ML21245A438

Supplemental Information Needed for Acceptance of Requested Licensing Action Amendment to Revise 120-Volt AC Vital Instrument Panel Technical Specification Requirements

ML21245A438
Person / Time
Site:	Seabrook
Issue date:	10/05/2021
From:	Justin Poole Plant Licensing Branch 1
To:	Coffey B NextEra Energy Seabrook
Poole J, NRR/DORL/LPLI, 415-2048
References
EPID L-2021-LLA-0131
Download: ML21245A438 (5)

Text

October 5, 2021 Mr. Bob Coffey Executive Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company NextEra Energy Seabrook, LLC Mail Stop: EX/JB 700 Universe Blvd.

Juno Beach, FL 33408

SUBJECT:

SEABROOK STATION, UNIT NO. 1 - SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF REQUESTED LICENSING ACTION RE:

AMENDMENT TO REVISE 120-VOLT AC VITAL INSTRUMENT PANEL TECHNICAL SPECIFICATION REQUIREMENTS (EPID L-2021-LLA-0131)

Dear Mr. Coffey:

By letter dated July 21, 2021 (Agencywide Documents Access and Management System Accession No. ML21202A238), NextEra Energy Seabrook, LLC (NextEra) submitted a license amendment request for Seabrook Station, Unit No. 1 (Seabrook). The proposed amendment request would revise Technical Specification (TS) 3.8.3, Onsite Power Distribution - Operating by increasing the Allowed Outage Time (AOT) for the 120-volt AC vital instrument panel inverters and establishing a new required action for two inoperable 120-volt AC vital instrument panel inverters of the same electrical train and related administrative changes. The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staffs 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 application for an amendment to a 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 request in terms of regulatory requirements for 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 September 22, 2021. This

B. Coffey will enable the NRC staff to begin its detailed technical review. If the information responsive to the NRC staffs request is not received by the above date, the application will not be accepted for review pursuant to 10 CFR 2.101, and the NRC will cease its 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 staffs detailed technical review by separate correspondence.

The information requested and associated time frame in this letter were discussed with Mr. Steve Catron of your staff on September 1, 2021.

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

Sincerely,

/RA/

Justin C. Poole, Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-443 cc: Listserv

Enclosure:

Supplemental Information Needed

SUPPLEMENTAL INFORMATION NEEDED AMENDMENT REQUEST REGARDING REVISING 120-VOLT AC VITAL INSTRUMENT PANEL TECHNICAL SPECIFICATION REQUIREMENTS NEXTERA ENERGY SEABROOK, LLC SEABROOK STATION, UNIT NO. 1 DOCKET NO. 50-443 By letter dated July 21, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21202A238), NextEra Energy Seabrook, LLC (NextEra) submitted a license amendment request for Seabrook Station, Unit No. 1 (Seabrook). The proposed amendment request would revise Technical Specification (TS) 3.8.3, Onsite Power Distribution

- Operating by increasing the Allowed Outage Time (AOT) for the 120-volt AC vital instrument panel inverters and establishing a new required action for two inoperable 120-volt AC vital instrument panel inverters of the same electrical train and related administrative changes. The proposed license amendment request is submitted following the guidance in Regulatory Guide (RG) 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decision-making:

Technical Specifications (ADAMS Accession No. ML100910008).

Regulatory Basis Section 2.3.2, Scope of the Probabilistic Risk Assessment for Technical Specification Change Evaluations, of RG 1.177, Revision 1, states that:

The scope and the level of PRA necessary to fully support the evaluation of a TS change depend on the type of TS change being soughtHowever, in some cases, a PRA of sufficient scope may not be available. This will have to be compensated for by qualitative arguments, bounding analyses, or compensatory measures.

The scope of the analysis should include all hazard groups (i.e., internal events, internal flood, internal fires, seismic events, high winds, transportation events, and other external hazards) unless it can be shown that the contribution from specific hazard groups does not affect the decision. When the risk associated with a particular hazard group or operating mode would affect the decision being made, it is the Commission's policy that, if a staff-endorsed PRA standard exists for that hazard group or operating mode, then the risk will be assessed using a PRA that meets that standard.

Section 2.3.3.1, Detail Needed for Technical Specification Changes, of RG 1.177, Revision 1, states that:

If the PRA does not model the system for which the TS change is being requested, specialized analyses may be necessary when requesting changes to the TS for these systems.

Enclosure

Identified Insufficiencies in Application The insufficiencies identified by the NRC staff during its acceptance review of the application are provided below.

PRA Technical Adequacy and Scope of Risk Assessment

1. Missing information on peer review history and results for the fire and seismic PRAs supporting the application, including disposition of any open finding level Facts and Observations (F&Os).

2. In case the fire and seismic PRAs supporting this application are not peer reviewed per the guidance in RG 1.200, Revisions 2 or 3,

a. Missing detailed description of the pedigree of the fire and seismic PRA and/or analyses in Seabrook Station Probabilistic Safety Study, 2014 Update, SSPSS-14,

b. Missing justification for the appropriateness of using these non-peer reviewed PRAs, including the corresponding risk estimates, to support this application.

3. Missing discussion of assumptions and sources of uncertainty for fire and seismic PRAs and/or analyses supporting this application.

4. Missing details of the bounding analysis for fire and seismic risk, including justification that the selected approach is bounding for this application given (i) the need to modify the Internal Events model of record, (ii) the reported dominance of fire and seismic risk for this application, (iii) potential technical adequacy challenges, and (iv) potential uncertainties in the fire and seismic analysis.

5. Missing description of the new baseline risk metrics considering the bounding evaluation.

6. Missing discussion of consideration of external hazards other than fire and seismic, including the basis for any conclusions that contributions from specific hazard groups do not affect this application.

Justification for Requested AOTs

7. Missing discussion of risk impact and conclusion for the proposed 8-hour AOT for the condition of two inoperable vital instrument panels of the same train.

8. Missing justification for the 14-days extended AOT for 1E & 1F inverters vs. 7-days for 1A, 1B, 1C & 1D inverters.

ML21245A438 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DRA/APLB/BC NAME JPoole KZeleznock SVasavada DATE 10/05/2021 10/05/2021 08/18/2021 OFFICE NRR/DORL/LPL1/BC NRR/DORL/LPL1/PM NAME JDanna JPoole DATE 10/05/2021 10/05/2021