ML19325F390

NextEra Energy Seabrook LLCs Proposed Findings of Fact and Conclusions of Law

ML19325F390
Person / Time
Site:	Seabrook
Issue date:	11/21/2019
From:	Bessette P, Hamrick S, Lighty R Morgan, Morgan, Lewis & Bockius, LLP, NextEra Energy Seabrook
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
50-443-LA-2, ASLBP 17-953-02-LA-BD01, RAS 55423
Download: ML19325F390 (120)

Text

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of:

NEXTERA ENERGY SEABROOK, LLC (Seabrook Station Unit 1)

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Docket No. 50-443-LA-2 November 21, 2019 NEXTERA ENERGY SEABROOK LLCS PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW Steven Hamrick, Esq.

NextEra Energy Seabrook, LLC 801 Pennsylvania Ave., NW Suite 220 Washington, D.C. 20004 Phone: (202) 349-3496 Fax: (202) 347-7076 E-mail: steven.hamrick@fpl.com Paul M. Bessette, Esq.

Ryan K. Lighty, Esq.

Morgan, Lewis & Bockius LLP 1111 Pennsylvania Avenue, NW Washington, D.C. 20004 Phone: (202) 739-5796 Fax: (202) 739-3001 E-mail: paul.bessette@morganlewis.com E-mail: ryan.lighty@morganlewis.com Counsel for NextEra Energy Seabrook, LLC

TABLE OF CONTENTS I.

INTRODUCTION AND

SUMMARY

OF FINDINGS.......................................................... 1 II. HISTORY OF THE PROCEEDING....................................................................................... 5 III. APPLICABLE LEGAL AND REGULATORY STANDARDS.......................................... 19 A. License Amendment Standards...................................................................................... 19 B. The Reasonable Assurance Standard.............................................................................. 19 C. Burden of Proof.............................................................................................................. 21 D. Scope of Contentions and Motions in Limine................................................................ 22 IV. FACTUAL FINDINGS AND LEGAL CONCLUSIONS.................................................... 24 A. Witnesses........................................................................................................................ 25 (1) NextEras Expert Witnesses.................................................................................... 25 (2) NRC Staffs Expert Witnesses................................................................................ 29 (3) C-10s Expert Witness............................................................................................ 31 B. Technical Background on ASR and Structural Adequacy............................................. 33 C. Motions in Limine........................................................................................................... 35 (1) Previously-Rejected Arguments and Extraneous Topics........................................ 36 (2) New Challenges to the LSTP.................................................................................. 40 (3) New Challenges Regarding Seabrook Structural Evaluations................................ 42 (4) Impermissible Rebuttal........................................................................................... 44 D. The LSTP........................................................................................................................ 45 (1) Concrete Mixture Design........................................................................................ 52 (2) Specimen Scale and Reinforcement Configuration................................................ 59 (3) Experimental Design............................................................................................... 63 E. The SMP......................................................................................................................... 67 (1) SMP ASR Expansion Monitoring Techniques........................................................ 70 a.

In-Plane Expansion.......................................................................................... 71 b.

Through-Thickness Expansion........................................................................ 75 c.

Volumetric Expansion...................................................................................... 81 d.

Other Monitoring Techniques.......................................................................... 81 (2) SMP ASR Expansion Acceptance Criteria............................................................. 84 (3) SMP ASR Expansion Inspection Intervals.............................................................. 86

2 F. The SEM......................................................................................................................... 91 (1) Individual Structural Evaluations............................................................................ 94 (2) Original Design Capacities...................................................................................... 97 (3) ASR Loads and Load Factors.................................................................................. 99 (4) Code-Based Structural Evaluation Approach....................................................... 101 (5) Criticisms Specific to the Rev. 0 CEB Evaluation................................................ 105 a.

Thermal Expansion & Shell Elements........................................................... 105 b.

Bubble Expansion.......................................................................................... 108 c.

Steel Membrane Elements.............................................................................. 109 d.

Swelling......................................................................................................... 109 e.

Seismic Analysis............................................................................................ 110 f.

Section Cut Approach.................................................................................... 112 V.

SUMMARY

FINDINGS OF FACT AND CONCLUSIONS OF LAW............................. 113 VI. ORDER................................................................................................................................ 115

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of:

NEXTERA ENERGY SEABROOK, LLC (Seabrook Station Unit 1)

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Docket No. 50-443-LA-2 November 21, 2019 NEXTERA ENERGY SEABROOK LLCS PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW Pursuant to 10 C.F.R. § 2.1209, and the Atomic Safety and Licensing Boards (Board) oral instructions at the evidentiary hearing,1 NextEra Energy Seabrook, LLC (NextEra) submits its Proposed Findings of Fact and Conclusions of Law (FOF/COL) regarding C-10 Research and Education Foundation, Inc.s (C-10) Contention, as admitted by the Board in LBP-17-7. The FOF/COL are based on the evidentiary record in this proceeding, and are submitted in the form of a proposed Initial Decision by the Board. The FOF/COL are set out in numbered paragraphs beginning in the next section, with corresponding citations to the record of this proceeding.

I.

INTRODUCTION AND

SUMMARY

OF FINDINGS

1.

This Initial Decision presents the Boards Findings of Fact and Conclusions of Law on C-10s sole Contention. As admitted by the Board, the Contention is a safety contention asserting that [t]he large-scale test program [or LSTP], undertaken for NextEra at the [Ferguson Structural Engineering Laboratory or] FSEL, has yielded data that are not representative of the 1

Official Transcript of Proceedings, Docket No. 50-442-LA-2 at 1181-82 (Tr.); see also generally ASLB Order (Adopting Transcript Corrections, Transcript Redactions, and Final Exhibit List), App. A (Oct. 29, 2019) (Tr. Corr.).

2 progression of [Alkali-Silica Reaction or] ASR at Seabrook [Station Unit 1]. As a result, the proposed monitoring, acceptance criteria, and inspection intervals are not adequate.2 More specifically, C-10 claims that NextEras License Amendment Request 16-03 (LAR) is deficient because the LSTP did not replicate certain allegedly-unique aging and environmental exposure-related aspects of Seabrooks concrete; and that as a result of this alleged non-representativeness, crack width indexing and extensometer deployment are not sufficient tools for determining the extent and progression of ASR, further core sampling and testing are required to adequately monitor ASR progression, and the expansion monitoring intervals allegedly are too long.3

2.

As a threshold matter, the Board finds that C-10 has failed to meet its initial burden of moving forward with sufficient evidence on the Contention as pled and admitted. As discussed in further detail below, the key issue in the Contention is C-10s claim that the concrete in the LSTP test specimens was not representative of the concrete at Seabrook because the plants concrete had aged and been exposed to various environmental conditions such as salt water, heat, and radiation. However, C-10s hearing evidence (supported by their current expert witness, Dr. Saouma) materially departs from C-10s original claims (which were supported by historical comment letters from a different expert, Dr. Brown). In summary, C-10s hearing evidence purports to challenge the LAR on numerous other groundsbut not the ones pled in the original Contentionand thus is not probative of the Contention as pled and 2

NextEra Energy Seabrook LLC (Seabrook Station Unit 1), LBP-17-7, 86 NRC 59, 90 (2017), affd CLI-18-4, 87 NRC 89 (2018).

3 See generally C-10 Research and Education Foundation, Inc., Petition for Leave to Intervene at 2 (Apr. 10, 2017) (ML17100B013) (Petition) (contentions A, B, C, D, and H).

3 admitted, and fails to satisfy the prima facie threshold for those original arguments (which its evidence does not address).

3.

Nevertheless, even if C-10 had satisfied its initial burden of going forward on the Contention, we conclude 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, to the extent necessary to provide reasonable assurance regarding NextEras ability to evaluate the structural adequacy of Seabrooks seismic Category I structures. We further find that the preponderance of the evidence demonstrates that NextEras proposed monitoring, acceptance criteria, and inspection intervals are adequate to provide reasonable assurance.

4.

Overall, we find that a preponderance of the evidence supports the NRC Staffs conclusion that the LARs plant-specific method of evaluation for seismic Category I reinforced concrete structures affected by ASR at Seabrook is acceptable and provides reasonable assurance that these structures continue to meet the relevant requirements of 10 CFR Part 50, Appendix A, General Design Criteria (GDC) 1, 2, 4, 16 and 50, and 10 CFR Part 50, Appendix B; and that NextEra has satisfied the requirements of 10 C.F.R. §§ 50.92 and 50.57(a)(3) and (6).

5.

Furthermore, for the reasons set forth below, the Board finds that the LAR is based on sound science, the current state of established knowledge of ASR development and progression at Seabrook, and well-established structural engineering principles. It is also fully compliant with the long-established industry codes (which themselves incorporate inherent margins of safety) and Nuclear Regulatory Commission (NRC) regulations applicable to domestic operating nuclear plants. The Board acknowledges that ASR is a developing field of scientific and engineering research. However, as further explained below, the Board finds the preponderance of the evidence collectively demonstrates that, among other things, the LSTP

4 yielded data that are appropriate for use in the LAR, the Structures Monitoring Program (SMP) is adequate for monitoring Seabrooks ASR, and the Structural Evaluation Methodology (SEM) is adequate for analyzing the structural adequacy of Seabrooks seismic Category I structures, and thus the LAR provides the requisite reasonable assurance for the NRC Staff to issue the requested amendment.

6.

Our conclusions are informed by hundreds of pages of written testimony, a transcript of oral testimony that is over a thousand pages, and many thousands of pages of exhibits. Our specific findings and conclusions are detailed in the sections below. However, our decision is guided at least partially by a few high-level observations.

7.

First, the LAR uses a classic aging management approach, long endorsed by the NRC to monitor various degradation mechanisms. This approach has been proven to adequately manage degradation mechanisms regardless of extent or rate of degradation because they monitor actual progression rather than attempt to predict it, so long as the monitoring intervals are appropriate.4 As detailed below, we have determined that NextEras monitoring intervals are, in fact, appropriate. In practical terms, after more than 30 years of ASR propagation in Seabrooks structures, it has reached only low to moderate levels and has been referred to as slow.5 But even if that rate changes, the LARs aging management approach ensures ASR will be adequately managed.

8.

Second, the LAR is firmly rooted in structural engineering concepts that are fully compatible with Seabrooks existing licensing basis and that leverage industry consensus codes 4

Testimony of NextEra Witnesses Michael Collins, John Simons, Christopher Bagley, Oguzhan Bayrak, and Edward Carley at A220, A229 (July 24, 2019) (MPR Testimony) (NER001).

5 Testimony of NextEra Witnesses Said Bolourchi, Glenn Bell, and Matthew Sherman at A90 (July 24, 2019)

(SGH Testimony) (NER004).

5 that (1) already have embedded conservatisms to address potential uncertainty and (2) utilize acceptance criteria proven to be conservative and appropriate over many decades of real world structural performance experience. The record indicates that NextEra could have started from scratch with theoretical research, including probabilistic methods that attempt to predict (rather than monitor, in the classic sense) the progression of ASR. However, there are no NRC or broader industry consensus standards for such an approach, and no time-tested acceptance criteria. Furthermore, it is not at all clear how such an approach would be consistent with Seabrooks design and licensing basis or NRC regulations.6 On balance, we find NextEras approach eminently reasonable given the current state of ASR knowledge and NextEras need to analyze the structures at its operating power plant now. Moreover, NextEra is legally obligated to continuously monitor the state of ASR knowledge going forward, and to take appropriate action (subject to NRC oversight and enforcement) if it discovers information that would call into question the approach in the LAR.

9.

Accordingly, NextEra has fully met its burden of showing, by a preponderance of the evidence, that the Contention lacks merit. Thus, the Board enters a ruling on the merits in NextEras favor.

II.

HISTORY OF THE PROCEEDING

10.

NextEra first identified symptoms of ASR expansion at Seabrook in 2009 in the B Electrical Tunnel.7 Notably, at that time (and still to this day) there existed no specific NRC guidance, NRC regulations, or accepted nuclear industry standards for addressing ASR.8 6

See, e.g., Tr. at 1130 (Ms. Buford expressing doubt that such an approach could even be licensed by the NRC).

7 MPR Testimony at A76 (NER001).

8 See Tr. at 986-98 (discussing lack of guidance on ASR); see also id. at 986-87 (Dr. Saouma stating, [t]here is no guidance as of now for concrete with ASR.).

6 Various ASR-related research is currently being conducted by various researchers around the globe. But this research remains ongoing, and has not yielded any consensus method for addressing ASR in existing structures. As Dr. Souma and others have noted in various papers (prepared several years after ASR was first discovered at Seabrook), research on multiple proposed probabilistic and chemo-mechanical models is still in its early stages, and has not been reviewed (much less adopted) by any consensus body.9 And a presentation at the NRCs 2018 Regulatory Information Conference indicated that the National Institute of Standards and Technology is continuing to perform testing to support the NRCs eventual development of guidance on this topic.10 Thus, when ASR was discovered at Seabrookan operating nuclear power plantNextEra was left to develop its own program for managing ASR that was compatible with its existing licensing basis.

11.

Seabrooks original legal licensing basis, as described in its Updated Final Safety Analysis Report (UFSAR), includes methods for performing structural evaluations on Seabrooks Containment Building (Containment) and certain other structures (collectively known as seismic Category I structures) at the plant to ensure that they fulfill their design basis functions following a design basis earthquake.11 These methods correspond to the structural design codes in Seabrooks UFSARmore specifically, the ASME Boiler and Pressure Vessel Code Section III, Div. 2, 1975 (ASME 1975) (NRC050) for the Containment Building, and ACI Standard 318-71 (ACI 318-71) (NRC049) for all other seismic Category I structures at the plant.12 These codes, developed by consensus committees of leading structural engineering 9

MPR Testimony at A195 (NER001).

10 Id. at A60.

11 Id. at A31.

12 Id. at A31, A62.

7 experts, are NRC-approved, impose mandatory legal requirements on NextEra, and have been proven to contain safe and conservative structural analysis methods and acceptance criteria based on decades of actual experience around the world. Although ASR is not among the prescriptive (i.e., minimum) list of loads that must be considered, the codes permit the analysis and inclusion of additional loads, such as ASR, in the calculations.13

12.

Thus, NextEra submitted LAR 16-03 on August 1, 2016, seeking NRC approval to revise its UFSAR to incorporate a means of doing so (Original LAR Package).14 In addition to its structural engineering-based monitoring approach in the SMP, the LAR methodology also includes an analytical approach in the SEM for evaluating ASR-affected concrete structures using the original licensing basis design codes by accounting for the effects of ASR on design basis loads.15 In essence, NextEras approach was to develop an ASR supplement for use in Seabrooks existing codes, and to do so in a way that maintains the required level of structural performance and margin of safety implicit in the original design criteria, codes, and standards.16

13.

As discussed in relevant detail elsewhere in our decision, NextEra refined and revised the LAR several times during the course of the NRCs review. More specifically, NextEra supplemented its Original LAR Package on September 30, 2016 (LAR 13 Id. at A31. See also infra Part IV.F.(4).

14 Id. at A31. NextEra License Amendment Request (LAR) 16 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). The Original LAR Package included: NextEras Evaluation of the Proposed Change and Attach. 1 (Markup of UFSAR Pages) (Aug. 1, 2016) (LAR Evaluation) (INT010 (Proprietary (P)),

NRC089 (P) (non-highlighted proprietary version), INT010 (Non-Proprietary (NP))); MPR-4288, Rev. 0, Seabrook Station: Impact of Alkali-Silica Reaction on Structural Design Evaluations (July 2016) (MPR-4288) (INT014 (P), INT012 (NP)); MPR-4273, Rev. 0, Seabrook Station - Implications of Large Scale Test Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction (July 2016) (NRC009 (P),

NRC008 (NP)); and 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) (INT013).

15 MPR Testimony at A31 (NER001); see also LAR Evaluation (INT010 (NP), NRC089 (P)).

16 Id.

8 Supplement),17 and provided additional details and refinements to the proposed methodology in various responses to NRC requests for additional information (RAI) between October 2017 and June 2018 (collectively, the RAI Responses).18

14.

There are three key aspects of the LAR: the LSTP, the SMP, and the SEM.

15.

LSTP: Due to limitations in the published literature directly addressing the effects of ASR on structural adequacy,19 NextEra commissioned the LSTP in 2011 to supplement the available information20. The LSTP included extensive testing of specimens that sufficiently reflected the characteristics of ASR-affected structures at Seabrook.21 Tests were completed over the course of approximately four years22 at various levels of ASR development, including levels of ASR beyond that experienced at Seabrook to date, to assess the resulting impacts on structural performance.23 The LSTP found that, up to the levels of expansion observed in the testing, structural capacity was not degraded in ASR-affected concrete members.24 In fact, the 17 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 (SBK-L-16153) (Sept. 30, 2016). The LAR Supplement included: NextEras Supplement to LAR 16-03 (Sept. 30, 2016) (NRC010); SG&H, Evaluation and Design Confirmation of As-Deformed CEB, 150252-CA-02, Rev. 0 (July 2016) (Seabrook FP#100985) (Rev. 0 CEB Evaluation) (INT015); and MPR-4153, Rev. 2, Seabrook Station - Approach for Determining Through-Thickness Expansion form Alkali-Silica Reaction (July 2017) (this revision was not submitted as an exhibit, but Rev. 3 (Sept. 2017) was (INT020 (P),

INT018-R (NP)) (MPR-4153)).

18 Seabrook Station, Response to Request for Additional information Regarding License Amendment Request 16-03 Related to ASR (SBK-L-17156) (Oct. 3, 2017) (SBK-L-17156) (NRC013); Seabrook Station, Response to Request for Additional information Regarding License Amendment Request Related to ASR (SBK-L-17204) (Dec. 11, 2017) (SBK-L-17204) (NRC014); Seabrook Station, Response to Request for Additional information Regarding License Amendment Request 16-03 (SBK-L-18074) (June 7, 2018) (SBK-L-18074)

(NRC015) (collectively, along with their associated attachments, the RAI Responses).

19 MPR Testimony at A40 (NER001).

20 Id. at A99.

21 See infra Part IV.D.

22 Id. See also NRC Safety Evaluation Related to Amendment No. 159 to Facility Operating License No. NPF-86 at § 3.1.2 (Mar. 11, 2019) (Final SE) (INT024 (NP), INT025(P)).

23 MPR Testimony at A115 (NER001); MPR Testimony, Attach. 2, Proprietary Appendix, tbl.2 (NER003)

(Prop. Appx).

24 MPR Testimony at A91 (NER001).

9 testing showed that structural capacities were even greater than the capacities calculated using the plants original specified concrete material properties and relevant sections of applicable design codes.25 This increase in capacity resulted from a phenomenon known as the chemical prestressing effect.26 Thus, the LSTP concluded that this approach (i.e., using the plants original specified concrete material properties and relevant sections of applicable design codes) was appropriate (and indeed conservative) for calculating the capacities of ASR-affected structures at Seabrook.27

16.

SMP: Seabrooks SMP is an existing program used to address aging of structural elements within the scope of the maintenance rule, 10 C.F.R. § 50.65.28 The LAR methodology included the addition of several specific provisions to Seabrooks SMP to provide for ongoing ASR detection and monitoring.29 The purpose of these new provisions is two-fold. Purpose (1) is to gather concrete expansion measurements (e.g., from crack width measurements, pin-to-pin mechanical measurements, and extensometer readings from numerous locations in seismic Category I structures) for monitoring against specified acceptance criteria based on the LSTP (Expansion Monitoring Limits) to ensure ASR-related expansion at Seabrook does not exceed levels achieved in the LSTP (i.e., to ensure the LSTP results remain applicable to Seabrook).30 And Purpose (2) is to gather crack width and deformation measurements for monitoring against 25 See, e.g., MPR-4273, Rev. 1, Seabrook Station - Implications of Large-Scale Test Program Results on Reinforced Concrete Affected by Alkali-Silica Reaction at 5-7, fig.5-5 (July 2016) (MPR-4273) (INT019 (NP), INT021 (P)).

26 See, e.g., id. at 5-7 27 MPR Testimony at A91 (NER001).

28 Id. at A158.

29 Id.

30 See infra Part IV.E.

10 specific criteria established in the individual structural evaluations (performed in accordance with the SEM).31

17.

SEM: The SEM prescribes the methodology for performing structural evaluations consistent with the design codes and standards in Seabrooks UFSAR, as modified by the LAR.32 Briefly summarized, the SEM uses Seabrooks existing UFSAR provisions on concrete capacities with the original design concrete specifications (capacity side of the equation)i.e., it calls for no departure from the existing licensing basisprovided that the Expansion Monitoring Limits (in the SMP) are not exceeded (see Purpose (1) of the SMP).33 On the demand side of the equation, the SEM provides a methodology for calculating the ASR loads on a structure, based on in-plane expansion measurements (i.e., crack-width, pin-to-pin mechanical) and structural deformation measurements (see Purpose (2) of the SMP).34 The SEM also provides a three-stage approach for performing the structural evaluations, in which higher stages of the analysis apply more sophisticated methods and use additional field data where refinement is required or desirable.35

18.

The LAR methodology was developed with assistance from multiple external experts and organizations, and was subject to multiple peer reviews and independent evaluations.36 First, NextEra retained MPR and SGHinternationally respected global engineering firms with established track records of analyzing nuclear structuresto assist in 31 See infra Part IV.F.(1).

32 See generally SBK-L-18074, Encl. 3, Simpson Gumpertz & Heger Document No. 170444-MD-01, Rev. 1, Methodology for the Analysis of Seismic Category I Structures with Concrete Affected by Alkali-Silica Reaction, for Seabrook Station (May 31, 2018) (SEM Document) (INT022).

33 Id.

34 Id.

35 Id.

36 MPR Testimony at A86, A88, A223 (NER001); SGH Testimony at A60 (NER004).

11 developing the LAR. MPRs team included Dr. Oguzhan Bayrak from the University of Texas, who is a well-respected structural engineer with over 13 years of ASR-related research experience.37 SGHs team included Dr. Said Bolourchi, who is a well-respected structural engineer with over 40 years of experience in evaluating seismically-rated nuclear structures.

Collectively, these teams consisted of multiple licensed Professional Engineers (the engineering professions highest standard of competence),38 multiple members of well-respected consensus code committees,39 and personnel with decades of ASR-related structural evaluation, testing, and monitoring experience with published works on this topic.40 NextEra also used the Electric Power Research Institute (EPRI) as an independent third party reviewer.41 Among the personnel involved in EPRIs review was Dr. Yann LePape, a well-respected ASR researcher currently performing ASR-related testing at Oak Ridge National Laboratory.42 Dr. Bruce Ellingwood of Colorado State Universityan internationally-recognized authority on structural load modeling and structural reliability theoryprovided a third-party review of the LAR analytical methodology, including its treatment of ASR loads and load factors.43 Talisman International, LLC (Talisman) provided an independent third-party review of the LAR.44 During the early stages of NextEras efforts to develop a methodology to address ASR, Dr.

37 Tr. at 266-67; see also Dr. Oguzhan Bayrak Curriculum Vitae (NER010).

38 See, e.g., Glenn Bell Curriculum Vitae (NER032); Matthew Sherman Curriculum Vitae (NER033); Dr.

Oguzhan Bayrak Curriculum Vitae (NER010); Dr. Said Bolourchi Curriculum Vitae (NER031).

39 See, e.g., Glenn Bell Curriculum Vitae (NER032); Matthew Sherman Curriculum Vitae (NER033); Dr.

Oguzhan Bayrak Curriculum Vitae (NER010); Dr. Said Bolourchi Curriculum Vitae (NER031).

40 See, e.g., Matthew Sherman Curriculum Vitae (NER033); Dr. Oguzhan Bayrak Curriculum Vitae (NER010).

41 MPR Testimony at A86 (NER001).

42 Tr. at 270; see also N. Ezell et al., Experimental Collaboration for Thick Concrete Structures with Alkali-Silica Reaction (2018) (NER047).

43 MPR Testimony at A88 (NER001); SGH Testimony at A60 (NER004).

44 MPR Testimony at A88 (NER001).

12 Kevin Folliard of the University of Texasan internationally-recognized authority on ASR provided insights on ASR from a materials perspective and on application of provisions within the FHWA Guideline (which he co-authored).45 Furthermore, the LAR was submitted to the NRCan independent regulatory agencywhich extensively reviewed NextEras approach against the agencys codified regulatory requirements. The NRC also contracted with subject matter experts at Brookhaven National Laboratory to assist its review.46 And finally, NextEra presented its approach, and the NRC presented its proposed findings, to the Advisory Committee on Reactor Safeguards (ACRS), which is an independent body statutorily mandated by the Atomic Energy Act of 1954, and whose distinguished members are drawn from outside organizations, national laboratories, and academic institutions, several of whom have substantial structural engineering and material science experience.47 Collectively, this cadre of contributors and reviewers includes numerous preeminent authorities, several experts with significant ASR experience, a balanced mix of engineering theoreticians and practitioners, and many decades of experience in structural engineeringwhich is by and large the most relevant field of expertise for this LAR, which pertains to confirmations of structural adequacy.

19.

C-10s Petition, filed on April 10, 2017, originally proposed ten contentions (A through J).48 These contentions were based primarily on statements from Dr. Paul Brown, and only purported to challenge the LAR as presented in the Original LAR Package (i.e., it did not acknowledge or challenge the LAR Supplement).49 45 Id. at A211 (NER001); FHWA Guideline (NER013).

46 MPR Testimony at A88, A89, A223 (NER001); SGH Testimony at A60 (NER004).

47 MPR Testimony at A42 (NER001); Tr. at 268-69.

48 Petition at 2-3.

49 Id. at 3-15.

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20.

On October 7, 2017, in LBP-17-7, the Board found portions of five contentions A, B, C, D, and Hadmissible, but rejected the remaining contentions.50 The Board reformulated the admissible portions into a single admitted contention, as follows:

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.51

21.

NextEra appealed the Boards decision to the Commission, which affirmed the Boards ruling. As relevant to the scope of the Contention admitted for adjudication in this proceeding, the Commission held that [t]he five elements of the reformulated contention relate as follows.

In Contention D, C-10 challenges the overall representative nature of the data from the large-scale test program.

In Contention A, as admitted, C-10 challenges the effectiveness of crack width indexing and extensometer deployment as tools for determining the presence and extent of ASR in safety-related structures. C-10s concerns regarding these monitoring techniques arise from the question of whether the test program results can adequately predict the effectiveness of crack width indexing and extensometer deployment as monitoring techniques at Seabrook.

In Contentions B and C, taken together, C-10 contends that results gathered via the test program do not provide information comparable to that obtainable by core sampling and that, without such information, NextEra cannot understand the progression of ASR at Seabrook.

And finally, in Contention H, as admitted, C-10 challenges the frequency of proposed inspection intervals on the ground that the test program results on which the intervals are based are not representative of Seabrook concrete.52 50 Seabrook, LBP-17-7, 86 NRC at 68.

51 Id. at 127.

52 NextEra Energy Seabrook LLC (Seabrook Station, Unit 1) CLI-18-4, 87 NRC 89, 94-95 (2018).

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22.

As the Board emphasized, the key issue is Contention Ds challenge to the representativeness of the large-scale test program, whereas the remaining portions of the admitted contentions (A, B, C, and H) merely assert consequences stemming from this alleged lack of representativeness.53 In other words, and as confirmed by the Commission, the Board did not admit the Contention as a broad challenge to the adequacy of NextEras monitoring, acceptance criteria, and inspection intervals on unlimited grounds. Rather, those aspects of the LAR are subject to challenge in this proceeding only to the extent they relate to the key issue of LSTP representativeness, and are within the envelope of bases pled in C-10s original Petition.

23.

Notably, the Board rejected a contention seeking to challenge NextEras monitoring of rebar, reasoning that rebar monitoring is conducted under a separate program (i.e.,

not part of the LAR) and thus not within the scope of this proceeding.54 The Board also rejected C-10s demand that NextEra adopt C-10s preferred alternative approach to regulatory compliance and include a methodology to test materials up to and beyond their point of failure.55 Such arguments are inadmissible because, in licensing proceedings, the question before the NRC is whether the applicants approach complies with regulatory requirements, not whether there exists some alternative or arguably better means of doing so.

24.

The NRC conducted extensive oversight of NextEras efforts to address ASR at Seabrook. In summary, from 2010 to 2018, the Staff 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 specifically on the topic of 53 Seabrook, LBP-17-7, 86 NRC at 127.

54 Id. at 133.

55 Id. at 134-35.

15 ASR. This included several inspections and an onsite audit, collectively around five weeks of onsite time, all of which occurred during the time period from 2013 to 2015.56 These inspections observed, on a sampling basis, the setup of the program and the facilities, fabrication and concrete pour, and testing of the specimens.57 The Staff also conducted five ASR-related onsite audits at Seabrook, four of which specifically reviewed the Seabrook ASR expansion monitoring program.58

25.

On October 24, 2018, C-10 advised the parties that Dr. Victor Saouma, not Dr.

Brown (whose comment letters C-10 cited as support for the original Petition) would be its witness at the evidentiary hearing.59 56 NRC Staff Testimony of Angela Buford, Bryce Lehman, and George Thomas at A.10 (July 24, 2019) (NRC Testimony) (NRC001-R).

57 Id. See also Letter from R. Lorson, NRC, to K. Walsh, Seabrook Station, Unit No. 1 - Confirmatory Action Letter Follow-up Inspection - NRC Inspection Report 05000443/2012010 (Aug. 9, 2013) (NRC026); Letter from G. Dentel, NRC, to K. Walsh, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2013005 (Jan. 30, 2014) (NRC027); Letter from G. Dentel, NRC, to K. Walsh, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014002 (May 6, 2014)

(NRC028); Letter from G. Dentel, NRC, to D. Curtland, NextEra, Seabrook Station, Unit No. 1 - NRC Integrated Inspection Report 05000443/2014005 (Feb. 6, 2015) (NRC030); and Letter from F. Bower, III, NRC, to D. 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) (NRC032).

58 NRC Testimony at A10 (NRC001-R); see also Seabrook ASR-Monitoring Program Audit Report (Dec. 17, 2015) (NRC018); Letter from R. Plasse, NRC, to K. Walsh, NextEra, Aging Management Program Audit Report Regarding the Seabrook Station License Renewal Application (TAC No. ME4028) (Dec. 23, 2013)

(NRC041); Letter from T. Tran, NRC, to E. McCartney, NextEra, Alkali Silica Reaction Monitoring Aging Management Program Audit Report Regarding the Seabrook Station, Unit 1, License Renewal (CAC No.

ME4028) (Dec. 26, 2016) (NRC042); Letter from J. Poole, NRC, to M. 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-2016-0007) (July 26, 2017) (NRC043); and Letter from J.

Poole, NRC, to M. Nazar, NextEra, Seabrook Station, Unit No. 1 - Site Visit Report Regarding Alkali-Silica Reaction License Amendment Request and License Renewal Alkali-Silica Reaction Aging Management Program Review (CAC No. MF8260; EPID L-2016-LLA-0007) (May 21, 2018) (NRC044).

59 Letter from N. Treat to P. Bessette and A. Ghosh, Monthly Disclosure: Addition of expert Victor E. Saouma and request for access to protected information, Pursuant to 10 C.F.R. § 2.336; NextEra Energy Seabrook, LLC (Seabrook Station Unit 1), Docket No. 50-443-LA-2 (Oct. 24, 2018) (ML18297A149).

16

26.

On December 14, 2018, the ACRS concluded its review of the LAR and issued the following conclusions:

NextEra License Amendment Request 16-03 establishes a robust analytical methodology, supported by a comprehensive large scale test program, for the treatment and monitoring of alkali-silica reaction-affected seismic Category I structures at Seabrook.

The NextEra License Renewal Application includes two new Aging Management Programs to monitor alkali-silica reaction and building deformation. These incorporate the test program results and license amendment request methodology and assure that the effects of alkali-silica reaction will be effectively tracked and evaluated through the end of the License Renewal Application period of extended operation.

The staff safety evaluations of the license amendment request and alkali-silica reaction related Aging Management Programs in the License Renewal Application provide thorough assessments and findings. We agree with the staffs conclusion that NextEras programs are acceptable.60

27.

On March 11, 2019, the NRC Staff approved the LAR, and issued the license amendment and the Staffs final safety evaluation (Final SE), which concluded as follows:

the proposed plant-specific method of evaluation for design evaluation of seismic Category I reinforced concrete structures affected by ASR at Seabrook is acceptable and provides reasonable assurance that these structures continue to meet the relevant requirements of 10 CFR Part 50, Appendix A, GDC [General Design Criteria] 1, 2, 4, 16 (Containment only) and 50 (Containment only), and 10 CFR Part 50, Appendix B.61

28.

As noted above, NextEra revised and refined its LAR through various submissions to the NRC between the time it filed the Original LAR Package and the time the NRC issued the requested license amendment. Notably, C-10 never sought to amend its admitted Contention to challenge the updated methodology in the final version of the LAR, and 60 Letter from M. Corradini, Chairman, ACRS, to K. Svinicki, Chairman, NRC, Seabrook Station Unit 1 License Renewal Application: Review of Licensee Program Addressing Alkali-Silica Reaction, (Dec. 14, 2018)

(NRC048).

61 Final SE (INT024 (NP), INT025 (P)).

17 never submitted a new contention seeking to challenge any information in the LAR Supplement or any of the RAI Responses.

29.

On April 23, 2019, prior to the deadline for submission of written testimony, NextEra filed a motion in limine seeking to preemptively exclude testimony and exhibits related to the structure deformation monitoring portion of the LAR (First MIL).62 On June 7, 2019, the Board issued an order deferring its ruling on the First MIL until it had reviewed the evidentiary submissions.63

30.

The parties filed written testimony and exhibits on June 10, 2019 (C-10 initial testimony), July 24, 2019 (NextEra and NRC Staff testimony), and August 24, 2019 (C-10 rebuttal testimony).64

31.

On September 4, 2019, C-10 filed a motion for leave to submit Supplemental Rebuttal testimony.65 The Board granted that motion on September 16, 2019, and invited NextEra and the NRC Staff to file their own responsive testimony.66 The NRC Staff did so on September 20, 2019, as did NextEra on September 22, 2019.67

32.

On September 9, 2019, after the submission of written testimony, NextEra filed a renewed and expanded motion in limine seeking to strike or exclude testimony and exhibits on a 62 NextEras Motion in Limine to Exclude Testimony and Exhibits Regarding Structure Deformation Monitoring (Apr. 23, 2019) (ML19114A076) (First MIL).

63 ASLB, Order (Ruling on NextEras Motion in Limine) (June 7, 2019) (unpublished) (ML19158A512) (Order on First MIL).

64 Pursuant to the Boards invitation, NextEra and C-10 filed additional exhibits prior to the evidentiary hearing.

65 C-10 Research and Education Foundations Motion for Leave to File Supplemental Rebuttal Testimony (Sept.

4, 2019) (ML19247D593).

66 ASLB Order (Granting C-10s Motion for Leave to File Supplemental Rebuttal Testimony) (Sept. 16, 2019)

(ML19259B318).

67 Staff Testimony in Response to Exhibit INT030 (Sept. 20, 2019) (NRC090); Testimony of NextEra Witnesses John Simons, Christopher Bagley, Oguzhan Bayrak, and Edward Carley in Response to Exhibit INT030 (Sept.

22, 2019) (NER076).

18 range of topics (Second MIL) that exceeded the scope of the admitted contention.68 On September 20, 2019, the Board deferred ruling on the Second MIL until after the evidentiary hearing.69

33.

The evidentiary hearing was held across four days between September 24-27, 2019, in Newburyport, Massachusetts.70

34.

On September 30, 2019, C-10 filed a post-hearing motion seeking to compel NextEra to produce mineralogy data and requesting leave to submit supplemental testimony on that data (Second Supplemental Testimony).71 At the Boards request,72 C-10 submitted a clarification of that request on October 28, 2019.73 That clarification also included a motion for leave to submit further supplemental testimony on a Seabrook petrography document (Third Supplemental Testimony).74 68 NextEras Motion in Limine to Strike or Exclude Portions of C-10s Testimony and Exhibits (Sept. 9, 2019)

(ML19252B232) (Second MIL).

69 ASLB Order (Deferring Ruling on NextEras Second Motion in Limine) (Sept. 20, 2019) (unpublished)

(ML19263E820) (Order on Second MIL).

70 Tr. at 214-1203.

71 C-10 Research and Education Foundations Motion to Compel Production of Mineralogy Data and Request for Opportunity to Submit Supplemental Written Testimony Regarding the Data (Sept. 30, 2019)

(ML19272B325).

72 ASLB Memorandum (Request for Clarification) (Oct. 16, 2019) (ML19289D761).

73 C-10 Research and Education Foundations Response to ASLB Memorandum and Motion to Submit Additional Exhibits Regarding Petrographic Observations and Analyses of ASR at Seabrook (Oct. 28, 2019)

(Proprietary) (ML19301C924) (re-filed Oct. 30, 2019 as Non-Proprietary) (ML19304B352).

74

[As of the due date for submission of the FOF/COL, the Board had neither ruled on these motions nor closed the evidentiary record.]

19 III.

APPLICABLE LEGAL AND REGULATORY STANDARDS A.

License Amendment Standards

35.

Pursuant to 10 C.F.R. §§ 50.92 and 50.57(a)(3) and (6), to grant the LAR, the NRC must find that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation of the plant as proposed in the LAR, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

36.

The LAR implicates GDC 1, 2, 4, 16, and 50, which are codified in 10 C.F.R. Part 50, Appendix A, and impose general criteria for the design of nuclear power plants on topics such as design bases for protection against natural phenomena, and the containment design basis.

Also, the activities related to the changes proposed in the LAR are subject to the NRCs Quality Assurance (QA) regulations in 10 C.F.R. Part 50, Appendix B. Notably, the Contention does not challenge the LARs compliance with any of these requirements.

B.

The Reasonable Assurance Standard

37.

Longstanding Commission precedent makes clear that the reasonable assurance standard does not require an applicant to meet an absolute or beyond a reasonable doubt standard.75 In other words, reasonable assurance is not synonymous with absolute assurance. Likewise, reasonable assurance is not susceptible to formalistic quantification (i.e.,

75 AmerGen Energy Co., LLC, (Oyster Creek Nuclear Generating Station), CLI-09-7, 69 NRC 235, 262 n.142 (2009); Commonwealth Edison Co. (Zion Station, Units 1 & 2), ALAB-616, 12 NRC 419, 421 (1980); N. Anna Envtl. Coal. v. NRC, 533 F.2d 655, 667-68 (D.C. Cir. 1976) (rejecting the argument that reasonable assurance requires proof beyond a reasonable doubt and noting that the licensing board equated reasonable assurance with a clear preponderance of the evidence).

20 95% confidence) or mechanistic application.76 The NRC historically has interpreted reasonable assurance with the understanding that some risks may be tolerated and something less than absolute protection is required.77 As particularly relevant here, [t]he mere casting of doubt on some aspect of an application is legally insufficient to defeat a finding of reasonable assurance.78

38.

In applying the reasonable assurance standard, the Commission takes a case-by-case approach, exercising sound technical judgment and verifying the applicants compliance with Commission regulations based on all relevant facts and circumstances79 Importantly, an intervenors demand for compliance with a standard beyond the reasonable assurance standard is legally unsustainable because a licensing board cannot impose requirements that exceed those in the regulation[s].80 Furthermore, if an applicants supporting analyses are grounded on reasonable assumptions, data, techniques of analysis and interpretations, a finding of reasonable assurance can be made even though other data and methods might have been used.81 In other words, an intervenors mere presentation of an alternative method of regulatory compliance is not sufficiently probative to demonstrate an alleged lack of reasonable assurance.

76 AmerGen Energy Co., LLC (Oyster Creek Nuclear Generating Station), LBP-07-17, 66 NRC 327, 340 (2007),

affd CLI-09-07, 69 NRC 235 (2009).

77 Memorandum from F. Brown to New Reactor Business Line, Expectations for New Reactor Reviews at 4 (Aug. 29, 2018) (ML18240A410).

78 Private Fuel Storage, L.L.C. (Indep. Spent Fuel Storage Installation), CLI-00-13, 52 NRC 23, 31 (2000) (citing La. Energy Servs. (Claiborne Enrichment Center), CLI-97-15, 46 NRC 297 (1997); N. Atl. Energy Serv. Corp.

(Seabrook Station, Unit 1), CLI-99-6, 49 NRC 201, 222 (1999)).

79 See Oyster Creek, CLI-09-7, 69 NRC at 262-63, 262 n.143; Entergy Nuclear Generation Co. (Pilgrim Nuclear Power Station), CLI-10-14, 71 NRC 449, 465-66 (2010).

80 Entergy Nuclear Operations, Inc. (Palisades Nuclear Plant), CLI-15-22, 82 NRC 310, 317 (2015).

81 Long Island Lighting Co. (Shoreham Nuclear Power Station, Unit 1), LBP-88-13, 27 NRC 509, 548 (1988),

affirmed in part, vacated in part, remanded by ALAB-905, 28 NRC 515 (1988). Cf. Palisades, CLI-15-22, 82 NRC at 317-18 (noting that there may be alternate or alternative methods by which a licensee can demonstrate reasonable assurance).

21 C.

Burden of Proof

39.

At the hearing stage, an intervenor has the initial burden of going forward; that is, it must provide sufficient, probative evidence to establish a prima facie case for the claims made in the admitted contention.82 The mere admission of a contention does not satisfy this burden.83 If (and only if) the intervenor establishes a prima facie case on a particular claim, then the burden shifts to the applicant to provide sufficient evidence to rebut the intervenors contention.84 To prevail, the applicants position need only be supported by a preponderance of the evidence.85

40.

At the admissibility stage, the petitioner has the ironclad obligation to examine the available documentation with sufficient care to support the foundation for a contention.86 This obligation applies with equal, if not greater, force at the hearing stage.87 82 Oyster Creek, CLI-09-07, 69 NRC at 269 (quoting Consumers Power Co. (Midland Plant, Units 1 & 2),

ALAB-123, 6 AEC 331, 345 (1973) (The ultimate burden of proof on the question of whether the permit or license should be issued is... upon the applicant. But where... one of the other parties contends that, for a specific reason... the permit or license should be denied, that party has the burden of going forward with evidence to buttress that contention. Once he has introduced sufficient evidence to establish a prima facie case, the burden then shifts to the applicant who, as part of his overall burden of proof, must provide a sufficient rebuttal to satisfy the Board that it should reject the contention as a basis for denial of the permit or license.)

(emphasis in original)); see also Vt. Yankee Nuclear Power Corp. v. Natural Res. Def. Council, 435 U.S. 519, 554 (1978) (upholding this threshold test for intervenor participation in licensing proceedings); Phila. Elec. Co.

(Limerick Generating Station, Units 1 & 2), ALAB-262, 1 NRC 163, 191 (1975) (holding that the intervenors had the burden of introducing evidence to demonstrate that the basis for their contention was more than theoretical).

83 See Oyster Creek, CLI-09-07, 69 NRC at 268-70.

84 See, e.g., id. at 269; La. Power & Light Co. (Waterford Steam Electric Station, Unit 3), ALAB-732, 17 NRC 1076, 1093 (1983) (citing Midland, ALAB-123, 6 AEC at 345); see also 10 C.F.R. § 2.325.

85 See Pac. Gas & Elec. Co. (Diablo Canyon Nuclear Power Plant, Units 1 and 2), ALAB-763, 19 NRC 571, 577; Oyster Creek, CLI-09-07, 69 NRC at 263.

86 See Duke Power Co. (Catawba Nuclear Station, Units 1 & 2), ALAB-687, 16 NRC 460, 468 (1982), vacated in part on other grounds, CLI-83-19, 17 NRC 1041 (1983).

87 See Entergy Nuclear Operations, Inc. (Indian Point Nuclear Generating Units 2 & 3), LBP-13-13, 78 NRC 246, 301 n.308 (2013) (rejecting an experts claims based on some averages and a gut feeling, rather than a thorough a review of available documentation).

22 D.

Scope of Contentions and Motions in Limine

41.

The evidentiary hearing is limited to the admitted Contention. And the reach of a contention necessarily hinges upon its terms coupled with its stated bases.88 Importantly, an intervenor may not freely change the focus of an admitted contention at will to add a host of new issues and objections that could have been raised at the outset.89 Absent a formal amendment of the admitted contention, intervenors may only develop their admitted contentions within the boundaries of the bases pled in the original petition. 10 C.F.R. § 2.309(f)(1)(vi) has long been held to require petitioners to specifyat the petition stagethe specific and identifiable portions of the application that are being disputed.90

42.

The Commission has consistently and explicitly held that intervenors may not unilaterally expand the scope of their admitted contentions at the hearing stage to challenge new portions of the application or raise new bases outside the boundaries of the bases as pled and admitted.91 10 C.F.R. § 2.337(a) provides that [o]nly relevant, material, and reliable evidence which is not unduly repetitious will be admitted,92 and 10 C.F.R. § 2.319(e) empowers the Board to [r]estrict irrelevant, immaterial, unreliable, duplicative or cumulative evidence and/or arguments from the record. Although boards have considerable discretion in the conduct of 88 Entergy Nuclear Generation Co. (Pilgrim Nuclear Power Station), CLI-10-11, 71 NRC 287, 309 (2010)

(emphasis in original) (citing Pub. Serv. Co. of N.H. (Seabrook Station, Units 1 & 2), ALAB-899, 28 NRC 93, 97 (1988), affd sub nom. Massachusetts v. NRC, 924 F.2d 311 (D.C. Cir.), cert. denied, 502 U.S. 899 (1991).

89 Order on First MIL at 7 (citing Duke Energy Corp. (McGuire Nuclear Station, Units 1 & 2; Catawba Nuclear Station, Units 1 & 2), CLI-02-28, 56 NRC 373, 386 (2002)).

90 Ga. Power Co., et al. (Vogtle Electric Generating Plant, Units 1 & 2), CLI-93-16, 38 NRC 25, 41 (1993). See also Yankee Atomic Elec. Co. (Yankee Nuclear Power Station), CLI-05-15, 61 NRC 365, 381 (2005).

91 See, e.g., NextEra Energy Seabrook, LLC (Seabrook Station, Unit 1), CLI-12-5, 75 NRC 301, 310 n.50 (We remind our boards, however, of the need to specify each basis relied upon for admitting a contention....

Contrary to the Boards statement (LBP-11-2, 73 NRC at 56), an admitted contention is defined by its bases.).

92 See also 10 C.F.R. § 2.337(a) (providing that [i]mmaterial or irrelevant parts of an admissible document will be segregated and excluded so far as is practicable).

23 evidentiary hearings, denials of motions in limine that result in hearings beyond the proper scope of the proceeding constitute reversible procedural error.93

43.

This longstanding principle has been enshrined in numerous Commission adjudicatory decisions. For example, in Vogtle, the Commission upheld a Board ruling excluding testimony that strayed beyond the scope of the original contention and bases, as pled and admitted, noting that the limitations in the initial pleadings defined the scope of the...

contention.94 Similarly, in Pilgrim, the Commission reiterated this longstanding precedent:

NRC threshold contention standards require petitioners to review application materials and set forth their contentions with particularity. Where any issue arises over the proper scope of a contention, NRC opinions have long referred back to the bases set forth in support of the contention.... Our contention rules require reasonably specific factual and legal allegations at the outset to assure that matters admitted for hearing... provide notice to opposing parties of the issues they will need to defend against.95

44.

Intervenors certainly are not required to prove their case, or even to provide an exhaustive list of possible bases, at the contention admissibility stage.96 But, the Commission explicitly prohibits distinctly new complaints to be added at will as litigation progresses,97 including new arguments or challenges by a newly retained expert.

45.

For rebuttal testimony, the scope of permissible evidence and arguments is even more limited.98 In essence, rebuttal evidence is that for which the need was entirely unforeseen.

93 See, e.g., Entergy Nuclear Operations, Inc. (Indian Point Nuclear Generating Units 2 & 3), CLI-15-6, 81 NRC 340, 377 (2015).

94 S. Nuclear Operating Co. (Early Site Permit for Vogtle ESP Site), CLI-10-5, 71 NRC 90, 100-02 (2010).

95 Pilgrim, CLI-10-11, 71 NRC at 308-09 (2010) (emphasis added and citations omitted).

96 La. Energy Servs., LP (National Enrichment Facility), CLI-04-35, 60 NRC 619, 623 (2004).

97 Pilgrim, CLI-10-11, 71 NRC at 309 (2010) (citation and internal quotation marks omitted).

98 See, e.g., La. Energy Servs., L.P. (National Enrichment Facility), LBP-06-15, 63 NRC 591, 620 (2006)

(reciting the Boards action striking portions of prefiled rebuttal testimony that fell outside the scope of any admitted contention and/or the permissible scope of rebuttal testimony).

24 Its purpose is simply to permit a litigant to counter new, unforeseen facts brought out in the other sides case.99 Thus, rebuttal evidence is admissible only insofar as it address matters which the party objectively could not have raised earlier. Fundamental fairness requires that rebuttal may not include arguments or information that reasonably should have been, but were not, raised in the partys case-in-chief.100 Similarly, parties may not use rebuttal to add cumulative evidence to bolster their original case.101 [M]erely revisiting evidence earlier presented, but in more detailed and comprehensive fashion is impermissible in rebuttal.102 IV.

FACTUAL FINDINGS AND LEGAL CONCLUSIONS

46.

As briefly summarized below, a preponderance of the evidence explains that the LARtogether with substantial supporting informationdemonstrates: reasonable assurance that the health and safety of the public will not be endangered, and authorized activities will be conducted in compliance with the Commissions regulations; issuance of the amendment is not inimical to the common defense and security; and all GDC have been satisfied, as required by 10 C.F.R. §§ 50.92, 50.57(a)(3) and (6), and Appendix A.

99 Faigin v. Kelly, 184 F.3d 67, 85 (1st Cir. 1999).

100 See, e.g., Progress Energy Fla., Inc. (Combined License Application for Levy County Nuclear Power Plant, Units 1 and 2), LBP-09-22, 70 NRC 640, 655 (2009) (Being in the nature of rebuttal, the response, rebuttal testimony, and rebuttal exhibits are not to advance any new affirmative claims or arguments that should have been, but were not, included in the partys previously filed initial written statement); see also Amergen Energy Co., LLC (License Renewal for Oyster Creek Nuclear Generating Station), Licensing Board Order (Prehearing Conference Call Summary, Case Management Directives, and Final Scheduling Order) at 5-6 (Apr. 17, 2007) (ML071070437); Dominion Nuclear N. Anna, LLC (Early Site Permit for North Anna ESP Site), Licensing Board Order (Revised Scheduling Order) at 4 (Mar. 1, 2006) (ML060610623); Rockwell Intl Corp. Rocketdyne Div. (Special Material License Number SNM-21), LBP-89-27, 30 NRC 265, 269 (1989)

(permitting rebuttal testimony only with respect to new or surprise material included in the opposing partys submittals).

101 See 10 C.F.R. §§ 2.337(a) ([o]nly... evidence which is not unduly repetitious will be admitted); 2.319(e)

(empowering the Board to [r]estrict... duplicative or cumulative evidence and/or arguments from the record).

102 Cates v. Sears, Roebuck & Co., 928 F.2d 679, 685 (5th Cir. 1991).

25 A.

Witnesses (1)

NextEras Expert Witnesses

47.

Two of NextEras witnesses (Michael Collins and Edward Carley) are NextEra employees who work at Seabrook. Mr. Collins is the Director of Engineering for Seabrook and has more than 38 years of professional experience in the nuclear power industry.103 Mr. Collins is responsible for the engineering management and technical oversight of ASR-related activities at Seabrook, and has extensive first-hand knowledge of the facility, the initial identification of ASR at the plant, the development of the LAR, and the execution of the SMP.

48.

Mr. Carley is employed by NextEra as a Nuclear Engineering Supervisor for Seabrook.104 He has more than 38 years of professional experience in the nuclear power industry. Mr. Carley oversaw NextEras development and regulatory review of the LAR, including the development of the overall approach to the first-in-the-industry aging management program for ASR in the SMP.105

49.

Two of NextEras witnesses (John Simons and Christopher Bagley) work for MPR Associates, Inc. (MPR), a contractor to NextEra.106 Mr. Simons works as General Manager of Projects and has extensive first-hand knowledge of NextEras multi-year program to evaluate ASR at Seabrook, including the LSTP and the SMP.107 He has more than 32 years of professional experience in the nuclear power industry, and is an author and contributor on numerous Electric Power Research Institute (EPRI) reports and NUREG publications on 103 Michael Collins Biography (NER006); MPR Testimony § I.A (NER001).

104 Edward Carley Resume (NER011); MPR Testimony § I.E (NER001).

105 MPR Testimony at A30 (NER001).

106 See John Simons Curriculum Vitae (NER008); Christopher Bagley Curriculum Vitae (NER009); MPR Testimony §§ I.B-C (NER001).

107 John Simons Curriculum Vitae (NER008); MPR Testimony § I.B (NER001).

26 engineering topics relevant to the nuclear industry, including aging management issues on concrete structures and large-scale testing. Mr. Simons work included the development and conduct of the LSTP conducted at FSEL and the application of the LSTP results as inputs to NextEras SMP.108

50.

Mr. Bagley is a Supervisory Engineer at MPR and also has extensive first-hand knowledge of NextEras multi-year program to evaluate ASR at Seabrook, including the LSTP and the SMP.109 He has more than 15 years of professional experience in the nuclear power industry and served as an officer and engineer in the United States Navys Naval Reactors Program. Mr. Bagley worked on the development and execution of the LSTP, the application of LSTP results to Seabrook, and the methodology for calculating past ASR expansion. Mr. Bagley has prepared reports for EPRI on addressing ASR in concrete at nuclear plants.110

51.

Dr. Oguzhan Bayraks professional and educational qualifications are summarized in his curriculum vitae.111 Dr. Bayrak is a Distinguished Teaching Professor in the Civil, Architectural, and Environmental Engineering Department of the University of Texas Cockrell School of Engineering. Dr. Bayrak was previously the Director of the FSEL at the University of Texas and held that position during the LSTP. He holds a Doctorate (Ph.D.) in Civil Engineering from the University of Toronto and is a licensed Professional Engineer. Dr.

Bayrak has more than 20 years of professional experience in structural engineering and focuses on the behavior, analysis, and design of reinforced and prestressed concrete structures, the evaluation of structures in distress, and earthquake engineering. Dr. Bayrak has over 13 years of 108 MPR Testimony at A10-A11.

109 Christopher Bagley Curriculum Vitae (NER009); MPR Testimony § I.C (NER001).

110 MPR Testimony at A18.

111 Dr. Oguzhan Bayrak Curriculum Vitae (NER010); MPR Testimony § I.D (NER001).

27 experience related to ASR,112 and has been published or presented over 200 times in technical journals, conference proceedings, books, technical reports, and other publications. He is a Fellow of the American Concrete Institute (ACI) and serves on several technical committees including the Committee on Reinforced Concrete Columns and the Committee on Shear and Torsion. Dr. Bayrak is also a member of the Precast/Prestressed Concrete Institute (PCI). Dr.

Bayrak is the chair for the Federation Internationale du Betons (fib, also known as the International Federation for Structural Concrete) committee on shear, is the deputy chair for fibs Commission 2, Analysis and Design of Concrete Structures, and serves on the editorial board of Structural Concrete (the official technical journal of fib). In addition to his work on the LSTP, Dr. Bayrak has supervised four ASR research projects, other than the LSTP; these included field assessments of ASR-affected concrete and fabrication of test specimens that experienced accelerated ASR progression.113

52.

NextEras final three witnesses (Dr. Said Bolourchi, Glenn Bell, and Matthew Sherman) are Senior Principals at Simpson Gumpertz & Heger Inc. (SGH), a contractor to NextEra, and all are licensed Professional Engineers in multiple states.114 Dr. Bolourchi is a Senior Principal at SGH, and has extensive first-hand knowledge of the development of the LAR, and in particular the SEM.115 He is the Principal-in-Charge for all SGH projects associated with the evaluation of seismic Category I structures at Seabrook, including oversight and supervision of the testing and petrography of Seabrooks cores, field measurements for structural evaluations, structural evaluations of Seabrooks structures under the SEM, 112 Tr. at 267.

113 MPR Testimony at A22 (NER001).

114 SGH Testimony §§ I.A-C (NER004); Dr. Said Bolourchi Curriculum Vitae (NER031); Glenn Bell Curriculum Vitae (NER032); Matthew Sherman Curriculum Vitae (NER033).

115 Dr. Said Bolourchi Curriculum Vitae (NER031); SGH Testimony § I.A (NER004).

28 development of ASR loads and load factors, and development of structural monitoring parameters. He holds a Ph.D. from the Massachusetts Institute of Technology, and has more than 40 years of professional experience in the nuclear power industry. Dr. Bolourchi has extensive experience related to seismic evaluations of nuclear structures and non-linear modeling and analysis of highly-complex structural loading.116

53.

Mr. Bell is a Senior Principal at SGH and has extensive first-hand knowledge of the development of the SEM. He has more than 44 years of professional experience in the structural engineering industry, and was the CEO of SGH from 1995 through 2016, and Chair of its Board of Directors from 2016 through 2018.117 Mr. Bell supervised the development of the ASR load factors used in the SEM and the structural analysis of the Containment Building at Seabrook. He is also the President-Elect of the Structural Engineering Institute and a Board Trustee of the Institution of Structural Engineers.118

54.

Mr. Sherman is a Senior Principal at SGH and has extensive first-hand knowledge of the development of the SEM. He has more than 25 years of professional experience in the civil/structural engineering industry with a focus on construction materials, repair/rehabilitation, and testing.119 In his current position, he oversees the fieldwork, testing, and petrographic studies associated with the structural evaluation of Seabrook structures affected by ASR, including the application of proposed structural monitoring parameters and frequency of monitoring included as inputs to the SMP. Mr. Sherman is a Fellow of the ACI and the International Concrete Repair Institute (ICRI), and serves on several ACI committees 116 Tr. at 363-64, 1105; SGH Testimony at A4-A6 (NER004).

117 Glenn Bell Curriculum Vitae (NER032); SGH Testimony §§ I.A-C (NER004).

118 Glenn Bell Curriculum Vitae (NER032); SGH Testimony at A10-A11 (NER004).

119 Matthew Sherman Curriculum Vitae (NER033); SGH Testimony § I.C (NER004).

29 including the Committee on Durability of Concrete and Design of Nuclear Structures. Mr.

Sherman has worked on ASR-related structural engineering issues throughout his career.120

55.

Based on the above, we conclude that NextEras witnesses collectively are qualified through knowledge, skill, directly-relevant experience, training, and education to provide expert witness testimony on the topics of: (1) ASR; (2) structural engineering, testing and analysis; (3) nuclear regulation and licensing; (4) NextEras LAR (including the LSTP, the SMP, and the SEM); (5) Seabrooks seismic Category I structures; (6) the NRCs oversight of NextEras ASR-related activities and review of the LAR; and (7) consensus codes for structural evaluation.

(2)

NRC Staffs Expert Witnesses

56.

Ms. Angela Buford is a structural engineer in the Division of Engineering, Office of Nuclear Reactor Regulation (NRR) at the NRC.121 In that role, Ms. Buford is responsible for performing safety evaluations of NRC licensing requests and supporting the NRCs reactor oversight activities, including providing technical and regulatory expertise in the structural engineering area for inspection and enforcement activities. She has been involved in the review of ASR at Seabrook since 2010, including participation in various audits of the LSTP and inspections of Seabrooks seismic Category I structures. Ms. Buford is the primary author of the NRC Staffs safety evaluation report (SER) for the Seabrook License Renewal Application (LRA) and peer reviewed its safety evaluation (SE) for the LAR.122 120 Tr. at 329-30; SGH Testimony at A15-A17.

121 Statement of Professional Qualifications of Angela Buford (NRC002); NRC Testimony at A.1a, A.2a, A.3a (NRC001-R).

122 NRC Testimony at A.3a (NRC001-R).

30

57.

Mr. Bryce Lehman is a structural engineer in the Division of Engineering, Office of NRR, at the NRC.123 Mr. Lehman is responsible for performing safety evaluations of NRC licensing requests and supporting the NRCs reactor oversight activities, including providing technical and regulatory expertise in the structural engineering area for inspection and enforcement activities, and consensus codes and standards activities. He has been involved in the review of ASR at Seabrook since 2010, including participation in various audits of the LSTP and inspections of Seabrooks seismic Category I structures. Mr. Lehman is a co-author of the NRC Staffs safety evaluation (SE) for the LAR.124

58.

Mr. George Thomas is a senior structural engineer in the Division of Engineering, Office of NRR, at the NRC.125 Mr. Thomas is responsible for performing safety evaluations of NRC licensing requests and supporting the NRCs reactor oversight activities, including providing technical and regulatory expertise in the structural engineering area for inspection and enforcement activities, and consensus codes and standards activities. He has been involved in the review of ASR at Seabrook since 2011, including participation in various audits of the LSTP and inspections of Seabrooks seismic Category I structures. Mr. Thomas is a co-author of the NRC Staffs safety evaluation (SE) for the LAR.126

59.

Mr. Jacob Philip is a senior geotechnical (civil) engineer in the Structural, Geotechnical, and Seismic Engineering Branch, Division of Engineering, Office of Nuclear 123 Statement of Professional Qualifications of Bryce Lehman (NRC003); NRC Testimony at A.1b, A.2b, A.3b (NRC001-R).

124 NRC Testimony at A.3b (NRC001-R).

125 Statement of Professional Qualifications of George Thomas (NRC004); NRC Testimony at A.1c, A.2c, A.3c (NRC001-R).

126 NRC Testimony at A.3c (NRC001-R).

31 Regulatory Research (RES), at the NRC.127 Mr. Philip is the project manager of the RES research project, Structural Performance of Nuclear Power Plant (NPP) Concrete Structures Affected by Alkali Silica Reaction (ASR) being conducted at the National Institute of Standards and Technology (NIST). He served as the primary reviewer for RESs independent review of the LAR, as requested by NRR.128

60.

Based on the above, we conclude that the NRC Staffs witnesses collectively are qualified through knowledge, skill, directly-relevant experience, training, and education to provide expert witness testimony on the topics of: (1) ASR; (2) structural engineering, testing and analysis; (3) nuclear regulation and licensing; (4) NextEras LAR (including the LSTP, the SMP, and the SEM); (5) Seabrooks seismic Category I structures; (6) the NRCs oversight of NextEras ASR-related activities and review of the LAR; and (7) and consensus codes for structural evaluation.

(3)

C-10s Expert Witness

61.

Dr. Victor Saouma is a Professor of Civil Engineering at the University of Colorado in Boulder, the Managing Partner of consulting firm XElastica, LLC, and a Professeur des Universités in France.129 He has conducted theoretical, numerical (deterministic/probabilistic, static/dynamic), and experimental (material and structural) research related to ASR, and developed his own predictive model. He has conducted research for various government agencies, and written peer-reviewed articles on various engineering topics, including 127 Statement of Professional Qualifications of Jacob Philip (NRC006); NRC Staff Testimony of Jacob Philip at A.1-A.3 (RES Testimony).

128 RES Testimony at A.2-A.3 (NRC005).

129 Curriculum Vitae, Dr. Victor E. Saouma (INT003); Pre-Filed Opening Testimony of Victor E. Saouma, Ph.D.

Regarding Scientific Evaluation of NextEras Aging Management Program for Alkali-Silica Reaction at the Seabrook Nuclear Power Plant, Submitted on Behalf of C-10 Research and Education Fund § A.1 (Saouma Testimony) (INT001-R).

32 ASR. Dr. Saouma has provided consultation services related to fracture mechanics, and is the chair of a RILEM (also known as International Meeting of Laboratories and Experts of Materials, Construction Systems and Structures) committee on Diagnosis and Prognosis of ASR affected Structures.130

62.

Based on the above, we conclude that C-10s witness is qualified through knowledge, skill, directly-relevant experience, training, and education to provide expert witness testimony on the topics of: (1) ASR; and (2) structural engineering, testing and analysis, excluding anchors and reinforcement anchorage. We find that Dr. Saouma disavowed any expertise related to anchors and reinforcement anchorage,131 and is unfamiliar with NRC licensing and regulation.132 We also find that Dr. Saouma has not demonstrated sufficient expertise or factual knowledge regarding Seabrooks seismic Category I structures (including their structural design and applicable codes, standards, and regulations), the LAR and its various components (i.e., the LSTP, SMP, and SEM), or the NRCs oversight of NextEras ASR-related activities and review of the LAR, because there exists no evidence in the record that he reviewed the majority of the documentation related thereto.133 We further find that Dr. Saouma is not licensed for the practice of engineering anywhere in the United States (or elsewhere),134 and therefore is not qualified to provide expert witness testimony on engineering practice.

130 Saouma Testimony at A.3 (INT001-R).

131 Tr. at 674 (Dr. Saouma: I confess full ignorance about anchors); id. at 675 (Dr. Saouma noting he is not in a position to present any testimony to contradict NextEras evidence regarding the LSTP anchor testing); id. at 435 (Dr. Bayrak noting that Dr. Saouma confirmed reinforcement anchorage was outside his area of expertise); id. at 266 & Tr. Corr. at 4 (Dr. Saouma: I dont claim expertise on anchorage).

132 Tr. at 365-66 (C-10s counsel interrupting the evidentiary hearing to advise the Board that Dr. Saouma is unfamiliar with common NRC terminology, concepts, and acronyms).

133 Saouma Testimony § A.5 (INT001-R); Rebuttal Testimony of Victor E. Saouma, Ph.D Regarding Scientific Evaluation of NextEras Aging Management Program for Alkali-Silica Reaction at the Seabrook Nuclear Power Plant § A.7 (Aug. 23, 2019) (Saouma Rebuttal) (INT028).

134 Saouma Rebuttal § A.3 (INT028) (I am not a licensed P[rofessional ]E[ngineer]).

33 B.

Technical Background on ASR and Structural Adequacy

63.

The UFSAR for a nuclear power plant includes references to certain structural criteria, including industry consensus codes and standards, that specify means for determining and confirming the structural adequacy of structures for both existing structures135 and the design of new structures. These codes, developed by consensus committees of leading structural engineering experts (e.g., the ACI and ASME), are NRC-reviewed and endorsed, impose mandatory legal requirements on NextEra, contain inherent margins of conservatism, and have been proven to contain safe and conservative structural analysis methods and acceptance criteria based on decades of actual experience around the world.

64.

Evaluations of structural adequacy under these codes and standards determine whether the demands (i.e., load effects) on a structure exceed the capacities (e.g., strength or stress limits) of the structure.136 Methods of determining appropriate demands and capacities are likewise prescribed by the specific criteria, standards, and codes; and these methods typically include consideration of material properties.137 There are many types of loads that may be specified in UFSARs for use in structural adequacy calculations. Examples are dead loads (the fixed weight of the structure), live loads (such as the time-varying weight of contents, e.g.,

temporary storage of materials), wind, earthquake effects, and temperature effects.138 However, these codes do not purport to include a prescriptive list of all loads that must be evaluated.139 135 MPR Testimony at A31 (NER001); SGH Testimony at A36 (NER004); NRC Staff Testimony at A12 (NRC001-R).

136 SGH Testimony at A37 (NER004).

137 Id. At Seabrook, these methods are described in its UFSAR at Section 3.8.

138 Id. at A51.

139 Tr. at 577-79; 1004-05.

34 Rather, they anticipate that any additional loads (i.e., those not explicitly enumerated in the minimum list of loads in the code equation) will be added as necessary.140

65.

ASR is a chemical reaction that manifests over the course of many years (or decades) and occurs in concrete when particular silica-containing constituents of aggregate react with hydroxyl ions and alkali ions (e.g., sodium, potassium) from the cement or another source (e.g., salt).141 The reaction produces an alkali-silicate gel that expands as it absorbs moisture, exerting tensile stress on the surrounding concrete and resulting in cracking.142 The initial indication of ASR is usually the presence of pattern cracking on the concrete surface of the affected structure that prompts further evaluation.143 In the case of ASR, this cracking is usually a network of very fine cracks that may appear to form a pattern or look like a map - hence the terms pattern cracking and map cracking as typical ASR symptoms.144

66.

Because ASR produces cracking in concrete, it eventually causes degradation of its material properties when these properties are tested in typical small, unrestrained laboratory specimens or extracted cores.145 However, in actual, larger, reinforced concrete, like that used at Seabrook, the embedded reinforcing bars resist ASR-caused expansion, which results in a chemical prestressing effect.146 This chemical prestressing effect produces a benefit to the 140 Id.; Am. Concrete Inst. (ACI) Standard 318-71, Building Code Requirements for Reinforced Concrete §§ 8.21, 9.3.2, 9.3.7 (1970) (ACI 318-71) (NRC049).

141 MPR Testimony at A65, A73 (NER001); NRC Testimony at A5, A8 (NRC001-R).

142 MPR Testimony A65 (NER001); see also MPR-4273 § 1.2.1 (July 2016) (INT019 (NP), INT021 (P)).

143 MPR Testimony at A72 (NER001); see also Inst. of Structural Engrs, Structural Effects of Alkali-Silica Reaction, § 6 at p. 19 (July 1992) (ISE Guideline) (NER012) and U.S. Federal Highway Admin., Report on the Diagnosis, Prognosis, and Mitigation of Alkali-Silica Reaction (ASR) in Transportation Structures, FHWA-HIF-09-004, § 1 at p.1 (Jan. 2010) (FHWA Guideline) (NER013).

144 MPR Testimony at A72 (NER001); ISE Guideline § 6 at p. 19 (NER012); FHWA Guideline § 1 at p. 1 (NER013).

145 MPR Testimony at A68 (NER001).

146 MPR Testimony at A68 (NER001); SGH Testimony at A54 (NER004).

35 structural performance of concrete in some limit states (e.g., shear) and results in no degradation to others (e.g., flexure, reinforcement anchorage)until the concrete reaches an excessive level of ASR-related expansion.147 In other words, the chemical prestressing effect causes the structural performance of ASR-affected reinforced concrete to be better than what one might expect if merely using the material properties of unrestrained ASR-affected concrete in calculations prescribed in existing consensus codes and standards.148

67.

Furthermore, ASR-related expansion of restrained concrete can produce new demands (i.e., loads) on the structure.149 Absent internal or external restraint, ASR expansion will cause concrete to expand freely, and no loads are developed. However, if the concrete is restrained internally (such as by reinforcing steel), the restraint will create compressive load in the concrete and tension in the reinforcement.150 Likewise, when ASR-affected concrete is restrained externally (e.g., by bedrock), compressive load will be generated in the ASR-expanded concrete and in the external restraining element.151 C.

Motions in Limine

68.

On September 9, 2019, pursuant to 10 C.F.R. §§ 2.1204, 2.319, 2.323, 2.337, and in accordance with the Boards Initial Scheduling Order,152 NextEra filed the Second MIL, which timely moved to strike or exclude from the record portions of the testimony and exhibits 147 MPR Testimony at A68 (NER001).

148 Id.

149 MPR Testimony at A67 (NER001); SGH Testimony at A53 (NER004).

150 MPR Testimony at A68 (NER001); SGH Testimony at A54 (NER004).

151 SGH Testimony at A53 (NER004).

152 ASLB, Initial Scheduling Order (Nov. 29, 2017) (unpublished) (ML17333A981) (ISO). See also ASLB, Memorandum and Order (Revised Scheduling Order) at 2 n.9 (Feb. 15, 2018) (unpublished) (ML18046A985)

(revising certain milestone dates but stating [t]he remainder of the Initial Scheduling Order continues to be in effect).

36 offered by C-10 that are irrelevant, immaterial, unduly cumulative, beyond the scope of the Contention admitted by the Board in LBP-17-7, or beyond the permissible scope of rebuttal testimony.153 NextEra also filed the First MIL on April 23, 2019.154 The Board initially deferred ruling on both motions.155 The Second MIL essentially expands upon, incorporates by reference, and supersedes arguments raised in the First MIL. Thus, the Boards ruling pertains to NextEras Second MIL.

69.

As explained further below, portions of C-10s Testimony and exhibits fail to present probative evidence relevant or material to the limited Contention being adjudicated in this proceeding. Thus, the Board grants NextEras Second MIL and strikes from the evidentiary record those portions of the Testimony and exhibits listed below.

(1)

Previously-Rejected Arguments and Extraneous Topics

70.

Steel Corrosion: In proposed contention F, C-10 alleged that elevated levels of salt... [have] likely created the conditions for corrosion of reinforcing steel.156 In LBP-17-7, the Board rejected that argument and denied proposed contention F as outside the scope of the LAR because the corrosion degradation mechanism is covered by an entirely separate monitoring program at the plant.157 However, C-10 has submitted testimony from Dr. Saouma which attempts to advance arguments regarding this excluded topic.158 Because these statements 153 Second MIL.

154 First MIL.

155 Order on First MIL; Order on Second MIL.

156 Petition at 12.

157 Seabrook, LBP-17-7, 86 NRC at 132-33. See also Seabrook Structures Monitoring Program Manual, Rev. 7 at ch. 6 § 1.3 (SMPM) (NER007).

158 Saouma Testimony at 21 (INT001-R); Rebuttal Testimony at 36 (INT028) (arguing NextEra should test for chloride concentration to monitor rebar corrosion).

37 simply reiterate the argument previously rejected by the Board, they are stricken from the record.159

71.

Point of Failure and Alternative Means of Regulatory Compliance: In proposed contention G, C-10 argued that the LAR was deficient because it did not include a methodology to test materials up to and beyond their point of failure.160 But as the Commission has long recognized, a finding of reasonable assurance can be made even though other data and methods might have been used.161 Thus, the mere presentation of an alternative method of regulatory compliance is irrelevant to the question of whether the method presented by the applicant satisfies regulatory requirements. In LBP-17-7, the Board rejected C-10s impermissible attempt to require the use of a specific methodology, and denied the proposed contention as immaterial to the findings the Staff must make to issue the amendment.162 Nevertheless, C-10 presented testimony and exhibits for the purpose of arguing that NextEra should have used specific alternative methodologies, including the use of accelerated testing and predictive methodologies capable of identifying the point of failure.163 But these arguments already have been excluded from this proceeding, and therefore are irrelevant and 159 Saouma Testimony at 21, last sentence, beginning Because of the proximity...; Rebuttal Testimony

§ D.8.3.

160 Seabrook, LBP-17-7, 86 NRC at 134 (citing Petition at 15).

161 Shoreham, LBP-88-13, 27 NRC at 548, affirmed in part, vacated in part, remanded by ALAB-905, 28 NRC 515 (1988). Cf. Palisades, CLI-15-22, 82 NRC at 317-18 (noting that there may be alternate or alternative methods by which a licensee can demonstrate reasonable assurance).

162 Seabrook, LBP-17-7, 86 NRC at 133-35.

163 See, e.g., Saouma Testimony at 7 (INT001-R) (arguing that the LARs analysis methodology is deficient because it does not capture... the failure load of ASR); id. at 29-30 (advocating the use of specific alternative methodologies, e.g., abandoning code-based analysis in favor of probabilistic analysis, that purportedly could accomplish these Board-excluded objectives); id. at 31-35 (advocating alternative steps for addressing ASR at Seabrook in Section C.6); Tr. at 378-79 (Dr. Saouma arguing NextEra should use accelerated testing and predictive models to find the ultimate expansion) ; V. Saouma, Review of Selected Documents Pertaining to the Structural Evaluation of Seabrook Nuclear Power Plant at 1, 9-19 (Feb. 12, 2019)

(EP Report) (INT031 (NP), INT007 (P)) (advocating alternative methods of analyses).

38 immaterial for the same reasons articulated by the Board in LBP-17-7, and are hereby stricken from the evidentiary record.164

72.

License Renewal: C-10 presented evidence purporting to challenge the sufficiency of NextEras LRA for Seabrook.165 However, the Seabrook LRA is not at issue in this proceeding. Indeed, as the Commission noted in its recent decision rejecting C-10s Emergency Petition, C-10 already had a full and fair opportunity to raise ASR-related contentions in the license renewal proceeding but did not do so.166 The Commission noted that, in order to offer new challenges regarding license renewal, C-10 would need to submit a motion to reopen that proceeding,167 something C-10 also had a full and fair opportunity to, but did not, do. As a practical matter, C-10s concerns in this regard are addressed by the Commissions acknowledgement that any changes resulting from the review of the LAR will be reflected in the license renewal aging management programs.168 But as a matter of law, C-10s license renewal-related arguments cannot be addressed in this proceeding. Accordingly, that evidence is stricken from the record as irrelevant and immaterial.169

73.

Emergency Petition: C-10 also presented arguments and documents from its Emergency Petition, which was rejected by the Commission. Notably, the Commission explicitly stated that the Emergency Petition raises issues... that are beyond [the] scope [of 164 Saouma Testimony §§ B.3, C.3.4.1.1, C.5, C.6, C.7, and C.8; Rebuttal Testimony at 9 (beginning with the first full sentence, NextEra effectively... through the end of the first full paragraph,... used by NextEra) and

§§ A.10, A.11, and A.14; EP Report at 1, sixth para. (beginning, Of equal...) and §§ 5.2 and 6.

165 Saouma Testimony at 36 (INT001-R).

166 NextEra Energy Seabrook, LLC (Seabrook Station, Unit 1), CLI-19-7, 90 NRC __, __ (July 25, 2019) (slip op.

at 2, 7) (ML19206A427).

167 Id. at __ (slip op. at 10-11).

168 Id. at __ (slip op. at 14) (citing Safety Evaluation Report Related to the License Renewal of Seabrook Station § 3.0.3.3.6 at 3-228 (Sept. 28, 2018) (SER) (ML18362A370)).

169 Saouma Testimony at 9, second full para. (beginning It is important...) and § C.10.

39 this LAR proceeding].170 Nevertheless, C-10 submitted as exhibits the full set of documents prepared by Dr. Saouma in support of the Emergency Petition, including his declaration (INT006), Emergency Petition Report (EP Report) (INT007)(P) and non-proprietary EP Report summary (INT008), and reply declaration (INT009). But there is no discernable basis to import C-10s rejected arguments from the Emergency Petition into this proceeding. Moreover, the content of the EP Report is largely duplicative of Dr. Saoumas Testimony.171 Thus, in addition to being irrelevant and immaterial, this information also is unduly repetitious, duplicative, and cumulative,172 and is stricken from the record.173

74.

Peer Review: In its testimony, C-10 raised an argument alleging NextEra failed to conduct an adequate peer review.174 But this is an entirely new175 argument that could have been, but was not, raised at the outset of this proceeding.176 This distinctly new argument which is unrelated to the representativeness of the LSTPwas not included in the Contention, as pled and admitted, and therefore is stricken from the evidentiary record.177 170 Seabrook, CLI-19-7, 90 NRC at __ (slip op. at 6-7).

171 Compare EP Report § 5.3 (INT007)(P) with Saouma Testimony § C.3.4.1 (INT001-R) (both containing nearly identical arguments purporting to challenge Rev. 0 of the structural evaluation for the Containment Enclosure Building (Rev. 0 CEB Evaluation)).

172 See 10 C.F.R. §§ 2.337(a), 2.319(e).

173 Saouma Testimony § C.1 (INT001-R); Declaration of Dr. Victor E. Saouma, Ph.D (Feb. 12, 2019) (INT006),

EP Report (INT008 (NP), INT007 (P)); Reply Declaration of Victor E. Saouma, Ph.D (Mar. 1, 2019)

(INT009).

174 Saouma Testimony § C.9 (INT001-R).

175 Proposed contention E challenged NextEras use of proprietary information, arguing it purportedly prevented an independent assessment of the test results and was not good science because peer review allows for scientific consensus. Petition at 11. Dr. Saoumas assertion is materially different, and therefore new.

Nevertheless, even if the two arguments somehow could be viewed as related, Dr. Saoumas argument would be inadmissible because the Board rejected Proposed contention E altogether. Seabrook, LBP-17-7, 86 NRC at 131-32.

176 Moreover, if C-10 had raised this issue at the outset, it would have been rejected as immaterial (because there is no requirement for peer review in 10 C.F.R. Part 50) and as demonstrably unsupported given the evidence of various independent sources of input and review (see supra ¶ 18).

177 Saouma Testimony at 9, first para. (beginning, I also have...) and § C.9; Rebuttal Testimony, § B.6.

40 (2)

New Challenges to the LSTP

75.

Expanded Bases Regarding LSTP Representativeness: In LBP-17-7, the Board found admissible a portion of Contention D challenging the representativeness of the concrete specimens tested in the LSTP as compared to the condition of Seabrooks concrete on the basis that Seabrook structures have existed for a long duration of time and have been subjected to environmental and operational conditions not replicated in the LSTP. More specifically, C-10 alleged non-representativeness due to the following characteristics: age; length of time ASR has propagated; exposure to fresh water at various levels; exposure to salt in the water at different levels and concentrations; the effects of heat; and the effects of radiation.178 In simplified terms, the basis for the contention was the alleged contrast between an older exposed structure versus newer test specimens.

76.

As noted above, C-10 proffered comment letters from Dr. Brown to support its original bases. At the hearing stage, C-10 instead relied on Dr. Saouma, whose testimony did not address the above list of age-and exposure-related characteristics. Instead, Dr. Saouma newly argued that the LSTP specimens were not representative of Seabrook due to alleged differences in (1) the LSTPs concrete mixture design, and (2) the LSTPs specimen scale and reinforcement design. In fact, C-10 originally recognized NextEras great effort to obtain the appropriate concrete mix, but noted that its concern was focused on something else altogetherthe alleged lack of clear definition for the level of representativeness to be obtained in the LSTP regarding its list of age-and exposure-related characteristics.179 178 Seabrook, CLI-18-4, 87 NRC at 104 (citing Petition at 11).

179 Petition at 9.

41

77.

Although Dr. Saoumas new arguments are broadly related to the Contentions key subject of representativeness, the Board is required by law to interpret contentions as being enveloped by their original bases.180 The Commission has long held that intervenors may add additional bases within the envelope of the original bases as the proceeding progresses.181 Thus, it would have been permissible for C-10 to proffer additional age-and exposure-related arguments, beyond the list in the original Petition. However, we find no evidence that Dr.

Saoumas new arguments on aggregate selection and specimen scale (including reinforcement design) are related to the original basis for the contentionthe allegedly unique in situ aging and exposure characteristics at Seabrook. Thus, the Board strikes these arguments182 from the evidentiary record.183

78.

New Challenges to LSTP Experimental Design: Likewise, Dr. Saouma raises a host of new issues and challenges related to the design and execution of the LSTP that could have been, but were not, raised at the outset of this proceeding. For example, he challenges the boundary conditions used in the LSTP, the lack of in-plane shear testing in the experimental design, and the alleged lack of discussion of cracking and load displacement in the test reports.184 But the Board finds no evidence that these arguments on the experimental design of the testing program are related to the original basis for the contentionthe allegedly unique in situ aging 180 Entergy Nuclear Generation Co. (Pilgrim Nuclear Power Station), CLI-10-11, 71 NRC 287, 309 (2010) (citing Seabrook, ALAB-899, 28 NRC at 97 (1988), affd sub nom. Massachusetts v. NRC, 924 F.2d 311 (D.C. Cir.),

cert. denied, 502 U.S. 899 (1991)).

181 La. Energy Servs., LP (National Enrichment Facility), CLI-04-35, 60 NRC 619, 623 (2004); Duke Energy Corp. CLI-02-28, 56 NRC at 379 (citations omitted).

182 Saouma Testimony §§ C.2.1, C.2.2 (INT001-R).

183 Accord Fla. Power & Light Co. (Turkey Point Units 6 & 7), Memorandum and Order (Ruling on Motions to Strike or Exclude) (Mar. 15, 2017) (ML17074A581) (striking new bases generally related to the admitted contention but outside the envelope of the original bases).

184 Notably, Dr. Saouma later withdrew his challenge regarding cracking and load displacement, noting he simply missed the appropriate information in the testing documentation. Tr. at 314.

42 and exposure characteristics at Seabrook. Thus, the Board strikes these arguments185 from the evidentiary record.186 (3)

New Challenges Regarding Seabrook Structural Evaluations

79.

As explained in greater detail below in Section IV.F., the evidence shows that Seabrooks UFSAR specifies the method NextEra must use to evaluate the structural adequacy of seismic Category I structures at Seabrook (the Structural Evaluations). A Structural Evaluation compares the demands (i.e., load effects) on a structure to the capacities (e.g.,

strength or stress limits) of the structure to ensure the structure complies with the plants licensing basis (i.e., can continue to perform its intended safety function).187 The LAR included a methodology for performing these Structural Evaluations on Seabrooks structures (i.e., the SEM). The SEM employs Seabrooks existing codes (i.e., no change from the existing UFSAR),

and existing capacity values (i.e., no change from the existing UFSAR), but uses demand values that consider new ASR loads and load factors calculated from field data at Seabrook (i.e., a change to the existing UFSAR).188 Notably, the evidence shows that no values from the LSTP are inputs to the Structural Evaluations.189

80.

Dr. Saoumas original testimony challenged NextEras treatment of ASR as a load on the structure, and its process for calculating those loads and load factors.190 But the 185 Saouma Testimony §§ C.2.2, C.2.3.1, C.2.3.2 (INT001-R).

186 Accord Fla. Power & Light Co. (Turkey Point Units 6 & 7), Memorandum and Order (Ruling on Motions to Strike or Exclude) (Mar. 15, 2017) (ML17074A581) (striking new bases generally related to the admitted contention but outside the envelope of the original bases).

187 MPR Testimony at A37 (NER001).

188 SGH Testimony at A57 (NER004).

189 Id. at A40.

190 Notably, Dr. Saouma later withdrew his challenge regarding the ASR loads and load factors, ultimately salut[ing] NextEras development of this approach in conjunction with Dr. Ellingwood. Tr. at 440-41; Saouma Rebuttal § A.12 (INT028).

43 evidence demonstrates that SGH developed the approach of calculating ASR loads and load factors independent of the LSTP.191 Thus, the loads and load factors would not be impacted either way by any alleged non-representativeness of the LSTP. As such, these arguments are irrelevant and immaterial to the admitted Contention. Accordingly, we strike these arguments as beyond the scope of the Contention.

81.

The Board finds the evidence also shows that NextEras decision to continue using original capacity values in the Structural Evaluations was at least partly driven by a conclusion from the LSTP that this approach was valid. Accordingly, we decline to strike C-10s challenge to the SEMs use of original capacity values, but only to the extent that challenge relates to the representativeness of the LSTP. C-10 presents no evidence that its broader theoretical challenge to NextEras use of original capacity valuesi.e., arguing that this approach improperly conflates material properties and structural propertiessomehow is related to the representativeness of the LSTP.192 Accordingly, we strike those portions of C-10s challenge.

82.

We also find that Dr. Saoumas criticisms of one specific Structural Evaluation namely, the Rev. 0 CEB Evaluation193are outside the scope of this proceeding. NextEra did not request approval of (and the NRC did not approve) any individual Structural Evaluations as part of the LAR. Thus, as a general matter, Dr. Saoumas criticisms are beyond the scope of the LAR and this proceeding. Furthermore, the Rev. 0 CEB Evaluation was subsequently updated by NextEra. Thus, C-10s challenges pertain to an outdated document, and C-10 presented no 191 SGH Testimony at A40 (NER004).

192 The plain language of the Contention, by its own terms, makes clear that challenges to the LAR must purport to be the result of the alleged non-representativeness of the LSTP.

193 See Saouma Testimony § C.3.4.1 (INT001-R) (discussing Rev. 0 CEB Evaluation (INT015)).

44 evidence to demonstrate that its criticisms of the outdated document would be material to this proceeding even if the individual Structural Evaluations could be challenged here. Thus, these challenges also must be rejected as immaterial. And finally, Dr. Saoumas various criticisms of the Rev. 0 CEB Evaluation go well beyond the representativeness of the LSTP. For example, Dr. Saouma criticizes SGHs use of shell elements, thermal expansion to simulate ASR expansion, and section cuts in the finite element model (FEM) software, and the method of seismic evaluation (i.e., stick model) that is already specified in Seabrooks existing license.194 But these aspects of the SEM are entirely unrelated to the representativeness of the LSTP.

Thus, we strike Dr. Saoumas challenges to the Rev. 0 CEB Evaluation for this third reason.

(4)

Impermissible Rebuttal

83.

C-10s rebuttal testimony addressed numerous issues that could have been, but were not, raised in C-10s case-in-chief, or that otherwise expand on earlier arguments without purporting to rebut any evidence by NextEra or the NRC Staff. But parties may not unilaterally use rebuttal to add cumulative evidence to bolster their original case because the scope of proper rebuttal is narrow, and limited to actually rebutting new and unforeseeable arguments presented by the other parties.

84.

More specifically, C-10s rebuttal supplied new information in rebuttal to bolster its initial testimony regarding Dr. Saoumas professional qualifications, relative humidity, and structural cracking, and a new cancer analogy.195 The record shows that none of these arguments even purport to rebut NextEras or NRC Staffs testimony. Thus, they are beyond the scope of permissible rebuttal and are stricken from the record.

194 Id.

195 Saouma Rebuttal at §§ A.2, A.9, D.6, and D.7 (INT028).

45

85.

Other portions of C-10s rebuttal purport to rebut certain quotes or statements in NextEras or NRC Staffs testimony. But the record evidence in this proceeding demonstrates that those quotes and statements do not qualify as unforeseen arguments. Rather, they are simple summaries or restatementssometimes verbatimof information in the LAR or the NRC Staffs Safety Evaluation (SE), which have been available to C-10 for many months or years. C-10 offers no explanation why it could not have challenged the various features of the LAR, and conclusions in the SE, at that time. C-10s untimely challenges to these features and conclusions pertain to: Use of ACI 318-71 (Section B.4); Interim Assessment (Section D.1.1);

Probabilistic Features in LAR (Section D.1.2); Load Testing (Section D.3.2); Seismic Response and Flexural Stiffness (Section D.4.2); Validation of Strain with Field Measurements (Section D.8.2); Corroboration Study and Empirical Correlation (Section D.9.1 and Supplemental Rebuttal (INT030); ASR Load Inputs (Section D.9.2); Design Basis Concrete Properties (Section D.9.3); and Seismic Uncertainty (Section D.9.4). We find that each of these arguments by C-10 could have been raised based on information available prior to its deadline for filing initial testimony, and that none of these arguments respond to an unforeseeable argument advanced by NextEra or NRC Staff in their testimony.196 Accordingly, they are beyond the scope of permissible rebuttal and stricken from the proceeding.

D.

The LSTP

86.

NextEra deliberately designed the LSTP to provide test data on structural performance of large-scale test specimens that were more representative of concrete from 196 A detailed chart correlating C-10s untimely rebuttal arguments to specific portions of the LAR or SE available to C-10 prior to its initial testimony deadline is found in the Second MIL at 29-31. We incorporate that chart here by reference.

46 Seabrook than data that were publicly available in the literature.197 The LSTP specifically addressed selected limit states through testing programs for: (1) one-way shear (i.e., beam shear),

(2) reinforcement anchorage, and (3) anchor capacity.198 Because monitoring through-thickness expansion was deemed necessary for long-term aging management of ASR-affected reinforced concrete at Seabrook, and no consensus technique for accomplishing through-thickness monitoring was available in industry guidance, a fourth testing program for evaluating and selecting instrumentation was added to the LSTP.199

87.

The LSTP was performed at the FSEL of The University of Texas at Austin over a period of approximately four years.200 The LSTP itself was performed due to the absence of large-scale test data related to the impact of ASR on highly reinforced concrete members. FSEL was selected because of its long history of world-class research using large-scale test specimens, its experience with concrete and degradation by ASR, and its experience with fabrication of concrete test specimens that develop ASR in an accelerated manner necessary for testing.201 The development, execution, and review of the LSTP were supplemented by multiple non-NextEra personnel and organizations, as noted in paragraph 15, above.

88.

MPR prepared test reports and documentation regarding the Commercial Grade Dedication efforts (CGD, i.e., the formal process based on NRC regulatory requirements for ensuring quality of services obtained from commercial suppliers for application at a nuclear 197 MPR Testimony at A97 (NER001) (citing MPR-4273 §§. 1.2.2 & 2.3.4 (INT019-R (NP), INT021 (P)).

198 Id.

199 Id. Specific and extensive details regarding the four structural testing programs are provided in the record id.

at A137-A142 (Shear Test Program); A143-A149 (Reinforcement Anchorage Test Program); A150-A155 (Anchor Test Program); A156-A157 (Instrumentation Test Program).

200 Id. at A98. See also Final SE at §3.1.2 (INT024 (NP), INT025 (P)).

201 MPR Testimony at A98 (NER001).

47 plant)202 throughout the course of the LSTP.203 Table 1 below summarizes these various reports, the total page count of which is approximately 24,000 pages.204 To distill this information into a format that was more readily usable, MPR prepared MPR-4273 (INT019 (NP), INT021(P)) and MPR-4288 (INT012 (NP), INT014(P)), which summarize the LSTP, its conclusions, and the implications for Seabrook.

Table 1. Summary of MPR Reports for LSTP Test Program Test Reports CGD Reports Anchor MPR-3722 MPR-3726 MPR-4247 MPR-4286 Shear MPR-4262 MPR-4259 MPR-4286 Reinforcement Anchorage Instrumentation MPR-4231

89.

The various test programs in the LSTP were designedfrom the outsetwith representativeness to Seabrook concrete in mind. The LSTP explicitly endeavored to, and did, satisfy representativeness objectives including:

Large specimen size to represent the scale of structures at Seabrook;205 Experimental design that is accepted by the concrete industry in, and as the basis for, published Codes and consistent with the design basis of Seabrook;206 202 Id. at A100.

203 Id. at A99.

204 Id.

205 Id. at A102-A105; Tr. at 635-36.

206 MPR Testimony at A106-A108 (NER001).

48 Specimen design that uses a reinforcement configuration and concrete mixture design that sufficiently reflects reinforced concrete structures at Seabrook;207 and Presence of ASR to an extent that is consistent with levels currently observed at Seabrook and at levels that could be observed in the future.208

90.

Each of the four test programs were governed by a written and approved Test Specification that included provisions to ensure the objectives described above were achieved.209 And critical characteristics of the test specimens and setup necessary to ensure satisfaction of the representativeness objectives were evaluated as part of CGD activities.210

91.

The test reports211 provide technical justifications for representativeness of the specimens; and critical characteristics were included in the commercial grade acceptance plans for the test programs.212 As documented therein, all parameters met the acceptance criteria, which supported the ultimate conclusion that the test specimens were sufficiently representative of Seabrook in order to meet the established purposes of the LSTP.213 207 Id. at A109-A114; Tr. at 635.

208 MPR Testimony at A115-125 (NER001).

209 Id. at A101. The test specifications are included as appendices in the respective test reports: See MPR-3722, Rev. 2, Strength Testing of Anchors in Concrete Affected by Alkali-Silica Reaction (Jan. 2016) (FP100718, Rev. 1) (MPR-3722) (NER023); MPR-4262, Shear and Reinforcement Anchorage Testing of Concreted Affected by Alkali-Silica Reaction, Vol. I, Rev. 1 (July 2016) & Vol. II, Rev. 0 (Jan. 2016) (FP100994)

(MPR-4262) (NER022-R); and MPR-4231, Rev. 0, Instrumentation for Measuring Expansion in Concrete Affected by Alkali-Silica Reaction (Oct. 2015) (FP100972) (MPR-4231) (NER021).

210 MPR Testimony at A99, A100, A101 (NER001).

211 MPR-3722 (NER023); MPR-4262 (NER022-R); MPR-4231 (NER021).

212 MPR-4259, Commercial Grade Dedication Report of Seabrook ASR Shear, Reinforcement Anchorage and Instrumentation Testing App. B (Jan. 2016) (MPR-4259) (NER025-R); MPR-4247, Rev. 0, Commercial Grade Dedication Report for Seabrook ASR Anchor Testing (Block Series and Girder Series Phase 2) App. B (Dec. 2015) (FP100986) (MPR-4247) (NER024); MPR-4286, Rev. 0, Supplemental Commercial Grade Dedication Report for Seabrook ASR Test Programs (Mar. 2016) App. B (FP101003) (MPR-4286)

(NER045).

213 Id.

49

92.

Multiple methods were used to characterize ASR development in the test specimens including:

expansion monitoring by physical measurements of the specimens (e.g.,

crack width summation, embedded rods);

material property testing of cores removed from the specimens; and petrographic examinations of cores removed from the test specimens.214

93.

Ultimately, NextEra identified expansion monitoring as the appropriate parameter for correlating the LSTP results to Seabrook, consistent with the approach advocated by industry guidance, as discussed in MPR-3848.215 Expansion monitoring, as used in the LAR methodology, entails collection of measurements for in-plane expansion (e.g., crack-width measurements) and through-thickness expansion (i.e., extensometer measurements) for monitoring against acceptance criteria for in-plane, through-thickness, and volumetric expansion.

This approach is objectively reasonable because expansion is the parameter of interest for the aging effect in questionstructural performance of ASR-affected structures.216 Expansion monitoring is also a practical solution for implementation in a nuclear power plant, given the number, variety and large dimensions of the affected or potentially-affected concrete structures.217 Furthermore, as indicated by the LSTP, crack width indexing and extensometers provide reliable and accurate measures of in-plane and through-thickness expansion; and the combination of these values provide a reliable and accurate measure of volumetric expansion.218 214 MPR Testimony at A126; see also MPR-4273 § 4.1 (INT019 (NP), INT021 (P)).

215 MPR Testimony at A126 (NER001); see also MPR-3848 § 2.2.2. (NER015).

216 MPR Testimony at A126 (NER001).

217 Id.

218 Id. at A130, A170, A177, A217, A222 (NER001).

50

94.

The LSTP demonstrated that the specified material properties of concrete from the original design calculations may be used to calculate the capacity of selected limit states (i.e.,

flexural and shear capacities and anchorage of reinforcing bars) of ASR-affected structures using the existing design codes specified in the UFSAR, provided that observed and monitored expansion at Seabrook is below the levels of expansion witnessed during the LSTP (i.e., the Expansion Monitoring Limits). NextEra monitors Seabrooks structures against these Expansion Monitoring Limits through implementation of a comprehensive and robust SMP.219

95.

We find that a preponderance of the evidence demonstrates that the LSTP yielded data that are appropriate for use to represent the structural performance of the ASR-affected concrete structures at Seabrook, and that reasonable assurance exists for the NRC Staff to grant the LAR. Furthermore, as explained below, we find that C-10s criticisms of the LSTP do not defeat a finding of reasonable assurance.

96.

Notably, C-10 only presented probative evidence purporting to challenge one of the four testing programs performed as part of the LSTP: namely, the shear (aka one-way shear or beam shear) program. C-10s expert explicitly acknowledged that he was not qualified to testify in the areas of reinforcement anchorage and anchor capacity.220 And C-10s expert was not aware of the existence of the instrumentation testing program,221 and therefore did not provide any testimony purporting to counter NextEras evidence regarding the sufficiency of that 219 Id. at A138.

220 Tr. at 674 (Dr. Saouma: I confess full ignorance about anchors); id. at 675 (Dr. Saouma noting he is not in a position to present any testimony to contradict NextEras evidence regarding the LSTP anchor testing); id. at 435 (Dr. Bayrak noting that Dr. Saouma confirmed reinforcement anchorage was outside his area of expertise); id. at 266 & Tr. Corr. at 4 (Dr. Saouma: I dont claim expertise on anchorage).

221 Tr. at 1042 (Dr. Saouma suggesting extensometers had been deployed in the field at Seabrook without first having been tested and validated in the laboratory); id. at 1043 (Mr. Simons describing the instrumentation testing program and confirming Judge Trikouross statement that extensometers were verified in the test program); MPR-4231 (NER021).

51 program. Thus, the preponderance ofand indeed onlyprobative record evidence demonstrates that the other three testing programs (i.e., reinforcement anchorage, anchor capacity, and instrumentation) yielded data that are appropriate for use to represent ASR-affected concrete at Seabrook, and that reasonable assurance exists as to these program elements.

97.

Additionally, C-10 did not purport to challenge the appropriateness of NextEras representativeness objectives detailed above, or the LSTPs satisfaction thereof under a formal nuclear QA program.222 Indeed, C-10s expert acknowledged that a reasonable reviewer could view the LSTP as being representative of Seabrook based on NextEras approach.223 However, C-10s expert also acknowledged that he is particularly finicky, and that his subjective standard for representativeness is at the far end of the spectrum.224 Thus, to satisfy his personal standard, C-10s expert argued that NextEra should have selected and satisfied additional representativeness parameters.225 But C-10 presented no evidence to reconcile its experts admittedly finicky standard with the legal standard applicable to the LAR in this proceedingthe reasonable assurance standard. As noted above, the reasonable assurance standard does not require an applicant to meet an absolute or beyond a reasonable doubt standard,226 and has long been interpreted to acknowledge that some risks may be tolerated and something less than absolute protection is required.227 222 See generally MPR Testimony at A197 (NER001).

223 Tr. at 979-80 (Dr. Saouma agreeing that these parameters of representativeness in the LSTP were fine).

224 Id. at 989.

225 Id. at 979-80 (Dr. Saouma agreeing that these parameters of representativeness in the LSTP were fine).

226 Oyster Creek, CLI-09-7, 69 NRC at 262 n.142; Zion Station, ALAB-616, 12 NRC at 421; N. Anna Envtl.

Coal., 533 F.2d at 667-68 (rejecting the argument that reasonable assurance requires proof beyond a reasonable doubt and noting that the licensing board equated reasonable assurance with a clear preponderance of the evidence).

227 Memorandum from F. Brown to New Reactor Business Line, Expectations for New Reactor Reviews at 4 (Aug. 29, 2018) (ML18240A410).

52

98.

In LBP-17-7, the Board found admissible a portion of Contention D challenging the representativeness of data from the LSTP because it allegedly fails to account for the condition of Seabrook concrete due to the following aging and environmental factors:

age; length of time ASR has been propagated; exposure to fresh water at various levels; exposure to salt in the water at different levels and concentrations; the effects of heat; and the effects of radiation.228 Although C-10 presented evidence purporting to challenge the representativeness of the LSTP data on other grounds, it presented no record evidence regarding these specific aging and environmental factors. Thus, we conclude that C-10 failed to satisfy its burden of going forward on the Contention, as defined by its original bases. In fact, the only evidence presented in this proceeding regarding the original bases for the Contention is that of NextEra.229 Thus, even if C-10 had met its burden of going forward, NextEras position is supported by the preponderance ofand indeed the onlyevidence on these issues.

(1)

Concrete Mixture Design

99.

As noted above, the Board has concluded that the LSTP concrete mixture design was not one of the aging and environmental parameters challenged in the original Contention, and thus C-10s arguments on this topic are outside the scope of this proceeding. Nevertheless, even if those arguments were within scope, a preponderance of the evidence demonstrates that NextEras approach to LSTP concrete mixture design provides reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

228 Seabrook, CLI-18-4, 87 NRC at 104 (citing LBP-17-7, 86 NRC at 113 (Petition at 11)).

229 MPR Testimony at A224-A235 (NER001).

53 100.

NextEras evidence shows that the critical characteristics identified in the LSTP for the concrete mixture design to establish representativeness to the plant were compressive strength, cement type, constituent proportions (e.g., ratio of water to cement, aggregate proportions), coarse aggregate size, coarse aggregate surface roughness, and ratio of coarse aggregate to fine aggregate.230 As explained further below, C-10 contends that NextEras concrete mixture design is not representative because (a) NextEra also should have considered aggregate chemical mineralogy a critical characteristic, and (b) NextEras acceptance criteria for LSTP specimen compressive strength were flawed.

101.

In Section C.2.1 of his testimony, Dr. Saouma claims that the LSTP specimens were not representative of Seabrook because it was not established that the aggregate used in the tests were identical to what was used at Seabrook.231 As a practical matter, the Board notes that the use of identical aggregate was not possible because the quarry from which the aggregate was obtained for Seabrook is no longer operating.232 As the evidence further demonstrates, even 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.233 More importantly, Dr. Saouma did not reference any industry or consensus standardsor any other evidencerequiring such replication.

102.

At the evidentiary hearing, Dr. Saouma explained that his specific concern pertained to the mineralogy of the aggregate, which he broke into two subparts: physical and 230 See MPR-4262 at 4-7 tbl.4-3 (NER022-R); MPR-4259, app. B at B-9 to B-13 (NER025-R).

231 Saouma Testimony § C.2.1 (INT001-R).

232 MPR Testimony at A119, A198 (NER001).

233 Id.

54 chemical.234 By the end of the evidentiary hearing, Dr. Saouma agreed with NextEra that the physical aspects of the LSTP coarse aggregates (e.g., size, roughness, ratio) were representative of Seabrookremarking that there was a very strong similarity among the aggregates.235 Thus, we find that the evidence demonstrates that the physical properties of the LSTP aggregates are appropriately representative of Seabrook.

103.

NextEra explained that chemical mineralogy was not a critical representativeness parameter for the LSTP.236 Consistent with available industry guidance and academic literature (which does not differentiate ASR on the basis of gel chemistry),237 NextEra neither relies on nor credits in its methodology any alleged representativeness of ASR gel chemistry. And even if it were possible to exactly replicate Seabrooks concrete mixture design, meaningful expansion would not occur in a useful timeframe. Thus, NextEra explicitly designed the LSTP specimens to have aggregate that is more reactive than Seabrook to ensure they would expand reasonably quickly (i.e. faster than Seabrook) and thus experience a bounding level of expansion.238 As part of planning for the LSTP, FSEL conducted trial batching and reactivity testing of a variety of concrete mixture designs.239 These tests demonstrated that, regardless of the reactivity of the coarse aggregate, 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 234 See, e.g., Tr. at 1082-83 (explaining that he reviewed the physical mineralogy information (e.g., gradation) in NextEras exhibits and was satisfied with that information, but that he further wanted to review chemical mineralogy information to understand the type of gel).

235 Tr. at 1074.

236 MPR Testimony at A117-A118 (NER001); Tr. at 642 (Dr. Bayrak: were not aiming to model the chemical reaction. This was never an intent).

237 See, e.g., MPR Testimony at A118 (NER001) (noting that published technical reports on structural testing of ASR-affected concrete typically relate structural performance to expansion level, rather than a particular chemical constituent of the ASR gel).

238 Tr. at 644.

239 MPR-4262 § 4.3 (NER022-R).

55 for the LSTP.240 Blending highly reactive coarse aggregate and slow reacting coarse aggregate with highly reactive fine aggregate (aka sand) was necessary to have a representative (with respect to structural performance) concrete mixture that would develop large ASR expansions in a timely fashion. C-10 did not challenge NextEras evidence in this regard.241 104.

Dr. Saouma, however, contends that NextEra should have deemed chemical mineralogy to be a critical representativeness characteristic for the LSTP. Dr. Saoumas argument is that chemical mineralogy influences ASR gel type, which in turn affects the cracking pattern. According to Dr. Saouma, the crack pattern is different if ASR expansion is driven by the sand (which he asserted was the case in the LSTP) versus the coarse aggregate (which he asserted was the case at Seabrook), because expansion driven by sand produces smaller cracks which could be undetectable.242 But when questioned at the evidentiary hearing regarding his basis for asserting that the expansion driver was different between the LSTP and Seabrook (and therefore not representative), Dr. Saouma admitted that it was nothing more than speculation.243 But the Board does not find unsupported speculation persuasive.

105.

Furthermore, even if Dr. Saouma is correct that the LSTP specimens experienced smaller cracks (because expansion in the LSTP specimens was driven more by the sand than the coarse aggregate), we see no reason this would render the LSTP results inadequate. It would simply mean that Seabrooks coarse-aggregate-driven244 cracks will be larger (and more easily 240 MPR Testimony at A198 (NER001).

241 Dr. Saouma did not review MPR-4262 (NER022-R). See Saouma Testimony § A.5 (INT001-R) (listing the materials Dr. Saouma reviewed for the hearing, but excluding MPR-4262).

242 Tr. at 604, 1001-02.

243 Tr. at 605 (Judge Spritzer: What is the basis for your saying that the aggregate is more important than the sand at Seabrook? Dr. Saouma: Thats a speculation.)

244 Tr. at 604 (Dr. Saouma: I believe that, at Seabrook, it's mostly the aggregate and not the sand which is the primary driving force).

56 detectible), and that the LSTP results were conservative because, for the same measured crack width index, there could be more degradation in the LSTP specimens (due to allegedly-unobserved small cracks) than in concrete measured in the field at Seabrook.

106.

Dr. Saouma also provided contradictory testimony as to whether chemical mineralogy (i.e., ASR gel type) truly is a critical parameter for representativeness. More specifically, Dr. Saouma testified that it is entirely acceptable, appropriate, and commonplace to alter ASR gel chemistry to accelerate expansion.245 In other words, Dr. Saouma acknowledges that ASR gel chemistry representativeness can be ignore[d] if the purpose of the alteration is to accelerate expansion.246 Indeed, Dr. Saouma has done so in his own research.247 107.

Furthermore, matching the LSTP ASR gel chemistry exactly with the reference location at Seabrook would have rendered the concrete mixture as slow reacting as Seabrook concrete. This result would be incompatible with NextEras need to obtain timely and useful test data to develop an ASR program at a currently-operating nuclear power plant. Ultimately, expansions resulting from ASR (and cracking due to those expansions) are the primary concern with respect to structural performance. To that end, we find that the LSTP specimens are appropriately representative.

108.

The Board finds that a preponderance of the evidence demonstrates that chemical mineralogy is not a critical parameter for representativeness, and that the use of a faster-reacting concrete mix (which purposefully does not yield a representative rate of expansion) is 245 Tr. at 1008.

246 Id.

247 Saouma, V. Experimental and Numerical Investigation of Alkali Silica Reaction in Nuclear Reactors at 6 (Dec. 2017) (INT005) (to enhance the reaction, cement with a high natural alkalinity was selected and then the alkalinity was further raised by adding sodium hydroxide).

57 common and necessary for accelerated ASR testing, and neither compromises the applicability of the LSTP data to Seabrook nor defeats a finding of reasonable assurance.

109.

As to compressive strength, NextEras evidence demonstrates that the 28-day compressive strength of the reference location (i.e., the B Electrical Tunnel) was approximately 5,500 psi.248 To promote representativeness, the LSTP established compressive strength acceptance criteria for the test specimens in the range of 3,000 to 7,000 psi, which is consistent with the industry definition for normal strength concrete.249 NextEras evidence shows that this range was chosen based on both the target compressive strength of the reference location, and also on important overarching behavioral differences in concrete above and below these particular thresholds. Below 3,000 psi, concrete is not considered structural concrete, but is more akin to sidewalk concrete.250 And above 7,000 psi, concrete would be considered high-strength concrete, which can present different (and non-representative) failure modes than normal strength concrete.251 The compressive strength acceptance range for the LSTP provides margin at either end to ensure behavior is consistent with normal strength concrete.252 110.

Dr. Saoumas criticism is that the acceptance range of 3,000 to 7,000 psi is a huge range of compressive strengths, which creates a potential source[] of error in the LSTP results.253 But Dr. Saoumas criticism that the acceptance range is too broad is inconsistent with the intended purpose of this criterion, which is discussed above and in MPR-3757. Further, as a 248 See MPR-3757, Rev. 4, Shear and Reinforcement Anchorage Test Specimen Technical Evaluation at 3-2 tbl.3-1 (May 2014) (FP100760) (MPR-3757) (NER026) (NER026).

249 MPR Testimony at A115 (NER001).

250 Tr. at 598; MPR Testimony at A115 (NER001).

251 Tr. at 597-98; MPR Testimony at A115 (NER001).

252 MPR-3757, Section 3.2.1 (NER026).

253 Tr. at 515.

58 practical matter, the evidence shows that the compressive strengths of the LSTP shear specimens were between approximately 4,100 and 4,800 psi, and Seabrooks structures are between approximately 4,200 and 6,000 psiin other words, in the middle of the acceptance range.254 Therefore, the range of actual compressive strengths was significantly narrower than the acceptance range, and none of the specimens or structures are remotely close to either extreme end of the acceptance range. Furthermore, the test results were normalized by compressive strength to account for the differences in compressive strength between the specimens.255 111.

NextEras evidence also shows that the purpose of the LSTPs shear testing was to evaluate the code expression for concrete contribution to shear strength; and that the applicability of the code expression itself, is not sensitive to differences in compressive strengths in the LSTPs acceptance range.256 Specifically, Dr. Bayrak testified that the industry-accepted code expression widely used for calculating shear strength is applicable for a range of compressive strengths even broader than the LSTPs range of 3,000 to 7,000 psi.257 Dr.

Saouma did not challenge NextEras conclusion in this regard.258 Thus, the preponderance of the evidence shows that compressive strengths within the LSTPs range do not introduce a source of error into the calculation of the shear strength using the relevant Code expression.

112.

Dr. Saouma argues that, if concrete of a specific numerical strength exists at Seabrook, and concrete of an identical numerical strength was not tested in the LSTP, then the testing is not representative in the full sense of the term.259 But we find that replication for its 254 Id. at 596-99.

255 MPR-4273 §§ 5.1.2, 5.2.2 (INT019-R (NP), (INT021)(P)).

256 Tr. at 599.

257 Id. at 599-600.

258 Id. at 600 (one can argue that it doesnt affect the shear strength. Thats open for debate.)

259 Id.

59 own sake (i.e., in the full sense of the term) is not a requirement in any accepted code, standard or regulation to demonstrate reasonable assurance.

(2)

Specimen Scale and Reinforcement Configuration 113.

As noted above, the Board has concluded that LSTP specimen scaling was not one of the aging and environmental parameters challenged in the original Contention, and thus C-10s arguments on this topic are outside the scope of this proceeding. Nevertheless, even if those arguments were within scope, a preponderance of the evidence demonstrates that NextEras approach to LSTP specimen scaling provides reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

114.

In Section C.2.2.1 of his testimony, Dr. Saouma claims that a significant problem with the FSEL testing is the failure to ensure that the relative dimensions of the concrete beam that was tested were scaled to the prototype.260 However, NextEra purposefully developed the LSTP with specimen scale in mind.261 Indeed, that was one of the primary reasons the LSTP was undertakenbecause data in existing literature was based on specimens too small to be considered representative of Seabrooks structures.262 115.

NextEra presented evidence that the appropriate scaling parameters for shear testing are thickness, shear-span-to-depth ratio (i.e., the distance between a concentrated load and the support divided by the beam depth), reinforcing bar size, reinforcing bar spacing, and 260 Saouma Testimony § C.2.2.1 (INT001-R).

261 MPR Testimony at A85 (NER001) (shear is known to scale poorly from laboratory-scale specimens to actual large structures, as discussed in Dr. Bayraks report Structural Implications of ASR; State of the Art at 10 (Feb. 2, 2012) (State of the Art) (NER019)) (also citing Chana and Korobokis, Structural Performance of Reinforced Concrete Affected by Alkali Silica Reaction: Phase 1 § 7.2 (Oct. 1990) (NER054)).

262 MPR Testimony at A200 (NER001).

60 concrete cover over reinforcing bars.263 Dr. Saouma fully agree[s] that the LSTP considered the appropriate range of scaling parameters.264 Thus, we find that a preponderance of the evidence demonstrates that the LSTP considered the appropriate range of scaling parameters.

116.

NextEra presented evidence that the physical dimensions of the LSTP specimens were similar or identical to the reference location at the planti.e., the B Electrical Tunnel at Seabrook.265 In other words, the ratio between the LSTP and the Seabrook reference location was 1:1.266 Dr. Saoumas criticism, however, is that the 1:1 scaling ratio is based only on a single location at the plant and therefore is inapplicable to other locations.267 But NextEras evidence demonstrates that the other walls and structures of interest at Seabrook are of similar size and scale. NextEra also explained that precise replication of all structures throughout the plant was not only impractical, but unnecessary and inconsistent with the technical basis for the Seabrook design codes, ACI 318 and the ASME Code.268 117.

Importantly, NextEras detailed consideration of specimen size and scaling is presented in MPR-3757 (NER026). But the record contains no evidence that Dr. Saouma reviewed this document or disputed its content.269 In contrast, the record does include evidence supporting NextEras claim that any variance in scaling between the Seabrook reference location 263 MPR Testimony at A200 (NER001). See also Tr. at 428 (Dr. Bayrak explaining that thickness is the parameter of interest, and the other two dimensions are not germane).

264 Tr. at 613. See also id (Dr. Saouma acknowledging length of a specimen is immaterial to shear testing).

265 MPR Testimony at A200 (NER001).

266 MPR Testimony at A103, A110, A115, A200 (NER001). The parameters of interest come from the testing that informed the original code equations, which have been in use in structural engineering for many decades. Tr.

at 428.

267 Tr. at 613.

268 MPR Testimony at A107, A200 (NER001).

269 Dr. Saouma did not include MPR-3757 in the list of materials that he reviewed in preparation for his testimony. See Saouma Testimony § A.5 (INT001-R).

61 and other locations at Seabrook is de minimis and was explicitly contemplated and accounted for in the development of the LSTP. More specifically, the record shows that the use of large-scale specimens means that the scaling factor between the test specimens and other areas of the plant is close to 1:1 for any location.270 Furthermore, the purpose of the LSTP was to evaluate the impact of ASR on shear strength (if any) such that the code expression could be applied uniformly to Seabrook structures regardless of thickness.271 On balance, we find that C-10 presented insufficient evidence to support its claim that the representativeness of the LSTP is challenged by the lack of testing of specimens with thicknesses other than that of the reference location, and that a preponderance of the evidence demonstrates that C-10s criticism regarding specimen dimensions does not defeat a finding of reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

118.

Dr. Saouma also claimed that the LSTP was not representative because the test specimens had different reinforcement ratios and were not scaled consistent with the structures at the plant.272 But the preponderance of the evidence demonstrates that, with one exception addressed in the paragraph below, no scaling of the test specimen reinforcement configuration was required because the reinforcing bar size, reinforcing bar spacing, and concrete cover over reinforcing bars were similar or identical to the reference location at the plant.273 In other words, the reinforcement ratio scale between the LSTP and Seabrook is 1.0.274 270 MPR Testimony at A200 (NER001); see also MPR-3757 (NER026).

271 Tr. at 428, 612-13.

272 Saouma Testimony § C.2.2.1 (INT001-R); see also Saouma Rebuttal § D.3.1 (INT028).

273 MPR Testimony at A200 (NER001).

274 Id.

62 119.

There was one exception to the LSTPs replication of Seabrooks reinforcement spacing. More specifically, as is done in essentially all shear testing, the LSTP shear specimens used additional rebar (i.e., a higher ratio than at Seabrook) in the longitudinal direction because a fundamental basis for the Codes used to design the Seabrook structures is to cause other modes (e.g. flexure) to control over shear; thus, the reinforcement within the test specimens had to be altered to allow shear to control the performance of the specimens.275 This was a purposeful decision in the testing approach, designed to ensure that the specimens would fail in the mode of interest (i.e., shear) rather than some other mode (e.g., flexure).276 Dr. Saoumas criticism appears to be that this approach unnecessarily renders the test specimen less representative of the reference location.277 But Dr. Saouma, too, was concerned regarding the possibility of an erroneous failure mechanism, which he acknowledged would make the failure load non-representative.278 However, that is why NextEra evaluated this potential phenomenon in the planning phase of the testing programs.279 NextEra concluded that use of additional longitudinal reinforcing bars in the shear test specimens provided additional flexural capacity, and therefore ensured that failure during load testing would be in shear rather than flexure.280 And at the conclusion of the testing, NextEra confirmed these design efforts were, in fact, successful by confirming that the test specimens failed by the appropriate mode.281 275 Id.

276 Id.

277 Saouma Rebuttal § D.3.1 (INT028); id. (quoting MPR-3848 noting that, under this approach, using the in plane CCI to translate between test results and structures at Seabrook Station will be conservative).

278 Saouma Testimony § C.2.2.1 (INT001-R).

279 MPR Testimony at A200 (NER001); MPR-3757 §§ 2, 3 (NER026).

280 See MPR-3757 § 3.2.3 (NER026).

281 See, e.g., MPR-4262 at 6-10 to 6-11, figs.6-9 & 6-10 (NER022-R).

63 120.

Dr. Saouma acknowledges that specimens need only be scaled properly as much as possible.282 C-10 presented no evidence to show that it was possible (or necessary, for purposes of representativeness) to perform shear testing using some other reinforcement configuration that would preclude erroneous failure mechanismwhich C-10 agreed was an important consideration.283 NextEras rationale in selecting reinforcement for the LSTP specimens is presented in MPR-3757 (NER026), and its confirmatory review is documented in MPR-4262 (NER025-R). Again, the record contains no evidence that Dr. Saouma reviewed these documents or disputed their contents.284 On balance, we find that C-10 presented insufficient evidence to support its claim that the representativeness of the LSTP is challenged by NextEras use of additional rebar in the longitudinal direction in the LSTP shear specimens.

Thus, a preponderance of the evidence demonstrates that C-10s criticism regarding reinforcement ratio does not defeat a finding of reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

(3)

Experimental Design 121.

As noted above, the Board has concluded that C-10s various criticisms of the execution of the LSTP were not among the aging and environmental parameters challenged in the original Contention, and thus C-10s arguments on this topic are outside the scope of this proceeding. Nevertheless, even if those arguments were within scope, a preponderance of the evidence demonstrates that none of C-10s criticisms regarding the execution of the LSTP defeat a finding of reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

282 Tr. at 275.

283 Saouma Testimony § C.2.2.1 (INT001-R).

284 Dr. Saouma did not include MPR-3757 (the Shear Test technical evaluation) or MPR-4262 (the Shear Test results) in the list of materials that he reviewed in preparation for his testimony. See Saouma Testimony § A.5 (INT001-R).

64 122.

NextEra testified that, consistent with long-standing industry-standard tests for studying shear behavior, as documented in MPR-3848 (NER015), the LSTP test setups were not aimed at replicating in situ boundary conditions at Seabrook (i.e., external influences on the structural elements such as interactions with adjacent structural components).285 NextEra concluded that it was essential that the specimens from the LSTP represent what was previously tested by many research groups around the world to obtain data to serve as the basis for the shear design expressions in the codes.286 The relevant code expressions are designed for applicability to a variety of structural elements (e.g., walls, slabs, beams, columns), consider inherent variations in boundary conditions, and are based on the most severe boundary conditions to obtain the most conservative results.287 NextEra further concluded that replicating boundary conditions for every specific location at Seabrook impacted or potentially impacted by ASR would be impractical, excessively complex, and ultimately would not meaningfully inform a comprehensive engineering evaluation of the mechanisms of interest.288 Thus, consistent with the codes, the LSTP used the most severe loading and boundary conditions for the limit states of interest, which ultimately produced failure in the target region by the desired failure mode.289 Dr. Bayrak testified that this approach allowed the LSTP to yield conservative resultsin many examples, greatly so.290 123.

C-10 argues that axial forces from in situ boundary conditions can negate the pre-stressing effect observed in ASR-affected reinforced concretemore specifically, that the 285 MPR Testimony at A107 (NER001); MPR-3848 § 4.3 (NER015).

286 Id. at A106.

287 Id. at A62, A108.

288 Id. at A108.

289 Id.

290 Tr. at 283; see also MPR Testimony at A203 (NER001).

65 pre-stressing effect may be dwarfed by axial loads from gravity, and therefore cannot be relied upon.291 Thus, according to C-10, NextEras failure to replicate these axial load conditions caused the LSTP data to be unrepresentative of Seabrook.292 But this claim overlooks the fact that the LSTP was designed as a separate effects test, so the structural loading mode naturally focused on the limit state in question.293 As relevant here, independent effects of the other axial loads described by Dr. Saouma are, in fact, addressed on a structure-specific basis through NextEras Structural Evaluations.294 Thus, it would have been inappropriate to include axial compression forces in both the LSTP and the Structural Evaluations.295 C-10 did not rebut this assertion. NextEras experts also testified that restraint provided by the in situ boundary conditions would in fact benefit shear strengththus, the LSTP approach is more representative.296 C-10 also did not rebut this assertion either.

124.

On balance, we find that C-10 presented insufficient evidence to support its assertion that the representativeness of the LSTP is challenged by the lack of replicating Seabrooks in situ boundary load conditions, and that NextEra presented sufficient evidence to provide a technical justification for its separate-effects testing approach.

125.

C-10 also criticizes the LSTP for modeling only the out of plane shear and not the in-plane.297 NextEra explained that, in the context of Seabrook, out-of-plane shear is not 291 Saouma Testimony § C.2.2.2 (INT001-R).

292 Id.

293 MPR Testimony at A203 (NER001).

294 MPR-4288 (INT012 (NP), INT014 (P)); SEM Document (INT022).

295 MPR Testimony at A203 (NER001).

296 Id.

297 Saouma Testimony § C.2.2.2 (INT001-R).

66 resisted by reinforcement, whereas in-plane shear is.298 As discussed in MPR-3727, NextEra reviewed published literature and confirmed that the one-way shear strength of test specimens with a minimum quantity of transverse reinforcement was not affected by ASR. Accordingly, the in-plane shear strength of walls (reinforced with more than a minimum quantity of reinforcement) was not a concern for Seabrook due to the beneficial effects of chemical prestressing or confinement provided by reinforcing bars.299 Thus, based on this existing body of published research, NextEra concluded there was no need to evaluate in-plane shear as part of the LSTP.300 126.

C-10 presented no evidence to contradict the published literature on this point.301 Dr. Saouma merely commented that in-plane shear presents a potential for debonding of the rebar between the wall and the base.302 However, Dr. Saouma stated that he did not know whether this was accounted for in the LSTP.303 Whereas, Dr. Bayrak noted that this was explicitly addressed in our reinforcing bar anchorage testing programs.304 As noted above, the reinforcement anchorage test program was neither reviewed nor challenged by Dr. Saouma, who 298 MPR Testimony at A202 (NER001).

299 Id. See also MPR-3727, Rev. 1, Seabrook Station: Impact of Alkali-Silica Reaction on Concrete Structures and Attachments (Jan. 2014) and NextEra Supplements I-V Thereto (FP100716, Rev. 4) tbl.6-4 (MPR-3727) (NER018). See also State of the Art, tbl.4 (NER019); D. Deschenes, et al., ASR/DEF-Damaged Bent Caps: Shear Tests and Field Implications, Technical Report No. 12-8XXIA006 summarizing work conducted for the Texas Dept of Trans. at Ferguson Structural Engg Lab., The Univ. of Texas at Austin § 7.2.2 (Aug.

2009) (NRC075).

300 MPR Testimony at A202 (NER001); MPR-3727 (NER018).

301 Dr. Saouma did not include MPR-3727 in the list of materials that he reviewed in preparation of his testimony.

See Saouma Testimony § A.5 (INT001-R).

302 Tr. at 914.

303 Id.

304 Id. at 915.

67 confirmed his lack of expertise on this topic at the evidentiary hearing.305 On balance, we find that NextEras evidence supports its assertion that the representativeness of the LSTP is not challenged by the lack of in-plane shear testing.

127.

In his initial written testimony, Dr. Saouma alleged that NextEra had failed to address load-displacement and cracking pattern in the LSTP, and raised several criticisms on those topics.306 In its responsive testimony, NextEra explained that those items had in fact been addressed in the LSTP and rebutted each of Dr. Saoumas criticisms.307 For example, Dr.

Saouma questioned whether the load testing of shear specimens actually produced a shear failure, and criticized the LSTP reports for lack of pictures showing the shear cracks.308 NextEras experts testified, with citation to record evidence, that these claims were directly refuted by extensive documentation (including photographs) from the LSTP.309 At the evidentiary hearing, Dr. Saouma withdrew those arguments and noted that he had simply missed the relevant information.310 Thus, we find that NextEras evidence that the LSTPs treatment of load-displacement and cracking supports a finding of reasonable assurance that the LSTP yielded data appropriate for use in the LAR.

E.

The SMP 128.

As explained in LBP-17-7, the sole basis in the admitted Contention for C-10s challenge to the LARs monitoring, acceptance criteria, and inspection intervals was the alleged 305 See Saouma Testimony § A.5 (MPR-3722 (anchorage test report) not listed among documents reviewed); Tr.

at 266 (Dr. Saouma: I dont claim expertise on anchorage).

306 Saouma Testimony § C.2.3 (INT001-R).

307 MPR Testimony at A204-208 (NER001).

308 Saouma Testimony § 2.3.1 (INT001-R).

309 MPR Testimony at A204 (NER001) (citing, e.g., MPR-4259, app. G at G-14, G18-G19 (NER025-R).

310 Tr. at 314.

68 non-representativeness of the LSTP. As noted above, the Board has concluded that a preponderance of the evidence shows the LSTP data are, in fact, representative and appropriate for use in the LAR. As a result, the Contention must be resolved in NextEras favor, and the Board need not consider C-10s further arguments regarding the LARs monitoring, acceptance criteria, and inspection intervals.

129.

Nevertheless, as explained below, the Board has evaluated the SMPs monitoring, acceptance criteria, and inspection intervals, and concludes that a preponderance of the evidence demonstrates that NextEras SMP is adequate to support a finding that reasonable assurance exists for the NRC Staff to grant the LAR. Furthermore, as explained below, we find that C-10s criticisms of the SMP do not defeat a finding of reasonable assurance.

130.

Seabrooks SMP (which is a typical program at nuclear power plants used to address the aging of structural elements within the scope of the maintenance rule, 10 C.F.R.

§ 50.65) includes specific provisions for ongoing ASR monitoringi.e., the ASR Monitoring Program. Under this aspect of the SMP, NextEra performs an overall assessment and screening of concrete throughout the plant. In particular, NextEra uses crack width indexing as part of its SMP to evaluate ASR throughout the plant, consistent with published literature (e.g., FHWA Guideline, ISE Guideline), to determine in-plane expansion, which is used as a screening tool to determine whether an extensometer should be installed at that location. For areas with in-plane expansion above 0.05%, NextEra also uses pin-to-pin measurements to corroborate crack width index measurements.311 To date, they continue to track together.312 As a general matter, the LSTP confirmed that crack width indexing does, in fact, represent the overall in-plane expansion 311 MPR Testimony at A127, A163 (NER001); see also SMPM ch. 3 § 1.3.1 (NER007).

312 Tr. at 501.

69 of a concrete surface.313 And the LSTP compared crack width indexing measurements (obtained using a documented procedure under a nuclear QA program) against mechanical gauge expansion measurements and found that the two are consistent in trend and magnitude.314 131.

If in-plane expansion exceeds 0.1% (1 mm/m), NextEra installs an extensometer to commence through-thickness expansion monitoring. As NextEra demonstrated, this threshold is approximately the point of divergence of the ASR strains in all three directions, regardless of the presence of reinforcement.315 NextEra then monitors in-plane, through-thickness, and volumetric expansion (i.e., the total of the measured expansion in each of the three directions) to ensure that these parameters remain below the levels achieved at the LSTP (i.e., that they meet the corresponding acceptance criteria in the SMP, aka the Expansion Monitoring Limits). We find that these monitoring methods are entirely reasonable and appropriate for application at Seabrook in order to ensure seismic Category I structures comply with the plants licensing basis and can continue to perform their intended safety functions.316 132.

NextEras testimony describes the acceptance criteria for determining when an extensometer is needed, and for each of the monitoring parameters (i.e., in-plane, through-thickness, and volumetric),317 and describes the SMPs graded monitoring approach, which includes monitoring on an interval that reflects the observed condition of Seabrook structures.318 313 Tr. at 320.

314 Tr. at 323, 471-72. The LSTP did identify a small lag between the two at the early stages of the comparison, representing the period before cracks form and become large enough to be observed and included in the crack width index data set. MPR Testimony at A166; Tr. 471. But the two agree closely starting at relatively low levels of expansion. Prop. Appx, fig.4 (NER003).

315 MPR Testimony at A180 (NER001); see MPR-4273 § 6.1.1 (INT019-R (NP), (INT021)(P)).

316 MPR Testimony at A163-A167 (in-plane expansion); A168-A176 (through-thickness expansion); A177-A178 (volumetric expansion) (NER001).

317 Id. at A179, A181, A183, A185.

318 Id. at A187.

70 NextEras evidence provides a technical justification for each acceptance criterion,319 and for the monitoring frequencies.320 133.

Further, the approved amendment includes a license condition requiring NextEra to perform periodic expansion assessments, which includes evaluation of the rate of ASR progression (Periodic Expansion Assessment). If data suggest that the monitoring intervals (or any other aspect of the SMP) at Seabrook are insufficient, the plant will evaluate the need for potential changes.321 134.

We conclude that the preponderance of the evidence demonstrates that the monitoring techniques, acceptance criteria, and inspection intervals in NextEras SMP are adequate to provide reasonable assurance.

(1)

SMP ASR Expansion Monitoring Techniques 135.

As the Commission explained, In Contention A, as admitted, C-10 challenges the effectiveness of crack width indexing and extensometer deployment as tools for determining the presence and extent of ASR in safety-related structures. C-10s concerns regarding these monitoring techniques arise from the question of whether the test program results can adequately predict the effectiveness of crack width indexing and extensometer deployment as monitoring techniques at Seabrook.322 319 Id. at A180, A182, A184, A186.

320 Id. at A188-A193.

321 Id. at A193.

322 Seabrook, CLI-18-4, 87 NRC at 94.

71

a.

In-Plane Expansion 136.

As a preliminary matter, we note that the crack width indexing technique was not developed by NextEra.323 It is a well-established technique, endorsed by various respected industry guidelines.324 Dr. Saouma acknowledges that crack width indexing is an appropriate first step in monitoring ASR.325 But he argues that, once ASR becomes more serious, monitoring programs must go beyond that.326 But the evidence demonstrates that NextEras SMP does precisely that. Once in-plane expansion exceeds 0.05%, NextEras SMP goes beyond crack width indexing to also include performing pin-to-pin measurements for in-plane expansion. And beyond that, once in-plane expansion exceeds 0.1%, NextEra then installs extensometers, examines and tests material properties of cores, and performs structural evaluations (if not already performed). As detailed below, we find that C-10 presented no evidence to suggest that 0.1% is the incorrect threshold to commence through-thickness and volumetric monitoring, and no evidence to challenge NextEras use of crack width indexing beyond 0.05% in conjunction with other monitoring techniques.

137.

First, Dr. Saouma claims that crack width indexing can only be used in conjunction with advanced petrography.327 As support for his assertion, Dr. Saouma points to the FHWA Guideline, which recommends a combination of crack width indexing and petrography for the preliminary investigation stage of an ASR assessment program.328 NextEra 323 MPR Testimony at A217 (NER001); see also Tr. at 323 (Dr. Bayrak stating that he and NextEra did not develop and cannot take credit for crack width indexing).

324 See, e.g., FHWA Guideline (NER013); ISE Guideline (NER012); see also Tr. at 323-24.

325 Tr. at 494-95.

326 Tr. at 495.

327 Saouma Testimony § C.3.1.2. (INT001-R).

328 Id. (citing FHWA Guideline § 2.2 (NER013)).

72 did perform crack width indexing and petrography during its preliminary investigation.329 But the FHWA Guideline also explicitly endorses crack width indexing during the later detailed study stage of an ASR assessment program to generate a quantitative assessment of the extent (severity) of deterioration.330 The record otherwise contains no evidence indicating that crack width indexing is an invalid monitoring technique absent companion petrography.331 Thus, C-10s assertion in this regard does not defeat a finding of reasonable assurance.

138.

C-10 also argues that crack width indexing is not an appropriate monitoring technique because the surface of Seabrooks concrete has dried. C-10 asserts that ASR cannot propagate if the relative humidity is less than 80%. Thus, according to C-10, surface ASR will not cause Seabrooks surface concrete to expand or crack. Meanwhile, per Dr. Saoumas theory, internal expansion and cracking could go undetected, and hidden internal delamination could occur.332 Thus, Dr. Saouma claims, NextEra also must monitor relative humidity at the surface of the concrete and deeper within the concrete in order to predict whether ASR may occur.

139.

NextEras evidence, however, demonstrates that surface cracking will indicate the potential presence of internal expansion due to ASR even if ASR is not present (or is not propagating) at the concrete surface.333 In other words, NextEras experts testified that there simultaneously could be internal ASR expansion along with zero ASR at the surface, and the 329 SGH Testimony at A65 (NER004) (citing SG&H Report 110594-RPT-02, Rev. 1, Damage Rating Index and ASR Rating (Feb. 10, 2012) (FP100702) (SG&H Report) (NER028)).

330 FHWA Guideline §§ 5.2.1 & 5.2.2. (NER013).

331 Moreover, to the extent C-10 asserts that ASR gel chemistry or crack pattern somehow impact the efficacy of crack width indexing, Dr. Saouma acknowledges any such connection is attenuated. Tr. at 425-26.

332 Dr. Saouma also claimed that an LSTP specimen experienced delamination. However, we find that NextEra sufficiently demonstrated that it was an edge effect crack, not an internal delamination. See MPR Testimony at A208 (NER001); MPR-4273, § 4.2.3 (INT019-R (NP), (INT021)(P)); MPR-4262 § 5.2.3 (NER022).

Accord Tr. at 1138 (NRC Staff stating they were present and observed first-hand that it was an edge effect crack).

333 See, e.g., SGH Testimony at A65 (NER004).

73 internal ASR expansion still would manifest itself through surface cracking. As NextEras experts further explained, this is because surface cracking can be caused by many things in addition to ASR, including shrinkage (which would occur if the surface concrete has dried),

and differential movement wherein the expansion of the interior concrete would create forces and movements that would crack the relatively thin zone of drier near-surface concrete as it was forced to move along with the expanding interior concrete (e.g., where the inside is expanding but the surface is not).334 [Placeholder for discussion of INT049-R and INT050, if admitted by the Board, and any responsive testimony and exhibits permitted by the Board.335]

140.

NextEras technical justification is supported by the FHWA Guideline (NER013),

which states:

cracking at the surface of a concrete member reflects differential deformations (expansion or contraction) between the surface and the inner concrete due to various mechanisms such as ASR, sulphate attack, freezing/thawing, and shrinkage.336 Conservatively, NextEras SMP initially presumes that all cracking is caused by ASR.337 141.

C-10 provides no evidentiary support, other than Dr. Saoumas opinion, for its assertion that internal ASR cracking so severe that it causes delamination somehow could occur without any indication on the surface.

334 See, e.g., Tr. at 497 (Mr. Sherman analogizing surface concrete without ASR expansion to a dry lake bed, and noting that cracking will still occur due to surface shrinkage or subsurface expansion/deformation that drags all those top pieces along); id. at 499 (Mr. Sherman explaining that, [v]ery specifically, since th[e] surface is not expanding [due to ASR], [crack indexing is] actually catching more of the inner expansion thats happening).

335 [As of the due date for submission of the FOF/COL, the Board had neither ruled on C-10s pending motions to submit additional testimony and exhibits nor closed the evidentiary record.]

336 FHWA Guideline at 30 (NER013) (emphasis added).

337 MPR Testimony at A214 (NER001).

74 142.

Dr. Saoumas written testimony included photographs of unknown structures (described as surface reinforced concrete retaining walls) with visible cracks (which Dr.

Saouma characterized as delamination).338 However, the cause of the readily visible cracking shown in the photographs is unknown because they were not accompanied by a source document with further technical details and factual observations. At the evidentiary hearing, Dr. Saouma stated that these photographs came from a German-language document, but C-10 subsequently indicated that it would not file the German document as an exhibit. Instead C-10 stated it would rely on an existing exhibitthe ISE Guideline (NER012)which it viewed as sufficient on this point.339 More specifically, Dr. Saouma pointed to the ISE Guideline for its discussion of microcracks.340 However, we see no support in that discussion of microcracks for Dr.

Saoumas assertion that large hidden delamination, without any other signs of cracking or structural deformation, is plausible.341 Further, the photographs, whatever their source, show readily visible surface cracking, not hidden delamination, and do not show any condition (cracked or not) of the perpendicular face on which the purported delamination would or would not be visible.

143.

NextEra provided further evidence demonstrating that the SMP requires a core to be removed and an extensometer installed if in-plane expansion exceeds 0.1%, and that all of those cores (and the corresponding boreholes) be visually inspected.342 To date, in over 200 338 Saouma Rebuttal at 33 fig.16 (INT028).

339 Tr. at 959-60.

340 Tr. at 889-91.

341 See also Tr. at 891-92 (Mr. Lehman observing that the ISE Guideline itself makes clear that microcracking is not delamination); id. at 892 (Dr. Saouma agreeing that microcracks would become macrocracks prior to delamination).

342 MPR Testimony at A133 (NER001); Tr. at 680.

75 cores that have been evaluated, NextEra has never observed internal delamination or mid-plane cracking.343 Thus, Dr. Saoumas speculation regarding the current state of Seabrooks concrete is contradicted by direct physical evidence from Seabrook. Moreover, Dr. Saoumas concern that possible future internal cracking or internal delamination could go undetected is refuted by NextEras SMP, which provides a specific and mandatory requirement to inspect cores for such internal cracking or delamination on a going-forward basis,344 and Seabrooks license, which contains a condition requiring NextEra to review cores for mid-plane cracking as part of the Periodic Expansion Assessments.345 144.

To the extent Dr. Saouma speculates that internal cracking or delamination (severe enough to compromise the structures ability to perform its intended safety function) could occur in the future before a core is removed and inspected (i.e., where in-plane expansion is less than 0.1%), he provides no evidence to support his assertion.

145.

We conclude that the preponderance of the evidence demonstrates that the SMPs acceptance criteria limit for in-plane expansion, the use of crack width indexing to monitor in-plane expansion up to 0.1%, and the use of crack width indexing plus pin-to-pin measurements to monitor in-plane expansion from 0.05% to the acceptance criteria limit are adequate to provide reasonable assurance.

b.

Through-Thickness Expansion 146.

NextEras SMP measures through-thickness expansion against established acceptance criteria. However, because Seabrook was not originally constructed with embedded 343 MPR Testimony at A208 (NER001); MPR-0326-062-88 Rev. 2 at 4 (NER020); Tr. at 456, 572, 705, 1097.

344 SMPM, ch. 3 at 3-1.5 (NER007) (The cores that are taken will be subjected to visual examination to confirm the absence of mid-plane cracks).

345 MPR Testimony at A94 (NER001).

76 instruments to measure through-thickness expansion due to ASR, NextEra uses a two-part process to calculate through-thickness expansion.346 Previous (i.e., historical) through-thickness expansion is calculated via an empirical correlation using elastic modulus.347 And additional (i.e., going forward) expansion is measured with an extensometer. Combining the two values provides the total through-thickness expansion, which is measured against acceptance criteria in the SMP.

147.

C-10 does not offer any specific challenge to or criticism of the use of extensometers to measure through-thickness expansion going forward. Dr. Saoumas initial testimony commented that extensometers should be placed at least at mid-distance between the

[two sides of a wall].348 But Seabrooks procedures specify that the deep anchor for each extensometer be installed well beyond the midpoint of the wall thickness.349 Thus, Dr. Saoumas remark is entirely consistent withand identifies no deficiency inthe SMP. At the evidentiary hearing, Dr. Saouma noted that he no longer has any concerns regarding NextEras use of extensometers in the SMP.350 NextEras evidence also shows that the LSTP examined various instruments for measuring through-thickness expansion and determined that the snap-ring borehole extensometer was the best instrument.351 C-10 did not challenge these conclusions. 352 Thus, we conclude that the preponderance of the evidence demonstrates that NextEras use of 346 MPR Testimony at A168 (NER001).

347 Id.

348 Saouma Testimony § C.3.2. (INT001-R) (emphasis added).

349 MPR Testimony at A213 (NER001) (citing Seabrook Mechanical Maintenance Procedure MS0517.51, Installation of Geokon Snap-Ring Borehole Extensometers Rev. 0, figs.1-7 (Feb. 2016) (NER046)).

350 Tr. at 458 (I have corrected myself... so Im perfectly fine with it).

351 MPR Testimony at A156-57 (NER001); MPR-4273 §§ 5.4.2 & 5.4.3 (INT019-R (NP), (INT021)(P)).

352 See supra note 222 (C-10s expert was unaware of the instrument testing program).

77 extensometers as a monitoring technique for ongoing through-thickness expansion is adequate to provide reasonable assurance.

148.

However, in rebuttal, Dr. Saouma raisedfor the first time in the proceedingan argument regarding NextEras method for estimating previous through-thickness expansion (aka the Modulus Correlation described in the next paragraph).353 As noted above, the Board has concluded that C-10s new rebuttal arguments (including this one) are impermissible and thus are stricken from the record. Thus, all of the evidence in this proceeding supports the adequacy of NextEras Modulus Correlation. Nevertheless, even if those arguments were permissible, a preponderance of the evidence demonstrates that none of C-10s criticisms defeats a finding of reasonable assurance.

149.

C-10 does, however, challenge NextEras Modulus Correlation (i.e., its technique for estimating previous through-thickness expansion which involves:

Determining the current elastic modulus of the concrete by material property testing of cores removed from the structure.

Calculating the reduction in elastic modulus by taking the ratio of the test result from the ASR-affected area to the original elastic modulus (i.e., the normalized elastic modulus).

Quantifying through-thickness expansion using a correlation developed as part of the LSTP, which relates reduction in elastic modulus with measured expansion from beam specimens used during the LSTP.354 150.

Dr. Saouma stated at the evidentiary hearing that this technique is an approximation, and has a margin of error that he claims has not been accounted for.355 However, NextEra explicitly addressed uncertainty in this technique in MPR-4153. Indeed, that 353 Saouma Rebuttal § D.9.1 (NER028).

354 MPR Testimony at A171 (NER001). See also MPR-4153 at iv (INT018-R (NP), INT020 (P)).

355 Tr. at 515.

78 document contains an entire section devoted to Uncertainty Considerations, which analyzes and evaluates the potential sources of uncertainty and their related impacts.356 151.

The evidence shows that NextEra took various affirmative steps to address potential uncertainty in the Modulus Correlation. First, the current elastic modulus for an entire concrete member will be determined based on the area with the greatest symptoms of ASR-related expansion, thus conservatively characterizing the elastic modulus of the member.357 Second, NextEra applies a reduction factor to the normalized elastic modulus to add conservatism to the calculated through-thickness values (the reduction factor artificially increases the estimated through-thickness expansion and reduces the margin to the acceptance criteria), thereby addressing potential uncertainty associated with the original modulus.358 Third, NextEra validated the Modulus Correlation against published literature data, and presented the assessment in MPR-4153.359 C-10 challenged none of the published literature or NextEras assessment. Finally, NextEra will conduct a Corroboration Study in 2025, and again ten years later, to obtain in-plant data to corroborate the approach for using the Modulus Correlation.360 In essence, NextEra will take new cores adjacent to a sampling of the 20% of existing extensometer locations to calculate expansion using the Modulus Correlation technique, and then compare the results to the actual measurements obtained from the extensometers.361 This is an explicit legally-enforceable condition of NextEras operating license.362 356 MPR-4153 § 4.2 (INT018-R (NP), INT020 (P)).

357 Id.

358 Id.

359 MPR Testimony at A175 (NER001); MPR-4153 (INT018-R (NP), INT020(P)).

360 MPR Testimony at A95 (NER001).

361 Id.

362 Id. at A93, A96 (NER001).

79 152.

C-10 did not challenge NextEras approach of selecting the worst case location for determining the elastic modulus. However, it did challenge the value of the reduction factor, because, in its view, there is a lot of uncertainty in the Modulus Correlation.363 NextEras evidence demonstrates that the value of the reduction factor was confirmed based on an analysis of the normalized elastic modulus and through-thickness expansion of 21 sets of cores removed from LSTP specimens where that reduction factor yielded a result that bounded or closely approximated 20 of the 21 sets of cores.364 Dr. Bayrak testified that this was akin to a 5 percent fractal approach that leaves 95% of the data on the safe side, and that this is a commonly-used technique (in lieu of error bars) among structural engineering practitioners in the ACI and the International Concrete Federation.365 C-10 did not offer an alternative reduction factor, and acknowledged that the value used by NextEra may, in fact, be appropriate.366 C-10 also did not dispute Dr. Bayraks testimony regarding the industry standard 5 percent fractal approach.

153.

Even if there is some uncertainty regarding the reduction factor, NextEra will conduct a Corroboration Study in 2025 to compare expansion estimated using the Modulus Correlation against actual expansion measurements at the plant. This process was added to the LAR methodology to assess any potential unconservativeness in the Modulus Correlation.

363 Tr. at 535. See also Saouma Rebuttal § D.9.1 (INT028) (listing areas of alleged uncertainty and claiming the Modulus Correlation is sensitive); Rebuttal Testimony of Victor E. Saouma, Ph.D Regarding Scientific Evaluation of NextEra's Aging Management Program for Alkali-Silica Reaction at the Seabrook Nuclear Power Plant (Revised) (Saouma Supplemental Rebuttal) (INT030-R) (claiming the Modulus Correlation fails to account for the increase in compressive strength of concrete over time due to cement hydration). But see NextEra Response to Supplemental Rebuttal (NER076) (explaining that the Modulus Correlation does, in fact, account for this curing effect, and that its sensitivity at higher expansion levels is immaterial to the overall methodology). Notably, at the evidentiary hearing, Dr. Saouma did not rebut NextEras evidence in this regard.

364 Tr. at 545; MPR-4153 fig.4-1 (INT020).

365 Tr. at 780-81.

366 Tr. at 535 (Dr. Saouma suggesting he does not know if the value is correct, or if it should be higher or lower).

80 Successful corroboration would show comparable results between the two methods.367 In other words, the results will reveal whether uncertainty adversely impacts the Modulus Correlation. If the results are not comparable, NextEra must take action to establish the pre-instrumentation expansion, reassess total through-thickness (and volumetric) expansion against the acceptance criteria established from the LSTP, and determine whether the structures [a]re operable and whether their licensing basis need[s] to be changed to address it.368 154.

However, we also must consider the period of time between now and 2025, when the Corroboration Study is completed. In this regard, the record provides the following data points: (1) the highest observed through-thickness expansion in any seismic Category I structure at Seabrook is 0.56%; (2) the current through-thickness expansion rate is 0.02% per year;369 and (3) the expansion rate has been steady since monitoring began.370 Based on these three triangulation points, one can reasonably expect the expansion at the location of highest observed through-thickness expansion to be 0.68% in 2025. In other words, it still would have decades of margin before reaching the proprietary through-thickness Expansion Monitoring Limit.

Likewise, this area (like all Tier 3 locations) will continue to be monitored on a six-month interval (which provides reasonable assurance, as discussed below in Section IV.E.(3). And should NextEras trending of expansion measurements indicate a significant rate change, it would be required to act accordingly, again, as discussed in Section IV.E.(3).

155.

Based on a preponderance of the evidence, the Board finds that the Modulus Correlation approach includes sufficient conservatism to provide reasonable assurancefor the 367 MPR Testimony at A176 (NER001).

368 Tr. at 742 (Ms. Buford speaking).

369 Tr. at 1136.

370 Tr. at 399.

81 short period of time between now and 2025that previous through-thickness expansion can be sufficiently estimated for purposes of the SMP. The Board further finds that the license condition requiring a Corroboration Study in 2025, and again in 2035, provides reasonable assurance that the Modulus Correlation approach either will be corroborated, or appropriate action will be taken by NextEra (subject to regulatory oversight) for the periods of time after 2025 and 2035, respectively.

156.

We conclude that the preponderance of the evidence demonstrates that the monitoring techniques and acceptance criteria for through-thickness expansion are adequate to provide reasonable assurance.

c.

Volumetric Expansion 157.

The evidence explains that the SMP calculates volumetric expansion by adding the measured expansion in all three directions. The purpose of evaluating volumetric expansion is that it provides an overall characterization of expansion, regardless of any preference in expansion direction.371 This value is then compared to the proprietary volumetric expansion acceptance criterion in the SMP. C-10 does not challenge NextEras technique for evaluating or calculating volumetric expansion. Thus, the preponderance ofand indeed the onlyevidence regarding the technique for volumetric expansion demonstrates that they are adequate to provide reasonable assurance.

d.

Other Monitoring Techniques 158.

As noted above, the Board has concluded that C-10s arguments that advocate alternative means of regulatory compliance are outside the scope of this proceeding.

Nevertheless, even if those arguments were within scope, a preponderance of the evidence 371 MPR Testimony at A177-78 (NER001); see also MPR-4273, app. B, § 4.3 (INT019-R (NP), INT021 (P)).

82 demonstrates that none of the alternative monitoring methods advocated by C-10 are essential to a finding of reasonable assurance.

159.

C-10 argues that NextEra should monitor the free chloride concentration in Seabrooks concrete.372 However, NextEra notes that chloride is not an alkali metal and does not participate in the ASR chemical reaction, and thus it need not be addressed as part of the ASR monitoring provisions in the SMP.373 Although chloride can cause corrosion of rebar, that degradation mechanism is covered by a separate part of the SMP,374 which is the reason the Board rejected similar arguments in C-10s original Petition as outside the scope of this proceeding. Regardless, a preponderance of the evidence demonstrates that C-10s arguments regarding chloride and rebar monitoring do not defeat a finding of reasonable assurance.

160.

C-10 advocates that NextEra should monitor the temperature and humidity for ASR affected locations at Seabrook.375 According to C-10, such information could be useful in interpreting ASR data, understanding whether ASR is likely to occur in a given location, or predicting potential future expansion.376 However, the SMPconsistent with other NRC-approved aging management programsis a monitoring mechanism, not a prediction model.

And NextEra conservatively assumes that ASR exists in all plant structures and that all cracks are from ASR, so the Board sees no practical use for such information in the context of NextEras SMP. Ultimately, a preponderance of the evidence demonstrates that C-10s 372 Saouma Testimony § C.3.2 (NER001).

373 MPR Testimony at A215 (NER001).

374 SMPM, ch. 6 § 1.3 (NER007).

375 Saouma Testimony § C.3.2 (NER001).

376 Saouma Rebuttal § A.11 (INT028).

83 arguments regarding temperature and humidity monitoring do not defeat a finding of reasonable assurance.

161.

Contentions B and C argued that the LAR should have included additional core sampling.377 More specifically, in Contention B, the Board found admissible a narrow part of the contention asserting that [t]he LAR misconstrues expansion occurring within a reinforced concrete structure due to [ASR] because any mitigation of lost structural capacity, due to reinforcement [i.e., the chemical prestressing effect], is temporary and unpredictable.378 Furthermore, the Board found Contention C admissible as a challenge to NextEras primary rationale for not undertaking petrographic analysis: that once ASR-affected cores are removed, the behavior of those cores no longer reflects that of the confined structure.379 162.

C-10s evidence does not address the original bases pled for contentions B and C, and thus these arguments have been abandoned. However, C-10 does advocate the collective use of accelerated expansion tests, DRI, and detailed petrographic studies.380 Dr. Saouma stated that using these methods collectively would be a different way to do the job, and one that he personally considers a better way.381 But Dr. Saoumas suggestion is in the context of recommending a different ASR evaluation approach altogether. Most directly, he recommends the approach used by Hydro-Quebec (a post-tensioned facility382 unlike Seabrook Station, which is conventionally reinforced), which was a chemo-mechanical approach (at a facility that, also 377 Seabrook, CLI-18-4, 87 NRC at 94.

378 Seabrook, LBP-17-7, 86 NRC at 107.

379 Id. at 108 (citing Petition at 6-7).

380 Saouma Rebuttal § B.1 (INT028); see also Saouma Testimony §§ C.8, C.4 (item 3) (INT001-R).

381 Saouma Rebuttal § B.1 (INT028).

382 Tr. at 438; EPRI Report 3002013190, Modeling Concrete Structures Affected by Alkali Silica Reaction:

Hydro-Quebec Approach for Hydraulic and Nuclear Power Plants (Oct. 15, 2018) (NER029).

84 unlike Seabrook,383 had extensive expansion monitoring instrumentation imbedded in its structures from its inception384) intended to predict the ultimate ASR growth (i.e., extreme levels well beyond the Expansion Monitoring Limits established in the SMP). But this suggestion for an alternative approach does not identify any specific deficiency in NextEras approach.

163.

Moreover, as noted above, petrography is not needed to confirm the presence of ASR, because the SMP presumes that all cracking at Seabrook is caused by ASR.385 And to the extent C-10 argues that DRI could provide an alternative semi-quantitative method for monitoring ASR progression along the sigmoid curve, the evidence shows that the sigmoid curve advocated by Dr. Saouma is a qualitative measure, not a quantitative one.386 The Board also findsand all parties agreethat there is no consensus standard for performing DRI, and such a method presents significant challenges (e.g., subjectivity and repeatability).387 Thus, it is not obviously superior to the quantitative methods in NextEras SMP. Thus, a preponderance of the evidence demonstrates that C-10s arguments regarding additional petrography and DRI do not defeat a finding of reasonable assurance.

(2)

SMP ASR Expansion Acceptance Criteria 164.

As noted above, C-10 challenges NextEras monitoring techniques for in-plane expansion. But C-10 offers no specific challenge to either of the acceptance criteria values for 383 Tr. at 486.

384 See, e.g., EPRI Report 3002013190 at 2-9 (NER029) (The envelope of the reactor building of G2 is well instrumented with 139 extensometers installed during the construction of the plant) (emphasis added).

385 MPR Testimony at A229 (NER001); SGH Testimony at A71 (NER004).

386 See also infra Part IV.E.(3) (further discussing the sigmoid curve and accelerated expansion testing).

387 See, e.g., Saouma Testimony § C.4 (INT001-R) (I would caution that this is a delicate test that should only be performed by a very qualified petrographer, and should be performed repeatedly by the same one); MPR Testimony at A210 (NER001) (quoting FWHA Guideline § 5.3.2 (NER013)) (the results are very much related to the experience of the petrographer and since there is currently no standard test procedure available, the method is fairly subjective and the results can be quite variable from one operator to another).

85 in-plane expansion. The SMPs threshold of 0.1% in-plane expansion triggers the installation of an extensometer and a Structural Evaluation.388 This value was established based on guidelines from published literature.389 The LSTP corroborated that this value was appropriate for Seabrook, based on observations that expansion is approximately consistent in all three directions up to a certain point (when expansion reorients primarily to the through-thickness direction).390 C-10 also offers no specific challenge to the SMPs separate proprietary limit for in-plane expansion.391 This value was established from the conclusions of the LSTP anchor testing program.392 Indeed, C-10s witness acknowledged he was unqualified to testify regarding the anchor testing program.393 Thus, the preponderance ofand indeed the onlyevidence regarding the acceptance criteria values for in-plane expansion demonstrates that they are adequate to provide reasonable assurance.

165.

As noted above, C-10 challenges NextEras technique for estimating previous through-thickness expansion. But C-10 offers no specific challenge to the through-thickness or volumetric proprietary expansion limit values, themselves.394 These values were established from the conclusions of the LSTP.395 Thus, the preponderance ofand indeed the only evidence regarding the acceptance criteria values for through-thickness and volumetric expansion demonstrates that they are adequate to provide reasonable assurance.

388 SMPM, ch. 3 at 3-1.13, tbl.3-1-1 (NER007).

389 MPR Testimony at A159 (NER001).

390 Id. at A159, A180.

391 SMPM, ch. 3 at 3-1.14 (NER007); Prop. Appx, tbl.3 (NER003).

392 MPR Testimony at A159 (NER001); Prop. Appx, tbl.3 (NER003).

393 Tr. at 674 (Dr. Saouma: I confess full ignorance about anchors).

394 SMPM, ch. 3 at 3-1.14 (NER007); Prop. Appx, tbl.3 (NER003).

395 MPR Testimony at A159 (NER001); Prop. Appx, tbl.3 (NER003).

86 (3)

SMP ASR Expansion Inspection Intervals 166.

As the Commission explained, in Contention H, as admitted, C-10 challenges the frequency of proposed inspection intervals on the ground that the test program results on which the intervals are based are not representative of Seabrook concrete.396 However, the undisputed evidence demonstrates that the SMPs intervals are not based on the LSTP.397 Thus, the underlying premise of the contention is incorrect; and the intervals in the SMP are entirely detached from any alleged lack of representativeness in the LSTP. Thus, C-10s unsupported assertions regarding any alleged connection between the monitoring intervals and the representativeness of the LSTP do not defeat a finding of reasonable assurance.

167.

Furthermore, in LBP-17-7, the Board explained that the core of Contention H was C-10s challenge[ to] the monitoring intervals in Table 5 of the LAR Evaluation.398 But Dr.

Saoumas initial testimony explicitly stated that this information will be ignored by [him].399 Thus, because C-10 chose not to review this aspect of the admitted Contention, it failed to carry its burden of going forward.

168.

However, in rebuttal, Dr. Saouma raised an argument related to the monitoring intervals for the first time.400 As noted above, the Board has concluded that C-10s new rebuttal arguments (including this one) are impermissible and thus are stricken from the record. Thus, all of the evidence in this proceeding supports the adequacy of NextEras monitoring frequencies.401 396 Seabrook, CLI-18-4, 87 NRC at 94-95.

397 MPR Testimony at A188 (NER001) (None of these monitoring frequencies are based on the LSTP conclusions. Because the LSTP used accelerated aging, the LSTP conclusions are not useful for determining a time-based monitoring frequency).

398 Seabrook, LBP-17-7, 86 NRC at 123.

399 Saouma Testimony § C.3.4 (INT001-R).

400 Saouma Rebuttal § D.8.1 (INT028).

401 See, e.g., MPR Testimony A187-A193 (NER001).

87 Nevertheless, even if those arguments were permissible, a preponderance of the evidence demonstrates that none of C-10s criticisms of the SMP monitoring intervals defeats a finding of reasonable assurance.

169.

The evidence shows that NextEras SMP uses a graded monitoring approach that includes monitoring on an interval that reflects actual observed conditions.402 For locations with no symptoms of ASR (i.e., no indications of pattern cracking or water ingress), general walkdowns are performed every 5 years (for locations in harsh environments or 10 years (for locations in mild environments).403 These intervals are based on ACI 349.3R-02, Evaluation of Existing Nuclear Safety-Related Concrete Structures (NRC055). For locations with observed ASR symptoms and in-plane expansion values below 0.1%, in-plane expansion monitoring occurs every 30 months. And for locations with in-plane expansion values of 0.1% or greater, the monitoring interval for in-plane expansion, through-thickness expansion, and volumetric expansion is every 6 months. The technical basis for the 6-month monitoring frequency was addressed in NextEras response to NRC RAI-M2.404 In summary, the evidence shows this interval is consistent with the most conservative ASR inspection interval found in industry guidance, and is supported by actual data from Seabrook (see discussion above at paragraph 152 and explained further below), including trending of in-plane and through-thickness expansion measurements at dozens of locations at the plant since monitoring started in 2011.405 402 LAR Evaluation § 3.5.1, tbl.5 (INT010 (NP), NRC089 (P)); see also SMPM, ch. 2 § 1.3.1 & ch. 3 at 3-1.13, tbl.3-1-1 (NER007).

403 Harsh Environment is an area routinely subjected to one or more of the following conditions: outside ambient conditions, high moisture, humidity, very high ambient temperatures or frequent large cycling of temperatures (including freezing/thawing), frequent exposure to caustic materials, or extremely high radiation levels.

SMPM at 1-1.5 (NER007). In other words, this covers the areas most susceptible to ASR.

404 SBK-L-17156, Encl. 1 (NRC013); see also Final SE at 24-26 (discussing NRC Staffs review of NextEras response to RAI-M2).

405 MPR Testimony at A188 (NER001).

88 170.

C-10 argues that the monitoring intervals in NextEras SMP are potentially flawed. More specifically, Dr. Saouma asserts that the SMP is based on a concept of linear growth in ASR, and is invalid because ASR progress along a sigmoid curve.406 According to Dr. Saouma, it is essential that NextEra establish where each of Seabrooks structures are on that sigmoid curve in order to identify the appropriate inspection interval.

171.

As an initial matter, the sigmoid curve referenced by Dr. Saouma is illustrative only, and provides no values on either the x or y axis and thus does not represent any actual conditions at Seabrook or elsewhere. Further, C-10 provides no evidence to support its claim that the SMP inspection intervals necessarily hinge on assumptions of linear growth of ASR.

NextEra measures, trends, and analyzes actual expansions.407 This approach is consistent with the classic aging management approach endorsed by the NRC, which monitors degradation parameters against established thresholds (rather than attempting to model and predict degradation beyond the inspection intervals).408 The Board notes that the notion of trending implicitly acknowledges that the slope of a data set may change over time. And if, at any time, NextEra found that the trended expansion rates suggested a deficiency in the inspection intervals, NextEra would be required to evaluate and address this condition.409 172.

Nevertheless, the actual data from Seabrook, including trending of in-plane and through-thickness expansion measurements at dozens of locations at the plant, shows a relatively linear trend.410 This provides a significant data point indicating that Seabrooks Tier 3 locations 406 Saouma Rebuttal § D.8.1 (INT028).

407 MPR Testimony at A199 (NER001).

408 Id. at A220.

409 Tr. at 1135-37 (discussing the NUREG-0737 Operating Experience program and specific docketed commitments made to the NRC).

410 Id. at 399.

89 (i.e., the most severe) are on the central, linear part of the sigmoid curve, i.e., after initiation.411 And it is consistent with the petrography and elastic modulus measurements from Seabrooks structures, which also show locations in the active phase of ASR growth.412 But as NextEra has explainedand we agreethe information of interest for evaluations of structural adequacy (the topic of the LAR) pertains to cracking, expansion, and structural performance (which may be different than chemical progression of ASR, per se). Importantly, NextEra does have real-world information regarding these parameters at Seabrook.

173.

At the evidentiary hearing, Dr. Saouma initially claimed that a structures location on the sigmoid curve, and therefore informed selection of inspection intervals, can be only provided by an accelerated expansion test. 413 However, Dr. Saouma later corrected himself and acknowledged that other data (such as the elastic modulus measurements performed by NextEra, mentioned above) can provide this information.414 Otherwise, we find that Dr. Saoumas calls for accelerated expansion testing (which were stricken by the Board as outside the scope of this proceeding)415 identify no deficiency in the SMP. As Dr. Saouma himself acknowledged, the primary purpose of such tests is to quantify the potential for future expansion.416 But NextEras SMP does not require the knowledge of any maximum bound on potential expansion.417 Instead, the SMP relies on confirming that the structures remain within the Expansion Monitoring Limits (and any additional limits imposed by the individual Structural 411 Id. at 685.

412 Id. at 421-22.

413 Id. at 386 (emphasis added).

414 Id. at 414.

415 See supra Part IV.C.(1).

416 Tr. at 772.

417 MPR Testimony at A199 (NER001).

90 Evaluations). Further, C-10 cited no regulatory basis or aging management precedent that requires or even suggests that testing for ultimate expansion is necessary given the ongoing in situ monitoring. Accordingly, we find that the evidence does not demonstrate any practical use for accelerated expansion testing in the context of NextEras SMP (which monitors, rather than predicts, future expansion).

174.

The evidence also demonstrates that, for the highest expansion levels observed at Seabrook, and the current rates of expansion at the Tier 3 (i.e., most severe) locations, there exists decades of margin before those locations would reach a corresponding acceptance criterion.418 Those locations are monitored on a six-month frequency. As one of NextEras witnesses put it, [i]f that rate were to increase 1,000 percent in that six months, we still would be well below the limit.419 175.

The Board invited Dr. Saouma to provide testimony, or cite to evidence, that could demonstrate that NextEras six-month inspection frequency somehow could be insufficient.420 But he failed to do so.421 Ultimately, the record contains no evidencefrom Seabrook, the LSTP, academic literature, or otherwisethat indicates that NextEras inspection intervals are too long, or that ASR (unaided by chemical accelerants used in testing programs) could ever expand at a rate that would challenge these frequencies.

176.

NextEra also is subject to a requirement (through a formal license condition) to perform Periodic Expansion Assessments.422 Among other things, these Periodic Expansion 418 Tr. at 415-16.

419 Id. at 1136.

420 Id. at 418, 419.

421 Id.

422 MPR Testimony at A93 (NER001).

91 Assessments must review both the margin for future expansion and the rate at which expansion trends are approaching the acceptance criteria.423 An initial assessment was completed in 2018, with no adverse findings.424 And another assessment will be completed by 2025, and repeated every 10 years thereafter.425 Furthermore, as noted above, NextEra is subject to an ongoing obligation to evaluate the trend data regarding actual expansion rates at Seabrook and to take action independent of the Periodic Expansion Assessment if it identifies information that would challenge the appropriateness of the SMPs inspection intervals.426 177.

Based on a preponderance of the evidence, the Board finds that the SMPs inspection intervals provide reasonable assurancefor the period of time between now and 2025to ensure that potential unacceptable expansion is identified prior to reaching the acceptance criteria limits. The Board further finds that the license condition requiring Periodic Expansion Assessment in 2025, and again in 2035 and 2045, provide reasonable assurance that the inspection intervals either will be confirmed, or appropriate action will be taken by NextEra (subject to regulatory oversight) for the periods of time after 2025, 2035 and 2045, respectively.

F.

The SEM 178.

As noted above, the Board has concluded that C-10s various criticisms of the SEM were not included in the original Contention, and thus C-10s arguments on this topic are outside the scope of this proceeding. Nevertheless, even if those arguments were within scope, a preponderance of the evidence demonstrates that none of C-10s criticisms regarding the SEM defeat a finding that the SEM is appropriate for evaluating the structural adequacy of seismic 423 Id. at A94.

424 Id.

425 Id.

426 Tr. at 1135-37 (discussing the NUREG-0737 Operating Experience program and specific docketed commitments made to the NRC).

92 Category I structures at Seabrook and provides reasonable assurance for the NRC Staff to approve the LAR.

179.

By way of background, Seabrooks UFSAR specifies the method NextEra must use to evaluate the structural adequacy of seismic Category I structures at Seabrook (the Structural Evaluations). A Structural Evaluation compares the demands (i.e., load effects) on a structure to the capacities (e.g., strength or stress limits) of the structure to ensure the structure complies with the plants licensing basis (i.e., can continue to perform its intended safety function).427 180.

However, Seabrooks UFSAR did not include a method to account for ASR in Structural Evaluations. Thus, the purpose of the SEM is to provide a methodology for analyzing and evaluating seismic Category I structures with concrete affected by ASR to evaluate whether a given structure affected by ASR meets the intent of the original design codes of record and achieves the structural safety reliability indices consistent with the original design.428 NextEra considered other theoretical methods of ASR analysis, but concluded that in the absence of NRC regulations or guidance or accepted industry standards on addressing ASR in seismically-rated concrete structures, the most direct, meaningful, and reliable approach to analyzing ASR-affected structures was to firmly root the SEM in the original design basis codes.429 181.

The capacities of Seabrooks concrete structures are derived from the plants original design material properties and the applicable code expressions supporting the UFSAR.

The LSTP concluded that these originally-specified capacities can continue to be used in Structural Evaluations, so long as the Acceptance Criteria from the SMP (which provide 427 SGH Testimony at A37 (NER004).

428 Id. at A33, A34.

429 Id. at A84-A97.

93 reasonable assurance, per our finding above) are not exceeded. Thus, the LAR requested no changes to the capacity side of the Structural Evaluation calculations in Seabrooks license.

182.

As to the demand side, Seabrooks original design basis documents and UFSAR also specify the various loads and load factors that must be considered in Structural Evaluations.

Examples of loads include dead loads (the fixed weight of the structure), live loads (such as the time-varying weight of contents, e.g., temporary storage of materials), wind, earthquake effects, and temperature effects.430 Load factors are essentially multipliers applied to each load, for purposes of conservatism, to achieve a target margin of safety and reliability. The LAR requested no changes to Seabrooks existing loads and load factors. However, the LAR requested a modification of the UFSAR to incorporate an additional load (and corresponding load factor) that accounts for ASR. As explained further below in Section IV.F.(4), the codes contemplate a process such as this in which a new load is added to the minimum set of loads that are prescriptively enumerated in the code itself.

183.

The SEM provides a method for calculating that ASR load, and specifies the ASR load factor, to be used in Structural Evaluations.431 In summary, ASR loads specific to each structure are calculated from actual field data and ASR expansion measurements collected at Seabrook.432 Notably, the LSTP is unrelated to, and provides no input for, this method of calculating ASR loads or ASR load factors. The calculated ASR load and its corresponding load factor then are incorporated into the Structural Evaluations, along with the other design loads and load factors specified in the UFSAR.433 430 Id. at A51.

431 Id. at A42-A44, A51-A60.

432 Id. at A61-A71.

433 Id. at A43.

94 184.

The SEM employs a three-stage approach for Structural Evaluations.434 Each ascending stage applies more sophisticated methods and uses additional field measurement data of ASR expansion to improve the rigor of the analysis.435 For example, certain evaluations use FEM, which is a computer analysis method used by engineers to perform more complex Structural Evaluations.436 185.

Notably, the SEM also requires that Stage Three Structural Evaluations be validated against field observations and measurements (e.g., plumbness or levelness measurements) to confirm that models actually represent the in-situ conditions. For example, FEM results are correlated with the deformations, strains, and distressed areas (if any) observed at Seabrook. Thus, the simulated deformations from the Structural Evaluations are compared to the field-measured deformed shape of the structure to validate and confirm its ability to represent the current structural deformed and distressed condition.

186.

The Board concludes that the preponderance of the evidence demonstrates that the SEM is appropriate for evaluating the structural adequacy of seismic Category I structures at Seabrook and provides reasonable assurance for the NRC Staff to approve the LAR.

(1)

Individual Structural Evaluations 187.

As a preliminary matter, the Board notes that the individual Structural Evaluations performed under the SEM for the various structures at Seabrook are not, themselves, part of the LAR. NextEras LAR only sought approval of the methodology for performing those evaluations (i.e., the SEM).437 434 Id. at A47, A78-A83.

435 Id.

436 Id. at A72-A77.

437 Id. at A78.

95 188.

C-10s expert provided testimony purporting to challenge one of the individual Structural Evaluationsnamely, the Rev. 0 CEB Evaluation (a superseded version of the Structural Evaluation for the CEB).438 But as discussed above, the Rev. 0 CEB Evaluation was originally submitted to the NRC as an example of the proposed method for performing Structural Evaluations. However, the method was refined and its analysis approach was altered during the course of the NRCs review. To formalize the analysis approach used by NextEra and to provide repeatability of the analysis by a knowledgeable licensed Professional Engineer for future evaluations a methodology document was developed (i.e., the SEM Document), which served as the docketed basis for the NRCs review (and approval) of the SEM aspect of the LAR.

Likewise, the Structural Evaluation for the CEB was updated (i.e., Rev. 1) to reflect the revised and updated methodology, but was not submitted on the docket because an example was no longer needed, given the docketing of the SEM Document, and because the LAR did not request approval of the individual evaluations.

189.

Accordingly, we struck these challenges from the record as out of scope, moot, irrelevant, and immaterial, as noted in Paragraph 84 above. Nevertheless, we consider and reject each of those challenges in the sections below.439 190.

One of the key outputs of a Structural Evaluation is a customized, structure-specific Deformation Monitoring plan.440 Each plan includes unique monitoring parameters, acceptance thresholds, and monitoring intervals specific to the structure. These are separate and 438 Saouma Testimony § C.3.4.1 (INT001-R) (discussing Rev. 0 CEB Evaluation (INT015)).

439 Furthermore, even if C-10s challenges to the Rev. 0 CEB Evaluation were within the scope of this proceeding, and not mooted by the issuance of a superseded analysis, we find that the preponderance of the evidence demonstrates that Dr. Saoumas criticisms in Section 3.4.1 of his testimony (INT001-R) are meritless and do not defeat a finding of reasonable assurance, as discussed infra at Section IV.F.(5).

440 See SGH Testimony at A83 (NER004).

96 distinct from the SMP Expansion Monitoring techniques, acceptance criteria, and inspection intervals discussed above. More specifically, the Structural Evaluation outputs a Threshold Factor for each structure, which is the amount the ASR load can increase and still meet the applicable limits of the code (i.e., to remain in the linear-elastic range).441 In other words, the Threshold Factor is the margin to the limit. Future expansion of the structure is then monitored against that Threshold Factor, which is insensitive to the rate of ASR growthbecause it is merely an acceptance value.442 The Threshold Factor also informs the definition of other required monitoring and observation parameters (e.g., width of seismic isolation gaps, or distances between adjacent structures), and their corresponding limits.443 The LAR defines presumptive monitoring frequencies for these Deformation Monitoring plans, but the frequency can be adjusted on a case-by-case basis as conditions dictate.444 191.

We conclude that, because the individual Structural Evaluations are not part of the LAR, the Deformation Monitoring plans that are the outputs of the individual Structural Evaluationsand their corresponding monitoring parameters, acceptance thresholds, and monitoring intervalsalso are not subject to challenge in this proceeding.445 Moreover, C-10 presented no evidence seeking to challenge any structure-specific Deformation Monitoring plan.446 441 See id. at A81.

442 Tr. at 937-38.

443 See SGH Testimony at A83 (NER004).

444 See id.

445 In our decision admitting the Contention, we explicitly noted that the Contention does not challenge these frequencies. LBP-17-7, 86 NRC at 127.

446 Dr. Saoumas initial testimony misconstrued the Threshold Factor as being an assumed limit of future expansion. See Saouma Testimony at 24-25 (INT001-R). However, NextEra explained (and the evidence shows) that it is actually a building-specific calculated value representing remaining margin to the allowable limits of the code expressions. SGH Testimony at A102 (NER004).

97 (2)

Original Design Capacities 192.

As noted above, because ASR produces cracking in concrete, it eventually causes degradation of its material properties.447 However, as all the parties agree,448 in reinforced concrete the chemical prestressing effect causes a scenario in which this change in material properties does not correspond to a degradation of stiffness or structural capacity (and in some cases actually increases structural capacity) up to a certain level of ASR-related expansion.449 193.

The design codes used for Seabrook seismic Category I structures include methodologies to calculate structural capacities for the various limit states and loading conditions.450 Material properties are inputs to these calculations. However, as expected, laboratory testing of Seabrooks cores has shown decreases in the concrete material properties of ASR-affected structures.451 NextEra observed that calculating structural capacities using the degraded material properties for ASR-affected reinforced concrete structures would yield values that do not accurately portray the actual in situ structural capacities that exist as a result of the chemical prestressing effect.

194.

One of the key conclusions from the research performed as part of the LSTP is that Seabrooks original concrete material properties remain valid for purposes of calculating structural capacities for ASR-affected structures subject to one caveatthat the SMP Acceptance Criteria (i.e., the limits derived from the LSTP) are not exceeded.452 SGH 447 MPR Testimony at A67 (NER001); see also ISE Guideline § 4.4 at pp. 13-14 (NER012); FHWA Guidelines

§ 5.3.3 at p. 25 (NER013).

448 See, e.g., Saouma Testimony § C.2.4.1 (INT001-R).

449 MPR Testimony at A68 (NER001).

450 See LAR Evaluation § 3.2.3 (INT010 (NP), NRC089 (P)).

451 MPR Testimony at A209 (NER001).

452 See MPR-4288 (INT012 (NP), INT014 (P)).

98 independently verified this conclusion in their development of the SEM.453 Accordingly, the SEM provides that Seabrooks original material properties will be used in performing capacity calculations for the Structural Evaluations (subject to the structure meeting the SMP Acceptance Criteria).454 195.

Because the Board concluded that the LSTP yielded data appropriate for use to represent Seabrook, C-10s challenge to the use of original concrete material properties on the basis of alleged LSTP non-representativeness also fails.

196.

However, C-10 disputes this approach on other grounds as well. More specifically, Dr. Saouma generally asserts that this approach erroneously conflates material properties and structural properties.455 He further claims that it is improper to use the original material properties as inputs to FEMs, given that those material properties now are degraded due to ASR. But C-10 presents no evidence that this broader theoretical challenge to NextEra approach somehow is related to the representativeness of the LSTP.456 Accordingly, as noted in Paragraph 83 above, we struck these arguments from the record. Nevertheless, we considered these arguments and find that they also fail on the merits.

197.

The Board notes that C-10 does not dispute the overarching principle that structural capacity is not degraded by ASR. In fact, Dr. Saouma admits that [m]any tests have shown an increase in structural shear strength in reinforced concrete beams (through the so-called prestressing effect) because of ASR.457 And Dr. Saouma appears to agree that the reason 453 SBK-L-018074, Encl. 5 (NRC015) (NextEras response to NRC RAI-D10).

454 SEM Document at 4 (INT022).

455 Saouma Testimony § C.2.4 (INT001-R).

456 The plain language of the Contention, by its own terms, makes clear that challenges to the LAR must purport to be the result of the alleged non-representativeness of the LSTP.

457 Saouma Testimony § B.1 (INT001-R).

99 NextEra can calculate capacities without accounting for the deterioration due to ASR is because of the LSTP results showing that there was no deterioration in the she[a]r strength.458 Dr. Saouma notes that without conducting the LSTP NextEra would not be able to use the original material properties.459 But the fact remains that NextEra did conduct the LSTP; and the conclusions of that research demonstrate, across tens of thousands of pages of technical justification, that NextEra is able to use the original material properties (provided that the expansions remain within the Expansion Monitoring Limits).

198.

C-10 presents no evidence to suggest that the LSTPs overarching conclusion that structural capacity is not degraded due to ASR expansion, up to the limits of the testingis flawed or incorrect. And Dr. Saouma identified no published literature or independent research or analysis to contradict NextEras approach. In contrast, NextEras approach is based on scientific research in the LSTP, as confirmed by sound structural engineering principles, which are extensively documented in the record and independently verified by SGHs confirmatory analysis. Thus, the preponderance of the evidence demonstrates that the use of Seabrooks original material properties in performing capacity calculations for the Structural Evaluations (subject to the structure meeting the SMP Acceptance Criteria) is adequate to provide reasonable assurance.

(3)

ASR Loads and Load Factors 199.

As noted above, the SEM provides a method for calculating ASR load, and specifies the ASR load factor, to be used in Structural Evaluations.460 The ASR loads (specific to each structure) are calculated from Seabrook field measurements, which is entirely separate 458 Tr. at 973.

459 Id.

460 SGH Testimony at A42-A44, A51-A60 (NER004).

100 and disconnected from the LSTP.461 Thus, even assuming some portion of the SEM was within the scope of this proceeding, this portion (related to ASR loads and load Factors) clearly would not be because it is unrelated to the Contention admitted for adjudication in this proceeding, which pertains solely to the representativeness of the LSTP.

200.

Dr. Saouma initially challenged this aspect of the SEM, claiming that [t]he assumption that ASR can be considered a load is fundamentally wrong.462 However, he later rescinded that remark and acknowledged there is no controversy on this point.463 Dr. Saouma also suggested that the use of crack width indexing (i.e., the Seabrook field measurements) to calculate ASR loads and load factors rendered this aspect of the SEM unreliable.464 As we concluded above, crack width indexing is adequate to provide reasonable assurance. And after further reviewing the technical basis, Dr. Saouma stated that he salute[s] NextEras effort in developing the ASR loads and load factors.465 Dr. Saouma noted for the record that he do[es]

not disagree with this aspect of NextEras methodology, but rather contests the manner in which it was applied (i.e., in a code-based analysis).466 201.

Ultimately, C-10 presents no evidence to contradict NextEras code-based approach to ASR loads and load factors. Thus, the preponderance of the evidence demonstrates that the SEM approach to ASR loads and load factors is adequate to provide reasonable assurance.

461 Id. at A61-A71.

462 Saouma Testimony § C.2.4.2 (INT001-R).

463 Tr. at 440.

464 Saouma Testimony § C.11 (INT001-R).

465 Tr. at 440-41. (Dr. Saouma observing that this aspect of the LAR was independently reviewed by Dr.

Ellingwood, who concluded that the approach was sound, and noting that he respects and defers to Dr.

Ellingwoods expert opinion.)

466 Saouma Rebuttal § A.12 (INT028).

101 (4)

Code-Based Structural Evaluation Approach 202.

As noted above, NRC regulations at 10 C.F.R. § 50.92(a) state that, in determining whether to approve a license amendment request, [t]he Commission will be guided by the considerations which govern the issuance of [the] initial license[]... to the extent applicable and appropriate.

203.

As the NRC Staff explained, Seabrooks LAR approach of using the Structural Evaluation methods in ACI 318-71 and ASME 1975 were deemed applicable because they are part of Seabrooks existing licensing basis code of record for performing Structural Evaluations on seismic Category I structures.467 C-10 also agrees that these codes are applicable.468 204.

As the NRC Staff explained, Seabrooks LAR approach of using the Structural Evaluation methods in ACI 318-71 and ASME 1975 were deemed appropriate because NextEra provided a robust technical basis, supported by the LSTP, demonstrating that the existing codes could continue to be used for Structural Evaluations of ASR-affected structures.469 C-10, however, disagrees.470 Its expert suggests that codes, in general, cannot be used to analyze structures affected by ASR,471 and that only probabilistic and constitutive modeling (i.e., beyond code) methods would qualify as appropriate.472 However, as noted above, the Board has stricken C-10s arguments regarding alternative means of regulatory compliance. Nevertheless, the Board has considered the appropriateness of ACI 318-71 and ASME 1975, as explained below.

467 Tr. at 336.

468 Id. at 337.

469 Id. at 336.

470 Id. at 337.

471 Saouma Rebuttal § B.1 (INT028) (suggesting that code-based approaches can only scratch at the problem);

Tr. at 1065 (Dr. Saouma: code code code [speaking derisively regarding the use of consensus engineering codes]).

472 See, e.g., Saouma Testimony §§ C.5 to C.8 (INT001-R).

102 205.

Neither ACI 318-71 or ASME 1975 contain a prescriptive method of accounting for ASR in Structural Evaluations. But this is not dispositive of the appropriate[ness] of these codes. In fact, it is not uncommon that a new load or a new phenomenon, not otherwise explicitly addressed in the four corners of a code, must be evaluated.473 And the codes permit and indeed anticipatethat new loads will be evaluated.474 For example, ACI 318-71 indicates that the prescribed loads specified in the code are the minimum set of loads that must be evaluated in Structural Evaluations, as opposed to an exhaustive list.475 Indeed, consistent with NUREG-0800 § 3.8.4, Seabrooks licensing basis (UFSAR Table 3.8-16 (NRC007)) requires NextEra to use ACI 318-71 to evaluate other loads and phenomena not specifically enumerated in ACI 318-71, such as operational piping loads (RO) and accident pressure (Pa).476 Ultimately, we find that the absence of explicit ASR provisions in ACI 318-71 and ASME 1975 has no bearing on whether they are appropriate for use in the LAR.

206.

Dr. Saouma criticizes the use of ACI 318-71 and ASME 1975 as inappropriate primarily because they employ linear-elastic analysis.477 By way of background, linear-elastic structural behavior refers to the general load-deformation behavior of a reinforced concrete structure in which, as the load increases, the structure deforms proportionately (i.e., linearly), and when the load decreases, the structure recovers to the point of zero deformation in the same linear fashion (i.e., elastic behavior).478 If a structure is loaded beyond the limits of linear-elastic behavior, its deformation increases faster than the load increases, which is called non-linear (i.e.,

473 Tr. at 1105.

474 Id. at 1004 475 Id. at 577-79; ACI 318-71 §§ 8.21, 9.3.2, 9.3.7 (NRC049).

476 See also Tr. at 578.

477 Saouma Testimony § B.7 (INT001-R).

478 SGH Testimony at A93 (NER004).

103 plastic) behavior.479 Dr. Saouma asserts that ASR could ultimately cause non-linear structural behavior, and that only a non-linear analysis method can evaluate non-linear behavior.480 207.

One of the key differences between code-based linear and nonlinear analysis methods is that linear analyses use conservative code limits in order to streamline and simplify the analysis, whereas nonlinear analyses apply more granular methods and use additional input parameters where refinement is necessary to demonstrate compliance with the codes.481 For example, if a structure is predicted to experience highly nonlinear behavior, it may not be able to demonstrate satisfaction of conservative code limits via linear analysis; thus, a nonlinear analysis may be appropriate. The question is thus, what is the appropriate tool for the job? We find that a preponderance of the evidence supports NextEras conclusion that linear-elastic analysis remains the appropriate tool for evaluating structural adequacy in Seabrooks seismic Category I structures.

208.

Under normal operating conditions, Seabrooks license requires, as a matter of law, that plant structures shall be maintained within elastic limits.482 For Seabrooks seismic Category I structures other than the Containment Building, ACI 318-71 provides a means to evaluate low levels of localized nonlinearity and still demonstrate compliance with the limits of elastic structural behavior.483 Thus, to the extent C-10 claims NextEras analysis method cannot account for low levels of localized nonlinearity, it is factually mistaken. And to the extent C-10 argues Seabrooks structures will experience high levels of, or non-localized, nonlinearity, it 479 Id.

480 Saouma Testimony § B.3 (INT001-R).

481 Tr. at 304, 585-86.

482 Final SE at 48 (INT024 (NP), INT025 (P)) (quoting Seabrook UFSAR §§ 3.8.4.3, 3.8.4.5, 3.8.3.3, 3.8.3.5).

483 Tr. at 865, 869. We reject Dr. Saoumas claim that a single localized point of low-level nonlinearity will cause the structure to go [c]aput. Id. at 870.

104 provides no evidentiary supportand its claim is contradicted by NextEras evidence. More specifically, NextEra submitted a detailed analysis in response to an NRC RAI which demonstrated that, under realistic normal operating conditions, with an operating basis earthquakei.e., a very high level conservative earthquake484Seabrooks seismic Category I structures still would remain within the elastic range.485 Given this clear and legally-enforceable requirement that Seabrooks structures can only incur loading (including loading from ASR) up to the limits of linear-elastic structural behavior, and the fact that NextEra routinely monitors the margin of ASR expansion remaining to these limits (i.e., the Threshold Factor), we find the record presents no basis to conclude that the linear-elastic analysis methods in ACI 318-71 in ASME 1975 would be inappropriate.

209.

At the evidentiary hearing, Dr. Saouma further criticized NextEra regarding the appropriateness of using Seabrooks existing codes of record, suggesting that NextEra blindly accept[ed] the code.486 But Mr. Bells testimony provided a succinct summary of the evidence that rebuts this assertion:

There has been an enormous amount of work that has gone in through the testing program and our analysis to validate the approach that we have taken. Its not blind at all. It is carefully considered. The validity of the code equations were amply demonstrated by the very extensive testing of the large scale testing program.487 210.

In contrast to the extensive testing of the large scale testing program, C-10 provides no evidence, other than Dr. Saoumas opinion, that ACI 318-71 and ASME 1975 are not appropriate for use in the LAR. On balance, we find that NextEra has provided the 484 Tr. at 860.

485 SBK-L-17204, Encl. 1 (NRC014) (response to NRC RAI-D8).

486 Tr. at 581.

487 Id. at 582.

105 preponderance of the evidence on this point, and conclude that Seabrooks codes of record are applicable and appropriate, as required by 10 C.F.R. § 50.92.

(5)

Criticisms Specific to the Rev. 0 CEB Evaluation 211.

As noted above, even if C-10s challenges to the Rev. 0 CEB Evaluation were within the scope of this proceeding, and even if they were not mooted by the issuance of a superseded analysis, we find that the preponderance of the evidence demonstrates that Dr.

Saoumas criticisms in Section 3.4.1 of his testimony (INT001-R) are meritless. As a general matter, these criticisms are far afield from the Contentions key issue of LSTP representativeness. Moreover, they are based in large part on Dr. Saoumas misunderstandings of the LARand indeed, the differences between various Seabrook structures488that are either clearly contradicted by the record evidence in this proceeding, or that C-10s rebuttal testimony abandoned (after NextEras testimony highlighted and corrected Dr. Saoumas error). As further discussed below, these meritless arguments do not defeat a finding of reasonable assurance.

a.

Thermal Expansion & Shell Elements 212.

C-10 criticizes the use of thermal expansion and shell elements in the Rev. 0 CEB Evaluation FEM.489 More specifically, Dr. Saouma asserts that shell elements cannot capture the through thickness expansion, and that the use of thermal expansion will fail to capture the anisotropic nature of the expansion.490 In essence, Dr. Saoumas criticisms are two-fold. First, Dr. Saouma claims that the FEM uses isotropic thermal expansion (i.e., the same 488 Dr. Saouma repeatedly conflated the CEB with the Containment Building in his written and oral testimony.

See, e.g., Tr. at 614-15, 858-59. These are two different structures, with different intended safety functions and licensing bases, the structural evaluations of which are governed by entirely separate code provisions. SGH Testimony at A36, A59 (NER004) (noting the CEB reference code is ACI 318-71, whereas the Containment Building is governed by ASME 1975). Dr. Saoumas confusion informs the weight we give to his testimony in this area.

489 Saouma Testimony at 26 (INT001-R).

490 Id.

106 value for each direction of expansion), whereas it should be using elements with orthotropic expansions capable of defining unique expansion values for each direction in the model. And second, Dr. Saoumas concern is that the FEM is only modeling expansion in the two in-plane directions, whereas ASR also may cause through-thickness expansion. As a preliminary matter, we note that neither of these criticisms stem from the alleged non-representativeness of the LSTP and were never discussed or mentioned in C-10s original proposed contention, and thus are beyond the scope of the Contention. Further, as noted above in Section IV.C., the Rev. 0 CEB Evaluation (and structure-specific evaluations generally) are not within the scope of the challenged license amendment. Nevertheless, as explained below, we consider and reject these criticisms.

213.

First, the evidence shows that the Rev. 0 CEB Evaluation, in fact, used unique input values for each direction in the FEM, entirely disproving Dr. Saoumas contrary assertion.491 By way of background, FEM codes do not include direct input fields for ASR expansion, but thermal expansion can be used as a proxy in the software.492 Thus, in the Rev. 0 CEB Evaluation, ASR expansion is simulated by applying a thermal expansion to the elements representing the CEB concrete.493 More specifically, [s]imulated ASR expansion of the CEB is based on Crack Index (CI) strain measurements performed in the regions of the structure defined in Table 13.494 Dr. Saoumas criticism appears to conflate the concept of Crack Index (CI) values, which are unidirectional, and Combined Crack Index (CCI) values, which 491 Tr. at 1183 (Dr. Saouma curtly stating that Its not there.); see also id. at 1171-73.

492 SGH Testimony at A76 (NER004).

493 Rev. 0 CEB Evaluation at 40 (INT015).

494 Id. at 79.

107 represent a combination of the vertical and horizontal CI measurements.495 In other words, the two CI values (horizontal and vertical measurements) are not combined for use in the FEM. And Table 13 of the Rev. 0 CEB Evaluation further confirms that unique expansion values were used for each direction.496 Thus, Dr. Saoumas criticism is not supported by the evidence.

214.

Second, NextEra explained that the purpose of the FEM is to capture the load effects of ASR expansion, not to predict the dimensional level of expansion.497 C-10 did not dispute this assertion. Accordingly, NextEras experts testified that, if the in-plane inputs are bounding the load effects captured in the FEM will be appropriately conservative.498 Notably, the below-grade portions of the CEB have tri-axial reinforcement499so ASR will not expand preferentially in the through-thickness direction in those areas. And even in the upper portions of the CEB without tri-axial reinforcement, the evidence show that through-thickness deformation is very small compared to in-plane.500 And this observation is no surprise, given that the CEB shell is a thin-shell structure (thickness ranges from 15-36) whereas the in-plane dimensions of that shell are many orders of magnitude greater.501 C-10 did not dispute NextEras assertion that the in-plane inputs are bounding.

495 SEM Document at 6 (NER022) (The Combined Cracking Index (CCI) is the weighted average of the CI in the two measured in-plane directions. A typical ASR-monitoring location produces two CI values (in-plane perpendicular directions) and one CCI value).

496 Rev. 0 CEB Evaluation at 93, tbl.13 (INT015) (showing the separate hoop (i.e., horizontal) and meridional (i.e., vertical) CI measurements used in the FEM); id. tbl.12 (providing the separate hoop and meridional values for each monitoring location). See also SEM Document § 3.1 (NER022) (confirming that the SEM specifies the use of CI, not CCI).

497 SGH Testimony at A73, A110 (NER004).

498 Id.

499 Id at A107.

500 Id.

501 Id.

108 215.

Third, NextEras evidence demonstrates that solid elements (i.e., three-dimensional elements recommended by Dr. Saouma in lieu of shell elements) are used in the FEM for the portions of the CEB in which through-thickness expansion is relevant and material.502 For example, the Rev. 0 CEB Evaluation uses solid (3-D) elements to capture the CEBs ring-shaped foundation, which is a thick member.503 C-10 did not comment on this distinction.

216.

On balance, we find that NextEras selection of shell elements and solid elements for different portions of the CEB was appropriate in the context of the FEMs purpose (to capture load effects), and that the FEM appropriately used unique thermal expansion input values for each direction.

b.

Bubble Expansion 217.

Dr. Saouma also claimed that the Rev. 0 CEB Evaluation failed to account for bubble expansion that will occur on the CEB base mat.504 The record contains no evidence that this criticism stems from the alleged non-representativeness of the LSTP, and again this issue was not described or mentioned in the original proposed contention. Thus, it is beyond the scope of the Contention. Nevertheless, we consider and reject this criticism because NextEras evidence clearly showsand we agreethat the CEB foundation is a ring, not a mat, and thus Dr. Saoumas assertion regarding alleged bubble expansion of a non-existent base mat is not applicable to the CEB.505 502 Id.

503 Id.

504 See Saouma Testimony at 26, 27-28, and fig.16a (INT001-R).

505 SGH Testimony at A108 & fig.12 (NER004).

109

c.

Steel Membrane Elements 218.

C-10 criticizes the Rev. 0 CEB Evaluation because steel membrane elements were included only for the ASR study and not for the other load cases, and suggests this is somehow improper.506 The record contains no evidence that this criticism stems from the alleged non-representativeness of the LSTP and was not raised in the original contention. Thus, it is beyond the scope of the Contention. Nevertheless, we consider and reject this criticism.

219.

NextEras responsive testimony showed that C-10s claim that steel membrane elements were used only for the evaluation of ASR loads was factually inaccurate.507 Steel membrane elements also were included in modeling concrete swelling strains.508 NextEras responsive testimony also explained that this distinction was necessary and appropriate because the concrete and reinforcing steel strain differently in the assessment of ASR loads and swelling strains (compared to modeling for other loads), and thus should be modeled separately, consistent with ACI 318-71.509 C-10 did not contest, and offered no rebuttal to, this assertion.

Thus, we find that a preponderance of the evidence shows NextEras use of steel membrane elements was reasonable and appropriate.

d.

Swelling 220.

C-10 criticizes the Rev. 0 CEB Evaluation because it used moisture-related swelling values that Dr. Saouma called arbitrary and without scientific basis.510 Again, the record contains no evidence that this criticism stems from the alleged non-representativeness of 506 See Saouma Testimony at 26 (INT001-R).

507 SGH Testimony at A111 (NER004).

508 Id.

509 Id. (citing ACI 318-71 ¶ 8.5.3.1 (NRC049)).

510 Saouma Testimony at 26-27 (INT001-R).

110 the LSTP or mentioned in the original contention, and therefore is beyond the scope of the Contention. Nevertheless, we consider and reject this criticism. NextEra cited several sources of scientific research that provided the technical justification for the swelling values it used.511 C-10 offered no rebuttal to the accuracy or appropriateness of this information. Thus, we find that a preponderance of the evidence shows the swelling values used in the Rev. 0 CEB were reasonable and appropriate.

e.

Seismic Analysis 221.

C-10 criticized the Rev. 0 CEB Evaluation for performing a seismic response spectra analysis using the stick method.512 Dr. Saouma criticized this method as a model of the past that is overly simplistic.513 Dr. Saouma also criticizes the analysis for allegedly confusing in-plane and out-of-plane shear, and improperly assuming that cracking can only occur in the direction of seismic excitation.514 But the record contains no evidence that the criticisms are in any way related to the alleged non-representativeness of the LSTP nor were they mentioned in the original contention. Thus, they are beyond the scope of the Contention.

Notwithstanding, we consider and reject these criticisms.

222.

As a preliminary matter, the evidence shows the Rev. 0 CEB Evaluation uses the multi-step method, not merely the stick method.515 Indeed, contrary to Dr. Saoumas impression that such methods are outdated, thats what Seabrooks existing licensing basis 511 SGH Testimony at A113 (NER004).

512 See Saouma Testimony at 27 (INT001-R).

513 See id.

514 See id. at 28.

515 SGH Testimony at A114 (NER004) (The multi-step method applies seismic accelerations calculated from the lumped-mass stick model, Step 1, to a more detailed model, Step 2, for calculating structural forces for evaluation).

111 explicitly requires.516 Accordingly, we find no merit in Dr. Saoumas assertion that either the stick method or the multi-step method are outdated and therefore inappropriate. In practical terms, both methods continue to be endorsed in the NRCs Standard Review Plan, which was updated in 2013, and in ASCE 4-16, which was published in 2016.517 In fact, the stick method was recently approved by the NRC for use in two new nuclear power units.518 223.

Furthermore, as to Dr. Saoumas assertion that the seismic analysis conflates in-plane and out-of-plane shear, NextEras experts testified that Dr. Saoumas arguments appear to conflate the LSTP testing with the Rev. 0 CEB Evaluation.519 The evidence shows that the Rev. 0 CEB Evaluation did not conflate the in-plane and out-of-plane shear because they were evaluated separately in the detailed FEM at both the element level and the section cut level.520 C-10 failed to rebut, either in Dr. Saoumas Rebuttal Testimony or at the evidentiary hearing, NextEras responses on this topic; C-10 also failed to rebut NextEras responses to Dr. Saoumas other minor criticisms related to the Rev. 0 CEB Evaluation seismic analysis).521 516 SGH Testimony at A114 (NER004).

517 SRP § 3.7.2 at 11 (Rev. 4, Sept. 2013) (NER043); ASCE 4-16 § 3.1.2 (NER036).

518 SGH Testimony at A114 (NER004) (discussing the combined operating license for South Texas Project, Units 3 & 4).

519 Id. at A120.

520 Id. at A121. As a practical matter, NextEras evidence also provides a technical analysis showing that in-plane cracking is unlikely due to low seismic motion at Seabrook. SGH Testimony at A122 (NER004). C-10 also did not rebut this assertion.

521 Compare Saouma Testimony at 27 (INT001-R) (asserting the method did not account for seismic contact between the wall and the adjacent soil) with SGH Testimony at A114 (NER004) (explaining the dynamic soil pressure is explicitly considered in the analysis, based on the pressure profiles is described in Seabrooks UFSAR § 3.7(B).2). Compare Saouma Testimony at 29 & fig.17 (INT001-R) (challenging NextEras use of fixed-base analysis and arguing ASCE 4-16 requires soil structure interaction (SSI) analysis) with SGH Testimony at A115 (NER004) (explaining that Seabrook structures are founded on hard rock with shear wave velocity of 8,000 to 10,000 ft/sec, see UFSAR Section 2.5.2.5 (NER044), and that ASCE 4-16 and the SRP specify that fixed base analysis is appropriate (and no SSI analysis is necessary) when the shear wave velocity is greater than 8,000 ft/sec, see ACI 4-16 § 5.1.1(a)(3) (NER036); SRP § 3.7.2 (NER043)).

112 224.

In contrast, Dr. Bolourchi, a structural engineer and seismic expert who has performed seismic analyses for many nuclear power plants in the United States across his four decades of experience in this area, provided testimony that NextEras method is entirely acceptable and appropriate.522 Based on the evidentiary record, the Board finds that Dr.

Saoumas claims are unsupported, and that a preponderance of the evidence supports the appropriateness of NextEras method of seismic analysis.

f.

Section Cut Approach 225.

C-10 criticizes the section cut approach used in the Rev. 0 CEB Evaluation.

More specifically, in his initial testimony, Dr. Saouma claimed this approach reduces the assessment to a series of parallel column[s] with no interaction among them.523 In essence, Dr.

Saouma asserts that the inputs to NextEras FEM are not granular enough to capture structural behavior. But the record contains no evidence that this criticism was raised in the original Contention or is in any way related to the alleged non-representativeness of the LSTP. Thus, it is beyond the scope of the Contention. Notwithstanding, we consider and reject this criticism.

226.

In its testimony, NextEra demonstrated that the section cut approach (as used in the Rev. 0 CEB Evaluation) actually uses the results from the FEM, with all of its connectivity, properties, loading, and boundary conditions.524 More specifically, the output from a series of consecutive elements is aggregated to a load over a length (so called section cut) and compared to the capacity across the length of the section cut.525 NextEra pointed to information in the Rev. 0 CEB Evaluation itself showing that the section cuts are simply selections from the 522 See, e.g., SGH Testimony at A114-15, A120-22 (NER004).

523 See Saouma Testimony at 28 (INT001-R).

524 SGH Testimony at A116 (NER004).

525 Id.

113 finite element model (not a series of isolated clusters of elements) designed to capture the peak demand in a particular portion of the structure.526 NextEras experts testified that the section cut approach captures the actual structural response,527 and that this approach is fully consistent with the ACI code.528 227.

C-10 failed to rebut, either in Dr. Saoumas Rebuttal Testimony or at the evidentiary hearing, NextEras explanation. Accordingly, we find C-10s claims unpersuasive, and we find that a preponderance of the evidence supports the appropriateness of NextEras use of the section cut approach.

V.

SUMMARY

FINDINGS OF FACT AND CONCLUSIONS OF LAW 228.

Based upon a review of the entire record of this proceeding and the proposed findings of fact and conclusions of law submitted by the parties, and based upon the findings set forth above, which are supported by reliable, probative, and substantive evidence in the record, the Board has decided all matters in controversy as to the admitted Contention and the reaches the following conclusions.

229.

The Board concludes that NextEras Second MIL should be granted for the reasons articulated above in Section IV.C.

230.

The Board finds that C-10 has not satisfied its initial burden of going forward on the Contention because it has failed to provide sufficient probative evidence to establish a prima facie case for any of the Commission-summarized elements of the Contention presented 526 Id. & fig. 13 (consolidating figures from Rev. 0 CEB Evaluation, App. N figs. N-2, N-7, & N-11 (INT015)).

527 Id.

528 Id. at A117, A118 (NER004).

114 by C-10 at the outset of this proceeding. Thus, the Board concludes that the Contention is resolved in favor of NextEra.

231.

We find that, even if C-10 had satisfied its initial burden of going forward on the Contention, NextEra has demonstrated, by a preponderance of the evidence, through the MPR Testimony, the SGH Testimony, and corresponding exhibits, that its program for addressing Seabrooks slow-growing version of ASR (which, after more than thirty years, has reached only low to moderate levels)529 is robust, conservative, technically justified, and satisfies the reasonable assurance standard. Importantly, the NRCs reasonable assurance standard does not require that the LAR satisfy an absolute or beyond a reasonable doubt standard.530 And as noted above, [t]he mere casting of doubt on some aspect of an application is legally insufficient to defeat a finding of reasonable assurance.531 Thus, even assuming C-10 had submitted sufficient probative evidence to move forward on the Contentionwhich it has notthat evidence is wholly insufficient to overcome the evidence submitted by NextEra, or to defeat the NRCs finding of reasonable assurance.

232.

More specifically, the Board finds that a preponderance of the evidence demonstrates that: (1) the LSTP yielded representative data that are appropriate for use to represent ASR-affected concrete at Seabrook, (2) the SMP is adequate to monitor the progression of ASR at Seabrook, (3) the SEM is appropriate for evaluating the structural adequacy of seismic 529 Id. at A90 (NER004).

530 Oyster Creek, CLI-09-7, 69 NRC at 262 n.142; Zion Station, ALAB-616, 12 NRC at 421; N. Anna Envtl.

Coal., 533 F.2d at 667-68 (rejecting the argument that reasonable assurance requires proof beyond a reasonable doubt and noting that the licensing board equated reasonable assurance with a clear preponderance of the evidence).

531 PFS, CLI-00-13, 52 NRC at 31 (citing LES, CLI-97-15, 46 NRC 297 (1997); Seabrook, CLI-99-6, 49 NRC at 222).

115 Category I structures at Seabrook, (4) reasonable assurance exists for the NRC Staff to grant the LAR, and (5) C-10s criticisms of the LAR do not defeat a finding of reasonable assurance.

233.

In Contention D, C-10 challenged the representativeness of the data from the LSTP. In Contentions A, B, and C, C-10 challenged the effectiveness of monitoring techniques at Seabrook based on the alleged non-representativeness of the LSTP. And in Contention H, C-10 challenged the frequency of the proposed monitoring intervals at Seabrook based on the alleged non-representativeness of the LSTP. Because the Board finds that the LSTP yielded representative data that are appropriate for use to represent ASR-affected concrete at Seabrook, we conclude that each of these contentions, and the reformulated Contention, are resolved in favor of NextEra.

234.

Overall, we find that a preponderance of the evidence supports the NRC Staffs conclusion that the LARs plant-specific method of evaluation for seismic Category I reinforced concrete structures affected by ASR at Seabrook is acceptable and provides reasonable assurance that these structures continue to meet the relevant requirements of 10 CFR Part 50, Appendix A, General Design Criteria (GDC) 1, 2, 4, 16 and 50, and 10 CFR Part 50, Appendix B; and that NextEra has satisfied the requirements of 10 C.F.R. §§ 50.92 and 50.57(a)(3) and (6).

VI.

ORDER WHEREFORE, IT IS ORDERED, pursuant to 10 C.F.R. §§ 2.1210, that the Contention is resolved on the merits in favor of NextEra.

IT IS FURTHER ORDERED, this Initial Decision will constitute a final decision of the Commission forty (40) days from the date of issuance (or the first agency business day following that date if it is a Saturday, Sunday, or federal holiday, see 10 C.F.R. § 2.306(a)), unless a petition for review is filed in accordance with 10 C.F.R. § 2.1212, or the Commission directs otherwise.

116 IT IS FURTHER ORDERED that any party wishing to file a petition for review on the grounds specified in 10 C.F.R. § 2.341(b)(4) must do so within twenty-five (25) days after service of this Initial Decision. The filing of a petition for review is mandatory for a party to have exhausted its administrative remedies before seeking judicial review. Within twenty-five (25) days after service of a petition for review, parties to the proceeding may file an answer supporting or opposing Commission review. Any petition for review and any answer shall conform to the requirements of 10 C.F.R. § 2.341(b)(2)-(3).

Executed in Accord with 10 C.F.R. § 2.304(d)

Respectfully submitted, Executed in Accord with 10 C.F.R. § 2.304(d)

Steven Hamrick, Esq.

NextEra Energy Seabrook, LLC 801 Pennsylvania Ave., NW Suite 220 Washington, D.C. 20004 Phone: (202) 349-3496 Fax: (202) 347-7076 E-mail: steven.hamrick@fpl.com Paul M. Bessette, Esq.

Morgan, Lewis & Bockius LLP 1111 Pennsylvania Avenue, N.W.

Washington, D.C. 20004 Phone: (202) 739-5796 Fax: (202) 739-3001 E-mail: paul.bessette@morganlewis.com Signed (electronically) by Ryan K. Lighty Ryan K. Lighty, Esq.

Morgan, Lewis & Bockius LLP 1111 Pennsylvania Avenue, N.W.

Washington, D.C. 20004 Phone: (202) 739-5274 Fax: (202) 739-3001 E-mail: ryan.lighty@morganlewis.com Counsel for NextEra Energy Seabrook, LLC Dated in Washington, DC this 21st day of November 2019

DB1/ 109860137.6 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of:

NEXTERA ENERGY SEABROOK, LLC (Seabrook Station Unit 1)

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Docket No. 50-443-LA-2 November 21, 2019 CERTIFICATE OF SERVICE Pursuant to 10 C.F.R. § 2.305, I certify that, on this date, the foregoing NextEra Energy Seabrook LLCs Proposed Findings of Fact and Conclusions of Law was served upon the Electronic Information Exchange (the NRCs E-Filing System), in the above-captioned proceeding.

Signed (electronically) by Ryan K. Lighty Ryan K. Lighty, Esq.

Morgan, Lewis & Bockius LLP 1111 Pennsylvania Avenue, N.W.

Washington, D.C. 20004 Phone: (202) 739-5274 Fax: (202) 739-3001 E-mail: ryan.lighty@morganlewis.com Counsel for NextEra Energy Seabrook, LLC