Mr. Eric McCartney 

Site Vice President 

Seabrook Station 

NextEra Energy 

626 Lafayette Rd. 

Seabrook, NH 03874 

UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

WASHINGTON, D.C. 20555-0001 

September 19, 2016 

SUBJECT: SEABROOK STATION, UNIT NO. 1 -SUPPLEMENTAL INFORMATION 

NEEDED FOR ACCEPTANCE OF REQUESTED LICENSING ACTION 

RE: ALKALI-SILICA REACTION (CAC NO. MF8260) 

Dear Mr. McCartney: 

By letter dated August 1, 2016, NextEra Energy Seabrook, LLC (NextEra) submitted a license 

amendment request for the Seabrook Station, Unit No. 1. The proposed amendment would 

revise the Seabrook Updated Final Safety Analysis Report to include methods for analyzing 

seismic Category I structures with concrete affected by an alkali-silica reaction. The purpose of 

this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staff's 

acceptance review of this amendment request. The acceptance review was performed to 

determine if there is sufficient technical information in scope and depth to allow the NRC staff to 

complete its detailed technical review. The acceptance review is also intended to identify 

whether the application has any readily apparent information insufficiencies in its 

characterization of the regulatory requirements or the licensing basis of the plant. 

Consistent with Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), an 

amendment to the license (including the technical specifications) must fully describe the 

changes requested, and following, as far as applicable, the form prescribed for original 

applications. Section 50.34 of 10 CFR addresses the content of technical information required. 

This section stipulates that the submittal address the design and operating characteristics, 

unusual or novel design features, and principal safety considerations. 

The NRC staff has reviewed your application and concluded that the information delineated in 

the enclosure to this letter is necessary to enable the staff to make an independent assessment 

regarding the acceptability of the proposed amendment in terms of regulatory requirements and 

the protection of public health and safety and the environment. 

In order to make the application complete, the NRC staff requests that NextEra supplement the 

application to address the information requested in the enclosure by October 3, 2016. This will 

enable the NRC staff to begin its detailed technical review. If the information responsive to the 

NRC staff's request is not received by the above date, the application will not be accepted for 

review pursuant to 1 O CFR 2.101, and the NRC will cease its review activities associated with 

the application. If the application is subsequently accepted for review, you will be advised of 

any further information needed to support the staff's detailed technical review by separate 

correspondence. 
E. McCartney - 2 -

The information requested and associated timeframe in this letter were discussed with 

Mr. Ken Browne of your staff on September 14, 2016. 

If you have any questions, please contact me at (301) 415-2048 or Justin.Poole@nrc.gov. 

Docket No. 50-443 

Enclosure: 

Supplemental Information Needed 

cc w/enclosure: Distribution via Listserv 

Justin C. Poole, Project Manager 

Plant Licensing Branch 1-2 

Division of Operating Reactor Licensing 

Office of Nuclear Reactor Regulation 
Background 

SUPPLEMENTAL INFORMATION NEEDED 

AMENDMENT REQUEST REGARDING ALKALI-SILICA REACTION 

NEXTERA ENERGY SEABROOK. LLC 

SEABROOK STATION, UNIT NO. 1 

DOCKET NO. 50-443 

By letter dated August 1, 2016 (Agencywide Documents Access and Management System 

(ADAMS) Accession No. ML 16216A240), NextEra Energy Seabrook, LLC (NextEra) submitted a 

license amendment request (LAR) to revise its current licensing basis to adopt a methodology for 

the analysis of seismic Category I structures with concrete affected by alkali-silica reaction (ASR). 

The proposed amendment would revise the Seabrook Updated Final Safety Analysis Report 

(UFSAR) to include new methods for analyzing seismic Category I structures with concrete 

affected by ASR. 

As discussed in Section 4.3.8.2, Guidance for Changing from One Method of Evaluation to 

Another," of Nuclear Energy Institute (NEI) 96-07, Revision 1, "Guidelines for 10 CFR 50.59 

Implementation," as endorsed by U.S. Nuclear Regulatory Commission (NRC) Regulatory 

Guide (RG) 1.187, "Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and 

Experiments" (ADAMS Accession No. ML003759710), when a licensee is requesting approval 

of a specific analysis for a specific application, a thorough understanding of the terms, 

conditions, and limitations relating to the application of the methodology is essential. This 

information is usually documented in the original license application or license amendment 

request. 

The NRC staff has reviewed the LAR and concluded that the following information is necessary 

to enable the staff to make an independent assessment regarding the acceptability of the 

proposed amendment in terms of regulatory requirements and the protection of public health 

and safety and the environment. 

1. Section 3.5.1 of Enclosure 1 to the August 1, 2016, letter notes that NextEra will use an 

empirical correlation developed via testing to correlate concrete elastic modulus 

measurements with the through-thickness expansion to date. This correlation is a 

unique, first-of-a-kind approach and is necessary for the proposed monitoring program to 

be effective. The staff needs additional information on the technical basis for the 

correlation. 

Provide the technical basis for the correlation between concrete elastic modulus and 

through-thickness expansion. Include enough data from the testing for the staff to make 

a decision on the adequacy of the correlation. 

Enclosure 
- 2 -

2. Section 3.3 of Enclosure 1 proposes a "building deformation assessment" process to 

evaluate ASR impacts on each of the seismic Category I structures listed in UFSAR 

Section 3.8.4.1. This method is a first-of-a-kind, complex analysis, that has not been 

previously reviewed by the NRC or by a consensus industry group. Therefore, in order 

to have a thorough understanding of the methodology, the staff needs to review at least 

one detailed demonstration of the process to provide reasonable assurance that the 

approach is appropriate and repeatable. 

Provide a demonstration of the building deformation assessment process being applied 

to a structure affected by ASR. The demonstration should include a structure that has 

gone through the entire process (i.e., through Stage Three). 

3. Section 3.3 of Enclosure 1 notes that the concrete backfill may apply pressure to 

adjacent structures; however, no explanation is provided regarding how this pressure will 

be estimated. 

Explain how the pressure from concrete backfill is determined. Also include an 

explanation of how external pressure due to concrete expansion will be determined for 

the case of two adjacent concrete structures. 

4. It is not clear to the NRC staff whether you are requesting approval to change your 

licensing basis to Regulatory Guide (RG) 1.92, Revision 3, "Combining Modal 

Responses and Spatial Components in Seismic Response Analysis," specifically 

changing from the square-root of sum-of-squares method to use the alternate 100-40-40 

approach. If so, provide a detailed explanation or example demonstrating how you are 

meeting the guidance in RG 1.92, Revision 3. 

5. Minimal information is provided about the ASR deformation program, and especially, 

how the status of the existing structures will be quantified. Section 3.3.2 notes that 

existing data will be reviewed, but no explanation is provided regarding how much data 

is necessary to determine whether a structure is impacted by ASR deformation (e.g., 

how many locations will be monitored, how recent the inspection data will be, what 

specific indications will be looked for when reviewing existing data). 

Provide a more detailed summary of the ASR deformation program. Include a detailed 

discussion of what will be looked at during the field data review and how deformations 

and strains will be conservatively estimated. The discussion should explain how 

monitoring elements will be determined, how it will be determined that existing data is 

representative of the structure, and how it will be determined that enough data has been 

collected to properly estimate the demands on the structure. In addition, an example of 

applying the initial screening process to an existing structure is needed that highlights 

the generic portions of the process and explains how they will be repeated for other 

structures. 
E. McCartney - 2 -

The information requested and associated timeframe in this letter were discussed with 

Mr. Ken Browne of your staff on September 14, 2016. 

If you have any questions, please contact me at (301) 415-2048 or Justin.Poole@nrc.gov. 

Docket No. 50-443 

Enclosure: 

Supplemental Information Needed 

cc w/enclosure: Distribution via Listserv 

DISTRIBUTION: 

PUBLIC 

LPLl-2 R/F 

RidsACRS_MailCTR Resource 

RidsNrrDeEmcb Resource 

RidsNrrDorl Resource 

RidsNrrDorllpl1-2 Resource 

RidsNrrLALRonewicz Resource 

RidsNrrPMSeabrook Resource 

RidsRgn1 MailCenter Resource 

ADAMS Accession No.: ML 16258A022 

Sincerely, 

IRA/ 

Justin C. Poole, Project Manager 

Plant Licensing Branch 1-2 

Division of Operating Reactor Licensing 

Office of Nuclear Reactor Regulation 

*by e-mail dated 

OFFICE NRR/DORL/LPL 1-2/PM NRR/DORL/LPL 1-2/LA NRR/DE/EMCB/BC(A)* 

NAME JPoole LRonewicz Yli 

DATE 9/16/2016 9/15/2016 9/8/2016 

OFFICE NRR/DORL/LPL 1-2/BC NRR/DORL/LPL 1-2/PM .< . ·. /.\f . • •<-,U' 

NAME DBroaddus JPoole ;¥:> 

DATE 9/19/2016 9/19/2016 :"\" T. .. \ '.>: 

OFFICIAL RECORD COPY