ML19325D909

NRC Staff Proposed Findings of Fact and Conclusions of the Law for the Admitted Contention

ML19325D909
Person / Time
Site:	Seabrook
Issue date:	11/21/2019
From:	Jennifer Scro, Jeremy Wachutka NRC/OGC
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
50-443-LA-2, ASLBP 17-953-02-LA-BD01, RAS 55422
Download: ML19325D909 (104)

Text

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of NEXTERA ENERGY SEABROOK, LLC Docket No. 50-443-LA-2 (Seabrook Station, Unit 1)

NRC STAFF PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW FOR THE ADMITTED CONTENTION Jeremy L. Wachutka Jennifer Scro Counsel for NRC Staff November 21, 2019

TABLE OF CONTENTS PAGE TABLE OF AUTHORITIES ......................................................................................................... iii I. INTRODUCTION .............................................................................................................1 II. FINDINGS OF FACT .......................................................................................................6 A. The Discovery of ASR at Seabrook and NextEras Development of the Seabrook ASR Expansion Monitoring Program and the Seabrook Structure Deformation Monitoring Program ..........................................................6 B. The LAR and its Separate ASR Expansion Monitoring and Structure Deformation Monitoring Programs ......................................................25

a. The ASR Expansion Monitoring Program ............................................... 28

b. The Structure Deformation Monitoring Program ..................................... 30 C. The LSTP, Why It Was Needed as the Basis for the ASR Expansion Monitoring Program, and Why Large-Scale Testing is an Appropriate Approach ................................................................................32 D. The LSTPs Representativeness of the Progression of ASR at Seabrook .......... 40

a. Board Findings on Harvesting Concrete from Seabrook Station, Unit No. 2 ...............................................................................................40

b. Board Findings on the Scaling and Boundary Conditions of the LSTP Test Specimens ..................................................................41

c. Board Findings on the LSTPs Representativeness of the Seabrook Concrete Aggregates .............................................................44

d. Board Findings on the LSTPs Representativeness of the ASR Gel at Seabrook .....................................................................................50 E. The Representativeness of the LSTPs Program Elements ................................ 53

a. Board Findings on the Representativeness of the Shear Test Program ...............................................................................54

b. Board Findings on the Representativeness of the Anchor Test Program .............................................................................56

c. Board Findings on the Representativeness of the Reinforcement Anchorage Test Program................................................57

ii

d. Board Findings on the Representativeness of the Instrumentation Test Program ................................................................60 F. The Adequacy of the Seabrook ASR Expansion Monitoring Programs Monitoring, Acceptance Criteria, and Inspection Intervals Derived from the LSTP....................................................................................................63

a. Board Findings on the Use of the CI/CCI Method ................................... 67

b. Board Findings on the Possibility of Delamination Cracks Without Surface Indication in Seabrook Structures ................................. 70

c. Board Findings on Testing to Maximum ASR Expansion ........................ 74

d. Board Findings on Knowing the Rate of ASR Expansion at Seabrook ..................................................................75

e. Board Findings on the Use of the Correlation Equation to Calculate Through-Thickness Expansion to Date ...................................................77 G. NextEras Implementation of the Structure Deformation Monitoring Program is Not Within the Scope of this Proceeding .......................................... 82 H. Board Findings on NextEras Implementation of the Structure Deformation Monitoring Program ...........................................................................................86

a. Board Findings on the Use of Linear Elastic Analysis ............................. 87

b. Board Findings on the Potential for NextEra to Use a Probabilistic-Based Analysis Instead of its Codes-Based Approach ....... 92 III. CONCLUSIONS OF LAW..............................................................................................93

iii TABLE OF AUTHORITIES Page ADMINISTRATIVE DECISIONS Commission AmerGen Energy Co., LLC (Oyster Creek Nuclear Generating Station),

CLI-09-7, 69 NRC 235 (2009) ......................................................................................... 96 n.559 Crow Butte Res., Inc. (In Situ Leach Facility, Crawford, Nebraska),

CLI-15-17, 82 NRC 33 (2015) ......................................................................................... 97 n.561 Duke Power Co. (Catawba Nuclear Station, Units 1 and 2),

CLI-83-19, 17 NRC 1041 (1983) ..................................................................................... 96 n.558 Entergy Nuclear Operations, Inc. (Palisades Nuclear Plant),

CLI-15-22, 82 NRC 310 (2015) ....................................................................................... 94 n.545 Atomic Safety and Licensing Appeal Board Consumers Power Co. (Midland Plant, Units 1 and 2),

ALAB-283, 2 NRC 11 (1975) ........................................................................................... 96 n.558 Pac. Gas & Elec. Co. (Diablo Canyon Nuclear Power Plant, Units 1 and 2),

ALAB-763, 19 NRC 571 (1984) ....................................................................................... 97 n.560 Tennessee Valley Authority (Hartsville Nuclear Plant, Units 1A, 2A, 1B, and 2B),

ALAB-463, 7 NRC 341 (1978);

reconsideration denied, ALAB-467, 7 NRC 459 (1978) ................................................... 97 n.560 Atomic Safety and Licensing Board NextEra Energy Seabrook, LLC (Seabrook Station, Unit 1),

LBP-17-7, 86 NRC 59 (2017) ............................................................................................ passim STATUTES Atomic Energy Act of 1954, as amended, § 29, Advisory Committee on Reactor Safeguards; composition; tenure; duties; compensation (42 U.S.C. § 2039) (Nov. 10, 1998) ................................................................. 23 n.104, 37 n.182 REGULATIONS 10 C.F.R. § 2.325............................................................................................................ 96 n.558 10 C.F.R. § 2.340(a)(2)(ii) ............................................................................................... 25 n.117

iv 10 C.F.R. Part 50, Appendix A .......................................................................................... passim 10 C.F.R. Part 50, Appendix B .......................................................................................... passim 10 C.F.R. § 50.40(a) .................................................................................................................93 10 C.F.R. § 50.57(a)(3) .............................................................................................................93 10 C.F.R. § 50.58(a) ....................................................................................................... 23 n.105 10 C.F.R. § 50.90......................................................................................................................93 10 C.F.R. § 50.92(a) .................................................................................................................93 10 C.F.R. § 54.25............................................................................................................ 23 n.105 FEDERAL REGISTER NOTICES NextEra Energy Seabrook, LLC; Seabrook Station, Unit No. 1, License amendment; issuance, 84 Fed. Reg. 9564 (Mar. 15, 2019) ................................................................................. 25 n.117 NextEra Energy Seabrook, LLC; Seabrook Station, Unit No. 1, License renewal and record of decision; issuance, 84 Fed. Reg. 9563 (Mar. 15, 2019) ................................................. 25 n.118 MISCELLANEOUS ACRS Membership, https://www.nrc.gov/about-nrc/regulatory/advisory/acrs/membership.html (last visited November 21, 2019) ..................................................................... 37 n.184, 39 n.197 Letter from Eric McCartney, NextEra, to NRC, Seabrook Station, License Renewal Application Relating to the Alkali-Silica Reaction (ASR) Monitoring Program (Aug. 9, 2016) (LRA Supplement) ..................................................................................... 17 n.76 Letter from Paul O. Freeman, Site Vice President, NextEra, to NRC, Seabrook Station Application for Renewed Operating License (LRA) (May 25, 2010) ...... 6 n.21 Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station, Response to Request for Additional Information, NextEra Energy Seabrook License Renewal Application, Aging Management Programs (Dec. 2010 Response to RAI) (Dec. 17, 2010) ............................. 6 n.22 Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station, NextEra Energy Seabrook License Renewal Application, Structures Monitoring Program Supplement-Alkali-Silica Reaction (ASR) Monitoring (May 16, 2012)..................................... 10 n.39, 21 n.93 Letter from Richard Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information Related to the Review of the Seabrook Station License Renewal Application - Aging Management Programs (Nov. 2010 RAI) (Nov. 18, 2010) ....... 6 n.22, 8 n.31

v Letter from Richard A. Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information Related to the Review of the Seabrook Station License Renewal Application (Mar. 17, 2011) ................................................................................................................... 8 n.31 Letter from Richard A. Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information for the Review of the Seabrook Station License Renewal Application (June 29, 2011) ................................................................................................................... 8 n.31 Safety Evaluation Report Related to the License Renewal of Seabrook Station, Docket No. 50-443, NextEra Energy Seabrook, LLC (LRA SER) (Sept. 28, 2018) ........................................................................... 22 n.102, 30 n.143

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of NEXTERA ENERGY SEABROOK, LLC Docket No. 50-443-LA-2 (Seabrook Station, Unit 1)

NRC STAFF PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW FOR THE ADMITTED CONTENTION (Representativeness of the Large-Scale Test Program Data to the Progression of Alkali-Silica Reaction at Seabrook)

I. INTRODUCTION 1.1 The Atomic Safety and Licensing Boards initial decision rules on all outstanding issues associated with the NextEra Energy Seabrook, LLC, license amendment request (LAR) to adopt a methodology to account for the impacts of alkali-silica reaction (ASR) (also known as alkali-aggregate reaction (AAR)) on seismic Category I 1 reinforced concrete structures at Seabrook Station, Unit No. 1. 2 Specifically, the Boards initial decision rules on whether the 1 Seismic Category I structures, systems, and components include those necessary to control the release of radioactive material or otherwise mitigate the consequences of an accident. See Exhibit NRC088 BD01, Regulatory Guide (RG) 1.29, Seismic Design Classification for Nuclear Power Plants at 5 (July 2016) (ML19205A444).

2 Exhibit INT010-00-BD01/Exhibit NRC089-00-BD01, License Amendment Request 16-03, Revise Current Licensing Basis to Adopt a Methodology for the Analysis of Seismic Category I Structures with Concrete Affected by Alkali-Silica Reaction (Aug. 1, 2016) (ML19161A381 (nonproprietary) and ML19205A478 (proprietary), respectively) (Original LAR) (The Staff does not cite Exhibit INT011-00-BD01 because it includes highlighting that is not a part of the original document).

NextEra supplemented the Original LAR on September 30, 2016, October 17, 2017, December 11, 2017, and June 7, 2018. Exhibit NRC010-00-BD01, Letter from Ralph A. Dodds III, NextEra, to NRC, Seabrook Station, Supplement to License Amendment Request 16-03, Revise Current Licensing Basis to Adopt a Methodology for the Analysis of Seismic Category I Structures with Concrete Affected by Alkali-Silica Reaction (Sept. 30, 2016) (ML19205A356) (Sept. 2016 LAR Supplement); Exhibit NRC013-00-BD01, Letter from Eric McCartney, NextEra, to NRC, Seabrook Station, Response to Request for

large-scale test program (LSTP), undertaken for NextEra at the Ferguson Structural Engineering Laboratory (FSEL), has yielded data that are representative of the progression of ASR at Seabrook and that, as a result, the proposed monitoring, acceptance criteria, and inspection intervals of the ASR expansion monitoring program proposed in the LAR are adequate. ASR is a chemical reaction in concrete that occurs in the presence of moisture where alkalis, usually from the cement, react with certain reactive types of silica in the aggregate, which produces an alkali-silica gel that can absorb water and expand to cause micro-cracking of the concrete. 3 Excessive expansion of the gel can lead to significant cracking that may degrade the material properties of the concrete. 4 The purpose of the LSTP was to determine whether the structural properties of the Seabrook reinforced concrete structures could still be conservatively estimated by the existing Seabrook design basis codes, even Additional Information Regarding License Amendment Request 16-03 Related to Alkali-Silica Reaction (Oct. 3, 2017) (ML19205A358) (Oct. 2017 LAR Supplement); Exhibit NRC014-00-BD01, Letter from Eric McCartney, NextEra, to NRC, Seabrook Station, Response to Request for Additional Information Regarding License Amendment Request Related to Alkali-Silica Reaction (Dec. 11, 2017)

(ML19205A359) (Dec. 2017 LAR Supplement); Exhibit NRC015-00-BD01, Letter from Christopher Domingos, NextEra, to NRC, Seabrook Station, Response to Request for Additional Information Regarding License Amendment Request 16-03 (June 7, 2018) (ML19205A360) (June 2018 LAR Supplement) (enclosure 3 of this submittal is Exhibit INT023-00-BD01 and enclosure 4 is Exhibit INT024-00-BD01). Separately, on May 18, 2018, in updating its license renewal application for Seabrook, NextEra provided revised versions of MPR Associates (MPR) reports previously submitted as LAR supplements. Exhibit NRC016-00-BD01, Letter from Eric McCartney, NextEra, to NRC, Seabrook Station Revised Structures Monitoring Aging Management Program (May 18, 2018) (ML19205A361)

(May 2018 MPR Reports Update) (enclosure 2 of this letter is INT017-00-BD01; enclosure 4, MPR-4153, Rev. 3 (nonproprietary) is INT018-R-00-BD01; enclosure 5, MPR-4273, Rev. 1 (non-proprietary) is INT019-R-00-BD01; enclosure 6, MPR-4153, Rev. 3 (proprietary) is INT020-00-BD01; Enclosure 7, MPR-4273, Rev. 1 (proprietary) is INT020-00-BD01).

Collectively, the Original LAR, all LAR supplements, and the May 18, 2018 MPR report revisions, including all enclosures and attachments, constitute the LAR.

3 Exhibit NRC001-R-00-BD01, Staff Testimony at 6-8 (ML19261A762); Exhibit INT024-00-BD01/Exhibit INT025-00-BD01, Safety Evaluation by the Office of Nuclear Reactor Regulation Related to Amendment No. 159 to Facility Operating License No. NPF-86, encl. 2 at 5 (Mar. 11, 2019) (ML19161A392 (nonproprietary) and ML19162A020 (proprietary), respectively) (Safety Evaluation (SE)); Exhibit NRC060-00-BD01, NRC Information Notice 2011-20: Concrete Degradation by Alkali-Silica Reaction, at 2 (Nov.

18, 2011) (ML19205A432) (IN-2011-20).

4 Exhibit NRC001-R-00-BD01, Staff Testimony at 6-8. The material properties of concrete include compressive strength, elastic modulus, tensile strength, shear strength, and flexural strength. Id. at 7.

though the material properties of the Seabrook concrete affected by ASR may be degraded. 5 In general, the LSTP data demonstrated that as long as ASR expansion within Seabrook structures remains below the limits established from the LSTP, the structural properties will be unaffected. Therefore, the structural performance of the structures can still be conservatively estimated by the design basis codes, regardless of degradations in concrete material properties due to ASR. 6 1.2 This ruling is in response to a request for a hearing on the LAR filed by the C-10 Research and Education Foundation (C-10) on April 10, 2017. 7 The request included ten proposed contentions. 8 In LBP-17-7, the Board ruled that C-10 had demonstrated standing and had pled five admissible contentions, which the Board reformulated into the following single contention:

The large-scale test program, undertaken for NextEra at the FSEL, has yielded data that are not representative of the progression of ASR at Seabrook. As a result, the proposed monitoring, acceptance criteria, and inspection intervals are not adequate. 9 From September 24-27, 2019, the Board held an evidentiary hearing on the reformulated contention at the Newburyport City Hall Auditorium.

1.3 C-10s position in this proceeding is that the LSTP was not representative of the concrete structures at Seabrook and that, therefore, NextEra has not met its burden of demonstrating by a preponderance of the evidence that its proposed monitoring based on the 5 Exhibit NRC001-R-00-BD01, Staff Testimony at 58.

6 Id. at 8-9, 58.

7 C-10 Research and Education Foundation, Inc. Petition for Leave to Intervene: Nuclear Regulatory Commission Docket No. 50-443 at 2-3 (Apr. 10, 2017) (ML17100B013).

8 Id.

9 NextEra Energy Seabrook, LLC (Seabrook Station, Unit 1), LBP-17-7, 86 NRC 59, 114 (2017).

data from the LSTP is adequate to assess the progression of ASR at Seabrook. 10 Among other things, C-10 argued that NextEras approach of using the LSTP data to demonstrate the continuing applicability of Seabrooks design basis codes to its concrete structures, despite the presence of ASR, fails to address the complexities of ASR. 11 C-10s position is supported by the testimony of its expert witness Victor E. Saouma. 12 1.4 NextEras position in this proceeding is that the preponderance of the evidence demonstrates that NextEras approach of using the existing design basis codes within the limits of the LSTP is based on sound science and well-established principles of practical structural engineering, is fully compliant with all applicable codes and regulations, and is based on the long-established licensing and design basis for Seabrook. 13 NextEras position is supported by the testimony of its expert witnesses from MPR Associates, Inc. (MPR): Michael Collins, John Simons, Christopher Bagley, Oguzhan Bayrak, and Edward Carley. 14 NextEras position is also supported by the testimony of its expert witnesses from Simpson Gumpertz & Heger Inc. (SGH):

Said Bolourchi, Glenn Bell, and Matthew Sherman. 15 10 Memorandum (Distributing Redacted Transcript) at 235-36 (Sept. 24-27, 2019) (ML19312B609) (Tr.).

11 Id. at 236.

12 See C-10 Research and Education Foundation, Inc. In[i]tial Statement of Position on C-10s Contentions Regarding NextEras Program for Managing ASR at Seabrook Station Nuclear Power Plant at 1 (Jun. 10, 2019) (ML19161A371); Exhibit INT001-R, Pre-filed Testimony of Victor E. Saouma, Ph.D Regarding Scientific Evaluation of NextEra's Aging Management Program for ASR at the Seabrook Nuclear Power Plant - Corrected June 20, 2019 at 1-5 (ML19171A403) (Non-publicly available).

13 Tr. at 238-39.

14 NextEra Energy Seabrook LLCs Statement of Position at 1 (Jul. 24, 2019) (ML19205A488); Exhibit NER001-00-BD01, Testimony of NextEra Witnesses Michael Collins, John Simons, Christopher Bagley, Oguzhan Bayrak, and Edward Carley (MPR Testimony) at 1-13 (ML19205A489).

15 See NextEra Energy Seabrook LLCs Statement of Position at 1; Exhibit NER004-00-BD01, Testimony of NextEra Witnesses Said Bolourchi, Glenn Bell, and Matthew Sherman (SGH Testimony) at 1-78 (ML19205A501).

1.5 The Staffs position in this proceeding is (1) that the discovery of ASR at Seabrook challenged the plants licensing basis, (2) that NextEra developed a method to address this challenge, (3) that the Staff properly determined that NextEras method provides reasonable assurance of adequate protection of public health and safety, and (4) that C-10s arguments do not demonstrate that NextEras method is unsafe. 16 The Staff also noted that the LAR is made up of two, separate monitoring programs: the Seabrook ASR expansion monitoring program and the Seabrook structure deformation monitoring program. 17 Since the admitted contention only addressed the ASR expansion monitoring program, the Staffs position is that C-10s arguments based upon the separate structure deformation monitoring program are outside the scope of this proceeding. 18 The Staffs position is supported by the testimony of its expert witnesses: Angela Buford, Bryce Lehman, George Thomas, and Jacob Philip. 19 1.6 Based on its review of the evidentiary record in this proceeding and after full consideration of C-10s arguments, the Board finds that:

1. NextEra has demonstrated by a preponderance of the evidence that the LSTP yielded data that are representative of the progression of ASR at Seabrook.

2. NextEra has demonstrated by a preponderance of the evidence that the Seabrook ASR expansion monitoring programs monitoring, acceptance criteria, and inspection intervals derived from the LSTP are adequate.

3. The implementation of the Seabrook structure deformation monitoring program is not based on data generated by the LSTP and, therefore, the structure deformation monitoring program is not within the scope of this proceeding.

4. NextEra has demonstrated by a preponderance of the evidence that, even if the Seabrook structure deformation monitoring program were within the scope of this proceeding, its monitoring, acceptance criteria, and inspection intervals are adequate.

16 Tr. at 249-50.

17 Id. at 255-56.

18 Id.

19 See NRC Staff Initial Written Statement of Position at 1-2 (Jul. 24, 2019) (ML19205A341); Exhibit NRC001-R-00-BD01, Staff Testimony at 1-6; Exhibit NRC005-00-BD01, Exhibit NRC005-00-BD01, Jacob Philip Testimony at 2 (ML19205A348).

1.7 Based on these findings of fact and conclusions of law, the Board concludes that NextEra has carried its burden of providing, by a preponderance of the evidence, reasonable assurance that, with the approval of the LAR, Seabrook will continue to meet the applicable NRC requirements and will not endanger the health and safety of the public.

II. FINDINGS OF FACT A. The Discovery of ASR at Seabrook and NextEras Development of the Seabrook ASR Expansion Monitoring Program and the Seabrook Structure Deformation Monitoring Program 2.1 In June 2009, NextEra initially identified pattern cracking typical of ASR at Seabrook in the B electrical tunnel, and, subsequently, in several other seismic Category I structures. 20 2.2 After NextEra submitted a license renewal application for Seabrook in May 2010, 21 the Staff observed, during license renewal audit walkdowns, degradation in concrete structures exposed to groundwater, including the containment enclosure building. 22 20 Exhibit NRC001-R-00-BD01, Staff Testimony at 10; Exhibit INT024-00-BD01, SE encl. 2 at 5; see Exhibit NRC019-00-BD01, Confirmatory Action Letter, Seabrook Station, Unit 1 - Information Related to Concrete Degradation Issues, at 1 (May 16, 2012) (ML19205A364) (CAL); Exhibit NRC078-00-BD01, Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station Response to Confirmatory Action Letter, encl. 1 at 1 (unnumbered) (May 24, 2012) (ML19205A442) (NextEra Response to CAL).

21 Letter from Paul O. Freeman, Site Vice President, NextEra, to NRC, Seabrook Station Application for Renewed Operating License (May 25, 2010) (ML101590099) (LRA).

22 Exhibit NRC001-R-00-BD01, Staff Testimony at 10; Letter from Richard Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information Related to the Review of the Seabrook Station License Renewal Application (TAC No ME4028) - Aging Management Programs, encl. at 10-11, 16 (Nov. 18, 2010) (ML103090558) (Nov. 2010 RAI); Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station, Response to Request for Additional Information, NextEra Energy Seabrook License Renewal Application, Aging Management Programs, encl. 1 at 26, 32-33 (Dec. 17, 2010) (ML103540534) (Dec.

2010 Response to RAI). In its response to the Staffs Request for Additional Information (RAI), NextEra stated that it would perform confirmatory testing and evaluation of the containment enclosure building to determine whether the observed concrete degradation was due to ASR. Dec. 2010 Response to RAI, encl. at 31-33. NextEra subsequently confirmed the presence of ASR in the containment enclosure building. Exhibit NRC079-00-BD01, Enclosure 2 to SBK-L-12106, The Evaluation, Impact of ASR on Concrete Structures and Attachments, § 3.1.2 at 20 (May 2012) (ML19205A445) (Interim Structural Assessment).

2.3 In August 2010, NextEra confirmed the presence of ASR in concrete in the below-grade walls of several Seabrook structures through petrographic analysis of concrete cores removed from the affected plant structures. 23 In addition to the B electrical tunnel, NextEra confirmed ASR in the residual heat removal (RHR) and containment spray (CS) equipment vault, the emergency feedwater pumphouse, the diesel generator building, and the containment enclosure building. 24 2.4 In September 2010, NextEra initiated prompt operability determinations to assess the safety significance of the ASR issue and the basis for continued plant operation. 25 NextEra concluded that although the ASR-affected structures did not conform to Seabrooks licensing basis (because ASR was not accounted for in the licensing basis), the structures were still operablethey would maintain structural integrity for design basis loads and load combinations under normal, accident, and environmental extreme conditions. 26 As NextEra collected more The Seabrook containment enclosure building is a reinforced concrete right cylindrical structure with a hemispherical dome. The inside diameter of the cylinder is 158 feet. The vertical wall varies in thickness from 36 inches to 15 inches; the dome is 15 inches thick. The inside of the dome is 5-6 above the top of the containment dome. Exhibit NRC007-00-BD01, Seabrook Station Updated Final Safety Analysis Report, Chapter 3, Design of Structures, Components, Equipment and Systems, Rev. 18, § 3.8.4.1 (October 2017) (ML19205A350) (UFSAR). Inside the containment enclosure building is the Seabrook containment, which is a reinforced concrete system with a leaktight steel liner attached to the inside surface designed to safely withstand the load combinations and to provide biological shielding for normal and accident conditions. Exhibit NRC007-00-BD01, UFSAR § 3.8.1.4. It is the primary containment for containing radioactive release. Tr. at 858-59. The containment enclosure building and the containment are separated by a four feet six annulus between the outside of the containment building and the inside of the containment enclosure building. Id. at 859.

23 Exhibit INT024-00-BD01, SE encl. 2 at 5; Exhibit INT010-00-BD01, Original LAR at 8 of 73 (unnumbered).

24 See Exhibit NRC079-00-BD01, Interim Structural Assessment, § 3.1.1 at 19-20 (stating that petrographic examination confirmed the presence of ASR in the B electrical tunnel, the RHR & CS equipment vault, the emergency feedwater pumphouse, the diesel generator building, and the containment enclosure building).

25 Exhibit NRC025-00-BD01, Letter from Christopher G. Miller, NRC, to Kevin Walsh, NextEra, Seabrook Station, Unit No. 1 - Confirmatory Action Letter Follow-up Inspection - NRC Inspection Report 05000443/2012009, Enclosure, Inspection Report No. 0500044312012009, at 1 (Dec. 3, 2012)

(ML19205A373.14) (2012 CAL Follow-up Inspection).

26 Id., encl. at 4; Exhibit INT024-00-BD01, SE, encl. 2 at 6.

information on the presence of ASR at Seabrook and applied revised analytical techniques, it revised the prompt operability determinations. 27 2.5 In October 2010, the Staff conducted a nine-day onsite audit of NextEras aging management programs in connection with the license renewal application. 28 The audit report noted that the Staff had found that groundwater migrated into the annular space between the concrete enclosure building and concrete containment and that [t]he bottom 6 feet of the concrete containment wall was in contact with the groundwater for a long period of time. 29 After noting that ASR-related cracking had been observed in concrete structures at Seabrook, including the containment enclosure building, the audit report stated that the Staff needed further information to evaluate the impact of ASR on the Seabrook aging management programs. 30 2.6 Between November 2010 and June 2011, the Staff sent NextEra several RAIs regarding NextEras license renewal application and, specifically, for further information on ASR at Seabrook. 31 27 Exhibit NRC001-R-00-BD01, Staff Testimony at 10; Exhibit NRC025-00-BD01, 2012 CAL Follow-up Inspection, encl. at 1; see Exhibit NRC033-00-BD01, Letter from Mel Gray, NRC, to Dean Curtland, NextEra, Seabrook Station, Seabrook Station - Inspection Report 05000443/2016008 Related to Alkali-Silica Reaction Affects on Safety-Related Concrete Structures and Notice of Violation, encl. 2 at 1-2 (May 6, 2016) (ML19205A398) (May 2016 Inspection Report).

28 Exhibit NRC020-00-BD01, Letter from Richard A. Plasse, NRC, to Paul Freeman, NextEra, Audit Report Regarding the Seabrook Station License Renewal Application (TAC Number ME4028), encl. at 1 (Mar. 21, 2011) (ML19205A365) (Mar. 2011 Audit Report).

29 Id. encl. at 65.

30 Id. encl. at 65-66; 74-75.

31 See, e.g., Nov. 2010 RAI, encl. at 10; Letter from Richard A. Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information Related to the Review of the Seabrook Station License Renewal Application, encl. at 2-3 (Mar. 17, 2011) (ML110350630); Letter from Richard A. Plasse, NRC, to Paul Freeman, NextEra, Request for Additional Information for the Review of the Seabrook Station License Renewal Application, encl. at 2-3, 5 (June 29, 2011) (ML11178A338).

2.7 In 2011, the Staff conducted three inspections of Seabrook that included a review of NextEras prompt operability determinations related to ASR-affected structures. 32 2.8 In January 2012, the Staff completed an inspection to assess NextEras progress in developing a corrective plan and schedule to address the ASR degradation issue. 33 This inspection included a review by NRC regional inspectors and headquarters experts of NextEras prompt operability determinations. 34 After this inspection, the Staff found that (1) NextEra used conservative load factors to ensure that there was sufficient engineering margin, (2) Staff field walkdowns confirmed no significant indications of deformation, distortion, or rebar corrosion, and (3) ASR was localized and occurring slowly based on existing operating experience. 35 Therefore, the Staff concluded that, although Seabrook was not meeting its licensing basis because ASR was not accounted for in the licensing basis, its ASR-affected structures remained capable of performing their safety functions. 36 32 Exhibit NRC001-R-00-BD01, Staff Testimony at 10-11; Exhibit NRC021-00-BD01, Letter from Arthur L.

Burritt, NRC, to Paul Freeman, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2011002 (May 12, 2011) (ML19205A369) (May 2011 Inspection Report); Exhibit NRC022-00-BD01, Letter from Richard J. Conte, NRC, to Paul Freeman, NextEra, NextEra Energy Seabrook - NRC License Renewal Inspection Report 05000443/2011007 (May 23, 2011)

(ML19205A370); Exhibit NRC023-00-BD01, Letter from Arthur L. Burritt, NRC, to Paul Freeman, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2011003 (Aug. 12, 2011)

(ML19205A372) (Aug. 2011 Inspection Report).

33 Exhibit NRC001-R-00-BD01, Staff Testimony at 11; Exhibit NRC024-00-BD01, Letter from Christopher G. Miller, NRC, to Paul Freeman, NextEra, Seabrook Station - NRC Inspection Report 05000443/2011010 Related to Alkali-Silica Reaction Issue in Safety Related Structures, at 1 (Mar. 26, 2012) (ML19205A373) (Mar. 2012 Inspection Report).

34 Exhibit NRC001-R-00-BD01, Staff Testimony at 11; Exhibit NRC024-00-BD01, Mar. 2012 Inspection Report at 1.

35 Exhibit NRC001-R-00-BD01, Staff Testimony at 11; Exhibit NRC024-00-BD01, Mar. 2012 Inspection Report, encl. at 5-6.

36 Exhibit NRC001-R-00-BD01, Staff Testimony at 11.

2.9 At an April 2012 public meeting with NextEra, the Staff discussed its concerns for the long-term operability of the ASR-affected structures at Seabrook. 37 Subsequently, by letters dated May 3 and 10, 2012, NextEra described the actions that it would take to address the degraded conditions. 38 The Staffs concerns contributed, in part, to NextEras development of the ASR expansion monitoring program, which it first submitted as a supplement to its license renewal application on May 16, 2012. 39 2.10 On May 16, 2012, the Staff issued a confirmatory action letter (CAL) to NextEra to confirm the licensees commitments with respect to planned actions to evaluate ASR-affected reinforced concrete structures at Seabrook. 40 These commitments included (1) submitting a root-cause analysis for the occurrence of ASR at Seabrook and related corrective action, (2) revising the prompt operability determinations for some plant components, (3) completing both short-term and long-term aggregate expansion testing, and (4) establishing monitoring requirements for selected locations in areas that exhibit ASR. 41 2.11 After the issuance of the CAL, the Staff created the Seabrook ASR Issue Technical Team (SAITT) consisting of Staff members from various divisions and offices across 37 See Exhibit NRC080-00-BD01, Memorandum from John G. Lamb, NRC, to Meena Khanna, NRC, Forthcoming Meeting with NextEra Energy Seabrook, LLC (NextEra) Regarding Seabrook Station Concrete Degradation (Mar. 23, 2012) (ML19205A446).

38 Exhibit NRC081-00-BD01, Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station Actions for Resolution of Alkali Silica Reaction (ASR) Issues (May 3, 2012) (ML19205A447); Exhibit NRC082 BD01, Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station Actions for Resolution of Alkali Silica Reaction (ASR) Issues (May 10, 2012) (ML19205A448).

39 Compare Exhibit NRC082-00-BD01 at 3 (committing to submit a license renewal aging management program for ASR-affected structures by May 25, 2012) with Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station, NextEra Energy Seabrook License Renewal Application, Structures Monitoring Program Supplement-Alkali-Silica Reaction (ASR) Monitoring (May 16, 2012) (ML12142A323)

(augmenting the existing structures monitoring program with a plant-specific ASR expansion monitoring program).

40 Exhibit NRC001-R-00-BD01, Staff Testimony at 11; Exhibit NRC019-00-BD01, CAL at 1.

41 Exhibit NRC019-00-BD01, CAL at 2-3.

the agency; the Team coordinated the onsite inspections, in-office technical reviews, and other evaluation and assessment activities associated with NextEras resolution of the Seabrook ASR issue. 42 2.12 In a May 24, 2012 letter responding to the CAL, NextEra submitted the results of its root-cause investigation, which concluded that the original concrete mixture designs at Seabrook used a coarse aggregate that was susceptible to ASR. 43 This coarse aggregate used in the concrete mixtures, in combination with groundwater intrusion or other moisture sources during the life of the plant, resulted in the observed ASR in several structures at Seabrook. 44 NextEra also submitted the results of an interim structural assessment, which evaluated the structural adequacy of reinforced concrete structures at Seabrook affected by ASR and system/component anchorages in ASR-affected concrete. 45 The assessment concluded that while the reinforced concrete structures at Seabrook remained suitable for continued service for an interim period, additional actions were required. 46 These additional actions included the proposed LSTP and periodic monitoring of the affected structures at Seabrook. 47 2.13 In September 2012, the Staff requested approval from the NRCs Executive Director for Operations (EDO) to deviate from the reactor oversight process (ROP) to increase NRC oversight of Seabrook, partly to review NextEras compliance with the 2012 CAL (2012 42 Exhibit NRC045-00-BD01, Memorandum from Eric J. Leeds, NRR, and William M. Dean, Region 1, Seabrook Alkali-Silica Reaction Issue Technical Team Charter (July 9, 2012) (ML19205A393).

43 Exhibit NRC078-00-BD01, NextEra Response to CAL, encl. 1 at 3 (unnumbered); see Exhibit INT024-00-BD01, SE, encl. 2 at 5; Exhibit INT010-00-BD01, Original LAR at 8 of 73 (unnumbered).

44 Exhibit NRC078-00-BD01, NextEra Response to CAL, encl. 1 at 3 (unnumbered).

45 Exhibit NRC079-00-BD01, Interim Structural Assessment.

46 Id. at 4-5, 73.

47 Id. at 4-5, 12-13.

Deviation Memo). 48 This increased oversight would allow the Staff to more thoroughly understand the ASR phenomenon and to confirm that ASR-affected structures at Seabrook continue to perform their safety functions. 49 The Staff planned to use this increased oversight of Seabrook to (1) inspect NextEras completed and planned actions associated with the CAL commitments, (2) evaluate the quality and applicability of results from the licensees proposed LSTP, (3) provide support for the potential development of technical guidance, and (4) continue to support communications and outreach activities for stakeholders. 50 2.14 After the EDO approved the deviation from the ROP, the Staff conducted two CAL follow-up inspections to evaluate NextEras compliance with the commitments in the CAL. 51 The first inspection in the fall of 2012 involved three weeks of onsite inspection and four months of in-office review by NRC region-based inspectors and headquarters reviewers to assess the adequacy of actions taken by NextEra to address the occurrence of ASR in reinforced concrete structures at Seabrook. 52 Additionally, for this inspection, the Staffs review was informed by a separate, independent review by Dr. Kent Harries, Associate Professor of Structural Engineering and Mechanics, University of Pittsburgh. 53 In June 2013, the Staff completed the second CAL follow-up inspection, in which the Staff verified that NextEra had 48 Exhibit NRC083-00-BD01, Memorandum from William M. Dean, NRC, to R.W. Borchardt, NRC, Request for Deviation from the Reactor Oversight Process Action Matrix to Provide Increased Oversight of the Alkali-Silica Reaction Issue at Seabrook (Sept. 5, 2012) (ML19205A449) (2012 Deviation Memo).

49 Id. at 2.

50 Id.

51 See Exhibit NRC084-00-BD01, Letter from Darrell J. Roberts, NRC, to Kevin Walsh, NextEra, Deviation from the Reactor Oversight Process Action Matrix for Seabrook Station, Unit No. 1 (Sept. 12, 2012) (ML19205A450).

52 Exhibit NRC025-00-BD01, 2012 CAL Follow-up Inspection, encl. 1 at 1.

53 Id. encl. 1 at i; Tr. at 801-03.

appropriately assessed and determined that all ASR-affected structures remained operable. 54 The inspection team also confirmed that NextEras root-cause evaluation was thorough and identified appropriate corrective actions. 55 During both inspections, the Staff reviewed selected procedures and records, observed ASR crack indexing measurements, conducted independent walk-through inspections to evaluate ASR-affected structures, and interviewed Seabrook personnel regarding the adequacy of NextEras actions to address the impact of ASR on reinforced concrete structures. 56 2.15 In October 2013, after the completion of the two CAL follow-up inspections, the Staff issued a CAL closure letter, stating that the Staff had verified that NextEra had satisfied the commitments contained in the 2012 CAL. 57 The CAL closure letter noted NextEras planned LSTP testing and NextEras continuing commitment to update its operability determinations for ASR-affected structures as additional information from the testing became available. 58 The CAL closure letter also stressed that the Staff was in the process of conducting a separate review of the ASR issue as part of its review of the license renewal application. 59 Separately, the Staff informed NextEra that the exit criteria in the 2012 Deviation Memo had been met and that 54 Exhibit NRC026-00-BD01, Letter from Raymond K. Lorson, NRC, to Kevin Walsh, Seabrook Station, Unit No. 1 - Confirmatory Action Letter Follow-up Inspection - NRC Inspection Report 05000443/2012010, at 1 (Aug. 9, 2013) (ML19205A375) (2013 CAL Follow-up Inspection).

55 Id.

56 Exhibit NRC025-00-BD01, 2012 CAL Follow-up Inspection, encl. 1 at 11-12; Exhibit NRC026-00-BD01, 2013 CAL Follow-up Inspection, encl. 1 at 13-17.

57 Exhibit NRC085-00-BD01, Letter from William M. Dean, NRC, Kevin Walsh, NextEra, Closure of Confirmatory Action Letter 1-12-002, Seabrook Station, Unit 1 (Oct. 9, 2013) (ML19205A451).

58 Id. at 2.

59 Id.

inspection oversight of Seabrook would return to the ROP baseline inspection program. 60 Nonetheless, the Staff made clear that it would continue to provide focused oversight of the testing being conducted for the LSTP and NextEras continuing assessment of ASR progression in reinforced concrete structures. 61 2.16 From November 18-20, 2013, the Staff conducted an audit of NextEras initial program for monitoring ASR at Seabrook. 62 During its audit, the Staff examined the program and its bases documents, interviewed NextEra representatives, and conducted walkdowns of selected ASR-affected structures. 63 The audit concluded, among other things, that the Staff needed additional information before it could determine whether Seabrooks operating experience supported the sufficiency of the program. 64 2.17 NextEra commissioned MPR Associates (MPR) to conduct the LSTP, in collaboration with the FSEL at the University of Texas at Austin, from late 2013 to February 2016. 65 60 Exhibit NRC086-00-BD01, Letter from Darrell J. Roberts, NRC, to Kevin Walsh, NextEra, Mid-cycle Performance Review and Inspection Plan - Seabrook Station, Unit No. 1 (Report 05000443/2013006), at 1 (Sept. 3, 2013) (ML19205A452).

61 Id. at 2.

62 Exhibit NRC041-00-BD01, Letter from Richard Plasse, NRC, to Kevin Walsh, NextEra, Aging Management Program Audit Report Regarding the Seabrook Station License Renewal Application TAC No. ME4028) (Dec. 23, 2013) (ML19205A389).

63 Id., encl. at 1.

64 Id., encl. at 8.

65 See Exhibit NRC033-00-BD01, May 2016 Inspection Report, encl. 2 at 1 (NextEras testing of large scale ASR-affected test specimens at FSEL commenced in late 2013 and was planned to be completed under NextEras direction by February 2016.); Exhibit INT019-R-00-BD01, MPR-4273, Rev. 1, Seabrook Station - Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction (July 2016) (ML19170A332) (nonproprietary) (Enclosure 5 to Letter SBK-18072) at 5-1 (PDF p. 139) (MPR-4273, LSTP Report (Rev. 1)). Although the title to INT019-R-00-BD01 appears to indicate that the date of the exhibit is July 2016, the actual document lists March 2018 as the date.

INT019-R-00-BD01, LSTP Report (Rev. 1) at PDF p. 98.

NextEra submitted both propriety and nonproprietary versions of MPR-4273, LSTP Report, Rev. 0, as enclosures to the Original LAR. Exhibit INT010-00-BD01, Original LAR at 2; Exhibit NRC008 BD01/NRC009-00-BD01, MPR-4273, Rev. 0, Seabrook Station - Implications of Large-Scale Test

2.18 Staff oversight related to the LSTP involved about 5 weeks of direct inspection by NRC regional inspectors and headquarters structural experts at FSEL to ensure that the results were being appropriately reflected in the operability assessments and evaluations of ASR-affected structures. 66 The inspections of the LSTP, in particular, verified that NextEra and its contractors were adhering to the 10 C.F.R. Part 50, Appendix B, quality assurance requirements and to 10 C.F.R. Part 50, Appendix A, General Design Criterion 1. 67 Staff inspections of the LSTP observed, on a sampling basis, the setup of the program and the facilities, fabrication and concrete pour, and testing of the specimens. 68 During the inspections, the NRC inspectors did Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction (July 2016) (ML19205A352)

(nonproprietary) and ML19205A469 (proprietary), respectively) (MPR-4273 (Rev. 0)).

NextEra submitted Rev. 1 of MPR-4273 in the May 2018 MPR Reports Update. Exhibit NRC016 BD01, May 2018 MPR Reports Update at 2; INT019-R-00-BD01 (nonproprietary); INT021-00-BD01 (proprietary).

66 Exhibit NRC001-R-00-BD01, Staff Testimony at 11; see Exhibit NRC026-00-BD01, 2013 CAL Follow-up Inspection, encl. at 1; Exhibit NRC027-00-BD01, Letter from Glenn T. Dentel, NRC, to Kevin Walsh, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2013005 (Jan. 30, 2014) (ML19205A376) (Jan. 2014 Inspection Report); Exhibit NRC028-00-BD01, Letter from Glenn T.

Dentel, NRC, to Kevin Walsh, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014002 (May 6, 2014) (ML19205A377) (May 2014 Inspection Report); Exhibit NRC030 BD01, Letter from Glenn T. Dentel, NRC, to Dean Curtland, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014005 (Feb. 6, 2015) (ML19205A379) (Feb. 2015 Inspection Report) ((discussing audit conducted at FSEL during the week of October 26, 2015); Exhibit NRC032 BD01, Letter from Fred L. Bower, III, NRC, to Dean Curtland, NextEra, Seabrook Station, Unit No. 1 -

NRC Integrated Inspection Report 05000443/2015004 and Independent Spent Fuel Storage Installation Report No. 07200063/2015001 (Feb. 12, 2016) (ML19205A388) (Feb. 2016 Inspection Report).

67 Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Tr. at 1054 (And also in the - the testing program itself verified that all of the procedures, the corrective action process, the training of the staff involved in the testing, and also its applicability to the ACI Codes and consensus standards were up to Appendix B quality assurance.) (Ms. Buford). GDC 1 requires, in relevant part, that licensees establish and implement a quality assurance program in order to provide adequate assurance that these structures, systems, and components will satisfactorily perform their safety functions. 10 C.F.R. Part 50, App. A, Criterion 1.

68 Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Exhibit INT024-00-BD01, SE, encl. 2 at 10; Tr. at 1041-43 ([D]uring their seven visits to [FSEL, the Staff] witnessed all test activities including the extensometers. They saw them in use. And they saw the different varieties of instruments that [were]

tested.) (Mr. Simons); see Exhibit NRC026-00-BD01, 2013 CAL Follow-up Inspection, encl. at 1, 9; Exhibit NRC027-00-BD01, Jan. 2014 Inspection Report, encl. at 17-19; Exhibit NRC028-00-BD01, May 2014 Inspection Report, encl. at 19-22; Exhibit NRC030-00-BD01, Feb. 2015 Inspection Report, encl. at 23; Exhibit NRC032-00-BD01, Feb. 2016 Inspection Report, encl. at 25-28.

not identify any findings related to the LSTP and determined that appropriate quality assurance program requirements were being implemented. 69 2.19 The Staff also completed an onsite audit of the LSTP at FSEL from October 27-29, 2015. 70 During the audit, the Staff, among other things, conducted interviews with project staff, consultants, and laboratory technical experts; toured the FSEL facilities including the large-scale concrete testing laboratory and setup for application of loads and data acquisition, core and cylinder testing area, greenhouse for accelerating ASR in test specimens, and formwork for constructing the large-scale specimens; and observed material property testing (e.g., elastic modulus, compressive strength, etc.) of concrete cores removed from test specimens, along with two large-scale shear load tests to failure on the test specimens. 71 2.20 In May 2016, the Staff documented a finding and associated notice of violation related to NextEras maintenance of its prompt operability determinations for ASR-related structures at Seabrook. 72 2.21 NRC inspectors also documented very low safety significance findings associated with discrete, large horizontal cracks in an internal wall of the residual heat removal vaults, 73 cracks in the fuel storage building, 74 and seismic and fire seals in the containment enclosure building that appeared to have been degraded due to differential movement between 69 Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Exhibit INT024-00-BD01, SE, encl. 2 at 10; Tr. at 1054.

70 Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Exhibit NRC018-00-BD01, LSTP 2017 Site Audit Report, encl. at 1-2; Tr. at 1054.

71 Exhibit NRC018-00-BD01, LSTP 2017 Site Audit Report, encl. at 4.

72 Exhibit NRC033-00-BD01, May 2016 Inspection Report at 2, encl. 1 at 1-2; encl. 2 at 1.

73 Exhibit NRC001-R-00-BD01, Staff Testimony at 12; Exhibit NRC029-00-BD01, Letter from Glenn T.

Dentel, NRC, to Dean Curtland, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014003, encl. at 3, 15-16, (Aug. 5, 2014) (ML19205A378) (Aug. 2014 Inspection Report); see Exhibit NRC033-00-BD01, May 2016 Inspection Report at 1, encl. 1 at 1-2.

74 Exhibit NRC030-00-BD01, Feb. 2015 Inspection Report, encl. at 3, 8-10.

adjoining concrete buildings. 75 These findings contributed, in part, to NextEras development of the structure deformation monitoring program. 76 2.22 In August 2016, after the completion of the LSTP in February 2016, NextEra submitted to the NRC (1) the LAR and (2) an update to the license renewal application related to ASR aging management. 77 Both of these documents discussed two separate aging management programs related to ASR: (1) the ASR expansion monitoring program 78 and (2) the structure deformation monitoring program. 79 2.23 After NextEra submitted these documents, the Staff conducted several inspections to review the adequacy of NextEras monitoring of ASR-affected structures. 80 75 Exhibit NRC001-R-00-BD01, Staff Testimony at 12; Exhibit NRC031-00-BD01, Letter from Glenn T.

Dentel, NRC, to Dean Curtland, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2015002, encl. at 3, 18-23 (Aug. 5, 2015) (ML19205A387) (Aug. 2015 Inspection Report); see Exhibit NRC033-00-BD01, May 2016 Inspection Report at 1, encl. 1 at 1-2.

76 See Exhibit INT010-00-BD01, Original LAR at 1, 23-28, 30 of 73 (unnumbered); Letter from Eric McCartney, NextEra, to NRC, Seabrook Station, License Renewal Application Relating to the Alkali-Silica Reaction (ASR) Monitoring Program, encl. 4 at 33-36 (Aug. 9, 2016) (ML16224B079) (LRA Supplement) (discussing operating experience that led NextEra to augment the existing structures monitoring program with a plant-specific structure deformation monitoring program).

77 Exhibit INT010-00-BD01, Original LAR; LRA Supplement.

78 Exhibit INT010-00-BD01, Original LAR at 30-33 of 73 (unnumbered); LRA Supplement, encl. 3 at 2-4.

79 Exhibit INT010-00-BD01, Original LAR at 33-34 of 73 (unnumbered); LRA Supplement, encl. 3 at 4.

80 Exhibit NRC035-00-BD01, Letter from Fred L. Bower, III, NRC, to Eric McCartney, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2016004, encl. at 17-18 (Feb. 8, 2017)

(ML19205A400) (Feb. 2017 Inspection Report); Exhibit NRC036-00-BD01, Letter from Fred L. Bower, III, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2017002, encl. at 31-32 (Aug. 14, 2017) (ML19205A401) (Aug. 2017 Inspection Report);

Exhibit NRC037-00-BD01, Letter from Fred L. Bower, III, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2017004, encl. at 24-27 (Feb. 12, 2018)

(ML19205A402) (Feb. 2018 Inspection Report); Exhibit NRC038-00-BD01, Letter from Fred L. Bower, III, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2018001, encl. at 8-9 (May 14, 2018) (ML19205A403) (May 2018 Inspection Report); Exhibit NRC039-00-BD01, Letter from Mel Gray, III, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1

- Integrated Inspection Report 05000443/2018011, encl. at 7-9 (Aug. 10, 2018) (ML19205A404) (Aug.

2018 Inspection Report); Exhibit NRC040-00-BD01, Letter from Fred L. Bower, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2018003 (Nov. 13, 2018) (ML19205A405) (Nov. 2018 Inspection Report).

During these inspections, the Staff performed independent walkdowns of ASR-affected areas, examined crack gauges and the placement of extensometers, and reviewed reports of recently collected measurement data, including in-plane and through-thickness expansion, to verify that the structures were well within the established acceptance criteria. 81 The Staff also conducted three onsite audits of both monitoring programs at Seabrook, as documented in reports dated December 21, 2016, 82 July 26, 2017, 83 and May 21, 2018. 84 During all three onsite audits, the Staff specifically reviewed the calculations and other supporting documentation implementing the ASR expansion monitoring program and the structure deformation monitoring program. 85 Between the end of the LSTP in February 2016 and NextEras August 9, 2016 update to the license renewal application, the Staff completed an additional inspection, which included a review of operability determinations related to ASR-affected structures. Exhibit NRC034-00-BD01, Letter from Fred L. Bower, NRC, to Eric McCartney, NextEra, Seabrook Station, Unit No. 1 - Integrated Inspection Report 05000443/2016002, encl. at 18-20 (Aug. 5, 2016) (ML19205A399).

81 Exhibit NRC035-00-BD01, Feb. 2017 Inspection Report, encl. at 17-18; Exhibit NRC036-00-BD01, Aug. 2017 Inspection Report, encl. at 31-32; Exhibit NRC037-00-BD01, Feb. 2018 Inspection Report, encl. at 24-27; Exhibit NRC038-00-BD01, May 2018 Inspection Report, encl. at 8-9; Exhibit NRC040 BD01, Nov. 2018 Inspection Report, encl. at 9-10.

82 Exhibit NRC042-00-BD01, Letter from Tam Tran, NRC, to Eric McCartney, NextEra, Alkali Silica Reaction Monitoring Aging Management Program Audit Report Regarding the Seabrook Station, Unit 1, License Renewal (CAC No. ME4028) (Dec. 21, 2016) (ML19205A390).

83 Exhibit NRC043-00-BD01, Letter from Justin C. Poole, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Site Visit Report Regarding Regulatory Audit for License Amendment Request Re:

Alkali-Silica Reaction License Amendment Request and License Renewal Alkali-Silica Reaction Aging Management Program Review (CAC No. MF8260; EPID L-2016-LLA-0007), at 1, encl. at 2 (July 26, 2017) (ML19205A391) (July 2017 Site Audit Report) (stating that the Staff conducted the site visit from June 5, 2017 to June 9, 2017).

84 Exhibit NRC044-00-BD01, Letter from Justin C. Poole, NRC, to Mano Nazar, NextEra, Seabrook Station, Unit No. 1 - Site Visit Report Regarding Regulatory Audit for License Amendment Request Re:

Alkali-Silica Reaction License Amendment Request and License Renewal Alkali-Silica Reaction Aging Management Program Review (CAC No. MF8260; EPID L-2016-LLA-0007), at 1, encl. at 2 (May 21, 2018) (ML19205A392) (May 2018 Site Audit Report) (stating that the Staff conducted the site visit from March 19, 2018 to March 22, 2018).

85 Exhibit NRC018-00-BD01, LSTP 2017 Site Audit Report, encl. 1 at 1-3; Exhibit NRC043-00-BD01, July 2017 Site Audit Report encl. 1 at 2-3; Exhibit NRC044-00-BD01, May 2018 Site Audit Report encl. 1 at 3-5.

Additionally, the latter two site visits were conducted as part of a larger regulatory audit of the LAR. 86 The Staff held a public meeting with NextEra on August 24, 2017 to discuss the LAR. 87 2.24 In total, from 2010 to 2018, the Staffs oversight of NextEras response to the Seabrook ASR issue involved thousands of direct inspection hours by NRC regional inspectors and headquarters structural experts over the course of 20 inspections. 88 These 20 inspections included a total of 9 findings related to ASR, one of which resulted in a notice of violation; all 9 findings were of very low safety significance. 89 The Staff also conducted a total of four onsite audits at the Seabrook plant, 90 all four of which specifically reviewed the ASR expansion 86 Exhibit INT024-00-BD01, SE, encl. 2 at 33, 35, 39, 40-42, 56, 60-61; Exhibit NRC087-00-BD01, Email from Justin Poole, NRC, to Kenneth Browne, NextEra, Audit Plan Regarding Seabrook ASR License Amendment Review (Jan. 13, 2017) (ML19205A443); Exhibit NRC043-00-BD01, July 2017 Site Audit Report at 1; Exhibit NRC044, May 2018 Site Audit Report at 1.

87 Exhibit NRC046-00-BD01, Summary of August 24, 2017, Meeting with NextEra Energy Regarding License Amendment Request on Alkali Silica Reaction (Oct. 13, 2017) (ML19205A394).

88 Exhibit NRC001-R-00-BD01, Staff Testimony at 12-14; see Tr. at 1054 ([W]e did use some of the insights from the multiple inspections that were performed in order to come to some of our licensing conclusions.) (Ms. Buford).

89 Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Exhibit NRC021-00-BD01, May 2012 Inspection Report, encl. at 3-4, 9-10, 11-12 (two findings of very low safety significance related to ASR); Exhibit NRC023-00-BD01, August 2012 Inspection Report, encl. at 14-15 (one finding of very low safety significance related to ASR); Exhibit NRC024-00-BD01, Mar. 2012 Inspection Report, encl. at ii-iii (two findings of very low safety significance related to ASR); Exhibit NRC029-00-BD01, Aug. 2014 Inspection Report, encl. at 3 (one finding of very low safety significance that, while not initially attributed to ASR, was ultimately determined to be related to ASR); NRC031-00-BD01, Aug. 2015 Inspection Report encl. at 3-4 (two findings of very low safety significance related to ASR); Exhibit NRC033-00-BD01, May 2016 Inspection Report at 2 (one cited violation of very low safety significance related to ASR). Footnote eight of the Staff testimony incorrectly cites Exhibit NRC025 instead of Exhibit NRC024 and Exhibit NRC038 instead of Exhibit NRC031. These two typographical errors do not affect the substance of the Staffs testimonythat the 20 total inspections included a total of 9 findings related to ASR.

90 The NRC Staffs testimony mentions five site audits because it includes the three-day site audit of the LSTP at FSEL. Exhibit NRC001-R-00-BD01, Staff Testimony at 14; Exhibit NRC018-00-BD01, LSTP 2017 Site Audit Report.

monitoring program, 91 and three of which specifically reviewed the structure deformation monitoring program. 92 A list of the inspections is provided in Table 1 below.

Table 1 - Inspection Reports Exhibit No. Inspection Report Date 1 NRC021-00-BD01 Integrated Inspection May 12, 2011 Report 2 NRC022-00-BD01 License Renewal Inspection May 23, 2011 Report 05000443/2011007 3 NRC023-00-BD01 Integrated Inspection Aug. 12, 2011 Report 4 NRC024-00-BD01 Inspection Report 05000443/2011010 Mar. 26, 2012 Related to Alkali-Silica Reaction Issue In Safety Related Structures 5 NRC025-00-BD01 Confirmatory Action Letter Follow-up Dec. 3, 2012 Inspection 6 NRC026-00-BD01 Confirmatory Action Letter Follow-up Aug. 9, 2013 Inspection 7 NRC027-00-BD01 Integrated Inspection Jan. 30, 2014 Report 8 NRC028-00-BD01 Integrated Inspection May 6, 2014 Report 9 NRC029-00-BD01 Integrated Inspection Aug. 5, 2014 Report 10 NRC030-00-BD01 Integrated Inspection Feb. 6, 2015 Report 11 NRC031-00-BD01 Integrated Inspection Aug. 5, 2015 Report 12 NRC032-00-BD01 Integrated Inspection Report Feb. 12, 2016 05000443/2015004 and Independent Spent Fuel Storage Installation Report No.

13 NRC033-00-BD01 Inspection Report 05000443/2016008 May 6, 2016 Related to Alkali-Silica Reaction Affects On Safety- Related Concrete Structures And Notice Of Violation 14 NRC034-00-BD01 Integrated Inspection Aug. 5, 2016 Report 15 NRC035-00-BD01 Integrated Inspection Feb. 8, 2017 Report 91 Exhibit NRC041-00-BD01, encl. at 1-2; Exhibit NRC042-00-BD01, encl. at 2-3; Exhibit NRC043 BD01, encl. at 2-3; Exhibit NRC044-00-BD01, encl. at 3-4.

92 Exhibit NRC042-00-BD01, encl. at 2-3; Exhibit NRC043-00-BD01, encl. at 2-3; Exhibit NRC044 BD01, encl. at 3-4.

16 NRC036-00-BD01 Integrated Inspection Aug. 14, 2017 Report 17 NRC037-00-BD01 Integrated Inspection Feb. 12, 2018 Report 18 NRC038-00-BD01 Integrated Inspection May 14, 2018 Report 19 NRC039-00-BD01 Integrated Inspection Aug. 10, 2018 Report 20 NRC040-00-BD01 Integrated Inspection Nov. 13, 2018 Report 2.25 As explained above, NextEras development of the Seabrook ASR expansion monitoring and structure deformation monitoring programs was both in response to Staff oversight and subject to Staff oversight. 93 2.26 As part of its review of the LAR, the Office of Nuclear Reactor Regulation (NRR) requested an independent review on the overall adequacy of the LSTP by the separate Office of Nuclear Regulatory Research (RES); Jacob Philip performed this review. 94 Mr. Philip reviewed MPR-4153, Revision 2, 95 MPR-4273, Revision 0, 96 and MPR-4288, Revision 0, 97 concurred with NextEras LSTP approach in general, and recommended that NextEra corroborate the normalized elastic modulus-expansion curve derived from the LSTP on structures at Seabrook 93 Compare Exhibit NRC078-00-BD01, NextEra Response to CAL (committing to submit a license renewal aging management program for ASR-affected structures by May 25, 2012) with Letter from Paul O. Freeman, NextEra, to NRC, Seabrook Station, NextEra Energy Seabrook License Renewal Application, Structures Monitoring Program Supplement-Alkali-Silica Reaction (ASR) Monitoring (May 16, 2012) (ML12142A323) (augmenting the existing structures monitoring program with a plant-specific ASR expansion monitoring program); see LRA Supplement at encl. 4 at 33-36 (discussing operating experience that led NextEra to augment the existing structures monitoring program with a plant-specific structure deformation monitoring program).

94 Exhibit NRC005-00-BD01, Jacob Philip Testimony at 2; Exhibit INT024-00-BD01, SE, encl. 2 at 30-31.

95 Exhibits NRC011-00-BD01/NRC012-00-BD01, MPR-5153, ASR Monitoring Report (Rev. 2)

(nonproprietary and proprietary, respectively).

96 Exhibit NRC008-00-BD01, MPR-4273 (Rev. 0) (nonproprietary); Exhibit NRC009-00-BD01, MPR-4273 (Rev. 0) (proprietary).

97 Exhibit INT012-00-BD01, MPR-4288, Structure Deformation Report (Rev. 0) (nonproprietary); Exhibit INT014-00-BD01, MPR-4288, Rev. 0, Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design Evaluations (July 2016) (Enclosure 2 to Letter SBK-L-16071 [Original LAR]) (proprietary).

(which the Staff subsequently required as part of its license condition). 98 In addition, after reviewing MPR-4273, which describes in detail the LSTP, Mr. Philip concluded that the LSTP with the use of large specimens is appropriate, greatly minimizes uncertainties associated with scaling, and enables the licensee to apply the test results to the analysis of the ASR condition existing at Seabrook. 99 In particular, Mr. Philip noted that the sizes of the specimens used in the LSTP were of the same order as those at Seabrook and equipped with similar reinforcement. 100 The Staff incorporated Mr. Philips conclusions into the safety evaluation. 101 2.27 In September 2018, the Staff completed a draft safety evaluation (SE) for the LAR and a final Safety Evaluation Report (SER) for the Seabrook license renewal application. 102 The Staff provided these documents to the Advisory Committee on Reactor Safeguards (ACRS) to support the ACRSs review of the Staffs efforts related to closing out the license renewal open item on ASR. 103 The ACRS is independent of the Staff and reports directly to the 98 Exhibit NRC005, Jacob Philip Testimony at 3-7; Exhibit INT024, SE, encl. 2 at 30-31. RES and NRR both independently determined that NextEra must perform confirmatory corroboration studies. Tr. at 1029.

99 Exhibit INT024-00-BD01, SE, encl. 2 at 30; see Exhibit NRC005-00-BD01, Jacob Philip Testimony at 9-10.

100 Exhibit INT024-00-BD01, SE, encl. 2 at 30; see Exhibit NRC005-00-BD01, Jacob Philip Testimony at 9-10.

101 Exhibit INT024-00-BD01, SE, encl. 2 at 30.

102 Safety Evaluation Report Related to the License Renewal of Seabrook Station, Docket No. 50-443, NextEra Energy Seabrook, LLC (Sept. 28, 2018) (ML18254A294) (LRA SER).

103 Exhibit NRC047-00-BD01, Memorandum from James G. Danna, NRC, to Andrea D. Veil, ACRS, Seabrook Station, Unit No. 1 - Submission of Alkali-Silica Reaction License Amendment Request Draft Safety Evaluation to Support the Advisory Committee on Reactor Safeguards Review of Seabrook License Renewal (Sept. 28, 2018) (ML19205A395).

Commission, which appoints its members. 104 ACRS review and report is required of all license renewal applications. 105 2.28 The ACRS conducted an independent review of and reported on NextEras approach for addressing ASR at Seabrook. After reviewing the history of the ASR condition at Seabrook, including reviewing relevant documents and meeting with the Staff and NextEra, the ACRS concluded in its report that NextEra has undertaken substantial and thorough actions to identify, understand, and address this condition. 106 The ACRS determined that the two new Aging Management Programs to monitor alkali-silica reaction and building deformation assure that the effects of [ASR] will be effectively tracked and evaluated through the end of the license renewal application period of extended operation. 107 With respect to the LSTP specifically, the ACRS found that [t]he LSTP test samples were highly representative of the ASR-affected structures at Seabrook. 108 The ACRS noted that, although there were limited data available on the effects of ASR on highly constrained structures at the time of the discovery of ASR at Seabrook, since then a large body of ASR research similar to the LSTP is ongoing and that this research has produced similar results to the LSTP and has chosen a similar approach of fabricating prototypical, structural-sized test samples, with concrete produced to artificially accelerate ASR. 109 Therefore, the ACRS concluded that while some of the Seabrook 104 Atomic Energy Act of 1954, as amended, § 29, Advisory Committee on Reactor Safeguards; composition; tenure; duties; compensation (42 U.S.C. § 2039) (Nov. 10, 1998).

105 10 C.F.R. § 54.25. See also 10 C.F.R. § 50.58(a) (An application for an amendment to a construction permit or operating license may be referred to the [ACRS] for review and report. Any report shall be made part of the record of the application and available to the public.).

106 Exhibit NRC048-00-BD01, Letter from Michael Corradini, Chairman, ACRS, to Kristine L. Svinicki, Chairman, NRC, Seabrook Station Unit 1 License Renewal Application: Review of Licensee Program Addressing Alkali-Silica Reaction, at 1 (Dec. 14, 2018) (ML19205A396) (Corradini Letter).

107 Id.

108 Id. at 3 (emphasis added).

109 Id. at 4.

structures are degraded, they are fully capable of performing their credited function through the requested [period of extended operation] under the committed enhanced monitoring and evaluations. 110 The ACRS report did not make any further recommendations. 111 2.29 After reviewing the separate, independent reviews of Mr. Philip and the ACRS, on March 11, 2019, the Staff issued its final SE for the LAR. 112 2.30 In the final SE, the Staff found that the licensee developed a representative test program and that it is reasonable to apply the conclusions of the MPR/FSEL LSTP to the structures at Seabrook within the bounds and limits of the test program, regardless of the results of material property testing on ASR-affected concrete cores. 113 2.31 Recognizing that NextEras proposed ASR expansion monitoring program was a first-of-a-kind approach, the Staff included a license condition that requires NextEra to perform actions to confirm the continued applicability of the LSTP to ASR-affected structures at Seabrook. The condition directs NextEra as follows:

Conduct assessments of expansion behavior using the approach provided in Appendix B of [MPR-4273, LSTP Report], to confirm that future expansion behavior of ASR affected structures at Seabrook Station is comparable to what was observed in the

[LSTP] and to check margin for future expansion. Seabrook completed the first expansion assessment in March 2018; and will complete subsequent expansion assessments every ten years thereafter.

Corroborate the concrete modulus-expansion correlation used to calculate pre-instrument through-thickness expansion, as discussed in [MPR-4153 ASR Monitoring Report]. The corroboration will cover at least 20 percent of extensometer locations on ASR-affected structures and will use the approach 110 Id. at 5.

111 The ACRS also independently reviewed the Staffs safety evaluations for both the license renewal application and the LAR and described the Staffs review as deliberate and comprehensive, id. at 4, and provid[ing] thorough assessments and findings, id. at 2.

112 Exhibit INT024-00-BD01, SE at 1.

113 Id. at encl. 2 at 31.

provided in Appendix C of [MPR-4273, LSTP Report]. Seabrook will complete the initial study no later than 2025 and a follow-up study 10 years thereafter. 114 2.32 This condition ensures that any issues with (1) ASR expansion in Seabrook structures as compared to ASR expansion in the LSTP test specimens and (2) the concrete modulus-expansion correlation as applied to Seabrook structures will be identified, entered into the Seabrook corrective action program, and subjected to NRC oversight. 115 Thus, if there is indication that the LSTP results do not apply to Seabrook structures, then NextEra would be required to conduct prompt operability determinations to determine whether the structures remain operable or, if they do not, shut down the facility, as dictated by the facilitys technical specifications; these activities would be subject to NRC oversight. 116 2.33 The same day that the Staff issued the final SE, the Staff issued a final no significant hazards consideration determination and issued the license amendment. 117 2.34 On March 12, 2019, the Staff issued the renewed license for Seabrook. 118 B. The LAR and its Separate ASR Expansion Monitoring and Structure Deformation Monitoring Programs 2.35 The LAR contained various reports on ASR at Seabrook, including (1) MPR-4288, Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design Evaluations, which includes NextEras methodology for performing evaluations of structural adequacy on 114 Id., encl. 2 at 59-60.

115 Exhibit NRC001-R-00-BD01 at 29, 43.

116 Tr. at 719-20, 739-42, 1012-13.

117 NextEra Energy Seabrook, LLC; Seabrook Station, Unit No. 1, License amendment; issuance, 84 Fed. Reg. 9564, 9564 (Mar. 15, 2019). See 10 C.F.R. § 2.340(a)(2)(ii) (In a contested proceeding for the amendment of a[n] operating license, where the NRC has made a determination of no significant hazards consideration, the Director, Office of Nuclear Reactor Regulation, after making the requisite findings may issue the amendment before the presiding officers initial decision becomes effective.).

118 NextEra Energy Seabrook, LLC; Seabrook Station, Unit No. 1, License renewal and record of decision; issuance, 84 Fed. Reg. 9563, 9563 (Mar. 15, 2019).

ASR-affected reinforced concrete structures at Seabrook (MPR-4288, Structure Deformation Report), 119 (2) MPR-4273, Seabrook Station - Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction, which includes a detailed discussion of the LSTP (MPR-4273, LSTP Report), 120 (3) MPR-4153, Seabrook Station -

Approach for Determining Through-Thickness Expansion from Alkali-Silica Reaction, which describes the licensees methodology for its ASR expansion monitoring program (MRP-4153, ASR Monitoring Report), 121 and (4) Simpson Gumpertz & Heger, Inc. Report, Development of ASR Load Factors for Seismic Category I Structures (including Containment) at Seabrook Station, which details the licensees methodology for evaluating ASR-related loads on concrete structures at Seabrook. 122 119 Exhibit INT012-00-BD01, MPR-4288, Rev. 0, Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design Evaluations (July 2016) (Enclosure 2 to Letter SBK-L-16071 [Original LAR])

(ML19161A382) (nonproprietary) (MPR-4288, Structure Deformation Report (Rev. 0)); Exhibit INT014 BD01, MPR-4288, Rev. 0, Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design Evaluations (July 2016) (Enclosure 2 to Letter SBK-L-16071 [Original LAR]) (Proprietary)

(ML19162A017). Although the title of Exhibit INT014-00-BD01 states that it is Enclosure 2 to Letter SBK-L-16071, the Original LAR, the proprietary version of MPR-4288, Rev. 0 is enclosure 5 to the Original LAR; enclosure 2 is the nonproprietary version of MPR-4288, Rev. 0. Exhibit INT010-00-BD01, Original LAR at 2.

120 Exhibit INT019-R-00-BD01, MPR-4273, LSTP Report (Rev. 1) (nonproprietary); Exhibit INT021 BD01, MPR-4273, LSTP Report (Rev. 1) (proprietary); Exhibit NRC008-00-BD01, MPR-4273, LSTP Report, Rev. 0 (nonproprietary); Exhibit NRC009-00-BD01, MPR-4273, LSTP Report (Rev. 0)

(proprietary).

121 Exhibit INT018-R-00-BD01, MPR-4153, Rev. 3, Seabrook Station-Approach for Determining Through-Thickness Expansion from Alkali-Silica Reaction (Sept. 2017) (nonproprietary version) (Enclosure 4 to Letter SBK-18072) (ML19170A331) (MPR-4253, ASR Monitoring Report (Rev. 3)); Exhibit INT020 BD01, MPR-4153, Rev. 3, Seabrook Station-Approach for Determining Through-Thickness Expansion from Alkali-Silica Reaction (Sept. 2017) (Proprietary version) (Enclosure 6 to Letter SBK-18072)

(Proprietary) (ML19162A018); Exhibit NRC011-00-BD01, Enclosure 3 to Sept. 2016 LAR Supplement, MPR-4153, Rev. 2, Seabrook Station-Approach for Determining Through-Thickness Expansion from Alkali-Silica Reaction" (July 2016) (nonproprietary) (MPR-4153, ASR Monitoring Report (Rev. 2))

(ML19205A357); Exhibit NRC012-00-BD01, Enclosure 5 to Sept. 2016 LAR Supplement, Rev. 2, Seabrook Station - Approach for Determining Through Thickness Expansion from Alkali-Silica Reaction (July 2016) (ML19205A470) (proprietary).

122 Exhibit INT013-00-BD01, SG&H Report 160268-R-01, Rev. 0, Development of ASR Load Factors for Seismic Category I Structures (Including Containment) at Seabrook Station, Seabrook, NH (July 2016)

(Enclosure 4 to Letter SBK-L-16071 [Original LAR]) (ML19161A383).

2.36 The LAR was intended to address ASR at Seabrook because, as discussed above, the design basis codes for the affected structures did not account for the impacts of ASR. 123 Specifically, safety-related structures other than containment were designed and constructed to comply with the 1971 edition of American Concrete Institute (ACI) Standard 318, Building Code Requirements for Reinforced Concrete (ACI 318-71) and containment was designed and constructed to comply with the 1975 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section III, Division 2, Subsection CC (together, the design basis codes). 124 Neither of these codes, however, includes methods to analyze and address the effects of ASR on structural properties. Therefore, NextEra needed to either change the Seabrook licensing basis to fit the current plant conditions or make changes to the current plant conditions to fit the existing licensing basis. 125 NextEra elected to do a combination of these things through the LAR: (1) the LAR makes specific modifications and supplements to the design basis codes, and (2) the LAR establishes both an ASR expansion monitoring program (based on the LSTP) and a structure deformation monitoring program. The ASR expansion monitoring program and structure deformation monitoring program together ensure either that the conditions at Seabrook remain within the design basis codes, as modified and supplemented, or that physical changes (repairs or 123 Exhibit NRC001-R-00-BD01, Staff Testimony at 17; Exhibit INT010-00-BD01, Original LAR, at 8-9, 11 (unnumbered). At Seabrook, safety-related structures other than the containment were designed and constructed to comply with the 1971 edition of American Concrete Institute (ACI) Standard 318, Building Code Requirements for Reinforced Concrete (ACI 318-71). Exhibit INT010-00-BD01, Original LAR, at 8-9, 11. The containment was designed and constructed to comply with the 1975 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section III, Division 2, Subsection CC. Id. Neither of these codes, however, include methods to analyze and address the effects of ASR on structural properties. Id.

124 Exhibit INT010-00-BD01, Original LAR at 8-9, 11 (unnumbered).

125 Exhibit NRC001-R-00-BD01, Staff Testimony at 43.

modifications) are made or additional analysis is performed for cases where the amended licensing basis is not met. 126 2.37 ASR can affect a concrete structure in two primary ways. First, cracking from ASR can affect structural capacity, that is, the load-carrying capacity for critical limit states. 127 Second, cracking from ASR can affect the demand on a structure by introducing a new load. 128 The LAR proposed to address (1) the effect of ASR on structural capacity through the ASR expansion monitoring program, 129 and (2) the effect of ASR on the demand on a structure through the structure deformation monitoring program. 130

a. The ASR Expansion Monitoring Program 2.38 The ASR expansion monitoring program measures cracks in ASR-affected concrete at Seabrook, first in the in-plane direction using the crack indexing (CI) or combined crack indexing (CCI) 131 method (CI/CCI). 132 Then, when in-plane expansion reaches a specified threshold, the program measures cracks in the through-thickness direction using the readings taken from a snap-ring borehole extensometer (SRBE) combined with a calculation of the 126 Id.

127 Exhibit NRC001-R-00-BD01, Staff Testimony at 18; Exhibit INT010-00-BD01, Original LAR at 9-10 (unnumbered).

128 Exhibit NRC001-R-00-BD01, Staff Testimony at 18; Exhibit INT010-00-BD01, Original LAR at 9-10 (unnumbered).

129 Exhibit NRC001-R-00-BD01, Staff Testimony at 18; Exhibit INT010-00-BD01, Original LAR at 9-10, 31-33. (unnumbered).

130 Exhibit NRC001-R-00-BD01, Staff Testimony at 18; Exhibit INT010-00-BD01, Original LAR at 9-10, 33-34 (unnumbered).

131 The CCI is the weighted average of the Cl in the two measured in-plane directions. Exhibit INT024 BD01, SE, encl. 2 at 34.

132 Exhibit NRC001-R-00-BD01, Staff Testimony at 18; Exhibit INT010-00-BD01, Original LAR at 17 (unnumbered); Exhibit INT024-00-BD01, SE, encl. 2 at 9.

through-thickness expansion that had occurred up to the time of the SRBEs installation. 133 The purpose of this monitoring is to ensure that the in-plane, through-thickness, and volumetric (the combination of in-plane and through-thickness expansions) 134 expansions remain below ASR expansion limits for the structural limit states of shear, flexure, reinforcement anchorage, and anchors. 135 The interval for this monitoring is based on the amount of in-plane expansion, categorized into three tiers: (Tier 1) when there is no indication of pattern cracking or water ingress, the inspection frequency is as prescribed in the Seabrook routine structural monitoring program; (Tier 2) when there are areas with pattern cracking that cannot be accurately measured or in-plane expansion of 0.05%, the inspection frequency is 30 months; and (Tier 3) when there is in-plane expansion of 0.1%, the inspection frequency is 6 months. 136 2.39 Aspects of the ASR expansion monitoring program are based on LSTP data; specifically, as discussed below, the in-plane expansion at which to install SRBEs, the use of SRBEs to measure through-thickness expansion, the calculation of to-date through-thickness expansion, the expansion limits, and the monitoring intervals. 137 2.40 The use of CI/CCI as part of the ASR expansion monitoring program is not based on LSTP data. Instead, as stated by NextEra expert witness Dr. Bayrak, [it is] done on the basis of best practices recommendations pulled together by industry experts and its use is 133 Exhibit NRC001-R-00-BD01, Staff Testimony at 18-19; Exhibit INT010-00-BD01, Original LAR at 17 (unnumbered); Exhibit INT024-00-BD01, SE, encl. 2 at 21; see INT019-R-00-BD01, LSTP Report, at 5-17-5-18.

134 Volumetric expansion is the combination of in-plane and through-thickness expansions. Exhibit NRC001-R-00-BD01, Staff Testimony at 19.

135 Exhibit NRC001-R-00-BD01, Staff Testimony at 19; Exhibit INT010-00-BD01, Original LAR at 30-33 (unnumbered).

136 Exhibit NRC001-R-00-BD01, Staff Testimony at 19; Exhibit INT010-00-BD01, Original LAR at 33, tbl. 5 (unnumbered).

137 Exhibit NRC001-R-00-BD01, Staff Testimony at 43.

consistent with the guidance in the U.S. Department of Transportation, Federal Highway Administration, Report on the Diagnosis, Prognosis, and Mitigation of [ASR] in Transportation Structures (FHWA Report). 138

b. The Structure Deformation Monitoring Program 2.41 As described above, in 2015, NRC inspectors documented seismic and fire seals in the containment enclosure building that appeared to have been degraded due to differential movement between adjoining concrete buildings. 139 Both NextEra and the Staff determined that this finding was the result of an effect of ASR that is separate from the expansion effect of ASR that had been addressed by the LSTP. 140 Specifically, structural demand can be added to a structure by an internal self-straining ASR load due to restraint to ASR expansion from reinforcement, geometry, and boundary conditions causing deformation. 141 Stated another way, restraint to ASR expansion applies a self-equilibrating internal tensile force to the reinforcement and an internal compressive force to the concrete, which produces additional demand that must be resisted by the structure. 142 2.42 Because the LSTP did not address this effect of ASR, NextEra developed an additional monitoring program, called the structure deformation monitoring program, 143 and 138 Tr. at 482-83 (citing Exhibit NER013-00-BD01, U.S. Department of Transportation, Federal Highway Administration, Report on the Diagnosis, Prognosis, and Mitigation of Alkali-Silica Reaction (ASR) in Transportation Structures (FHWA-HIF-09-004) (Jan. 2010) (ML19205A491) (FHWA Report)).

139 Exhibit NRC031-00-BD01, Aug. 2015 Inspection Report, encl. at 3, 18-23; see Exhibit NRC033 BD01, May 2016 Inspection Report at 1, encl. 1 at 1-2.

140 Exhibit INT024-00-BD01, SE, encl. 2 at 32 ([I]n addition to an internal prestressing effect, ASR expansion can lead to building deformation that, when restrained, results in load and additional stresses on affected structures.).

141 Exhibit NRC001-R-00-BD01, Staff Testimony at 8.

142 Id. at 58-59.

143 The final safety evaluation report for the Seabrook license renewal application refers to this program as the Building Deformation Monitoring Program. LRA SER at 1-8.

included it as part of the LAR along with the separate ASR expansion monitoring program. 144 The structure deformation monitoring program adds the self-straining ASR load to the design basis load combinations and manages building deformation.

2.43 The structure deformation monitoring program involves a three-stage process to evaluate seismic Category I structures. 145 First, in Stage 1, NextEra screens each seismic Category I structure for susceptibility to structural deformation caused by ASR. 146 In Stage 2, NextEra performs an analytical evaluation on structures that the Stage One Screening Evaluation identifies as susceptible to deformation but do not satisfy ACI 318-71 acceptance criteria. 147 In Stage 3, NextEra performs a detailed design confirmation calculation when the Stage Two Analytical Evaluation concludes that some area of a structure does not satisfy ACI 318-71 acceptance criteria or when the structure has sufficient deformation that may impact demands computed in the original design. 148 Both Stage 2 and Stage 3 involve the use of finite element models. 149 Each analysis stage establishes threshold monitoring limits for each structure; the structures are then monitored to ensure that the threshold monitoring limits are not exceeded. 150 Structures classified as Stage 1 are monitored every 3 years, structures classified as Stage 2 are monitored every 18 months, and structures classified as Stage 3 are monitored every 6 months. 151 144 See Exhibit INT010-00-BD01, Original LAR at 24, 30, 33-34 of 74 (unnumbered).

145 Id. at 24.

146 Id.

147 Id. at 25.

148 Id.

149 Id. at 25, 33-34.

150 See Exhibit INT010-00-BD01, Original LAR at 25, 33-34.

151 Id.

2.44 The implementation of the structure deformation monitoring program is not based on LSTP data. The LSTP provides the technical basis and expansion limits for using the code-based approach and the structural capacity acceptance criteria against which the structural demands are compared for applicable limit states. The LSTP data do not influence the structural demands calculated by the structural analyses conducted as part of the structure deformation monitoring program. 152 C. The LSTP, Why It Was Needed as the Basis for the ASR Expansion Monitoring Program, and Why Large-Scale Testing is an Appropriate Approach 2.45 ASR expansion degrades the material properties of concrete. 153 The material properties of concrete include compressive strength, tensile strength, elastic modulus, shear strength, and flexural strength. The compressive strength of a material, including concrete, is its capacity to withstand loads or stresses that tend to compress and reduce its size, as opposed to tensile strength, which is its capacity to withstand loads or stresses that tend to elongate and crack or split the material. The elastic modulus is the ratio of stress (force per unit area) to strain (ratio of change in length to the original length) in the elastic range of material behavior.

The elastic range of a material is the range in which the material can be loaded and unloaded without permanent deformation, i.e., an elastic structure deforms when a load is applied and, when the load is removed, it returns to its original state. Shear strength is the ability of a material to resist a shear stress, which is created when two planes of the same object are trying to slide past one another. Flexural strength (or bending strength) is the ability of a structural member to resist a flexural load (moment), or the members ability to resist bending when loaded. 154 152 Exhibit NRC001-R-00-BD01, Staff Testimony at 21.

153 Id. at 8-9, 58.

154 Id. at 7.

2.46 ASR expansion can also affect structural properties, or a structures capability to perform its intended function, by (1) reducing structural capacity, or the ability of the structure to carry loads, and (2) adding structural demand, or adding a load to the structure. Structural capacity can be reduced by the ASR cracking and possible reductions in material properties of the concrete. Structural demand can be added to the structure by an internal self-straining ASR load due to restraint to expansion from reinforcement, geometry, and boundary conditions causing deformation. 155 2.47 With respect to the NRCs regulations, the relevant issue is the effect that a degradation mechanism may have on structural properties and not on material properties. 156 Therefore, the relevant question with respect to the LAR at issue in this proceeding is whether a reinforced concrete structure at Seabrook, as a whole, is capable of fulfilling its intended safety functions despite the presence of ASR. 157 2.48 The material properties of the concrete within a structure are expected to be considerably better than those of concrete cores that have been removed from the structure. 158 This is because ASR causes micro-cracking and when a core is removed from a structure, the in-situ confinement that was provided by the steel reinforcing bars (rebar) and the surrounding concrete (i.e., the structural context) is lost. 159 Because of the interaction between the rebar 155 Id. at 8.

156 See, e.g., 10 C.F.R. Part 50, App. A (discussing structures, systems, and components important to safety).

157 Exhibit NRC001-R-00-BD01, Staff Testimony at 8-9, 58.

158 Id. at 9; see Tr. at 282-83 ([M]echanical properties of plain concrete, meaning concrete without reinforcement, is greatly impacted by ASR. But mechanical properties of reinforced concrete can remain and do remain - there is many examples of this in the literature - unimpacted, not influenced by ASR.

The reason for that is confinement - internal confinement provided by reinforcing bars enhance the performance of that reinforced concrete element.) (Dr. Bayrak).

159 Exhibit NRC001-R-00-BD01, Staff Testimony at 9.

and the concrete and the in-situ confinement, the load-carrying behavior of ASR-affected structures is generally better than would be expected from the material properties measured on cores taken from those structures. 160 Therefore, it is important that reinforced concrete structures affected by ASR be evaluated based on the impact of ASR on structural properties, and not necessarily on material properties of extracted cores. 161 2.49 To address the effect of ASR on structural properties, and because the structural properties of ASR-affected concrete structures cannot necessarily be determined by the material properties of extracted cores, NextEra developed a testing program based on large-scale concrete beams fabricated to be representative of concrete structures at Seabrook. 162 Additionally, the use of concrete beams created specifically for the LSTP, as opposed to cores extracted from Seabrook, allowed for the control of test variables, for testing ASR levels beyond those exhibited in actual Seabrook structures, for the use of test methods consistent with the test data that were relied upon in developing the design basis codes, and for the use of nuclear commercial grade quality assurance. 163 As stated by NextEra expert witness Mr. Bagley, The data from the [LSTP] is the most representative data in the world of Seabrook Station. 164 2.50 The purpose of the LSTP was to determine whether, although concrete material properties can be degraded by ASR, the structural performance of Seabrook reinforced concrete structures could still be conservatively estimated by the design basis codes. 165 160 Id.

161 Id.

162 See Exhibit INT024-00-BD01, SE at 6-7; Exhibit NER001-00-BD01, MPR Testimony at 15.

163 Exhibit NRC001-R-00-BD01, Staff Testimony at 24-25; Tr. at 549-50.

164 Tr. at 549. NextEra also determined that it could not use literature data instead of large-scale test specimens because the available data did not discuss the specifics of the concrete involved and so NextEra was unable to determine whether these data would be representative of the concrete structures at Seabrook. Id.

165 Exhibit NRC001-R-00-BD01, Staff Testimony at 58.

2.51 The LSTP used large-scale test specimens that reflected the characteristics of ASR-affected reinforced concrete structures at Seabrook. The LSTP tested various levels of ASR cracking to assess its impact on selected structural limit states. The ACRS independently approved this approach, noting that the National Institute of Standards program (and others) chose a similar approach of fabricating prototypical, structural-sized test samples, with concrete produced to artificially accelerate ASR. 166 The Staff also determined that accelerating ASR expansion in large-scale test specimens was consistent with the literature. 167 C-10 expert witness Dr. Saouma, represented that he has cast large-scale test specimens with artificially accelerated ASR. 168 As stated by NextEra expert witness Dr. Bayrak, this is very commonly done in laboratory setting[s]. 169 2.52 In general, the LSTP data demonstrated that as long as ASR expansion within Seabrook structures remains below the limits established from the LSTP, the structural properties will be unaffected and, therefore, the structural performance of the structures can still be conservatively estimated by the design basis codes, regardless of reductions in concrete material properties due to ASR. 170 As summarized by NextEra expert witness Mr. Sherman, the whole point of this entire project, is to know where we are [with respect to ASR expansion at Seabrook], and stay inside that box thats defined by the [LSTP] that shows that were still inside that design basis. 171 166 Exhibit NRC048-00-BD01, Corradini Letter at 4; see also Tr. at 697-98, 806-07 (Mr. Philip discussing the NIST program).

167 Tr. at 1119.

168 Id. at 409-11, 882.

169 Id. at 411-12.

170 Exhibit NRC001-R-00-BD01, Staff Testimony at 8-9, 58.

171 Tr. at 331.

2.53 NextEra used the LSTP data to develop the ASR expansion monitoring program.

NextEra separately developed the structure deformation monitoring program. NextEra requested to modify the Seabrook licensing basis to incorporate these programs via the LAR (for the period of current operation) and via a supplement to the license renewal application (for the period of extended operation). 172 2.54 C-10 argued that, in taking this LSTP approach, NextEra was confusing material strength with structural strength. 173 This argument is not borne out by the LSTP. 174 The LSTP showed, consistent with existing ASR literature, that, when affected by ASR, material properties of concrete are degraded. 175 The purpose of the LSTP, however, was not to tie material strength to structural strength, but, rather, to demonstrate that although concrete material properties may be degraded, the structural performance of the reinforced concrete member can still be conservatively estimated by the design basis code equations for the ASR levels experienced in the LSTP. 176 Thus, NextEra was not confusing material strength with structural strength, it was relying on the LSTP results to demonstrate that structural strength can still be conservatively estimated by the existing Seabrook design basis codes as long as the expansion remains below the LSTP limits, regardless of reductions in material strength. 177 2.55 C-10 faulted the NRC for not obtaining peer review of the LSTP. 178 C-10 stated that peer review is a cornerstone of engineering practice and that peer reviewers must (1) be 172 Exhibit INT010-00-BD01, Original LAR; LRA Supplement.

173 Exhibit INT001-R-00-BD01 at 17.

174 Exhibit NRC001-R-00-BD01, Staff Testimony at 58.

175 Id.

176 Id.

177 Id.

178 Exhibit INT001-R-00-BD01 at 35.

sufficiently detached from the project organization (i.e., not ultimately report to the same hierarchy), (2) be familiar with the literature, and (3) have a degree of scientific expertise and rigor that is sufficient to enable them to credibly comment. 179 Such peer review is not required by the NRCs regulations. 180 Nonetheless, the Staff gathered additional information to support its review of the LSTP through mechanisms that largely meet the three elements that C-10 asserts constitute a peer review. 181 First, the ACRS, an independent, statutorily mandated committee that is separate from the Staff and reports directly to the Commission, 182 reviewed the issue. 183 The ACRS is composed of highly qualified technical experts. 184 As part of its review, the ACRS reviewed all of the relevant materials and met with and asked questions of NextEra and the Staff. 185 Second, the Staff office with the responsibility for the review of the LAR, NRR, sought an independent opinion on the validity of the LSTP approach from Mr. Philip, a technical expert otherwise uninvolved with the Staffs review from another Staff office, RES. 186 Mr. Philip reviewed the relevant documents, concurred with the LSTP approach, 187 and determined that the correlation equation derived from the LSTP was really close to the best available data that he could find in the literature. 188 179 Id 180 Exhibit NRC001-R-00-BD01, Staff Testimony at 73-74.

181 Id.

182 42 U.S.C. § 2039.

183 Exhibit NRC048-00-BD01, Corradini Letter at 1.

184 See ACRS Membership, https://www.nrc.gov/about-nrc/regulatory/advisory/acrs/membership.html (last visited Nov. 21, 2019); Tr. at 268 (discussing the relevant qualifications of ACRS members).

185 Exhibit NRC048-00-BD01, Corradini Letter at 1; see also Official Transcript of Advisory Committee on Reactor Safeguards License Renewal Subcommittee Open Session (Oct. 31, 2018) (ML18348B117).

186 Exhibit NRC005-00-BD01, Jacob Philip Testimony at 2; Exhibit INT024-00-BD01, SE, encl. 2 at 30-31.

187 Exhibit NRC005, Jacob Philip Testimony at 3-10.

188 Tr. at 1117-21.

2.56 C-10 also faulted the Staff and its independent reviewers for not having expertise on ASR. However, Staff expert witness Mr. Philip has significant experience with respect to ASR. He is an NRC Senior Geotechnical Engineer with about 50 years of diverse experience in geotechnical and foundation engineering design, construction, and research in private industry and government. 189 He has significant expertise with concrete such as the design of concrete foundations for several nuclear power plants, research development and management with respect to the design of durable concrete structures and cementitious materials for nuclear power plants and concrete nuclear waste facilities, and the corrosion of reinforced concrete in nuclear power plants, including from ASR. For the last 7 years at the NRC, Mr. Philip has developed and managed research on ASR. 190 More specifically, Mr. Philips ASR-specific experience has included his work as the NRC project manager for NRC-sponsored ASR research at the National Institute of Standards and Technology (NIST), and as a member of the Institute for Radiological Protection and Nuclear Safety, France, Observatory of the Durability of Reinforced Concrete Structures Research Technical Group, which manages the technical aspects of a 10-15-year research project on the degradation of concrete in nuclear power plant applications. 191 Mr. Philip also organized and led, with the Canadian Nuclear Safety Commission (CNSC), the Organisation for Economic Co-operation and Development/Nuclear Energy Agency/Committee on the Safety of Nuclear Installations international project Assessment of Structures Subject to Concrete Pathologies, or ASCET. 192 189 Exhibit NRC006-00-BD01, Statement of Professional Qualifications of Jacob Philip.

190 Id. at 3.

191 Id.

192 Id. ASCET is an international project, where experts from several countries presented their results on blind numerical simulations of benchmark tests conducted by the CNSC at the University of Toronto, Canada, on concrete affected by ASR. Id.

2.57 Moreover, as discussed above, the LAR proposed using the LSTP to ensure that the concrete structures at Seabrook will remain within the facilitys design basis codes, as modified and supplemented. This codes-based approach focused on the structural properties of the concrete structures at Seabrook, an area in which the Staff and the ACRS have demonstrated expertise. For instance, Staff expert witness Dr. Thomas is a structural engineer with over thirty years of diverse experience in regulatory work, industry, and research, including in the aging management of reinforced and pre-stressed concrete safety-related structures and containments at nuclear power plants; 193 Staff expert witness Ms. Buford is a structural engineer with over 15 years of diverse experience, including in regulatory oversight and licensing safety reviews of concrete degradation issues at nuclear power plants; 194 and Staff expert witness Mr.

Lehman is a civil engineer with 15 years of structural experience, more than ten of which has been in nuclear power. 195 With respect to the ACRS, its chairman, Dr. Peter Riccardella, who participated in the ACRSs questioning of NextEra and the Staff regarding the issue of ASR at Seabrook, 196 has 45 years experience working on the structural integrity of nuclear power plant components and is an authority in the application of fracture mechanics to nuclear pressure vessels and piping. 197 He has made significant contributions to the diagnosis and correction of materials degradation concerns at operating plants. 198 193 Exhibit NRC004-00-BD01 at 1.

194 Exhibit NRC002-00-BD01 at 1.

195 Exhibit NRC003-00-BD01 at 1.

196 See, e.g., Official Transcript of Advisory Committee on Reactor Safeguards License Renewal Subcommittee Open Session at 269 (Oct. 31, 2018) (ML18348B117) (Dr. Riccardella stating that NextEras approach represents a very impressive body of work).

197 ACRS Membership, https://www.nrc.gov/about-nrc/regulatory/advisory/acrs/membership.html (last visited Nov. 21, 2019).

198 Id.

2.58 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the LSTP approach, its development by NextEra and its contractors, and its review by the Staff and its independent reviewers was appropriate.

D. The LSTPs Representativeness of the Progression of ASR at Seabrook 2.59 C-10 has challenged in this proceeding the representativeness of the LSTP by arguing that (1) the test specimens should have been harvested from Seabrook Station, Unit No. 2 rather than fabricated; (2) NextEra failed to scale the test specimens to the actual Seabrook dimensions and apply to the test specimens the actual Seabrook boundary conditions; (3) the aggregates used in the concrete mixture for the test specimens were not identical to aggregates used in the concrete mixture for Seabrook; and (4) NextEra did not account for differences in the type of ASR gel in the test specimens and at Seabrook. We address each of these arguments in turn below, finding that NextEra has demonstrated by a preponderance of the evidence that the LSTP yielded data that are representative of the progression of ASR at Seabrook.

a. Board Findings on Harvesting Concrete from Seabrook Station, Unit No. 2 2.60 C-10 argued that, instead of trying to fabricate representative test specimens, the LSTP should have used segments of the concrete walls of the partially completed Seabrook Station, Unit No. 2. 199 2.61 NextEras expert witnesses testified that the use of segments of the concrete walls of Seabrook Station, Unit No. 2 would not have been representative of the walls at Seabrook Station, Unit No. 1. As NextEra expert witness Mr. Carley explained, the Unit No. 2 concrete walls were incomplete; in fact, they were only poured to about ten feet above surface, 199 Tr. at 548-51.

and, therefore, both sides of the walls have been exposed to the environment. 200 Significantly, this exposure to outside environmental conditions meant that the top of the concrete walls of Unit No. 2 and their rebar are exposed to the environment, potentially providing a moisture path through the concrete internally. 201 Moreover, NextEra expert witnesses Mr. Bagley testified that there was no way of knowing the to-date through-thickness expansion in these concrete walls. 202 Without knowing the to-date through-thickness expansion, NextEra could not correlate any ASR-related expansion in Unit No. 2 to the structures at Unit No. 1. 203 2.62 We find that NextEra has demonstrated by a preponderance of the evidence that the use of segments of the concrete walls of Seabrook Station, Unit No. 2 would not have been representative of the walls at Seabrook Station, Unit No. 1 because the Unit No. 2 concrete walls were only poured to about ten feet above surface; both sides of the walls have been exposed to the environment; the top of the concrete walls and their rebar are exposed to the environment, potentially providing a moisture path through the concrete internally; and there is no way of knowing the to-date through-thickness expansion in these concrete walls. 204

b. Board Findings on the Scaling and Boundary Conditions of the LSTP Test Specimens 2.63 C-10 argued that the LSTP was not representative because NextEra had failed to scale the test specimens to the dimensions of the Seabrook reactor. 205 2.64 C-10s argument regarding scaling is not relevant because the tests conducted in the LSTP used almost full-scale test specimens representative of a bounding reference location 200 Tr. at 551.

201 Id. at 551-52.

202 Id.

203 Id. at 552.

204 Tr. at 551-52.

205 Exhibit INT001-R-00-BD01, Staff Testimony at 11.

of a typical wall segment in a Seabrook ASR-affected seismic Category 1 structure (i.e., the B electrical tunnel). 206 The width of the specimens were the actual dimensions at the reference location and the height was that of a representative segment (or slice) of that location. 207 The specimens included two-dimensional reinforcement mats using the same reinforcement size and spacing, one along each longitudinal face, and with no shear reinforcement, as in a typical wall at Seabrook. 208 Thus the LSTP involved full-scale load tests to failure and not model tests, as asserted by C-10. 209 Additionally, because the LSTP supplements (rather than replaces) the design code, results from appropriately representative test specimens may be applied to reinforced concrete structures throughout Seabrook. 210 2.65 C-10 faulted the LSTP for having a rebar ratio in the longitudinal direction that is greater than that in the reference location for its shear test specimens. 211 NextEra expert witness Dr. Bayrak explained, however, that this was necessary in order to study shear. 212 This is because the reference location is designed to ACI 318-71 and, as such, if not modified, would always fail in flexure before failing in shear. 213 Thus, it was necessary to adjust the longitudinal reinforcement ratio so that a shear crack [would be] observed which informs what concrete contribution to shear strength is. 214 206 Exhibit NRC001-R-00-BD01, Staff Testimony at 52-53.

207 Id.

208 Id.

209 Id.

210 Id.

211 Tr. at 277.

212 Id. at 278-79.

213 Id.

214 Id.

2.66 C-10 also argued that the test specimens were not subjected to the same boundary conditions (i.e., support, restraints, and load) as at Seabrook and that, therefore, the LSTP cannot be seen as a representative model for Seabrook. 215 Dr. Bayrak, however, explained that any differences between the boundary conditions used for the LSTP and the boundary conditions at Seabrook would not reduce representativeness but, rather, would increase conservatism. Specifically, the boundary conditions at Seabrook involve external restraint boundary conditions, structural geometry, [and] how that particular cutout portion frames into the rest of the building [, which] improve[s] the behavior of that segment so that would render beam testing not only [on the] conservative side but in many examples greatly so. 216 2.67 C-10 argued that the test specimens were not representative because their reinforcement is different than that of the containment enclosure building. 217 However, the containment enclosure building is actually more reinforced than the reference location on which the test specimens are based and, therefore, the test specimens are bounding of the containment enclosure building. 218 2.68 We find that NextEra has demonstrated by a preponderance of the evidence that the test specimens large size represented the scale and structural context of structures at Seabrook and avoided uncertainties due to scaling effects associated with using smaller 215 Exhibit INT001-R-00-BD01 at 11-12; Tr. at 770 (Dr. Saouma stating that he does not consider the boundary conditions to be representative).

216 Tr. at 282-83.

217 Id. at 770 (I consider the reinforcement ratio for the [containment enclosure building is] not representative.) (Dr. Saouma); see id. at 1046-47.

218 Tr. at 279-80, 700-702, 1047.

specimens. 219 The test specimens were also designed with reinforcement ratios and configurations similar to those at Seabrook. 220 Specifically, the specimens used a two-dimensional rebar mat in the in-plane direction to simulate the rebar in the face of the typical walls at Seabrook. 221 This allowed the structural performance tests to account for the confinement effects provided by the typical Seabrook reinforcement configuration. 222 Further, the test specimens dimensions and rebar were designed so that the specimens would best represent being part of a larger structure. 223 Finally, the test methods and experimental designs used in the LSTP were consistent with the database of test data that was used to develop the relevant Seabrook design basis code equations. 224 Therefore, with respect to scaling and boundary conditions, the test specimens were representative.

c. Board Findings on the LSTPs Representativeness of the Seabrook Concrete Aggregates 2.69 The Staff determined that NextEra has demonstrated that the concrete of the test specimens reasonably reflected the properties of concrete in Seabrook structures. 225 NextEra considered 11 different concrete mixtures, and the concrete mixture selected for the LSTP was selected because it was the most representative with respect to the structural responses of the test specimens. 226 The concrete mixture design for the test specimens was based on specifications used at Seabrook (e.g., compressive strength, coarse aggregate gradation and 219 See Exhibit NRC001-R-00-BD01, Staff Testimony at 27-29; see Exhibit NRC005-00-BD01, Testimony of Jacob Philip at 8-9; Tr. at 277-79.

220 See Exhibit NRC001-R-00-BD01, Staff Testimony at 27.

221 See id.

222 See id.

223 See id.

224 See id. at 28-29.

225 Exhibit NRC001-R-00-BD01, Staff Testimony at 27-28.

226 Tr. at 411-12.

type, water-to-cement ratio, cement type, aggregate proportions, etc.) and, in part, included constituents obtained from sources similar to those used during the construction of the plant. 227 2.70 The concrete mixture design used at Seabrook included coarse aggregate (gravel) from a quarry in Maine and fine aggregate (sand) from a quarry in New Hampshire. 228 2.71 The concrete mixture design used for the LSTP test specimens included coarse aggregate of which roughly half came from a quarry in Maine, near the quarry that was used for the concrete at Seabrook, and the other half came from a quarry in New Mexico. 229 The fine aggregate for the LSTP test specimens came from a quarry in Texas. 230 The original quarry in Maine that supplied the aggregates for the concrete at Seabrook was unavailable as it was shutdown, 231 and NextEra selected the aggregates from the New Mexico and Texas quarries for their reactivity to accelerate ASR expansion in the test specimens. 232 2.72 C-10 argued that the concrete used in the LSTP test specimens was not representative of the concrete at Seabrook because the coarse aggregate and the fine aggregate used in the LSTP were not identical to those used in Seabrook and because NextEra did not state that the gravel and sand came from the same quarry as used for Seabrook. 233 227 Id.

228 Exhibit NER001-00-BD01, MPR Testimony at 34, 49.

229 Tr. at 382; see Exhibit NER001-00-BD01, MPR Testimony at 80-81; Exhibit NER026-00-BD02, MPR-3757, Rev. 4, Shear and Reinforcement Anchorage Test Specimen Technical Evaluation (May 2014)

(FP100760) at 3-8-3-9 (ML19205A527) (Non-publicly available).

230 Exhibit NER001-00-BD01, MPR Testimony at 84.

231 Id. at 136.

232 Id. at 80-85; Tr. at 288, 634-35, 637.

233 Exhibit INT001-R-00-BD01 at 10; Tr. at 287-89.

C-10 argued that this is a material failure because the behavior of concrete is so sensitive to variables and that different sources of aggregate will result in drastically different concrete. 234 2.73 NextEras expert witnesses testified that the use of identical aggregate in the LSTP test specimens was not possible and not practical. 235 First, NextEras expert witnesses explained that the use of identical coarse aggregate and fine aggregate was not possible because the quarry from which these aggregates were obtained for Seabrook is no longer operating. 236 Moreover, NextEras expert witnesses testified that [e]ven if the quarry were still open, the rock layers that are available today would likely have a different composition than what was accessible several decades ago. 237 2.74 The Staff expert witnesses also testified that it would have been impossible to recreate Seabrook concrete exactly, as Dr. Saouma advocates because [e]ven if the aggregate and sand were taken from the same source, there would be differences in the final product. 238 The Staff expert witnesses went on to explain that although no two concrete samples will ever be exactly the same due to differences in their constituents (e.g., aggregate, sand, cement, etc.), specific criteria for the concrete mixture (e.g., water-to-cement ratio, compressive strength, etc.) can be followed to create concrete that is similar enough that it can be treated as the same for design purposes. 239 234 Exhibit INT001-R-00-BD01 at 10; Tr. at 287-89.

235 Exhibit NER001-00-BD01, MPR Testimony at 136.

236 Id.

237 Id.

238 Exhibit NRC001-R-00-BD01, Staff Testimony at 51.

239 Id. (To build on Dr. Saoumas example of bread, no two loaves of bread are ever exactly the same; however, recipes can be followed to develop a particular type of bread (e.g., baguette, ciabatta, etc.).

Concrete is similar in that no two concrete samples will ever be exactly the same due to differences in the constituents (e.g., aggregate, sand, cement, etc.); however, specifications, or recipes, can be provided that, if followed, will create concrete that is similar enough that it can be treated as the same for design

2.75 Additionally, NextEra explained that the differences in the coarse aggregate and fine aggregate used in the LSTP test specimens versus those used at Seabrook do not affect the representativeness of the specimens. 240 The concrete mixture design for the LSTP test specimens included differences from the concrete mixture at Seabrook to allow for the accelerated development of ASR. 241 As NextEras expert witnesses explained, [u]se of a concrete mixture design identical to the plant would not have produced sufficient ASR progression to reach or exceed the condition of the plant in an acceptable timeframe. 242 2.76 With respect to the coarse aggregate, as indicated above, the original, specific quarry that supplied the aggregate for the concrete at Seabrook was unavailable as it was shut-down. 243 To maximize the representativeness of the test specimens, however, NextEra transported approximately half of the concrete mixture used for the specimens from a quarry in Maine near the quarry that was used for the concrete at Seabrook. 244 The other half of the coarse aggregate came from a quarry in New Mexico that is known to be reactive. 245 The more reactive coarse aggregate allowed NextEra to accelerate ASR expansion in the test specimens. 246 Even though the New Mexico coarse aggregate was more reactive, NextEra expert witness John Simons testified that SGHs petrographer still examined the coarse purposes. The LSTP used the original Seabrook recipe and ensured that each ingredient matched the original Seabrook recipe ingredient as closely as reasonably possible in developing its test specimens.).

240 Exhibit NER001-00-BD01, MPR Testimony at 80-85; Tr. at 288, 634-35, 637.

241 Exhibit NER001-00-BD01, MPR Testimony at 80-85; Tr. at 288, 634-35, 637.

242 Exhibit NER001-00-BD01, MPR Testimony at 81.

243 Id. at 82; see Exhibit NER026-00-BD01 at 3-8 (Non-publicly available).

244 Exhibit NER001-00-BD01, MPR Testimony at 80-81, 83; Tr. at 633; Exhibit NER026-00-BD01 at 3-8 (Non-publicly available).

245 Tr. at 633; see Exhibit NER001-00-BD01, MPR Testimony at 81.

246 Tr. at 634.

aggregate from New Mexico and confirmed that it was similar to the coarse aggregate used at Seabrook. 247 Moreover, NextEra explained that ACI 318-71, the code of record for Seabrook, applies to a broad range of coarse aggregates. NextEras expert witnesses explained, [t]he conservative approaches taken by code committees in assembling databases, evaluating test data, etc., make accommodation for variability in local constituent materials. It is not practical that design expressions are specific to all local constituent materials. 248 2.77 In addition, NextEra stated that the coarse aggregate from both quarries was representative of concrete at Seabrook in that (1) the coarse aggregate was crushed stone, like at Seabrook; 249 and (2) the size of the aggregate was equal to or smaller than the aggregate at Seabrook. 250 The fact that the coarse aggregate was crushed is important because crushed stone promotes aggregate interlock, which, in turn, is important to the strength of the concrete. 251 The size of the aggregate is also important because, as NextEras expert witnesses testified, [r]esearch has shown that maximum aggregate size impacts specimen shear strength. 252 Thus, by using coarse aggregate that was equal to or smaller than the 247 Id. at 633; see id. at 382 (We actually did petrography early on to support that effort to make sure that the coarse aggregate that was being used in the testing was the same mineralogical condition as the original.) (Mr. Sherman); Exhibit NER022-R-00-BD01, MPR-4262, Shear and Reinforcement Anchorage Testing of Concrete Affected by Alkali-Silica Reaction," Vol. I, Rev. 1 (July 2016) & Vol. II, Rev. 0 (Jan.

2016) (FP100994) at 4-11 (ML19266A048) (Non-publicly available).

248 Exhibit NER001-00-BD01, MPR Testimony at 84.

249 Exhibit NER001-00-BD01, MPR Testimony at 80; Tr. at 633-64, 1081-82.

250 Exhibit NER001-00-BD01, MPR Testimony at 80; Exhibit NER026-00-BD01 at 3-9 (Non-publicly available).

251 Exhibit NER001-00-BD01, MPR Testimony at 80; see Tr. at 432-433, 1006, 1081-82.

252 Exhibit NER001-00-BD01, MPR Testimony at 80.

aggregate used at Seabrook, the test specimens had slightly lower shear strength than the concrete at Seabrook, which is conservative. 253 2.78 With respect to the fine aggregate, NextEra deliberatively used the fine aggregate from Texas because of its very high reactivity. 254 NextEras expert witnesses stated that in testing various concrete mixture designs when planning the LSTP, NextEra determined that the use of nonreactive fine aggregate (like the concrete at Seabrook) would not produce substantial ASR expansion in a reasonable timeframe and therefore would not be useful for the LSTP. 255 2.79 Similarly, the Staff determined that the concrete used in the LSTP test specimens had specifications consistent with the specifications of the Seabrook concrete and used materials as similar to the original materials as reasonably possible. 256 Thus, the LSTP concrete was not drastically different from the Seabrook concrete as asserted by Dr.

Saouma. 257 Moreover, the LSTP used concrete with ASR expansion greater than that currently present at Seabrook and, therefore, the limits derived from the LSTP are conservative. 258 2.80 Further, to the extent that there are any substantive differences between the LSTP concrete and the Seabrook concrete, the Staff found that with the license condition, there is additional assurance that these differences will not affect the public health and safety. 259 If any limits in the ASR expansion monitoring program are approached, then NextEra will perform 253 See Exhibit NER001-00-BD01, MPR Testimony at 80; Exhibit NER026-00-BD01 at 3-9 (Non-publicly available).

254 Exhibit NER001-00-BD01, MPR Testimony at 84.

255 Exhibit NER001-00-BD01, MPR Testimony at 136.

256 Exhibit NRC001-R-00-BD01, Staff Testimony at 50-51.

257 Id; see Exhibit INT001-R-00-BD01 at 10.

258 Exhibit NRC001-R-00-BD01, Staff Testimony at 50-51.

259 Id.

reanalysis or remediation, as necessary. 260 NextEra also has a continuing obligation to demonstrate that its structures can perform their safety functions so that, if the Staff was ever to have reason to believe that the design basis codes, as modified and supplemented, were no longer valid, NextEra would be required to demonstrate operability or update the Seabrook licensing basis. 261 Similarly, NextEra is obligated, through its operating experience and corrective actions programs, to evaluate relevant operating experience and evaluate whether a change to its programs is needed. 262 2.81 We find that NextEra has demonstrated by a preponderance of the evidence that while the aggregates used in the concrete of the LSTP test specimens were not identical to the aggregates used in the concrete at Seabrook, they are similar enough that the concrete can be treated as the same for design purposes. 263 Importantly, the characteristics of the aggregates that had structural implications for the specimens matched the concrete at Seabrook as closely as reasonably achievable. 264 Therefore, these differences did not affect the representativeness of the LSTP data.

d. Board Findings on the LSTPs Representativeness of the ASR Gel at Seabrook 2.82 C-10 expert witness Dr. Saouma testified that different minerology in concrete can create different types of ASR gels, which, in turn, can affect the type of cracks that one has. 265 Dr. Saouma explained that the chemical composition of the ASR gel may have an 260 Tr. at 392.

261 Id. at 575.

262 Id. at 1136-37.

263 See Exhibit NRC001-R-00-BD01, Staff Testimony at 51.

264 See Exhibit NER001-00-BD01, MPR Testimony at 80-85; Tr. at 288, 634-35, 637.

265 Tr. at 984 ([T]he gel is reflective of the type of mineralogy that we have.) (Dr. Saouma).

impact on the rate at which the elastic properties and tensile strengths are affected. 266 Based on this, he concluded that the LSTP was not sufficiently representative of the concrete at Seabrook because NextEra did not consider the ASR gel type produced in the test specimens. 267 2.83 NextEra stated that the variation in ASR gel type has no bearing on the representativeness of the LSTP. As NextEra explained, when evaluating the structural performance of concrete, the important consideration is the level of expansion of the cracking as opposed to the chemical composition of the ASR gel. 268 NextEras expert witnesses testified that while different types of ASR may cause different levels of expansion, for a given level of ASR-induced expansion, similar levels of structural impacts are to be expected, regardless of the chemical composition of the ASR gel causing the expansion. 269 At the evidentiary hearing, NextEra expert witness Mr. Bagley further explained that some variation in the chemical structure of the ASR gel doesnt have an impact on the representativeness of the test program because really what we are talking about is expansion and the amount of strain that has occurred in the concrete. 270 2.84 NextEras expert witnesses also testified that industry guidelines and published research on the structural impacts of ASR do not point to differentiation based on differences in the chemical composition of ASR gel. 271 More specifically, at the evidentiary hearing, NextEra expert witness Mr. Sherman testified that the FHWA Report mentions gel 109 times and never 266 Id. at 984; see also id. at 985-86, 988.

267 Exhibit INT001-R-00-BD01 at 10-11; Tr. 981-982, 984-85.

268 Exhibit NER001-00-BD01, MPR Testimony at 82-83; Tr. at 982-986, 990-96.

269 Exhibit NER001-00-BD01, MPR Testimony at 82-83.

270 Tr. at 982-83.

271 Exhibit NER001-00-BD01, MPR Testimony at 83; see Tr. at 994-95.

differentiates between type of gel[,] [t]he U.K. Institute of Structure Engineers document never mentions the type of gel[,] [a]nd the Canadian standard document mentions gel 19 times and never differentiates between type. 272 In fact, NextEra expert witness Dr. Bayrak testified that

[t]o our knowledge, there is no data reported in the literature that would support the argument that two different types of ASR gels that have the same level of expansion would result in different structural characteristics in the concrete. 273 2.85 The Staff expert witnesses agreed with NextEra that the chemical composition of the ASR gel is not a factor important to representativeness because [t]he key is the expansion caused by the [ASR] gel as opposed to the chemical composition of the ASR gel. 274 Staff expert witness Mr. Lehman also testified that the Staff agreed with NextEra that the published research on structural impacts of ASR does not differentiate between different types of ASR gels. 275 Staff expert witness Ms. Buford also explained that ASR research from Oak Ridge National Laboratory and NIST does not differentiate between type of [ASR] gel in terms of the structural context. 276 2.86 At the evidentiary hearing, Dr. Souma admitted that the industry guidance documents discussed by all parties (e.g., the FHWA Report 277 and the Institution of Structural 272 Tr. at 994-995; see generally Exhibit NER013-00-BD01, FHWA Report; Exhibit NER012-00-BD01, The Institution of Structural Engineers, "Structural Effects of Alkali-Silica Reaction" (July 1992)

(ML19205A524) (Non-publicly available); Exhibit NRC076-00-BD01, Canadian Standards Association (CSA) A864-00, "Guide to the Evaluation and Management of Concrete Structures Affected by Alkali-Aggregate Reaction" (Feb. 2000) (Reaffirmed 2005) (ML19205A476) (Non-publicly available).

273 Tr. at 985.

274 Id. at 986.

275 Id. at 994.

276 Id. at 996.

277 Exhibit NER013-00-BD01, FHWA Report.

Engineers report, Structural effects of [ASR] (ISE Report) 278) do not differentiate based on differences in the chemical composition of the ASR gel. 279 Instead, Dr. Saouma postulated that

[w]e need to open our minds and look through a variety of documents, and then make an assessment as whether or not the gel has a role or not. 280 2.87 We find that NextEra has demonstrated by a preponderance of the evidence that that the type of ASR gel is not relevant to the issue of the representativeness of the LSTP specimens because the cracking caused by the gel, as opposed to the chemical composition of the gel itself, is what drives ASRs impact on the structural performance of a concrete structure.

On this point, we note that Dr. Saouma provided no support for his assertion that NextEra must account for possible differences in chemical composition of the ASR-gel beyond his bare assertion that the parties need to open our minds to make an assessment as whether or not the gel has a role or not. 281 E. The Representativeness of the LSTPs Program Elements 2.88 The LSTP consisted of three key test program elements to evaluate the impact of ASR on (1) the shear capacity of reinforced concrete (the Shear Test Program), (2) the performance of expansion and undercut anchors installed in concrete (the Anchor Test Program), and (3) the reinforcement anchorage of rebar lap splices and flexural strength and stiffness (the Reinforcement Anchorage Test Program). 282 NextEra selected these three elements based on the 2012 interim structural assessment for Seabrook structures. The interim 278 Exhibit NER012-00-BD01.

279 Tr. at 988.

280 Id.

281 Id.

282 Exhibit NRC001-R-00-BD01, Staff Testimony at 23-24; Exhibit INT024-00-BD01, SE, encl. 2 at 7; Exhibit INT010-00-BD01, Original LAR at 16 of 74 (unnumbered); Exhibit INT019-R at 1-2-1-3 (PDF pp.

111-112).

assessment identified these limit states as areas where gaps existed in available literature or where available margins in Seabrook structures were low. 283 A fourth test program (the Instrumentation Test Program) evaluated instruments for monitoring through-thickness expansion in Seabrook reinforced concrete structures. 284 By his own admission, C-10 expert witness Dr. Saouma focused only on the Shear Test Program. 285

a. Board Findings on the Representativeness of the Shear Test Program 2.89 We find that NextEra has demonstrated by a preponderance of the evidence that the Shear Test Program was representative of ASR-affected reinforced concrete structures at Seabrook for four reasons. First, the program used representative control and test specimens for differing levels of ASR. 286 Second, it used a large number of load tests to failure that were consistent with the applicable Seabrook design basis code. 287 Third, it had test results that were all bounded by the strength calculated based on the ACI code provisions. 288 Fourth, the test results were consistent and repeatable. 289 Additionally, the Shear Test Programs results were similar to those reported in a recently published journal article. 290 Finally, the quantity of 283 Exhibit NRC001-R-00-BD01, Staff Testimony at 23-24; Exhibit INT024-00-BD01, SE, encl. 2 at 7; Exhibit INT019-R-00-BD01, LSTP Report at 1-2-1-3 (PDF pp. 111-112).

284 Exhibit NRC001-R-00-BD01, Staff Testimony at 23-24; Exhibit INT024-00-BD01, SE, encl. 2 at 7; Exhibit INT019-R-00-BD01, LSTP Report at 1-2-1-3 (PDF pp.111-112).

285 Tr. at 264-65 (In response to Judge Mtingwas question that [y]ou seem to concentrate strictly on the shear, Dr. Saouma responded [c]orrect.).

286 See Exhibit NRC001-R-00-BD01, Staff Testimony at 31-32.

287 See id.

288 See id.

289 See id.

290 See id.; see also Exhibit NRC056-00-BD01, Madhu M. Karthik, et. al., Experimental Behavior of Large Reinforced Concrete Specimen with Heavy ASR and DEF [delayed ettringite formation] Deterioration, J.

Struct. Eng. (2018) (published online May 31, 2018) (ML19205A484) (Non-publicly available).

the reinforcement was adjusted to preclude flexural failure, which allowed for observation of the concrete contribution to shear strength. 291 2.90 C-10 argued that, with respect to the Shear Test Program, if the program had been properly performed, cracking would have occurred in a zone without reinforcement. 292 According to Dr. Saouma, however, the load-displacement curve in MPR-4273, Rev. 1, Figure 5-5 293 is not indicative of a shear failure with minimum or no reinforcement and, therefore, some shear reinforcement must have been present. 294 Specifically, pointing to Figure 5 in his initial pre-filed written testimony, Dr. Saouma argued that what likely happened was a crack in a zone of the beam with shear reinforcement. 295 2.91 Dr. Saoumas Figure 5, however, is an inaccurate depiction of the Shear Test Program because in the program, unlike in the figure, the left support of the beam was located to the right of the end area with stirrups and, therefore, contrary to Dr. Saoumas assertion, the programs test span did not include any shear stirrups. 296 ACI 318-71 determines shear capacity (strength) based on the onset of diagonal (tension) or inclined cracking, 297 which occurred in the Shear Test Programs specimens at the blip[s], as Dr. Saouma called them, 298 291 Tr. at 278-79.

292 Exhibit INT001-R-00-BD01 at 13.

293 Exhibit INT021-00-BD01, MPR-4273, LSTP Report (Rev. 1), fig. 5-5 at 5-7 (Non-publicly available).

294 Exhibit INT001-R-00-BD01 at 13-14.

295 Id. at 14.

296 Exhibit NRC001-R-00-BD01, Staff Testimony at 55-56.

297 Exhibit NRC049-00-BD01, American Concrete Institute (ACI) Standard 318-71, Building Code Requirements for Reinforced Concrete §§ 11.4.1, 11.4.2, 11.2.3, 11.2.4 (1971) (ML19205A479) (Non-publicly available) (ACI 318-71).

298 Exhibit INT-001-R-00-BD01 at 14.

in Figure 5-5 of MPR-4273. 299 Accordingly, these points were determined to be the shear capacity. The fact that the curve proceeds, as Dr. Saouma stated, 300 is not unexpected. On the contrary, the fact that a new shear carrying mechanism, which is capable of sustaining further load, can develop in a reinforced concrete beam without shear reinforcement after the formation of diagonal cracks is well known in the literature. 301 2.92 C-10 also argued that the unanticipated crack shown in MPR-4273, Rev. 1, Figure 4-2 302 should be of the utmost concern as it jeopardizes the representativeness of the ensuing test and would cause the results to be unreliable. 303 As discussed below, NextEra confirmed that this crack was an edge effect crack that penetrated only a few inches into the specimen. 304 This crack did not compromise the representativeness of the test region because away from the edges, expansion was of about the same magnitude as the edge effect crack but distributed into finer cracks across the specimen cross sections. 305

b. Board Findings on the Representativeness of the Anchor Test Program 2.93 We find that NextEra has demonstrated by a preponderance of the evidence that the Anchor Test Program was representative of ASR-affected reinforced concrete structures at Seabrook for three reasons. First, the program was performed consistent with the Seabrook 299 Exhibit INT021-00-BD-01, MPR-4273, LSTP Report (Rev. 1), fig. 5-5 at 5-7 (Non-publicly available).

300 Exhibit INT-001-R-00-BD01 at 14.

301 Exhibit NRC001-R-00-BD01, Staff Testimony at 55-56; see Exhibit NRC072-R-00-BD01, R. Park and T. Paulay, Reinforced Concrete Structures, at 276 (John Wiley & Sons, Inc. 1975) (ML19261B304)

(Non-publicly available); Exhibit NRC073-00-BD01, David Darwin, Charles W. Dolan, and Arthur H.

Nilson, Design of Concrete Structures at 138-141 (McGraw Hill, Inc., 15th Ed. 2016) (ML19205A474)

(Non-publicly available).

302 Exhibit INT021-00-BD01, MPR-4273, LSTP Report (Rev. 1), fig. 4-2 at 4-4 (Non-publicly available).

303 Exhibit INT001-R-00-BD01 at 15-16.

304 Exhibit INT021-00-BD01, MPR-4273, LSTP Report (Rev. 1) at 4-4-4-5 (Non-publicly available); Exhibit NRC001-R-00-BD01, Staff Testimony at 57.

305 Exhibit NRC001-R-00-BD01, Staff Testimony at 57.

design basis for anchor bolts. 306 Second, consistent with industry standards and accepted practices that the path through which load is transferred from an anchor to concrete is the primary consideration for the selection of representative anchors, the program used Hilti Kwik Bolt 3 expansion anchors and Drillco Maxi-Bolt undercut anchors. 307 Hilti Kwik Bolt 3 expansion anchors are the current standard at Seabrook and are similar to the Hilti Kwik Bolt 1 and 2 anchors that have been previously installed at Seabrook. 308 Drillco Maxi-Bolt is the only undercut anchor used at Seabrook. 309 Third, the program was performed at various levels of ASR expansion, on anchors installed before and after ASR development, and using a range of anchor sizes and embedment depths consistent with the anchor population at Seabrook. 310 C-10 did not provide any support to challenge the Anchor Test Program; as stated by Dr.

Saouma, I have not reviewed any aspect of the anchors 311 and I confess full ignorance about anchors. 312

c. Board Findings on the Representativeness of the Reinforcement Anchorage Test Program 2.94 We find that NextEra has demonstrated by a preponderance of the evidence that the Reinforcement Anchorage Test Program was representative of ASR-affected reinforced concrete structures at Seabrook for four reasons. First, the program used representative control 306 See Exhibit NRC001-R-00-BD01, Staff Testimony at 30-31.

307 See id. Hilti Kwik Bolt 3 expansion anchors were used for the transfer of load from the bolt to the concrete using the frictional resistance of the expansion wedge on the concrete and Drillco Maxi-Bolt undercut anchors were used for the transfer of load to concrete using a positive bearing surface. Id.

308 See id.; Tr. at 673. Hilti Kwik Bolt 1 and 2 anchors are no longer readily commercially available. Tr. at 672.

309 See Exhibit NRC001-R-00-BD01, Staff Testimony at 30-31; Tr. at 671-74.

310 Exhibit NRC001-R-00-BD01, Staff Testimony at 30-31.

311 Tr. at 265.

312 Id. at 674.

and test specimens of differing levels of ASR that each contained reinforcement lap splices at the center constant moment region. 313 Second, the program used a large number of load tests to failure. 314 Third, its results were consistent and repeatable. 315 Fourth, the flexure strength of the test specimens exceeded that of the control and the nominal flexural capacity calculated based on the ACI code provisions. 316 Additionally, the Reinforcement Anchorage Test Programs results were similar to those reported in a recently published journal article. 317 2.95 With respect to compression, existing literature provides that ASR expansion does not reduce the compression capacity of confined concrete in its structural context. 318 The results of the Reinforcement Anchorage Test Program were consistent with this existing literature; if compression capacity had been reduced, a compression zone failure would have occurred in the test specimens before the full flexural capacity was realized, which was not observed here. 319 Therefore, for the same reasons that the Reinforcement Anchorage Test Program was representative, we find that NextEras conclusion regarding compression was also representative of ASR-affected reinforced concrete structures at Seabrook within the expansion limits achieved during the testing. 320 313 See Exhibit NRC001-R-00-BD01, Staff Testimony at 32-33.

314 See id.

315 See id.

316 See id.

317 See id.; see also Exhibit NRC057-00-BD01, M. Kathleen Eck Olave, et. al., Performance of RC Columns Affected by ASR. II: Experiments and Assessment, Vol. 20. ASCE J. of Bridge Engg (March 2015) (published online June 12, 2014) (ML19205A485) (Non-publicly available).

318 See Exhibit NRC001-R-00-BD01, Staff Testimony at 34.

319 See id.

320 See id.

2.96 With respect to reinforcement fracture, the existing literature identifies examples of reinforcement fracture in ASR-affected reinforced concrete structures, but only in bend diameters smaller than those permitted by U.S. design codes. 321 FSEL performed bend tests of rebars bent to the allowable limits of Seabrook design codes and did not see evidence of compression crack formation. 322 Based on the combination of the existing literature and the results of the bend tests, NextEra concluded that the reinforcing bars in the ASR-affected reinforced concrete structures at Seabrook are not susceptible to brittle fracture. 323 We agree with the Staffs conclusion that this determination was bounding for Seabrook. 324 Dr. Saouma also agreed that the reinforcing bars in the ASR-affected reinforced concrete structures at Seabrook are not susceptible to brittle fracture. 325 2.97 The LSTP also assessed the issue of seismic response. 326 The LSTP showed that, for heavily loaded members (i.e., members with flexural cracking), the flexural stiffness increased as ASR expansion increased within the expansion levels tested. 327 The Seabrook design-basis seismic-ground-response spectrum shows that seismic demands decrease for frequencies larger than approximately 3 Hz. 328 Since all the structures at Seabrook have a natural frequency of at least 4 Hz and since an increase in stiffness will increase a structures 321 See id. at 35.

322 See id.

323 See id.

324 See id.

325 Tr. at 743-45 ([Brittle fracture] does not concern me. That is unlikely to happen at Seabrook.); id. at 1137 (I believe I have mentioned yesterday that Im not consider [rebar rupture] as a factor for Seabrook.).

326 See Exhibit NRC001-R-00-BD01, Staff Testimony at 35-39.

327 Id. at 35-36; Exhibit NRC007-00-BD01, UFSAR § 3.7(B); Exhibit INT024-00-BD01, SE, encl. 2 at 20; see Exhibit INT012-00-BD01, MPR-4288 (Rev. 0), Structure Deformation Report, fig. 6-1 at 6-6.

328 Exhibit NRC001-R-00-BD01, Staff Testimony at 36; Exhibit INT024-00-BD01, SE, encl. 2 at 20.

frequency, the Staff noted that, for heavily loaded members, ASR will not have an adverse impact on seismic response. 329 Conversely, the LSTP showed that, for lightly loaded members (i.e., members with no flexural cracking), the flexural stiffness decreased as ASR expansion increased within the expansion levels tested. 330 This is not a concern with respect to the Seabrook design-basis seismic-ground-response spectrum because (1) all the structures at Seabrook have a natural frequency of at least 4 Hz, (2) the Seabrook seismic design uses a +/-

10% peak broadening in the response spectra, and (3) there is a square root relationship between stiffness and natural frequency. Therefore, the Staff noted that, for lightly loaded members, this reduction in flexural stiffness will not have a significant impact on the seismic response of the structure for the amount of ASR observed at Seabrook. 331 Based on its review, the Staff concluded that the LSTP was bounding for Seabrook with respect to seismic response. 332 Nothing in the record leads this Board to a conclusion different than the Staff on the issue of seismic response.

d. Board Findings on the Representativeness of the Instrumentation Test Program 2.98 The Instrumentation Test Program evaluated, over a one-year period, three candidate instruments for measuring through-thickness expansion: a vibrating wire deformation meter (VWDM), a snap-ring borehole extensometer (SRBE), and a hydraulic borehole extensometer. 333 The program evaluated these instruments on a representative large-scale 329 Exhibit NRC001-R-00-BD01, Staff Testimony at 36; Exhibit INT024-00-BD01, SE, encl. 2 at 20.

330 Exhibit NRC001-R-00-BD01, Staff Testimony at 36; Exhibit INT024-00-BD01, SE, encl. 2 at 20.

331 Exhibit NRC001-R-00-BD01, Staff Testimony at 35-77; Exhibit INT024-00-BD01, SE, encl. 2 at 20.

332 Exhibit NRC001-R-00-BD01, Staff Testimony at 35-39; Exhibit INT024-00-BD01, SE, encl. 2 at 20.

333 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 20-21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.1 at 5-16; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1)

§ 5.4.1 at 5-16.

beam test specimen with regard to quality of data, ease of installation, and reliability. 334 In particular, the program involved installing the extensometers at different points in time to capture different levels of ASR expansion. The program then tracked how the extensometers performed over time by comparing the measurements from the extensometers against mechanical measurements of the thickness of the beam, which was accomplished with boreholes on either side of each extensometer and a depth micrometer. 335 2.99 We find that NextEra has demonstrated by a preponderance of the evidence that the Instrumentation Test Program properly determined that the SRBE was the best instrument for measuring through-thickness expansion for six reasons. First, its data agreed closely with the reference data. 336 Second, it directly measures physical expansion. 337 Third, it does not rely on additional equipment. 338 Fourth, it contains no electronics and does not require field calibration. 339 Fifth, it did not exhibit reliability problems. 340 Sixth, it was easier to install than 334 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

335 Tr. at 1043.

336 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18; Tr. at 1044.

337 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

338 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

339 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

340 Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17 18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

the VWDMs. 341 NRC inspectors who were on site at the LSTP performed an independent review of the Instrumentation Test Program, which assessed the efficacy of strain gauges against pin-to-pin strain measurements and verified that the program was valid. 342 Therefore, the Staff determined that there was reasonable assurance that the use of SRBEs to measure future through-thickness expansion of Seabrook structures would be effective. 343 2.100 C-10 argued that instead of SRBEs, the Damage Rating Index (DRI) method should be used to characterize through-thickness expansion. 344 As noted in the FHWA Report, while the DRI method may be useful for quantitative assessment of internal damage in concrete, there is no standard procedure for its use. 345 The method is fairly subjective and the results can be quite variable from one petrographer to another. 346 Even Dr. Saouma cautioned that [DRI]

is a delicate test that should only be performed by a very qualified petrographer, and should be performed repeatedly by the same one. 347 Instead of relying on a delicate test and only one dedicated petrographer, NextEra chose to use an SRBE installed to a depth almost through the entire thickness of the concrete member (i.e., within a few inches of the far surface) to monitor 341 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21; NRC008-00-BD01, MPR-4273 (Rev. 0) § 5.4.2 at 5-17-5-18; Exhibit INT019-R-00-BD01, MPR-4273 (Rev. 1) § 5.4.2 at 5-17-5-18.

342 Tr. at 1041-43 ([D]uring their seven visits to [FSEL, the Staff] witnessed all test activities including the extensometers. They saw them in use. And they saw the different varieties of instruments that [were]

tested.) (Mr. Simons).

343 Exhibit NRC001-R-00-BD01, Staff Testimony at 39-40; Exhibit INT024-00-BD01, SE, encl. 2 at 21.

344 Exhibit INT001-R-00-BD01 at 20, 31-32. DRI evaluates the condition of concrete by counting the number of typical petrographic features of ASR on polished concrete sections. Exhibit NER013 BD01, FHWA Report at 25.

345 Exhibit NER013-00-BD01, FHWA Report at 96.

346 Id.

347 Exhibit INT001-R-00-BD01 at 31.

through-thickness expansion progression. 348 The Staffs review of the SRBE method of measuring through-thickness expansion found this approach effective. 349 The Staff also determined that the SRBE method provides a more accurate and meaningful measure of through-thickness expansion than the DRI method. 350 Nothing in the record leads this Board to a conclusion different than the Staff on the issue of the Instrumentation Test Program.

F. The Adequacy of the Seabrook ASR Expansion Monitoring Programs Monitoring, Acceptance Criteria, and Inspection Intervals Derived from the LSTP 2.101 The Seabrook ASR expansion monitoring program measures cracks in ASR-affected concrete, first in the in-plane direction using CI/CCI and then, when in-plane expansion reaches a specified threshold, in the through-thickness direction using (1) a calculation to determine to-date expansion and (2) an SRBE to measure expansion thereafter. 351 The purpose of this monitoring program is to ensure that the in-plane, through-thickness, and volumetric expansions remain below the expansion limits, which ensures that the structural performance of the Seabrook reinforced concrete structures can still be conservatively estimated by the design basis codes. 352 2.102 NextEra used the data from the LSTP to develop various aspects of the ASR expansion monitoring program. First, the programs ASR expansion limits are from the LSTP. 353 For the Shear and Reinforcement Anchorage Test Programs, the LSTP determined that there 348 Exhibit NRC001-R-00-BD01, Staff Testimony at 65.

349 Id.

350 Id. at 39-40.

351 Id. at 18-19; Exhibit INT024-00-BD01, SE, encl. 2 at 21-22, 53-55.

352 Exhibit NRC001-R-00-BD01, Staff Testimony at 19; Exhibit INT024-00-BD01, SE, encl. 2 at 21-22, 25, 53-55. See also Tr. at 331 ([T]he whole point of this entire project, is to know where we are, and stay inside that box that's defined by the testing program that shows that we're still inside that design basis.).

353 Exhibit NRC001-R-00-BD01, Staff Testimony at 41-42, 45.

was no adverse effect on structural limit states at the expansion levels tested. 354 Therefore, NextEra used the lower of the highest through-thickness expansion levels tested in the Shear and Reinforcement Anchorage Test Programs, which was for shear, as the ASR expansion limit for the shear, flexure, and reinforcement anchorage structural limit states. 355 For the Anchor Test Program, the LSTP found that anchor capacity is insensitive to through-thickness expansion and time of installation relative to ASR expansion. 356 Therefore, NextEra set the ASR expansion limit for the anchors structural limit state to the greatest percentage of in-plane expansion that was tested without showing a reduction in anchor capacity. 357 2.103 Second, NextEra set the point at which to transition from measuring in-plane expansion to measuring through-thickness expansion at 0.1% in-plane expansion. 358 The Staff determined that this approach was appropriate because it was consistent with the data obtained from the LSTP and also corresponds to a very low level of ASR degradation. 359 As discussed below, when making this transition, the through-thickness expansion to date is calculated. In all instances, the calculated through-thickness expansion to date at 0.1% in-plane expansion at Seabrook has been much, much less than the through-thickness limit and even the highest expansion calculated was significantly less than the limit. 360 Therefore, according to NextEra expert witness Mr. Simons, So that tells you that the criterion of installing extensometers around [0.1%] is appropriate. It says its not gotten far away from us. It hasnt gotten so close to 354 Id. at 26-27.

355 Id.

356 Id.

357 Id.

358 Id.

359 Id.; Tr. at 518 ([NextEra] is only using CCI up to a very small expansion which then they switch to the volumetric measurement and also through wall thickness.).

360 Tr. at 510.

our limit that we need to be concerned about it. 361 Similarly, NextEra expert witness Mr. Bagley stated that, even if, as postulated by C-10 expert witness Dr. Saouma, there was some delay in surface crack manifestation as compared to interior cracking, the ASR expansion monitoring program would require the measurement of through-thickness expansion well before the limits are reached. 362 This aspect of the ASR expansion monitoring program is also consistent with the FHWA Report guidance of using CI/CCI as an initial monitoring tool. 363 Dr. Saouma agrees that everybody recommends initiating the crack index as the starting point. 364 2.104 Third, NextEra developed an equation to calculate through-thickness expansion to date in Seabrook concrete. 365 The Staff determined that this calculation was appropriate because it was consistent with the LSTP data and the existing literature data and incorporated conservativisms. 366 Specifically, to develop the equation, NextEra reviewed data from the LSTP and from the existing literature and determined that the reduction in concrete elastic modulus is more sensitive to ASR development than other properties that have been studied. 367 Therefore, using the LSTP data, NextEra developed an equation to correlate normalized elastic modulus and through-thickness expansion (correlation equation). 368 NextEra compared literature data to this equation and noted that the trend from the literature data compared favorably with the 361 Id.

362 Id. at 548.

363 See id. at 510-11, 1132.

364 Id. at 328-29; see also id. at 494 (I am not disputing that [CI/CCI] is the very first line of defense.).

365 Exhibit NRC001-R-00-BD01, Staff Testimony at 42.

366 Id.

367 Id.

368 Id.

equation. 369 The Staff independently determined that the equation was really close to the best available data that it could find in the literature. 370 Additionally, since the calculation of the normalized elastic modulus requires the calculation of the original (28-day) modulus of the affected Seabrook concreteeither through estimation or the use of Seabrook concrete not impacted by ASRNextEra applied a reduction factor to the correlation equation, which conservatively overestimated the expansion. 371 Specifically, the reduction factor attempts to bound the data from the LSTP. 372 Conservatism is also introduced by the fact that NextEra is measuring the worst portion of a particular wall at Seabrook (i.e., the portion with the most significant surface cracking) and assuming that the entire wall is in that condition. 373 2.105 Fourth, the monitoring intervals are derived from the LSTP and the Staff independently determined that they are conservative. 374 Once SRBEs are installed at 0.1% in-plane expansion, which, as discussed above, is already conservative, the monitoring interval is similarly conservatively reduced to once every six months. 375 Staff expert witness Ms. Buford stated that the Staff did not have any concern that the structural integrity could be challenged within the [six months] time before the next inspection based on the literature and the data obtained at Seabrook to date. 376 Staff expert witness Mr. Lehman similarly stated that the Staff hasnt seen any evidence at Seabrook or in the literature of ASR occurring more quickly than a 369 Id.

370 Tr. at 1117-21.

371 Id.; Exhibit INT024-00-BD01, SE, encl. 2 at 22-23; Exhibit NRC011-00-BD01, MPR-4153 ASR Monitoring Report (Rev. 2) § 3.3.

372 Tr. at 544-46.

373 Id. at 480, 543-48, 1147.

374 Id. at 420-21, 1121-24.

375 Id. at 1124.

376 Id. at 692-95.

time period on the order of years except in experiments where ASR is purposefully being accelerated. 377 Therefore, even if Seabrook was experiencing the most rapid rate of ASR expansion, the six-month monitoring frequency would not be challenged. 378 In fact, to date, NextEra has measured a 0.02 percent per year through-thickness expansion meaning that, even at the location with the highest through-thickness expansion, this rate could increase 1,000 percent in six months and the location would still be well below the limit. 379 2.106 Based, in part, on its determination that NextEra appropriately used the LSTP data to develop the ASR expansion monitoring program, the Staff concluded that NextEra has provided reasonable assurance that Seabrook will continue to meet the applicable NRC requirements and will not endanger the health and safety of the public. 380 2.107 As explained in detail as follows, we find that NextEra has demonstrated by a preponderance of the evidence that the aspects of the Seabrook ASR expansion monitoring program derived from the LSTP are adequate.

a. Board Findings on the Use of the CI/CCI Method 2.108 CI/CCI is a commonly used conservative method for monitoring crack progression or in-plane expansion due to ASR, as discussed in ASR-monitoring specific guidance documents. 381 For example, the FHWA Report recognizes CI/CCI as an in-situ 377 Id. at 1126-27.

378 Id. at 1121-24.

379 Id. at 685-86, 695-96, 1135-36, 1194, 1202.

380 Exhibit INT024-00-BD01, SE, encl. 2 at 31-32.

381 Exhibit NRC001-R-00-BD01, Staff Testimony at 62; Exhibit NER013-00-BD01, FHWA Report; see also Tr. at 482-83 (The use of cracking index at Seabrook and at all other structures in the United States and around the world is not done on the basis of [the LSTP]. It's done on the basis of best practices recommendations pulled together by industry experts. Some of those experts have been named by Dr.

Saouma in his testimony. They pulled together the [FHWA Report] that does make explicitly recommendation on crack indexing twice a year. The second document is Institutional Structural Engineers from the United Kingdom. Last but not least [t]he Swiss dam document that Dr. Saouma references, that [described] cracking index being the golden standard on this activity.).

method that gives a quantitative assessment of the extent of cracking in structural members, which is related to the overall amount of expansion reached in the affected concrete member. 382 The FHWA Report includes CI/CCI and monitoring of deformations/movements as recommended in-situ methods that can be used for estimating the expansion to date in ASR-affected concrete members. 383 This is exactly what was done by NextEraat Seabrook, CI/CCI is used to estimate the expansion-to-date in the in-plane direction of ASR-affected structures. 384 Moreover, the use of CI/CCI is conservative because, although surface cracking can also be influenced by other mechanisms such as temperature variation, drying and wetting cycles, and shrinkage, all the cracking is attributed to ASR. 385 Therefore, the Staff determined that the use at Seabrook of CI/CCI to characterize and monitor the progression of in-plane ASR expansion is consistent with industry practice and acceptable. 386 2.109 C-10 argued, however, that at Seabrook, CI/CCI must be ruled out completely as a monitoring measure. 387 C-10 expert witness Dr. Saouma theorized that because of gradients within the Seabrook walls that may exist with respect to humidity and temperature, coupled with the rebar being located close to the surface of the walls, cracking on the surface of the walls will not be representative of cracking in the interior. 388 2.110 The Staff testified that Dr. Saoumas theory was not a concern because the LSTP was representative of the structures at Seabrook and interior cracking without surface 382 Exhibit NRC001-R-00-BD01, Staff Testimony at 62; Exhibit NER023-00-BD01, FHWA Report at 23.

383 Exhibit NER023-00-BD01, FHWA Report at 23, 31.

384 Exhibit NRC001-R-00-BD01, Staff Testimony at 62-63.

385 Id.; Tr. at 453-54; see Tr. at 1156 (Dr. Saouma stating that shrinkage did occur at Seabrook).

386 Exhibit NRC001-R-00-BD01, Staff Testimony at 62-63.

387 Exhibit INT001-R-00-BD01 at 21.

388 See Tr. at 1132.

cracking was not observed during the LSTP; instead, the LSTP demonstrated that interior and surface cracking advanced together until surface cracking plateaued. 389 At that point, which is a very low ASR severity, monitoring at Seabrook moves from CI/CCI to through-thickness. 390 The Staff testified that it hasnt seen, in either the literature or the [LSTP], any evidence of there being no indications of ASR in the planar directions visible, and then significant ASR occurring through the thickness of the concrete. 391 Additionally, 200 cores have been taken at Seabrook and none of them showed internal cracking without surface cracking. 392 Therefore, the Staff concluded that it has reasonable assurance that there is not extensive damage happening that is not visible - that wouldnt be visible by either in-plane cracking or some sort of deformation, which is being monitored and managed in a separate program. 393 2.111 Dr. Saouma argues, by reference to Figure 1 in the FHWA Report, 394 that Section 2.2 of this report indicates that CI/CCI can only be used in conjunction with petrography. 395 Section 2.2 of the FHWA Report is entitled, ASR Investigation Program Level 2: Preliminary Studies for the Diagnosis of ASR, and the portion of its Figure 1 to which Dr.

Saouma refers is marked as Level 2 Preliminary Investigation Program. 396 And further examination of the context of the FHWA Reports recommendation to use petrography in 389 Tr. at 1132-33.

390 Id.

391 Id.

392 Id. at 1097-98.

393 Id. at 1133-34. See also id. at 554 (NextEra expert witness Dr. Bayrak stating that [t]here's always surface manifestation of what goes on inside in my experience).

394 Although Dr. Saouma refers to this Figure as Figure 12, the cited figure is Figure 1 in the FHWA Report. Exhibit NER023-00-BD01, FHWA Report at 5.

395 Exhibit INT001-R-00-BD01 at 19-20.

396 Exhibit NER023-00-BD01, FHWA Report at 3, 5.

addition to CI/CCI only shows that this recommendation relates to the early detection and diagnosis of ASR in concrete. 397 This guidance, therefore, is not relevant to Seabrook: ASR has already been diagnosed and confirmed at Seabrook based on the petrographic examination of cores. Further, NextEra has conservatively decided to attribute any future visual indications of concrete degradation to ASR, which means that the detection and diagnosis contemplated in the FHWA report is not necessary here. 398 2.112 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the use of the CI/CCI Method was appropriate.

b. Board Findings on the Possibility of Delamination Cracks Without Surface Indication in Seabrook Structures 2.113 C-10 expert witness Dr. Saouma argued that delamination cracks may form inside the walls of Seabrook and that these cracks will not be capable of detection by surface measurements of CI/CCI. 399 Dr. Saouma theorized that such internal and hidden/sleeping crack[s] may result from the perfect storm of (1) the expansion being out of plane because it is constrained in the other two directions, (2) the cracks propagating vertically because the wall is under compression, and (3) tensile stress in the orthogonal direction because of the axial longitudinal compression. 400 Dr. Saouma did not provide any support for this theory as part of his pre-filed written testimony except for two pictures, which he claimed to be [e]xamples of ASR driven delamination in surface reinforced concrete retaining walls in Switzerland. 401 He 397 Exhibit NRC001-R-00-BD01, Staff Testimony 62.

398 Id.

399 Exhibit INT028-00-BD01 at 28-33; see also Tr. at 557 ([T]here is a possibility - a very strong possibility of having an internal hidden crack, which does not manifest itself on the surface.).

400 Exhibit INT028-00-BD01 at 30, 33.

401 Id. at 32-33.

only attributed these pictures as Courtesy Dr. Leemann, EMPA, Switzerland. 402 At the evidentiary hearing, Dr. Saouma testified that the source of these pictures was a Swiss document. 403 He stated that C-10 intended to submit this document into evidence. 404 Subsequently, C-10 stated that it would not try to introduce the source of the pictures into evidence; 405 therefore, the pictures are wholly unsupported. Instead of the pictures, C-10 stated that it would rely on Dr. Saoumas testimony regarding the ISE Report. 406 Specifically, Dr.

Saouma testified that the ISE Report provides that when there [are] two planes of reinforcement and no reinforcement in between. We start with microcracking, which eventually can coalesce into [macrocracks]. 407 2.114 NextEra and the Staff demonstrated that nothing in the literature, nothing in the data from Seabrook, and nothing from the LSTP supports Dr. Saoumas theory that delamination cracks can occur at Seabrook without surface indications.

2.115 With respect to the literature, as recognized by NextEra expert witness Dr.

Bayrak, there is no way of telling from the pictures provided by Dr. Saouma whether the retaining walls have anything in common with the structures at Seabrook. 408 Additionally, the pictures do not represent hidden cracks because the cracks are visible. 409 Finally, the tops of 402 Id.

403 Tr. at 557.

404 Id.

405 Id. at 959.

406 Id. ([C-10] will not try to introduce [into evidence the Swiss article], and will rely on [Dr. Saoumas]

testimony about [Exhibit NER-012].).

407 Id. at 890-91.

408 Id. at 563 ([W]e have no idea about the structural details of what we're looking at here and what condition led up to this cracking.).

409 Tr. at 563, 572.

the walls in the pictures are exposed to the environment where the cracks are visible, whereas the tops of the walls at Seabrook are not. 410 2.116 With respect to the data from Seabrook, as part of the Seabrook structures monitoring program, NextEra document[s] essentially every crack that is located and evaluate[s] it. 411 NextEra has taken over 200 cores and inspected them and not seen any evidence of delamination. 412 The Staff independently observed the removal of cores at Seabrook and similarly is not aware of any instance where there was any sort of delamination identified. 413 2.117 With respect to the LSTP, as ASR progressed in test specimens, a relatively large crack was observed near the center of the surfaces between the reinforcement mats, as depicted in Figure 4-2 of MPR-4273. 414 Dr. Saouma argued that this is an example of a delamination crack and that there is a strong likelihood that a similar phenomenon would occur at Seabrook. 415 2.118 NextEra, however, confirmed that this crack was an edge effect that penetrated only a few inches into the specimen. 416 NextEra did this by taking cross sections of the affected section of the test specimen. 417 NextEra noted that the cracks were essentially straight lines 410 Id.

411 Id. at 573.

412 Id. at 572.

413 Id. at 560.

414 Exhibit NRC001-R-00-BD01, Staff Testimony at 57; Exhibit INT021-00-BD01, MPR-4273, LSTP Report (Rev. 1), fig. 4-2 at 4-4 (Non-publicly available).

415 Tr. at 561-62.

416 Exhibit INT021-00-BD01, MPR-4273, LSTP Report (Rev. 1) at 4-4-4-5 (Non-publicly available); Exhibit NRC001-R-00-BD01, Staff Testimony at 57; Tr. at 564-66.

417 Tr. at 564-66; Exhibit NER022-R-00-BD01 at PDF page 880.

as opposed to the curled up shape that Dr. Saouma testified that a delamination crack would take. 418 NextEra also noted that the thickness of the specimens was measured and that there was no discernible curling, instead, the sides remained fairly flat. 419 Further, NextEra demonstrated that the summation of crack widths through the length of the specimen added up to the same level of expansion, in that there were fewer cracks at the surface, but they were wider; whereas there were more cracks at the center of the specimen, but they were narrower. 420 Therefore, NextEra explained that the cracks were a consequence of using beams that were essentially cut-outs from a structural wall. 421 Specifically, if, as in the actual walls at Seabrook, each of these beams were stacked on top of each other, there would be no edge regions exposed to the environment and, thus, no cracks on the edges. 422 Consequently, NextEra determined that these cracks were edge effect cracks and are not expected to occur in Seabrook structures due to the confinement effects provided by adjoining structural members. 423 2.119 Because the LSTP did not identify delamination cracks, NextEra expert witness Dr. Bayrak concluded that, even if the ISE Report demonstrates that delamination cracking is possible, there is no indication that it will occur in Seabrooks walls. 424 2.120 Finally, even if delamination cracking were to occur in Seabrooks walls, as with all other internal cracking, it would be accompanied by surface cracking. Because SRBEs are 418 Tr. at 565.

419 Id. at 566-67 (discussing Exhibit NER022-R-00-BD01 at PDF page 57).

420 Id. at 567-68 (discussing Exhibit NER022-R-00-BD01 at PDF page 111).

421 Id. at 568-69.

422 Id.

423 Id.

424 Tr. at 1002-03.

installed at surface cracking that meets the conservatively low level threshold of in-plane expansion of 0.1%, the corresponding delamination cracking would be actively monitored by an SRBE. 425 This addresses Dr. Saoumas concern that SRBEs may not be installed at the actual locations of ASR hot-spots. 426 2.121 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the monitoring method selected was appropriate.

c. Board Findings on Testing to Maximum ASR Expansion 2.122 C-10 argued that the lack of accelerated expansion testing precludes NextEra from reaching any conclusions about the maximum likely degree of expansion. 427 2.123 C-10 is correct that NextEra did not run tests to estimate the remaining ASR expansion or to predict when ASR would stop occurring at Seabrook; however, C-10 did not explain why this is a safety concern. 428 NextEra has chosen a different engineering evaluation approach to ensure the safety of Seabrook structures that does not involve predictions of ASR kinetics and ultimate expansion. 429 The Staff determined that NextEra has identified reasonable and justifiable expansion limits, which account for potential future expansion, by setting the maximum level of expansion at which the code acceptance criteria are met. 430 Further, NextEra is actively monitoring structures to ensure that they remain within these limits. 431 The ultimate expansion of ASR at Seabrook is not relevant to the approach chosen by NextEra because 425 Id. at 1132-33.

426 Exhibit INT028-00-BD01 at 31.

427 Exhibit INT001-R-00-BD01 at 11, 26, 31.

428 Exhibit NRC001-R-00-BD01, Staff Testimony at 71-72.

429 Id.

430 Id.

431 Id.

under the approach approved in the LAR, NextEra will monitor the Seabrook structures to ensure that their expansion remains below the limits from the LSTP. 432 2.124 At the hearing, C-10 expert witness Dr. Soauma conceded that testing to maximum expansion is not necessary. 433 2.125 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that testing to maximum ASR expansion is not necessary.

d. Board Findings on Knowing the Rate of ASR Expansion at Seabrook 2.126 C-10 stated that a [s]igmoid curve representative of [ASR] expansion can be obtained from accelerated expansion tests. 434 The Staff agreed that a sigmoid curve can generically describe the general progression of ASR, 435 and that there is no such curve specific to the ASR at Seabrook. 436 2.127 C-10 argued that NextEras failure to account for the progression of ASR over a sigmoid curve at Seabrook undermined the reliability of NextEras assessment of ASR at Seabrook. 437 Therefore, although conceding that testing to maximum expansion was not necessary, C-10 expert witness Dr. Saouma maintained that [w]e need to know where we are on that curve 438 because it is important in the context of assessing when the next 432 Id.

433 Tr. at 386 (We don't want to expand it all the way failure, that to ultimate expansion, that's fine.); Tr.

at 401 (No, we're not talking about the final point.).

434 Exhibit INT001-R-00-BD01 at 32.

435 Tr. at 401-02.

436 Id. at 404.

437 C-10 Research and Education Foundation, Inc. Rebuttal Statement of Position on C-10s Contentions Regarding NextEras Program for Managing ASR at Seabrook Station Nuclear Power Plant, at 5-6 (Aug.

23, 2019) (ML19235A317); Exhibit INT028-00-BD01 at 12-13; Tr. at 386.

438 Tr. at 386.

inspection should be. 439 Further, he opined, without support, that Seabrook is most likely in the very early slower phase, but the rate of expansion will accelerate at some point. 440 2.128 NextEra expert witness Mr. Sherman described the generic sigmoid curve as consisting of a dormant period, an active period, and a period where [ASR is] petered out. 441 He stated that the modulus testing at Seabrook places Seabrook in the active period 442 or, as NextEra expert witness Mr. Simons called it, the steep part of the curve beyond the inflection point. 443 Mr. Simons concluded that even on the steep part of the curve, there is decades of margin before an expansion limit would be reached and, thus, clearly a six-month interval is completely acceptable for monitoring. 444 2.129 The Staff testified that where Seabrook is on the sigmoid curve had no bearing on [its] reasonable assurance determination. 445 This is because, given that through-thickness expansion is measured starting at the relatively small in-plane expansion level of 0.1% 446 and because it is measured every six months, even the fastest possible expansion could not result in the exceedance of the expansion limits before the end of the monitoring interval. 447 This is borne out by the data obtained at Seabrook to date and the data in the literature. 448 For 439 Id. at 413-15.

440 Exhibit INT028-00-BD01 at 12-13.

441 Tr. at 387.

442 Id. at 389-90.

443 Id. at 399-400; 415. The Staff also pointed out that, according to the ISE Report, once cracking is established, cracks grow at a broadly linear rate. Id. at 1124 - 25 (citing Exhibit NER012 at PDF page 4).

444 Id. at 415-16.

445 Id. at 1122-23.

446 Tr. at 518.

447 Id. at 1121-24.

448 Id. at 692-95, 1126-27.

instance, the current rate of expansion at Seabrook could increase 1,000 percent in six months in the location with the highest through-thickness expansion and still be well below the limit. 449 Even in the LSTP where all the factors were manipulated to accelerate expansion, it still took on average a year to get to the expansion limits. 450 Moreover, the Staff stated that [t]here has been no case history where we [have] seen that ASR was the primary cause of the structural failure of collapse and that the risk related to ASR is relatively low, provided it's monitored and managed. 451 Therefore, knowing the rate of ASR expansion at Seabrook was not necessary for the Staff to conclude that the license amendment provided reasonable assurance that Seabrook will continue to meet the applicable NRC requirements and will not endanger the health and safety of the public. 452 2.130 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that knowing the rate of ASR expansion at Seabrook is not necessary.

e. Board Findings on the Use of the Correlation Equation to Calculate Through-Thickness Expansion to Date 2.131 As discussed previously, when in-plane expansion at a particular location, as measured by CI/CCI, reaches 0.1%, an SRBE is installed to measure through-thickness expansion going forward. Through-thickness expansion up to the date of the installation of the SRBE, however, is calculated using an equation to correlate normalized elastic modulus and through-thickness expansion (correlation equation). 453 To obtain the normalized elastic 449 Id. at 685-86, 695-96, 1135-36, 1194, 1202.

450 Id. at 397.

451 Id. at 1115.

452 Tr. at 1122-23; 1126-27.

453 Exhibit NRC001-R-00-BD01, Staff Testimony at 42.

modulus for use in this equation, it is necessary to know the original (i.e., 28-day) modulus of the affected Seabrook concrete; however, this elastic modulus was not measured during Seabrooks construction. 454 Therefore, NextEra provided two approaches by which the original modulus could be determined(1) use the equation from ACI 318-71, Section 8.3.1455 to estimate the modulus based on the measured 28-day compressive strength of concrete cylinders cast at the time of Seabrook construction or (2) use reference Seabrook cores representative of original construction and not affected by ASR. Because both approaches can introduce uncertainty, NextEra applied a reduction factor to the normalized modulus term of the correlation equation, which would conservatively result in overestimating the through-thickness expansion to date in Seabrook structures. The reduction factor attempts to bound the data from the LSTP. 456 2.132 Based on considerations of statistical measures of goodness of fit, the Staff determined that the correlation equation was reasonable because it accounts for a large majority of the variance in the LSTP data, as well as similar trends seen in the existing literature data. 457 2.133 Besides the reduction factor, the correlation equation involves numerous conservatisms. First, the equation naturally gets more sensitive as you get to greater levels of degradation. 458 Since SRBEs are installed at a very low level of in-plane expansion, this means that any potential error would largely be muted. 459 This is borne out by the through-454 Exhibit NRC090-00-BD01 at 2-3.

455 Exhibit NRC049-00-BD01 at 22.

456 Tr. at 544-46.

457 See Exhibit NRC090-00-BD01 at 3.

458 Tr. at 558-59.

459 Id. at 559.

thickness expansions measured to date, which have primarily been very low. 460 Second, the ASR expansion monitoring program assumes that the entire wall has the through-thickness expansion calculated for the location of the installation of the SRBE, which is the portion of the wall with the most significant surface cracking. 461 Third, the correlation equation is subject to a license condition, which requires a confirmatory corroboration study of the equation on Seabrook structures to provide additional assurance of the continued applicability of the equation. The corroboration study is required to cover at least 20 percent of extensometer locations on Seabrook ASR-affected structures and to use the approach provided in Appendix C of Report MPR-4273, Revision 1. It is required to be completed no later than 2025, with a follow-up study 10 years thereafter, and NextEra is required to notify the NRC each time a study is completed. Finally, NextEra has a continuing obligation to demonstrate that its structures can perform their functions. Therefore, if, based on the results of a corroboration study, the Staff were ever to question whether the design basis codes, as modified and supplemented, were no longer valid, NextEra would be required to demonstrate operability or update the Seabrook licensing basis. 462 Similarly, NextEra is obligated, through its operating experience and corrective actions programs, to evaluate relevant operating experience and determine whether a change to its programs is needed. 463 2.134 C-10 expert witness Dr. Saouma argued that the correlation equation carries substantial uncertainties. 464 He based this argument, in part, on his belief that the normal 460 Id.

461 Id. at 480, 543-48, 1147.

462 Id. at 575.

463 Id. at 1136-37.

464 Exhibit INT028-00-BD01 at 36; Exhibit INT030-R-00-BD01 at 1.

variability of +/- 20 percent in the measured data in ACI 318-71 is a margin of error. 465 Rather, the +/- 20 percent is a reference to the variability of the experimental data on which the ACI 318-71 empirical equation for concrete modulus of elasticity was developed. 466 Section 8.3.1 of ACI 318-71 states that for normal weight concrete, the modulus of elasticity (Ec) may be considered to be 57,000fc. 467 The code does not require the modulus of elasticity value calculated using the empirical equation to include a +/- 20 percent margin of error. 468 Therefore, Dr Saouma mischaracterized normal variability in the data underlying the code equation as a margin of error in the code equation. Additionally, the original elastic modulus for locations of installed extensometers at Seabrook is calculated using the average of the 28-day compressive strength data available for the location469 and not just using an individual cylinder test, thereby accounting for variability to obtain a representative modulus for the location and not one that is susceptible to a +/- 20 percent margin of error, as Dr. Saouma asserted. 470 2.135 Similarly, C-10 faulted the correlation equation for not using error bars. 471 However, the correlation equation is used in the context of the design basis codes, which do not use error bars; instead, they incorporate error into their equations. 472 As stated by NextEra expert witness Dr. Bayrak, [w]ith respect to science and engineering and error bars, ACI code committees over the span of the past half a century have successfully conducted reliable 465 Exhibit INT028-00-BD01 at 36-40.

466 Exhibit NRC090-00-BD01 at 4.

467 Exhibit NRC049-00-BD01 at 22.

468 Exhibit NRC090-00-BD01 at 4.

469 Exhibit INT020-00-BD01 at 108-09.

470 Exhibit NRC090-00-BD01 at 4.

471 Tr. at 797.

472 Id. at 780-81, 795.

designs, strong designs, without [en]dangering the public safety in the absence of error bars.

So, the statement that structural engineers must use error bars to ensure safety, or even imply that such is a necessity, is, is just categorically wrong. 473 2.136 Dr. Saouma argued that the correlation equation does not account for the increase in the compressive strength of concrete over time and that this would cause the calculation to underestimate through-thickness expansion. Dr. Saouma asserts that compressive strength after five years can be as much as 20% higher than the value measured at 28 days. 474 Even if this were the case at Seabrook, then the reduction factor in the correlation equation would bound this uncertainty. This is because applying an increase in compressive strength of a factor of 1.2 (i.e., 20 percent) to the ACI 318-71 equation for elastic modulus, which is a function of the square root of compressive strength, would result in the initial modulus being higher by a factor of the square root of 1.2, which is 1.095; consequently, the resulting normalized modulus would be lower by a factor of 0.91 (i.e., 1/1.095). 475 The reduction factor in NextEras correlation equation is smaller than this value and, therefore, adequately accounts for this uncertainty.

2.137 The LSTP had a specification for the range of strength acceptable in the test specimen concrete. 476 Dr. Saouma pointed to this range and stated that, because of this range, there are differences in strength between the LSTP concrete and the Seabrook concrete, which, in turn, create uncertainties in the correlation equation that are not accounted for. 477 The range of strength of the actual test specimens, though, as opposed to the generic specification range, 473 Id. at 784.

474 Exhibit INT030-R-00-BD01 at 1.

475 Exhibit NRC090-00-BD01 at 4.

476 Tr. at 596, 1144.

477 Id. at 1144-46.

is much narrower and it represents strengths typical of concrete structures at Seabrook. 478 As Dr. Bayrak explained, the specification range provided the limits for the test specimens and the narrower range that was actually achieved was the target for the test specimens. 479 Therefore, there is not a representativeness issue and, consequently, there is not an uncertainty related to differing concrete strengths that is not accounted for by the correlation equation.

2.138 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the use of the correlation equation to calculate through-thickness expansion to date is appropriate.

G. NextEras Implementation of the Structure Deformation Monitoring Program is Not Within the Scope of this Proceeding 2.139 The contention admitted in this proceeding, as reformulated by the Board, challenges the LSTP and its data and the proposed monitoring, acceptance criteria, and inspection intervals derived from that data. 480 2.140 C-10 advanced numerous arguments that are unrelated to the LSTP and its data and the proposed monitoring, acceptance criteria, and inspection intervals derived from that data. Specifically, all of C-10s arguments regarding the implementation of the structure deformation monitoring program and the finite element analyses employed in that program are unrelated to the admitted contention.

2.141 As explained above, the LAR at issue in this proceeding is made up of two portionsthe ASR expansion monitoring program and the structure deformation monitoring programand only the former portion is related to the admitted contention. 481 478 Id. at 596-97.

479 Id. at 597-98.

480 LBP-17-7, 86 NRC at 127.

481 See Exhibit INT010-00-BD01, Original LAR at 31-34 of 73 (unnumbered) (discussing each program in a separate section).

2.142 The structure deformation monitoring program addresses the additional ASR-induced structural demand due to cumulative effects of ASR expansion and cracking in combination with other design-basis loads. 482 The structure deformation monitoring program does not rely on LSTP data as direct numerical input for the structural analysis to determine the structural demand under design basis loads, including ASR. 483 As part of the structure deformation monitoring program, the ASR load developed for each ASR-affected structure at Seabrook is estimated based on field data from the actual structures and is not derived from the LSTP. 484 Specifically, the structure deformation monitoring program uses Cl/CCI to estimate the ASR strain in a concrete member. 485 The structure deformation monitoring program may also use other appropriate field measurements (e.g., seismic gaps, annulus gaps, relative displacements, etc.) and observations using commonly used measurement tools. 486 The only overlap of the structure deformation monitoring program with the LSTP is that the programs acceptance criteria are tied to the point at which a structure would meet the limits identified in the LSTP; the entire process used by NextEra to implement the structure deformation monitoring program up to this point, including finite element analyses, is separate from the LSTP. 487 2.143 The bases addressed by the Board in admitting the contention demonstrate that its use of the terms monitoring, acceptance criteria, and inspection intervals 488 is specific to the 482 Exhibit NRC001-R-00-BD01 at 20.

483 Id. at 21.

484 Id.

485 Id.

486 Id. at 21-23.

487 Id.

488 LBP-17-7, 86 NRC at 127.

ASR expansion monitoring portion of the LAR. For instance, in LBP-17-7, the Board discusses whether the LSTP supports CI/CCI, SRBEs, and empirical calculations as valid means of determining ASR expansion at Seabrook (i.e., monitoring), 489 whether the LSTP supports that the ASR expansion limits in LAR Table 4 are applicable to Seabrook (i.e., acceptance criteria), 490 and whether the ASR expansion monitoring intervals in LAR Table 5 are valid at Seabrook (i.e., inspection intervals) 491all of which are discussed in the ASR expansion monitoring portion of the LAR. 492 2.144 The structure deformation monitoring portion of the LAR discusses different monitoring (i.e., finite element analyses of susceptible structures), different acceptance criteria (i.e., threshold monitoring limits that are specific to each structure), and different inspection intervals (i.e., as provided in LAR Table 6). 493 The structure deformation monitoring categories (i.e., Stages 1, 2, and 3) are distinct from the ASR expansion monitoring categories (i.e., Tiers 1, 2, and 3). 494 On this point, it bears noting that C-10 challenged the monitoring intervals in LAR Table 5 and not the monitoring intervals in LAR Table 6. 495 Even Dr. Saouma, when asked during the evidentiary hearing whether the inspection intervals that he was disputing were those in LAR Table 5, stated [t]hats the only one that Im aware of. 496 489 Id. at 98-102; see also id. at 93 (C-10 contests the sufficiency of the methods proposed in the LAR for monitoring the anticipated progression of ASR at Seabrook.).

490 Id. at 106; see also id. at 114 n.353 (We understand that the phrase acceptance criteria, as used by the Staff, refers to the expansion limits in LAR Table 4.).

491 Id. at 124.

492 See Exhibit INT010-00-BD01, Original LAR at 30-32 of 73 (unnumbered).

493 Id. at 23-27, 32-33 of 73 (unnumbered).

494 Id. at 34, tbl. 6.

495 LBP-17-7, 86 NRC at 124.

496 Tr. at 417-18.

2.145 C-10 attempted to enlarge the scope of the admitted contention by pointing out that the ASR expansion monitoring program refers to the structure deformation monitoring program. Specifically, Dr. Saouma pointed out that Table 5 of the LAR provides that the recommended actions for Tier 3 structures, those with in-plane expansion of 0.1%, are enhanced ASR monitoring and a [s]tructural evaluation. 497 This, though, does not, as Dr.

Saouma claims, make the process used in the structure deformation monitoring program an integral part of ASR expansion monitoring; 498 rather, the term [s]tructural evaluation is simply a pointer for the Seabrook staff to initiate a process or evaluation separate from the ASR expansion monitoring program. 499 Stated another way, when in-plane expansion reaches 0.1%,

the ASR expansion monitoring program triggers two follow-on actions(1) implementing enhanced ASR monitoring under the ASR expansion monitoring program (i.e., installing an SRBE to measure through-thickness expansion) and (2) initiating a structural evaluation. 500 This [s]tructural evaluation may follow the separate process described in Sections 3.3 and 3.5.2 of the LAR and summarized in the separate Table 6 of the LAR. 501 Thus, the [s]tructural assessment under the structure deformation monitoring program may be triggered by the ASR expansion monitoring program, but it is not a part of the ASR expansion monitoring program. 502 2.146 Dr. Saouma also tried to conflate the two programs by noting that Section 3.5.2 of the LAR is titled Structure Deformation and not [S]tructure [D]eformation Monitoring, 503 but 497 Exhibit INT010-00-BD01, Original LAR at 33 of 73 (unnumbered); Exhibit INT001-R-00-BD01 at 24.

498 Exhibit INT001-R-00-BD01 at 24.

499 Exhibit NRC001-R-00-BD01, Staff Testimony at 66.

500 Id.

501 Id.; see Exhibit INT010-00-BD01, Original LAR at 34 of 73 (unnumbered).

502 Exhibit NRC001-R-00-BD01, Staff Testimony at 66-67.

503 Exhibit INT001-R-00-BD01 at 23.

this does not somehow mean that Section 3.5.2 is a part of the ASR expansion monitoring program. 504 On the contrary, a plain language reading of the LAR indicates that Section 3.5.2 has to do with only the structure deformation monitoring program and not the ASR expansion monitoring programSection 3.5 is titled Monitoring and it is broken up into Section 3.5.1, ASR Expansion [Monitoring], and Section 3.5.2, Structure Deformation [Monitoring]. 505 2.147 Based on the foregoing, we find that C-10s arguments regarding NextEras implementation of the structure deformation monitoring program are not within the scope of this proceeding.

H. Board Findings on NextEras Implementation of the Structure Deformation Monitoring Program 2.148 We find that, even if we were to consider C-10s out-of-scope challenges to the structure deformation monitoring program, C-10 has not shown any reason to question the adequacy of the program. First, C-10s arguments are based on Simpson, Gumpertz, & Heger, Inc., Evaluation and Design Confirmation of As-Deformed CEB, 150252-CA-02, Revision 0, July 2016; 506 whereas, the LAR was based on a substantially revised version of this report (i.e.,

Revision 2). 507 Second, as explained in detail below, C-10s individual arguments regarding the implementation of the structure deformation monitoring program are not persuasive.

504 Exhibit NRC001-R-00-BD01, Staff Testimony at 66-67.

505 Id.; Exhibit INT010-00-BD01, Original LAR at 30, 31, 33 of 73 (unnumbered).

506 Exhibit INT001-R-00-BD01 at 24-28; see Exhibit INT015-00-BD01, Simpson Gumpertz & Heger, Inc.,

Evaluation and Design Confirmation of As-Deformed CEB, 150252-CA-02, Rev. 0, July 2016 (Seabrook FP#100985) Enclosure 2 to Letter SBK-L-16153, re: Seabrook Station (Sept. 30, 2016) (ML19162A255).

507 Exhibit NRC001-R-00-BD01, Staff Testimony at 67.

a. Board Findings on the Use of Linear Elastic Analysis 2.149 C-10 argued that ASR and its impact at Seabrook cannot be analyzed using linear elastic methods. 508 Linear elastic methods, also referred to as linear, elastic behavior by NextEra, is when the deformation of the concrete increases proportionately to the load. 509 As NextEras expert witnesses explained, linear, elastic behavior is when the load-deformation relationship is a straight-line, or linear. 510 2.150 C-10 expert witness Dr. Saouma, however, argued that a safety assessment of Seabrook concrete can only be performed through a nonlinear analysis. 511 Dr. Saouma testified that [i]n analyzing the safety of existing safety structures, one has to determine the exact nonlinear response beyond the elastic limit because, according to Dr. Saouma, linear elastic analysis will under-estimate the displacements and cannot capture either the failure load or the deformation. 512 Non-linear behavior is when the structure deformation increases faster than the load increases. As NextEras expert witnesses stated, [t]he point at which the behavior becomes nonlinear in reinforced concrete corresponds to the onset of yielding of the reinforcement steel accompanied by increased cracking of the concrete. 513 2.151 NextEras use of linear elastic methods is grounded in the Seabrook design basis codes, sometimes referred to as codes of record, as documented in the Seabrook Updated Final Safety Analysis Report (UFSAR). 514 For Seabrook seismic Category I structures other 508 Exhibit INT001-R-00-BD01 at 24-26, 31-32 36; see Exhibit INT028-00-BD01 at 42.

509 Exhibit NER004-00-BD01, Testimony of NextEra Witnesses Said Bolourchi, Glenn Bell, and Matthew Sherman at 53 (ML19205A501) (SGH Testimony).

510 Id. at 52.

511 Exhibit INT001-R-00-BD01 at 7.

512 Id.

513 Exhibit NER004-00-BD01, SGH Testimony at 53.

514 Exhibit NRC001-00-BD01 at 68; Exhibit NER004-00-BD01, SGH Testimony at 51-56; see Exhibit INT024-00-BD01, SE at 48 (As required by the structural design in the Seabrook UFSAR Sections

than containment, the code of record is ACI 318-71. 515 The code of record for containment is ASME Code,Section III, Division 2. 516 Both codes employ linear, elastic methods. 517 2.152 In criticizing NextEras reliance on linear elastic methods, Dr. Saouma acknowledged that the assumption that the response up to failure will be linear is indeed code-driven. 518 Therefore, the parties agree that NextEras use of linear elastic methods is consistent with the design basis codes for Seabrook. 519 2.153 NextEra argued that the results of the LSTP justify NextEras continued reliance on the design basis codes and, therefore, linear elastic analysis. 520 As NextEra expert witness Mr. Bell testified, [t]he original codes of records were based on linear elastic analysis and so the entire evaluation that we did assuredis to assure that everything stays within the design limits using the original codes and equations and the approaches to analysis therein. 521 2.154 The Staff expert witnesses testified that the LSTP data support NextEras continued reliance on the design basis codes because the load-deformation plots of the LSTP 3.8.4.3 and 3.8.4.5 (corresponding UFSAR subsections for containment internal structures are 3.8.3.3 and 3.8.3.5), stresses and strains in the structures shall be maintained within elastic limits under normal operating (service) load conditions.); see also, e.g., Tr. at 303, 577-79, 853, 857-859, 865, 897, 923, 946 (referring to the design basis codes as the codes of record).

515 Exhibit NRC001-R-00-BD01 at 68; see Exhibit NRC049-00-BD01, American Concrete Institute (ACI)

Standard 318-71, Building Code Requirements for Reinforced Concrete (1971) (ML19205A479) (Non-publicly available).

516 Exhibit NRC001-00-BD01 at 68; see Exhibit NRC050-00-BD01,Section III, Division 2, of the 1975 Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for Containment (ML19205A480) (Non-publicly available).

517 Exhibit NER004-00-BD01, SGH Testimony at 52.

518 Exhibit INT001-R-00-BD01 at 7; see Exhibit INT028-00-BD01 at 3-4.

519 See, e.g., Exhibit INT001-R-00-BD01 at 7; Exhibit NER004-00-BD01, SGH Testimony at 52; Exhibit NRC001-R-00-BD01 at 68-69.

520 See, e.g., Tr. at 973 ([The] LSTP confirmed that the code equations are valid.) (Mr. Bolourchi);

Exhibit NER004-00-BD01, SGH Testimony at 57.

521 Tr. at 303; see Tr. at 857-859.

specimens that were tested to failure generally showed linear behavior up to the point of flexural yielding (in the Reinforcement Anchorage Test Program) or initiation of the diagonal crack (in the Shear Test Program) similar to the behavior of the control specimens and the assumptions in the code. 522 Therefore, the LSTP results indicated that the behavior of Seabrook ASR-affected structures may be considered to be bounded by original design methods, that is, that the code equations provide a lower bound estimate of structural capacity of Seabrook ASR-affected concrete members. 523 The Staffs expert witnesses also pointed out that NextEras conclusion on the continued applicability of the codes of record is consistent with those made based on large-scale testing by other researchers. 524 2.155 NextEra and the Staff argued that the non-linear analysis advocated by Dr.

Saouma would require a complete departure from Seabrooks design basis codes. 525 And, indeed, Dr. Saouma repeatedly criticized NextEras and the Staffs reliance on the design basis codes. 526 At bottom, Dr. Saouma took issue with NextEras entire analytical approach with the LSTP, which was to determine whether the design basis codes still applied, notwithstanding the 522 Id.; see Exhibit INT020-00-BD01, MPR-4253, ASR Monitoring Report (Rev. 3), fig. 5-5 at 5-7, fig. 5-7 at 5-11 (Non-publicly available); Tr. at 1055-58, 1083-88.

523 Exhibit NRC001-R-00-BD01, Staff Testimony at 68.

524 Id.; see Exhibit NRC074-00-BD01, Stéphane Multon, et. al., Flexural Strength of Beams Affected by ASR, 12th International Conference on Alkali-Aggregate Reaction, Beijing, China (2004) at § 6 (ML19205A475); Exhibit NRC075-00-BD01, Dean J., Deschenes, et. al., ASR/DEF-Damaged Bent Caps:

Shear Tests and Field Implications, Technical Report No. 12-8XXIA006 summarizing work conducted for the Texas Department of Transportation at Ferguson Structural Engineering Laboratory, The University of Texas at Austin (August 2009) at 226 (ML19205A441).

525 See, e.g., Tr. at 852-53; Exhibit NER001-00-BD01, MPR Testimony at 132-33 ([T]he non-linear analysis [advocated by Dr. Saouma] would be a complete departure from the ACI and ASME Codes that form the design basis for Seabrook.); Exhibit NER004-00-BD01, SGH Testimony at 47, 46.

526 See, e.g., Exhibit INT001-R-00-BD01 at 30-31; Exhibit INT028-00-BD01 at 3-4; Tr. at 301 (We cannot assume a factor of safety embedded in the ACI code. We have to determine the factor of safety ourself.); Tr. at 342 (This problem is way too complex to limit its solution to a mere satisfaction of a design code.); Tr. at 863 (We are dealing with a structure where we cannot afford the luxury of relying on the simplistic approach of the ACI code.).

presence of ASR. 527 According to Dr. Saouma, the very fact that the codes do not account for ASR renders them wholly outdated and unreliable. 528 Instead, to address the complexity of ASR at Seabrook, Dr. Saouma testified that NextEra has to go beyond the existing code. 529 2.156 NextEras expert witnesses, however, testified that the LSTP confirmed the continued applicability of the codes of record to ASR-affected concrete structures at Seabrook.

NextEras use of a linear elastic analysis, consistent with those codes, in its structure deformation monitoring program is conservative. 530 NextEras witnesses explained that, contrary to Dr. Saouma general criticisms of the codes, the codes of record generally limit the stresses and strains to conservative levels. 531 Thus, a nonlinear analysis that would extrapolate the point at which the structure would fail is inapplicable because the codes of record limit the stresses and deformations to below yield levels. 532 2.157 The Staff expert witnesses also made clear that if Seabrook ever approached or exceeded the limits of its codes of record, NextEra would be in the same position that it had faced when it first discovered the presence of ASR at SeabrookNextEra would have to 527 See e.g., Tr. at 311, 342, 385, 574, 576, 988.

528 See, e.g., Exhibit INT028-00-BD01 at 4 (describing one of the codes of record as an outdated and flawed tool); Tr. at 311, 952, 988 1065-66; see also Tr. at 385 (If you want to restrict ourselves only to code, there is very little we can do to assess the safety of the structure. We might as well close it immediately. We have to go beyond that to make sure that it is operational, safety operational, and we know whether it is safety operational.); Tr. at 574 (We're dealing with an extra identity problem here, which requires to think a little bit outside the envelope and the envelope being those existing codes.

Those codes were not written for a structure like this one, which is suffering from ASR. So we have to broaden our mind a little bit.); Tr. at 576 (Dr. Saouma challenging the applicability of the 1971 ASME code to Seabrook).

529 Tr. at 988.

530 Id. at 857-860 (Mr. Bell).

531 Id. at 857.

532 Id. at 857-860 (Mr. Bell).

perform prompt operability determinations and, ultimately, come into compliance with its licensing basis or seek approval for a license amendment. 533 2.158 Moreover, the Staff testified that selecting a methodology that would require a wholesale departure from Seabrooks licensing basis, as Dr. Saouma advocated, would be difficult to justify in light of the NRCs overall licensing framework. 534 As Staff expert witness Ms.

Buford explained, it was reasonable to the staff for the applicant to use [an LSTP] because the purpose of that was to verify that the applicant was going to be able to use their codes of record rather than throw out the codes of record, and develop a new approach. [The Staff]

found that very reasonable since this is the regulatory framework that theyre designed and licensed to, as opposed to taking an experimental approach that the [S]taff has not, approved or considered [and] that would go beyond or throw out the licensing basis, the ACI 318 codes. 535 2.159 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the use of linear elastic analysis is appropriate to NextEras codes-based approach.

533 Tr. at 739-40, 946, 1025-26.

534 See Tr. at 574 (T]he burden on the licensee and what [the Staff is] reviewing is that the structures are required to remain operable. And they are required to continue to stay within their design and licensing bases. And so what the licensee opted to do to demonstrate that the design codes and licensing basis remains intact was the charge of the staff to review. So looking beyond the codes is outside of the scope of the requirement for the structures to remain operable and to stay within the bounds of their licensing basis.); see also Exhibit NER004-00-BD01, SGH Testimony at 56 (In other words, to comply with Seabrooks licensing basis, loads, analytical techniques, and determination of performance against acceptability criteria all go hand-in-hand and must be in accordance with the codes and standards detailed in the UFSAR that form the licensing basis for Seabrook. Thus, the non-linear analysis Dr.

Saouma demands is not applicable or relevant to structural behavior at Seabrook.).

535 Id. at 852-53; see also id. at 859 ([T]he desire to tie back to the codes of record through the design basis is the methodology that is always the first choice here, and that's what we've done.) (Mr. Bell); id.

at 947 ([W]hen we went outside the bounds of our design bases, that requires prior approval from the Commission. And thats what we did with the license amendment request. We would never go outside of our licensing bases to evaluate a problem and use that for real plant modifications or analysis unless its been prior approved by the Commission via a license amendment request.) (Mr. Collins).

b. Board Findings on the Potential for NextEra to Use a Probabilistic-Based Analysis Instead of its Codes-Based Approach 2.160 C-10 argued that a probabilistic-based analysis should be performed for the Seabrook structural evaluation because of the high risks associated with an accident at Seabrook and the uncertainties associated with capacity and demand. 536 Specifically, C-10 expert witness Dr. Saouma advocated for the use of a structural assessment model that accounts for uncertainties. 537 Dr. Saouma conceded, however, that this would be outside the scope of the proceeding 538 and stated that, yes, I am also aware that this is not required. 539 Nevertheless, he insisted that the best approach, the most intelligent approach, is to say be humble, recognize that we do not have everything known. 540 2.161 As recognized at the evidentiary hearing by Judge Trikouros, a probabilistic-based analysis is not required for this LAR. 541 NextEra expert witness Mr. Bell testified that (1) a probabilistic-based analysis is not necessary because Seabrook is staying within its design basis and (2) a probabilistic-based approach is just not practical in this context. 542 The claim that a probabilistic-based analysis could have been performed instead of the approach proposed in the LAR is also not relevant to the NRC review of the LAR. The Staff found that NextEras proposed codes-based approach provided reasonable assurance that the ASR-536 Exhibit INT001-R-00-BD01 at 29.

537 Tr. at 810.

538 Id. at 811.

539 Id. at 813.

540 Id. at 812-13.

541 Id. at 810-11 ([Y]ou understand that that is not required in licensing space for Seabrook or any plant?) (Judge Trikouros); see also id. at 815 ([P]robabilistic risk assessments are not part of the licensing requirement here. They are generally done, as has been stated, when the design basis has been exceeded and its necessary to understand the implications of that. That isnt the purpose of what were doing here.) (Mr. Bell).

542 Id. at 815-16.

affected structures at Seabrook remain capable of performing their intended safety functions. 543 Therefore, C-10s assertion that a better approach is available, without more, is not relevant to this proceeding. 544 2.162 Based on the foregoing, we find that NextEra has demonstrated by a preponderance of the evidence that the potential for NextEra to use a probabilistic-based analysis instead of its codes-based approach is not relevant.

III. CONCLUSIONS OF LAW 3.1 With respect to the admitted contention, the Board has considered all the filings in this proceeding, the exhibits received in evidence, and the transcript of the evidentiary hearing. Based on its review of the record, the proposed findings of fact and conclusions of law submitted by the parties, and the findings of fact set forth above, which are supported by reliable, probative, and substantial evidence in the record, the Board has decided all matters in controversy concerning this contention in favor of NextEra and reaches the following conclusions of law.

3.2 Under 10 C.F.R. § 50.90, whenever a holder of a license wishes to amend its license, including technical specifications in the license, an application for amendment must be filed with the NRC. Under 10 C.F.R. § 50.92(a), the NRC is guided by the considerations that govern the issuance of initial operating licenses, to the extent applicable and appropriate, in determining whether to grant an amendment to an operating license. In turn, both the common standards for construction permits and operating licenses in 10 C.F.R. § 50.40(a), and those specifically for issuance of operating licenses in 10 C.F.R. § 50.57(a)(3), provide that there must be reasonable assurance that the activities at issue will comply with the regulations and can be conducted without endangering the health and safety of the public. As the Commission has 543 Exhibit NRC001-R-00-BD01, Staff Testimony at 71.

544 Id.

stated, [a] license amendment request must provide sufficient documentation and analysis to show that the licensee has complied with the relevant requirements, thereby demonstrating that the amended license will continue to provide reasonable assurance of adequate protection of public health and safety. 545 3.3 Seabrook UFSAR Section 3.1, Conformance to NRC General Design Criteria, discusses the extent to which the design criteria for Seabrook structures, systems, and components important to safety meet the NRC General Design Criteria for Nuclear Power Plants, specified in 10 C.F.R. Part 50, Appendix A (GDC). 546 3.4 The GDC that are applicable to the UFSAR changes proposed in the LAR are GDC 1 (Quality Standards and Records), 547 2 (Design Bases for Protection Against Natural Phenomena), 548 4 (Environmental and Missile Design Bases), 549 16 (Containment Design), 550 and 50 (Containment Design Basis). 551 Of these, GDC 1, 2, and 4 apply to all Seabrook seismic Category I structures, including containment; GDC 16 and 50 apply only to containment. 552 In relevant part, these GDCs state as follows:

Criterion 1Quality standards and records. Structures, systems, and components important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed.

545 Entergy Nuclear Operations, Inc. (Palisades Nuclear Plant), CLI-15-22, 82 NRC 310, 316 (2015).

546 Exhibit NRC007-00-BD01, UFSAR § 3.1; see 10 C.F.R. Part 50, App. A.

547 Id. § 3.1.1.1 at 1-2; see Exhibit INT024-00-BD01, SE, encl. 2 at 2; Exhibit INT010-00-BD01, Original LAR at 35 of 73 (unnumbered).

548 Exhibit NRC007-00-BD01, UFSAR § 3.1.1.2 at 2-3; see Exhibit INT024-00-BD01, SE, encl. 2 at 2; Exhibit INT010, Original LAR at 35 of 73 (unnumbered).

549 Exhibit NRC007-00-BD01, UFSAR § 3.1.1.4 at 3-4; see Exhibit INT024-00-BD01, SE, encl. 2 at 2; Exhibit INT010-00-BD01, Original LAR at 35 of 73 (unnumbered).

550 Exhibit NRC007-00-BD01, UFSAR § 3.1.2.7 at 8-9; see Exhibit INT024-00-BD01, SE, encl. 2 at 2; Exhibit INT010-00-BD01, Original LAR at 35 of 73 (unnumbered).

551 Exhibit NRC007-00-BD01, UFSAR § 3.1.5.1 at 29-30; see Exhibit INT024-00-BD01, SE, encl. 2 at 2; Exhibit INT010-00-BD01, Original LAR at 35 of 73 (unnumbered).

552 Exhibit INT024-00-BD01, SE, encl. 2 at 2.

Where generally recognized codes and standards are used, they shall be identified and evaluated to determine their applicability, adequacy, and sufficiency and shall be supplemented or modified as necessary to assure a quality product in keeping with the required safety function. A quality assurance program shall be established and implemented in order to provide adequate assurance that these structures, systems, and components will satisfactorily perform their safety functions.

Criterion 2Design bases for protection against natural phenomena. Structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions. The design bases for these structures, systems, and components shall reflect: (1) Appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated, (2) appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena and (3) the importance of the safety functions to be performed.

Criterion 4Environmental and dynamic effects design bases. Structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents.

These structures, systems, and components shall be appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that may result from equipment failures and from events and conditions outside the nuclear power unit.

Criterion 16Containment design. Reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require.

Criterion 50Containment design basis. The reactor containment structure, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any loss-of-coolant accident.

3.5 In addition, Appendix B to 10 C.F.R. Part 50 establishes quality assurance requirements for the design, manufacture, construction, and operation of structures, systems, and components that prevent or mitigate the consequences of postulated accidents that could

cause undue risk to the health and safety of the public. 553 Activities related to the changes proposed in the LAR include procurement control measures on purchased materials, equipment, services, and design control measures. 554 Section Ill, Design Control, of Appendix B to 10 C.F.R. Part 50, requires that the design control measures be established to ensure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. 555 These measures must include provisions to ensure that appropriate quality standards are specified and included in design documents and that deviations from such standards are controlled. 556 Design changes, including field changes, must be subject to design control measures commensurate with those applied to the original design. 557 3.6 In this proceeding, NextEra carries the burden of proof on whether there is reasonable assurance that operation in the manner proposed by the LAR will comply with applicable regulations and will not endanger the health and safety of the public. 558 The Commission has cautioned that [r]easonable assurance is not quantified as equivalent to a 95% (or any other percent) confidence level, but is based on sound technical judgment of the particulars of a case and on compliance with our regulations. 559 To satisfy this reasonable assurance standard, NextEra must make a showing that meets the preponderance of the 553 10 C.F.R. Part 50, Appendix B.

554 Exhibit INT024-00-BD01, SE, encl. 2 at 5.

555 10 C.F.R. Part 50, Appendix B § III.

556 Id.

557 Id.

558 See 10 C.F.R. § 2.325; Duke Power Co. (Catawba Nuclear Station, Units 1 and 2), CLI-83-19, 17 NRC 1041, 1048 (1983) (citing Consumers Power Co. (Midland Plant, Units 1 and 2), ALAB-283, 2 NRC 11, 17 (1975)).

559 AmerGen Energy Co., LLC (Oyster Creek Nuclear Generating Station), CLI-09-7, 69 NRC 235, 262-63 (2009).

evidence threshold of compliance with the applicable regulations. 560 As indicated above, the applicable regulations in this proceeding are GDC 1, 2, 4, 16, and 50 and Appendix B to 10 C.F.R. Part 50. 561 3.7 After full consideration for all of C-10s arguments, the facts in this proceeding show that NextEra has demonstrated, by a preponderance of the evidence, reasonable assurance that, with activities authorized by the approval of the LAR, Seabrook will continue to meet GDC 1, 2, 4, 16, and 50 and Appendix B to 10 C.F.R. Part 50 without endangering the health and safety of the public.

Respectfully submitted,

/Signed (electronically) by/

Jeremy L. Wachutka Counsel for the NRC Staff U.S. Nuclear Regulatory Commission Mail Stop O14-A44 Washington, DC 20555 Telephone: (301) 287-9188 E-mail: Jeremy.Wachutka@nrc.gov Executed in Accord with 10 CFR 2.304(d)

Jennifer E. Scro Counsel for the NRC Staff U.S. Nuclear Regulatory Commission Mail Stop O14-A44 Washington, DC 20555 Dated at Rockville, Maryland Telephone: (301) 287-9081 this 21st day of November 2019 E-mail: Jennifer.Scro@nrc.gov 560 Id.; see Pac. Gas & Elec. Co. (Diablo Canyon Nuclear Power Plant, Units 1 and 2), ALAB-763, 19 NRC 571, 577 (1984) (to prevail on factual issues, the applicants position must be supported by a preponderance of the evidence); Tennessee Valley Authority (Hartsville Nuclear Plant, Units 1A, 2A, 1B, and 2B), ALAB-463, 7 NRC 341, 360 (1978), reconsideration denied, ALAB-467, 7 NRC 459 (1978)

(Absent some special statutory standard of proof, factual issues are determined by a preponderance of the evidence.).

561 Although in this proceeding the Staff has issued the challenged license amendment prior to the hearing, this does not shift the burden of proof; the burden remains on NextEra. See Crow Butte Res.,

Inc. (In Situ Leach Facility, Crawford, Nebraska), CLI-15-17, 82 NRC 33, 41 (2015) (stating that the issuance of a materials renewal license where a hearing was pending did not shift the burden of proof because regardless of the issuance of the license, the burden remains on the applicant, and, with respect to NEPA compliance, on the Staff).

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of NEXTERA ENERGY SEABROOK, LLC Docket No. 50-443-LA-2 (Seabrook Station, Unit 1)

CERTIFICATE OF SERVICE Pursuant to 10 C.F.R. § 2.305, I hereby certify that copies of the foregoing NRC STAFF PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW FOR THE ADMITTED CONTENTION, dated November 21, 2019, have been filed through the Electronic Information Exchange, the NRCs E-Filing System, in the above-captioned proceeding, this 21st day of November 2019.

/Signed (electronically) by/

Jeremy L. Wachutka Counsel for the NRC Staff U.S. Nuclear Regulatory Commission Mail Stop O14-A44 Washington, DC 20555 Telephone: (301) 287-9188 E-mail: Jeremy.Wachutka@nrc.gov