ML20023D037

Request for Additional Information (E-mail Dated 1/23/2020) Proposed LAR to Revise TS 3.8.1.1, AC Sources Operating

ML20023D037
Person / Time
Site:	Millstone
Issue date:	01/23/2020
From:	Richard Guzman NRC/NRR/DORL/LPL1
To:	Sinha S Dominion Energy Nuclear Connecticut
Guzman R
References
EPID L-2019-LLA-0177
Download: ML20023D037 (4)

Text

From: Guzman, Richard To: Shayan.Sinha@dominionenergy.com

Subject:

Millstone Power Station, Unit No. 2 - Request for Additional Information regarding proposed LAR to revise TS 3.8.1.1, A.C. Sources - Operating) (EPID: L-2019-LLA-0177)

Date: Thursday, January 23, 2020 6:11:13 AM

Shayan, On December 30, 2019, the U.S. Nuclear Regulatory Commission (NRC) staff sent Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) the subject Request for Additional Information (RAI) as a draft (via e-mail shown below). This RAI relates to the license amendment request (LAR) submitted by DENC (ADAMS Accession No. ML19234A111), as supplemented by letter dated October 22, 2019 (ADAMS Accession No. ML19304A294), proposing to revise Millstone Power Station, Unit 2 Technical Specifications (TSs). Specifically, the proposed LAR would revise TS 3.8.1.1, A.C.

[alternating current] Sources - Operating, to add a new permanent Required Action a.3, that would provide an option to extend the allowed outage time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 10 days for one inoperable offsite circuit. A one-time exception to the new proposed Required Action a.3 is also proposed which would extend the AOT to 35 days for one inoperable offsite circuit.

On January 16, 2020, the NRC staff conducted a conference call with the licensee staff to clarify the request. Following the discussion, you indicated that DENC will provide a response to this RAI within 30 days from the issuance of the RAI; therefore, the NRC staff expects DENCs formal response by February 24, 2020. Updated below is the official (final) RAI. A publicly available version of this e-mail and RAI will be placed in the NRCs ADAMS system. Please contact me should you have any questions in regard to this request.

Sincerely,

~~~~~~~~~~~~

Rich Guzman Sr. PM, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov From: Guzman, Richard <Richard.Guzman@nrc.gov>

Sent: Monday, December 30, 2019 12:38 PM To: Shayan Sinha (Generation - 6) <Shayan.Sinha@dominionenergy.com>

Subject:

[External] RE: Millstone Unit 2 - DRAFT Request for Additional Information and Plan for Audit (LAR re: TS 3.8.1.1, A.C. Sources - Operating) [EPID: L-2019-LLA-0177)

Shayan, Shown below is an additional draft RAI related to proposed TS 3.8.1.1. Please include it for

discussion during our clarification call.

Thanks, Rich

================================

By letter dated August 17, 2019, Dominion Energy Nuclear Connecticut, Inc. (DENC), the licensee, submitted a license amendment request to revise Millstone Power Station Unit 2 (MPS2) Technical Specifications (TS) (ADAMS Accession No. ML19234A111). The requested changes revise TS 3.8.1.1, A.C. [alternating current] Sources - Operating, to add a new Required Action a.3, that provides an option to extend the allowed outage time (AOT) from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 10 days for one inoperable offsite circuit. In the application the licensee states:

This new Required Action is needed to complete periodic maintenance and testing of the Millstone Power Station Unit 3 (MPS3) A Reserve Station Service Transformer (RSST) and other 345 kilovolt (kV) south bus switchyard components. Since periodic maintenance and testing of these components cannot typically be completed within the current 72-hour AOT, adoption of an extended AOT reduces: 1) the number of switching evolutions required to complete the work, 2) equipment unavailability time, and 3) potential for equipment failures or human performance events. Use of this 10-day AOT will be limited to no more than once per 18 month refueling interval for MPS3.

The licensee proposes a one-time allowance to the new proposed Required Action a.3 that extends the AOT to 35 days for one inoperable offsite circuit and states that use of the 35-day AOT allows replacement of the MPS3 'A' RSST, its associated equipment, and other 345 kV south bus switchyard components that are nearing the end of their dependable service life. The licensee stated that this work is planned to take place no later than the fall 2023 outage for MPS3 (3R22) and that the replacement of these components is necessary to ensure continued safe and dependable generation of electric power.

Additionally, the licensee states that the permanent 10-day AOT and one-time 35-day AOT will only be entered if the conditions specified in TS Required Action a.3 are met and that certain compensatory and risk management actions will be met during both the permanent 10-day AOT and the one-time 35-day AOT which are provided in the TS Bases in support of this amendment request.

Regulatory Analysis Basis

1. Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(b) requires each license authorizing operation of a production or utilization facility of a type described in § 50.21 or § 50.22 will include technical specifications. The technical specification will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant to § 50.34.

2. The NRC staffs guidance for review of TSs is in Chapter 16, Technical Specifications,

of NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants (SRP), dated March 2010 (ADAMS Accession No. ML100351425). As described therein, as part of the regulatory standardization effort, the NRC staff has prepared standard TS for each of the light-water reactor nuclear designs.

Proposed TS 3.8.1.1 In letter dated August 14, 2019, the following change was proposed for TS 3.8.1.1 (added text is italicized and bolded).

Inoperable Equipment Required ACTION

a. One offfsite circuit a.1 Perform Surveillance Requirement 4.8.1.1.1 for remaining offsite circuit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> prior to or after entering this condition, and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter.

AND a.2 Restore the inoperable offsite circuit to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (within 10 days if Required ACTION a.3 is met) or be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

AND a.3 With the MPS3 A RSST inoperable and the MPS3 A NSST energized with breaker 15G-13T-2 (13T) and associated disconnect switches closed, restore either offsite circuit to OPERABLE status within 10 days* if the following requirements are met:

- Within 30 days prior to entering the 10-day AOT, the availability of the supplemental power source shall be verified.

- During the 10-day AOT, the availability of the supplemental power source shall be checked once per shift. If the supplemental power source becomes unavailable at any time during the 10-day AOT, restore to available status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

• To facilitate replacement of the MPS3 A RSST and associated equipment, use of a one-time 35-day allowed outage time is permitted provided the requirements of Required ACTION a.3 are met. The work shall be completed no later than the end of MPS3 Refueling Outage 22 (fall 2023).

Request for Additional Information #1 (Proposed TS 3.8.1.1)

Required Action a.2 has an added parenthetical statement (within 10 days if Required Action a.3 is met) which allows an extension of the AOT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 10-days. New Required Action a.3 requires restoration of either offsite circuit to operable status within 10-days and the 10-day AOT has an associated footnote denoted by *. Footnote

• allows the 10-day AOT to be extended to 35-days, one time only, to facility replacement of the MPS3 A RSST and associated equipment provided the requirements of Required Action a.3 are met.

Required Action a.3 allows the 10-day AOT to be extended via footnote *; however, Required Action a.2 does not allow the 10-day AOT to be extended because footnote

• is not applied to the 10-day AOT referenced in Required Action a.2. TS 3.8.1.1 as currently proposed, does not allow use of the one-time AOT extension to 35-days in footnote

• because Required Actions a.2 and a.3 conflict with each other. In addition, it is not clear that the supplemental power source requirements in Required Action a.3 applies when the AOT is extended to 35-days via footnote *.

Provide a resolution to the conflict between Required Actions a.2 and a.3 in TS 3.8.1.1 and provide clarity in TS 3.8.1.1 Required Action a.3 that the supplemental power source requirements apply when the AOT is extended to 35-days via footnote *.