful 11 presentation on everybody's contributions.
12 CHAIRMAN SKILLMAN: Okay. Dr. Corradini?
13 MEMBER CORRADINI: No, I agree with Vesna, 14 it was quite comprehensive.
15 CHAIRMAN SKILLMAN: Dr. Rempe?
16 MEMBER REMPE: No, I don't have any 17 additional comments. I d o want to thank the staff and 18 all of the folks associated with the Seabrook LAR who 19 presented, because I do think they gave very good, well 20 thought out presentations to elucidate the issue.
21 CHAIRMAN SKILLMAN: Dr. Riccardella?
22 MEMBER RICCARDELLA: I think what I've seen 23 represents a very impressive body of work. I think 24 that the presentations by the licensee and the staff, 25 270 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 as well as the documents that we've been provided to 1 review, provide us with adequate information for our 2 deliberations at the main Com mittee on this topic.
3 CHAIRMAN SKILLMAN: Thank you. Dr.
4 Kirchner? 5 MEMBER KIRCHNER: Just to thank the 6 applicant and the staff, as Pete said, quite thorough 7 and comprehensive.
8 I will reiterate my suggestion from the 9 closed session that as much of the material that we 10 saw today, which I found pretty thorough and complete, 11 that could be made available to the general public, 12 I just would encourage that.
13 CHAIRMAN SKILLMAN: Okay.
14 MEMBER KIRCHNER: I'm referring to 15 materials that were marked proprietary.
16 CHAIRMAN SKILLMAN: Thank you, Walt. Dr.
17 March-Leuba? 18 MEMBER MARCH
-LEUBA: Yes, I have a number 19 of comments. First, I'd like to say that, the staff 20 had done a heck of a job. I mean, you really have done 21 a fantastic job. And maybe you don't realize the two 22 things that I think you've done extraordinarily.
23 Number one, the Region identified a problem 24 that was not textbook. We're used to walking through 25 271 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 the plant and going through the procedures and they're 1 supposed to do something in 15 minutes and they did 2 it in 16, aha, we caught you.
3 You guys had an open mind and were asking, 4 what could possibly go wrong?, and identified something 5 that was not
-- that you were not looking for. So, 6 that is difficult to do and I congrat ulate you for doing 7 it. 8 On the Headquarters side, you also did 9 something good, because I wasn't there, but I'm pretty 10 sure the licensee, when confronted with the issue, said, 11 no never mind. Buildings move, sidewalks crack, what 12 are you talking about?
13 And you didn't take no, never mind, for 14 an answer, and pushed it and identified that this has 15 some safety significance and you have taken it to 16 conclusion.
17 And that is difficult to do also, so 18 congratulations. You all should go talk to your bosses 19 and ask for a raise. Not that it's going to happen, 20 but you've done a great job.
21 The licensee has also done a fantastic job.
22 I mean, I'm sure that it took a while to get into the 23 mode of actually responding, but when they did, they've 24 done incredible testing and th ey have a very good 25 272 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 program with AMPs and with calculations and I have, 1 not being an expert, I have great confidence that these 2 structures are going to work.
3 No, I have a lot more. Now, that's the 4 good side.
5 On the bad side, for th e staff, I'm not 6 sure that this is not a generic issue. I'm not sure 7 that all the other 100 plants out there, some of them 8 no have ASR issues.
9 So, I don't know, let's think about that 10 and see how we can communicate to them that there might 11 be a problem.
12 MR. DONOGHUE: One of the issues that we 13 have discussed before, related to subsequent license 14 renewal, is concrete degradation. And there's 15 continuing research on that.
16 And what we've
-- the Commission has agreed 17 that plants can provide a plant
-specific app roach to 18 that, and there's three other issues, to be able to 19 pursue subsequent license renewal.
20 So, there is generic work underway that 21 the industry's pursuing, because they would
-- it would 22 be easier to have a generic solution to that. So, I'll 23 just lea ve you with that.
24 So, there are other plants, as you well 25 273 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 know, there's other applications, they have to address 1 concrete and other issues on a plant
-specific basis 2 to obtain a subsequent license renewal approval.
3 MEMBER MARCH
-LEUBA: Okay. I'm glad to 4 hear that, because this morning, the answer I understood 5 was, nobody else has a problem. That's what I 6 understood when I raised the issue at 8:35 this morning.
7 And obviously, that's not the case, so I'm glad to 8 hear that.
9 Final item, I'm sorry, it's not that late, 10 we have an hour ahead of schedule. I understand we 11 are going to have a full Committee meeting on the license 12 renewal and are we going to recommend that? I do 13 recommend that we have it.
14 CHAIRMAN SKILLMAN: Well, let's take it one 15 step at a time. We are having a license renewal meeting 16 for the Seabrook Station on November 15.
17 This meeting was specifically crafted to 18 address alkali
-silica reaction, recognizing that there 19 are one, two, or three AMPs in the license renewal 20 appl ication that address this topic.
21 So, the intention for this meeting was to 22 get the ASR issue resolved for the Committee, prior 23 to our getting to November 15.
24 We're going to meet on November 15, we 25 274 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 already have the safety evaluation, I've been reassured 1 that we now have the final signed documents. That is 2 our review target for November 15.
3 And presuming that we clear November 15 4 without issues, we go to the December full Committee 5 meeting with the intention of writing a letter.
6 MEMBE R MARCH-LEUBA: Here is my question, 7 are we writing one letter or two?
8 CHAIRMAN SKILLMAN: We're going to discuss 9 that among ourselves or at P&P on Friday morning.
10 MEMBER MARCH
-LEUBA: Okay. And with that, 11 I yield the remainder of my time.
12 (Laughter.)
13 CHAIRM AN SKILLMAN: Dr. March
-Leuba, thank 14 you. Dr. Ballinger, sir?
15 MEMBER BALLINGER: I guess I'd like to sort 16 of echo what other people have said. I might add that 17 both the GALL
-SLR and the Expanded Materials 18 Degradation Assessment, EMDA, documents, also all 19 require now that ASR and everything be explicitly 20 identified
-- 21 CHAIRMAN SKILLMAN: Addressed.
22 MEMBER BALLINGER:
-- so, I don't think 23 we're going to have that issue any more. And lastly, 24 I still feel comfortable going to the Airfield Café 25 275 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 near Seabrook.
1 (La ughter.) 2 CHAIRMAN SKILLMAN: Thank you, Dr.
3 Ballinger. The distinguished Charlie Brown, Charlie?
4 MEMBER BROWN: I only had one observation, 5 probably being the least concrete familiar person on 6 the Committee.
7 I appreciated the NextEra and consultants 8 presenting of the data in what I would call English 9 and not burying it in very obscure jargonese, because 10 I actually understood what you were talking about as 11 you went through the analysis and stuff.
12 CHAIRMAN SKILLMAN: Minimum acronyms.
13 ME MBER BROWN: They did a good job and so 14 did the staff, in terms of their follow
-up on the stuff, 15 so I thought it was a good presentation for, and it 16 was clean for somebody who not necessarily an expert 17 in that field. So, I appreciated that and I had no 18 oth er comments other than that.
19 CHAIRMAN SKILLMAN: Thank you, Charlie.
20 Dr. Bley, by chance are you still with us, please?
21 Dennis, are you there, please? Let's proceed. We have 22 our consultant, Dr. Schultz. Steve?
23 MR. SCHULTZ: Thank you. My objectives for 24 the meeting were all met in the presentations today.
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-3701 (202) 234-4433 The summaries that were presented were 1 excellent and they were extremely helpful in clarifying 2 a number of issues, demonstrated comprehensive details, 3 demonstrating the approach developed for 4 investigat ion, testing, analysis, and monitoring 5 programs. 6 And the discussion really imparted that 7 the important features of the overall programs have 8 matured to implementation. And I was pleased that that 9 message was delivered today.
10 I was also pleased that NextEra clearly 11 is integrating the program into the site organization 12 at Seabrook. It's clear that the Station owns the 13 program and the ongoing resolution and monitoring for 14 the entire facility is in place and it's moving forward 15 in impl ementation.
16 I agree with the comment regarding the site 17 documentation on monitoring. It was a detailed slide 18 that was presented to us and we didn't go through it 19 in detail, but it clearly demonstrates that the 20 monitoring program is very well developed at Seabrook. 21 And the documentation that is being 22 provided for the program is going to be very valuable 23 moving forward, to allow the program to be successful, 24 because it's a very complex set of programs that come 25 277 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 together for this.
1 I also would like to really congratulate 2 the staff, as noted by Jose, for their involvement in 3 the inspection and oversight, for several years, 4 through here. Both the oversight and the documentation 5 related to it, in the inspection reports, and then, 6 carrying on into the safety evaluation.
7 It's very clear the level of detail and 8 the work that's gone into this review by the staff and 9 it shows in the detailed documentation that's been 10 developed for addressing this issue and going into the 11 license renewal safety evaluation as well.
12 I would just be repeating what I said 13 before, but it looks
-- the license condition that's 14 been put forward for the longer term evaluation of the 15 testing program versus what is going to be learned from 16 Seabrook in the next five years an d then, 15 years, 17 does look fairly complex to me.
18 And it's going to take a real investment 19 by NextEra to make that happen, I believe. And I'm 20 a little concerned that the experts that have 21 participated in our program today and in the 22 investigations over th e last five years may not be 23 available to move forward with that investigation, so 24 I hope they're doing a lot of mentoring for their staff 25 278 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 moving forward to make sure that that is covered 1 comprehensively when it comes to pass.
2 But thank you all for your pr esentations, 3 I've learned a lot.
4 CHAIRMAN SKILLMAN: Thank you, Steve. I 5 would like to make several comments before we go to 6 public comment. When we began this meeting, I 7 identified several things that I was very interested 8 in hear ing. 9 The first was to hear the staff and the 10 licensee communicate that they have a clear 11 understanding of the seriousness of the issue at 12 Seabrook Station.
13 That has been accomplished. I've heard 14 it from the staff, I've heard it from the licensee, 15 and I've heard it through the thoroughness of MPR and 16 SGH. 17 I communicated that I was looking or 18 listening for clarity regarding the scope of systems, 19 structures, and components affected by ASR. That has 20 been completed. It's clear in my mind that the licensee 21 and the staff understand the scope and understand the 22 importance of the scope.
23 I communicated that I was looking for 24 clarity regarding the extent of condition. That has 25 279 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 been fulfilled.
1 I communicated that I was listening for 2 a demonstration of the discipline. What I mean by that 3 is that what you do when you put on the seatbelt buckle 4 and get down and get busy and really get to the bottom 5 of the issue, the technical drive and the discipline 6 to understand the as
-found state and the prog ression 7 of the phenomenon. And it's clear in my mind that that 8 has been fulfilled.
9 And I was interested in the thoroughness 10 of the licensee's plans, actions, and commitments.
11 To Dr. Schultz's comment, I believe that that which 12 will be codified as a conse quence of the license 13 amendment will ensure that this endures for generations 14 to come. 15 I want to thank the staff, I want to thank 16 MPR, I want to thank SGH for their effort, very 17 comprehensive and very thorough. But I want to say 18 one or two other things.
19 I want to thank Theron for his effort to 20 put together a conference room that allowed us to do 21 this away from our normal conference space. So, 22 Theron, thank you, sir.
23 And to Kent, for all of his work to pull 24 this together. Thank you. I wanted to do this b efore 25 280 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 we go to public comment, because I don't know what might 1 be coming.
2 With that, is there any individual in the 3 room that would care to come to the microphone and make 4 a comment? I invite you to do so and I ask you to speak 5 clearly into the mic, pleas e come. 6 MR. NORD: Thank you. Wow, good evening.
7 I mean, this has been an amazing
-- 8 CHAIRMAN SKILLMAN: Would you please 9 introduce yourself?
10 MR. NORD: I'm sorry. I will say though, 11 that this has been an amazing thing to sit throug
- h. 12 My name is Chris Nord, N
-O-R-D. I live in Newbury, 13 Massachusetts.
14 I have lived within the Emergency Planning 15 Zone for Seabrook for a good part of my adult life and 16 I'm a founding member and board member of the C
-10 17 Research and Education Foundation in Newburyport, 18 Massachusetts.
19 We have operated the single largest 20 real-time citizens
-run radiation monitoring network 21 in the United States for 25 years, under contract with 22 the State of Massachusetts, their Emergency Management 23 Agency, I believe is where we are now. 24 We also have undertaken to monitor safety 25 281 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 at Seabrook, which is what got us involved years ago, 1 through discoveries of our researcher, the presence 2 of alkali-silica reaction at Seabrook, that has led 3 us to three different legal sessions concerning the 4 NRC. 5 One, a rulemaking petition. One, an 6 emergency enforcement action petition, which happened 7 two years ago. And in 2017, we were granted standing 8 before the Atomic Safety and Licensing Board, for one 9 overarching c ontention having to do with the license 10 amendment request.
11 And that contention has to do with the lack 12 of representativeness. We're challenging the 13 representativeness that NextEra claims that it has 14 established for the large
-scale testing protocol at 15 Ferg uson Labs.
16 So, my comments are going to be directed 17 toward helping clue you all in, so that you know who 18 we are, of the difficulties that we have with the license 19 amendment request and the order in which all of these 20 issues are coming out in the Nuclear Re gulatory 21 Commission through its various agencies.
22 And I have tried through the day to shorten 23 and shorten how I might get this done, because I know 24 it's very late. So, I'm going to shortcut a lot of 25 282 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 things. 1 We have submitted a document that came into 2 you all, highlighting some of our concerns, which you 3 will receive in writing, or have received digitally 4 already. So, let's see.
5 So, as I said, we have the overarching 6 contention challenging the representativeness of the 7 Ferguson larg e-scale testing. Among the
-- it's at 8 least seven features of the safety evaluation that I 9 saw, we intend to directly challenge.
10 They included an inherent bias in the 11 testing methodology, challenging the notion that the 12 Ferguson testing yields improved da ta on limit states 13 that apply to Seabrook.
14 Challenging the rationale offered in 15 answer to RAI
-T2, for the representativeness of 16 accelerated ASR. Challenging the sufficiency of an 17 independent internal peer review as a peer review in 18 the conventional sense.
19 And as an aside, I want to tell you that 20 we at the C
-10 Foundation feel a tremendous burden of 21 responsibility right now, because we don't see any 22 opportunity, other than the one that is presented, to 23 this larger process, by our intervention in this 24 proces s, to actually have a peer review.
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-3701 (202) 234-4433 This material is not being shown to the 1 wider scientific community to offer a peer review and 2 so, it falls to the expert witnesses that we are able 3 to bring to this, that are going to provide an 4 independent peer review.
5 Which is quite a burden for an organization 6 whose budget really concerns radiation monitoring.
7 This is a big thing for us to bite off. And I mean, 8 I'm not a scientist and none of us are scientists, we're 9 just doing the best we ca n with what we've got.
10 I just wanted to illustrate one of many 11 issues that we have and then, I'm leaving all the others 12 out. 13 The Section 3.2(a), which we saw in Page 14 29 of the draft safety evaluation, the rationale 15 expressed there for the use of accelerated ASR in the 16 Ferguson testing does not answer RAI
-T2, Request 1, 17 with regard to Seabrook structures.
18 To claim that the use of fast
-acting ASR 19 for research at Oak Ridge and NIST makes its 20 applicability as specifically representative of the 21 40-year-old concrete supporting structures sitting in 22 the uniquely harsh environment of the New Hampshire 23 Salt Marsh, is not an adequate scientific 24 justification.
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-3701 (202) 234-4433 It is important to note here that because 1 of the long
-term inundation of at least one structure, 2 the famous el ectrical cable tunnel, as it was called, 3 that was intended to be dry, Seabrook Station has 4 operated outside its design basis for its entire license 5 term. 6 If it is true that this reactor, being one 7 of the last commercial atomic plant s to be licensed, 8 is coincidentally the first U.S. reactor to be found 9 with alkali
-silica reaction, perhaps it behooves the 10 Nuclear Regulatory Commission and, by extension, ACRS, 11 with all respect, to look more closely at the Seabrook 12 Reactor itself to disc over what has caused this 13 exceptional circumstance and not to be persuaded by 14 the licensee to look away from Seabrook's own data in 15 favor of an unprecedented and remote testing protocol.
16 Okay. I'm going to mix a couple of 17 metaphors and then, I'm going to finish. What I want 18 all of you in this Committee to understand is that from 19 the point of view of the C
-10 Foundation, you all have 20 a freight train in your control that's rolling downhill.
21 And that freight train is occupying the 22 same track that we are, but we're moving much more 23 slowly. And that's because of the two different tracks 24 that we saw much earlier in the day that has this process 25 285 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 going along way before we have an opportunity to 1 litigate our case.
2 Therefore, I am not in a position to be 3 able to pr osecute our case in front of the ACRS today, 4 because we're nine months away from being ready to go 5 to court. 6 But in the meantime, you all are somehow 7 being called upon by what we believe is a skewed process 8 to consider having some k ind of a -- making some kind 9 of an advisory decision on the efficacy of this testing 10 protocol before we ever have a chance to litigate it.
11 And I mean, I just have to point out that 12 that is not a fair system. That is not a democratic 13 system. 14 So, the second metaphor, it has to do
-- 15 I'm going to give you a really short story. More than 16 30 years ago, a commercial atomic plant out on the edge 17 of the New Hampshire Salt Marsh was fully completed 18 with billions invested, before its evacuation plans 19 were ever adju dicated. 20 In fact, a majority of the towns within 21 the Emergency Planning Zone rejected the plans as 22 unfeasible, which we all believe actually they still 23 are, maybe even more so, because there are twice as 24 many people living there.
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-3701 (202) 234-4433 And FEMA's Region I Chief sided with the 1 towns. What happened? The head of the Federal 2 Emergency Management Agency was replaced, the towns 3 were ignored, and the Atomic Safety and Licensing Board 4 put the plant online.
5 For those of us working for the safety of 6 Seabrook's neighbors for many decades, it seems that 7 the cart has been put before the horse once again.
8 The goals of a for
-profit industry are 9 sometimes at odds with a fair and democratic process.
10 It is worse than unfortunate that the U.S. Nuclear 11 Regu latory Commission personnel concerned with 12 Seabrook's future are being pushed to consider a license 13 extension completely out of sequence with C
-10's 14 capability to give voice to crucial issues that bear 15 directly on the plant's qualification to continue 16 oper ating. 17 There are nine instances where the NRC 18 staff finds reasonable assurance that the design 19 parameters, including building deformation compression 20 flexure strains on reinforcement in the external 21 seismic strain will be met.
22 The phrase reasonable assuran ce is a 23 subjective one. Would not beyond a reasonable doubt 24 be a higher standard?
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-3701 (202) 234-4433 The goal of the NRC is to protect citizens 1 from exposure to some of the most toxic substances on 2 Earth, which is something that those of us that live 3 within the ingestion pathway for Seabrook, and many 4 of us live much closer, really take seriously.
5 Therefore, the most stringent standard should be 6 required. 7 Factoring in ASR as a design
-basis load 8 would bring Seabrook closer to design
-basis limits, 9 which would then become a causal factor in structural 10 failure brought about by internal and/or external 11 strain from beyond
-design-basis events, accident, 12 attack, natural disaster.
13 While 40 years ago, it might have seem 14 implausible and unnecessary to worry over such events, 15 we now know such worries are not unfounded, while the 16 consequences of such an event occurring in one's own 17 community are truly unfathomable.
18 C-10 urges the Advisory Committee on 19 Reactor Safeguards, and by extension, the NRC, not to 20 allow the erosion of margins of safety built into 21 Seabrook's supporting walls by design and not to allow 22 the erosion of trust of residents of our EPZ.
23 We ask the federal regulators charged with 24 protecting us to hold NextEra to a higher standard.
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-3701 (202) 234-4433 Lastly, we ask for assurance that the planned public 1 hearing on LAR 1603 be allowed to proceed before any 2 decision is made on Seabrook's request for a 20
-year 3 extension for the plant's operating license. Thank 4 you. 5 CHAIRMAN SKILLMAN: Thank you for co ming 6 to the microphone. Welcome to you and we respect your 7 participation here. Thank you.
8 MR. NORD: If you really do, give us a 9 chance. 10 CHAIRMAN SKILLMAN: Is there anyone else 11 in the room that would care to come to the microphone?
12 If so, would you pleas e come and introduce yourself?
13 Hearing none, on the phone line, is there 14 any individual out there? If so, would you simply say 15 hello? 16 MR. WALDEN: Hello, this is Scott Walden.
17 CHAIRMAN SKILLMAN: Good afternoon, sir.
18 Now, to Scott and to anyone else, would anyone wish 19 to make a comment, please? If so, announce who you 20 are and then, please make your comment.
21 MR. WALDEN: Okay. This is Scott Walden.
22 I'd like to make a comment. I'm from Southern Nuclear 23 and I am the Chairman of the NEI License Renewal Civil 24 Structural Working Group.
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-3701 (202) 234-4433 And I just wanted to say that, as an 1 industry, we are well aware of the alkali
-silica 2 reaction and what has occurred and going on with 3 Seabrook. 4 And it's a common topic that we have at 5 our meetings, to discuss ASR, how we're going to address 6 it in the future, and looking at how we want to look 7 at things that are, what I would say, are leading 8 indicators, has been discussed with closing up gaps 9 and things like that.
10 So, we're, as a group, we're well involved 11 and working with EPRI. As a matter of fact, we're 12 looking at submitting at all of our structural 13 monitoring procedures to EPRI and next year, EPRI will 14 be putting out a report with that information, looking 15 at how we can develop commonality within the ut ility 16 group. 17 CHAIRMAN SKILLMAN: Thank you for your 18 comment, sir. Is there anybody else out there that 19 would wish to make a comment? If so, would you please 20 introduce yourself and make your comment?
21 MR. OSSING: Hello, my name is Mike Ossing, 22 from Marlborough, Massachusetts. Just a couple of 23 quick comments.
24 I would like to commend the NRC staff on 25 290 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005
-3701 (202) 234-4433 the thoroughness of their review. I thought it was 1 detailed and it took eight years to go through it and 2 that's right on point.
3 Reminded that ASR is a reaction and it does 4 take a while. I think the key to the whole process 5 is a robust monitoring plan, which I believe NextEra 6 has in place.
7 And I appreciate the thoughtful 8 deliberation by the ACRS Subcommittee. Thank you.
9 CHAIRMAN SKILLMAN: Thank you, sir. Is 10 there anybody else out there that would like to make 11 a comment? If so, please identify yourself and please 12 make your comment. Hearing none, Theron, please close 13 the phone line.
14 Colleagues, one last chance for comment.
15 I want to go around one last time. Vesna, any comment?
16 MEMBER DIMITRIJEVIC: No.
17 CHAIRMAN SKILLMAN: None? Mike, you good?
18 MEMBER CORRADINI: Yes.
19 CHAIRMAN SKILLMAN: Joy, good?
20 MEMBER REMPE: No more comments, thank you.
21 CHAIRMAN SKILLMAN: Pete, good?
22 MEMBER RICCA RDELLA: I'm good.
23 CHAIRMAN SKILLMAN: Walt, good?
24 MEMBER KIRCHNER: No thank you.
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-3701 (202) 234-4433 CHAIRMAN SKILLMAN: Jose, good?
1 MEMBER MARCH
-LEUBA: No.
2 CHAIRMAN SKILLMAN: Dr. Ballinger?
3 MEMBER BALLINGER: No.
4 CHAIRMAN SKILLMAN: Honorable Charlie 5 Brow n? 6 MEMBER BROWN: I'm good.
7 CHAIRMAN SKILLMAN: Dr. Schultz?
8 MR. SCHULTZ: No additional comments, thank 9 you. 10 CHAIRMAN SKILLMAN: Ladies and gentlemen, 11 thank you very much, we are adjourned.
12 (Whereupon, the above
-entitled matter went 13 off the record at 6:24 p.m
.) 14 15 16 17 18 19 20 21 22 23 24 25 292 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
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-3701 (202) 234-4433 1 2 3 4 Evaluation and Management of Alkali Silica Reaction (ASR) at Seabrook Station October 31, 2018 Introduction and Background Speakers: Kenneth Browne
, NEE Seabrook Licensing Manager Michael Collins , NEE Seabrook Director of Engineering Edward Carley, NEE Seabrook Engineering Supervisor
2 The foundation for everything we do are the Values and Core Principles of our Nuclear Excellence Model
3 Key Personnel in Attendance:
NextEra Energy Seabrook NextEra Energy: *Eric McCartney, Regional Vice President
- Larry Nicholson, Director of Fleet Licensing
- Michael Collins, Director of Engineering
- Kenneth Browne, Licensing Manager
- Jaclyn Hulbert, Engineer
- Structures Monitoring Program
- Edward Carley, Engineering Supervisor
- David Robinson, Chemistry Manager
4 Key Personnel in Attendance:
MPR Associates, Inc. (MPR
) Personnel in Attendance:
- John Simons
- Amanda Card
- Christopher Bagley Key Efforts:
- Extent of Condition
- Interim Structural Assessment
- Large-Scale Testing Regarding Capacity *Monitoring and Assessment of Expansion Behavior
- Aging Management
5 Key Personnel in Attendance
- Simpson Gumpertz & Heger Inc. (SGH
) Personnel in Attendance:
- Dr. Said Bolourchi
- Liying Jiang *Dr. Andrew Sarawit Key Efforts:
- Concrete Technology
- Concrete testing & Petrography
- Inspections/Monitoring
- Methodology for Evaluating ASR-affected Structures
- ASR Load Factors
- Structural Evaluation
- Structural retrofit support
- Aging Management
6 Technical Consultants in Attendance Dr. Oguzhan Bayrak (PhD, PE, F ACI)
- Ferguson Structural Engineering Laboratory (FSEL)
Dr. Bruce Ellingwood (PhD, PE, NAE, F SEI, Dist M ASCE)
- Colorado State University Brian Brown (PE)
- NEE Seabrook, Retired Structural Engineering Supervisor Robert Schofield
- ENERCON 7 SEABROOK BACKGROUND
8 Seabrook Background
- Seabrook Station is a single unit Westinghouse 4
-loop pressurized water reactor with a General Electric turbine generator *Located in the town of Seabrook, New Hampshire
- Two miles west of the Atlantic Ocean
- Approximately two miles north of the Massachusetts state line
- Approximately 15 miles south of the Maine state line
- Reactor housed in a steel lined reinforced concrete containment structure which is enclosed by a reinforced concrete containment enclosure structure
- 3648 MWt Thermal Power; ~ 1,250 net megawatts electric
- Atlantic Ocean is the ultimate heat sink
- A Seismic Category I mechanical draft cooling tower provides additional safe shutdown capability.
9 N Seabrook Beach Hampton Beach Route 1 Seabrook Station 600 ac. marshland 300 ac. upland Seabrook
Background:
Plant Footprint
10 Seabrook
Background:
Plant Layout
11 Seabrook
Background:
Licensing Timeline Construction Permit (CPPR
-135) July 1976 Zero Power Operating License (NPF
-56) October 1986 Low Power Operating License (NPF
-67) May 1989 Full Power Operating License (NPF
-86) March 15, 1990 Commercial Operation August 1990 Operating License Transfer to FPL Energy (NextEra)
November 2002 Stretch Power Uprate (3587 MW)
February 2005 Zero Power Recapture (3.4 years)
December 2005 Measurement Uncertainty Uprate (3648MW)
May 2006 LR Application Submitted May 25, 2010 Operating License Expires March 15, 2030 12 Status of ASR Effort at Seabrook Station Completed a comprehensive effort to:
- Conduct large
-scale testing to understand the structural implications
- Develop methodology for evaluation of ASR
-affected structures
- Evaluate Seismic Category I structures
- Develop monitoring strategies for ASR-affected concrete and associated SSCs Demonstrated compliance
- Seismic Category 1 structures comply with proposed licensing basis in LAR *Modifications to several structures are underway Actively tracking developments in ASR research NextEra Energy Seabrook has implemented an effective program for evaluating and managing the impacts of ASR on affected concrete structures and associated SSCs
13 Purpose of Presentation Describe the comprehensive approach for addressing ASR at Seabrook Station Provide an overview of the technical basis for the ASR management approach
-Large-Scale Testing
-Methodology for evaluating ASR
-affected structures Summarize implementation of the Structures Monitoring Program for aging management of ASR
-affected structures
14 Presentation Outline ASR Background Approach for Addressing ASR Technical Basis for ASR Management Approach
- Large-Scale Test Programs *Structural Evaluation Methodology for ASR
-Affected Structures Implementation of ASR Management Approach
- Structures Monitoring Program
- Status of Relevant Licensing Actions
- License Amendment Request (LAR)
- License Renewal Application (LRA)
Conclusions and Closing
15 BACKGROUND OF ASR AT SEABROOK STATION 16 ASR
Background:
Discovery at Seabrook Station Initial Diagnosis
- Identified Pattern Cracking in the B Electrical Tunnel
- Performed Petrography on Cores (Confirmed ASR) *Conducted Material Property Testing on Cores
17 forms alkali cement + reactive aggregate expansive gel K+ Na+ cracking of the aggregate and paste
+ H 2 O gel gel SiO 2 SiO 2 SiO 2 OH- OH- ASR
Background:
Alkali
-Silica Reaction (ASR)
18 ASR in Country's Infrastructure Photos courtesy of SGH
19 Reactive Aggregate Moisture Alkali ASR
Background:
Causes of ASR *Preventive measures taken during plant construction to prevent the development of ASR
-Aggregate reactivity testing
-Low alkali cement
- Current state of knowledge
-Aggregate reactivity testing oASTM test methods used during plant construction not reliable for slow reacting aggregates
-Limiting alkali content of cement oNot sufficient by itself to prevent ASR
20 ASR
Background:
Visual Indications of ASR
21 ASR
Background:
Implications of ASR Reduction in material properties and their effect on structural capacity
- Compressive strength
- Tensile strength
- Modulus of elasticity Effect of ASR
expansion on structural demands
- Structural deformation Potential impact to plant systems and components
22 Approach for Addressing ASR at Seabrook Station Large-Scale Testing Field Data ASR Load Factors Structural Evaluation Structural Capacity Part 50 Part 54 Structures Monitoring Program Structural Demand Structural Evaluation Updates Structural Evaluation Methodology UFSAR 23 Conclusions Large-Scale Test Programs
- No adverse impact of ASR on structural capacity within test limits
- Limits have been established for monitoring of plant structures Evaluation Methodology
- Defined process that considers the impact of ASR on both structural capacity and structural demands Structural Evaluations
- Demonstrate Seismic Category I structures comply with licensing basis Structures Monitoring
- Comprehensive program addresses ASR expansion, building deformation and impact on systems/components NextEra Energy Seabrook has implemented an effective program for evaluating and managing the impacts of ASR on affected concrete structures and associated SSCs
Evaluation and Management of Alkali Silica Reaction (ASR) at Seabrook Station October 31, 2018 Methodology for Structural Demand Evaluation of ASR-Affected Structures Speakers: Simpson Gumpertz & Heger Inc. (SGH) Dr. Said Bolourchi, Glenn Bell, Matthew Sherman Supporting Personnel: Dr. Bruce Ellingwood 2 Structural Evaluation Methodology Define a consistent and repeatable analysis and evaluation methodology for all Seismic Category I structures Apply the methodology to evaluate structures to show: Structural Capacity No impact on Code capacity Change in stiffness relates to the prestressing effect Structural Demand Include ASR loads in UFSAR load combinations Field data for ASR status Modeling to account for ASR-induced prestressing 3 Why does ASR Change the Demand? If concrete is unrestrained, ASR causes expansion in the concrete, but no forces develop in the structure. If concrete is restrained, forces develop in the structure. This restraint can come from: Reinforcement Other segments of the same structure Adjacent structures Surrounding bedrock These forces must be considered, as they were not part of the original design basis defined in the UFSAR. ASR-affected structures must be evaluated 4 Structural Evaluation Methodology for ASR-Affected Structures Presentation Outline Evaluation of all Seismic Category I structures at Seabrook is based on UFSAR and defined in the Methodology Document Structural Evaluation Methodology: ASR Loading and Load Factors Methodology Document Methodology Document provides details for collecting field data and evaluating all Seismic Category I structures at Seabrook Station 5 ASR Load Factors Supplement the original design load effects with ASR loads, while maintaining the level of structural performance implicit in the original design criteria and codes Determine the appropriate ASR load factors to supplement ASME Section III 1975 and ACI 318-71 load combinations 6 Load Factor Principles All Category I Structures other than Containment Building ACI 318-71 Containment Building ASME Section III 1975 Allowable Stress Design Primary objective: Limit stresses in concrete and steel reinforcement. Strength Design Primary objective: Assure adequate strength.
7 CONTAINMENT BUILDING ASME SECTION III 1975 8 ASME Section III 1975 Service Load Conditions: Construction and normal plant operation conditions that act frequently. Concrete stresses well below compressive strength, steel stresses well below yield. Factored Load Conditions: Severe and extreme environmental and abnormal conditions that act infrequently. Permitted stresses higher than for Service Load Conditions but generally below concrete compression and steel yield strengths. Containment Building 9 Containment Building Fa = allowable stress = Fcr Fcr = critical stress = stress partial factor of safety Si = Load Effects (Dead, Live, Earthquake, ASR, etc.) = Load Factors associated with each Load Effect Loads are deterministic: established by positing various scenarios. Most load factors = 1.0. Some 1.25 to 1.5 for severe environmental or abnormal condition load combinations.
10 Develop ASR loads that have a very small likelihood of exceedance and use an ASR load factor of 1.0 Consistent with the deterministic philosophy used in the development of ASME Table CC-3230-1 Containment Building 11 Methodology Map the Containment Building into the four zones of ASR severity (Containment Building has only Zone 1 ASR) Apply to the entirety of each zone an ASR strain corresponding to the upper limit of CI in that zone and increase it by 25% Apply to this conservative ASR loading a load factor of 1.0 Zone 1 No ASR in Zone 3 Zone 3 Zone 4 0.0 mm/m mm/m mm/m Zone 1 No ASR in Zone 4 No ASR in Zone 2 0.5 0.6 1.0 0.1 Applied ASR at Zone 1 = 0.6 Zone 2 mm/m Containment Building 12 Schematic Illustration Containment Building Equipment Hatch 13 Why this Approach is Conservative The highest level of strain in each zone is applied to the entire zone An additional 25% margin is added to that highest level of strain The Large Scale Testing Program demonstrated that, on average, CI measurements conservatively predict ASR strain The literature shows that ASR strains measured at the concrete surface over predict strains at reinforcement depth For each load combination, a conservative value of ASR strain is applied for each ASR zone in combination with a load factor of 1.0.
14 SEISMIC CATEGORY I STRUCTURES OTHER THAN CONTAINMENT BUILDING ACI 318-71 15 Category I Structures Other Than Containment Building ACI 318-71 Strength is checked via code equations that assess a reinforced loading conditions.
16 Si = Load Effects (Dead, Live, Earthquake, ASR, etc.) = Load Factors associated with each Load Effect R = strength reduction factor Category I Structures Other Than Containment Building Load factors for strength checks generally between 1.4 and 1.7, but in load combinations involving wind, seismic, and accident conditions they may be lower.
17 Load Factors of ACI 318-71 Ellingwood et al. established the inherent reliability of ACI 318-71 for use in probability-based design Adopt the same probabilistic approach to establish ASR load factors for use with ACI 318-71 Average reliability indices () found in NBS study are used as basis for calculation of ASR load factors: For gravity load combinations: 3.0 Load combinations with wind: 2.5 For load combinations including the Operating Basis Earthquake: 1.75 18 Approach for Application of ACI 318-71 to Category I Structures Other than the Containment Building For each zone determine ASR strains from CI statistics gathered over those zones in the entire plant Map the four ASR severity zones onto each structure Apply an ASR strain corresponding to the mean value of CI measured in each zone Apply a probabilistically determined load factor as described in the following slides Zone 1 Zone 2 Zone 3 Zone 4 CI < 0.5 mm/m mm/m mm/m mm/m 19 Calculation of ASR Load Factors Input Variable How Addressed Target reliability, Based on NBS Report for each load combination as previously described Probability distribution of structural resistance Based on NBS Report Probability distribution of non-ASR load effects Based on NBS Report Probability distribution of ASR load effects From statistics of CI measurements taken at the plant Ratio of ASR load effects to total load effects, Kasr Representative values calculated for each ASR zone Calculation that finds the ASR load factor that results in the target reliability for each type of load combination 20 ASR Load Factors for Use with ACI 318-71 Notes: Per ACI 318-71, for load combinations involving differential settlement, creep, shrinkage, or temperature change, load factors may be reduced by 25% but may not be less than 1.0. Load Combination ASR Load Factor Zone 1 Zones 2-4 Static 2.00 1.60 Wind 1.70 1.36 OBE 1.30 1.04 21 Key Conclusions Regarding ASR Load Factors ASR load factors were developed to: Be added to UFSAR design load combinations Be consistent with the underlying philosophy of the original design criteria and codes ASR load factors maintain the level of reliability and margin of safety inherent in the codes of record.
22 Independent Review by Dr. Bruce Ellingwood For the Containment Building the methods employed for revising the load combinations to account for the structural actions due to ASR are entirely consistent with the deterministic approach to safety assurance historically taken in developing the ASME Code. For those Category I structures other than the Containment Building, the proposed modifications to the original design load combinations to account for the structural actions due to ASR will maintain the target reliability indices provided by the load combinations of ACI 318-71. This conclusion is based, in part, on independent calculation checks of reliability indices.
23 Field Data 24 Use of Field Data Analysis Field Data (Observations & Measurements) Data Interpretation 25 Field Data Overview Observations: Non-quantifiable information and guidance Measurements: Quantifiable information and data used directly in analysis Specialty Testing: Supporting or interpretive information and data 26 OBSERVATIONS 27 Field Data Observations: Visual, Sounding Cracks Enhanced with Chalk 28 Field Data Observations: Crack Patterns and Relative Movement Diagonal Cracks (Enhanced with Chalk) Movement of Flex Joint/Connector 29 EXPANSION MEASUREMENTS 30 Field Data Expansion Measurements: Cracking Index Cracking Index (CI) and Combined Cracking Index (CCI) Optical measurement Provides indication of ASR expansion-to-date 31 Field Data Expansion Measurements: Cracking Index Lay out measurement line Measure crack widths where they cross the line Add together measured widths Divide by total length w1 w2 L 32 Field Data Expansion Measurements: Cracking Index example Area with suspect ASR cracking 33 Field Data Expansion Measurements: In-Plane Expansion In--to- Higher-precision mechanical measurement Used in monitoring program for measuring ongoing changes 34 Field Data Expansion Measurements: Through-Thickness Expansion Used in monitoring program for confirmation that the structure and associated analyses remain within the bounds of the FSEL testing.
35 DEFORMATION MEASUREMENTS 36 - EL (-- EL (-- EL (-- FUEL STORAGE BLDG. PAB RCA TUN. EL (-- - - Concrete backfill Rock CEVA 20 10 0 20 Concrete Backfill The station was built into the excavated bedrock. Construction used concrete as backfill between the final structure and the excavation face. Backfill concrete is of the same type and composition as the structural concrete. Section Cut View 37 Field Data Deformation Measurements Plumbness measurements Wall structure Levelness measurements Slab structure 38 Field Data Seal/gap width measurements Annulus width measurements 39 SPECIALTY TESTING 40 Field Data Specialty Testing: Petrography To investigate if in-plane expansion is caused by mechanisms other than internal ASR expansion 41 Field Data Specialty Testing: Petrography Petrography to determine expansion mechanisms 42 Key Conclusions Regarding Field Data Field Data provide: Input data, feedback, and correlation to support modeling Reference values for future monitoring in Structural Monitoring Program Field data support evaluation and future monitoring.
43 Structural Evaluation Methodology Define a consistent and repeatable analysis and evaluation methodology for all Seismic Category I structures Establish threshold limits for potential future ASR expansion 44 ASR Structural Evaluation Process Methodology Document Load combinations and load factors Material properties Graded analysis approach Codes supplements Analysis Approach Threshold Limits Structural Evaluation Repeatable analyses process Graded approach field data Design margin for future ASR expansion Structures Monitoring Program Parameters monitored and frequency Trending Action if approaching threshold limits UFSAR (As Amended by the License Amendment Request) 45 Threshold Definition The threshold limit,), is additional margin to accommodate demands associated with future ASR growth. Where: R = Nominal strength = Capacity reduction factor = Original design load (Dead, Live, Earthquake, etc.) = ASR Load = Load Factors associated with each of original design load = Load Factor associated with ASR load kth = Threshold Factor ) Capacity Sum of factored design-basis loads Factored ASR load 46 Field Data Walkdown observations Graded approach for field data collection Typical Field Data include In-plane strain: CI, CCI, and Pin-to-pin Changes in seismic isolation gaps Structural deformation Structural distress Crack width Adjusted in-plain strain for: Cracks not indicative of ASR which could be due to: pressurization, temperature, differential ASR between regions, structural deformation, other design loads. Petrography confirmation 47 Graded Analysis Approach Select Analysis Stage Review Design Documents Initial Walkdown Stage One Original design demands Conservative ASR Original design demands ASR with finite element analysis Stage Two Correlate finite element model with field data All demands using finite element analysis Stage Three 36 Months Monitoring 18 Months Monitoring 6 Months Monitoring Review SMP Data Most Conservative Evaluation Conservative Evaluation Refined Evaluation 48 Stage Three Analysis Stage Three Correlate Finite Element Model with field data Use FEM to calculate demands for original loads and ASR loads Increase demands by threshold factor for future ASR growth Meets licensing basis as amended by LAR Threshold limits, reference values Monitoring every 6 months Is Demand No Retrofit Yes Re-evaluation No 49 Correlating Analysis Model to Field Observation Containment Enclosure Building Analysis Input: Analysis Method: Finite Element Analysis Analysis Output: Correlate to field data ASR CI Measurements, CEB Concrete backfill pressure due to ASR expansion Other sustained loads Compare deformation Compare strain + + Azimuth Meridional Strain 50 Key Attributes of Modeling General purpose finite element analysis software ANSYS is used for modeling structures. Internal ASR effects on reinforced concrete structures are simulated: Prestressing effects are captured by applying CI measured strain to concrete portion of reinforced concrete elements. Concrete backfill expansions are captured by vertical and lateral pressures applied to structure. Effects of structural cracking are captured by reducing member section properties.
51 The impacts of ASR expansion of concrete backfill are back-calculated by correlating structural responses to field data. Direct concrete backfill testing and strain measurements are not feasible because of inaccessibility. Concrete Backfill Simulation - EL (-- EL (-- EL (-- FUEL STORAGE BLDG. PAB RCA TUN. EL (-- - - Concrete backfill Rock CEVA 20 10 0 20 Section Cut View 52 Set lateral pressure equal to overburden pressure Reduce lateral pressure to simulate overall deformations Reduce lateral pressure to simulate flexural crack initiation when structural cracks are not observed Concrete Backfill Lateral Pressure 53 Acceptance criteria remain as original Code of Record (ASME Section III 1975; ACI 318-71) as supplemented by the LAR LAR Code Supplements Supplements Supplemented Document 1 Add the ASR load and load factors to UFSAR load combinations UFSAR & ACI 318-71 ASME Section III 1975 2 Code-defined strengths not impacted for members affected by ASR expansion ACI 318-71 ASME Section III 1975 3 Analyze shear-friction capacity per ACI 318-83, Section 11.7 ACI 318-71 4 Reduce section property to 50% of gross section property to account for flexural cracking ACI 318-71 5 Reduce axial and shear stiffness to account for cracking ACI 318-71 54 Threshold Parameters Structure specific threshold parameters are selected for structural monitoring program Selected threshold parameters can be quantitative and qualitative parameters Structure specific threshold parameters are a subset of parameters defined in Methodology Document including: In-plane expansion Through-thickness expansion Seismic joint width Structural deformation Crack lengths and widths 55 Key Conclusions of Structural Evaluation Methodology Structural Evaluation Methodology provides: ASR load factors that maintain the level of reliability inherent in the codes of record Repeatable graded approach for analysis and evaluation process Threshold factor, parameters, and monitoring frequency Repeatable analysis and evaluation process applicable for all Seismic Category I structures at Seabrook 56 Structural Evaluation Evaluate each structure using the Structural Evaluation Methodology Establish ASR threshold limits, parameters, baseline values, and frequency of monitoring for each structure Structural Capacity Structural Demand 57 All Seismic Category I structures are evaluated: Confirm structure meets Code of record. Determine Threshold Factor for each structure, which is the margin available to accommodate future ASR expansion. Define parameters, reference values, and limits to be monitored, and monitoring frequency. Identify structural areas that may require enhanced monitoring or retrofits. Evaluation status: Status of Evaluation Packages Number of Evaluation Packages Analysis Stage Threshold Factor One Two Three Completed 19 7 6 6 1.2 3.7 In progress 8 1 4 3 TBD Evaluations of Seismic Category I Structures 58 Key Conclusions of Structural Evaluation Seismic Category I structures are evaluated to meet acceptance requirements of UFSAR and the Structural Evaluation Methodology Provided ASR threshold factor, parameters, reference values, and monitoring frequency. Defined action required for structural members. Seabrook Seismic Category I Structures are evaluated to meet the UFSAR and Structural Evaluation Methodology requirements.
Evaluation and Management of Alkali Silica Reaction (ASR) at Seabrook Station October 31, 2018 Implementation of ASR Management Approach at Seabrook Station Speakers: Jaclyn Hulbert, NEE Seabrook Engineer Structures Monitoring Program Edward Carley, NEE Seabrook Engineering Supervisor Michael Collins, NEE Seabrook Director of Engineering Kenneth Browne, NEE Seabrook Licensing Manager 2 Current Status at Seabrook Station Presentation Outline Structures Monitoring Program Monitoring Efforts Monitoring Parameters and Acceptance Criteria Monitoring Locations ASR Progression and Expansion at Seabrook Station Current Level of ASR Progression Status of Relevant Licensing Actions License Amendment Request (LAR) License Renewal Application (LRA) 3 STRUCTURES MONITORING PROGRAM 4 Structures Monitoring Program Large-Scale Testing ASR Load Factors Structural Evaluation Structural Capacity Part 50 Part 54 Structures Monitoring Program Structural Demand Structural Evaluation Updates Structural Evaluation Methodology UFSAR Field Data 5 Structures Monitoring Program Overview Comprehensive Structures Monitoring Program that incorporates identification, evaluation, and monitoring of ASR-affected structures and associated SSCs ASR Monitoring Building Deformation Monitoring Equipment Impacted by Structural Deformation Monitoring Training program to increase awareness of ASR expansion and ASR-induced building deformation at Seabrook Station Web-based training for all personnel badged at Seabrook Focused training for departments that are inside plant structures on a frequent basis 6 Structures Monitoring Program Overview 7 Structures Monitoring Program Overview 8 SSCs attached to ASR-affected structures are monitored at least every two years to ensure functionality is not lost. Corrective action is taken if an adverse condition is noted. Monitoring Parameters and Acceptance Criteria for ASR-Affected Concrete and Associated SSCs Parameter Acceptance Criteria Frequency Expansion In-Plane Through-Thickness Volumetric Limits from the Large-Scale Testing Based on the level of in-plane expansion In-plane: 30, 18, or 6 month basis Through-thickness and Volumetric: 6 month basis Structural Deformation Seismic Gaps Annulus Width (CEB) Plumbness In-Plane Expansion Observations Sounding Thresholds from the Structural Evaluations (Building-Specific) Based on results from the Structural Evaluation (Building-Specific) 36, 18, or 6 month basis 9 CCI/In-Plane Expansion Grids Total of 136 locations for ASR in-plane expansion monitoring 21 additional grids have been established for deformation monitoring only Extensometer/Through-Thickness Expansion Total of 48 currently installed ~ 200 cores taken for material property testing (compressive strength and elastic modulus) Expansion to date was determined using the modulus correlation methodology Monitoring Locations 10 Deformation Monitoring Locations 24 structures currently monitored Monitoring Crack Gauge Measurements Annulus Measurements (between CEB and Containment) Seismic Gap Measurements (between adjacent structures) In-plane expansion 11 ASR Progression at Seabrook Station Expansion levels are within Large-Scale Testing limits Structures within Thresholds from the Structural Evaluations Expansion levels Deformation Expansion at Seabrook Station is slow Monitoring intervals are sufficient to ensure that limits are not approached prior to the next inspection interval 12 STATUS OF RELEVANT LICENSING ACTIONS 13 License Amendment Request (LAR) Rationale for LAR Original design basis did not include consideration of ASR loads No approved guidance on how to address degradation associated with ASR Function of the LAR Incorporates Evaluation Methodology and Large-Scale Test Program results Includes provisions for monitoring Status: Pending Submitted in August 2016 Draft SE in September 2018 14 License Renewal Application (LRA) ASR monitoring and management efforts in the Structures Monitoring Program (SMP) are carried forward in the Aging Management Programs (AMP) Structures Monitoring Program ASR AMP Building Deformation AMP (also considers SSC functionality) Status: Pending Subcommittee Meeting November 15, 2018 Full Committee Meeting December 6, 2018 15 Open Item Structures Monitoring Program OI 3.0.3.2.18-1 Aging management of concrete structures affected by Alkali-Silica Reaction (ASR). Resolution LRA updated to augment existing Structures Monitoring Program by addition of plant specific Alkali-Silica Reaction (ASR) and Building Deformation (BD) Aging Management Programs. Aging management of ASR has been integrated into the Section XI IWL Program. Inspection, tracking and evaluation are in accordance with guidance of ACI 349.3R. NextEra has implemented a program that effectively evaluates and manages the aging effects of ASR on affected concrete structures and associated SSCs 16 CONCLUSIONS 17 Approach for Addressing ASR at Seabrook Station Large-Scale Testing Field Data ASR Load Factors Structural Evaluation Structural Capacity Part 50 Part 54 Structures Monitoring Program Structural Demand Structural Evaluation Updates Structural Evaluation Methodology UFSAR 18 Evaluation Stage Threshold Factor Action Required Containment Internal Structures 1 No ASR Service Water Access Vault 1 No ASR Containment Building (CB) 1 1.8 Containment Equipment Hatch Missile Shield 1 1.5 Containment Enclosure Ventilation Area and RCA Tunnel 1 3.0* Relieve rebar stress on North wall (design is completed) Safety-related Electrical Manholes (7 units) 1 3.0 Electrical Cable Tunnel (North) 1 1.3* Enhanced monitoring and develop retrofit for future bracing the of the walls Condensate Storage Tank Enclosure 2 1.6 Pre-Action Valve Building 2 1.3 Main Steam & Feedwater Pipe Chase -West & Personnel Hatch 2 1.8 Main Steam & Feedwater Pipe Chase - East & Hydrogen Recombiner Room 2 1.5 Primary Auxiliary Building 2 1.5* Reevaluate or retrofit the below grade walls at elev. 7 Safety-related Electrical Manholes (6 Units) 2 1.5 to 1.7 Containment Enclosure Building (CEB) 3 1.3 Missile shield CEB to CB Seismic Gap restored Control Room Makeup Air Intake Structure 3 1.4 Residual Heat Removal (RHR) Equipment Vault 3 1.2 Fuel Storage Building 3 1.2 Mechanical Penetration 3 1.5* Retrofit north and south walls between elevs. - Service Water and Circulating Water Pumphouse 3 1.4 Completed Seismic Category I Structural Evaluations
- After proposed/completed action 19 Conclusions NextEra completed a comprehensive effort to: Conduct large-scale testing to understand the structural implications ASR Develop methodology for evaluation of ASR-affected structures Evaluate ASR-affected structures Develop monitoring strategies for ASR-affected concrete and associated SSCs Structural Evaluations Demonstrate Seismic Category 1 structures comply with licensing basis NextEra has implemented a program that effectively evaluates and manages the impacts of ASR on affected concrete structures and associated SSCs 20