ML20350B827

(12/15/2020) E-mail from R. Guzman to S. Sinha - Acceptance Review Determination Proposed LAR to Revise MPS2 TSs for Steam Generator Inspection Frequency

ML20350B827
Person / Time
Site:	Millstone
Issue date:	12/15/2020
From:	Richard Guzman NRC/NRR/DORL/LPL1
To:	Sinha S Dominion Energy Nuclear Connecticut
Guzman R
References
EPID L-2020-LLA-0227
Download: ML20350B827 (4)

Text

From: Guzman, Richard To: Shayan Sinha Cc: Jeffry A Langan; Kathryn H Barret; RidsNRRLIC109 Resource; Danna, James

Subject:

Millstone Power Station, Unit No. 2 - Acceptance Review Determination Re: Proposed LAR to Revise the MPS2 TSs for Steam Generator Inspection Frequency (EPID L-2020-LLA-0227)

Date: Tuesday, December 15, 2020 6:54:00 PM Mr. Sinha, By letter dated October 8, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20282A594), as supplemented by letter dated December 8, 2020 (ADAMS Accession No. ML20343A259), Dominion Energy Nuclear Connecticut, Inc.

(DENC, the licensee) submitted a license amendment request (LAR) for Millstone Power Station, Unit No. 2 (MPS2). The proposed amendment would revise MPS2 TS 6.26, "Steam Generator (SG) Program," Item d.2, to reflect a proposed change to the required SG tube inspection frequency from every 72 effective full power months (EFPM), or at least every third refueling outage, to every 96 EFPM.

By e-mail communication on November 20, 2020 (shown below), the U.S. Nuclear Regulatory Commission (NRC) staff requested the licensee to supplement its LAR to address areas that did not meet the criterion of Sufficiency of Information described in Section 3.1.2 of LIC-109, Acceptance Review Procedures for Licensing Basis Changes, (ADAMS Accession No. ML20036C829). The licensee submitted its response to the information request on December 8, 2020.

The purpose of this e-mail is to provide the results of the NRC staffs acceptance review of the proposed licensing action. 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),

whenever a holder of an operating license under this part desires to amend the license, application for an amendment must be filed with the Commission fully describing 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, as supplemented, and concluded that it does provide technical information in sufficient detail to enable the NRC staff to complete its detailed technical review and 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. Given the lesser scope and depth of the acceptance review as compared to the detailed technical review, there may be instances in which issues that impact the NRC staffs ability to complete the detailed technical review are identified despite completion of an adequate acceptance review. If additional information is needed, you will be advised by separate correspondence.

Based on the information provided in your submittal, as supplemented, the NRC staff has

estimated that this licensing request will take approximately 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> to complete. The NRC staff expects to complete this review no later than December 2021. If there are emergent complexities or challenges in our review that would cause changes to the initial forecasted completion date (greater than a month) or significant changes in the forecasted hours (greater than 25%), the reasons for the changes, along with the new estimates, will be communicated during the routine interactions with the assigned project manager. These estimates are based on the NRC staffs initial review of the application and they could change, due to several factors including requests for additional information, unanticipated addition of scope to the review, and review by NRC advisory committees or hearing-related activities. Additional delay may occur if the submittal is provided to the NRC in advance or in parallel with industry program initiatives or pilot applications.

If you have any questions, please contact me.

Richard V. Guzman Senior Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission From: Guzman, Richard Sent: Friday, November 20, 2020 4:28 PM To: Shayan Sinha <Shayan.Sinha@dominionenergy.com>

Cc: Jeffry A Langan <jeffry.a.langan@dominionenergy.com>; Kathryn H Barret

<Kathryn.H.Barret@dominionenergy.com>

Subject:

Millstone Power Station, Unit No. 2 - Acceptance Review, Unacceptable with Opportunity to Supplement re: Proposed LAR to Revise the MPS2 TSs for Steam Generator Inspection Frequency (EPID L-2020-LLA-0227)

Mr. Sinha, By letter dated October 8, 2020 (ADAMS Accession No. ML20282A594), Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) submitted a license amendment request for Millstone Power Station, Unit No. 2 (MPS2). The proposed amendment would revise MPS2 TS 6.26, "Steam Generator (SG) Program," Item d.2, to reflect a proposed change to the required SG tube inspection frequency from every 72 effective full power months (EFPM), or at least every third refueling outage, to every 96 EFPM. The purpose of this communication 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 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 below 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 the licensee supplement the application to address the information requested below by December 10, 2020. This 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 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 staffs detailed technical review by separate correspondence.

The information requested and associated time frame in this letter were discussed with your staff on November 20, 2020.

If you have any questions, please contact me.

Richard V. Guzman Senior Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission OFFICE OF NUCLEAR REACTOR REGULATION ACCEPTANCE REVIEW - UNACCEPTABLE WITH OPPORTUNITY TO SUPPLEMENT PROPOSED LICENSE AMENDMENT REQUEST TO REVISE THE MPS2 TECHNICAL SPECIFICATIONS FOR STEAM GENERATOR INSPECTION FREQUENCY DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION, UNIT NO. 2 DOCKET NO. 50-336 By letter dated October 8, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20282A594), Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) submitted a license amendment request for Millstone Power Station, Unit No. 2 (MPS2). The proposed amendment would revise MPS2 TS 6.26, "Steam Generator (SG)

Program," Item d.2, to reflect a proposed change to the required SG tube inspection frequency from every 72 effective full power months (EFPM), or at least every third refueling outage, to every 96 EFPM. The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the proposed LAR does not meet the criterion of Sufficiency of Information described in section 3.1.2 of LIC-109, Acceptance Review Procedures for Licensing Basis Changes, (ADAMS Accession No. ML20036C829) in that sufficient technical information was not provided for the staff to complete its review of the proposed application as outlined below.

• The LAR states, Furthermore, the MPS2 SG operational assessment and experience supports the proposed TS changes. However, the operational assessment (OA) submitted by the licensee was for a three-cycle operating period which was developed at the completion of RFO24 in spring 2017 to demonstrate that the SG structural and accident induced leakage performance criteria would be met during the operating period preceding RFO27 in fall 2021. Also, the LAR does not provide a justification as to why an OA for a five-cycle operating period was not provided. To support the proposed LAR, the licensee is requested to supplement their LAR with a five-cycle operating period OA, to demonstrate that the SG structural and accident induced leakage performance criteria would be met during the operating period preceding RFO29 in fall 2024, for all existing and potential degradation mechanisms.

• Millstone Unit 2 currently has two existing degradation mechanisms - fan bar wear and foreign object (FO) wear.

o Section 3.11 in Attachment 1 of the LAR, includes five-cycle operating period information for fan bar wear and concludes there is reasonable assurance that the structural integrity performance criterion will be met for this mechanism for the five cycles of operation (at which time, another inspection and OA will be performed). Section 6.1 of the OA completed at the end of RFO24 concluded that there is reasonable assurance that the structural integrity performance criterion will be met for fan bar wear for the next three cycles of operation until 2R27, which is five total cycles of operation.

o Section 6.2 of the OA completed at the end of RFO24 concluded that there is reasonable assurance that the structural integrity performance criterion will be met for FO wear for a three-cycle operating period.

Section 3.9 in Attachment 1 of the LAR does not make a reasonable assurance statement that the structural integrity performance criterion will be met for FO wear for a five-cycle operating period. Therefore, neither the OA or the LAR makes a reasonable assurance statement that the structural integrity performance criterion will be met for a five-cycle operating period.

• Per Section 3.1.2, Technical Staff Criteria, in NRR-LIC-109, the information provided should support a comparison of the RLA to the licensees existing processes or programs, if applicable, with justification for the change. The licensees existing process would be to develop an OA for the operating period preceding the next SG inspection and as noted above, the licensee did not justify why an OA for a five-cycle operating period was not provided. Additionally, the licensee cites similar LARs requesting a SG inspection frequency change, including recent one-time changes to SG inspection frequencies. In each of these instances, the licensee submitted OAs for the operating period preceding the next inspection. Meaning, for example, if the licensee is requesting that the SG inspection frequency be changed to a five-cycle operating period, then the OA was for a five-cycle operating period.